LEAN PANEL BENDER – Einige mechanische Aspekte der Modellierung in Echtzeit für Produktion in Losgröße 1

Nachfolgend werden einige wissenschaftliche Aspekte der Echtzeit-Materialerkennungsstrategie MAC diskutiert, die in der neuen Maschinenfamilie LEAN PANEL BENDER der Firma Salvagnini Maschinenbau realisiert ist und die eine hochpräzise und hocheffiziente Herstellung von komplex geformten Blechprodukten sowohl bei Losgröße 1 als auch in der Serie erlaubt.(VLID)342339

Advanced mechanical simulation models for automatic panel benders

With automatic panel benders complete products are manufactured from sheet metal. In order to achieve short cycle times with high flexibility, a deep insight into the non-linear bending process is required. For this reason, efficient mechanical simulation models have been implemented, combining Finite Element Method, multibody dynamics simulation tools, contact mechanics algorithms and substructuring. Scope of this work is the comparison of several simulation models with measurement results performed on a Salvagnini P4XeD automatic panel bender

Industrial application of advanced adaptive concepts for automatic panel benders

Recently, the requirements on sheet metal production processes have increased significantly. Highest precision and flexibility with efficient energy consumption and short cycle times can be achieved by advanced concepts only. This requires a deep insight into the non-linear bending process. For this sake, efficient simulation models have been implemented to model the bending process: two and three dimensional finite element models combined with multibody simulation tools, contact mechanics algorithms and substructure techniques. The simulation tools have been successfully calibrated by measurement results. With the obtained detailed process knowledge, new adaptive concepts have been introduced, e.g. a smart crowning system in order to achieve straight profiles. The industrial application has shown the advantage of utilizing the above mentioned techniques. The straightness of the bends has been significantly increased, while energy consumption and cycle times have been reduced. Secondly, the development time of new machine concepts has been drastically reduced, such that the first prototype can be transferred to series production within short time. Moreover, the applied strategies show a large potential for future developments

Evaluation of Phytoavailability of Heavy Metals to Chinese Cabbage ( Brassica chinensis

This study compared the extractability of Cd, Cu, Ni, Pb, and Zn by 8 extraction protocols for 22 representative rural soils in Taiwan and correlated the extractable amounts of the metals with their uptake by Chinese cabbage for developing an empirical model to predict metal phytoavailability based on soil properties. Chemical agents in these protocols included dilute acids, neutral salts, and chelating agents, in addition to water and the Rhizon soil solution sampler. The highest concentrations of extractable metals were observed in the HCl extraction and the lowest in the Rhizon sampling method. The linear correlation coefficients between extractable metals in soil pools and metals in shoots were higher than those in roots. Correlations between extractable metal concentrations and soil properties were variable; soil pH, clay content, total metal content, and extractable metal concentration were considered together to simulate their combined effects on crop uptake by an empirical model. This combination improved the correlations to different extents for different extraction methods, particularly for Pb, for which the extractable amounts with any extraction protocol did not correlate with crop uptake by simple correlation analysis

Similarity methods in elasto-plastic beam bending

In industrial metal forming processes a large number of parameters has to be considered. As is well known, this number can be reduced by a non-dimensional representation. Based on the example of an elasto-plastic cantilever beam, the non- dimensional form is derived in the framework of the Bernoulli-Euler theory. In the second step, a Finite Element analyis of a drop-test experiment is performed, and the results are presented in non-dimensional form. The results illustrate the advantage of the normalization

Quicklime application instantly increases soil aggregate stability

Agricultural intensification, especially enhanced mechanisation of soil management, can lead to the deterioration of soil structure and to compaction. A possible amelioration strategy is the application of (structural) lime. In this study, we tested the effect of two different liming materials, ie limestone (CaCO3) and quicklime (CaO), on soil aggregate stability in a 3-month greenhouse pot experiment with three agricultural soils. The liming materials were applied in the form of pulverised additives at a rate of 2 000 kg ha1. Our results show a significant and instantaneous increase of stable aggregates after quicklime application whereas no effects were observed for limestone. Quicklime application seems to improve aggregate stability more efficiently in soils with high clay content and cation exchange capacity. In conclusion, quicklime application may be a feasible strategy for rapid improvement of aggregate stability of fine textured agricultural soils.(VLID)224292

Konstruktionsprobleme kombinierter Währungsklauseln

Problems in the Construction of Combined Currency Clauses In combined currency clauses, the monetary value of a claim is defined by cumulative amounts of various currencies. The object of such clauses is orientation of the monetary value of a claim to the changing values of several currencies in order to reduce the interests of creditors (minimization of inflation loss) and debtors (maximization of inflation gain) to a common denominator. Special interpretation problems arise when it is impossible to deduce from the clause’s definition the legal consequences which arise from the following changes in the political and monetary policy constraints affecting a specific clause: 1. One of the currencies listed in a clause is formally replaced in the course of a national currency reform by a currency with a different designation: In this respect, it is shown that the necessary conversion ruling is not a specific problem of combined currency clauses. But in order to allow for that conversion in the formulation of the clause, an explicit adjustment ruling is recommended for all combined currency clauses. 2. Several currencies listed in a clause are merged into or replaced by a single currency in the course of the implementation of a currency union: Regardless of the number of listed currencies affected, it is recommended, not on economic grounds, but certainly in the interests of legal clarity, that the following explicit adjustment ruling be adopted. In the event that one, several or all currencies listed in a clause are affected by a merger of national currencies into a community currency, the relative currency amounts must be converted into the community currency at the official conversion rate on the effective date of the community currency. 3. One or more of the currencies listed in a clause become invalid, as a result, say, of the dissolution of the issuing states: To ensure legal clarity for this case, too, it is advisable to include a clause which permits just, subsequent settlement of the proportional value of the invalid currency. 4. One or more of the currencies listed in a clause become economically practically valueless in consequence of enormous inflation rates: For this case it is shown that the proportional value of a currency so seriously affected by inflation becomes ever smaller, to the benefit of the proportional values of the other currencies. If we reckon with only a limited number of decimal places, its proportional value will decline to finite 0. From the legal standpoint, no modification of the clause is necessary

Soil and phosphorus redistribution along a steep tea plantation in the Feitsui reservoir catchment of northern Taiwan

[[sponsorship]]環境變遷研究中心[[note]]已出版;[SCI];有審查制度;具代表性[[note]]http://gateway.isiknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=Drexel&SrcApp=hagerty_opac&KeyRecord=0038-0768&DestApp=JCR&RQ=IF_CAT_BOXPLO