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This contribution presents an extensive performance evaluation of metakaolin-based geopolymer and calcium aluminate mortars during a long-term field exposure to a wastewater system exhibiting intensive microbially induced acid corrosion (MIAC) conditions. Results were compared to a high-performance OPC concrete, typically used for manhole fabrication. Field conditions were obtained by monitoring relative humidity, temperature, H2S and CO2. Microstructural degradation and elemental distributions within each binder type over time were recorded by electron probe microanalysis, X-ray diffraction and pH-imaging techniques, together with specimen's mass and surface-pH characterization. Microbiome and epifluorescence analyses indicated exposure-time dependent alternating bacterial community structures within the materials. Clear differences regarding bacterial species distribution and biodiversity were observed for the different binder types. Estimated corrosion rates were the lowest (1.4 mm/a) and the highest (13.3 mm/a) for the tested geopolymer formulations, pointing out that only well designed geopolymer materials may provide an improved MIAC resistance.

Background: Cognitive behavioral therapy for psychosis (CBTp) is a specific form of psychotherapy recommended in evidence-based treatment guidelines for patients with psychosis. However, it remains unclear whether CBTp is more efficacious than unspecific psychotherapies such as supportive therapy (ST). Methods: This multicenter, single blind, randomized clinical trial used a parallel group design to compare CBTp and ST. In total, 330 patients with persistent positive symptoms were included. Participants received 20 sessions of CBTp or ST over a 9-month period. Therapy was provided in six outpatient clinics at university psychiatry departments. The primary endpoint was the severity of positive symptoms (Positive and Negative Syndrome Scale-positive) until post-treatment at 9 months after inclusion. Analysis was carried out by intention to treat with multilevel linear modeling. Findings: There was a between group effect size of g=0·33 (0·11-0·55) in favor of CBTp for positive symptoms, with pre-post effect sizes of g=0·93 (0·70-1·15) for CBTp and g=0·62 (0·40-0·84) for ST. CBTp showed favorable effects for hallucinations and social functioning, but not for negative symptoms and readmission rates. Ratings of the therapeutic relationship, number of adverse events, and antipsychotic medication did not differ between the groups. Positive symptoms decreased in both groups until the 24 month follow-up, with a between group difference of g=0·09 (-0·23-0·39). Interpretation: CBTp is more efficacious than ST in patients with persistent positive symptoms. CBTp effects cannot be explained by therapeutic attention alone. This indicates CBTp has specific mechanisms of action, and further supports the unrestricted recommendation of CBTp for the treatment of psychosis. Trial Registration Number: ISRCTN29242879 Funding Statement: The study was funded by the German ministry of education and research (grant no. 01GV0618). Declaration of Interests: All authors declare that there is no conflict of interest. Ethics Approval Statement: The study protocol was reviewed without objections by the ethics committee of the coordinating study center and the local ethics committees of all participating centers. Patients were included in the study after written informed consent was obtained, which was assured by external monitoring.

Microbial Baeyer-Villiger oxidations of representative mesomeric ketones with recombinant Escherichia coli cells expressing two monooxygenases from Brevibacterium were investigated. The two enzymes displayed enantiodivergent biotransformations on an array of structurally diverse substrates, allowing access to some key lactone intermediates in natural compound synthesis.

The laminated object manufacturing (LOM) process is an effective rapid prototyping technology with a variety of application possibilities. Applying LOM in rapid tooling and patternmaking is especially advantageous because of the LOM objects' robustness, their wood-like properties and their comparably low material costs. Possible fields of application are shown in the following. Explicit application examples in sand casting, investment casting and ceramics processing show how a reduction of necessary process steps and cycle times can be achieved by the application of LOM models. To gain this the control of the LOM objects' accuracy and stability during different secondary processes is of decisive importance.

The synthesis of carbo- and heterocyclic aldehydes bearing an ipso-methoxy group is investigated. The synthetic sequence is based on an initial Grignard addition of an olefin to a cyclic ketone followed by methylation of the resulting tertiary alcohol. The terminal olefin serves as precursor for the aldehyde functionality. Oxidation by ozonolysis turned out to depend significantly on the distance of the donor methoxy group. The observed side reactions could be circumvented by applying a one-pot OsO4 mediated diol formation followed by Malaprade oxidation using KIO4. A series of carbo- and heterocyclic precursors were successfully converted to the title products.

Thermographic measurements of a high-speed cutting process have been performed with an infrared camera. To realize images without motion blur the integration times were reduced to a few microseconds. Since the high tool wear influences the measured temperatures a set-up has been realized which enables small cutting lengths. Only single images have been recorded because the process is too fast to acquire a sequence of images even with the frame rate of the very fast infrared camera which has been used. To expose the camera when the rotating tool is in the middle of the camera image an experimental set-up with a light barrier and a digital delay generator with a time resolution of 1 ns has been realized. This enables a very exact triggering of the camera at the desired position of the tool in the image. Since the cutting depth is between 0.1 and 0.2 mm a high spatial resolution was also necessary which was obtained by a special close-up lens allowing a resolution of app. 45 microns. The experimental set-up will be described and infrared images and evaluated temperatures of a titanium alloy and a carbon steel will be presented for cutting speeds up to 42 m/s.

A fiber optic two-color pyrometer has been developed at the Institute of Heat Transfer and Air Conditioning at RWTH Aachen to measure temperatures at surfaces with low emissivities with a high time and space resolution. A fused silica fiber is used to transmit the radiation to the pyrometer from measuring positions with limited optical access. The two-color principle allows accurate measurements of absolute temperatures of surfaces with unknown emissivities if the assumption of a gray body behavior at the measurement wavelengths is valid. The minimum temperature which can be measured with the pyrometer is limited due to the small radiation energy at low temperatures given by Planck's law, the emissivity of the body and the size of measurement area. At present temperatures of low emissivity metallic surfaces with sizes of 0.4 mm can be measured down to 250 degree(s)C. A new application to measure temperatures during high speed turning required a time resolution above the maximum of 2 microsecond(s) . To enhance the time resolution of the pyrometer the electronics was modified and a 30 MHz data acquisition board has been applied to the system. With this configuration a nanosecond time resolution is possible but the minimum measurable temperature increases. Different aspects for the limitation of the time resolution will be discussed. A new set-up with a nanosecond spark-flashlight will be described for the test of the transient response of the pyrometer and some test measurements will be presented.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.