New materials for fireplace logs

Fibrous insulation and refractory concrete are used for logs as well as fireproof walls, incinerator bricks, planters, and roof shingles. Insulation is lighter and more shock resistant than fireclay. Lightweight slag bonded with refractory concrete serves as aggregrate

The Effects of Frequency of Usage on Pre-recognition Responses and Recognition Thresholds of Words

Tachistoscopic presentation of words has been widely used in the study of the relationship between personality variables and perception. The procedure is to present words drawn from relevant meaning classes, such as needs or values, for· increasing periods of exposure until the S is able to correctly identify the stimulus words. The results of several such experiments (3, 4, 8, 10) lend support to the view that personality factors are important determiners of an individual’s sensitivity to visually presented stimuli. However, since most of these studies have used verbal report as the index of perceptual sensitivity, many investigators have become increasingly concerned with the effects of verbal learning variables on recognition thresholds. Particular attention has recently been focused on the contribution of frequency of usage of words to variations in these recognition thresholds (5, 6, 7, 11, 12)

The Relationship Between Manifest Anxiety and Test Anxiety

Anxiety as an important determinant of behavior has been receiving increasing attention from both the clinician (5, 6, 15, 19, 23) and the experimental psychologist ( 2, 4, 8, 21) . Several measures of anxiety have been developed (6, 7, 9, 22) in order to study the relationship between anxiety as a personality variable and behavior in a variety of experimental situations. The purpose of this investigation was to study the interrelationships among three of the more widely used anxiety scales. Normative characteristics of the scales for the population sample will also be presented

The relative stability of cohabiting and marital unions for children

Children are increasingly born into cohabiting parent families, but we know little to date about the implications of this family pattern for children's lives. We examine whether children born into premarital cohabitation and first marriages experience similar rates of parental disruption, and whether marriage among cohabiting parents enhances union stability. These issues are important because past research has linked instability in family structure with lower levels of child well-being. Drawing on the 1995 National Survey of Family Growth, we find that white, black and Hispanic children born to cohabiting parents experience greater levels of instability than children born to married parents. Moreover, black and Hispanic children whose cohabiting parents marry do not experience the same levels of family stability as those born to married parents; among white children, however, the marriage of cohabiting parents raises levels of family stability to that experienced by children born in marriage. The findings from this paper contribute to the debate about the benefits of marriage for children.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43523/1/11113_2004_Article_5144453.pd

Critical Casimir effect in classical binary liquid mixtures

If a fluctuating medium is confined, the ensuing perturbation of its fluctuation spectrum generates Casimir-like effective forces acting on its confining surfaces. Near a continuous phase transition of such a medium the corresponding order parameter fluctuations occur on all length scales and therefore close to the critical point this effect acquires a universal character, i.e., to a large extent it is independent of the microscopic details of the actual system. Accordingly it can be calculated theoretically by studying suitable representative model systems. We report on the direct measurement of critical Casimir forces by total internal reflection microscopy (TIRM), with femto-Newton resolution. The corresponding potentials are determined for individual colloidal particles floating above a substrate under the action of the critical thermal noise in the solvent medium, constituted by a binary liquid mixture of water and 2,6-lutidine near its lower consolute point. Depending on the relative adsorption preferences of the colloid and substrate surfaces with respect to the two components of the binary liquid mixture, we observe that, upon approaching the critical point of the solvent, attractive or repulsive forces emerge and supersede those prevailing away from it. Based on the knowledge of the critical Casimir forces acting in film geometries within the Ising universality class and with equal or opposing boundary conditions, we provide the corresponding theoretical predictions for the sphere-planar wall geometry of the experiment. The experimental data for the effective potential can be interpreted consistently in terms of these predictions and a remarkable quantitative agreement is observed.Comment: 30 pages, 17 figure

Critical Casimir forces and adsorption profiles in the presence of a chemically structured substrate

Motivated by recent experiments with confined binary liquid mixtures near demixing, we study the universal critical properties of a system, which belongs to the Ising universality class, in the film geometry. We employ periodic boundary conditions in the two lateral directions and fixed boundary conditions on the two confining surfaces, such that one of them has a spatially homogeneous adsorption preference while the other one exhibits a laterally alternating adsorption preference, resembling locally a single chemical step. By means of Monte Carlo simulations of an improved Hamiltonian, so that the leading scaling corrections are suppressed, numerical integration, and finite-size scaling analysis we determine the critical Casimir force and its universal scaling function for various values of the aspect ratio of the film. In the limit of a vanishing aspect ratio the critical Casimir force of this system reduces to the mean value of the critical Casimir force for laterally homogeneous ++ and +- boundary conditions, corresponding to the surface spins on the two surfaces being fixed to equal and opposite values, respectively. We show that the universal scaling function of the critical Casimir force for small but finite aspect ratios displays a linear dependence on the aspect ratio which is solely due to the presence of the lateral inhomogeneity. We also analyze the order-parameter profiles at criticality and their universal scaling function which allows us to probe theoretical predictions and to compare with experimental data.Comment: revised version, section 5.2 expanded; 53 pages, 12 figures, iopart clas

Fertility, Living Arrangements, Care and Mobility

There are four main interconnecting themes around which the contributions in this book are based. This introductory chapter aims to establish the broad context for the chapters that follow by discussing each of the themes. It does so by setting these themes within the overarching demographic challenge of the twenty-first century – demographic ageing. Each chapter is introduced in the context of the specific theme to which it primarily relates and there is a summary of the data sets used by the contributors to illustrate the wide range of cross-sectional and longitudinal data analysed