Deep gamma ray penetration in thick shields

Appropriate importance function and sampling scheme facilitates the application of the Monte Carlo method to problems involving the deep penetration of radiation

Numerical study of weakly unstable electron plasma oscillations

Vlasov equation for solving initial value problem for unstable electron plasm

'Looking away': private writing techniques as a form of transformational text shaping in art & design and the natural sciences

Despite their long history and wide-spread use, the private writing techniques of journaling and freewriting remain largely underexploited in the field of academic writing instruction. They are seen only as forms of pre-writing, and are criticised by some for being under-theorised, vague and asocial. Contextualizing them within a writing-as-social-practice approach, and drawing on a conceptual framework including a notion of looking-away developed by Derrida, Vygotsky’s conception of learning development, and Ivanic’s notion of writer identity, this paper aims to throw new light on these private writing techniques and argues they can be transformational in developing students’ learning and identity, as well as written and non-written outputs. In this paper we theorise these practices through reflection on two instances of teaching in which they played an important part. The teaching interventions were in different disciplinary contexts (architectural design and Natural Sciences), with writers of different levels of expertise/competence (undergraduate and PhD), in both L1 and multilingual settings. In both interventions, we found that these private writing techniques were transformational due to the space they allowed writers to self-reflect, and to look away from their public-facing outputs. The techniques provided significant developmental benefits and moved the students along a continuum towards a more expert-like identity

Observations of protons in the magnetosphere with Mariner IV

Mariner IV low energy proton measurements of magnetospher

KIC 2856960: the impossible triple star

KIC 2856960 is a star in the Kepler field which was observed by Kepler for 4 years. It shows the primary and secondary eclipses of a close binary of 0.258d as well as complex dipping events that last for about 1.5d at a time and recur on a 204d period. The dips are thought to result when the close binary passes across the face of a third star. In this paper we present an attempt to model the dips. Despite the apparent simplicity of the system and strenuous efforts to find a solution, we find that we cannot match the dips with a triple star while satisfying Kepler's laws. The problem is that to match the dips the separation of the close binary has to be larger than possible relative to the outer orbit given the orbital periods. Quadruple star models can get round this problem but require the addition of a so-far undetected intermediate period of order 5 -- 20d that has be a near-perfect integer divisor of the outer 204d period. Although we have no good explanation for KIC 2856960, using the full set of Kepler data we are able to update several of its parameters. We also present a spectrum showing that KIC 2856960 is dominated by light from a K3- or K4-type star.Comment: 11 pages, 13 figures, accepted for publication in MNRAS August 21, 201

Combined State and Parameter Estimation for a Static Model of the Maypole (Hoop-Column) Antenna Suface

Parameter and state estimation techniques are discussed for an elliptic system arising in a developmental model for the antenna surface of the Maypole Hoop/Column antenna. A computational algorithm based on spline approximations for the state and elastic parameters is given and numerical results obtained using this algorithm are summarized

Completion Report: Arkansas State Pesticides in Ground Water Monitoring Project Phase V: Vulnerable areas in Jackson, Monroe, Lawrence and Lonoke Counties

In 1996, sixty-seven water samples were drawn from 65 wells, including 62 new wells and 3 wells sampled previously . One Woodruff County well and two Pulaski County wells were resampled. Thirty-two samples were drawn from 30 wells in Monroe County (well #1 was sampled 3 times during this phase) . Ten wells in Jackson County, 12 wells in Lawrence County and 10 wells in Lonoke were also tested (Figures 1-5) . With the completion of Phase V, the number of wells tested has risen to 231 with a total of 258 samples analyzed . Initially, the wells were tested for 13 pesticides and ni~rate. Two more pesticides, aldicarb and carbofuran were added to the analyte list during Phase V. The analyte list is shown in Table 3 . All results from all the wells are listed in Appendix A. Quality control information for these data follow the results. The Phase V Quality Assurance Report is included in this document as Part II

Particle acceleration due to shocks in the interplanetary field: High time resolution data and simulation results

Data were examined from two experiments aboard the Explorer 50 (IMP 8) spacecraft. The Johns Hopkins University/Applied Lab Charged Particle Measurement Experiment (CPME) provides 10.12 second resolution ion and electron count rates as well as 5.5 minute or longer averages of the same, with data sampled in the ecliptic plane. The high time resolution of the data allows for an explicit, point by point, merging of the magnetic field and particle data and thus a close examination of the pre- and post-shock conditions and particle fluxes associated with large angle oblique shocks in the interplanetary field. A computer simulation has been developed wherein sample particle trajectories, taken from observed fluxes, are allowed to interact with a planar shock either forward or backward in time. One event, the 1974 Day 312 shock, is examined in detail

Simultaneous observations of solar protons inside and outside the magnetosphere Progress report

Simultaneous observations of solar protons inside and outside magnetosphere by Explorer XXXIII AND Injun I