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In this paper we explore students' pre-instruction knowledge of several conceptual and procedural pieces of knowledge that we believe are prerequisite to one's ability to generate correct light ray diagrams and understand image formation by a plane mirror. The research population is an algebra-based, introductory physics class of about 50 students at a medium-sized, urban, public university. Both individual interviews and written free response questions were used to gather data. © 2005 American Institute of Physics.

This project was initiated with an undergraduate student's exploration of two advanced research tools: the scanning electron microscope (SEM) and the atomic force microscope (AFM). A research project was developed to study the application of microscopy to introductory physics instruction, Nine modules covering various aspects of introductory physics were created. Module components included discussions, laboratory experiments and assessments. Four of the nine modules were implemented in various high school classes. Assessments were used to compare student learning with the modules versus standard textbook/lecture techniques, Preliminary results of this study are presented along with recently developed methods created to facilitate implementation of these modules within the high school classroom. © 2006 Materials Research Society.

Although oral motor therapy is sometimes used to treat articulation disorders in school-age children, several reports question its efficacy. In this case study, four first-grade students, two boys and two girls, received 15 half-hour sessions of oral motor treatment based on Easy Does it for Articulation: An Oral Motor Approach (). Pre- and post-test measures of the children's articulation indicated no real differences in speech production. These results question the efficacy of general and discrete oral motor exercises because they did not enhance the children's speech production. © 2005 Lippincott Williams & Wilkins.

We report flexible synthesis of group III-nitride nanowires and nanostructures by metalorganic chemical vapor deposition (MOCVD) via a catalytic vapor-liquid-solid (VLS) growth mechanism. Supersaturation and surface stoichiometry strongly influence the stability of liquid droplets and growth selectivity. To facilitate and sustain the VLS growth, indium catalyst is introduced based on thermodynamic consideration. The employment of mesoporous molecular sieves (MCM-41) helps to prevent the coalescence of catalyst droplets and to promote nucleation statistics. Both GaN and AlN nanowires have been synthesized using MOCVD. Three-dimensional AlNGaN trunk-branch nanostructures are reported to illustrate the versatility of incorporating the VLS mechanism into MOCVD process. © 2005 American Institute of Physics.

The interface formation mechanism during the molecular-beam epitaxy (MBE) of InAs/GaP has been studied with the aid of the In-Ga-P phase diagram. It is discovered that an initial dissolution and crystallization process similar to liquid phase epitaxy (LPE) may happen at sufficiently high temperature, resulting in a graded composition at the interface. Consequently, "parasitic LPE/MBE" is the name for this hybrid form of MBE. High-resolution TEM images confirm the existence of the interfacial layer in the sample grown at high temperature. The graded interface smears out the band offset and leads to a nonrectifying heterojunction. Low-temperature (LT) MBE growth can turn off the LPE component, enabling the growth of an abrupt interface. Based on this "LPE/MBE" model, a LT MBE technique is developed to grow an abrupt InAs/InGaP interface for heterojunction power Schottky rectifiers. The LT InAs/InGaP heterojunction demonstrates nearly ideal Schottky rectifier characteristics, while the sample grown at high temperature shows resistive ohmic characteristics. The LT InAs/InGaP Schottky diode also demonstrates good stability with respect to anneal temperature, similar to the InAs/GaP heterojunctions. © 2004 American Institute of Physics.

We report flexible synthesis of III-Nitride nanowires and heterostructures by metal-organic chemical vapor deposition (MOCVD) via a catalytic vapor-liquid-solid (VLS) growth mechanism. Indium is used as an in-situ catalyst to facilitate and sustain the stability of liquid phase droplet for VLS growth based on thermodynamic consideration. The employment of mesoporous molecular sieves (MCM-41) helps to prevent the coalescence of catalyst droplets and to promote nucleation statistics. Cathodoluminescence (CL) of GaN nanowires shows near band-edge emission at 370nm, and strong E 2 phonon peak is observed at room temperature in Raman scattering spectra. Both binary GaN and AlN nanowires have been synthesized by MOCVD. Three-dimensional AlN/GaN trunk-branch nanostructures are reported to illustrate the versatility of incorporating the VLS mechanism into MOCVD process. © 2005 Materials Research Society.

Recent elastic and inelastic neutron scattering studies of the highly frustrated pyrochlore antiferromagnet Tb2Ti2O7 have shown some very intriguing features that cannot be modeled by the local 〈111〉 classical Ising model, naively expected to describe this system at low temperatures. By including single-ion excitations from the ground state doublet to higher crystal field levels, we successfully describe the elastic neutron scattering pattern and dispersion relations in Tb2Ti2O7, quantitatively consistent with experimental observations. © 2003 The American Physical Society.

This paper reports the microstructure and physical properties of ferroelectric capacitors formed from SrBi2Ta2O9 (SBT) layers on Si with various buffer layers including jet-vapor deposited silicon nitride, zirconium oxide, hafnium oxide and thermally grown silicon oxide. Results from cross-sectional transmission electron microscopy (X-TEM), energy dispersive spectroscopy (EDS), X-Ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and non-contact atomic force microscopy (nc-AFM) data coupled with capacitance-voltage (C-V) and current-voltage (I-V) data indicate that both the microstructure and physical properties of SBT films deposited on silicon are dependent on the buffer layer material employed.

A new branched silicon nanostructure called Silicon Nano-Dendrite (SiND) was prepared by Laser ablation. During the Laser ablation process, the Argon flow was switched on and off very fast and simultaneously decreasing the flow rate, to create a non-steady-state flow. The resulting structure will open up new avenues in molecular electronics as the FeSi2 nano-particle at the end can be used to grow nanotube-nanowire junctions.

This article discusses the foresight of philosopher/mathematician Norbert Wiener who, in the 1940s, founded Information Ethics as a research discipline. Wiener envisioned the coming of an “automatic age” in which information technology would have profound social and ethical impacts upon the world. He predicted, for example, machines that will learn, reason and play games; “automatic factories” that will replace assembly-line workers and middle managers with computerized devices; workers who will perform their jobs over great distances with the aid of new communication technologies; and people who will gain remarkable powers by adding computerized “prostheses” to their bodies. To analyze the ethical implications of such developments, Wiener presented some principles of justice and employed a powerful practical method of ethical analysis. © 2004, Emerald Group Publishing Limited

The cluster of concerns usually identified as matters of privacy can be adequately accounted for by unpacking our natural rights to life, liberty, and property. Privacy as derived from fundamental natural rights to life, liberty, and property encompasses the advantages of the control and restricted access theories without their attendant difficulties., (C)2003 Kluwer Academic Publishers

This article discusses some "historical milestones" in computer ethics, as well as two alternative visions of the future of computer ethics. Topics include the impressive foundation for computer ethics laid down by Norbert Wiener in the 1940s and early 1950s; the pioneering efforts of Donn Parker, Joseph Weizenbaum and Walter Maner in the 1970s; Krystyna Gorniak's hypothesis that computer ethics will evolve into "global ethics"; and Deborah Johnson's speculation that computer ethics may someday "disappear"., (C)2001 Kluwer Academic Publishers

The focus of this article is primarily on the impact that the computer revolution has on college/university libraries, although many of the issues discussed here are relevant to other types of libraries as well. The university library in its present form is a product of the printing press revolution. In all likelihood, the computer revolution will have an even more profound impact on the library than did the printing press revolution.

The number of single-parent families has increased dramatically in the United States. The purpose of this study was to explore the types of family rituals present in single-parent families and their meaning within the family context. Little is known about family rituals in single-parent families, and therefore grounded theory was the qualitative research method used for this study. Unstructured face-to-face interviews were used to obtain data from a theoretical sample of seven single parents. Data analysis appropriate to the grounded theory method was utilized to identify a core variable and an emerging theory. Six types of rituals: connection, spiritual, love, recreation, celebration, and evolving were found to be used by these single-parent families as a way to facilitate family cohesion and instill family values. Applicability of the findings of this study are beneficial for nurses working with clients with diverse, changing, and complex social situations such as the single-parent family. © 2004 Sage Publications.

Dose-response experiments are crucial in biomedical studies. There are usually multiple objectives in such experiments and among the goals is the estimation of several percentiles on the dose-response curve. Here we present the first non-parametric adaptive design approach to estimate several percentiles simultaneously via generalized Pó lya urns. Theoretical properties of these designs are investigated and their performance is gaged by the locally compound optimal designs. As an example, we re-investigated a psychophysical experiment where one of the goals was to estimate the three quartiles. We show that these multiple-objective adaptive designs are more efficient than the original single-objective adaptive design targeting the median only. We also show that urn designs which target the optimal designs are slightly more efficient than those which target the desired percentiles directly. Guidelines are given as to when to use which type of design. Overall we are pleased with the efficiency results and hope compound adaptive designs proposed in this work or their variants may prove to be a viable non-parametric alternative in multiple-objective dose-response studies. Copyright © 2004 John Wiley & Sons, Ltd.