Transverse flow of nuclear matter in collisions of heavy nuclei at intermediate energies

The Quantum Molecular Dynamics Model (IQMD) is used to investigate the origin of the collective transverse velocity observed in heavy ion experiments. We find that there are three contributions to this effect: initial-final state correlations, potential interactions and collisions. For a given nuclear equation of state (eos) the increase of the transverse velocity with increasing beam energy is caused by the potential part. For a given beam energy the collective transverse velocity is independent of the nuclear eos but the relative contributions of potential and collisions differ. In view of the importance of the potential interactions between the nucleons it is not evident that the similarity of the radial velocities measured for fragments at beam energies below 1 AGeV and that for mesons at beam energies above 2 AGeV is more than accidental.Comment: 5 pages, 5 figures, revtex, OASIS ref PLB1700

Nuclear Flow in Consistent Boltzmann Algorithm Models

We investigate the stochastic Direct Simulation Monte Carlo method (DSMC) for numerically solving the collision-term in heavy-ion transport theories of the Boltzmann-Uehling-Uhlenbeck (BUU) type. The first major modification we consider is changes in the collision rates due to excluded volume and shadowing/screening effects (Enskog theory). The second effect studied by us is the inclusion of an additional advection term. These modifications ensure a non-vanishing second virial and change the equation of state for the scattering process from that of an ideal gas to that of a hard-sphere gas. We analyse the effect of these modifications on the calculated value of directed nuclear collective flow in heavy ion collisions, and find that the flow slightly increases.Comment: 12 pages, REVTeX, figures available in PostScript from the authors upon reques

ANALYSIS OF ENERGY SAVINGS THROUGH THE USE OF DISPLACEMENT VENTILATION IN DOMESTIC BUILDINGS

This study investigates the conditions under which it might be possible to implement a displacement ventilation system in a residential building. An experimental study of the impact on a mechanical air conditioning system of the vertical location of the inlet and outlet vents was performed. The four ventilation configurations of low inlet high outlet, low inlet low outlet, high inlet high outlet, and high inlet low outlet were compared. These four configurations were compared under 13 different heat load scenarios in a full scale instrumented model room. It was found that, for higher heat loads, the low inlet high outlet configuration was able to maintain approximately the same temperature in the occupied region as for a lower heat load, while developing a strong two layer stratification within the room such that the outlet temperature was significantly higher than the ambient temperature in the lower occupied region of the room. This was achieved because this ventilation configuration was able to stratify the temperature within the room and force the heat into the upper unoccupied region. From this zone the outlet was able to more efficiently remove the unwanted heat. The increased outlet temperature means that the inlet temperature can be closer to the temperature required for thermal comfort meaning that less pre-cooling of air is required. The results show that, even with only a 2.5 meter ceiling height, comparable to most residential applications, the displacement ventilation configuration was able to reduce the need for mechanical conditioning. This would have a noticeable impact on the energy requirements of a residential building

A Phenomenological Study Of Teachers’ Motivations To Use Instructional Technology

The purpose of this qualitative transcendental phenomenological study was to identify and describe the factors that motivate teachers to integrate instructional technology in a district that has a 1:1 Chromebook program and tech-rich classroom environments. The research questions guiding this study were: How do middle school teachers describe the impact of access to contemporary technology resources on their motivation to integrate technology in their classrooms?; What are middle school teachers’ perceptions of how professional development experiences impact their motivation to integrate technology in the classroom?; How do the lived experiences of middle school teachers impact how they integrate technology in their classrooms? The theories guiding this study were the technology acceptance model (Davis, 1989) as is focused on user acceptance or rejection of new technologies, and the self-determination theory (Deci and Ryan, 1985). The sample consisted of ten participants who are employed in a school district that utilizes a 1:1 Chromebook program and has access to various technologies within the classroom space. Data were collected via interviews, observations, and writing prompts. The data were analyzed in accordance with Moustakas’s (1994) analysis procedures. Findings from this study revealed the factors that teachers found were most influential on their utilization of instructional technology. The researched revealed the importance of high self-efficacy that results from the necessary support from district and school leadership, access to resources, and clear intentions for student achievement and success on teachers’ motivation to integrate technology in their classroom practices

Isospin effects on the energy of vanishing flow in heavy-ion collisions

Using the isospin-dependent quantum molecular dynamics model we study the isospin effects on the disappearance of flow for the reactions of $^{58}Ni$ + $^{58}Ni$ and $^{58}Fe$ +$^{58}Fe$ as a function of impact parameter. We found good agreement between our calculations and experimentally measured energy of vanishing flow at all colliding geometries. Our calculations reproduce the experimental data within 5%(10%) at central (peripheral) geometries

Influence of momentum-dependent interactions on balance energy and mass dependence

We aim to study the role of momentum-dependent interactions in transverse flow as well as in its disappearance. For the present study, central collisions involving mass between 24 and 394 are considered. We find that momentum-dependent interactions have different impact in lighter colliding nuclei compared to heavier colliding nuclei. In lighter nuclei, the contribution of mean field towards the flow is smaller compared to heavier nuclei where binary nucleon-nucleon collisions dominate the scene. The inclusion of momentum-dependent interactions also explains the energy of vanishing flow in $^{12}C+^{12}C$ reaction which was not possible with the static equation of state. An excellent agreement of our theoretical attempt is found for balance energy with experimental data throughout the periodic table

An application of Fleck effective scattering to the difference formulation for photon transport

We introduce a new treatment of the difference formulation[1] for photon radiation transport without scattering in 1d slab geometry that is closely analogous to that of Fleck and Cummings[2] for the traditional formulation. The resulting form is free of implicit source terms and has the familiar effective scattering of the field of transport

Care provision for people with Fragile X Syndrome: Should it be need or diagnosis driven?

Initially, researchers proposed that Fragile X syndrome (FXS) should be called AFRAX syndrome because it was thought to be caused by an autism gene (Gillberg, Persson, & Wahlström, 1986). However, as research into FXS has progressed and an exploration of the behavioural phenotype has taken place important differences have emerged. The systematic review (Paper 1) aims to delineate a behavioural phenotype for Fragile X Syndrome (FXS). Ten papers were included in the review. All papers were of a standard to demonstrate a behavioural phenotype for FXS. There are attributes of the FXS behavioural phenotype that meet the criteria for both Attention Deficit Hyperactive Disorder (ADHD) and/or Autism Spectrum Condition (ASC). However, there is robust evidence to support a broad FXS behavioural phenotype comprising: 1) social behavioural and communication difficulties, 2) emotional regulation difficulties, 3) repetitive and restrictive behaviour and speech. Several recommendations for research and clinical practice are discussed. The aim of the empirical study (paper 2) was to examine if there are differences between the behaviour phenotype profiles of those with FXS who have a diagnosis of ASC and those that do not. Parents were asked to complete an online questionnaire that included the Social Responsiveness Scale (SRS), the Wessex Questionnaire, and standard demographic information. The findings of the 38 parents who completed the questionnaire are discussed below. Finally, the research review (Paper3) will explore the author’s research process. This includes a discussion about the decisions to undertake the research, as well as a review of the methodological limitations, implications for policy direction, further research and clinical implications