Determination of Lithium Isotope Concentration by Laser Induced Breakdown Spectroscopy Using Chemometrics

The role of enriched 6Li in nuclear applications makes the ability to detect and monitor lithium enrichment activity imperative. Detecting levels of enrichment of this isotope currently requires sensitive, complex equipment operated by highly-trained technicians, which is prohibitive to rapid detection of enrichment activity. While commercial companies market portable laser induced breakdown spectroscopy (LIBS) with the ability to detect elements on the order or parts per million concentrations, they have not yet been demonstrated to possess the ability to quantitatively determine isotopic concentrations of lithium. This research performs single-pulse LIBS experiments under laboratory conditions to determine concentrations of 7Li and 6Li in solid samples of lithium hydroxide monohydrate in low-pressure argon environments. Spectra containing the atomic emission of lithium near 670.8 nm are collected in LIBS experiments. Chemometric analysis techniques (principal components regression, partial least squares regression, and neural networks analysis) are applied to these collected spectra to develop calibration curves for this equipment. This analysis suggests that bulk lithium isotopic assay can be determined via LIBS in situ to within a 95% confidence interval in as little as ten minutes for enrichment levels from 3 to 75%. Evidence of plasma self-absorption in isotopic emission spectra is also measured for the first time. Separately, observation of molecular emissions from LiH and LiO was attempted

UNDERSTANDING CLASSROOM ENGAGEMENT FOR MIDDLE SCHOOL STUDENTS

The purpose of this study is to understand the dynamics of student engagement and motivation in middle school students. The action research method involves collecting quantitative data through a student survey first and then explaining the quantitative results with in-depth qualitative data through interviews and focus groups. In the first, quantitative phase of the study, the motivation and engagement scale data will be collected from middle school students in the fifth through eighth grade of Regents School of Oxford to test the motivation and engagement of these students to assess whether intrinsic motivations relate to classroom student engagement. The second qualitative phase will be conducted as a follow-up to the quantitative results to help explain the reasons for motivation and engagement. In this exploratory follow-up the tentative plan is to explore student engagement through focus groups with middle school students who participated in the Motivation and Engagement Survey Profile. These focus groups will provide clarity around the reasons why students tend to lose motivational excitement about school and begin to show behavioral disengagement from class

An agent-based simulation of wheat based ethanol plant location decisions for Saskatchewan

First generation ethanol production has experienced rapid expansion but is now at a crossroads facing impending industry transformation. While Saskatchewan’s ethanol industry has benefited from demand and policy instruments that have guided substantial growth in recent years, changing policy and market dynamics present new challenges which are compelling the industry to adjust. This thesis examines three factors that are suspected to influence ethanol plant locational decisions. The development of an agent-based simulation model in this thesis will ascertain how transportation networks, market synergies, and subsidization influence location stability for an ethanol plant. The long term interaction of these factors is unknown, therefore do tradeoffs exist between these factors or is it conditional for all to be present? Modeling factors that affect location stability through an agent-based approach creates a dynamic framework to understand how location attributes impact an ethanol agent’s longevity. It was found that location stability is affected by an ethanol agent’s distance to both primary transportation networks as well as product markets. Surprisingly, distance to DDGS (dried distillers grain with solubles) markets, a low value by-product of ethanol production, has a profound effect on location stability. Policy instruments and industry subsidization are considered key ethanol development drivers and the surge in ethanol industry growth brought hopes of rural revitalization. In Saskatchewan, policy was developed to support small ethanol plants, those 25 Mmly (million litres per year) or smaller, aimed at increasing farmer investment and alternative markets for wheat. Measuring the effect of subsidization on location stability was fundamental to understanding how a post subsidized ethanol industry may look. The research found that subsidization of Saskatchewan’s ethanol industry dramatically affected economies of scale and location decisions, which left ethanol agents unable to compete in an increasingly competitive ethanol industry

Association between reduced stillbirth rates in England and regional uptake of accreditation training in customised fetal growth assessment

Objective: To assess the effect that accreditation training in fetal growth surveillance and evidence-based protocols had on stillbirth rates in England and Wales. Design: Analysis of mortality data from Office of National Statistics. Setting: England and Wales, including three National Health Service (NHS) regions (West Midlands, North East and Yorkshire and the Humber) which between 2008 and 2011 implemented training programmes in customised fetal growth assessment. Population: Live births and stillbirths in England and Wales between 2007 and 2012. Main: outcome measure Stillbirth. Results: There was a significant downward trend (p=0.03) in stillbirth rates between 2007 and 2012 in England to 4.81/1000, the lowest rate recorded since adoption of the current stillbirth definition in 1992. This drop was due to downward trends in each of the three English regions with high uptake of accreditation training, and led in turn to the lowest stillbirth rates on record in each of these regions. In contrast, there was no significant change in stillbirth rates in the remaining English regions and Wales, where uptake of training had been low. The three regions responsible for the record drop in national stillbirth rates made up less than a quarter (24.7%) of all births in England. The fall in stillbirth rate was most pronounced in the West Midlands, which had the most intensive training programme, from the preceding average baseline of 5.73/1000 in 2000–2007 to 4.47/1000 in 2012, a 22% drop which is equivalent to 92 fewer deaths a year. Extrapolated to the whole of the UK, this would amount to over 1000 fewer stillbirths each year. Conclusions: A training and accreditation programme in customised fetal growth assessment with evidence-based protocols was associated with a reduction in stillbirths in high-uptake areas and resulted in a national drop in stillbirth rates to their lowest level in 20 years

Pouzay – Les Cholettes

Date de l'opération : 1987 - 1989 (PR) Inventeur(s) : Wood Jason Dans le cadre d'un programme pluriannuel pour le site "les Cholettes" sur la commune de Pouzay, la Direction des Antiquités Historiques de la région Centre, une équipe anglaise de l'Université de Lancaster et le Laboratoire des Civilisations de l'Antiquité de l'Université de Tours ont mené des prospections de surface et géophysiques sur la partie monumentale de l'établissement gallo-romain, déjà exploré en 1982 par prospection é..

Vernou-sur-Brenne – Le Palais de Pépin-le-Bref

Date de l'opération : 1990 (FP) ; 1989 (SD) Inventeur(s) : Wood Jason Les vestiges, encore très bien conservés de l'édifice connu dans la région sous le nom de « Palais de Pépin le Bref » n'ayant jamais fait l'objet d'études sérieuses, un programme de recherches fut mis sur pied pour permettre la réalisation d'une étude topographique et architecturale en 1988 et de fouilles de sondages en 1989. Dans un premier temps, il fut donc établi un plan précis du site (Fig. n°1 : Palais, plan général)..

Evolution of proton-induced defects in a cryogenically irradiated p-channel CCD

P-channel CCDs have been shown to display improved tolerance to radiation-induced charge transfer inefficiency (CTI) when compared to n-channel CCDs. This is attributed to the properties of the dominant charge-trapping defect species in p-channel silicon relative to the operating conditions of the CCD. However, precise knowledge of defect parameters is required in order to correct for any induced CTI. The method of single trap-pumping allows us to analyse the defect parameters to a degree of accuracy that cannot be achieved with other common defect analysis techniques such as deep-level transient spectroscopy (DLTS). We have analysed using this method the defect distribution in an e2v p-channel CCD204 irradiated with protons at cryogenic temperature (153K). The dominant charge trapping defects at these conditions have been identified as the donor level of the silicon divacancy and the carbon interstitial defect. The defect parameters are analysed both immediately post irradiation and following several subsequent room-temperature anneal phases. The evolution of the defect distribution over time and through each anneal phase provides insight into defect interactions and mobility post-irradiation. The results demonstrate the importance of cryogenic irradiation and annealing studies, with large variations seen in the defect distribution when compared to a device irradiated at room-temperature, which is the current standard procedure for radiation testing

Larçay – La Tour, castellum du Bas-Empire

Date de l'opération : 1985 - 1987 (FP) Inventeur(s) : Wood Jason Après des sondages préliminaires menés en 1984 (Gallia, 1985 : 308), des fouilles ont été entreprises à l'intérieur du castellum et sur le système défensif ainsi que des études géophysiques pour délimiter l'emprise de la villa romaine, presque entièrement détruite (Wood, 1984, 1985, 1986, 1987, 1988, 1989). Les vestiges de la zone 1 et de la zone 2 (Fig. n°1 : Plan général des structures fouillées de 1984 à 1987) sont les reste..

Entropy of Li intercalation in LixCoO2

The entropy of lithiation of LixCoO2 for 0.5 < x less than or equal to 1.0 was determined from measurements of the temperature dependence of equilibrated voltages of electrochemical cells. Measured changes in the entropy of the lithiation reaction were as large as 9.0 k(B)/atom, and as large as 4.2 k(B)/atom within the "O3" layered hexagonal structure of LixCoO2. Three contributions to the entropy of lithiation for the O3 phase were assessed by experiment and calculation. The phonon entropy of lithiation was determined from measurements of inelastic neutron scattering. Phonon entropy can account for much of the negative entropy of lithiation, but its changes with lithium concentration were found to be small. Electronic structure calculations in the local density approximation gave a small electronic entropy of lithiation of the O3 phase. The configurational entropy from lithium-vacancy disorder was large enough to account for most of the compositional trend in the entropy of lithiation of the O3 phase if ordered structures exist at lithium concentrations of x=1/2 and x=5/6. The electrochemical measurements showed the existence of a two-phase region in the composition range between x=5/6 and 0.95. Electronic structure calculations gave evidence that these phases were metallic and insulating, respectively. Changes of the electronic and configurational entropy were found to be of comparable importance for this metal-insulator transition

Epeoloides pilosulus (Cresson) Rediscovered in Michigan, with Notes on the Distribution and Status of its Macropis hosts.

Epeoloides pilosulus (Cresson 1878) is one of the rarest bees in North America with only a handful of records since 1960. The last collection in Michigan was made in 1944. Epeoloides pilosulus is a brood parasite of Macropis bees, which until recently had not been collected in Michigan for several decades. Bee surveys in Midland County, Michigan have led to the rediscovery of E. pilosulus in this state – the first record in 74 years. Michigan becomes the fourth state where E. pilosulus has been rediscovered after Connecticut in 2006, New York in 2014 and Maine in 2016, and the sixth region in North America after Nova Scotia in 2002 and Alberta in 2010. State-wide bee surveys have also shown that the principal host, Macropis nuda (Provancher 1882), remains widespread in Michigan, and that Macropis patellata Patton 1880 is newly recorded for the state