Um die anderen Arten von Veröffentlichungen zu diesem Thema anzuzeigen, folgen Sie diesem Link: Screen types.
Dissertationen zum Thema „Screen types“
Geben Sie eine Quelle nach APA, MLA, Chicago, Harvard und anderen Zitierweisen an
Machen Sie sich mit Top-50 Dissertationen für die Forschung zum Thema "Screen types" bekannt.
Neben jedem Werk im Literaturverzeichnis ist die Option "Zur Bibliographie hinzufügen" verfügbar. Nutzen Sie sie, wird Ihre bibliographische Angabe des gewählten Werkes nach der nötigen Zitierweise (APA, MLA, Harvard, Chicago, Vancouver usw.) automatisch gestaltet.
Sie können auch den vollen Text der wissenschaftlichen Publikation im PDF-Format herunterladen und eine Online-Annotation der Arbeit lesen, wenn die relevanten Parameter in den Metadaten verfügbar sind.
Sehen Sie die Dissertationen für verschiedene Spezialgebieten durch und erstellen Sie Ihre Bibliographie auf korrekte Weise.
1
Lundin-Emanuelsson, Madeleine. „Screen time and Mental health problems : A population-based study [SALVe] about screen time contribution to mental health problems among adolescents in Västmanland“. Thesis, Mälardalens högskola, Hälsa och välfärd, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-55158.
Der volle Inhalt der QuelleAnnotation:
There is an increasing trend of mental health problems both globally and in Sweden. Moreover, in recent decades there has been an increase in screen time among adolescents. The present study aimed to examine the associations between screen time (i.e., smartphone, computer, and TV) and mental health problems among adolescents in Västmanland and to investigate if the association was different due to gender. A quantitative method with a cross-sectional design was applied. The study used secondary data from the Survey of Adolescent Life in Västmanland 2020. The sample consisted of 3880 adolescents from 9th grade in compulsory school and 2nd grade in upper secondary school. The results showed that high screen time on smartphone was associated with an increased probability for mental health problems in the total sample. In contrast, screen time on TV and computer showed no significant association with mental health problems. Thus, smartphone use was a significant contributor to mental health problems. Furthermore, for girls, high screen time on the smartphone, computer, and TV was associated with increased probability of mental health problems, whereas no significant associations were found among boys. In brief, this study’s findings suggest developing Swedish guidelines to regulate harmful effects from screen time.
2
Botello, Jennifer A. „Comparing the Effect of Two Types of Computer Screen Background Lighting on Students' Reading Engagement and Achievement“. Thesis, Lindenwood University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3618650.
Der volle Inhalt der QuelleAnnotation:
With increased dependence on computer-based standardized tests to assess academic achievement, technological literacy has become an essential skill. Yet, because students have unequal access to technology, they may not have equal opportunities to perform well on these computer-based tests.
The researcher had observed students taking the STAR Reading test (Renaissance Learning, 2009) and noticed a variance in scores in relation to classroom performance. The researcher intended, therefore, to explore variables that may affect the performance of students on a computer-based reading assessment. The researcher tested two different technology-related variables as students took a summative exam, the STAR Reading test. The purpose of this study was to explore how changes in visual stimuli affected the process of reading and student reading behavior. This quantitative study sought to ascertain whether changing the computer read-out to a black screen with white lettering made a difference in student engagement and comprehension among students in grades two through six during a computer-based adaptive test.
The research site was one K-6 elementary school in a large suburban school district. The participants of the study were 316 children in grades two through six. One hundred and sixteen students were randomly sampled for student engagement data analysis. The researcher conducted a stratified random process to further select data for analysis. Students were exposed to both color display background variables throughout the study process. Teacher observers collected tallies on student engagement behaviors during the test-taking process.
The researcher calculated the mean level of student engagement on each of five observed behaviors. The researcher also collected reading comprehension data for five subsequent benchmark sessions throughout the year. The engagement results of this study failed to support the hypothesis, which stated that elementary student behaviors during testing would verify a measureable difference in engagement when either a black or white display screen was presented. The results of the reading comprehension test also failed to support the hypothesis, which stated that there would be a measureable difference in elementary students' scores while taking computer-based tests when the computer screen was set to either black or white background.
3
Lapeine, David. „Etude et optimisation de nouveaux types de capteurs pour la détection de polluants en milieu aquatique“. Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT256/document.
Der volle Inhalt der QuelleAnnotation:
Dans cette thèse, nous présentons l’étude et la réalisation de micro-capteurs pour les systèmes de gestion des risques naturels. Le cahier des charges était centré sur les possibilités de concevoir des capteurs de polluants pour la surveillance des zones lagunaires dans le sud montpelliérain. Ces capteurs devaient être conçus dans une démarche « faible coût », résistant aux contraintes du milieu et pouvant communiquer et temps réel. Le premier chapitre s’appuie sur une étude bibliographique des différentes méthodes de mesures qui peuvent être utilisées pour faire de la détection de polluants et des matériaux potentiels pour réaliser le capteur. La technique de mesure la plus appropriée pour répondre aux deux premiers points du cahier des charges s’appuie sur la réalisation de transducteurs acoustiques à base de PZT en envisageant un processus technologique basé sur la technique de sérigraphie. Après avoir justifié notre choix de la technique de dépôt par sérigraphie, nous avons détaillé dans le second chapitre le processus technologique, en commençant par la réalisation de l’encre PZT, puis par le dessin des masques et pour finir nous avons détaillé les étapes de dépôt et de fonctionnalisation des transducteurs sur substrat d’alumine et sans substrat. A partir de ces premières réalisations, nous avons présenté les moyens et outils de caractérisation nécessaires pour pouvoir évaluer les différentes étapes du processus technologique mis en place, avec une attention particulière portée sur la qualité du matériau PZT et sur ses propriétés piézoélectriques. Il s’agit d’une part d’études morphologiques (images MEB, profilomètre) et structurelles (diffraction X, EDX) et d’autre part de la mesure des grandeurs piézoélectriques et diélectriques (piézomètre, analyses spectrales et d’impédances). Dans le troisième chapitre nous avons abordé le volet système de cette étude, avec la réalisation de prototypes basés sur les transducteurs sérigraphiés développés au chapitre 2. Les capteurs réalisés ont été testés et étalonnés avec des solutions d’éthanol et de toluène. Pour cela les capteurs sérigraphiés ont été testés sur des bancs expérimentaux afin de valider la technique de la mesure du temps de vol des ondes acoustiques. Dans l’optique de la miniaturisation et de l’intégration du système nous avons mis en place une électronique de commande embarquée à l’aide d’un module dédié. Enfin, pour pouvoir affiner les mesures, nous avons vu que nous pouvions envisager de croiser/corréler plusieurs paramètres. C’est ainsi que nous avons développé un capteur sérigraphié pour la mesure de la conductivité électrique en milieu aquatique. A partir des premiers résultats expérimentaux obtenus nous avons pu valider le principe de la méthode. Dans le quatrième et dernier chapitre de ce manuscrit, nous avons présenté les toutes premières études et réalisations sur la technologie LTCC. En reprenant les paramètres du processus utilisés lors des dépôts sur substrat d’alumine, nous avons réalisé et caractérisé des transducteurs déposés sur une feuille de céramique LTCC. Les premières caractérisations morphologiques et piézoélectriques sont encourageantes et les premiers tests acoustiques ont montré que la génération d’ondes acoustiques était tout à fait possible et qu’une utilisation en vue de la réalisation de capteurs de polluants était envisageable avec cette technologie. Enfin, nous avons pu réaliser une première structure 3D intégrant une cavité d’analyse. Là encore les débuts sont très prometteurs même s’il reste encore beaucoup de travail de « réglage » pour améliorer cette technologie. De plus, cette première réalisation 3D, ouvre de nombreuses perspectives au niveau de l’équipe en vue du développement de nouveaux capteursIn this thesis, we introduce the study and implementation of micro-sensors for natural risk management systems. The specification focused on the possibilities to develop a pollutant sensor capable of detecting the presence of hydrocarbons in the lagoon environments of southern Montpellier.These sensors should be designed in a "low cost" gait, resistant to environmental constraints and able to communicate in real time. The first chapter is based on a bibliographical study of the different methods of measurement that can be used for the detection of pollutants and potential materials for making the sensor. The most suitable measurement technology to answer the first two points of the specification is based on the implementation of acoustic transducers made from PZT with a technological process using the screen-printing technique. After justifying our choice of screen-printing deposition technique, we have detailed in the second chapter the technological process: first with the achievement of PZT ink, then with the masks design, and finally with the steps deposition and functionalization of transducers on alumina substrate and without substrate. From these first achievements, we have submitted the means and characterization tools needed to evaluate the different steps of the technological process set up with a focus on the quality of the PZT material and its piezoelectric properties. It is first about morphological (SEM images, profilometer) and structural (XRD, EDX) studies, and then about the measurement of piezoelectric and dielectric values (piezometer, spectral and impedance analyses). In the third chapter we discussed the sensor, with the production of prototypes based on screen-printed transducers developed in Chapter 2. The sensors were tested and calibrated with solutions of ethanol and toluene. For this, the screen-printed sensors were tested in experimental benches to validate the measurement technique of the acoustic waves time of flight. In view of the miniaturization and the integration of the system, we have set an electronic control board with a dedicated module. Finally in order to improve the measurements, we have shown that we could consider crossing/correlating several parameters. Thus, we have developed a screen-printed sensor for the measurement of the electrical conductivity in aquatic environment. From the first experimental results we validated the principle of the method. In the fourth and final chapter of this manuscript, we presented the first studies and achievements on the LTCC technology. By repeating the process parameters used during deposition on alumina substrate, we realized and characterized transducers placed on on a LTCC ceramic sheet. The first morphological and piezoelectric characterizations are encouraging, and the first acoustic tests have shown that the generations of acoustic waves, and a use for the production of sensors of pollutants were possible with this technology. Finally we have been able to achieve a first 3D structure incorporating an analysis cavity. Here again, results are very encouraging, although "adjustments" are needed to improve the technology. Also this 3D realization opens up many opportunities for the team to develop new sensors
4
Zhu, Lingyu. „Color Contrast for Type on Screen“. University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1378108888.
Der volle Inhalt der Quelle
5
Weisenmiller, Eric Michael. „A Study of the Readability of On-Screen Type“. Diss., Virginia Tech, 1999. http://hdl.handle.net/10919/29400.
Der volle Inhalt der QuelleAnnotation:
This study examined the readability of fonts. More specifically, it investigated how four different fonts effected both reading rate and reading comprehension. The typefaces Georgia, Verdana, (which, according to their designers, optimize onscreen readability) Times, and Arial (both designed for digital output to hard copy) were displayed as treatments both on a computer screen and on paper. The purpose of the study was to determine whether sans serif and serif typefaces optimized for on-screen viewing significantly improve reading rate and reading comprehension. Comparisons were made among the typefaces using a categorical independent variable postmeasure-only research design to determine the level of dependent variables (rate, comprehension). The group means of each of twelve treatment groups (N=264) were analyzed using analyses of variance to determine if either of the variables (presentation mode or font) had a statistically significant effect upon reading rate and/or reading comprehension of a sample taken from a population of subjects attending a midwestern state university. No significant difference was found among reading speed or reading comprehension scores of subjects tested who read text which was typeset in any of the four typefaces. However, significant difference was found between the presentation modes used in the experiment.
Since it was found that 8-bit on-screen text was not significanly more readable than 600dpi text on paper, and 1-bit onscreen text was found to be significantly less readable than onscreen text and 600dpi text on paper, this research concludes that for purposes of ease of readability, onscreen text is better suited to be rendered as 8-bit onscreen text than 1-bit on-screen text. Also, the findings indicate that 8-bit on-screen text was not found to be significantly less readable than 600dpi text on paper. Also, due to the various typefaces currently being used in digital typography and the differing presentation media, further exploration of the readability of on-screen text should examine more fonts and screen display variables.Ph. D.
6
Edwards, Matthew Bruce ARC Centre of Excellence in Advanced Silicon Photovoltaics & Photonics Faculty of Engineering UNSW. „Screen and stencil print technologies for industrial N-type silicon solar cells“. Publisher:University of New South Wales. ARC Centre of Excellence in Advanced Silicon Photovoltaics & Photonics, 2008. http://handle.unsw.edu.au/1959.4/41372.
Der volle Inhalt der QuelleAnnotation:
To ensure that photovoltaics contributes significantly to future world energy production, the cost per watt of producing solar cells needs to be drastically reduced. The use of n-type silicon wafers in conjunction with industrial print technology has the potential to lower the cost per watt of solar cells. The use of n-type silicon is expected to allow the use of cheaper Cz substrates, without a corresponding loss in device efficiency. Printed metallisation is well utilised by the PV industry due to its low cost, yet there are few examples of its application to n-type solar cells. This thesis explores the use of n-type Cz silicon with printed metallisation and diffusion from printed sources in creating industrially applicable solar cell structures. The thesis begins with an overview of existing n-type solar cell structures, previous printed thick film metallisation research and previous research into printed dopant sources. A study of printed thick-film metallisation for n-type solar cells is then presented, which details the fabrication of boron doped p-type emitters followed by a survey of thick film Ag, Al, and Ag/Al inks for making contact to a p-emitter layer. Drawbacks of the various inks include high contact resistance, low metal conductivity or both. A cofire regime for front and rear contacts is established and an optimal emitter selected. A study of printed dopant pastes is presented, with an objective to achieve selective, heavily doped regions under metal contacts without significantly compromising minority carrier lifetime in solar cells. It is found that heavily doped regions are achievable with both boron and phosphorus, but that only phosphorus paste was capable of post-processing lifetime compatible with good efficiencies. The effect of belt furnace processing on n-type silicon wafers is explored, with large losses in implied voltage observed due to contamination of Si wafers from transition metals present in the belt furnace. Due to exposure to chromium in the belt furnace, no significant advantage in using n-type wafers instead of p-type is observed during the belt furnace processing step. Finally, working solar cells with efficiencies up to 16.1% are fabricated utilising knowledge acquired in the earlier chapters. The solar cells are characterised using several new photoluminescence techniques, including photoluminescence with current extraction to measure the quality of metal contacts. The work in this thesis indicates that n-type printed silicon solar cell technology shows potential for good performance at low cost.
7
Mahmoud, Sedky Mohamed Moustafa. „Evaluation of conducting screens as flux barriers in three types of electromagnetic devices“. Thesis, Heriot-Watt University, 2004. http://hdl.handle.net/10399/323.
Der volle Inhalt der Quelle
8
Giedraitis, Vilmantas. „Candidate gene analyses and genome-wide screens in multiple sclerosis /“. Stockholm, 2002. http://diss.kib.ki.se/2002/91-7349-408-9/.
Der volle Inhalt der Quelle
9
Chatterjee, Sudesna. „Outcomes and phenotype of subjects with screen-detected diabetes and new emerging therapies for type 1 and type 2 diabetes mellitus“. Thesis, University of Leicester, 2007. http://hdl.handle.net/2381/4735.
Der volle Inhalt der QuelleAnnotation:
Principal aims were to investigate long-term outcomes from T2DM and IGT screening, examine morphological and biochemical phenotypes of screened subjects, comparing White Europeans (WE) with South Asians (SA), and emerging therapies including basal insulin analogues in T!DM and meglitinides in T2DM and their place in management. Following adjustment for age, sex and ethnicity, no significant difference in mortality microvascular or macrovascular outcomes were detected between known and screened T2DM after ten years. Findings were limited by few events and relatively short follow-up. These data may be useful in power calculations for longer randomised controlled trials. Body fat is higher in SA than WE for given BMI and increases with worsening glucose tolerance. Bioelectrical impedance analysis and skinfold thickness are less sensitive and specific with increasing body fat regardless of ethnicity and gender. Ethnicity and BMI, but not age, predicts total and abdominal fat using DEXA scanning. After adjustment for age, BMI, WHR, gender, smoking and drug history, no differences between SA and WE for adiponectin and resistin were detected. Leptin is predicted by age, gender and smoking in WE but only gender in SA. BMI predicts hsCRP in both groups while age and smoking predicts TNFalpha in SA. Longitudinal cohort studies are needed to determine impact of interventions on risk markers in different ethnic groups. Insulin glargine results in a small but significant glycaemic improvement without significantly increased hypoglycaemia, weight gain or reduced patient satisfaction when used in a basal bolus regimen with aspart compared with NPH insulin in T1DM. In a six month randomised study, four different dual oral combinations including nateglinide, pioglitazone, metformin and gliclazide, in early T2DM result in significant glycaemic improvement without increasing hypoglycaemia or patient dissatisfaction with no significant differences between groups. Longer RCT are required to determine duration of glycaemic improvement with each combination.
10
Dann, Fiona. „Type 2 diabetes and depression : an exploration into the most effective depression screen to be used in a type 2 diabetes population /“. [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18463.pdf.
Der volle Inhalt der Quelle
11
Hosp, Fabian. „A quantitative interaction screen for neurodegenerative disease proteins“. Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2013. http://dx.doi.org/10.18452/16669.
Der volle Inhalt der QuelleAnnotation:
Der erste Teil dieser Arbeit beschreibt die Durchführung eines quantitativen Ansatzes zur Detektion von Protein-Protein-Interaktionen (PPI) mit einem Schwerpunkt für Proteine, die in vier häufigen neurodegenerativen Krankheiten eine Rolle spielen: die Alzheimer-, Parkinson- und Huntington-Krankheit, sowie die spinozerebelläre Ataxie Typ 1 (SCA1). Die Interaktionsstudie kombiniert die stabile Isotopen-Markierung von Aminosäuren in der Zellkultur mit der Affinitätsaufreinigung von Proteinen und hochauflösender Massenspektrometrie. Dieser Ansatz zielt darauf ab, systematisch die Interaktionspartner von gesunden und krankheitsassoziierten Proteinvarianten zu identifizieren und zu quantifizieren. Darüber hinaus wurde das quantitative Interaktionsverfahren genutzt, um zu prüfen ob PPI durch krankheitsassoziierte Mutationen beeinträchtigt werden. Neben der Validierung möglicher Nebeneffekte, sowie dem Vergleich mit Informationen über PPI aus der Literatur, wurde ein Teil der identifizierten Interaktoren durch zusätzliche Koimmunopräzipitations-Experimente in zwei verschiedenen Zelllinien bestätigt. Mit Hilfe von Drosophila SCA1-Krankheitsmodellen und in Kombination mit RNAi-basierter Stummschaltung identifizierter Interaktoren wurde festgestellt, dass ein großer Teil der Kandidaten Neurodegeneration in vivo beeinflusst. Zusätzlich wurden die Alzheimer-spezifischen PPI-Daten auf genomweite Assoziationsstudien übertragen. Bemerkenswerterweise waren Polymorphismen in einzelnen Nukleotiden in den Genen zugehöriger Interaktoren wahrscheinlicher mit solchen Genen assoziiert, die eine Prädisposition für die Alzheimer-Krankheit haben, als mit zufällig ausgewählten Genen. Schlussendlich konnten Folgeexperimente für zwei ausgewählte Interaktionspartner den Nachweis für eine bislang unbekannte Rolle der N-Glykosylierung und einen neuen Zusammenhang zwischen dem RNA-bindenden Protein LRPPRC und mitochondrialer Dysfunktion in der Alzheimer-Krankheit vorlegen.The first part of the present thesis describes the establishment of a quantitative protein-protein interaction (PPI) screen with a focus on proteins involved in four common neurodegenerative diseases (NDDs): Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD) and spinocerebellar ataxia type 1 (SCA1). The interaction screen combines stable-isotope labeling by amino acids in cell culture (SILAC) with protein affinity purification and high-resolution mass spectrometry. This approach aims to systematically identify and quantify interaction partners of normal and known disease-associated variants of proteins involved in NDDs. Moreover, the quantitative interaction screen was employed to study how PPIs are affected by disease-associated mutations. Along with validation of possible off-target effects and comparison of the data with literature-reported PPIs, a subset of identified interactors was validated by additional co-immunoprecipitation experiments in two different cell lines. Utilizing Drosophila models for SCA1 in combination with RNAi-mediated silencing of identified interactors, a large fraction of candidates was observed to also affect neurodegeneration in vivo. In addition, AD-specific PPI data was mapped to patient cohort data obtained from genome-wide associations studies. Notably, single-nucleotide polymorphisms in the genes of interactors of the disease-associated protein variants were more likely associated with susceptibility to AD than randomly selected genes. Finally, functional follow-ups for two selected interaction partners provided evidence for a yet unreported role of N-linked glycosylation in AD, and a novel link to mitochondrial dysfunction in AD by means of the RNA-binding protein LRPPRC.
12
Bock, Robert [Verfasser]. „Screen-printed aluminium-doped p+ emitters for the application to n-type silicon solar cells / Robert Bock“. Hannover : Technische Informationsbibliothek und Universitätsbibliothek Hannover (TIB), 2011. http://d-nb.info/1017379106/34.
Der volle Inhalt der Quelle
13
Kurum, Mustafa Onur. „An Experimental Study On The Performance Of Box Type Floating Breakwaters With Screens“. Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/2/12609633/index.pdf.
Der volle Inhalt der QuelleAnnotation:
In the present thesis the performance of box type floating breakwaters (FBs) with
screens under regular waves is examined experimentally in a wave flume. The experiments
were conducted in the Coastal and Harbor Engineering Laboratory wave
flume, Civil Engineering Department, Middle East Technical University, Ankara. The
influence of incident wave characteristics and certain geometric characteristics, such
as the width and draft of the structure, on its effciency is examined. Three different
widths of the structure in combination with three different screen (draft) height, a total
of nine different cases, of FBs are examined. Results related to transmission and
reflection of the incident regular waves on the structure are presented. According to
the results, for all structures drafts and structure widths, as h/L increase (wave period
and wave height decreases) Kt values decrease. Also, Kt values obtained for chain
moored floating breakwaters are larger than the Kt values of fixed cases consistently.
14
Ramachandran, Sulabha. „Equivalence of Paper and Touch Screen Versions of the EQ-5D Visual Analog Scale (EQ-VAS)“. Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1381%5F1%5Fm.pdf&type=application/pdf.
Der volle Inhalt der Quelle
15
Raciti, Daniela. „A large-scale gene discovery screen identifies over hundred solute carrier (SLC) genes with organ specific expression patterns in the Xenopus embryo /“. Zürich : ETH, 2007. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17204.
Der volle Inhalt der Quelle
16
Chen, J. A. „Cyclin Dx, a novel cell-type specific cyclin identified from an enhanced functional screen, regulates the differentiation of motor neurons in Xenopus“. Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.597520.
Der volle Inhalt der QuelleAnnotation:
The formation of mesoderm is an important development process of vertebrate embryos, which can be broken down into several steps; mesoderm induction, patterning, morphogenesis and differentiation. Although mesoderm formation in Xenopus has been intensively studied, much remains to be learned about the molecular events responsible for each of these steps. Furthermore, the interplay between mesoderm induction, patterning and morphogenesis remains obscure. Here, I describe an enhanced functional screen in Xenopus designed for large-scale identification of genes controlling mesoderm formation. In order to improve the efficiency of the screen, I used a Xenopus tropicalis unique set of cDNAs, highly enriched in full-length clones. The screening strategy incorporates two mesodermal markers, bra and myf5, to assay for cell fate specification and patterning, respectively. In addition I looked for phenotypes that would suggest effects in morphogenesis, such as gastrulation defects and shortened anterior/posterior axis. To maximise the output of this screen, several other non-mesodermal phenotypes were recorded as well. Out of 1728 full-length clones I isolated 82 for their ability to alter the phenotype of tadpoles and/or the expression of bra and myf5. Many of the clones gave rise to replace the lost islet1+ expressing cells. Thus, I conclude that the major function of cyclin Dx is to maintain motor neuron progenitors and provides a temporal cue for cell cycle exit of pMNs in the developing Xenopus neural tube. These results provide the first evidence that a cell-type specific cyclin can control the timing of cell cycle exit to create diversity of differentiating motor neurons and could contribute to our understanding of how the cell cycle control can contribute to neuronal diversity in the neural tube.
17
Feng, Gang [Verfasser]. „Biomechanical comparison of anterior screw fixation techniques for type II odontoid fractures : One- versus two-screw fixation / Gang Feng“. Lübeck : Zentrale Hochschulbibliothek Lübeck, 2011. http://d-nb.info/1017565600/34.
Der volle Inhalt der Quelle
18
Jeter, Lauren M. „CONSUMER PURCHASE DECISIONS REGARDING SCREW CAP WINES“. DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/886.
Der volle Inhalt der QuelleAnnotation:
Screw cap wine closures provide many benefits in maintenance of wine quality over time, however acceptance of their use by purchasers has varied. This work first investigates how factors like age, gender, income and education affect the decision to purchase screw cap wines and to what extent these factors impact consumer decisions to bring screw cap wine to various social settings. The results of a questionnaire pooling attitudes and behaviors of wine purchasers (n=319) indicate that factors such as age, wine knowledge, income and gender influence a consumer’s decision to purchase screw cap wine. Education and income positively impact the acceptance of screw cap wines and the likelihood of purchasing them. Age has a negative effect on acceptance of screw cap wines in social situations. Gender was found to not be significant in regards to likelihood of screw cap wine purchase generally, however men tended to view screw cap wines as more acceptable in more social situations than women.
19
Fan, Yannan. „Tissue-specific gain of wild-type RTK levels combined with screen strategies identify new mechanisms of cell vulnerability in developmental and tumorigenic programs“. Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4071.
Der volle Inhalt der QuelleAnnotation:
Pour étudier la capacité cellulaire à s’adapter aux changements de signalisation dépendante des RTKs, nous utilisons un modèle de souris où l’expression du RTK Met sauvage peut être accrue dans un tissu spécifique. La plupart des tissus se protègent contre cette expression anormale des RTK. Mais certains types cellulaires sont sensibles aux altérations des RTKs, c’est le cas du mésenchyme du membre pendant l’embryogenèse. En effet, l’expression de certains gènes du mésenchyme est modifiée et celui-ci n’est plus accessible aux myoblastes qui le colonisent, conduisant à des déficits des muscles du membre. Chez l’adulte une augmentation de l’expression de Met dans le foie (Alb-R26Met) perturbe l’homéostasie tissulaire, conduisant à la tumorigenèse. Pour identifier des gènes qui coopèrent avec les RTKs pendant l’initiation de la tumorigenèse, nous avons combiné les souris Alb-R26Met avec le système de mutagenèse Sleeping Beauty (SB) transposon. 285 gènes putatifs liés au cancer ont été identifiés. Certains sont des proto-oncogènes ou suppresseurs de tumeurs déjà connus, validant le système. D’autres gènes n’avaient, jusqu’à présent, jamais été associés à ce processus. 9 candidats ont été fonctionnellement validés. Pour identifier des signaux assurant le maintien de la tumeur, nous avons analysé le phosphokinome, testé l’efficacité de composés et identifié de nouvelles combinaisons de drogues qui agissent en synergie pour tuer les cellules cancéreuses dérivées de Alb-R26Met. En conclusion, ces travaux montrent qu’une approche génétique non-biaisée combinée à une approche génomique permet d’identifier de nouveaux mécanismes pertinents pour la biologie du cancerWe explore the cell competence to deal with slight changes in RTK inputs during embryogenesis and tissue homeostasis using a mouse model in which wild-type RTK Met levels can be moderately enhanced in a tissue specific manner. Most tissues buffer enhanced RTK levels thus avoiding perturbation of developmental programs and tissue homeostasis. Nevertheless, certain cell types are vulnerable to RTK levels. During embryogenesis, the limb mesenchyme is sensitive to alterations of the spatial distribution of RTKs, as illustrated by gene expression changes and by loss of accessibility to incoming myoblasts, which lead to limb muscle defects. At adulthood, liver enhanced Met levels (Alb-R26Met) perturbs tissue homeostasis, leading to tumorigenesis. To uncover new genes that cooperate with RTKs during tumour initiation, we combined Alb-R26Met mice with the Sleeping Beauty (SB) transposon mutagenesis system. 285 putative cancer-related genes have been identified. Some correspond to known proto-oncogenes or tumour suppressors, thus validating the overall strategy we employed for cancer gene discovery. Others have not been previously linked to cancer. 9 new tumour suppressors have been functionally validated, demonstrating the validity of our screen strategy. To identify signals involved in tumour maintenance, we employed a phosphokinome-guided drug screen and identified new synergistic drugs deleterious for cancer cells modelled by the Alb-R26Met genetic setting. The overall strategy and outcomes strengthen the value of combining unbiased genetic and genomic approaches to identify new mechanisms relevant for cancer biology and new therapeutic interventions
20
Szathmary, Reka. „Identification of novel mechanisms in ERAD : Genetic and biochemical characterization of the YOS9 protein and Genetic screens to identify novel genes in ERAD /“. Zürich : ETH, 2005. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=16155.
Der volle Inhalt der Quelle
21
林肖明 und Chiu-ming Lam. „Visualization studies on the dynamic processing characteristics of conventional full-flighted and barrier type single-screws“. Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31222845.
Der volle Inhalt der Quelle
22
Lam, Chiu-ming. „Visualization studies on the dynamic processing characteristics of conventional full-flighted and barrier type single-screws /“. Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B21904182.
Der volle Inhalt der Quelle
23
Reynolds, Thomas Peter Shillito. „Dynamic behaviour of dowel-type connections under in-service vibration“. Thesis, University of Bath, 2013. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.608327.
Der volle Inhalt der QuelleAnnotation:
This study investigated the vibration serviceability of timber structures with dowel-type connections. It addressed the use of such connections in cutting-edge timber structures such as multi-storey buildings and long-span bridges, in which the light weight and flexibility of the structure make it possible that vibration induced by dynamic forces such as wind or footfall may cause discomfort to occupants or users of the structure, or otherwise impair its intended use. The nature of the oscillating force imposed on connections by this form of vibration was defined based on literature review and the use of established mathematical models. This allowed the appropriate cyclic load to be applied in experimental work on the most basic component of a dowel-type connection: a steel dowel embedding into a block of timber. A model for the stiffness of the timber in embedment under this cyclic load was developed based on an elastic stress function, which could then be used as the basis of a model for a complete connector. Nonlinear and time-dependent behaviour was also observed in embedment, and a simple rheological model incorporating elastic, viscoelastic and plastic elements was fitted to the measured response to cyclic load. Observations of the embedment response of the timber were then used to explain features of the behaviour of complete single- and multiple-dowel connections under cyclic load representative of in-service vibration. Complete portal frames and cantilever beams were tested under cyclic load, and a design method was derived for predicting the stiffness of such structures, using analytical equations based on the model for embedment behaviour. In each cyclic load test the energy dissipation in the specimen, which contributes to the damping in a complete structure, was measured. The analytical model was used to predict frictional energy dissipation in embedment, which was shown to make a significant contribution to damping in single-dowel connections. Based on the experimental results and analysis, several defining aspects of the dynamic response of the complete structures, such as a reduction of natural frequency with increased amplitude of applied load, were related to the observed and modelled embedment behaviour of the connections.
24
Kortekangas, T. (Tero). „The non-operative treatment of Weber B -type ankle fractures and the clinical relevance and treatment of syndesmosis injury“. Doctoral thesis, Oulun yliopisto, 2017. http://urn.fi/urn:isbn:9789526216607.
Der volle Inhalt der QuelleAnnotation:
Abstract Despite numerous biomechanical and clinical studies on ankle fractures, the optimal treatment method for a stable fibula fracture is poorly known. Additionally, the clinical relevance and optimal fixation method of syndesmosis injury for different ankle fracture types is unclear. This thesis aimed: (I) to compare six weeks of cast immobilization with three weeks of immobilization (cast or orthosis) in a randomized controlled trial (RCT) of 247 patients with stable Weber B-type fibular fracture; (II) to compare mid-term outcome of syndesmosis transfixation with no fixation in an RCT of 24 patients with supination external rotation (SER) ankle fractures and syndesmosis injury; (III) to evaluate the significance of the syndesmosis injury on clinical outcome in a case-control study of 48 patients with SER ankle fractures; and (IV) to compare the syndesmosis fixation with a screw versus a suture-button device in terms of the accuracy and the maintenance of syndesmosis reduction in an RCT of 43 patients with pronation external rotation (PER) ankle fractures. Three weeks of immobilization in either a cast or an orthosis resulted in non-inferior outcomes compared to traditional six weeks’ immobilization in patients with stable Weber B-type fibula fracture. In patients with SER ankle fracture and unstable syndesmosis after fixation of bone fractures, leaving unstable syndesmosis unfixed resulted in similar outcomes compared to syndesmosis transfixation at mid-term follow-up. Patients with SER ankle fractures with or without an associated syndesmosis injury had similar clinical outcomes after a minimum of four years of follow-up. The syndesmotic screw and the suture-button fixation in patients with PER ankle fracture and unstable syndesmosis resulted in a low malreduction rate and both methods maintained reduction well. In conclusion, stable Weber B-type fibula fractures can safely be treated with only three weeks of cast immobilization or even with a simple orthosis. A syndesmosis injury in SER ankle fractures seems to be of minor therapeutic or prognostic importance and syndesmosis screw fixation has no effect on patient’s recovery compared to no syndesmosis fixation. An associated syndesmosis injury in PER ankle fractures can be fixed with a syndesmotic screw or a suture-button device with comparable outcomesTiivistelmä Stabiilin nilkkamurtuman konservatiivisen hoidon toteutuksesta on hyvälaatuista tutkimustietoa tarjolla niukasti. Syndesmoosivamman kliininen merkitys ja sen hoitomenetelmät eri nilkkamurtumatyypeissä ovat kirjallisuuden perusteella vielä osittain epäselvät. Ensimmäisessä osatyössä vertailtiin kolmen viikon immobilisaatiota (kipsi tai ortoosi) perinteiseen kuuden viikon kipsihoitoon satunnaistetussa ja kontrolloidussa tutkimuksessa, joka käsitti 247 stabiilin Weber B-tyypin pohjeluun murtuman saanutta potilasta. Toisessa osatyössä vertailtiin syndesmoosin ruuvikiinnitystä kiinnittämättä jättämiseen satunnaistetussa ja kontrolloidussa tutkimuksessa, johon osallistui 24 SER (supinaatio-ulkorotaatio) -tyypin nilkkamurtumapotilasta, joilla todettiin syndesmoosin epävakaus leikkauksen aikaisessa rasituskokeessa. Kolmannessa osatyössä selvitettiin syndesmoosivamman kliinistä merkitystä SER-tyypin nilkkamurtumapotilailla tapaus-verrokki-asetelmassa. Neljännessä osatyössä vertailtiin syndesmoosin ruuvi- ja jännitelankakiinnitystä syndesmoosin kiinnitystarkkuuden ja kiinnityksen pysyvyyden suhteen satunnaistetussa ja kontrolloidussa tutkimuksessa, joka käsitti 43 PER (pronaatio-ulkorotaatio) -tyypin nilkkamurtuman saanutta potilasta. Stabiilin Weber B-tyypin pohjeluun murtuman hoidossa kolmen viikon immobilisaatio joko kipsillä tai ortoosilla oli yhtä hyvä ja turvallinen kuin perinteinen kuuden viikon kipsihoito. Syndesmoosin ruuvikiinnitettyjen ja kiinnittämättä jätettyjen SER-tyypin nilkkamurtumapotilaiden hoitotuloksissa ei todettu merkittäviä eroja keskipitkän aikavälin seurannassa. Syndesmoosivammalla ei todettu merkitystä SER-tyypin nilkkamurtuma-potilaiden hoitotulokseen tai ennusteeseen vähintään neljän vuoden seurannan jälkeen. Syndesmoosin reduktion suhteen ruuvi- ja jännitelankakiinnityksellä saadaan yhtä hyvät varhaisvaiheen tulokset PER-tyypin nilkkamurtumapotilailla ja molemmat kiinnitysmenetelmät säilyttävät syndesmoosin reduktion hyvin. Stabiilin Weber B -tyypin pohjeluun murtuman hoito voidaan toteuttaa turvallisesti ja tehokkaasti kolmen viikon immobilisaatiolla joko nilkkaortoosilla tai saapaskipsillä. Syndesmoosivammalla ei vaikuta olevan kliinistä merkitystä SER-tyypin nilkkamurtumapotilaan ennusteeseen, eikä vamman hoitaminen ruuvikiinnityksellä paranna potilaan hoitotulosta kiinnittämättä jättämiseen verrattuna. PER-tyypin nilkkamurtumiin liittyvän syndesmoosivamman korjauksessa voidaan käyttää joko ruuvikiinnitystä tai jännitelankasidosta yhtä hyvin hoitotuloksin
25
Salhi, Lakhdar. „Contribution à l’étude des comportements mécaniques et à la corrosion d’un système de fondation de type pieu vissé dans un sol mou en environnement tropical humide“. Thesis, Antilles-Guyane, 2014. http://www.theses.fr/2014AGUY0790/document.
Der volle Inhalt der QuelleAnnotation:
L’objet de cette thèse est l’étude des comportements mécanique et à la corrosion d’un nouveau système de fondation, dit pieux SPIRMEC, adapté aux structures légères. Le travail s’est focalisé sur deux grands aspects. Le premier aspect concerne l’analyse du comportement sous chargement axiale des pieux SPIRMEC sur la base de l’expérimentation et de la modélisation numérique dans un sol mou non cohésif. Quant au deuxième aspect, il traite du problème de la corrosion de l’acier constituant le pieu dans un environnement tropical humide. Le comportement des pieux SPIRMEC sous une charge axiale de traction, dans un sol fin non cohésif, a montré le développement d’une surface cylindrique de rupture. Celle-ci ne dépend pas de la configuration géométrique des pieux tel que : l’espacement S, le diamètre d’hélice Dh et le diamètre du tube d. En adoptant ce critère de rupture et à l’aide d’une analyse statistique des données, nous avons proposé quatre méthodes analytiques de prédiction de la capacité portante des pieux SPIRMEC à partir des essais in-situ et au laboratoire qui sont: • Méthode CPT basée sur la résistance de pointe pénétromètrique (essai CPT), • Méthode MPT basée sur la pression limite pressiomètrique (essai MPT), • Méthode du couple d’installation, • Méthode analytique basée sur les paramètres de cisaillement de sol notamment l’angle de frottement interne (essais triaxial et boîte de cisaillement). Ces méthodes tiennent compte de la géométrie du pieu, du procédé de mise en oeuvre et de la compacité du sol. L’analyse de performance des méthodes proposées a montré que les méthodes analytique et CPT représentent mieux le comportement des pieux testés. La modélisation numérique du comportement des pieux SPIRMEC sous charge axiale de traction a été également étudiée à l’aide du code de calcul Plaxis 2D. Un modèle axisymétrique a été adopté pour modéliser la géométrie de la structure. Le modèle de comportement hardening soil a été retenu pour modéliser le comportement élastoplastiq des couches de sol. Un modèle élastique linéaire a été retenu pour le pieu. Quant au comportement de l’interface sol-structure, il a été pris en compte par un modèle élastoplastique basé sur les critères de Mohr-Coulomb. L’expansion du sol résultant de l’installation des pieux a été approchée par une cavité cylindrique. Cette dernière a été modélisée par des déformations volumiques anisotropes. Nous avons constaté, qu’appliquer une déformation volumique de l’ordre de 40% permet une bonne concordance entre les résultats numériques et expérimentaux. L’étude paramétrique nous a également permis de constater l’existence d’une variation linéaire entre la capacité portante et l’espacement S. Le comportement de l’acier galvanisé dans le sol a été également étudié au moyen de trois approches: électrochimique, visuelles grâce au microscope électronique et gravimétrique. Les tests électrochimiques de corrosion du zinc ont été réalisés dans la solution de sol artificielle pour deux périodes bien distinctes : saison des pluies et après 8 mois de contact sol-pieu. Une forte dépendance est constatée de la vitesse de corrosion de zinc au pH et à la conductivité de la solution. La vitesse de corrosion est plus importante en saison des pluies qu’après 8 mois de contact de pieu avec le sol. Les fortes concentrations en sulfates semblent augmenter la vitesse de corrosion. Les analyses menées au MEB montrent que la zone de fluctuation de nappe et en surface externe (sol/air) sont les zones les plus corrodées. La comparaison entre les différentes techniques d’évaluation de la vitesse de corrosion a montré que l’eau de nappe peut être utilisée comme un milieu représentatif du profil chimique d’un sol non cohésif et légèrement granulaireThe purpose of this thesis is to study the both behaviors mechanical and of the corrosion of a new foundation system, called spirec piles, for lightweight structures. The work was based on two main aspects. The first aspect concerns the analysis of behavior of the spirmec piles under axial loading on the basis of experimental and numerical modeling in a non-cohesive soft soil. On the second aspect, it addresses the problem of corrosion of steel forming the pile in a humid tropical environment. The behavior of the tested piles under axial traction load, in a non-cohesive soil, showed the development of a cylindrical surface of failure. This does not depend on the geometrical configuration of the tested piles such that: the spacing s, the helix diameter dh and the diameter of the shaft. By adopting this failure criterion and using statistical data analysis, we proposed four analytical methods for predicting the bearing capacity of the piles from in-situ and laboratory tests, which are: cpt method based on tip resistance penetrometer (cpt test), mpt method based on pressuremeter limit pressure (test mpt), method of installation torque and analytical method based on the shear parameters of soil (triaxial tests and shear box). These methods take into account the geometry of the pile, the method and implementation of soil compaction. Performance analysis of the proposed methods showed that the analytical methods and cpt represent better the behavior of piles tested. An axisymmetric condition was assumed to model this geometry in two-dimensional space. In this study, we proposed to model the pipe screw pile with plates elements available in plaxis 2d. The helixes were modeled as circular disks. Interface elements were incorporated along the pile to simulate the soil-pile interaction. Hardening soil model was chosen to describe the soil with drained behavior was assigned for all layers. Linear elastic for pile and elastic plastic model based on the mohr-coulomb criterion was used to describe the interface behavior. The lateral expansion generated by the pile shaft was modeled by anisotropic volumetric strains (ɛxx=ɛzz, ɛyy=0). The pile behavior under tensile loading at different volumetric strains, it is clear that the best fit was obtained at volumetric strain of 40%. The parametric study also allowed us to establish the existence of a linear variation between the bearing capacity and spacings. The behavior of the galvanized steel in the ground has also been studied using three approaches such as: electrochemical, microscopic imaging and gravimetrically. Electrochemical tests of the corrosion of the zinc have been made in artificial soil solution into two periods, the rainy season and after eight months of contact soil-pile. Is a strong dependence of the observed corrosion rate of the zinc at the ph and conductivity of the solution. The corrosion rate is higher in the rainy season compared to eight months of contact of the pile with soil. High sulfate concentrations increase the rate of corrosion. The meb analysis shows that the fluctuation zone of the water table is the most corroded area. Comparison between the different methods of evaluating the corrosion rate showed that the ground water may be used as a representative profile of the chemical environment of a non-cohesive soil and slightly granular
26
Eckardt, Ronny. „Untersuchungen an Verbindungselementen für Holzkonstruktionen im Maschinen- und Anlagenbau“. Doctoral thesis, Universitätsbibliothek Chemnitz, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-106287.
Der volle Inhalt der QuelleAnnotation:
In dieser Arbeit werden Berechnungsvorschriften für Insertverbindungen in Holzfurnierlagenverbundwerkstoffen (WVC) mit dem Ziel erstellt, diese zur Auslegung und Nachweisführung in Anwendungen des Maschinenbaus zu verwenden. Nach Definition eines entsprechenden Anforderungsprofils erfolgt eine umfangreiche Darstellung des Standes der Technik. Dabei wird speziell auf die rechnerische Nachweisführung von Verbindungen im Bauwesen eingegangen, schwerpunktmäßig durch die im Eurocode 5 (DIN EN 1995) definierten Modelle für stiftförmige Verbindungsmittel. Im zweiten, praktischen Teil der Arbeit erfolgt die Durchführung und Auswertung umfangreicher Versuche. Dabei werden in einem ersten Schritt wesentliche Materialkennwerte der verwendeten Holzwerkstoffe bestimmt. Die zweite Gruppe der experimentellen Untersuchungen hat das Trag- und Verformungsverhalten vollständiger Insertverbindungen zum Inhalt. Dabei werden die unter statischen Aspekten wichtigen Einflussparameter auf die Tragfähigkeit bei Belastungen in Richtung sowie quer zur Stiftachse bestimmt und geometrische Vorzugsparameter ermittelt. Unter deren Zugrundelegung erfolgt eine Ausweitung der experimentellen Untersuchungen auf dynamische Lastfälle durch eine Ableitung von Wöhlerlinien bei Zugschwellbelastung. Auf Grundlage der durchgeführten Versuche werden Modelle zur Berechnung von Insertverbindungen nach den Methoden des Ingenieurholzbaus abgeleitet. Deren Anwendbarkeit wird an einem konkreten Beispiel in Form einer Transportrollenbahn für die Verwendung in der technischen Intralogistik demonstriertIn this work, calculation fundamentals for insert fastenings in wood veneer composites (WVC) are developed with the aim to use them for the dimensioning and verification in mechanical engineering applications. After defining the functional requirements there is a comprehensive description of the best demonstrated available technology. The arithmetical verifications of connections used in civil engineering are thereby specifically addressed with the main focus on defined models for dowel type fasteners within Eurocode 5 (EN 1995). In the second part of the work comprehensive technical tests are implemented and evaluated. At first essential material properties of the used wood materials are determined. The following experiments contain the load bearing and deformation behavior of complete insert connections. The determination of important influencing parameters of the statical strength under axial and traverse loads is thereby involved, followed by an extension on dynamic load cases by a derivative of Woehler curves (stress - cycle diagram). Based on these experiments are models derived to provide calculation fundamentals to dimension insert connections. The practical applicability of the developed specifications is shown by dimensioning the connections of a roller conveyor made of WVC (technical logistics)
27
Yang, Tzong-Ke, und 楊宗珂. „The Effects of Homepage Screen Density and Personality Types on Users' Attitudes and Intentions toward the Web Sites“. Thesis, 2010. http://ndltd.ncl.edu.tw/handle/07723692657941544838.
Der volle Inhalt der QuelleAnnotation:
博士國立交通大學
管理科學系所
98
Many homepages are crowded with a huge amount of information and ads. However, little evidence has examined how people evaluated a Web site with such a high-density homepage. Therefore, this study empirically investigates the effects of homepage screen density on users’ Web site evaluations in term of attitudes and behavioral intentions towards a Web site. In addition, this paper examines whether a user’s personality affects his or her Web site evaluation. Results of an experiment that manipulated the density of the homepage screen show that subjects prefer homepages with a moderate screen density; that homepage screen density significantly influences the Web site evaluations of Intuition and Feeling types, but not of Sensing and Thinking types; and that homepage screen density significantly influences the Web site evaluations of Intuitive-Feelers (NF), but not of Sensing- thinkers (ST). The practical implications of the findings are that although a moderate-density homepage design is a general condition for positive Web site evaluations, the influences of individual difference in personality types must also be considered.
28
Figley, Laura C. „Perceptual differences in the conversational performance of people with severe expressive aphasia using three types of visual screen displays on speech generating devices“. 2007. http://etd1.library.duq.edu/theses/available/etd-07272007-085658/.
Der volle Inhalt der Quelle
29
Seale, Jennifer M. „Quantitative differences in the conversational performance of people with severe expressive aphasia using three types of visual screen displays on speech generating devices“. 2007. http://etd1.library.duq.edu/theses/available/etd-07282007-121053/.
Der volle Inhalt der Quelle
30
Nguyen, Manh-Tan, und 阮錳新. „Effects of Screen-Printed Aluminum-Alloyed Front Emitter on Characteristics of Screen-Printed N-Type Mono-Crystalline Silicon Solar Cells“. Thesis, 2012. http://ndltd.ncl.edu.tw/handle/28z24k.
Der volle Inhalt der QuelleAnnotation:
碩士國立虎尾科技大學
光電與材料科技研究所
101
Effects of screen-printed aluminum-alloyed front emitter (AAFE) on characteristics of screen-printed N-type mono-crystalline silicon solar cells (SPNMSSC) were presented. The sheet resistance and the thickness of AAFE in SPNSSCs can be tuned by the firing temperature, the firing time, the waiting time, and the etching time of the KOH solution, respectively. The results show that the sheet resistance decreases from 250 to the 10 Ω/sq with increasing the firing time, respectively. On the other hand, the sheet resistance decreases with decreasing the waiting time. And with increasing etching time of the KOH solution, the sheet resistance of the Al-p+ was increased, and the thickness of the Al-p+ front surface field was decreased. Moreover, the larger thickness of the front surface field (FSF) can be achieved by increasing firing temperature and time. The optimum conversion efficiency can be obtained by suitably turned process parameters.
31
Ji, Guan-Yu, und 紀冠宇. „Improved Photovoltaic Characteristics of Screen-Printed N-type Monocrystalline Silicon Solar Cells by Screen-Printed Diffusion and Laser Texturization Techniques“. Thesis, 2013. http://ndltd.ncl.edu.tw/handle/dvr3bx.
Der volle Inhalt der QuelleAnnotation:
碩士國立虎尾科技大學
光電與材料科技研究所
101
In this study, the Nd : YAG laser with a wavelength of 1064 nm was used to form various texturing patterns. The laser parameters include the power, the spacing of the laser line, the pattern, the frequency, and the speed of the laser. After laser pattern, the potassium hydroxide (KOH) solution was used to demonstrate various micro-grooved pyramids. The low reflection of surface and the high path of optical can be enhanced by the micro-grooved pyramids. Then, the screen-printed diffusion technique (SPDT) was adopted for fabrication simply and at low-cost solar cell applications. The conditions of SPDT include the squeegee speed, the emulsion thickness, the snap-off setting, the diffusion time, the gas flow, and the diffusion barrier layer. The better photovoltaic characteristics of the screen-printed mono-crystalline silicon solar cells can be demonstrated for tuning parameter of SPDT. Compared with the KOH texturing surface, the reflection of the surface with combined the laser and the KOH solution texturization can be reduced around 5-10 % at the laser power of 10 %, the frequency of 30 KHz, the line spacing of 100 ?m, and the speed of 800 mm/min. The sheet resistance of the emitter (p+) was obtained around 40-60 ohm/square at the diffusion time of 40-100 min, and nitrogen (N2) flow of 80 sccm. Furthermore, the sheet resistance of the base (n+) can be obtained around 12-14 ohm/square at the diffusion time of 40 min, nitrogen (N2) flow of 50 sccm, and different diffusion barrier layers. Finally, the screen-printed n-type mono-crystalline silicon solar cells with a conversion efficiency of 12.20 %, a open circuit voltage (Voc) of 557 mV, a short-circuit current density (Jsc) of 40.11 mA/cm2, and a fill factor (FF) of 0.55 can be demonstrated at the co-firing temperature of 870 ℃ for 35sec.
32
Hsin, Pi-Yu, und 辛璧宇. „Screen-printed Interdigitated Back Contact Solar Cells on Cz P-type Wafer“. Thesis, 2018. http://ndltd.ncl.edu.tw/handle/s9tz8s.
Der volle Inhalt der Quelle
33
Cheng, Yuang-Cheng, und 鄭元政. „Development of semiconductor type CO sensor by using thick-film screen printing method“. Thesis, 2000. http://ndltd.ncl.edu.tw/handle/10907104725283242409.
Der volle Inhalt der QuelleAnnotation:
碩士中國文化大學
材料科學與製造研究所
88
ABSTRACT The purpose of this research is to develop a semiconductor type CO sensor by using thick-film screen printing method. To manufacture CO sensing layer by the powers of the ZnO and SnO2, then it is screen printing on the Al2O3 substrate of the sensing layer. To manufacture sensor electrode、 heater and sensing layer by using screen print mechanic, The objective is shrinking volume size of the sensor cell, economize the space size reducity the capital and simply the manufacture processes and mass production. By the screen coating method, we use solvent include Au、Pd catalyst coating on the sensing layer surface or use three-roller mechanic doping catalyst in the sensing layer, increase sensitivity and let working temperature down, and reducity response time and recovery time. From the research results we know that ZnO have high sensitivity to CO gas than SnO2, the sensitivity 5 at CO gas concentration 50 ppm. The temperature at 200℃need 0.5 watts can get higher sensitivity .Using the way of the surface coating we can get the best sensitivity when coating 5 layers catalyst, and response time is 8 seconds and recovery time is 66 seconds.
34
Ming-TingShih und 施明廷. „A Novel Dual Screen Projection System Using Balance-type Micromirror with Piezoelectric Actuator“. Thesis, 2011. http://ndltd.ncl.edu.tw/handle/11140651428457479787.
Der volle Inhalt der Quelle
35
Chang, Chin-Shun, und 張金順. „The Characteristics of The Bar-Screen Type Water Intake in Lao-Nong Weir“. Thesis, 2009. http://ndltd.ncl.edu.tw/handle/30990356462936880219.
Der volle Inhalt der QuelleAnnotation:
碩士國立中興大學
水土保持學系所
97
Usually applied in mountain streams, bar-screen water intakes are of small scale and allow for little water intake. However the largest of all bar-screen water intakes in Taiwan so far, the discharge capacity of the bar-screen water intake at Long-En Weir is only 6 cms. In fact, bar-screen water intakes of large discharge capacity are scarce even abroad. Hence, few data could be used as reference. Now under construction by the Water Resource Agency of the Ministry of Economics Affair, R.O.C., the Lao-Nong Weir contains two units of bar screens which of the same size will allow for a total discharge capacity of 50 cms after the construction and hence earn the reputation of the largest bar-screen water intake in Taiwan. This research paper is set to investigate the effectiveness of Lao-Nong Weir’s water intake in order to serve as reference for future practical operations and designs. To investigate the effectiveness and characteristics of Lao-Nong Weir’s water intake at different medium-low flow rates, the simulation model of Lao-Nong Weir was operated under the following four conditions: the stilling basin with sediments, the stilling basin without sediments, the bar-screens blocked and the bar-screens un-blocked. The research findings showed that with the stilling basin not silted up and the bar-screens not blocked, the water discharge of Lao-Nong Weir exceeds the estimated capacity when designed—the maximum complete discharge capacity (Q0) of a single unit of bar-screens reaches about 27 cms; the maximum discharge capacity reaches about 2 Q0; the maximum complete discharge capacity of the two bar-screen units together reaches about 79 cms (2.9 times that of a single unit); and the maximum discharge capacity of the two bar-screen units together is about 93 cms (2 times that of a single unit). In essence, the lower the flow rate, the less the impact of blocked bar-screens and the greater the impact of silted stilling basin on the discharge capacity. In addition, the research findings indicated that whenever Lao-Nong Weir is at its medium-low flow rate (under 100 cms), proper measures should be taken to discharge surplus water for enough water preservation downstream.
36
Huang, Tza-Wei, und 黃則衛. „A Miniaturized Planar Type Reference Electrode Based on a Screen-Printing with Polymer Thin Films“. Thesis, 2008. http://ndltd.ncl.edu.tw/handle/19220128324544490364.
Der volle Inhalt der QuelleAnnotation:
碩士中原大學
電子工程研究所
96
Recently, a rapid determination of different analytically relevant parameters is developed in medical and environmental applications. A simple and miniature sensing instrument is more and more desirable. Typically, an electrochemical sensor can be divided by two major parts, named sensing electrode and reference electrode. Currently, with the trend toward miniaturization, some reports have been proposed to miniaturize sensing electrode. However, conventional reference electrodes are still primarily made of glass or ceramic enclosing an electrolyte solution. Due to the bulk size of the material such as glass or ceramic, the resulting reference electrodes cannot be reduced beyond a certain limit. Moreover, problems such as challenging manufacturing processes, fragile structure and high cost still exist. In this thesis, the main research topics are focused on the manufacture of miniaturized reference electrode. In this thesis, a miniaturized planar type reference is presented, including a screen-printing Ag/AgCl electrode and the protective polymer layers with optimum design parameters. Compare to the conventional reference electrode, the developed reference electrode has several advantages of small size, low-cost, disposable device, and mass-production. Moreover, the developed reference electrode shows low ions sensitivity in various electrolyte solutions. The reference electrode constructed in this thesis was especially suitable for clinical measurement, monitoring the quality of water, food industry and develop biosensor in laboratory.
37
Cherng, Jeng-Wej, und 程正維. „DESIGN OF SELF-CONSTRUCTING TYPE-2 FUZZY NEURAL NETWORK FOR PLATFORM SCREEN DOOR CONTROL SYSTEM“. Thesis, 2011. http://ndltd.ncl.edu.tw/handle/98825185330910076087.
Der volle Inhalt der QuelleAnnotation:
碩士大同大學
電機工程學系(所)
99
Variations in the values of the wind resistance, the friction coefficients of the spring and tensioner, DC motor, cable and other nonlinear dynamics may highly affect the performance of the platform screen door (PSD). A speed control of the PSD is implemented in this paper via an self-constructing type-2 fuzzy neural network (SCT2FNN) controller. The SCT2FNN controller is composed of a type-2 fuzzy neural network (T2FNN) controller, self-constructing learning algorithm and on-line learning algorithm. The T2FNN controller is main controller which computes the pulse-width modulation (PWM) duty of the DC motor to control the PSD. The structure and parameter learning are done automatic and online. The Mahalanobis distance (M-distance) method in the self-constructing learning algorithm is used to determine if the T2FNN rules are generated/eliminated or not. The on-line learning algorithm is based on the back-propagation method to update the parameters (means, standard deviations and weights) of the T2FNN using a delta law. Finally, a PSD speed control system considering wide resistance and friction coefficients is implemented in this paper to compare the other controllers and proposed SCT2FNN controller.
38
Wang, Jiao-Wei, und 王教瑋. „Fabrication of N-Type Silicon Solar Cell with Rear Emitters Formed by Screen-Printed Aluminum“. Thesis, 2017. http://ndltd.ncl.edu.tw/handle/dskk86.
Der volle Inhalt der QuelleAnnotation:
碩士國立清華大學
光電工程研究所
105
Compared with p-type crystalline silicon solar cells, n-type crystalline silicon solar cells can reach better performance because n-type solar cells do not suffer from light-induced degradation and have better tolerance of impurities. Some fabrication processes for n-type silicon solar cells are the same as those for p-type solar cells. Taking the process of anti-reflection layer deposition for example, both types of cells may use the PECVD technique for silicon nitride deposition at the front side. Pyramid formation through alkaline etching to trap light at the front surface is also the same process for both types. However, there are some processes for n-type solar cells that are different from those for p-type solar cells. In this paper, we form emitter by co-firing screen-printed aluminum at the rear side of an n-type crystalline silicon. First, by comparing the performance of different co-firing parameters, we find the best firing temperature in forming rear emitters. Then we use the same temperature for co-firing the cells with higher wafer resistivity. In the study, we also investigate the cell performance as a passivation layer of Al2¬O3 is formed at the rear side.
39
郭建宏. „Effects of Screen Type, Polarity, and Target/Background Color Combination on Visual Acuity and Subjective Preference“. Thesis, 2001. http://ndltd.ncl.edu.tw/handle/58585100731159966407.
Der volle Inhalt der QuelleAnnotation:
碩士國立臺灣科技大學
工業管理系
89
This study investigated the effects of screen type, polarity, and target/background color combination on visual acuity and subjective preference. And the regression equations for visual acuity and subjective preference were constructed. The results showed that： （1）Screen type significantly affected visual acuity, and the visual acuity of TFT-LCD was better than that of CRT. Screen type had no significant effect on subjective preference. （2）The positive presentation had a little better than negative presentation on visual acuity and subjective preference, but they had no significant effect. It could always obtain a good visual performance on polarity by using a suitable color combination, so color combination was more important than polarity.（3）Target color had no significant effect on visual acuity, but did on subjective preference. The warm target colors were favorable for subjective preference. （4）Background color also had no significant effect on visual acuity, but did on subjective preference. The cool background colors were favorable for subjective preference.（5）Correlation analysis showed that the two regression equations derived from this study were better than other models.
40
SHIH, PO-CHENG, und 施柏丞. „Mechanics Analysis of Ball Screw Type Elevator“. Thesis, 2019. http://ndltd.ncl.edu.tw/handle/stvr97.
Der volle Inhalt der QuelleAnnotation:
碩士國立雲林科技大學
機械工程系
107
Since 1993, Taiwan has become an aging society. In the future, it is expected to become a super-aging society in 2026. For elder people with stairs in their homes, it will be increasingly inconvenient. Therefore, elevators are more important in home life. In recent years, European countries and the United States have developed home elevator technology. Japan also began to have the small elevator standard. This research focus the small elevator driven by ball screw that under the standard of American Society of Mechanical Engineers (ASME) specification. Such as: maximum load, operating speed, etc. For the stress and deformation of the components in the ball screw type elevator, this research do mechanical analysis to see the changes of stress during running test. The products of the ball screw and linear guideway are based on the domestic manufacturers. The rest of parts are purchased on the market. Afterward the finite element analysis (Ansys Workbench) is used to do the elevator static simulation and use Adams software to do movement simulation. Whether or not the components in this research are in the allowable stress. It is determined by standard of ASME whether there is any possibility of damage. According to the safety factor of every component, the simulated stress values in this research are all within the allowable stress. Therefore, every component will not be damaged.
41
Chen, Yen-Po, und 陳彥博. „Fabrication of Selective Emitter Type Single-Crystalline Silicon Solar Cells by Using Screen Printing and Chemical Etching Method“. Thesis, 2012. http://ndltd.ncl.edu.tw/handle/50713691952998331093.
Der volle Inhalt der Quelle
42
Lee, Chi-Ming, und 李啟銘. „Application of yeast two-hybrid screen to identify P/Q-type calcium channel-interacting proteins in rat brain“. Thesis, 2012. http://ndltd.ncl.edu.tw/handle/23511571449086176224.
Der volle Inhalt der QuelleAnnotation:
碩士國立臺灣大學
生理學研究所
101
P/Q type voltage-gated Ca2+ channels are composed of pore-forming α1A subunit and auxiliary α2δ and β subunits. In neurons, P/Q type voltage-gated Ca2+ channels are primarily located at dendrite and axon terminal, the neurophysiological role of P/Q type voltage-gated Ca2+ channels may include the neuronal excitability and modulation of synaptic transmission. Mutations in P/Q type voltage-gated Ca2+ channels are associated with a variety of hereditary neuropathy, the detail mechanisms of which remain unclear. P/Q type voltage-gated Ca2+ channels were regulated by SNARE proteins, G proteins and calmodulin (CaM). In this study, we aim to apply the cytoplasma C-terminus of P/Q type voltage-gated Ca2+ channels as the bait for yeast two-hybrid screening to search for novel P/Q type voltage-gated Ca2+ channels interacting proteins. 156 prey clones were identified after screening a rat brain cDNA library. By DNA sequencing and eliminating the clones with incorrect reading frames, we have obtained 67 positive clones. 10 potential candidates from 67 positive clones were chosen for further characterization. X-gal assays and leucine requirement tests were performed to reconfirm the interaction between P/Q type voltage-gated Ca2+ channels and potential candidate proteins. All of the 10 candidate proteins showed blue patches on blue and/white tests and were able to grow on leucine-deficient plates, suggesting that these clones may indeed interact with P/Q type voltage-gated Ca2+ channels. We performed GST pull-down assay, and found the 7 of the 10 candidate proteins have positive reaction. We performed Co-IP assay, so far, we test 3 of these candidate proteins and found the 2 of the 3 candidate proteins have positive reaction. And then, we performed immunofluorescence microscopy imaging to observe subcelluar lococaliztion of these candidate proteins. We can find which candidate protein might colocolize with P/Q-type calcium channels. We expect to take electrophysiological experiments prove P/Q-type calcium channel properties, in addition to prove their interactions with different biochemical experiments. We hope to better understand about physiological mechanism of the P/Q-type calcium channels and the related hereditary neurodegenerative disease.
43
GAO, YI-SHUN, und 高易瞬. „Computer screen showing the position of the signal, the impact of the type and timing of short-term memory“. Thesis, 2014. http://ndltd.ncl.edu.tw/handle/87204521083000655545.
Der volle Inhalt der QuelleAnnotation:
碩士東南科技大學
工業管理研究所
102
This article studies the computer screen position, the signal presents the type and the signal presents the time to the short-term memory influence, this experimental study uses three factor variance analysis, when watches the computer screen signal in view of the people, the signal type, the screen position and present the time whether has the influence to the short-term memory, in the research recollects the signal accuracy to take this experiment de-pends on the variable. The findings discovered that, the time length and the signal type are different, may have the remarkable influence to the short-term memory, appears as for the signal in where cannot see the remarkable result, in the signal is also highest by English signal recollection accuracy, next is traditional Chinese, is the graph once more, between three independent variable corre-lations are not remarkable to the short-term memory recollection accuracy affect.
44
何晉欽. „Design of variable-pitch-lead-screw type steering mechanisms“. Thesis, 2001. http://ndltd.ncl.edu.tw/handle/57679238279911738943.
Der volle Inhalt der Quelle
45
Mund, Julie Ann. „A Synthetic Lethal shRNA Screen and Genetic Proof of Concept Identifies RAC1 as a Novel Target to Disrupt Plexiform Neurofibroma Formation“. Diss., 2019. http://hdl.handle.net/1805/21933.
Der volle Inhalt der QuelleAnnotation:
Indiana University-Purdue University Indianapolis (IUPUI)Neurofibromatosis Type 1 (NF1) is a highly penetrant autosomal dominant genetic disorder where mutations in the tumor suppressor gene NF1 leads to decreased neurofibromin. The most debilitating manifestation is the presence of complex multilineage Schwann cell-derived plexiform neurofibromas (PN). Historically, little clinical success has been achieved targeting PN through surgery or chemotherapies. I performed an shRNA library screen of patient-derived Schwann cell lines to identify novel therapeutic targets to disrupt PN formation and progression. An shRNA library screen of human kinases and Rho-GTPases was performed in NF1-/- and paired NF1 competent immortalized Schwann cell lines. Following sequencing, candidates were identified. We previously developed a novel mouse model of NF1 wherein a neural crest specific Postncre targeted loxp-flanked Nf1 that replicated the PN found in patients. Additional cohorts of mice were generated with biallelic deletion of Rac1 (Nf1f/fRac1f/f Postn-Cre+; DKO ). Mice were aged for 9 months and peripheral nerves were harvested and fixed in formalin. Peripheral nerve size was measured and tumors were identified through blinded analysis of hematoxylin and eosin and Masson’s Trichrome (collagen) stained slides. Rho family members, including RAC1, were identified as candidates through an shRNA library screen. Genetic disruption of Rac1 in the Schwann cell lineage resulted in the prevention of tumor formation in DKO mice, as observed by peripheral nerve size and histological analysis. I observed an average of 14.8 +/- 2.65 tumors per mouse in the Nf1f/f Postnviii Cre+ cohort compared to 0 tumors in the DKO (p<0.0001). Following an shRNA library screen, RAC1 was identified as a candidate to modulate PN formation. Biallelic deletion of Rac1 in vivo prevented PN formation. I demonstrate that a candidate identified in an shRNA library screen can translate to an biological effect in a mouse model of PN.
46
Chu, Hsien-Min, und 朱涎民. „Improved Photovoltaic Characteristics of Screen-Printed N-Type Mono-Crystalline Silicon Solar Cells by Alkali Etching and Various Front Electrodes“. Thesis, 2014. http://ndltd.ncl.edu.tw/handle/5e465y.
Der volle Inhalt der QuelleAnnotation:
碩士國立虎尾科技大學
光電與材料科技研究所
102
The effects of KOH alkali etching and various electrode pastes on photovoltaic characteristics of screen-printed N-type mono-crystalline silicon solar cells (SPMSSCs) were presented. Firstly, the sheet resistances of the emitters in SPMSSCs were modified by KOH alkali etching after ohmic contact formation in the rear side of SPMSSCs. Furthermore, the P-type emitter in SPMSSCs can be obtained by the boron diffusion paste. The results reveal that compared with the SPMSSC without KOH alkali etching, the achievement of an conversion efficiency (CE) improvement of more than 3% absolute in the SPMSSC with KOH alkali etching was explored. Moreover, to investigate the effects of both front and rear electrodes on electrical characteristics of SPMSSCs, the Al, Ag, AgAl and AgB pastes were used as the front electrodes. On the other hand, the Ag pastes were used as the rear electrodes. The CE of 16.3% can be achieved by AgAl(6%) and Ag pastes as the front and rear electrode, respectively. The enhanced mechanisms could be due to the formation of front surface field (FSF) by the Al doped emitter and low bulk resistivity of Ag film for AgAl paste with around 4-6% Al doping.
47
Tseng, Po-lung, und 曾柏龍. „Design and Realization of Ball Screw Type Elevator Control System“. Thesis, 2011. http://ndltd.ncl.edu.tw/handle/31027247295428625300.
Der volle Inhalt der QuelleAnnotation:
碩士逢甲大學
資訊電機工程碩士在職專班
100
Since AD 2000 birthrate dropped 30% sharply in Taiwan. Low birthrate bring huge impact on Taiwan to individuals, industry and society, cause great social pattern change in Taiwan, aged people''s home life will be difficult in multi floor house. Elevator in the home life older people become of more and more important. In the present and the future and playing a useful role. Advanced countries such as Europe, America and Japan. Has been vigorously promoting small elevator, in recent years. Ball screw type elevator is a new framework for the development of small elevator. The purpose of this study was to reach for the completion of a ball screw type elevator control system. And compare the effects of different control modes of operation. Find out the control models for ball screw type of the elevator structure. Make the ball screw type home elevator is more practical.
48
Hao-Wei, Ting, und 丁顥瑋. „Analysis of Micro-type Circular Rod Screw Thread Machining Process“. Thesis, 2018. http://ndltd.ncl.edu.tw/handle/wwux7w.
Der volle Inhalt der QuelleAnnotation:
碩士國立勤益科技大學
機械工程系
106
This study aims to analyze the micro circular bar screw thread machining process with different outer diameters (Ø1.9mm, Ø1.94mm, Ø2mm), pitches (0.25mm, 0.4mm) and friction factors (0.1, 0.2, 0.3, 0.5, 0.7). The microscopic material parameters modified through the factor of proportionality are proceeded finite element analysis to realize the effects of outer diameter, pitch and friction factor on the micro screw thread machining process. In this study, full integration and shape function derived from three-dimension tetrahedral element with four nodes are coupled into the stiffness matrix for finite element analysis. This study focuses on the simulation of all forming resume information, stress/strain distribution, and profiles analysis in the micro circular bar screw thread machining process, and design a micro circular bar screw thread machining tool for the processing experiment of SUS304, which is further compared with the simulation result to verify the reliability of this analysis program. This study analyzes the difference between conventional material parameters and the material parameters after the micro size modification. The results are summarized as follows. The simulation results of the modified material parameters show that the maximum principal stress has a trend to increase with increasing pitch. The material parameters before and after modification have no significant difference in the maximum principal strain. When the friction factor is changed in the micro circular bar thread process, the torque and stress/strain increase with the increase of friction factor.
49
莊志偉. „Study on the Milling of Screw Type Vacuum Pump Rotor“. Thesis, 1999. http://ndltd.ncl.edu.tw/handle/49156625292265687951.
Der volle Inhalt der QuelleAnnotation:
碩士國立成功大學
機械工程學系
87
In this thesis, the four-axis and five-axis milling methods are developed for machining the screw type vacuum pump rotor which is designed using the ruled surface method. First, the surface equation represented in Plucker coordinate system is derived from the geometric parameter data of the rotor. The cutter location data are then generated for both four-axis and five-axis milling methods through homogeneous coordinate transformation between the machine and rotor coordinates . By integrating the structure transformation matrix of the machine tool with the cutter location data, the equation of the NC data needed for the four-axis and five-axis milling is established. Finally, based on the NC data equation and cutter location data, the post-processor routine is constructed to generate the NC data. Through milling simulation using VERICUT software and experiment with AL 6061-T6 material, the four-axis and five-axis milling methods presented in this thesis are validated for the machining of the screw type vacuum pump rotor.
50
Lin, Chin-Chiuan, und 林清泉. „Effects of Screen Type, Ambient Illumination, and Text/Background Color Combination on Visual Performance, Subjective preference, and Visual Fatigue of VDT Work“. Thesis, 2000. http://ndltd.ncl.edu.tw/handle/02225434583448797866.
Der volle Inhalt der QuelleAnnotation:
博士國立臺灣科技大學
工業管理系
89
Two experiments were conducted to compare CRT and TFT-LCD under various working conditions in this study. The first experiment investigated the effects of screen type, ambient illumination, and target/background color combination on visual identification performance and subjective preference. Results showed that screen type significantly affected visual performance. Subjects performed better with the thin film transistor liquid crystal display (TFT-LCD) than with the cathode ray tube (CRT). Visual performance was better under 450 lx ambient illumination, versus, 200 lx. Color combination also significantly affected visual performance, with blue letters on a yellow background resulting in the best performance and purple-on-red the worst. Subjective preference was significantly affected by color combination. Blue-on-yellow resulted in the greatest subjective preference, while purple-on-red the worst. Thus, subjective preference and visual performance for color combinations were related. The second experiment investigated the effects of screen type, polarity, and color combination on long time reading performance, subjective visual fatigue, and viewing distance. Results indicated that neither reading performance nor subjective visual fatigue was significantly affected by screen type, polarity, or color combination. Viewing distance was significantly affected by polarity, with positive presentation resulting in longer viewing distance than negative presentation. Subjective visual fatigue was significantly related to viewing distance. Subjects with longer viewing distance generally experienced less subjective visual fatigue. In summary, for VDT work, the TFT-LCD screen seemed to be the preferred technology, positive presentation more appropriate than negative presentation, and unsaturated color better than saturated color.