Enrichment exercises in spelling for grades two, three, and four

Thesis (Ed.M.)--Boston Universit

Lower James River pollution study, City Point to Chickahominy, August 6 - September 6, 1951 : a preliminary report of findings, conclusions and recommendations

Hopewell,m Virginia.is ·a highly industrialized city, the Celanese Corporation of .America, the Continental Can Company, the Hercules Powder Company and the Solvay Process: Division of· Allied Chemical and Dye Corporation having plants there. All of these plants have industrial and human wastes, the combined amount of which is great from. the standpoint of both volume and strength. In addition, there. are human wastes from the City cf Hopewell and its suburbs in Prince George County and from Camp Lee. All of those wastes, sewage and industrial are discharged into the James River, Bailey Creek and into other tributaries of the two. Primary treatment is given the wastes at Camp Lee; the others are discharged untreated. The location of all discharges in the Hopewell vicinity are shown in Figure I. With the exception of Bailey Creek, the impact of these wastes on the streams they enter was largely unknown, prior to this study. For many years Bailey Creek has been organized as an open sewer. Following passage of the Virginia. State Water Control -Law in 1946, the Hopewell industries all began programs leading to reduction of wastes they discharged. In order for them to determine the extent to which such reductions must ultimately be carried, it soon became apparent that information was needed regarding the effect of their wastes on the James River. During: the summer of 1951::the Hopowell industries, through the Hopewell Manufactures Association requested.the Water·Control Board\u27s help in making a study of the stream in the· Hopewell vicinity in an attempt to answer this question. The Board\u27s staff agreed to lend such assistance as was possible, and the initial phases of such a study were completed during the period ·August 6 - September 6, 1951

Creating Informal Play Opportunities: Are Parents\u27 and Preschoolers\u27 Initiations Related to Children\u27s Competence With Peers?

Preschoolers\u27 social competence may depend on the frequency with which informal play activities are initiated by parents\u27, children, and playmates. In this study, measures of children\u27s peer relations in informal and school contexts and the frequency of parents\u27, children\u27s, and peers\u27 play initiations were obtained with 83 preschool children and their families on 2 occasions. Frequent parent initiations were associated with higher levels of prosocial behavior, lower levels of nonsocial behavior and, among boys, greater peer acceptance in preschools. Children who were more initiating of informal peer contacts displayed less anxious behavior in school and were better liked by their classmates. Finally, the degree to which parents involved children in the process of arranging informal play activities was positively related to the frequency with which children initiated their own peer contacts

The Fuana of the State Quarry Beds

The State Quarry beds of Johnson County, Iowa, comprise a very local but decidedly interesting limestone formation of Upper Devonian age. In spite of its restricted distribution the formation has been the subject of some investigation, first because of the abundant fish remains found in certain beds, and secondly because other horizons furnished large blocks suitable for building purposes

Transport Phenomena and Structuring in Shear Flow of Suspensions near Solid Walls

In this paper we apply the lattice-Boltzmann method and an extension to particle suspensions as introduced by Ladd et al. to study transport phenomena and structuring effects of particles suspended in a fluid near sheared solid walls. We find that a particle free region arises near walls, which has a width depending on the shear rate and the particle concentration. The wall causes the formation of parallel particle layers at low concentrations, where the number of particles per layer decreases with increasing distance to the wall.Comment: 14 pages, 14 figure

A new model for simulating colloidal dynamics

We present a new hybrid lattice-Boltzmann and Langevin molecular dynamics scheme for simulating the dynamics of suspensions of spherical colloidal particles. The solvent is modeled on the level of the lattice-Boltzmann method while the molecular dynamics is done for the solute. The coupling between the two is implemented through a frictional force acting both on the solvent and on the solute, which depends on the relative velocity. A spherical colloidal particle is represented by interaction sites at its surface. We demonstrate that this scheme quantitatively reproduces the translational and rotational diffusion of a neutral spherical particle in a liquid and show preliminary results for a charged spherical particle. We argue that this method is especially advantageous in the case of charged colloids.Comment: For a movie click on the link below Fig

Educational Goods: Values, Evidence, and Decision-Making-A Summary

This is a brief summary of the book Educational Goods: Values, Evidence, and Decision‐Making by Harry Brighouse, Helen F. Ladd, Susanna Loeb and Adam Swift. It provides the introduction to the present symposium on this book, which includes the ensuing contributions from Carey Bagelman, Randall Curren, Michael Hand, John Tillson and Winston Thompson, followed by a response from the authors

Educational Goods Reconsidered: A Response

We gratefully reply to our five commentators, responding to their criticisms and comments under the following headings: parochialism and curriculum; rationality and truth; production and distribution; perfectionism, decision‐making and disagreement; adultism and parents' interests; non‐consequential educational goods; and self‐education

A lattice mesoscopic model of dynamically heterogeneous fluids

We introduce a mesoscopic three-dimensional Lattice Boltzmann Model which attempts to mimick the physical features associated with cage effects in dynamically heterogeneous fluids. To this purpose, we extend the standard Lattice Boltzmann dynamics with self-consistent constraints based on the non-local density of the surrounding fluid. The resulting dynamics exhibits typical features of dynamic heterogeneous fluids, such as non-Gaussian density distributions and long-time relaxation. Due to its intrinsically parallel dynamics, and absence of statistical noise, the method is expected to compute significantly faster than molecular dynamics, Monte Carlo and lattice glass models.Comment: 4 pages, 3 figures, to appear in Phys. Rev. Let