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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A time series study of Rigel, a B8Ia supergiant

Rother, Sara 23 September 2009 (has links)
No description available.
2

An Assessment of Retractions as a Measure of Scientific Misconduct and Impact on Public Health Risks

Abritis, Alison J. 01 January 2015 (has links)
Research misconduct has been generally considered a limited issue, occurring in a small percentage of research studies. Studies of the number of article retractions use retraction percentages to perpetuate the idea that research misconduct is not a common event, and use information in the retraction notice to quantify types of research misconduct and types or research error. However, retractions appear to be the wrong variable with which to assess misconduct rates and characteristics. Using final misconduct findings in hard science research from the Office of Research Integrity (ORI) for investigations closed from 1993 through 2013, the number of publications and subsequent retractions or corrections per final ORI finding was analyzed. Out of 167 subjects who received ORI sanctions, 84 (50.3%) had no publications associated with their misconduct. Of the remaining 83 subjects, only 72 had at least one retraction associated with their misconduct, i.e., only 43.1% of the all study subjects sanctioned for misconduct had at least one retraction from misconduct. Of the 231 retractions and corrections arising from the sanctioned misconduct, only 94 notices (40.6%) gave research misconduct as a cause for the retraction or correction. Thus, the study demonstrates that research misconduct occurs at a greater rate than retractions for misconduct are published, and retraction and correction notices cannot be relied upon to convey the presence of fraudulent data within the publication.
3

Cult Buildings In Aceramic Neolithic Southeast Anatolia: A Case Study Of Nevali Cori

Sentek, Mina 01 April 2006 (has links) (PDF)
First settlements in Southeast Anatolia begun to appear as early as 10000 BC. Among all the unanswered questions about this early period, cult-related activities and cult buildings are widely studied due to their nature, which has strong connections with the social organization and early symbolism. During the last decade, Southeast Anatolia has provided new evidence for this early stage of development in human history. This study aims to examine cult buildings that have common characteristics / how they were treated and distributed. The settlement of Nevali &Ccedil / ori and its cult building is taken as an example and studied in detail. Other cult buildings with the same or similar architectural features are included in this study in order to discuss the roots, the distribution and the continuity of this Aceramic Neolithic tradition.
4

Non-local Finite Element Model for Rigid Origami

January 2014 (has links)
abstract: Origami is an art transforming a flat sheet of paper into a sculpture. Among various types of origami, the focus is on a particular class called the `Rigid Origami' ("RO"). A Rigid Origami, unlike other forms, is not intended to be folded into fancy shapes. On the contrary, an RO has a simple and a geometrically well-defined crease pattern and does not have curved/smudged faces. The folds can be carried out by a continuous motion in which, at each step, each face of the origami is completely flat. As a result, these planar faces experience very minimal strain due to loading. This property allows it to be used to fold surfaces made of rigid materials. Tapping into the geometrical properties of RO will open a new field of research with great practical utility. Analyzing each new RO pattern will require generating numerous prototypes; this is practically impossible to do, as it consumes a lot of time and material. The advantages of Finite Element Analysis/numerical modeling become very clear in this scenario. A new design concept may be modeled to determine its real world behavior under various load environments and may, therefore, be refined prior to the creation of drawings, when changes are inexpensive. Since an RO undergoes a non-local deformation when subjected to a disturbance, the usage of conventional FEA will not produce accurate results. A non-local element model was developed which can be used in conjunction with the finite element package ABAQUS, via its user-defined element (UEL). This model was tested on two RO patterns, namely Miura-Ori and Ron Resch, by carrying out basic simulations. There are many other interesting origami patterns, exhibiting different meta-material properties, yet to be explored. This Finite Element Approach equips researchers with necessary tools to study those options in great detail. / Dissertation/Thesis / M.S. Mechanical Engineering 2014
5

Elastic Energy Absorption via Compliant Corrugations

Tolman, Sean S. 01 July 2014 (has links) (PDF)
Elastic absorption of kinetic energy and distribution of impact forces are required in many applications. This may be achieved through the use of compliant corrugations. An innovative padding concept is investigated for such applications. Also, recent attention given to the potential for using origami in engineering applications may provide new corrugation configurations that are advantageous for energy absorption and force distribution. This work explores three areas related to these concepts.First, the parameters of a compliant, corrugated padding concept are investigated using Finite Element Analyses (FEA) and physical testing. The shape of the corrugation cross section is explored as well as the wavelength and amplitude by employing a full factorial design of experiments. FEA results are used to choose designs for prototyping and physical testing. The results of the physical testing were consistent with the FEA predictions although the FEA tended to underestimate the peak pressure compared to the physical tests. A performance metric is proposed to compare different padding configurations. The concept shows promise for sports padding applications. It may allow for designs which are smaller, more lightweight, and move better with an athlete than current technologies yet still provide the necessary protective functions.Second, the elastic energy absorbing properties of a particular origami folding pattern, the Miura-ori, is investigated. Analytical models for the kinematics and force-deflection of a unit cell based on two different modes of elastic energy absorption are derived. The models are used to explore the effects of the key geometrical parameters of the tessellation. Physical prototypes are compared to the analytical models.Third, a three-stage strategy is presented for selecting materials for origami-inspired corrugations that can deform to achieve a desired motion without yielding, absorb elastic strain energy, and be light weight or cost effective. Two material indices are derived to meet these requirements based on compliant mechanism theory. Using Finite element analysis, it is shown that the properties of Miura-ori pattern has advantages for energy absorption and force distribution when compared to a triangular wave corrugation. While the focus of these studies is the Miura-ori tessellation, the methods developed can be applied to other tessellated patterns used in energy absorbing or force distribution applications.
6

Selecting and Optimizing Origami-Based Patterns for Deployable Space Systems

Bolanos, Diana Stefania 19 July 2022 (has links)
This thesis addresses the design difficulties encountered when designing deployable origami-based arrays. Specific considerations regarding thickness accommodation, deployment, and parameter modifications are discussed. Patterns such as the Miura-ori, flasher, and hexagon are investigated, with emphasis placed on pattern modification from zero-thickness to finite-thickness. Applying origami principles to form engineering solutions is a complicated task. Competing requirements may create confusion around which pattern is most favorable for the space array application. Implementing origami into a finite-thickness, engineered system poses challenges that are not manifest in a zero-thickness model. As such, it is important to understand and address the limitations of the pattern before implementing it into an engineered system. A preliminary set of approaches to address and mitigate design difficulties is provided. This thesis seeks to improve understanding of design parameters, objectives, and trade offs of origami pattern configurations. Emphasis is placed on finite-thickness models suitable for engineering applications. As a result, engineers and designers should be better prepared to integrate origami principles into space system design.
7

A Coordinated X-ray and Optical Campaign of the Nearest Massive Eclipsing Binary, δ Orionis Aa. III. Analysis of Optical Photometric (MOST) and Spectroscopic (Ground Based) Variations.

Pablo, Herbert, Richardson, Noel, Moffat, Anthony, Corcoran, Michael, Shenar, Tomer, Benvenuto, Omar, Fuller, Jim, Nazé, Yaël, Hoffman, Jennifer, Miroshnichenko, Anatoly, Apellániz, Jesús, Evans, Nancy, Eversberg, Thomas, Gayley, Ken, Gull, Ted, Hamaguchi, Kenji, Hamann, Wolf-Rainer, Henrichs, Huib, Hole, Tabetha, Ignace, Richard, Iping, Rosina, Lauer, Jennifer, Leutenegger, Maurice, Lomax, Jamie, Nichols, Joy, Oskinova, Lida, Owocki, Stan, Pollock, Andy, Russell, Christopher, Waldron, Wayne, Buil, Christian, Garrel, Thierry, Graham, Keith, Heathcote, Bernard, Lemoult, Thierry, Li, Dong, Mauclaire, Benjamin, Potter, Mike, Ribeiro, Jose, Matthews, Jaymie, Cameron, Chris, Guenther, David, Kuschnig, Rainer, Rowe, Jason, Rucinski, Slavek, Sasselov, Dimitar, Weiss, Werner 18 August 2015 (has links) (PDF)
We report on both high-precision photometry from the Microvariability and Oscillations of Stars (MOST) space telescope and ground-based spectroscopy of the triple system δ Ori A, consisting of a binary O9.5II+early-B(Aa1 and Aa2) with P=5.7 days, and a more distant tertiary(O9 IV P 400 years). This data was collected in concert with X-ray spectroscopy from the Chandra X-ray Observatory. Thanks to continuous coverage for three weeks, the MOST light curve reveals clear eclipses between Aa1 and Aa2 for the first time in non-phased data. From the spectroscopy, we have a well-constrained radial velocity (RV)curve of Aa1. While we are unable to recover RV variations of the secondary star, we are able to constrain several fundamental parameters of this system and determine an approximate mass of the primary using apsidal motion. We also detected second order modulations at 12 separate frequencies with spacings indicative of tidally influenced oscillations. These spacings have never been seen in a massive binary, making this system one of only a handful of such binaries that show evidence for tidally induced pulsations.
8

Känner mig inte mer annorlunda än någon annan i Sverige : Ensamkommande barns integrationsprocess i Sverige

Kareme, Karwan, Mahdi, Saif January 2015 (has links)
Syftet med denna undersökning var att bidra till en ökad kunskap kring ensamkommande flyktingbarns integrationsprocess i det svenska samhället. Vidare syftar studien till HVB-hemmets roll i denna process. Studiens val av metod är den kvalitativa metoden med åtta öppna intervjuer. Vi använde teorier som berör integrationsprocessen, vilket i detta fall var identitet, roll, socialt nätverk, socialt stöd, integration samt byråkrati för verksamhetens arbete. Studiens resultat tyder på att HVB-hemmets roll för denna process har varit omfattande med tanke på boendet har bidragit till att skapa ett tryggt hem, erbjudit socialt stöd, uppmuntrat till att delta i föreningslivet samt bidragit till sociala kunskaper. Även språket, skolan, nätverket och stödet från myndighetsutövare har bidragit till integrationsprocessen för barnen. Slutsatser som framkom är att de före detta ensamkommande asylsökande barnen är på ett objektivt och subjektiv plan integrerade i det svenska samhället. Lyckade integrationsprocesserna beror på kombinationen mellan barnens egna drivkrafter och samhället tillgängliga stödfunktioner. I och med flykten till ett främmande land kan en slutsats dras från denna studie att rollförändringar och identitetsbildningar har präglat de före detta ensamkommande barnen under deras integrationsprocess. Även inslag av rollförändringar och identitetsskapande finns hos personalen som arbetat med de ensamkommande barnen genom samspelet mellan grupperna. / The purpose of this study was to contribute to an increased knowledge of unaccompanied refugee children's process of integration into the Swedish society. Furthermore, the study aims to HVB-home role in this process. The study selection method is the qualitative method with eight open interviews. We used the theories related to the integration process, which in this case was the identity, role, social networks, social support and integration. Also bureaucracy was used to describe HVB-homes work. The study's results suggest that HVB-home role in this process has been extensive considering the accommodation has helped to create a safe home, offering social support, encouraged to participate in club activities and contributed to social skills. Even the language, school, network and the support of public power have contributed to the integration process for children. Conclusions that emerged is that the former unaccompanied asylum seeking children are in an objective and subjective planes integrated into the Swedish society. Successful integration processes depends on the combination of the children's own motivations and society accessible support functions. By fleeing to a foreign country, there is a role change and identity formation that characterized the former unaccompanied children during their integration process. Elements of the role and identity changes characterize the staff worked with this group through collaboration between the groups.
9

A Coordinated X-ray and Optical Campaign of the Nearest Massive Eclipsing Binary, δ Ori Aa: I. Overview of the X-ray Spectrum.

Corcoran, Michael, Nichols, Joy, Pablo, H., Shenar, Tomer, Pollock, Andy, Waldron, W., Moffat, A., Richardson, N., Russell, C., Hamaguchi, K., Huenemoerder, D., Oskinova, L., Hamann, W.-R., Nazé, Y., Ignace, Richard, Evans, Nancy, Lomax, Jamie, Hoffman, J., Gayley, K., Owocki, S., Leutenegger, M., Gull, T., Hole, K., Lauer, J., Iping, R. 18 August 2015 (has links) (PDF)
We present an overview of four deep phase-constrained Chandra HETGS X-ray observations of δ Ori A. Delta Ori A is actually a triple system that includes the nearest massive eclipsing spectroscopic binary, δ Ori Aa, the only such object that can be observed with little phase-smearing with the Chandra gratings. Since the fainter star, δ Ori Aa2, has a much lower X-ray luminosity than the brighter primary (δ Ori Aa1), δ Ori Aa provides a unique system with which to test the spatial distribution of the X-ray emitting gas around δ Ori Aa1 via occultation by the photosphere of, and wind cavity around, the X-ray dark secondary. Here we discuss the X-ray spectrum and X-ray line profiles for the combined observation, having an exposure time of nearly 500 ks and covering nearly the entire binary orbit. The companion papers discuss the X-ray variability seen in the Chandra spectra, present new space-based photometry and ground-based radial velocities obtained simultaneously with the X-ray data to better constrain the system parameters, and model the effects of X-rays on the optical and UV spectra. We find that the X-ray emission is dominated by embedded wind shock emission from star Aa1, with little contribution from the tertiary star Ab or the shocked gas produced by the collision of the wind of Aa1 against the surface of Aa2. We find a similar temperature distribution to previous X-ray spectrum analyses. We also show that the line half-widths are about 0.3−0.5 times the terminal velocity of the wind of star Aa1. We find a strong anti-correlation between line widths and the line excitation energy, which suggests that longer-wavelength, lower-temperature lines form farther out in the wind. Our analysis also indicates that the ratio of the intensities of the strong and weak lines of Fe XVII and Ne X are inconsistent with model predictions, which may be an effect of resonance scattering.
10

En gate / A street

Aasgaard, Peter Wilhelm Valerius January 2018 (has links)
Kort beskrivelse av prosjektet: Oppgaven har vært å tegne et samlingshus for et antall omgivende videregående skoler. Ved å sentralisere ulike funksjoner som bibliotek, sosiale arealer og matsal fungerer huset som et felles læresenter for elevene.  I en tidlig fase fant jeg ut at jeg ville fokusere på å gjøre huset tilgjengelig for offentligheten slik at det ikke blir stående tomt utenom skoletidene. Dette ville jeg uttrykke både i form og i tolking av programmet. Så hvordan viser man at en bygning er åpen for alle i form? Jeg valgte å ta inspirasjon fra det mest offentlige jeg kjenner til, nemlig det offentlige rommet. Det jeg anser som spesielt med dette er at rommet bare fortsetter og fortsetter og består ikke av stengte vegger som man ofte finner i konvensjonelle bygninger. Ved å la gulvet være sammenhengende gjennom hele huset oppnås et interiør som jeg tror kan oppfattes som et offentlig rom. Jeg forsterket denne opplevelsen ved å koble gulvet til fjellet som grenser til tomten og huset ble dermed en offentlig vei per definisjon.  Hvordan fungerer interiøret? En utfordring har vært å definere rom når konseptet er at det skal være helt åpent. Derfor har jeg valgt ut fire parametere for å definere funksjonene: Møbler, et flatt gulv, dobbel takhøyde og til slutt det stengte rommet (se diagram, romdefineringer, s. 5). Hvilken rolle spiller programmet i konseptet? Flere av funksjonene i programmet var hva man ofte tenker på som soner kun for ansatte, som for eksempel administrasjon, rengjøring og kjøkken Jeg valgte å utfordre denne ideen og gjøre det slik at disse funksjonene ble tilgjengelige for folk flest. Gjennom et internt bookingsystem kan selv de som ikke er elever anvende huset og dets muligheter. For eksempel kan man booke, utenom skoletider, kjøkkenet for å lage mat i større volumer, black boxen for å holde en forestilling, et singelrom som kontor, et konferanserom for lesesirkelen på søndager, det multifunksjonelle torget for en bryllupsfest, osv. Hva oppnår man ved å koble huset med Enskede Gård? I planprogrammet står det: ”Stockholms ytterstad har till stor del vuxit fram etappvis och resulterat i stadsdelar som sinsemellan skiljer sig åt, men som i sig själva har ett homogent bostadsbestånd med likartade typologier och prisnivåer. (...) Slakthusområdet, som är tänkt att omvandlas under drygt ett decennium, är en del av denna utveckling. (...) En mer differentierad prisbild och lägre hyresnivåer finns att hitta i det befintliga beståndet, vilket gäller både bostäder och lokaler. Därför spelar programmets ambition att koppla samman Slakthusområdet med omkringliggande stadsdelar en viktig roll i att minska den geografiska segregationen mellan de olika områdena och skapa en funktionell helhet av dagens separata delar”. Utover dette ligger Lindeparken gymnasiesärskola i området og kan med grepet ta del av læresenterets tilbud.  Materialer? Ved å bruke materialer som ofte forekommer i et byrom kan følelsen av et offentlig og åpent rom forsterkes. I huset forekommer derfor stein, asfalt, betong, glass og stål. I tillegg har jeg fokusert på å la grensen mellom ute og inne defineres kun med glass samtidig som den dras inn ved den offentlige veien. Utover dette har jeg latt de rommene som er stengte få en varmere karakter, slik at de blir som små hus man går inn i, fra gaten. / Project description: Three planned high schools in the area were to have a common building with different social functions, such as a library, social areas and a dining room.  Early on in the process, I figured that the program had many functions that potensially could be interesting for the general public, such as a library, social areas and an exhibition. This led to the concept of opening up the building and making it accessible to everyone, creating potensial for an active building, even after school hours.  So how can openness be communicated in form? My concept was to extend the public space and let it continue uninterrupted through the whole interior., in short: a ramp. By connecting the ramp to Enskede, lying ten metres above the plot, the building became a public street. Stockholm municipality had an ambition for opening up Slakthusomradet, and the building became a part of this project. The program in the assignment excisted of many zones, usually associated with staff areas. I wanted to change that conception and make these rooms open to the public. These rooms included for example administration, cleaning and kitchen.  The materials used were all taken from typical public spaces, such as concrete, stone, asphalt, steel and glass. Furthermore, the character of the materials were to change when you moved from “the street” and into the closed spaces. Here you would find wooden walls and furniture, as well as curtains of cotton.

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