Grundwasserneubildung und ihre Ermittlung – eine Anmerkung zum Beitrag von Hölting: Modellrechnungen zur Grundwasserneubildung

Ohne Zusammenfassung Eingang des Beitrages: 23.04.97     

A review of the development and application of microalloyed medium carbon steels

Microalloyed medium-carbon steels with ferrite-pearlite microstructure were developed in the FRG in early 1972, with the primary aim of saving the cost of heat treatment. A steel with roughly 0.47% C, 0.75% Mn, 0.060% S and 0.1 % V was first used for crankshafts in cars manufactured by one of the largest European automobile companies. The effect of microalloying elements such as vanadium and niobium (niobium instead of columbium is used in this paper) in these steels and their dependence on the cooling rate from drop-forging temperatures is reviewed. Although niobium is more effective than vanadium, it leads to problems while manufacturing these steels with ~0.47% C, due to the high solution temperature of the niobium precipitates, so that preference has been given to vanadium. Further development work carried out to improve the ductility of these steels is reported. Steel compositions, which could make these steels applicable for various automobile and other engineering components, are presented.     

Kommentar II

Ohne Zusammenfassung     

ta‐C beschichtete Werkzeuge für die Trockenumformung von Aluminiumblechen

ta‐C coated tools for dry forming of aluminum sheets The suitability of ta‐C coated tool surfaces for sheet forming of aluminum alloys was examined by strip‐draw testing. It was shown that ta‐C coatings, which are known as DLC coatings with superior wear resistance are also favourable concerning the anti‐adhesive behaviour. In attempts with AlMg5Mn‐ as well as Al99Mg1‐sheet materials several hundred sheets could be formed without noticeable aluminum adhering at the ta‐C coated tool surface. Neither the coefficients of friction nor the surface qualities of the aluminum sheets worsened during the observed period. Compared with tests of uncoated tools in combination with lubricants, the dry ta‐C coated tool behaves comparable with a good lubricant. In a real clinch test with aluminum sheets the positive results from strip‐draw experiments were confirmed. Using ta‐C coated clinching stamps and no lubricants a large number of clinching processes could be performed without noticeable adhering and increase of stripping forces.     

On the demand for preventive care

This paper analyzes the demand for preventive care in an optimal control model in which utility is not contingent on the state of health and preventive measures are taken against future costs of curative care. It turns out that the demand for preventive care depends negatively on its price, and positively on the price of curative care and on the life-span. The influence of the depreciation rate on health capital is ambiguous. While the sign of the income elasticity cannot be determined in general, it may be positive if income is negatively correlated with the rate of time preference.     

Cui bono? — Ziele und Inhalte eines Datenschutz-Zertifikats

Um ein Datenschutz-Zertifikat zur Best?tigung eines hohen Datenschutz-Niveaus erfolgreich zu etablieren, müssen die Randbedingungen stimmen. Ausgehend vom Informationsbedarf m?glicher Zielgruppen an ein solches Zertifikat begründet der Beitrag die Datenschutzorganisation als Prüfgegenstand und stellt die aus der Sicht der Autoren wichtigsten Inhalte der Prüfung vor.     

Carbon print studies for the energy conservation regulations of the UK and China

The recently published building energy conservation regulation of China (GB50189-2005, 2005 [1]) was compared with the latest UK building energy conservation regulation (Part L) (Building Regulation Approved Document L2A, 2006 [2]). The UK regulation appeared stricter in its requirements and standards than the Chinese regulation. In two case studies, the design of a sample building is altered to fulfil the minimum requirements of the two regulations. The energy consumption and Carbon print of the virtual building under the two set of regulations are estimated by computer based models in the two case studies based on a building in the Cold regions. The building under the UK regulation showed higher energy efficiency and less Carbon emissions per year. The high level estimate in the case studies discovered a potential energy savings of 29% by strengthening the design requirements in the Chinese regulation to the UK level. The improvement on energy efficiency of buildings can be achieved in strengthening the proactive design aspects on building envelope, efficient HVAC, lighting and lighting control system. The software used was SBEM which is the default tool in the UK Part L regulation.