Pulsed underwater corona discharges as a source of strong oxidants: *OH and H2O2.

Because of undesirable side effects of chemical methods pulsed underwater corona discharges are emerging as a potential future advanced oxidation process (AOP) for water disinfection. In pulsed corona discharges a discharge channel is created, which contains a non-thermal plasma with a low degree of ionisation and low electron densities, but with electron energies of up to 10 eV. It has been demonstrated that electrons with this energy can dissociate water and oxygen molecules and produce various reactive radicals (*OH, H*, O*, HO2*), molecular species (H2O2, H2, O2), ultraviolet radiation and shock waves. It is supposed that the combination of all effects leads to a very efficient killing of microorganisms. To understand this in detail and to improve the efficiency of the overall system there is the need to develop suitable diagnostic methods for the quantitative determination of the various oxidants produced during the discharge. In this paper we present preliminary experimental results obtained with different chemical probes for *OH radicals, and H2O2 produced by pulsed corona discharges.     

Updated Characteristics of Torrential Pools

Power Technology and Engineering - Advanced methods for determining the hydrological and geomorphological characteristics of torrential pools, which are important for the design of reliable and...     

Projecting the future size and health status of the U.S. elderly population

"A projection model based on a multivariate continuous state, stochastic process is presented. The model allows multiple time-varying covariates to be used so parameters can be estimated from time series information on health changes and mortality, and their interaction. Health changes are simulated by altering parameters controlling the age trajectory and diffusion of risk factor means, variances, and covariances....By increasing the information used in projections it may be possible to better (a) anticipate the state of health at extreme ages, (b) forecast changes in health at specific ages over time, (c) stimulate the effects of specific interventions, and (d) determine the sensitivity of outcomes to a range of interventions."     

MIGRATION FROM THE NORTHEAST TO THE SOUTHEAST IN BRAZIL:* Do Migrants Succeed?

"In this paper 1980 [Brazilian] Census microdata are used to evaluate the experiences of males who moved from the Northeast to the Southeast in the post- 'miracle' period. Using regression analysis, migrant earnings are compared to those of persons who remain in the Northeast, to estimate the average earnings gain from relocating. These results are then disaggregated by education, age at migration, period of residence, and particular sending and receiving location, to provide more specific information on which groups benefit most. Wide variation in gains is observed, but substantial improvements in earnings are reported in most cases."     

Timing and duration effects in residence histories and other longitudinal data: II. Studies of duration effects in Norway, 1965-1971

The main results of eleven studies of the nature and determinants of the timing of moves and duration of residence effects are presented. The studies (see table 1) illustrate the use of the methodological framework for studying individual histories of the previous article. There are substantial duration of residence effects in most population subgroups, implying that the migration process in non-Markovian at the mocro level and that the semi-Markov model is required. However, characterization of effects and their determinants are shown to depend so heavily on the type of interval and observation scheme used, that only within a comprehensive framework is proper interpretation of empirical results possible.     

The Self-concept of Black and White Women: The Influences Upon Its Formation of Welfare Dependency, Work Effort, Family Networks, and Illnesses

Abstract . The concept of “self-efficacy” is used to test the hypothesis that the negative self-concept of welfare recipients coniributes to long term psychological and material dependency on such assistance. Self-efficacy focuses on the extent to which people are able to produce and regulate events in their lives and is associated with self-imposed performance expectations. The extent to which the minority status which Blacks occupy in this society decreases self efficacy relative to Whites is examined, using information generated from structured interviews with 290 low income Black and White women. Operationalizing the concept of self-efficacy with appropriate controls for socioeconomic status, family composition and other factors results in finding no racial differences in sense of self-efficacy between Black and White women. Observed differences in patterns of receipt of public assistance are found to be more directly related to the persistence of structural barriers to upward mobility that have differential impacts on Blacks and Whites. Long term receipt of public assistance is found to adversely affect both self-worth and work orientation/perceived efficacy for all women.     

Cost and technical change: Effects from bank deregulation

Banks were substantially deregulated during the 1980s. This altered the cost-minimizing mix between deposit interest payments and operating expenses (capital and labor for branch convenience and free deposit services). Measured bank output was relatively unaffected by these changes. The proportion of deposits receiving higher interest rates increased more rapidly than factor quantities were reduced, so unit deposit costs rose. Consumers benefited, but the measured net effects for banks were negative, averaging –0.8% to –1.4% a year in net technical change from 1977 to 1988. These influences were measured three different ways and for both equilibrium and disequilibrium factor input specifications. All three approaches—a standard time trend, a time-specific index, and shifts in cross-sectional cost functions—gave consistent results. The results were robust whether measured at the banking firm or branch office level or on the cost frontier.