Floods in a changing climate: a review

This paper begins with an analysis of flooding as a natural disaster for which the solutions to the environmental, social and economic problems are essentially those of identifying and overcoming hazards and vulnerability, reducing risk and damaging consequences. Long-term solutions to flooding problems, especially in a changing climate, should be sought in the wider context of developing more sustainable social organization, economics and technology. Then, developments are described of how scientific understanding, supported by practical modelling, is leading to predictions of how human-induced changes to climatic and geological conditions are likely to influence flooding over at least the next 300 years, through their influences on evaporation, precipitation, run-off, wind storm and sea-level rise. Some of the outstanding scientific questions raised by these problems are highlighted, such as the statistical and deterministic prediction of extreme events, the understanding and modelling of mechanisms that operate on varying length- and time-scales, and the complex interactions between biological, ecological and physical problems. Some options for reducing the impact of flooding by new technology include both improved prediction and monitoring with computer models, and remote sensing, flexible and focused warning systems, and permanent and temporary flood-reduction systems.     

Determination of ZnO temperature coefficients using thin film bulk acoustic wave resonators

Thin film bulk acoustic wave (BAW) resonators have been the subject of research in RF microelectronics for some time. Much of the interest lay in utilizing the resonators to design filters for wireless applications. Some of the major advantages BAW devices present over other filter technologies in use today include size reduction and the possibility of on-chip integration. As the technology matures, the necessity to more fully characterize the performance of the devices and to develop more accurate models describing their behavior is apparent. In this investigation, the effects that temperature variations have on 1.8-2.0 GHz zinc oxide (ZnO)-based solidly mounted BAW resonators (SMRs) are studied. The average temperature coefficients of the series and parallel resonant frequencies of the fabricated devices are found to be -31.5 ppm//spl deg/C and -35.3 ppm//spl deg/C, respectively. The slight decrease in separation between the two resonant frequencies with temperature implies there is slightly less effective coupling with increased temperature. No definite trend is found describing the behavior of the quality factor (Q) of the resonator with temperature variations. With little temperature coefficient data for thin film ZnO available in the literature, the importance of an accurate model is evident. The resonator device performance is simulated using Ballato's electronic circuit model for acoustic devices on a SPICE-based platform. By virtue of the comparison between the predicted and measured device response, various material parameters are extracted.     

Preliminary study on human protein adsorption and leukocyte adhesion to starch-based biomaterials

In this study, the adsorption of human serum albumin (HSA), fibronectin (FN) and vitronectin (VN) onto the surface of novel biodegradable materials was evaluated by immunostaining. Specifically, polymeric blends of corn starch with cellulose acetate (SCA), ethylene vinyl alcohol copolymer (SEVA-C), and polycaprolactone (SPCL) were immersed in unitary and competitive systems; that is, binary and more complex protein solutions. For binary solutions, different HSA and FN protein distribution patterns were observed depending on the starch-based surface. Furthermore, the relative amount of proteins adsorbed onto starch-based surfaces was clearly affected by protein type: a preferential adsorption of VN and FN as compared to HSA was observed. On tests carried out with unitary, binary and more complex solutions, it was found that vitronectin adsorption ability was enhanced in competitive systems, which was associated with a lower amount of adsorbed albumin. In order to assess the effect of these human proteins on cell behavior, a mixed population of human lymphocytes and monocytes/macrophages was cultured over pre-coated SEVA-C surfaces. Through anti-CD3 and CD-14 monoclonal antibody labeling and cell counting, leukocyte adhesion onto pre-coated SEVA-C surfaces was analyzed. Based on the results, it was possible to detect albumin long-term effects and fibronectin short-term effects on cell adhesion proving that previously adsorbed proteins modulate leukocyte behavior.     

Ultrafine microsphere particles of zirconium titanate produced by homogeneous dielectric-tuning coprecipitation

Zirconium titanates are widely used in electrical (common microwave dielectrics) and optical devices as well as in bifunctional catalysis and structural ceramics. In this paper, ultrafine amorphous solid microsphere precursor particles of zirconium titanate (Zr _x Ti_{1 – x} O₂) with possibly tailored intraparticle nanostructure (i.e., nanosized pores) were synthesized by a dielectric-tuning solution coprecipitation method, in which inorganic salts were dissolved in a simple water-alcohol mixture and homogeneous nucleation and growth of particles were then induced by heating at temperatures below 100°C. Near-monodispersed particles were obtained. Particle sizes (nanometers to a few micrometers in diameter) were controlled by adjusting the process parameters such as salt concentration, alcohol-to-water volume ratio, temperature, and heating time. Nanosphere particles were produced with a rapid microwave heating nucleation-control scheme. Transmission electron microscopic analysis of each individual microsphere indicates that uniform nanostructures (a few nanometers in pore size) as well as compositional homogeneity (in terms of the Zr/Ti ratio) have been obtained inside each amorphous microsphere. In situhigh-temperature X-ray diffraction data show that no phase segregation was observed in as-preprared microspheres and the transition from amorphous to the single-crystalline ZrTiO₄phase occurred around 650°C for a composition of Zr/Ti = 1. Interestingly, thermal analysis (DTA/TGA) data indicate that the solution synthesis condition seems to affect the crystallization activation energy and onset temperature, which varies from 530 to 680°C.     

Computer modelling of the origin of defects in ceramic injection moulding

The acquisition of thermal property data for the subsequent computer modelling of solidification-induced defects in the injection moulding of ceramic suspensions is described. Thermal diffusivity of a polystyrene-zirconia suspension was measured between 80 and 160 °C. Volume thermal expansion and specific heat were also recorded as a function of temperature and the equation of state was derived. All the experiments use standard laboratory equipment making the procedure widely applicable. In subsequent work, these data will be used to predict the origin of voids and cracks in ceramic moulded bodies.     

Yield modeling of acoustic charge transport transversal filters

This paper presents a yield model for acoustic charge transport transversal filters. This model differs from previous IC yield models in that it does not assume that individual failures of the nondestructive sensing taps necessarily cause a device failure. A redundancy in the number of taps included in the design is explained. Poisson statistics are used to describe the tap failures, weighted over a uniform defect density distribution. A representative design example is presented. The minimum number of taps needed to realize the filter is calculated, and tap weights for various numbers of redundant taps are calculated. The critical area for device failure is calculated for each level of redundancy. Yield is predicted for a range of defect densities and redundancies. To verify the model, a Monte Carlo simulation is performed on an equivalent circuit model of the device. The results of the yield model are then compared to the Monte Carlo simulation. Better than 95% agreement was obtained for the Poisson model with redundant taps ranging from 30% to 150% over the minimum     

Directors of clinical training: An insider's perspective.

147 members of the Council of University Directors of Clinical Psychology Programs provided information about (1) their clinical programs, (2) personal demographic data, (3) their training and theoretical orientations, (4) various aspects of the position (e.g., personal satisfaction with and expectations for the job, reasons for taking the position, impact on career and personal life), (5) the relationship between the clinical program and the practicum component, and (6) the relationship of the clinical program to the psychology department. Results revealed a mixture of both positive and negative aspects, with most directors indicating satisfaction with the position despite considerable personal stress. Gender and age differences are discussed, as are limitations of the study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multiple cusps, duality and cardanic configurations in planar motion

Some little-known—perhaps unknown—instantaneous properties of line-envelopes are described, in every instance pointing out (through a combination of geometrical duality and kinematic inversion) how they relate to the better-known properties of point-paths. The emphasis is on singularities higher than simple cusps and inflexions, namely on double, triple, etc. cusps in envelopes, and on Ball's point and rhamphoid cusps in point-paths. Cardanic locations of a lamina are re-examined, and attention is drawn to the dual (inversional) behaviour at a Cardanic location. Mainly it is the familiar four-bar linkage which is used as the vehicle for demonstrating these properties and principles. Computer-graphics, using a number of recently-developed programmes, is seen to be of great help in elucidation and demonstration. Whilst the main message of the paper is in the domain of theory, nevertheless, in the setting of the 4-bar linkage as a mechanism-component, mention is made of the design-potential of computer-graphics. For instance, the possibility now exists of accurately presenting Ball's curve and what is here named the “double-cusp curve”. Both of these curves can be used in motion-synthesis.     

Early-treated phenylketonuria: adult neuropsychologic outcome

Twenty-five adults with phenylketonuria that was treated early were compared with 15 unaffected control siblings with respect to intellectual and neuropsychologic measures. Patients were found to have normal intelligence but were significantly lower than their control siblings on measures of intelligence, attention, and complex visuoconstructional ability. Stepwise multiple regression analyses found the patients' intellectual outcome to be best predicted by indexes reflecting early insult to the brain, whereas performance on a measure of novel problem solving was best predicted by concurrent serum phenylalanine level. Different pathophysiologic mechanisms may thus account for cognitive deficits in this population. These results provide further evidence of continuing benefits of dietary adherence into adulthood.