A Note on Normalised Distributions of DC Partial Microdischarges

Statistical distributions (exponential and Pareto) of DC partial microdischarges running within sandwich electrode systems are discussed from the viewpoint of a normalisation procedure which may influence some features of the final distribution

Non-linear Temperature Profiles

Non-linear temperature profiles caused by temperature-dependent thermal conductivity l(T) of wall materials are discussed. Instead of conventional thermal resistance, modified effective resistance has been introduced

Fractality of Electrostatic Microdischarges on the Surface of Polymers

Ramified Lichtenberg figures caused by electrostatic microdischarges on the surface of polymeric polyethylene terephthalate have been studied. They occurred in consequence of the previous electret forming of the polymeric sheets and were initiated in the air gap between the grounded electrode and the polymeric sheets. Multifractal image analysis was used to determine the fractal dimensions of the Lichtenberg patterns in dependence on the loading voltages used for electret forming

Stocking strategies for a pre-alpine whitefish population under temperature stress

Cold-water fish stocks are increasingly affected by steadily increasing water temperatures. The question arises whether stock management can be adapted to mitigate the consequences of this climatic change. Here, we estimate the effects of increasing water temperatures on fisheries yield and population dynamics of whitefish, a typical cold-water fish species. Using a process-based population model calibrated on an empirical long-term data set for the whitefish population (Coregons lavaretus (L.) species complex) of the pre-alpine Lake Irrsee, Austria, we project density-dependent and temperature-dependent population growth and compare established stock enhancement strategies to alternative stocking strategies under the aspect of increasing water temperatures and cost neutrality. Additionally, we contrast the results obtained from the process-based model to the results from simple regression models and argue that the latter show qualitative inadequacies in projecting catch with rising temperatures. Our results indicate that increasing water temperatures reduce population biomass between 2.6% and 7.9% and catch by the fishery between 24% and 48%, depending on temperature scenario and natural mortality calculation. These reductions are caused by accelerated growth, smaller asymptotic size and lower annual survival of whitefish. Regarding stocking strategies under constant temperatures, we find that stocking mostly whitefish larvae, produces higher population biomass than stocking mostly one-summer-old whitefish, while catch remains almost constant. With increasing temperatures, stocking one-summer-old fish is more beneficial for the angling fishery. Adaption to climate change by changing stocking strategies cannot, however, prevent an overall reduction in catch and population size of this cold-water fish species

Correlated two-particle scattering on finite cavities

The correlated two-particle problem is solved analytically in the presence of a finite cavity. The method is demonstrated here in terms of exactly solvable models for both the cavity as well as the two-particle correlation where the two-particle potential is chosen in separable form. The two-particle phase shift is calculated and compared to the single-particle one. The two-particle bound state behavior is discussed and the influence of the cavity on the binding properties is calculated.Comment: Derivation shortened and corrected, 14 pages 10 figure

Using Motivational Interviewing in Public Health Practice to Prevent Fetal Alcohol Syndrome

Background: Surveys of women in prenatal care at busy clinics in Detroit, Michigan have reported 12.5% continue to drink during pregnancy (Flynn et al, 2003) and women in substance abuse treatment programs in Wayne County, MI have an incidence rate for Fetal Alcohol Syndrome (FAS) of 4 in 1,000 births, double the national prevalence rate of FAS. The goal of the current study was to intervene with women at high risk for an alcohol-exposed pregnancy using techniques of Brief Motivational Interviewing (BMI) in a verbal and written format. Methods: One third (33%) of 1,784 women screened at Detroit Department of Health and Wellness Promotion (DHWP) primary health care clinics and HIV/AIDS-STD clinic were found to be at risk of an alcohol exposed pregnancy defined as binge drinking (at least 4 drinks per occasion) or heavy drinking (8 or more drinks per week) in the last three months, while they were having sex with inconsistent or no contraception. This intervention utilized Brief Motivational Interviewing (BMI) and developed written materials based on the principles of BMI to 1) assess readiness for change, 2) strengthen motivation to change, and 3) provide an individualized change plan. For women who received the Individual Level Intervention (n = 77), four sessions of BMI were conducted (two in-person, two via telephone) over a six-month period. A Self-Guided Change version of the intervention (Community Level Intervention) was offered for women (n = 327) who preferred to utilize the materials at home and receive two follow-up telephone calls following baseline interview, also during a six-month period. Results: Both strategies, based on principles of Motivational Interviewing, have been shown to be effective in reducing drinking and increasing contraceptive use. Out of the 404 women participating in the program, 310 (77%) women completed at least one follow-up and were included in the analyses. Overall, 59.9% of the women enrolled in both interventions were no longer at risk for an alcohol-exposed pregnancy at the end of the intervention six months later. Conclusion: Brief Motivational Interviewing, delivered verbally or in a written format, is an effective method of reducing women’s risky behaviors for an alcohol exposed pregnancy. The Individual Level Intervention that included 2 face-to-face sessions resulted in less attrition than the Self-Guided Change version which relied on phone and mail contact only

Current Research into Applications of Tomography for Fusion Diagnostics

Retrieving spatial distribution of plasma emissivity from line integrated measurements on tokamaks presents a challenging task due to ill-posedness of the tomography problem and limited number of the lines of sight. Modern methods of plasma tomography therefore implement a-priori information as well as constraints, in particular some form of penalisation of complexity. In this contribution, the current tomography methods under development (Tikhonov regularisation, Bayesian methods and neural networks) are briefly explained taking into account their potential for integration into the fusion reactor diagnostics. In particular, current development of the Minimum Fisher Regularisation method is exemplified with respect to real-time reconstruction capability, combination with spectral unfolding and other prospective tasks.EURATOM 63305

A transfer matrix method for the analysis of fractal quantum potentials

The scattering properties of quantum particles on fractal potentials at different stages of fractal growth are obtained by means of the transfer matrix method. This approach can be easily adopted for project assignments in introductory quantum mechanics for undergraduates. The reflection coefficients for both the fractal potential and the finite periodic potential are calculated and compared. It is shown that the reflection coefficient for the fractal has a self-similar structure associated with the fractal distribution of the potential

Freshwater Ecosystems: From Models to Applications

Freshwater ecosystems—lakes and streams—are being endangered by agricultural, urban, and industrial pollution; hydraulic engineering; and overexploitation, which threaten their capacity to provide important services (recreation and supply of food and clean water, among others). Ecological modeling may be employed to estimate impacts and analyze mitigation strategies. Toy models are easy to construct, but applying them to real-world problems is often challenging. Here, we show in two case studies how the connection from model to application can be made. The first study analyzes whether and how the impact of climatic change on a mostly recreational fishery in an Alpine lake can be mitigated, while the second looks at restoring biodiversity after cleaning up pollution in a Korean river system, using aquatic insects, which play an essential functional role in aquatic food-webs and are very sensitive to water quality, as indicators of ecosystem health. These studies highlight the ability of process-based eco-evolutionary models to generate testable hypotheses and contribute solutions to real-world problems