A research project submitted to the University of the Witwatersrand, Faculty of Humanities, Wits School of Education, in partial fulfilment of the requirements for the degree of Master of Science in Science Education. November 2014 / This study was on the investigation of the effectiveness of the Sci-Bono outreach programme in the teaching of electrochemistry at grade11. Two aspects were used to measure effectiveness. The first aspect was a change in learners’ ability to answer questions before and after intervention. The second aspect was the programme’s ability to eliminate common misconceptions in electrochemistry. A sample of five schools was used in the study. At each school a pre-test was given to learners before intervention and a similarly structured and equally difficult task was given after intervention as a post-test. The marks for each learner were compared and the results for each school were analysed using a Wilcoxon signed rank test and a paired data test. Results from both methods of analysis reflected significant improvement in learners’ ability to answer questions after intervention at all five schools that made the sample of the research. A question by question analysis was also done to check a change learners’ ability to answer specific questions. Improvement in answering particular questions differed significantly, pointing out that certain concepts had been grasped better than others. Interviews were held with both learners and their teachers. These interviews were held to try and determine the extent to which misconceptions had been identified and eliminated. Pre-tests and post-test analysis reflected that one common misconception, where learners define oxidation and reduction in terms of addition and removal of oxygen was completely eliminated. Learner interviews however reflected a 75% success rate in the elimination of the misconception. Analysis of pre-tests and post-test results also showed a 75% success rate in the elimination of a misconception of the second misconception, where learners take an oxidising agent as a substance that has been oxidised and a reducing agent as a substance that has been reduced, compared to 76% from analysis of the learners’ interview results. Teacher interview results also reflected that the Sci-Bono outreach programme is to a high degree able to eliminate common misconceptions electrochemistry. From lesson observation and teacher interviews another misconception came to light. The misconception held by some learners is that ‘the oxidation number is the number of oxygen atoms in the molecule of a compound.’ This misconception was also tackled. During teachers’ interviews it emerged that all host teachers perceive the Sci-Bono Subject Matter Experts as effective in eliminating the identified common misconceptions in electrochemistry. The researcher is convinced that the Sci-Bono outreach programme improves the learners’ ability to answer questions in electrochemistry and that they address misconceptions in their teaching. The intervention however does not completely eliminate common misconceptions in electrochemistry. The Sci-Bono outreach programme is thus only effective to a certain extent in the teaching of electrochemistry at grade 11. The study also revealed that the teachers at schools expect the Sci-Bono Subject Matter Experts to have better pedagogical skills and they also expect them to bring scarce resources when they visit schools. They expect them to be able to tackle all formal and informal experiments covered in the grade11 curriculum. They believe that, in addition to enabling the elimination of misconceptions, the practicals carried out by the Sci-Bono SMEs also enhance understanding and provide practical skills to learners.

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Effective theories have applications in many areas of physics, from Newtonian mechanics through to condensed matter physics. In this thesis we discuss effective field theories in the context of constructing nucleon-nucleon interactions in a systematic and model-independent way. We start with the examination of the spin-singlet P-wave, by using distorted wave methods to remove the effects of long-range pion-exchange forces from the empirical 1P1 phase shift. The divergence appearing in this channel is renormalised using a counterterm that is provided by the relevant (Weinberg) power counting. This leaves an effective interaction strength that can be analysed, and from which one can extract an approximate scale for the underlying physics. We determine this scale to be close to the delta-resonance. We then turn to coupled (spin-triplet) waves, focussing predominantly on the 3S1-3D1 wave that contains the deuteron - an important system to understand in the context of nuclear forces. Starting with the 3S1-3D1 scattered waves, we again remove long-range pion-exchange forces from the empirical phase shifts, and extract an effective interaction matrix. The element that suffers from a divergence can be renormalised using counterterms provided by a renormalisation group analysis. Switching to negative energies we look for the deuteron boundstate, which is loosely bound and so pion physics plays an important role. Using the counterterms provided at positive energies, we extrapolate to the boundstate and treat this, two-pion-exchange and recoil one-pion-exchange as a combined perturbation to the system. We then use perturbation theory techniques to calculate the first-order correction to the energy and wave function, from which we calculate some deuteron observables.

This dissertation concerns modeling two aspects of dynamics of complex networks: (1) response dynamics and (2) growth and formation. A particularly challenging class of networks are ones in which both nodes and links are evolving over time – the most prominent example is a financial network. In the first part of the dissertation we present a model for the response dynamics in networks near a metastable point. We start with a Landau-Ginzburg approach and show that the most general lowest order Lagrangians for dynamical weighted networks can be used to derive conditions for stability under external shocks. Using a closely related model, which is easier to solve numerically, we propose a powerful and intuitive set of equations for response dynamics of financial networks. We find the stability conditions of the model and find two phases: “calm” phase , in which changes are sub-exponential and where the system moves to a new, close-by equilibrium; “frantic” phase, where changes are exponential, with negative blows resulting in crashes and positive ones leading to formation of "bubbles". We empirically verify these claims by analyzing data from Eurozone crisis of 2009-2012 and stock markets. We show that the model correctly identifies the time-line of the Eurozone crisis, and in the stock market data it correctly reproduces the auto-correlations and phases observed in the data. The second half of the dissertation addresses the following question: Do networks that form due to local interactions (local in real space, or in an abstract parameter space) have characteristics different from networks formed of random or non-local interactions? Using interacting fields obeying Fokker-Planck equations we show that many network characteristics such as degree distribution, degree-degree correlation and clustering can either be derived analytically or there are analytical bounds on their behaviour. In particular, we derive recursive equations for all powers of the ensemble average of the adjacency matrix. We analyze a few real world networks and show that some networks that seem to form from local interactions indeed have characteristics almost identical to simulations based on our model, in contrast with many other networks.

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

<p><p>The aim of this study was to identify and analyze why parents choose independent schools for their children. The survey was carried out using a total survey addressed to all parents with children in three independent schools in a medium-sized municipality. Two of the schools have a specially oriented pedagogy, Waldorf and Montessori while the third school has general direction. Parents were asked to answer questionnaires with closed questions and calls for comments. We found three categories of reasons for the choice, namely the educational motives, social motives and availability. The social motives proved to be the most important but also pedagogical reasons had certain significance when parents searched for an independent school. The parents sought from that the public school the child would belong to had shortcomings. A major reason in this regard was that bullying occurred in the past. Comparisons between parents grouped in different ways shows that it is the differences between the parents at the various schools. When parents are grouped by income and education the difference between the groups are very limited. We cannot find that the parents received any information that they have been able to base their choice of school. Choice seems rational, but unfounded.</p></p> / Education, Rational Elections, School Choice, Private Schools, Effective Schools, Neoliberals, Welfare Criticizer, Ideology

Thesis (M.A.)--University of North Carolina at Wilmington, 2006. / Vita. Includes bibliographical references and index.

Eco Log AB i Söderhamn är en tillverkare av skogsmaskiner. De tillverkar både skotare och skördare. På deras skördare sitter fyra pendelarmar som ersätter hjulupphängningen på fordonet. Dessa motverkar att fordonet lutar vid körning i sluttningar. Varje pendelarm drivs av en hydraulkolv som justerar nivelleringen. Då inga beräkningar med avseende på utmattning och livslängd genomförts sedan en omkonstruktion av pendelarmarna är det nödvändigt att analysera och utvärdera pendelarmarna. Syftet med examensarbetet är att analysera ett antal, maximalt tre, av pendelarmens svetsfogar med avsikt på utmattning. Jämförelse mellan de tre olika utvärderingsmetoderna Effective notch stress, Nominell spänning och Hot spot kommer genomföras. På begäran av Eco Log redovisas ej några värden på beräknade livslängder och spänningar utan endast en jämförelse mellan de olika metoderna redovisas där Nominella spännings-metoden används som referensvärde. En inledande spänningsanalys på en pendelarm på deras största skördare, Eco Log 590D, genomfördes. Denna analys, där endast en förenklad pendelarm användes, visade att det mest belastade svetsförbandet befann sig i nivå med infästningen av lagret i ytterlådans konstruktion. Detta svetsförband analyserades sedan vidare med avseende på utmattning. De mer noggranna utmattningsanalyserna baserades på tre olika utvärderingsmetoder för spänningar, Hot spot-, Effective notch stress- och Nominella spännings-metoden. Hot spot-metoden inkluderar membranspänningar och böjspänningar för det utvalda svetsförbandet. Effective notch stress inkluderar mebramspänningar, böjspänningar och den olinjära spänningstoppen för att kunna analysera spänningskoncentrationer i svetsrot eller tå. Nominella spänningar inkluderar normalspänningar. Genom att modellera det utvalda svetsförbandet med dessa tre metoder erhölls information om den maximala spänningsvidden. Denna spänningsvidd applicerades sedan i en arbetsgång för utmattningsberäkningar där en livslängd beräknades fram. Denna livslängd blev för Nominella och Effective notch-metoden blev densamma och för Hot spot-metoden blev den dubbelt så lång. Denna beräkningsgång baseras på International Institute of Welding.Denna beräknade livslängd var betydligt mindre än vad Eco Log hade förväntat sig. Dock är osäkerheten vid beräkningar och test med avseende på utmattning stor och därav borde även provning genomföras för att säkerställa livslängden. / Eco Log AB is a manufacturer of forestry equipment. They manufacture both forwarders and harvesters. On their harvesters there are four pendulum arms that replace the suspension on their vehicles. The pendulum arms anti tilts the vehicle when driving in slopes. Every pendulum arm is individually driven by hydraulic cylinders that adjust the leveling. Given that no calculations with respect to fatigue and service life since a redesign were made, analysis and evaluation of the pendulum arm was necessary. The purpose of this thesis is to analyze an number of, maximum three, of the pendulums welds with respect to fatigue. Comparison between three different evaluation methods Effective notch stress, Nominal stress and Hot spot will be conducted. On request from Eco Log no values regarding calculated service lifetime and stress will be presented, only a comparison between the different methods were the Nominal stress-method is used as reference. An initial stress analysis on the pendulum arm on their largest harvester, the Eco Log 590D, was conducted. This analysis, which only used a simplified pendulum arm, indicated that the most load carrying load were located at the attachment of the bearing thus on the outer box-constructuib. This welded joint was then further analyzed with respect to fatigue. These fatigue analysis was based on three different evaluation methods, Hot spot-, Effective notch stress- and Nominal stress-method. The Hot spot method includes membrane stress and bending stress for the selected weld. Effective notch stress includes membrane stress, bending stress and the nonlinear stress peak in order to analyze stress concentration in the weld root and weld toe. Nominell stress includes normal stresses. By constructing the selected welded joint with these three evaluation methods, information regarding the maximal stress range was given. This stress range was then applied to a specific working procedure for fatigue calculations were the results obtained in expected service-life. The service-life for the Nominal and Effective notch stress-method were almost identic meanwhile for the Hot spot-method the service-life was twice as long. This working procedure is based on the International Institute of Welding. This calculated service-life were significantly less than what Eco Log had expected. The uncertainty of calculation for fatigue is however big and therefore testing should also be carried out to ensure the service life of pendulum arm.

The aim of this study was to identify and analyze why parents choose independent schools for their children. The survey was carried out using a total survey addressed to all parents with children in three independent schools in a medium-sized municipality. Two of the schools have a specially oriented pedagogy, Waldorf and Montessori while the third school has general direction. Parents were asked to answer questionnaires with closed questions and calls for comments. We found three categories of reasons for the choice, namely the educational motives, social motives and availability. The social motives proved to be the most important but also pedagogical reasons had certain significance when parents searched for an independent school. The parents sought from that the public school the child would belong to had shortcomings. A major reason in this regard was that bullying occurred in the past. Comparisons between parents grouped in different ways shows that it is the differences between the parents at the various schools. When parents are grouped by income and education the difference between the groups are very limited. We cannot find that the parents received any information that they have been able to base their choice of school. Choice seems rational, but unfounded. / Education, Rational Elections, School Choice, Private Schools, Effective Schools, Neoliberals, Welfare Criticizer, Ideology