Naturally Occurring Radioactive Materials in Produced Water and Oil-Field Equipment

This report summarizes the current knowledge of naturally occurring radioactive materials in oil-fields of the United States. Of particular concern is the effect on public health and the environment of exposure to radioactive materials in the form of radium-bearing water and 'scale' deposits in tanks and pipes, which may travel far from the oil fields as scrap metal products. Educational levels: Graduate or professional

Phase Separation and the Dual Nature of the Electronic Structure in Cuprates

The dual nature of the electronic structure of stripes in $La_{2-x}Sr_xCuO_4$ was characterized by experimental observations, mainly by ARPES, of nodal spectral weight together with the straight segments near antinodal regions. We present here an attempt to understand this dual behavior in terms of the competition of order and disorder, by applying the phase separation theory of Cahn-Hilliard (CH) to the high pseudogap temperature, which is very large in the far underdoping region and vanishs near the doping level p=0.2. The spinodal phase separation predictions together with the Bogoliubov-deGennes (BdG) superconducting theory provides several interesting insights. For instance, we find that the disorder enhances the local superconducting gap which scales with the leading edge shift and that, upon doping, the size of the hole-rich stripes increases, yielding to the system their metallic properties.Comment: revised version, 4 pages and 3 fig

Numerical Study of the Cahn-Hilliard Equation in One, Two and Three Dimensions

The Cahn-Hilliard equation is related with a number of interesting physical phenomena like the spinodal decomposition, phase separation and phase ordering dynamics. On the other hand this equation is very stiff an the difficulty to solve it numerically increases with the dimensionality and therefore, there are several published numerical studies in one dimension (1D), dealing with different approaches, and much fewer in two dimensions (2D). In three dimensions (3D) there are very few publications, usually concentrate in some specific result without the details of the used numerical scheme. We present here a stable and fast conservative finite difference scheme to solve the Cahn-Hilliard with two improvements: a splitting potential into a implicit and explicit in time part and a the use of free boundary conditions. We show that gradient stability is achieved in one, two and three dimensions with large time marching steps than normal methods.Comment: 20 pages with 12 figs. Accepted in the Physica

SECONDARY ELA TEACHERS’ PERCEPTIONS OF CLASSROOM DYNAMICS IN A TECHNOLOGY-RICH LEARNING ENVIRONMENT

The purpose of this narrative study was to explore secondary ELA teachers’ perceptions of teaching and learning in a technology-rich educational environment. This study was conducted in a central high school district in New York state across four school buildings. Though the central high school district provides uniform guidance and material for the instructional programs in all high school buildings, the execution of instruction and teacher development happens daily in the buildings themselves. Though one district, each building serves distinct communities with pronounced school cultures stemming from varying student and faculty demographics, as well as building leadership. The researcher explored the lived experiences of teachers in these different settings through narrative inquiry methods. The researcher interviewed eight participants through three rounds of semi-structured interviews. In this study, which explored teacher perceptions of the use of educational technology and their relationship to the profession because of the incorporation of educational technology in their secondary ELA classrooms, the researcher found that intentional planning at the district, building, and individual level improves quality of instruction. Though this finding may seem self-evident, the experience of teachers suggests that it is not necessarily practiced when incorporating digital technology into classroom instruction. The researcher suggests that districts take a subtractive approach to implementing digital technology, so teachers can plan and execute intentional lessons that make the strongest use of all instructional tools

Comprehensive genetic assessment of the ESR1 locus identifies a risk region for endometrial cancer

Excessive exposure to estrogen is a well-established risk factor for endometrial cancer (EC), particularly for cancers of endometrioid histology. The physiological function of estrogen is primarily mediated by estrogen receptor alpha, encoded by ESR1. Consequently, several studies have investigated whether variation at the ESR1 locus is associated with risk of EC, with conflicting results. We performed comprehensive fine-mapping analyses of 3633 genotyped and imputed single nucleotide polymorphisms (SNPs) in 6607 EC cases and 37 925 controls. There was evidence of an EC risk signal located at a potential alternative promoter of the ESR1 gene (lead SNP rs79575945, P=1.86x10(-5)), which was stronger for cancers of endometrioid subtype (P=3.76x10(-6)). Bioinformatic analysis suggests that this risk signal is in a functionally important region targeting ESR1, and eQTL analysis found that rs79575945 was associated with expression of SYNE1, a neighbouring gene. In summary, we have identified a single EC risk signal located at ESR1, at study-wide significance. Given SNPs located at this locus have been associated with risk for breast cancer, also a hormonally driven cancer, this study adds weight to the rationale for performing informed candidate fine-scale genetic studies across cancer types