Dissertations / Theses: 'Secondary Physics'

1

Boggs, Aaron M. "Alternative assessment in the secondary physics classroom." Muncie, Ind. : Ball State University, 2009. http://cardinalscholar.bsu.edu/695.

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2

Bolouri, H. "Secondary ion emission." Thesis, University of Salford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.353964.

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3

Blickenstaff, Jacob Arin. "A framework for effective physics education applied to secondary and university physics courses /." For electronic version search Digital dissertations database. Restricted to UC campuses. Access is free to UC campus dissertations, 2004. http://uclibs.org/PID/11984.

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4

Lee, Allen S. M. Massachusetts Institute of Technology. "Symmetry-breaking motility and RNA secondary structures." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/34396.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Physics, 2005.
Includes bibliographical references (p. 61-64).
This thesis contains work on three separate topics: the spontaneous motility of functionalized particles, the designability of RNA secondary structures, and the statistical mechanics of homopolymer RNAs. For the work on spontaneous motility, we were motivated by in vitro experiments investigating the symmetry-breaking motility of functionalized spherical beads to develop a general theory for the dynamics of a rigid object propelled by an active process at its surface. Starting from a phenomenological expansion for the microscopic dynamics, we derive equations governing the macroscopic velocities of the object near an instability towards spontaneous motion. These equations respect symmetries in the object's shape, with implications for the phase behavior and singularities encountered at a continuous transition between stationary and moving states. Analysis of the velocity fluctuations of such an object reveals that these fluctuations differ qualitatively from those of a passive object. For the work on designability, we investigated RNA folding within a toy model in which RNA bases come in two types and complementary base pairing is favored. Following a geometric formulation of biopolymer folding proposed in the literature, we represent RNA sequences and structures by points in a high-dimensional "contact space." Designability is probed by investigating the distribution of sequence and structure points within this space. We find that one-dimensional projections of the sequence point distribution approach normality with increasing RNA length N.
(cont.) Numerical comparison of the structure point distribution with a Gaussian approximation generated by principal component analysis reveals discrepancies. The third and final project concerns the statistical mechanics of homopolymer RNAs. We compute the asymptotics of the partition function Zn and characterize the crossover length scale governing its approach to its leading asymptotic behavior. Consideration of restricted partition functions in which one or more base pairs are enforced leads to an interesting connection with ideal Gaussian polymers. We introduce the notion of gapped secondary structures and analyze the partition function Z?,) for RNAs of length n with gap at p. Another length scale emerges whose scaling agrees with that of the crossover scale found earlier.
by Allen Lee.
S.M.

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5

Kgwadi, Ntate Daniel. "Inexpensive conceptual experiments/demonstrations for physics teaching." Virtual Press, 1992. http://liblink.bsu.edu/uhtbin/catkey/834635.

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Current research on cognitive learning is applied to the designing of several experiments for use in high school physical science and physics classes. The goal of the project was to use simple inexpensive materials to construct experiments and demonstrations that illustrate physics concepts and can easily be modeled using simple mathematics.Saline solutions are used to show simple examples of refraction and effects of a solution of varying density. The refractive index of two liquids is measured. The continuous refraction of a stratified fluid is demonstrated. Fluid flow is investigated. This leads to a simple experiment that leads to an easy way to measure the acceleration of gravity.The goal was met with several simple experiments using inexpensive materials, modeling techniques, and simple mathematics derivations were designed and tested. Data from the experiments gives results that are very close to the accepted values.
Department of Physics and Astronomy

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Sauerwine, Benjamin Adair. "Secondary Structure Models of Nucleic Acid Folding Kinetics." Research Showcase @ CMU, 2011. http://repository.cmu.edu/dissertations/103.

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This thesis examines nucleic acid folding processes using secondary structure models, which have the advantage that they may simulate behavior at long timescales. First, it verifies that Kinetic Monte Carlo can reproduce known behavior of biological riboswitches. Motivated by the results of that study, a new and general method for determining the effective barrier between local free energy minima is introduced. Finally, a general rate model is developed that greatly improves simulated agreement with measured dynamic properties by considering the energy of intermediates outside the state space of secondary structure.

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7

Leeson, Alistair M. "Time-of-flight secondary ion mass spectroscopy of polymer surfaces." Thesis, University of Sheffield, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268294.

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8

Kozlonskie, Laura M. "Physics and chemistry for pre-secondary students in New Zealand." Thesis, University of Canterbury. Physics, 2004. http://hdl.handle.net/10092/5926.

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In 1996 we set out to show that primary teachers could teach the new physical science curriculum with no further training if they had the right books. We searched the literature for didactics which had been shown to positively impact learning so that we could incorporate those features into any books we would make. We conducted a pilot project for which we wrote and printed 30 workbooks for one activity. Next, we sent out a book survey to find what books were available for the subject in New Zealand at that time. Simultaneously, we scoured Europe, Asia and North America for good lesson material. We found material which incorporated the didactic criteria from our literature search and adapted some of it for our study, producing about 12,000 guided workbooks for each of the last four pre-secondary years, 3000 for each age nine to twelve. The books were made available to all New Zealand schools. Two groups of about 12 teachers each formally trialled the books. One group answered questionnaires and the other kept action research journals. Both groups confirmed the principal research premise- teaching hours increased with no further training. Once good books were in hand other problems became apparent. A nationwide resources survey revealed a lack of equipment and other problems such as poor classroom design, awkward grouping of children of different ages and abilities, lack of time, dysfunctional open plan classes of 100 pupils, two-year teaching cycles, competition from free resource packs, and lack of support material such as videos. From this study it can be concluded that the books made a positive impact for teaching physical science. The books gave teachers an international standard of lessons to work from. It was shown by this study that a teacher with no background in physics or chemistry can teach primary physical science at an international standard once good books are in hand as long as poor equipment, space and facilities are not too serious a set of impediments.

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Chetcuti, Deborah Anne. "The Physics Secondary Education Certificate examination : a Maltese case study." Thesis, Nottingham Trent University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266926.

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Sverin, Tomas. "Open-ended problems in physics : Upper secondary technical program students’ ways of approaching outdoor physics problems." Thesis, Umeå universitet, Institutionen för naturvetenskapernas och matematikens didaktik, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-52486.

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This study reports on technical program students’ approaches to solving open-ended problems during an introductory physics course in a Swedish upper secondary school. The study used case study methodology to investigate students’ activities in outdoor context. The findings come from observations and audio recordings of students solving three different open-ended problems. The results showed that the students had difficulties to formulate ‘solvable’ problems and to perform necessary ‘at home’ preparations to be able to solve the problems. Furthermore, students preferred to use a single solution method even though different solution methods were possible. This behavior can be attributed to their previous experience of solving practical problems in physics education. The result also indicated need of different levels of guidance to help the students in their problem solving process. A tentative conclusion can be made that open-ended problems have an educational potential for developing students’ understanding of scientific inquiry and problem solving strategies in the process of performing practical outdoor activities.

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Test, Harold G. (Harold Goldson). "A Comparison of Physics Enrollments in Selected Large Texas Secondary Schools." Thesis, North Texas State University, 1985. https://digital.library.unt.edu/ark:/67531/metadc331038/.

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The problem of this study is twofold. The first is to discover in what ways are physics teachers and counselors in large Texas public secondary schools encouraging students to take physics, and second, what are their perceptions of reasons for student avoidance of physics. The population consisted of physics teachers and counselors in large (1,310 minimum enrollment) high and low percentage physics enrollment schools. Percentage enrollment in physics is defined as the number of students enrolled in physics compared to total twelfth grade enrollment. Thirty high (above 8.9) and thirty low (below 8.0) percentage enrollment schools comprise the sample population. Data were collected using separate questionnaires that related to (a) school, (b) physics teacher, and (c) counselor variables that could affect physics enrollments. The questionnaires addressed to perceptions of both physics teachers and counselors covered (a) the exchange of physics course information between students, teachers, and counselors, (b) the method of exchange of physics course information, and (c) the extent to which the physics program is sold to the student body. Also elicited were eleven responses from both physics teachers and counselors that pertain to perceived reasons for student avoidance of physics courses. A statistical analysis was made between physics teachers and counselors perceptions pairing high and low percentage enrollment groups by chi square analysis of each item of the questionnaire, using a .05 level for significance.

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Lam, Wai-Keung. "Implementation of investigative study in new senior secondary school physics curriculum /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?PHYS%202006%20LAM.

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Kapucu, Serkan. "Physics Teachers." Phd thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614422/index.pdf.

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The purpose of this study was to investigate four in-service physics teachers&rsquo
beliefs related to Turkish High School Physics Curriculum (THSPC) and to what extent these beliefs are reflected in their instructional practices. Data were collected through interviews, classroom observations and an open-ended questionnaire. Teachers&rsquo
responses to interview questions showed that they believed that teaching physics according to the THSPC helped students use their skills, become interested in physics lessons, relate physics to their daily life and have a permanent knowledge. Besides, teachers believe that they can teach physics according to the THSPC generally by giving examples from daily life and creating a discussion environment. The data obtained from classroom observations showed that the beliefs of teachers about how to teach physics according to the THSPC were reflected in their instructional practices. Teachers&rsquo
responses to open-ended questionnaire showed that teachers believed the necessity of attainment of majority of the skill objectives in the THSPC by students. However, they do not consider that students can attain many of the problem solving and information and communication skills. The data obtained from classroom observations showed that they seldom attempted to help students attain them or they never attempted. The data gathered from interviews and an open questionnaire showed that there were some factors that influence teachers&rsquo
instructional practices according to the THSPC. For example, they believe that students&rsquo
interest in physics lessons and teacher&rsquo
s opportunity to give more examples about daily life made their teaching physics according to the THSPC easy. However, they believe that university entrance exam, inadequacy of laboratory environment and lesson hours, students&rsquo
low economic status and lack of information and communication technologies affected their teaching physics according to the THSPC negatively.

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Roebber, Elinore. "Large-scale secondary polarization of the cosmic microwave background." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=110739.

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We present two examples of secondary effects on the large-scale polarization of the cosmic microwave background (CMB). We begin with a review of the standard model of cosmology, as well as the predictions of bulk flows by the linear theory of structure growth and the mathematical formalism of polarization. Following this review, we explore the impact of the epoch of reionization on the large-scale polarization of the CMB, paying particular attention to the effects of an alternate reionization history containing dark stars. Subsequently, we derive the CMB polarization signature of large-scale bulk flows and examine its potential for detection by future experiments.
Nous présentons deux exemples d'effets secondaires sur la polarisation du fond diffus cosmologique (CMB) à grande échelle. Nous débutons avec une revue du modèle standard de la cosmologie, une prédiction des mouvements d'ensemble des amas de galaxies par la théorie de la croissance linéaire des structures ainsi qu'une présentation du formalisme mathématique de la polarisation. Suivant cette revue, nous étudions l'impact de l'époque de réionisation sur la polarisation à grande échelle du CMB, en se concentrant sur les effets d'un modèle alternatif de réionisation incluant des étoiles sombres. Ensuite, nous dérivons la signature en polarisation dans le CMB engendrée par un mouvement d'ensemble à grande échelle et examinons la mesurabilité de ce signal par des expériences futures.

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15

Saunders, Jessica. "Secondary prompt gamma-rays to improve proton range verification." Diss., Georgia Institute of Technology, 2016. http://hdl.handle.net/1853/55003.

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The goal of this research is to evaluate the secondary prompt gamma (PG) yield from proton therapy at high characteristic energies from MC model simulations and experimental data. Recent studies indicate that target composition influences PG characteristic energy and yield, and the quantification of PG may be used to offer real-time dose verification for proton therapy. In this study PG analysis was performed for MC simulations to evaluate the characteristic measurements and total yield of secondary PG emitted from a target in the 0-8 MeV range from a proton therapy beam over a range of four different beam energies (70 MeV, 160 MeV, 200 MeV, 220 MeV). This was repeated in several target materials (carbon, calcium oxide, calcium fluoride, PMMA, and HDPE) in order to evaluate the influence of the incident energy and the target material on the PG yield and energy spectra. PG energy spectra determined from the specified target materials indicated that the 3.74 MeV energy peak shows a linear correlation between PG intensity and calcium mass fraction of the target material. 6.13 MeV and 4.44 MeV energy peak are not unique to the respective, oxygen and combined oxygen and carbon, mass fraction of the target material. This relationship is complicated by the addition of calcium within the target. Experimental data was collected in order to validate the computational model based on comparison of relative characteristic energy peek intensities. The relative peak ratio determined from experimental data is in good agreement with model prediction, the combined peak ratio is within 0.2%.

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16

Bouma, Craig E. "Physics First| Impact on SAT Math Scores." Thesis, Loyola Marymount University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3610316.

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Improving science, technology, engineering, and mathematics (STEM) education has become a national priority and the call to modernize secondary science has been heard. A Physics First (PF) program with the curriculum sequence of physics, chemistry, and biology (PCB) driven by inquiry- and project-based learning offers a viable alternative to the traditional curricular sequence (BCP) and methods of teaching, but requires more empirical evidence. This study determined impact of a PF program (PF-PCB) on math achievement (SAT math scores) after the first two cohorts of students completed the PF-PCB program at Matteo Ricci High School (MRHS) and provided more quantitative data to inform the PF debate and advance secondary science education. Statistical analysis (ANCOVA) determined the influence of covariates and revealed that PF-PCB program had a significant (p < .05) impact on SAT math scores in the second cohort at MRHS. Statistically adjusted, the SAT math means for PF students were 21.4 points higher than their non-PF counterparts when controlling for prior math achievement (HSTP math), socioeconomic status (SES), and ethnicity/race.

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17

Wu, Qiong. "Measurements and studies of secondary electron emission of diamond amplified photo cathode." [Bloomington, Ind.] : Indiana University, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3337275.

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Thesis (Ph.D.)--Indiana University, Dept. of Physics, 2008.
Title from PDF t.p. (viewed on Jul 29, 2009). Source: Dissertation Abstracts International, Volume: 69-12, Section: B, page: 7588. Adviser: Shyh-Yuan Lee.

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18

Jia, Yi Ph D. Massachusetts Institute of Technology. "Measurement of secondary cosmic rays lithium, beryllium, and boron by the alpha magnetic spectrometer." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/119902.

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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Physics, 2018.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 113-122).
Secondary cosmic rays are mainly produced by the collisions of nuclei with the interstellar medium. The precise knowledge of secondary cosmic rays is important to understand the origin and propagation of cosmic rays in the Galaxy. In this thesis, my work on the precision measurement of secondary cosmic rays Li, Be, and B in the rigidity (momentum/charge) range 1.9 GV to 3.3 TV with a total of 5.4 million nuclei collected by AMS is presented. The total error on each of the fluxes is 3%-4% at 100 GV, which is an improvement of more than a factor of 10 compared to previous measurements. Unexpectedly, the results show above 30 GV, these three fluxes have identical rigidity dependence and harden identically above 200 GV. In addition, my work on a new method of the tracker charge measurement leads to significant improvements in the AMS charge resolution, thus paving the way for the unexplored flux measurements of high Z cosmic rays.
by Yi Jia.
Ph. D.

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19

Januário, Francisco Maria. "Investigating and improving assessment practices in Physics in secondary schools in Mozambique." Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-09252008-161339/.

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Chester, Victor. "The relationship between cooperative learning and physics achievement in minority students." ScholarWorks, 2009. https://scholarworks.waldenu.edu/dissertations/784.

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Minority students lag Caucasian students in science performance and are underrepresented in the fields of science and technology. It is therefore pivotal for minorities, African American and Hispanic students, to show improved performance in science education. The purpose of this study was to investigate the impact of cooperative learning strategy on physics achievement by high school minority students. Constructivism formed the theoretical framework for the study. Independent learning, the traditional strategy, and cooperative learning dyads, the novel intervention, were the independent variables, and the dependent variable was achievement in physics. A repeated measures design and a convenient sample group of students were used in this study. Difference of scores obtained from the performances of the group as independent and cooperative learners was subjected to a repeated measures t test. A significant relationship between cooperative learning dyads and physics achievement by high school minority students was found. By learning in small groups, students were able to help each other construct meaning and make sense of their learning. Further study was recommended to foster cooperative learning strategy in minority classes and among science teachers of high schools with a majority of minorities. Social change is embedded in the study as increased achievement in science by minority students could possibly lead to advancement in science and technology careers for minorities and possibly close the gap that exists in science performance between minority and Caucasian students. This change could lead to a better social status for minorities.

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Owusu-Ware, Samuel. "Understanding correlations between secondary relaxations and thermal behaviour of biologically relevant molecules." Thesis, University of Greenwich, 2013. http://gala.gre.ac.uk/11388/.

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The research presented in this doctoral thesis examines the application of thermally stimulated depolarisation current (TSDC) spectroscopy as a probe of molecular mobility in the solid (powdered) state. TSDC spectroscopy has proved useful in understanding the molecular mobility of amorphous materials. However, few investigations have been undertaken in order to understand molecular mobility in crystalline and semi-crystalline solid-state (powder) materials and how mobility in such systems can be related to stability. Differential scanning calorimetry (DSC), including - where applicable - temperature modulated differential scanning calorimetry (TMDSC), and thermal gravimetric analyses (TGA) were employed to study the thermal behaviour/stability of the different molecular systems under scrutiny. Experiments on crystalline butyric acids, Î³-aminobutyric acid (GABA), DL-Î±-aminobutyric acid (AABA) and DL-Î²-aminobutyric acid (BABA), were undertaken in order to examine the influence of positional isomerism on molecular mobility and stability. These molecules differ in the position of the amine group relative to the carboxyl functionality. GABA, DL-BABA and DL-AABA were found to undergo localised non-cooperative rotational motions at 77 Â± 2Â°C and 114 Â± 2Â°C, 104 Â± 1Â°C and 109 Â± 1Â°C, respectively, prior to the higher temperature thermal events detected via DSC and TGA. The carbon chain length between the amino and the carboxyl moiety is found to be a key contributor to solid-state molecular mobility. Molecular relaxation frequency was found to correlate to thermal stability of the materials investigated i.e. the lower the relaxation frequency the greater the thermal stability. The molecular mobility of a homologous series of semi-crystalline phosphatidylcholines: 1,2-dilauryl-sn-glycero-3-phosphocholine (DLPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) with acyl chain lengths of 12, 14, 16 and 18, respectively has been examined at temperatures below the chain melting transition temperature (Tm). The results show that increasing the acyl chain length increases the temperature at which molecular mobility is observed i.e. the temperature maxima (Tmax) of the global relaxation processes occur at 41 Â± 2, 47 Â± 2, 57 Â± 2 and 67Â± 3Â°C for DLPC, DMPC, DPPC and DSPC, respectively. The molecular mobilities of the phosphatidylcholines are hypothesized to involve both inter- and intra-molecular co-operation and originate from the segmental motion of the diacyl backbone. The relaxation times (21 Â± 2, 19 Â± 3, 25 Â± 1 and 32 Â± 4 s for DLPC, DMPC, DPPC and DSPC, respectively) are shown to correlate with the apparent activation energy (Ea) and Tm values of the phosphatidylcholines. Studies of lyophilized peptide/proteins namely insulin, lysozyme and myoglobin were investigated in the hydrated and dehydrated state in the temperature range -150 to 150Â°C. This body of work attempts to understand if and how moisture and/or parameters associated with structure influence molecular mobility of lyophilized peptide/proteins. The results show that the presence of low levels of moisture content (<10%) facilitates molecular mobility at sub-zero temperatures; no mobility is observed in the sub-zero temperature regions after dehydration. The temperature locations of the relaxation processes in the proteins containing moisture are -95 Â± 3, -102 Â± 3 and 111 Â± 2Â°C for insulin, lysozyme and myoglobin, respectively. Whilst the temperature location of the relaxation processes in the dehydrated protein samples are 96 Â± 3, 72 Â± 4 and 82 Â± 3Â°C for insulin, lysozyme and myoglobin, respectively. It was found that the temperature order in which molecular mobility occurs correlates with the temperature order at which denaturation-decomposition processes occur for the three peptide/protein systems investigated. The work presented herein demonstrates the capability of TSDC spectroscopy to detect and characterise low energy transitions (secondary relaxations) that are inaccessible by conventional DSC methods. In addition, the ability to relate molecular mobility to thermal stability of materials examined has been established.

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Fox, Harvey Stuart. "A study of shallow implants in silicon by secondary ion mass spectrometry." Thesis, University of Warwick, 1989. http://wrap.warwick.ac.uk/99683/.

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This project investigates the analysis of shallow implants by secondary ion mass spectrometry (SIMS) and the problems that arise from it. Ion implantation is now almost exclusively used in the manufacture of modern very large scale integration devices. The quantification of these implants can be carried out very successfully by SIMS. However the distortions that are present in any SIMS analysis are emphasised when the implanted layer is less than lOOnm below the surface. In order to characterize these distortions, it is necessary to be able to accurately parameterize the implant profile. Taking moments of the data was found to be a reliable method of doing this without constructing a distribution. Once a parameterizing method was found the differential shift was investigated in silicon, with and without a Si-MBE grown capping layer. The results suggested that the differential shift may be a depth dependant phenomenon. The effect of the amorphization of a crystal on ion implantation was investigated with respect to the change in sputter rate going through the damaged region. The effect of uneven etching on this study is discussed in detail. In order to overcome this uneven etching two different raster scan units are discussed. One, is a new totally computer controlled device for use on a new SIMS instrument. The other is a modification to an existing scan unit. This second unit has been used to make craters that are flat to 0.05%.

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Davies, Robert. "Measurement of Angle-Resolved Secondary Electron Spectra." DigitalCommons@USU, 1999. https://digitalcommons.usu.edu/etd/1698.

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Theoretical formulations of secondary electron emission over the past 20 years have exceeded the confirming ability of available measurements. An instrument has been developed and tested for the purpose of obtaining simultaneous angle- and energy-resolved (AER) secondary and backscattered electron measurements for energetic electrons incident on conducting surfaces. The instrument is found to be in good working order and the data quality found to be excellent for nearly all angles and energies investigated. A representative set of AER measurements has been acquired for 1500 e V electrons normally incident on polycrystalline gold. The data have been used to construct angle-resolved (AR) spectra and energy-resolved (ER) angular distributions, which have been examined both as surface plots and cross sections. Analysis of the measurements strongly suggests that secondary electrons comprise the bulk of emitted electrons at energies much greater than the traditionally accepted maximum secondary electron energy of 50 eV. Additional evidence suggests the ability to investigate dominant secondary and backscattered electron production mechanisms in several energy domains.

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Thomson, Clint D. "Measurements of the Secondary Electron Emission Properties of Insulators." DigitalCommons@USU, 2005. https://digitalcommons.usu.edu/etd/2093.

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Measurements of the electron-induced electron emission properties of insulators are important to many applications including spacecraft charging, scanning electron microscopy, electron sources, and particle detection technology. However, these measurements are difficult to make since insulators can charge either negatively or positively under charge particle bombardment that in turn alters insulator emissions. In addition, incident electron bombardment can modify the conductivity, internal charge distribution, surface potential, and material structure in ways that are not well understood. A primary goal of this dissertation work has been to make consistent and accurate measurements of the uncharged electron yields for insulator materials using innovative instrumentation and techniques. Furthermore, this dissertation reports on the experimental work undertaken by our group to explore insulator charging rates as a function of incident electron energy and fluence. Specifically, these charging studies include: (i) the study of the effectiveness of charge-neutralization techniques such as low-energy electron flooding and UV light irradiation to dissipate both positive and negative surface potentials induced by incident electron irradiation, (ii) the exploration of several noncontacting methods used to determine insulator surface potentials and the insulator first and second crossover energies that are important in determining both the polarity and magnitude of spacecraft material potentials, (iii) the dynamical evolution of electron emissions and sample displacement current as a function of incident charge fluence and energy with ties to evolving surface potentials as an insulator reaches its current steady state condition, and (iv) the slow evolution of electron yields with continuous incident electron bombardment. These charging data are explained in the context of available insulator charging models. Specific insulator materials tested included chromic acid anodized aluminum, RTVsilicone solar array adhesives, and KaptonTM on aluminum.

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Coath, Christopher D. "A study of ion-optics for microbeam secondary-ion mass spectrometry." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335723.

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Sheaffer, Christopher Ryan. "Patterns in Nature Forming Patterns in Minds : An Evaluation of an Introductory Physics Unit." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/925.

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Educators are increasingly focused on the process over the content. In science especially, teachers want students to understand the nature of science and investigation. The emergence of scientific inquiry and engineering design teaching methods have led to the development of new teaching and evaluation methods that concentrate on steps in a process rather than facts in a topic. Research supports the notion that an explicit focus on the scientific process can lead to student science knowledge gains. In response to new research and standards many teachers have been developing teaching methods that seem to work well in their classrooms, but lack the time and resources to test them in other classroom environments. A high school Physics teacher (Bradford Hill) has developed a unit called Patterns in Nature (PIN) with objectives relating mathematical modeling to the scientific process. Designed for use in his large public school classroom, the unit was taken and used in a charter school with small classes. This study looks at specifically whether or not the PIN unit effectively teaches students how to graph the data they gather and fit an appropriate mathematical pattern, using that model to predict future measurements. Additionally, the study looks at the students' knowledge and views about the nature of science and the process of scientific investigation as it is affected by the PIN unit. Findings show that students are able to identify and apply patterns to data, but have difficulties explaining the meaning of the math. Students' show increases in their knowledge of the process of science, and the majority develop positive views about science in general. A major goal of this study is to place this unit in the cyclical process of Design-Based Research and allow for Pattern in Nature's continuous improvement, development and evaluation. Design-Based Research (DBR) is an approach that can be applied to the implementation and evaluation of classroom materials. This method incorporates the complexities of different contexts and changing treatments into the research methods and analysis. From the use of DBR teachers can understand more about how the designed materials affect the students. Others may be able to use the development and analysis of PIN study as a guide to look at similar aspects of science units developed elsewhere.

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Cherry, Anthony John. "Detection and characterisation of secondary relaxations in solids using thermally stimulated current spectroscopy." Thesis, University of Greenwich, 2013. http://gala.gre.ac.uk/11387/.

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Thermally stimulated current (TSC) spectroscopy has been used, in these reported investigations, as an innovative experimental technique for the detection and characterisation of secondary relaxation phenomena in the crystalline state for a number of low-molecular weight organic materials (LOMs), namely α-alanine, β-alanine, a co-crystal system (salicylic acid and benzamide) and the drug paracetamol (form I). The aim of the research was to significantly improve the contemporary understanding of secondary relaxation phenomena in crystalline LOMs; an area of science that is of significant inter-disciplinary interest throughout academia and industry. In all the materials examined, secondary relaxations were detected and characterised by TSC; in order to achieve the foregoing different experimental methodologies (e.g. thermal windowing) and data processing techniques (e.g. relaxation map analysis) were employed. Of significant prevalence throughout is the phenomenon of compensation behaviour; in both the thermodynamic (i.e. enthalpy and entropy compensation) and in the kinetic (i.e. pre-exponent and activation energy (of the Arrhenius equation)) sense. Derived compensation points were linked to real physical processes; identifying a relationship between secondary relaxations and primary transitions. It is proposed, herein, that secondary relaxations have a pre-requisite relationship with primary transitions. Secondary relaxations are preparatory motions, essential for primary transitions to occur. In addition, throughout this thesis, additional information on topics such as co-crystal synthesis, chirality, degradation, the nature of secondary/primary relaxations, the nature of primary transitions and physical properties of LOMs, are examined in relation to the LOMs under investigation. TSC has proven to be an effective, and perhaps unique, instrumental technique for the detection and characterisation of secondary relaxations in LOMs.

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Webb, Natalie. "The physics of late-type secondary stars and accretion discs in interacting binaries." Thesis, Keele University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268340.

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29

Tucek, John Christopher. "Collision-induced secondary electron and negative ion emission from metallic surfaces." W&M ScholarWorks, 1997. https://scholarworks.wm.edu/etd/1539623909.

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Absolute yields of negative ions and secondary electrons resulting from collisions of positive sodium ions (Na{dollar}\sp{lcub}+{rcub}){dollar} with polycrystalline aluminum (Al) and molybdenum (Mo) surfaces and the Mo (100) surface have been measured as a function of the oxygen (O) coverage, from none up to several monolayers, for impact energies, E {dollar}<{dollar} 500 eV. Negative oxygen ions (O{dollar}\sp{lcub}-{rcub}){dollar} are found to be the dominant sputtered negative ions and for the three surfaces at all O coverages and Na{dollar}\sp{lcub}+{rcub}{dollar} impact energies. The O{dollar}\sp{lcub}-{rcub}{dollar} and secondary electron yields share a common impact energy threshold at {dollar}\rm E\sb{lcub}th{rcub}\approx 50{dollar} eV, and both have a strong dependence on the oxygen coverage of the surface.;The kinetic energy distributions of the secondary electrons and sputtered O{dollar}\sp{lcub}-{rcub}{dollar} were determined as functions of O coverages and impact energies. The O{dollar}\sp{lcub}-{rcub}{dollar} distributions are characterized by a narrow, low energy peak (at {dollar}\sim{dollar}1-2 eV) followed by a low level, high energy tail. The secondary electrons have a narrow (FWHM {dollar}\sim{dollar} 1-2 eV) kinetic energy distribution, centered essentially at the same most probable kinetic energy as the ions. The shapes of the respective distributions and the most probable kinetic energies are essentially invariant with the impact energy, O coverage and the metal surface.;The results were analyzed in terms of conventional collision cascade model, but the calculation could not be fitted to the experimental results. An electronic excitation mechanism is proposed to augment the collision cascade and to provide a mechanism for secondary electron emission. In the model, adsorbed O, which resides on the surface essentially as O{dollar}\sp{lcub}-{rcub},{dollar} is collisionally excited into an (MO{dollar}\sp{lcub}-{rcub})\sp*{dollar} repulsive state, and as the O{dollar}\sp{lcub}-{rcub}{dollar} exits the surface along the surface potential energy curve, it can decay by emission of an electron to the metal or to the vacuum, or it can survive as an ion. The parameters of this model can be adjusted such that the calculated kinetic energy distribution, together with that of the collision cascade, can reasonably reproduce the experimental observations for the ions and provide a reasonable fit to the corresponding electron kinetic energy distributions as well.

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30

Checkley, Doug, and University of Lethbridge Faculty of Education. "High school students' perceptions of physics." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Education, 2010, 2010. http://hdl.handle.net/10133/2584.

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There are far fewer high school students enrolled in physics than in chemistry or biology courses within the province of Alberta (Alberta Education, 2007). Students are also completing the highest level math course in larger numbers than those taking physics. It appears that a fear of physics exists within students in our province; this fear seems to be related to a level of difficulty the students associate with physics. Many students either opt to not take physics or enter the course with the expectation of failure. In this study I explored the impact of physics’ reputation upon a group of students who chose not to take physics. In addition, I attempted to determine whether the perception of the difficulty of high school physics is accurate. This was done by investigating the perceptions of several students who took physics. I surveyed students from one high school in a small urban school district using group interviews. The students were in grades 10 to 12 and divided into groups of Science 10, Physics 20 and Physics 30 students. The students were interviewed to gain a deeper understanding of what perceptions they have about physics and why they may have them, hoping to identify factors that affect their academic decision to take or not take physics classes. For the students interviewed, I found that the biggest influence on their decisions to take or not take physics was related to their future aspirations. The students were also heavily influenced by their perceptions of physics. The students who took physics claimed that physics was not as difficult as they had believed it to be and they reported that it was interesting, enjoyable and relevant. Those students who had chosen to not take physics perceived it would be difficult, irrelevant and boring. Therefore, a major difference of perception exists between the students who took physics and those that did not.
viii, 221 leaves ; 29 cm

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31

Carrera, Marco. "Variability in the simulation of a case of secondary cyclogenesis with a mesoscale model." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1996. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/MQ37308.pdf.

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32

Cooke, Graham Alan. "The development of secondary ion mass spectrometry for two-dimensional impurity profiling in semiconductors." Thesis, University of Warwick, 1992. http://wrap.warwick.ac.uk/109531/.

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As the dimensions of devices on integrated circuits are reduced, the importance of lateral spreading of implanted impurities increases. To maintain inter-device isolation and predictable performance, knowledge of the extent and concentration of these regions is necessary. A number of computer models have been produced to predict this information, however there is a serious lack of experimental data with which to verify their results. Secondary Ion Mass Spectrometry (SIMS) has been used for many years to provide depth profiles with high sensitivity and depth resolution, however, direct application of SIMS will not yield multi-dimensional results with enough spatial resolution and sensitivity to be useful. This is because the analyte volume is very limited. This thesis describe the development of a technique that increases the volume available for analysis by means of a special sample. The sample geometry introduces an inherent magnification that permits the use of a relatively large, low energy, reactive ion probe. This in tum provides high sensitivity - due to enhanced secondary ion yields - and good depth resolution - due to the low range of the probe. Using a quadrupole SIMS instrument, and a 50 μm FWHM oxygen probe, spatial resolutions of less than 70 nm have been demonstrated with a sensitivity of better than 1017 atoms cm3 for boron implants in silicon.

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33

Lai, Chi-shing, and 黎志誠. "An inquiry into teachers' concerns in their organization of practical work in school physics." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1994. http://hub.hku.hk/bib/B31957171.

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34

Mabodoko, Mkhumbuzi Joe. "A phenomenological investigation into the lived experiences of grade 12 Physical Sciences learners from selected schools in the Western Cape Province." Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2565.

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Thesis (MEd (Education))--Cape Peninsula University of Technology, 2017.
This study aims to narrate the lived experiences of Grade 12 Physical Sciences learners. According to UMALUSI reports on National Senior Certificate (NSC) of 2011 and 2013, there seems to be a steady decrease in the number of learners writing Physical Sciences from 2008 to 2013. One of the aims of this study is to investigate why there is a steady decline in the number of learners choosing the subject and what their classroom experiences are. A related aim is to describe how these learners’ perceptions of their Physical Sciences educators affect their mental experiences in the subject. The study used phenomenology both as a research methodology as well as the underpinning theoretical framework. Twelve Grade 12 learners from 3 different schools in the Metro North Education District in Cape Town were chosen to participate in this research. The data were collected using two rounds of in-depth semi-structured interviews. The interviews were transcribed and explicated using Giorgi’s phenomenological method. The findings show that although Physical Sciences educators are trying to support their learners, they are failing to meet the expectations of the learners. These findings provide new insights into understanding the world of the learner better and that the recommendations could have transformative implications for curriculum planners, curriculum advisors and pedagogical strategies in how the subject is presented to learners.

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Tam, Ka-lok Patrick, and 譚家樂. "A study of teachers' conceptions and teaching strategies in relation to students' alternative ideas about force and motion." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1994. http://hub.hku.hk/bib/B31957468.

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36

Montgomery, Neil James. "Analysis of superconducting thin films and their substrates using secondary ion mass spectrometry." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266425.

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37

Asp, Fredrik, and Leif Andersson. "New technology in physics : A study in how to integrate new technology and research in physics education in secondary high school." Thesis, Jönköping University, School of Education and Communication, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-1131.

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Youths do not reflect over how it works but rather focus on how they can use the technology. Earlier research has studied if teacher acquires further education in there topics, not if knowledge about new technology can contribute to a better education. If teachers have good knowledge about new technology and forwarding it to the pupils, can it increase the interest for physics among the pupils? Didactic research has shown that pupils would like to see conjunction with the knowledge they receives and their natural world. Didactic research concentrates on how knowledge is forwarding and not on the subject for the education. Six teachers on six different schools has been interview. On three of these schools has also five pupils been interview on their opinion on if and how new technology has be taken up in their education. New technology is being taken up in the physics education, but it exist no recommendation on how. New technologies are being taken up on the teacher’s initiative, paramountly for that rouse interest at pupils or connect the physics to the pupil's reality. Pupils receive also explanations of new technology when they put questions about it during lessons. The teacher’s apprehension about what is new technology varies. Common for all teachers is that they request better knowledge of their subjects of teaching for that being able to take up new technology with the pupils. They pupils that have interviewed thinks that it is good if new technology is being taken up in the physics education, it gives a better connection to reality.

Ungdomar reflekterar inte i första hand över hur ny teknik fungerar utan fokuserar på hur man kan använda tekniken. Tidigare forskning har studerat om lärare behöver ämnesfortbildning, inte om kunskap om ny teknik kan bidra till en bättre undervisning. Om läraren har god kunskap om ny teknik och förmedlar det till eleverna kan det då öka intresset för fysik hos eleverna? Didaktisk forskning har visat att elever vill se samband mellan den kunskap de får och deras omvärld. Didaktisk forskning inriktas på hur kunskap förmedlas och inte på ämnet i undervisningen. Sex lärare på sex olika skolor har intervjuats. På tre av dessa skolor har också fem elever intervjuats för att ge sin syn på om de anser att ny teknik tas upp i undervisningen. Studien visar på att ny teknik tas upp i fysikundervisningen, men det finns inga rekommendationer på hur. Ny teknik tas främst upp på lärarens initiativ, främst för att väcka intresse hos elever men också för att koppla fysiken till elevens verklighet. Elever får även förklaringar av ny teknik när de ställer frågor om den under lektioner. Lärares uppfattning om vad som är ny teknik varierar. Lärare efterfrågar bättre ämneskunskaper för att kunna ta upp ny teknik med eleverna. De elever som har intervjuats tycker det är bra om ny teknik tas upp i fysikkurserna, det ger en bättre koppling till verkligheten.

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38

Aziz, Nady Kamal. "Integration between mathematics and physics in secondary schools : an integrated mechanics unit for Egypt." Thesis, University College London (University of London), 1986. http://discovery.ucl.ac.uk/10019602/.

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39

Andersson, Jan. "Learning Physics Through Communication During Laboratory Work : An empirical study at upper secondary school." Doctoral thesis, Karlstads universitet, Institutionen för ingenjörsvetenskap och fysik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-48454.

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Laboratory work as a teaching and learning method is given prominence in the Swedish physics curriculum for upper secondary school. It is emphasised that students should be given opportunities to develop the ability to search for answers to questions, plan, conduct, interpret and present results. Moreover, students should also be encouraged to use their physics knowledge to communicate, argument and present conclusions. This thesis is based on the belief that physics laboratory work creates a special discourse, where the student becomes the actor and the teacher becomes the organiser and observer. Such an environment enables students to naturally engage in physics discussions using their own terms. The aim is to explore students’ laboratory work at upper secondary school in-depth, with respect to its design and influence on students’ communication. Through analysis of students’ communication, the purpose is to better understand the physics laboratory work’s possibilities as a teaching and learning method. This will contribute to ongoing debate about the effectiveness of laboratory work. The results show that laboratory work consists of similar activities but differs in amount of time allocated to the different activities. Different types of talk are used for different purposes. An analytical framework has been created to enable deeper investigations of how and what students are talking about at both a linguistic and cognitive level. Moreover, the analysis shows the importance of students acquiring knowledge about physics and understanding the value of using an investigative approach as well as acquiring core content physics knowledge.
Laboratory work as a teaching and learning method is given prominence in the Swedish physics curriculum for upper secondary school. It is emphasised that students should be given opportunities to develop the ability to search for answers to questions, plan, conduct, interpret and present results. Moreover, students should also be encouraged to use their physics knowledge to communicate, argument and present conclusions. This thesis is based on the belief that physics laboratory work creates a special discourse, where the student becomes the actor and the teacher becomes the organiser and observer. Through analysis of students’ communication, the purpose is to better understand the physics laboratory work’s possibilities as a teaching and learning method. The results show that laboratory work consists of similar activities but differs in amount of time allocated to the different activities. Different types of talk are used for different purposes. An analytical framework has been created to enable deeper investigations of how and what students are talking about at both a linguistic and cognitive level. Moreover, the analysis shows the importance of students acquiring knowledge about physics and understanding the value of using an investigative approach as well as acquiring core content physics knowledge.

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40

Eccles, Adrian John. "The design, construction and characterisation of a microfocused ion/atom gun for use in secondary ion mass spectrometry (SIMS)." Thesis, University of Manchester, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334868.

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41

Bouma, Craig Earl. "Physics First: Impact on SAT Math Scores." Digital Commons at Loyola Marymount University and Loyola Law School, 2013. https://digitalcommons.lmu.edu/etd/213.

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Improving science, technology, engineering, and mathematics (STEM) education has become a national priority and the call to modernize secondary science has been heard. A Physics First (PF) program with the curriculum sequence of physics, chemistry, and biology (PCB) driven by inquiry- and project-based learning offers a viable alternative to the traditional curricular sequence (BCP) and methods of teaching, but requires more empirical evidence. This study determined impact of a PF program (PF-PCB) on math achievement (SAT math scores) after the first two cohorts of students completed the PF-PCB program at Matteo Ricci High School (MRHS) and provided more quantitative data to inform the PF debate and advance secondary science education. Statistical analysis (ANCOVA) determined the influence of covariates and revealed that PF-PCB program had a significant (p < .05) impact on SAT math scores in the second cohort at MRHS. Statistically adjusted, the SAT math means for PF students were 21.4 points higher than their non-PF counterparts when controlling for prior math achievement (HSTP math), socioeconomic status (SES), and ethnicity/race.

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42

Bermudez, Julia V. "Examining the effects of physics second on high school science achievement." Thesis, California State University, Long Beach, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1527677.

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In 2007 Pioneer High School, a public school in Whittier, California changed the sequence of its science courses from the Traditional Biology-Chemistry-Physics (B-C-P) to Biology-Physics-Chemistry (B-P-C), or "Physics Second." The California Standards Tests (CSTs) scores in Physics and Chemistry from 2004-2012 were used to determine if there were any effects of the Physics Second sequencing on student achievement in those courses. The data was also used to determine whether the Physics Second sequence had an effect on performance in Physics and Chemistry based on gender.

Independent t tests and chi-square analysis of the data determined an improvement in student performance in Chemistry but not Physics. The 2x2 Factorial ANOVA analysis revealed that in Physics male students performed better on the CSTs than their female peers. In Chemistry, it was noted that male and female students performed equally well. Neither finding was a result ofthe change to the "Physics Second" sequencing.

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43

Toltz, Allison. "Prediction of risks of cardiac mortality and secondary cancers after thoracic radiotherapy in adolescents and young adults." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=110740.

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Intensity modulated proton therapy (IMPT) is believed to improve the therapeutic ratio by reducing the dose to normal tissue as compared to three dimensional conformal (photon) radiotherapy (3D-CRT). This hypothesis is investigated in this work by predicting the risks of late radiation-induced effects for young patients receiving radiotherapy for Hodgkin's and non-Hodgkin's lymphoma (HL and NHL) or breast cancer (BC) using radiobiological modeling. The late effects considered were cardiac mortality and secondary cancer in the lungs and breasts (for female patients).Patient data was acquired for twenty-eight patients who were under thirty years of age and were treated with radiotherapy for HL, NHL, or BC in Quebec in 2010. The original computed tomography simulation images were used to re-plan the patients with IMPT using Eclipse treatment planning software (version 10, Varian Medical Systems, Palo Alto, CA). The dose-volume data of the original photon plans and the new proton plans were analyzed using the relative seriality model to assess the risks of late effects. The relative seriality model was utilized to predict excess risk of cardiac mortality. The Schneider1 modified linear quadratic model was used to predict the excess absolute risk for induction of lung cancer and breast cancer. Parameters for each model were derived from retrospective studies in the literature.Dosimetric plan comparison revealed IMPT reduced dose to the organs at risk of interest as compared to 3D-CRT. Overall the excess risk of cardiac mortality and the excess absolute risks for lung and breast cancers were reduced for IMPT as compared to 3D-CRT.
La radiothérapie par modulation d'intensité de protons (IMPT) améliore le ratio thérapeutique en réduisant la dose délivrée aux tissus sains, par rapport à la radiothérapie conformationelle trois dimensions par photons (3D-CRT). L'objectif de cet étude est de confirmer cette hypothèse dans ces deux modalités de traitement par une comparaison de de risque prédictible d'effets secondaires à long terme dû aux rayonnements ionisants pour des jeunes patients traités par radiothérapie pour des lymphomes Hodgkiniens et non-Hodgkiniens (HL et NHL) ou pour un cancer du sein (BC) à l'aide des modèles radiobiologiques. Les effets secondaire à long terme étudiés sont la mortalité cardiaque et les cancers secondaires du poumon ou du sein (pour les patientes).Les données de vingt-huit patients de moins de trente ans ayant été traités par radiothérapie pour HL, NHL, ou BC au Québec en 2010 ont été collectées. Les images original de tomodensitomètres ont été utilisées pour re-plannifier les patients avec l'IMPT à l'aide du logiciel de planification de traitement Eclipse (version 10, Varian Medical Systems, Palo Alto, CA). Les données des histogrammes dose-volume du plan original en photon ainsi que la replanification en proton ont été analysées pour évaluer les risques d'effet secondaires à long terme. Le modèle de sérialité relative1, a été utilisé pour prédire le risque excessif de mortalité cardiaque. Le model linéaire quadratique modifié de Schneider2 a été utilisé afin de prédire l'excès absolu de risque de cancer du poumon et du sein. Les paramètres de chaque modèles ont été dérivés d'études rétrospectives tirées de la littérature.La comparaison dosimétrique des plans a démontré que l'IMPT réduit la dose délivrée aux organes à risque par rapport à la 3D-CRT. En général, le risque excessif de mortalité cardiaque et l'excès absolu de risque de cancer du poumon et du sein sont réduits avec l'IMPT par rapport à la 3D-CRT.

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44

Shin, Naomi. "Modeling secondary cancer risk following paediatric radiotherapy: a comparison of intensity modulated proton therapy and photon therapy." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=106431.

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Proton radiotherapy is known to reduce the radiation dose delivered to normal healthy tissue compared to photon techniques. The increase in normal tissue sparing could result in fewer acute and late effects from radiation therapy. In this work proton therapy plans were created for patients previously treated using photon therapy. Intensity modulated proton therapy (IMPT) plans were planned using inverse planning in Varian's Eclipse treatment planning system with a scanning proton beam model to the same relative biological effectiveness (RBE)-weighted prescription dose as the photon plan. Proton and photon plans were compared for target dose conformity and homogeneity, body volumes receiving 2 Gy and 5 Gy, integral dose, dose to normal tissues and second cancer risk. Secondary cancer risk was determined using two methods. The relative risk of secondary cancer was found using the method described by Nguyen et al. by applying a linear relationship between integral dose and relative risk of secondary cancer. The second approach used Schneider et al.'s organ equivalent dose concept to describe the dose in the body and then calculate the excess absolute risk and cumulative risk for solid cancers in the body.IMPT and photon plans had similar target conformity and homogeneity. However IMPT plans had reduced integral dose and volumes of the body receiving low dose. Overall the risk of radiation induced secondary cancer was lower for IMPT plans compared to the corresponding photon plans with a reduction of ~36% using the integral dose model and ~50% using the organ equivalent dose model.
Un avantage connu de la radiothérapie par protons est la réduction de la dose reçue par les tissus normaux et sains par rapport aux traitements en photons. Cette réduction de dose peut résulter en une diminution des effets aigus et tardifs de la radiothérapie. Dans cet ouvrage, les plans de protonthérapie ont été créés pour des patients ayant été traités par radiothérapie en photons. Les plans de protonthérapie conformationnelle avec modulation d'intensité (PCMI) ont été conçus par planification inverse dans le système de planification de traitement Eclipse de Varian de façon à ce que le faisceau de protons en balayage produise la même dose de prescription que plan en photons, tout en tenant compte des efficacités biologiques relatives des deux types de radiation. Les plans en photons et en protons ont ensuite été comparés en termes de conformité de la dose, d'homogénéité de la dose, de volumes recevant 2 et 5 Gy, de dose intégrale, de dose aux tissus normaux et de risque de cancer secondaire. Le risque relatif de cancer secondaire a été determiné par la méthode décrite par Nguyen et al. en applicant une relation linéaire entre la dose intégrale et le risque relatif de cancer secondaire. Une deuxième approche employée dans cet ouvrage utilise le concept de dose équivalente à un organe de Schneider et al. pour décrire la dose dans le corps et par la suite calculer l'excès de risque absolu et le risque cumulatif de cancers solides dans le corps. Les traitements comparés, soit en photons et en protons, ont démontré une conformité et une homogénéité de la dose similaires dans le volume cible. Toutefois, les plans de PCMI réduisent la dose intégrale et diminuent les volumes du corps recevant une faible dose. Globalement, le risque d'induction d'un cancer secondaire est plus faible pour les plans de PCMI que pour les plans équivalents en photons avec une réduction de ~36% en utilisant le modèle de dose intégrale et ~50% en utilisant le modèle de dose équivalente à un organe.

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45

Ng, Sui-kou. "Microcomputer and physics : a study of the effectiveness of computer assisted learning as an aid on students' understanding of the concepts of force and motion in secondary school physics /." Hong Kong : University of Hong Kong, 1988. http://sunzi.lib.hku.hk/hkuto/record.jsp?B18039364.

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46

Walton, Scott Gregory. "The role of adsorbed oxygen in secondary emission from metallic substrates." W&M ScholarWorks, 1998. https://scholarworks.wm.edu/etd/1539623943.

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Low energy, ion- and photon-induced secondary electron and anion emission from metallic substrates has been investigated as a function of adsorbate coverage. Sodium positive ions (Na+), with kinetic energies up to 500 eV, and photons, with energies up to 23 eV, are utilized to initiate secondary emission. The principal adsorbate is oxygen with coverages ranging from none to a few monolayers.;For ion-induced emission, the secondary electron and negative ion absolute and relative yields from 302 stainless steel and polycrystalline tungsten (W) have been measured as a function of both impact energy and oxygen coverage. Additionally, the yields from a "technical" stainless steel surface, i.e., a surface for which no in-situ cleaning is performed, have been measured. The sputtered anions have been identified by secondary ion mass spectroscopy (SIMS). For both surfaces, adsorbate coverage is found to greatly enhance the electron and anion yields at all impact energies.;In addition, the kinetic energies of the secondary electrons and negative ions have been measured as a function of both impact energy and oxygen coverage. The electron and anion kinetic energy distributions exhibit low most probable energies (1--2 eV) and unique features that are substrate dependent.;Photoelectron kinetic energy distributions for aluminum (Al), molybdenum (Mo), Mo (100) and stainless steel have been measured, as a function of oxygen coverage, in order to ascertain the effects of adsorbed oxygen. Additionally, photon-stimulated anion desorption from oxygen covered Al has been measured as a function of photon energy. This anion desorption is found to have a narrow resonance at approximately 8.75 eV.;The resonance in the photon-induced anion emission is shown to be in direct support of a model proposed to explain the observed ion-induced secondary electron and O- emission from an oxygen covered Al surface. The model invokes a collision-induced excitation, of a surface state, that serves as a precursor to both electron and anion emission. This model is discussed in detail and utilized to explain the emission from oxygen covered stainless steel and tungsten. The results for the technical stainless steel surface are related to those for the oxygen covered surface and the implications for plasma discharge modeling are discussed.

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47

Nagpure, Bhupendra Singh. "The Effects of Reasoning about Vector Components on Student Understanding of Two-Dimensional Acceleration." Fogler Library, University of Maine, 2008. http://www.library.umaine.edu/theses/pdf/NagpureBS2008.pdf.

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48

Dixon, Charles Harwood. "The evaluation of qualitative examination questions at matriculation level in physics." Thesis, Rhodes University, 1990. http://hdl.handle.net/10962/d1001439.

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The style and format of Physics examination papers has changed markedly over the past hundred years. Physics was regarded formerly as a sub-division of Mathematics; hence, apart from giving formal statements of scientific laws, and some account of experimental procedures, examination candidates were required to spend most of their time, and to earn most of their marks by solving numerical problems. Most Physics examination papers today retain the emphasis on problem-solving by calculation. It has been recognised, however, that the ability to obtain correct numerical answers by substition in a formula does not necessarily imply understanding of the physical principles which underly the problem. There has been a reaction against the awarding of marks for algebraic or arithmetical manipulation. Bloom and his disciples, by calling on examiners to define precise behavioural objectives, have encouraged the development of qualitative questions. These require no calculation nor numerical answer, but do aim to test the candidate's insight, by requiring him either to explain phenomena in scientific terms, or to predict the outcome of changing conditions. In this investigation samples of both quantitative and qualitative questions were extracted from Physics papers past and present. A closer study was made of qualitative questions used in the Natal Senior Certificate Physics papers (both Higher Grade and Standard Grade) in November 1987. The examiners were asked to state the objective of each question, as well as its categorization in terms of a simplified Bloom taxonomy. Candidates' answers to these questions were extracted from the scripts written at a representative sample of Natal schools. In the case of multiple-choice questions, an item analysis was performed, and discrimination indices were calculated . The responses of individual candidates to the longer questions were collected, classified and discussed. In each case the effectiveness of the question was studied, as to whether or not it was successful in detecting the presence of correct scientific concepts in the candidates' thinking. It was concluded that most of the qualitative questions used by the examiners were effective. Suggestions were made as to how their efficacy could be improved. Much further study and experimentation are needed to develop the effective use of this type of question

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Liu, Tsunglin. "Physics and bioinformatics of RNA." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1141407392.

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50

Lawrence, Paula Tracki. "Developing a Laboratory Curriculum for Physics I." UNF Digital Commons, 1986. http://digitalcommons.unf.edu/etd/58.

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Abstract:

This curriculum project reviews the current research on laboratory activity formats and their effectiveness. The literature concerning laboratory safety and teacher liability is also reviewed. The revision of Florida state high school science requirements is presented and the curriculum developed corresponds to these revisions. The project includes laboratory activities that correspond to the course student performance standards as designated by the state of Florida for the Physics I course and strives to aid teachers in fulfilling the 72 hour laboratory time requirement to meet eligibility requirements for additional state funding. The criteria for selecting activities and materials are also included in this project. A sample evaluation form is included, as well as a summary of these teacher evaluations of the developed curriculum.

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Dissertations / Theses on the topic 'Secondary Physics'

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