The dynamics of aging and rehabilitation following coronary bypass operation]

The dynamics of aging encompass the topics "aging of society" and "coping with chronic illness". Both are discussed using data from a qualitative study on return to work after coronary artery bypass surgery. Data from the retrospective substudy reveal four forms of aging as biographical development toward early retirement, old-age retirement, or related stages. It emerges that the manner of aging is less influenced by medical rehabilitation or medical history, and more by the patient's occupation and socio-economic status. Case reports are used to show that social class is a facilitation context, but not a determining force, regarding the choice between postoperative retirement or return to work. The final section briefly discusses whether the findings concerning the dynamics of aging of the cohort operated on in the late 1970s apply also to that of the cohort operated on in the late 1980s; this is addressed using some data from the prospective sub-study.     

Some techniques for solving linear equation systems with guarantee

Methods are described for solving a system of linear equations with error bounds. Rectangular and spherical intervals ofR ⁿ are used combined. The objective is to get guaranteed accuracy with a minimal effort of computing time.     

Effect of Phase-Selective Nanoscale Precipitates on the Bauschinger Effect in Austenitic–Ferritic Duplex Stainless Steels

Metallurgical and Materials Transactions A - The Bauschinger effect in austenitic–ferritic duplex stainless steel 1.4462 was investigated using tension–compression tests combined with...     

The inhibitive effect of extraneous ion addition on stress corrosion cracking of alpha-brass

The addition of ammonium chloride, cobalt sulphate, cesium sulphate and ethylene diamine to a Mattsson solution and the addition of ammonium sulphate to the Pugh solution have been found to produce an inhibitive effect on the stress corrosion cracking of alpha-brass in these solutions. Ammonium chloride and ammonium sulphate additions affect the tarnish formation on the specimen as well as the cracking pattern. Electrochemical polarization studies have also been carried out with these two additives. The observations have been explained in the light of adsorption of these ionic species at selected sites on the metal surface and their possible interference with the cathodic reactions.     

Towards improved design of boring bars part 1: Dynamic cutting force model with continuous system analysis for the boring bar performance

The vibrational amplitude is generally large in the case of a boring bar due to its slenderness. A dynamic cutting force model has been presented to take this large amplitude into account. The boring bar is then modelled as a cantilever with this dynamic force acting at the free end and a generalized continuous system model is obtained. This model is solved for the specific case of boring with a zero side cutting edge angle for which published results are available. A reasonably close agreement is found between the proposed model and the experimental results.     

Coordination polymers of Zn(II) and N,N'-bis (carboxymethyl) dithiooxamide

Summary Coordination polymers were synthesized using N,N'-Bis (carboxymethyl) dithiooxamide (NN' CMDTO) and Zinc(II) salts. The complexes were characterized by elemental analyses, IR spectral studies, TGA and viscosity measurements. In the proposed structures the ligand was supposed to be coordinated to metal through sulphur and oxygen.     

Bücherschau

Ohne Zusammenfassung VDI     

Carbon Aerogels as Electrode Material in Supercapacitors

Due to their large specific surface area and their high electrical conductivity carbon aerogels are promising materials for electrodes in electrochemical double-layer capacitors (supercapacitor). The carbon aerogels were made via pyrolysis of resorcinol formaldehyde aerogels. The latter were prepared by supercritical and subcritical drying as well. The important findings of our investigation were, that the highest capacities of 46 F/cm³ were measured for samples with a density of about 800 kg/m³ pyrolyzed at 800°C. Also it was shown that RF-gels with molar resorcinol/catalyst ratios 1000 or higher can be dried subcritically without cracking or significant shrinkage. Carbon aerogels derived from these RF-aerogels have a small mesopore surface area, however an especially large micropore area. They provide electrical capacities which are most suitable for their use in supercapacitors.