Oxidation behaviour of a Mo(Si,Al)2 based composite at 1500 °C

The oxidation of a Mo(Si,Al)₂ composite is investigated at 1500 °C in dry air using exposure times from 1 to 1000 h. Cross sections are examined with Scanning Electron Microscopy (SEM) and the phase composition is analyzed by X-ray diffraction (XRD). The material forms a continuous and protective alumina layer, the growth of the alumina layer following parabolic kinetics. Immediately below the scale Mo(Si,Al)₂ is replaced by a Mo₅(Si,Al)₃ layer due to the flux of aluminum to the scale. The Al concentration in the Mo(Si,Al)₂ phase in the underlying substrate decreases from 27% before exposure to 16–17% after 1000 h. The continuous alumina layer becomes covered by a top layer consisting of alumina grains embedded in a viscous melt with approximate composition 7 Na₂O–15 Al₂O₃–78 SiO₂. With time, sodium is volatilized from the melt and the top scale layer transforms to a mixture of alumina, mullite and silica melt.     

Solving House Allocation Problems with Risk-Averse Agents

This paper solves the fair and optimal house allocation problem (Sun and Yang, Econ Lett 81:73–79, 2003) when the agents preferences are represented by nonlinear utility functions using techniques for global mixed integer nonlinear optimization. A small simulation study indicates that if quasi-linear specifications are adopted as approximations to nonlinear utility functions and if the fair and optimal allocation is identified based on this approximation, then the prices are typically higher on average and the resulting allocation is typically non-fair.     

Affect-focused body psychotherapy in patients with generalized anxiety disorder: Evaluation of an integrative method.

The aim of this study was to explore the long-term effects of affect-focused body psychotherapy (ABP) for patients with generalized anxiety disorder (GAD). A group of 61 consecutive patients, 21–55 years old, were randomized to ABP and psychiatric treatment as usual (TAU). The patients were assessed before treatment and followed up 1 and 2 years after inclusion. The ABP patients received one session of treatment per week during 1 year. Three self-report questionnaires were administered; Symptom Checklist—90, Beck Anxiety Inventory, and the WHO (Ten) Well-Being Index. In both groups, there was a significant improvement. On termination, the ABP group had improved significantly more on the SCL-90 Global Symptom Index than the TAU group, whereas the differences were short of significance on the other two scales. The integration of bodily techniques with a focus on affects in a psychodynamically informed treatment seems to be a viable treatment alternative for patients with GAD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Social influence during the initial phase of a fire evacuation—Analysis of evacuation experiments in a cinema theatre

Unannounced evacuation experiments in a cinema theatre were analysed. The analysis focused on investigating if people are influenced by others during the initial phase of a fire evacuation. This type of influence is called social influence. Three separate behaviour types were identified and studied and the recognition and pre-movement time was measured. The results suggest that social influence is an important factor and that it becomes more important when the fire cue, e.g., the alarm, is unclear or uninformative. Results also indicate that social influence increases with decreasing distance between visitors. This result implies that individuals are influenced more by people who are close than by people who are further away.     

Key technologies for IMT-advanced mobile communication systems

WINNER is an ambitious research project aiming at identification, development, and assessment of key technologies for IMTAdvanced mobile communication systems. WINNER has devised an OFDMA-based system concept with excellent system-level performance for flexible deployments in a wide variety of operating conditions. The WINNER system provides a significant step forward from current 3G systems. Key innovations integrated into the system concept include flexible spectrum usage and relaying, adaptive advanced antenna schemes and pilot design, close to optimal link adaptation, hierarchical control signaling, and a highly flexible multiple access scheme. The end-to-end performance assessment results demonstrate that the WINNER concept meets the IMTAdvanced requirements.     

Wideband Low‐Reflection Transmission Lines for Bare Chip on Multilayer PCB

The pad pitch of modern radio frequency integrated circuits is in the order of few tens of micrometers. Connecting a large number of high‐speed I/Os to the outside world with good signal fidelity at low cost is an extremely challenging task. To cope with this requirement, we need reflection‐free transmission lines from an on‐chip pad to on‐board SMA connectors. Such a transmission line is very hard to design due to the difference in on‐chip and on‐board feature size and the requirement for extremely large bandwidth. In this paper, we propose the use of narrow tracks close to chip and wide tracks away from the chip. This narrow‐to‐wide transition in width results in impedance discontinuity. A step change in substrate thickness is utilized to cancel the effect of the width discontinuity, thus achieving a reflection‐free microstrip. To verify the concept, several microstrips were designed on multilayer FR4 PCB without any additional manufacturing steps. The TDR measurements reveal that the impedance variation is less than 3 Ω for a 50 Ω microstrip and S11 better than –9 dB for the frequency range 1 GHz to 6 GHz when the width changes from 165 µm to 940 µm, and substrate thickness changes from 100 µm to 500 µm.     

Does sodium fluoride in bone cement affect implant fixation? Part I: Bone tissue response, implant fixation and histology in nine rabbits

The addition of sodium fluoride to poly (methyl-methacrylate) (PMMA) bone cement may theoretically improve the fixation of joint replacement. This hypothesis was tested in an animal model using nine mature healthy lop-eared rabbits. A femoral prosthesis was inserted in both knees to resurface the patellofemoral articulation. The same acrylic cement, with and without sodium fluoride, was randomised between the two sides for prosthetic fixation. Two screw shaped implants machined from cured rods of either cement were also inserted bilaterally into the proximal tibia. Qualitative and quantitative histomorphometry of the bone tissue response surrounding the cement in the femur and the intact tibial implants revealed similar results regardless of sodium fluoride addition. Six weeks after surgery removal, torque did not significantly differ between the two sides. Our findings indicate that addition of sodium fluoride to PMMA has little effect on implant stability and bone remodeling in rabbits in the short-term.