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The Global ETD Search service is a free service for researchers
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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.
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Showing 1 to 9 of 9 (0.042 seconds)| 1 |
Towards closed-loop nanopatterning: quantifying ink dynamics in dip-pen nanolithographyFarmakidis, Nikolaos 05 November 2016 (has links)
Dip-pen nanolithography (DPN) is a scanning probe microscopy-based nanofabrication
method that relies on a fluid-coated atomic force microscope probe for the
deposition of material on a substrate with nanometer-scale resolution. The ability to
tailor the structure and chemical composition of materials at the nanometer length
scale is enabling in elds ranging from medical diagnostics to nano-electronics. While
DPN is among the highest resolution additive manufacturing techniques to date, the
conguration of ink on the probe and the process of ink transport are poorly understood.
Specically, the inking and patterning procedures are susceptible to variations
in the ambient environmental conditions and currently not all aspects of the processes
are reliably controlled. Thus, a key challenge barring the widespread adoption
of DPN beyond a research tool is reproducibility. We hypothesize that closed-loop
control over the inking and patterning process could address this irreproducibility,
however techniques to monitor the quantity and concentration of ink on the tip of the
probe have not been yet developed. Here, we study the mechanics of atomic force microscope
(AFM) probes throughout the inking and patterning process to understand
if the behavior of the ink can be studied in situ. In particular, we develop an approach
for conning ink to the tip of an AFM probe, which is critical for reliable patterning
and modeling the mechanics of the probe. Then, we nd that the quantity of ink
on an AFM probe can be determined in situ by observing the shift in the natural
frequency of the probe. Finally, we show that this method allows for the observation
and quantication of the ink deposited on a substrate, in real time. Collectively,
these approaches lay the groundwork for a closed-loop implementation of DPN in
which the inking and patterning processes are performed with drastically improved
reliability. Given that these techniques are easily implemented on any commercial
AFM, we expect that they could lead to new applications in the study of nanoscale
soft materials. / 2017-11-04T00:00:00Z
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Nástroj pro podporu managementu projektů / Tool for Projects Management SupportVlk, Jakub January 2014 (has links)
This thesis focuses on support tool for project management. The introduction describes the areas of knowledge management according to current standards of PMI. The focus is placed on the inputs and outputs of each process of all knowledge areas. To demonstrate all the inputs and outputs of processes in order to specify system requirements for transformation the illustrations have been attached. The following chapter investigates the system itself, the process of transformation of inputs to outputs. First of all the requirements specification is created. Requirements are focused on functionality, characteristics and expectations of users. At the selected process in the proposal, in agreement with the supervisor, three methods are selected. Transformation of inputs to output is described in these methods. The system should be designed with regard to the appropriate visualization of the outputs of these three methods. The thorough analysis of the results obtained is presented in the final chapter along with the students' personal contribution and the possible future development.
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Tissue Nanotransfection Strategies for the Treatment of Diabetic Neuropathy and Volumetric Muscle LossClark, Andrew January 2020 (has links)
No description available.
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Färgstyrning av Kodak Nexpress på Digital Printing NetworkMöller, Jesper January 2009 (has links)
Det här examensarbetet berör ämnet färgstyrning inom digitaltryck. Grundprincipen medfärgstyrning är att få hela den grafiska produktionskedjan att resultera i en förutsägbar och korrektslutprodukt. Den här styrningen sker i huvudsak med hjälp av ICC-profiler.Syftet med arbetet var att hjälpa företaget dpn att ta fram ett väl fungerande arbetsflöde för derastvå Kodak digitalpressar. Företaget ville dels få en så bra färgmatchning mellan de bådatryckpressarna som möjligt, och dels få en så bra matchning mot gällande standardvärden föroffsettryck som möjligt. Dessutom syftade arbetet till att utveckla min egen kunskap kring arbetetmed färgstyrning.Arbetet utfördes genom instudering av relevant teori i ämnet, vilken sedan applicerades på detpraktiska arbetet. Det praktiska arbetet bestod främst i att trycka testkartor som mättes upp och lågtill grund för skapande av ICC-profiler.Arbetet visade sig ge ett positivt resultat. Mätningar gjordes dels innan arbetet påbörjades för attkontrollera hur stor färgavvikelsen var vid det tillfället. Efter skapande och applicering av de nyaprofilerna visade sig färgavvikelsen ha minskat, både sinsemellan de båda tryckpressarna och motgällande standard. Avvikelsen hamnade under de målvärden företaget satt upp på förhand, menlämnade samtidigt utrymme för ytterligare förbättringar på sina ställen.SlutsatserRapporten visar att målsättningen att få de båda tryckpressarna på företaget att trycka med enfärgavvikelse under de på förhand uppsatta värdena kunde uppnås med god marginal. Vidarekonstaterades också att målet att få de båda tryckpressarna att simulera mot standardvärden föroffsettryck kunde uppnås, med undantag för några enstaka färgvärden. / Color management of Kodak Nexpress on Digital Printing NetworkThis thesis concerns the subject of color management in digital printing. The basic principle ofcolor management is to get the entire graphic production to result in a predictable and accurate endproduct. This control is mainly made by the use of ICC profiles.The purpose of this work was to help the company dpn to produce a well-functioning workflow fortheir two Kodak digital presses. The company wanted to get as good color matching between thetwo printing machines as possible, and get a good match with the existing standard values for offsetprinting as possible.The work was carried out by studying of relevant theory on the subject, which then was applied tothe practical work. The practical work consisted mainly of printing test charts, which was measuredand was the basis for the creation of the ICC profiles.The work proved to give a positive result. Measurements were made before the work began tocontrol how much color difference was at the time. After the creation and application of the newprofiles it was shown that color deviation have declined, both between the two printing presses andwith the current standard. Deviation fell below the targets the company had set up in advance, butdid allow for further improvements in their places.ConclusionsThe report shows that the objective of the two Kodak Nexpress to print with a color differenceunder the pre-determined values could be achieved with good margin. Moreover, it was found thatthe objective of the two Kodak Nexpress to simulate the default values for offset printing wasachieved, with the exception of a few color values.
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Thermal Bimorph Micro-Cantilever Based Nano-Calorimeter for Sensing of Energetic MaterialsKang, Seokwon 2012 May 1900 (has links)
The objective of this study is to develop a robust portable nano-calorimeter sensor for detection of energetic materials, primarily explosives, combustible materials and propellants. A micro-cantilever sensor array is actuated thermally using bi-morph structure consisting of gold (Au: 400 nm) and silicon nitride (Si3N4: 600 nm) thin film layers of sub-micron thickness. An array of micro-heaters is integrated with the microcantilevers at their base. On electrically activating the micro-heaters at different actuation currents the microcantilevers undergo thermo-mechanical deformation, due to differential coefficient of thermal expansion. This deformation is tracked by monitoring the reflected ray from a laser illuminating the individual microcantilevers (i.e., using the optical lever principle). In the presence of explosive vapors, the change in bending response of microcantilever is affected by the induced thermal stresses arising from temperature changes due to adsorption and combustion reactions (catalyzed by the gold surface). A parametric study was performed for investigating the optimum values by varying the thickness and length in parallel with the heater power since the sensor sensitivity is enhanced by the optimum geometry as well as operating conditions for the sensor (e.g., temperature distribution within the microcantilever, power supply, concentration of the analyte, etc.). Also, for the geometry present in this study the nano-coatings of high thermal conductivity materials (e.g., Carbon Nanotubes: CNTs) over the microcantilever surface enables maximizing the thermally induced stress, which results in the enhancement of sensor sensitivity. For this purpose, CNTs are synthesized by post-growth method over the metal (e.g., Palladium Chloride: PdCl2) catalyst arrays pre-deposited by Dip-Pen Nanolithography (DPN) technique. The threshold current for differential actuation of the microcantilevers is correlated with the catalytic activity of a particular explosive (combustible vapor) over the metal (Au) catalysts and the corresponding vapor pressure. Numerical modeling is also explored to study the variation of temperature, species concentration and deflection of individual microcantilevers as a function of actuation current. Joule-heating in the resistive heating elements was coupled with the gaseous combustion at the heated surface to obtain the temperature profile and therefore the deflection of a microcantilever by calculating the thermally induced stress and strain relationship. The sensitivity of the threshold current of the sensor that is used for the specific detection and identification of individual explosives samples - is predicted to depend on the chemical kinetics and the vapor pressure. The simulation results showed similar trends with the experimental results for monitoring the bending response of the microcantilever sensors to explosive vapors (e.g., Acetone and 2-Propanol) as a function of the actuation current.
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Actions of Selective Estrogenic Drugs Implanted Into the Medial Amygdala on Male Rat Mating BehaviorDunigan, Anna I 04 April 2012 (has links)
Estrogen stimulation of the medial amygdala (MEA) of the brain promotes male rat mating behavior. However, selective stimulation of either of the estrogen receptor subtypes found in the MEA (ERα or ERβ) does not support mating behavior. We tested the hypothesis that dual stimulation of ERα and ERβ is required to activate estrogen-dependant neural circuits in the MEA responsible for mating by local treatment of MEA with a combination of selective estrogenic agonists: propyl pyrazole triol (PPT, an ERα agonist ) and diarylpropionitrile (DPN, an ERβ agonist) administered to castrated, DHT maintained male rats. Estradiol (E2) or cholesterol (Chol) MEA implants served as positive and negative controls respectively. The animals receiving a mixture of PPT and DPN into the MEA displayed higher levels of mating behavior than the Chol treated animals but lower levels of mating behavior than the E2 treated animals.
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Food, friends and foes: estrogens and social behaviour in mice.Clipperton Allen, Amy Elizabeth 13 January 2012 (has links)
This thesis investigates estrogens' modulation of three aspects of social cognition (aggression and agonistic behaviour, social learning, and social recognition). Sex-typical agonistic behaviour (males: overt attacks, females: more subtle dominance behaviours) was increased in gonadectomized mice by estrogen receptor alpha (ERα) agonist 1,3,5-tris(4-hydroxyphenyl)-4-propyl-1H-pyrazole (PPT), while non-overt agonistic behaviour was increased in male and female gonadally intact mice by ERβ agonist 7-Bromo-2-(4-hydroxyphenyl)-1,3-benzoxazol-5-ol (WAY-200070). Estrogens also affected the social transmission of food preferences (STFP). Acute estrogen and ERβ agonists WAY-200070 and 2,3-bis(4-hydroxyphenyl)propionitrile (DPN) prolonged the preference for the demonstrated food when administered pre-acquisition, likely by affecting motivation or the nature of the social interaction, while acute PPT blocked the STFP. All mice receiving any of the three treatments chronically showed a prolonged demonstrated food preference, suggesting a loss of ER specificity. Individual differences in social recognition may relate to increased oxytocin (OT) and vasopressin (AVP) mRNA, and ERα and ERβ gene activation, in the medial preoptic area, and decreased mRNA for ERs, OT receptor (OTR), AVP and AVP receptors 1a and 1b in the lateral amygdala. Additionally, dorsolateral septum ERs, progesterone receptor, and OTR may relate to social interest without affecting social recognition. Our and others' results suggest that estrogens, OT and AVP are all involved in social behaviours and mediate social recognition, social learning, social interactions, and aggression. ERs differently modulate the two types of social learning investigated here: ERα is critical for social recognition, but impairs social learning, while ERβ is less important in social recognition, and prolongs the demonstrated food preference in the STFP. This may be due to differences in receptor brain distributions or in downstream neurochemical systems that mediate these behaviours. The results of this thesis suggest that estrogens, through the various systems they modulate, have a key role to play in social behaviour. Further investigations of how estrogens effect change in these systems at the molecular and cellular level, as well as the critical brain areas and downstream effectors involved in these complex behaviours, are needed, and could contribute to therapeutic interventions in socially-based, sexually dimorphic disorders, like the autism spectrum disorders, and women receiving hormone replacement therapy for negative peri- or post-menopausal symptoms. / National Science and Engineering Research Council (PGS-D, CGS-M)
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La conception collaborative avec les fournisseurs : proposition d'une méthode d'analyse par les dysfonctionnements / Measuring benefits of inter organisational collaborations and implementing necessary interface processPersonnier, Hélène 15 October 2013 (has links)
Ce travail de thèse a pour thème le co-développement de nouveau produit avec les fournisseurs.Nous proposons une méthode d’analyse des dysfonctionnements liés à ce type de conceptiondite « collaborative » qui permet d’en améliorer la pratique. Ce travail s’appuie sur des études decas réalisées au sein de l’entreprise Somfy, des interviews menées au sein de 10 entreprises etune étude quantitative menée avec l’Université de Twente. A partir de la littérature et des étudesde cas, nous proposons une liste des dysfonctionnements puis une classification de ces derniersen 5 classes selon le cycle de vie de la collaboration client/fournisseur. Puis, une analysequantitative d’impact des dysfonctionnements sur la performance projet via une enquête estproposée pour généraliser les résultats des études de cas. Le résultat final de cette thèse est unoutil d’analyse de risques en co-développement avec les fournisseurs développé avecl’entreprise Somfy et inspiré de la démarche AMDEC. Cet outil permet, en début de projet de codéveloppement,d’identifier les dysfonctionnements potentiels les plus critiques de façon àmettre en place un plan d’action adapté. / This thesis is focused on collaborative development of new products with suppliers. A method toanalyze failures linked to this type of development is proposed and enables to improve thispractice. This work is based on case studies carried out at Somfy Company, on interviews carriedout with 10 companies and on a quantitative study carried out with the University of Twente.From a literature review and our case studies, a list of failures is proposed followed by a failuresclassification in 5 classes following the customer/supplier collaboration lifecycle. Then, aquantitative impact analysis of the failures on the project performance via a survey is proposedto generalize the case studies’ results. The final result of this thesis is a risk analysis tool appliedto collaborative development with suppliers developed with Somfy and inspired by the FMEAapproach. This tool enables, at the beginning of a collaborative development project, to identifythe most critical potential failures in order to set up an adapted action plan.
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Nanolithography on thin films using heated atomic force microscope cantileversSaxena, Shubham 01 November 2006 (has links)
Nanotechnology is expected to play a major role in many technology areas including electronics, materials, and defense. One of the most popular tools for nanoscale surface analysis is the atomic force microscope (AFM). AFM can be used for surface manipulation along with surface imaging.
The primary motivation for this research is to demonstrate AFM-based lithography on thin films using cantilevers with integrated heaters. These thermal cantilevers can control the temperature at the end of the tip, and hence they can be used for local in-situ thermal analysis. This research directly addresses applications like nanoscale electrical circuit fabrication/repair and thermal analysis of thin-films. In this study, an investigation was performed on two thin-film materials. One of them is co-polycarbonate, a variant of a polymer named polycarbonate, and the other is an energetic material called pentaerythritol tetranitrate (PETN).
Experimental methods involved in the lithography process are discussed, and the results of lithographic experiments performed on co-polycarbonate and PETN are reported. Effects of dominant parameters during lithography experiments like time, temperature, and force are investigated. Results of simulation of the interface temperature between thermal cantilever tip and thin film surface, at the beginning of the lithography process, are also reported.
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