Does precontemplation represent a homogeneous stage category? A latent class analysis on German smokers.

The authors examined the subtype structure of smokers classified in the precontemplation stage of change within the transtheoretical model. From a general practice-based sample of 1,499 daily smoking patients from Germany (participation rate 80%), they used a subgroup of 929 smokers who were classified in the precontemplation stage and applied latent class analysis, using the pros and cons of nonsmoking and smoking cessation self-efficacy as the defining variables. Cross-sectional validation of the emerging classes was based on smoking behavior and processes of change variables. For longitudinal validation, generalized estimation equation analyses were used on motivational and abstinence criteria from 6-, 12-, 18-, and 24-month follow-ups. A 4-class model best represented the data. Three subtypes (labeled progressive, immotive, and disengaged pessimistic) were similar to clusters identified in U.S. studies. The 4th (disengaged optimistic), by contrast, was reminiscent of a type that had previously only emerged in a Dutch study. Cross-sectional and longitudinal validation results confirmed the distinctiveness and predictive power of the classes. The findings highlight the importance of tailoring interventions for smoking behavior change to the needs of different subgroups of precontemplating smokers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sliding wear of an unlubricated frictional combination of ductile metal and brittle abrasive

The concept of determining wear from hypotheses concerning shear effects in metal surface regions was applied to the sliding wear of a smooth elastoplastically deformable metal substance and a rough brittle abrasive. Interfacial layers or lubricating depositions on either surface were neglected. The form of the contact was modelled using random fields for the roughness profiles. The resulting intensities of wear may be compared with published experimental results. The wear intensity level was quantitatively determined. Dependence on the nominal pressure and properties of the rough abrasive is thus explained. Instead of hardness the compressive strength of abrasive peaks is the dominant characteristic parameter.     

The wet corrosion of molybdenum thin film – Part III: The effect of Ti and Nb

Magnetron sputtering has become the process of choice for the deposition of a wide range of industrially important coatings. Over the last decade, interest in molybdenum thin films prepared by magnetron sputtering has been increasing; however, little research has been done on molybdenum‐titanium and molybdenum‐niobium alloy thin films. During the current study, electrochemical impedance spectroscopy (EIS) was employed to investigate the effect on the corrosion resistance in basic chloride environments of adding titanium and niobium species to molybdenum thin films deposited by physical vapor deposition. The results indicate that the MoTi alloy thin films exhibit better protective properties than either the molybdenum‐niobium alloy or unalloyed molybdenum thin films.     

The whispered voice: the best test for screening for hearing impairment in general practice?

Hearing loss is an important health problem in the elderly which sometimes leads to social isolation. In a study with 62 patients, the diagnostic value of four simple tests for screening for hearing loss in general practice was examined. When paying attention to the loudness of the whispering, the whispered voice test can be a valuable test for assessment of hearing loss in general practice.     

Das verhalten von copolymeren aus styrol und acenaphthylen bei der einwirkung von licht,I

A series of styrene and acenaphthylene copolymers were prepared by thermal polymerization at 100°C. Films of copolymers with various contents of acenaphthylene were exposed to light in an apparatus (Xenotest) under the atmosphere of normal air and in some cases under nitrogen. The degradation of copolymers was followed by measurements of solution viscosity. Copolymers with small contents of acenaphthylene (4,2 mol-%) show slower degradation than polystyrene up to exposure times of about 80 h, but then a stronger degradation takes place with increased content of acenaphthylene. In the presence of oxygen the formation of benzene-insoluble particles besides degradation was observed. The amount of these “benzene-insoluble” particles, which have a specific absorption in the infrared at 1730 cm ^–1, depends upon the exposure time and the content of acenaphthylene. No such benzene-insoluble products were found if the films were exposed to light in the same apparatus under nitrogen atmosphere.     

A test particle Monte Carlo method

A Monte Carlo technique was developed suitable for investigating rarefield gas dynamics problems. The procedure is based on the ‘test particle’ method. The discontinuous function frequently employed for describing the target molecules' velocity distribution is replaced here by a continuous analytic function, the form of calculations. This modification simplifies the calculations, reduces the computer storage requirements, and facilities the application of the method to multi-dimensional problems. The accuracy and versatility of the technique was evaluated by obtaining solutions to several one dimensional problems for which other results exist.