To see the other types of publications on this topic, follow the link: Active probes.
Dissertations / Theses on the topic 'Active probes'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Active probes.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Walpole, C. S. J. "Active site probes for bacterial luciferase." Thesis, University of Sussex, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356510.
Full text
2
Sun, Zhenning. "Studies on fluorescent probes for the specific detection of reactive oxygen species and reactive nitrogen species in living cells." View the Table of Contents & Abstract, 2006. http://sunzi.lib.hku.hk/hkuto/record/B36845395.
Full text
3
Torun, Hamdi. "Micromachined membrane-based active probes for biomolecular force spectroscopy." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/39638.
Full textAbstract:
Atomic force microscope (AFM) is an invaluable tool for measurement of pico-Newton to nano-Newton levels of interaction forces in liquid. As such, it is widely used to measure single-molecular interaction forces through dynamic force spectroscopy. In this technique, the interaction force spectra between a specimen on the sharp tip of the cantilever and another specimen on the substrate is measured by repeatedly moving the cantilever in and out of contact with the substrate. By varying the loading rate and measuring the bond rupture force or bond lifetime give researchers information about the strength and dissociation rates of non-covalent bonds, which in turn determines the energy barriers to overcome. Commercially available cantilevers can resolve interaction forces as low as 5 pN with 1 kHz bandwidth in fluid. This resolution can be improved to 1 pN by using smaller cantilevers at the expense of microfabrication constraints and sophisticated detection systems. The pulling speed of the cantilever, which determines the loading rate of the bonds, is limited to the point where the hydrodynamic drag force becomes comparable to the level of the molecular interaction force. This level is around 10 um/s for most cantilevers while higher pulling speeds are required for complete understanding of force spectra. Thus, novel actuators that allow higher loading rates with minimal hydrodynamic drag forces on the cantilevers, and fast, sensitive force sensors with simple detection systems are highly desirable.
This dissertation presents the research efforts for the development of membrane-based active probe structures with electrostatic actuation and integrated diffraction-based optical interferometric force detection for single-molecular force measurements. Design, microfabrication and characterization of the probes are explained in detail. A setup including optics and electronics for experimental characterization and biological experiments with the probes membranes is also presented. Finally, biological experiments are included in this dissertation.
The "active" nature of the probe is because of the integrated, parallel-plate type electrostatic actuator. The actuation range of the membrane is controlled with the gap height between the membrane and the substrate. Within this range it is possible to actuate the membrane fast, with a speed limited by the membrane dynamics with negligible hydrodynamic drag. Actuating these membrane probes and using a cantilever coupled to the membrane, fast pulling experiments with an order of magnitude faster than achieved by regular AFM systems are demonstrated.
The displacement noise spectral density for the probe was measured to be below 10 fm/rtHz for frequencies as low as 3 Hz with differential readout scheme. This noise floor provides a force sensitivity of 0.3 - 3 pN with 1 kHz bandwidth using membranes with spring constants of 1 - 10 N/m. This low inherent noise has a potential to probe wide range of biomolecules. The probes have been demonstrated for fast-pulling and high-resolution force sensing. Feasibility for high throughput parallel operation has been explored. Unique capabilities of the probes such as electrostatic spring constant tuning and thermal drift cancellation in AFM are also presented in this dissertation.
4
Schrag, Michael L. "Development of active site directed probes for cytochrome P450 /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/8153.
Full text
5
Shelton, Thomas Earl. "Small Phosphomonoesters as Probes of Protein-Tyrosine Phosphatase Active Sites." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/44898.
Full textAbstract:
I evaluated the potential of isomers of the low molecular weight phosphomonoester naphthyl phosphate as general diagnostic substrates for differentiating between two families of protein phosphatases: the protein-tyrosine phosphatases [PTPs] and the dual-specificity protein phosphatases [DSPs]. Three PTPs, PTP-1B, Tc-PTPa, and PTP-H1, and three DSPs, Cdc-14, VHR, and IphP, were challenged in vitro with alpha-naphthyl phosphate and beta-naphthyl phosphate. Both the DSPs and PTPs readily hydrolyzed beta-naphthyl phosphate. As expected, the DSPs also hydrolyzed alpha-naphthyl phosphate at rates comparable to beta-naphthyl phosphate and two of the PTPs, PTP-1B and Tc-PTPa, hydrolyzed alpha-naphthyl phosphate at a rate one-tenth that of beta-naphthyl phosphate. However, PTP-H1 hydrolyzed both alpha- and beta- naphthyl phosphate at nearly equal rates. Intriguingly, when challenged with radiolabeled phosphoproteins, PTP-H1 was markedly less stringent, by a factor of 40- to 200- fold, than PTP-1B or Tc-PTPa in its selectivity for [32P]phosphotyrosyl- over [32P]phosphoseryl- proteins in vitro.
The DSPs and PTPs listed above also were challenged in vitro with free phosphoserine. Each displayed little or no activity towards free phosphoserine. However, the addition of a hydrophobic "handle" to form N-(cyclohexane carboxyl)-O-phospho-L-serine produced a derivative that was hydrolyzed by IphP at rates comparable to that of the avid substrates p-nitrophenyl phosphate and beta-naphthyl phosphate. VHR also hydrolyzed N-(cyclohexane carboxyl)-O-phospho-L-serine, though at a lower rate than IphP. Cdc14 displayed little activity towards N-(cyclohexane carboxyl)-O-phospho-L-serine.
The active site of VHR was mapped and amino acid residues potentially involved in binding N-(cyclohexane carboxyl)-O-phospho-L-serine were identified. The amino acid sequence of VHR was aligned with the amino acid sequences of IphP and Cdc14 to identify the nature of the corresponding residues in IphP and Cdcd14.
Low molecular weight phosphomonoesters have proven to be effective in vitro indicators of protein phosphatase activity. They also have shown potential as diagnostic substrates for specific subclasses of protein phosphatases. However, neither alpha- and beta- naphthyl phosphate nor N-(cyclohexane carboxyl)-O-phospho-L-serine proved to be universal discriminatory substrates for the functional subgroups within the family of protein-tyrosine phosphatases. Indeed, the probability of identifying such a substrate would appear to be relatively low.
Master of Science
6
Meier, Jordan Leslie. "Synthetic active site probes for PKS and NRPS biosynthetic enzymes." Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p3359523.
Full textAbstract:
Thesis (Ph. D.)--University of California, San Diego, 2009.Title from first page of PDF file (viewed July 7, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
7
Peng, Tao, and 彭濤. "Rhodol fluorophores and fluorescent probes for the detection and imaging of reactive oxygen species." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B41757920.
Full text
8
Peng, Tao. "Rhodol fluorophores and fluorescent probes for the detection and imaging of reactive oxygen species." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B41757920.
Full text
9
Sun, Zhenning, and 孫振宁. "Studies on fluorescent probes for the specific detection of reactive oxygen species and reactive nitrogen species in living cells." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B38677490.
Full text
10
Sharp, Jonathan Oliver. "Synthesis of redox-active probes for the multiplex detection of DNA." Thesis, University of Bath, 2013. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607450.
Full textAbstract:
The research presented within this thesis is concerned with the design and synthesis of redox-active derivatives for the use as labels for DNA probes to be used in a commercial DNA detection assay. Chapter 1: Introduces the area of electrochemical DNA sensing, the methods used and the transducer derivatives used. Also included within this chapter is the discussion on the use of ferrocene and its derivatives as redox-active transducer moieties and their use in a DNA sensing capacity. Chapter 2: Introduces the sponsoring company, Atlas genetics, and the DNA detection assay they are developing for use in a point of care device (POC). The chapter also details the design, synthesis and electrochemical analysis via differential pulse voltammetry of mono-ferrocenyl derivatives for the use as redox-active labels for DNA sensing. The chapter outlines the development of labels containing a variety of functionality as well as possessing a range of oxidation potentials from 95 to 610 mV (vs Ag/AgCl). Chapter 3: Introduces and details the sensitivity issues between mono-ferrocenyl and di-ferrocenyl labels and the effect this could have on the commercial DNA detection assay. Within this chapter there are the details of the design, synthesis and electrochemical analysis via differential pulse voltammetry of the di-ferrocenyl labels. The chapter shows the synthesis of di-ferrocenyl labels containing a wide range of functionality on both the ferrocene core as well as the linker unit, with the labels processing a range of oxidation potentials from 242 to 500 mV (vs. Ag/AgCl). Chapter 4: Discusses the use of the labels designed and synthesised in chapters 2 and 3 in the commercial DNA detection assay developed by Atlas genetics. The development of the labels used as DNA probes in the DNA detection assay and their ability to be used in multiplex DNA detection assays are also described. Demonstrated within this chapter is the use of the labels synthesised in this thesis that give both a duplex between two different probes and also the development of a triplex assay using three different labels to detect for two different target DNAs as well as provide an internal control. Chapter 5: Introduces the synthetic methods towards the synthesis of 2-oxazolines and discusses their use within ring-opening reactions. This chapter details the optimisation of the ring-opening reaction of phenyl-2-oxazoline with a range of carboxylic acid derivatives. The synthesis of a range of 2-oxazolines with various functionality aimed towards the analytical detection of carboxylic acids through the direct conjugation with 2-oxazolines. The ring-opening reaction was found to tolerate a wide range of carboxylic acid derivatives as well as a variety of functionality on the 2-oxazolines such as ferrocene-2-oxazolines and also 3,5 – bis(trifluoromethyl)phenyl-2-oxazoline. The use of ferrocene-2-oxazoline allowed for the electrochemical detection of carboxylic acids and the 3,5 – bis(trifluoromethyl)phenyl-2-oxazoline allows for thedetection of carboxylic acids through its ring-opened form via 19F NMR. These two functionalised 2-oxazolines were used to further analyse the reactions viability as a possible analytical tool for the detection of carboxylic acids by carring out the ring-opening reaction conditions for the detection of ibuprofen from an over the counter tablet.
11
Kim, Hyundae. "Study of a light-gas gun for launching active transient internal probes /." Thesis, Connect to this title online; UW restricted, 2004. http://hdl.handle.net/1773/9997.
Full text
12
Adams, Samuel Joseph. "Luminescent surface-active transition metal complexes as probes for sensing and supramolecular recognition architectures." Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/6346/.
Full textAbstract:
Surface-active luminescent transition metal complexes are synthesised, characterised and successfully attached to gold surfaces for the purposes of micropatterning and biomolecular recognition. Monolayers of ruthenium(II) and iridium(III) complexes bearing disulfide moieties display enchanced lifetimes on gold surfaces compared with aerated solution, and are micropatterned through the use of microcontact printing (µCP). The monolayers also display recognition of serum protein bovine serum albumin through surface plasmon resonance spectroscopy and time-resolved and steady state luminescence spectroscopy. Mixed monolayers of these respective complexes with commercially available surfactants are studied to provide understanding of nanoparticle systems and their involvement in protein interactions. Cyclodextrin containing transition metal complexes are synthesised and characterised for the purposes of supramolecular micropatterning. Mixed monolayers of ruthenium(II) and iridium(III) complexes bearing cyclodextrin moieties can be attached through directed assembly afforded by the µCP technique. Surface-active cyclodextrin containing transition metal complexes are synthesised and characterised for use in selective biomolecular recognition and stepwise assembly. Monolayers of ruthenium(II) and iridium(III) complexes bearing cyclodextrin and disulfide moieties are shown to be luminescent on gold surfaces, and through stepwise assembly afford a selective recognition motif for the protein streptavidin through luminescence and surface plasmon resonance studies. The results indicate the potential of these systems in reusable functional sensing systems.
13
Trumbull, Kari Adele. "Development of an oxidatively-releasable caged biosensor system and application to the release of antioxidants and fluorescent probes /." view abstract or download file of text, 2007. http://proquest.umi.com/pqdweb?did=1324377721&sid=1&Fmt=2&clientId=11238&RQT=309&VName=PQD.
Full textAbstract:
Thesis (Ph. D.)--University of Oregon, 2007.Typescript. Includes vita and abstract. Includes bibliographical references (leaves 137-158). Also available for download via the World Wide Web; free to University of Oregon users.
14
Bogyo, Matthew Steven 1971. "Peptide vinyl sulfones : inhibitors and active site probes for the study of proteasome function in vivo." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/28184.
Full text
15
Soergel, Bjoern. "The kinematic and thermal Sunyaev-Zel'dovich effects as probes of cosmology and astrophysics." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/277657.
Full textAbstract:
A small fraction of cosmic microwave background (CMB) photons scatter off electrons in the ionised gas in collapsed structures. This process, known as the Sunyaev-Zel'dovich effect, is usually broken down into a thermal (tSZ) and a kinematic (kSZ) contribution. While the former is sensitive to the random velocities of the electrons in the hot gas, the latter is sourced by the bulk motion of the entire object. In this thesis I measure the signature of both of these effects by cross-correlating CMB data with different tracers of the large-scale structure. I further study how these effects can be used as probes of cosmology and astrophysics. I first report a statistically significant detection of the kSZ effect. This is achieved by combining a cluster catalogue derived from the first year data of the Dark Energy Survey with CMB temperature maps from the South Pole Telescope. I perform the measurement with a differential statistic that isolates the pairwise kSZ signal, providing the first detection of the large-scale motion of clusters using redshifts derived from photometric data. By fitting the pairwise kSZ signal to a theoretical template, I measure the average central optical depth of the cluster sample. I compare the extracted signal to simulations and find good agreement with respect to the signal-to-noise, the constraint on the optical depth, and the corresponding gas fraction. I next study the potential of the kSZ effect as a probe of cosmology, again focussing on the pairwise method. The main challenge is disentangling the cosmologically interesting mean pairwise velocity from the cluster optical depth and the associated uncertainties on the baryonic physics in clusters. Using the Magneticum cosmological hydrodynamical simulations I calibrate a scaling relation between the amplitude of the tSZ signal and the optical depth. I show that this relation can be used to recover an accurate estimate of the mean pairwise velocity from the kSZ signal, and that this effect can therefore be used as a probe of cosmology. I finally derive constraints on feedback from active galactic nuclei by setting limits on their tSZ signal. By combining all-sky microwave, sub-mm, and far-infrared data from the Planck and AKARI satellites, I break the degeneracy between the tSZ signature and extragalactic dust emission. I test the measurement pipeline with a catalogue of galaxy clusters, finding the expected high-significance tSZ detection together with correlated dust emission. I then measure the tSZ signal of spectroscopically confirmed quasi-stellar objects (QSOs), but obtain only a low-significance hint of a tSZ signature. This analysis leads to a lower mean thermal energy than reported in some previous studies which were contaminated by dust emission. A comparison of these results to hydrodynamical simulations can be used as a probe of QSO host masses.
16
Reese, Raymond Scott. "Self-assembled monolayers of organosulfur compounds on gold incorporating terminal conjugated arenes, redox active probes, and oligonucleotides /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
Full text
17
Hardin, James. "Encapsulation and controlled release of active DNA from uncrosslinked gelatin microspheres." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/43735.
Full textAbstract:
Cancer is a disease that varies dramatically from person to person due to the specifics of the individual's physiology and the source of the cancer. In most cases, the origin of the cancer can be determined but metastasis can lead to tumors anywhere and thus many cancers require treatment of the whole body. Since many of the drugs that are used to treat cancer are toxic to healthy cells as well as cancerous ones, there has been considerable interest in developing ways to convey the drug specifically to the cancer cells with minimal exposure to healthy cells. Colloid drug delivery vehicles have shown considerable progress toward this end, while also reducing degradation of the drug prior to delivery to targeted sites (particularly important for oligonucleotide and protein therapeutics), and controlling release rates.
Toward the end of improved drug delivery, this thesis work investigates the encapsulation of DNA in gelatin microspheres (GMS) and the subsequent temperature controlled release of the encapsulated DNA from these GMS. DNA-loaded GMS were then used as templates for colloidal satellite assemblies and the released DNA was shown to competitively displace the original partner strands of immobilized DNA on the surface of the assemblies. To support these investigations, hybridization of DNA at colloidal surfaces was also investigated using in situ measurements and found to significantly deviate from solution behavior. DNA hybridization is of particular interest as means of controlling the functionality of colloidal structures because it is uniquely reversible and tunable as well as biocompatible. Gelatin was chosen as the encapsulation matrix for its superior biocompatibility, convenient gel to liquid phase transition at ~35 oC, and economical availability.
18
Alawar, Maya. "Micromachining and Packaging of Smart Probes for mmW on-Wafer Measurements." Electronic Thesis or Diss., Université de Lille (2022-....), 2024. http://www.theses.fr/2024ULILN036.
Full textAbstract:
Les technologies silicium avancées, telles que le BiCMOS B55X de STMicroelectronics, visant des fréquences de coupure fT/fmax supérieures à 400 GHz, permettent le développement de circuits dans la gamme 140-220 GHz (bande G). Pour valider ces technologies, les méthodes de caractérisation micro-ondes pour les mesures sur tranche (on-wafer) sont essentielles pour extraire les figures de mérite des transistors, des circuits passifs et des parasites associés. Cependant, les circuits à large bande, tels que les sources de bruit (NS), les récepteurs de bruit et les syntoniseurs d'impédance à ces fréquences sont très peu disponibles sur le marché. Des recherches antérieures ont démontré qu'il est possible d'intégrer directement des fonctions de mesure sur tranche en technologie BiCMOS B55, mais cette approche in-situ ou d'auto-test intégré (BIST, built-in self test) présente des limitations, notamment en termes de surface de silicium et parce que l'instrumentation BIST intégrée ne peut pas être utilisée pour une autre technologie.Cette thèse élargit l'applicabilité de l'instrumentation de mesure au-delà du procédé B55X et vise à réduire les coûts de test en évoluant du BIST aux sondes intelligentes. Cette nouvelle approche se concentre sur l'intégration des fonctions de mesure dans un système compact placé aussi près que possible des sondes de mesure pour des mesures ex-situ.S'appuyant sur des résultats de thèse précédents, la première source de bruit (NS) packagée, basée sur la technologie SiGe BiCMOS 55-nm, a été développée et caractérisée dans deux configurations distinctes. Dans une première approche, les mesures de bruit sur wafer ont permis d'extraire un niveau de rapport de bruit en excès (ENRav) de 37 dB dans la gamme 140-170 GHz. Dans une approche alternative, la NS a été encapsulée dans un boîtier de type split-block avec une terminaison à bride WR5.1 pour une connexion aux sondes passives commerciales, atteignant un niveau ENRav allant jusqu'à 25 dB dans la gamme 140-220 GHz, ce qui correspond à une réduction de 12 dB de l'ENR par rapport aux mesures sur tranche.Pour améliorer ces travaux, un des résultats clés de cette thèse est le développement de sondes Ground-Signal-Ground (GSG) pour les mesures sur tranche, fabriquées par micro-usinage laser femtoseconde avec une résolution comprise entre 5 et 10 µm. Ces sondes, fabriquées à partir d'un substrat de verre Schott AF32 d'une épaisseur de 100 µm et recouvert d'une feuille de nickel de 10 µm, démontrent une durabilité mécanique et des performances électriques améliorées. Alors que les sondes fabriquées à partir d'un substrat de verre sans couche de nickel atteignent la rupture mécanique pour une force de contact de 196 mN, les tests d'atterrissage ont révélé que les sondes en nickel-verre résistaient jusqu'à 667 mN. De plus, ces sondes ont démontré une résistance DC électrique de contact très faible atteignant 0,05 Ω pour une force d'appui supérieure à 6 mN.En outre, cette recherche introduit une nouvelle technologie de substrat qui embarque une puce intégrant une source de bruit amplifiée en technologie B55X sur un interposeur en verre pour réduire les pertes diélectriques et de transition de mode de propagation. Grâce au micro-usinage laser femtoseconde, les interconnexions sont structurées avec précision, permettant l'intégration de la puce NS sur le même substrat que celui utilisé pour fabriquer les pointes de sonde coplanaires, avec l'avantage de simplifier le chemin de propagation du signal. Ce système a atteint un niveau ENRav ajustable jusqu'à 29 dB dans la gamme 140-170 GHz, avec une adaptation d'impédance de sortie meilleure que -12 dB sur l'ensemble de la bande de fréquences.Cette recherche ouvre de nouvelles perspectives pour des sondes actives millimétriques, rentables et évolutives, pour les mesures sur trancheAdvanced silicon technologies, such as BiCMOS B55X from STMicroelectronics, which target fT/fmax cutoff frequencies above 400 GHz, are enabling the development of silicon circuits in the 140-220 GHz range (G-band). To validate these technologies, microwave characterization methods for on-wafer measurements are essential to extract the figures of merit of transistors, passive circuitry and associated parasitics. However, broadband circuits like noise sources (NS), noise receivers and impedance tuners at these frequencies are very incompletely covered by the market offer. Previous research demonstrated that embedding measurement functions directly onto silicon in BiCMOS B55 technology is possible, but this in-situ approach or built-in self-test (BIST) has certain limitations, particularly in terms of the silicon surface allocated to the test circuits alone and also because embedded BIST instrumentation cannot be used for another technology.This thesis broadens the applicability of measurement instrumentation beyond the B55X process and aims to reduce testing costs by transitioning from BIST to smart probes. This new approach focuses on integrating measurement functions into compact systems placed as close as possible to the measurement probes for ex-situ measurements.Building on earlier research achievement as part of a previous thesis, the first-ever packaged NS based on SiGe BiCMOS 55-nm technology was developed and characterized in two distinct configurations. In a first flavor, on-wafer noise measurements yielded an extracted excess noise ratio (ENRav) level of 37 dB in the 140-170 GHz. In an alternative approach, the NS was packaged in a split-block with a WR5.1 flange termination for connection to commercial passive probes, achieving an ENRav level of up to 25 dB in 140-220 GHz corresponding to a 12 dB ENR reduction when compared to the on-wafer measurements.To improve on this work, a key achievement of the present thesis is the development of Ground-Signal-Ground (GSG) probes for on-wafer measurements fabricated using femtosecond laser micromachining with a resolution between 5-10 µm. These probes made from 100 µm thick Schott AF32 glass substrate bonded to a 10 µm thick nickel sheet, demonstrate improved mechanical durability and electrical performance. Nickel was chosen for the tip contacts due to its mechanical hardness and superior electrical properties, which minimize contact resistance and extend probe lifespan. Mechanical testing revealed that while glass-only probes failed at a contact force of 196 mN, the nickel-glass probes withstood forces up to 667 mN. Additionally, these probes achieved low-resistance electrical contacts (0.05 Ω above 6 mN), as verified through four-wire measurements on a single contact point.Furthermore, this research introduces a novel substrate technology that integrates an amplified NS B55X chip onto a glass interposer to reduce dielectric and transition losses. Using femtosecond laser micromachining, the interconnects are precisely structured, allowing the integration of the NS chip on the same substrate used to manufacture the coplanar probing tips, with the advantage of simplifying the signal propagation path. This system achieved a tunable ENRav level of up to 29 dB in the 140-170 GHz range, with constant output impedance matching better than -12 dB across the entire frequency band. This innovation allows for the integration of the GSG probes with the NS to perform on-wafer noise measurements.This research opens new possibilities for cost-effective, scalable millimeter-wave active probes for on-wafer measurements. Their adaptable design makes them suitable for diverse applications, advancing circuit characterization and high-frequency semiconductor testing
19
Silverman, Adam Phillip. "Part I: Detection of RNA in cells with quenched autoligation probes ; probing active site tightness in nucleic acid replication enzymes /." May be available electronically:, 2007. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
Full text
20
Weiß, Stefan [Verfasser], and Burkhard [Akademischer Betreuer] König. "Molecular tools for the NPY Y1 receptor: Dimerization probes, vesicles, catalytically active derivatives and irreversible ligands / Stefan Weiß. Betreuer: Burkhard König." Regensburg : Universitätsbibliothek Regensburg, 2011. http://d-nb.info/1023361566/34.
Full text
21
Oral, Hasan Giray. "Modeling time-resolved interaction force mode AFM imaging." Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/43691.
Full textAbstract:
Intermittent contact mode atomic force microscopy has been widely employed for simultaneous topography imaging and material characterization. The work in the literature includes both qualitative and quantitative methods. Regular AFM cantilevers are generally used in these methods, yet these cantilevers come with certain limitations. These limitations result from the very nature of cantilever probes. They are passive force sensors with insufficient damping. This prevents having active and complete control on tip-sample forces, causing sample damage and inaccurate topography measurement. Ideally, an AFM probe should offer high bandwidth to resolve interaction forces, active control capability for small interaction force and stable operation, and sufficient damping to avoid transient ringing which causes undesired forces on the sample. Force sensing integrated readout and active tip (FIRAT) probe offers these properties. A special imaging mode, time-resolved interaction force (TRIF) mode imaging can be performed using FIRAT probe for simultaneous topography and material property imaging. The accuracy of topography measurement of samples with variations in elastic and adhesive properties is investigated via numerical simulations and experiments. Results indicate that employing FIRAT probe's active tip control (ATC) capability during TRIF mode imaging provides significant level of control over the tip-sample forces. This improves the accuracy of topography measurement during simultaneous material property imaging, compared to conventional methods. Moreover, Active tip control (ATC) preserves constant contact time during force control for stable contact while preventing loss of material property information such as elasticity and adhesive forces.
22
Bontempi, Alexia. "Microscopie thermique par sonde thermoélectrique." Thesis, Besançon, 2015. http://www.theses.fr/2015BESA2025/document.
Full textAbstract:
Ce mémoire de thèse s’inscrit dans le développement d’un microscope thermique à sonde locale.Ce système d’imagerie présente deux modes de fonctionnement permettant de déterminer soit unetempérature de surface soit des propriétés thermophysiques de matériaux. Un micro-thermocouplebifilaire a été utilisé comme capteur thermique. Il est peu invasif et permet d’accéder à destempératures de surface sur une large gamme de température. De plus, le microscope offrel’avantage d’être moins sensible à la nature optique des échantillons que les méthodes en champlointain. Dans le but de maitriser le contact entre la sonde et la surface, un résonateur à quartz(diapason) a été utilisé comme capteur de force. Un système d’excitation original basé sur l’effetphoto-thermo-élastique a été mis au point. Le microscope fonctionne donc comme un SThM puisqu’ilpermet d’extraire simultanément des images topographiques et thermiques (régime périodique 2 et3 oméga). En revanche, les résultats obtenus ont permis de mettre en évidence les avantages dumicro-thermocouple en termes de résolutions spatiales topographiques vis-à-vis des techniques àsondes résistives fonctionnant en mode 3 omégaThis PhD thesis deals with the development of a thermalmicroscope using a local probe. This imagingsystem presents two functioning modes that allow determining either surface temperature or thermalproperties of materials. A micro-wire thermocouple is used as a thermal sensor. It is less invasiveand allows measuring the surface temperature with a large temperature range. Furthermore, themicroscope offers an advantage to be less sensitive to the optical nature of a sample surface thanoptical methods. To control the contact between the probe and the surface, a quartz tuning fork hasbeen used as a force sensor. An original excitation system has been developed based on the photothermaleffect. The microscope works also as a SThM since it permits to extract simultaneouslytopographical and thermal pictures (2 and 3 omega periodical modes). Results underlining themicro-thermocouple advantages, in terms of topographical compared to resistive probe techniquesfunctioning with the 3 omega method, have been obtained
23
Weiss, Kevin L. "Structural probes of retinoid action /." The Ohio State University, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=osu1486394475977697.
Full text
24
Urquhart, Colin W. "The active stereo probe : the design and implementation of an active videometrics system." Thesis, University of Glasgow, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312498.
Full text
25
Gilet, Nicolas. "Modélisation et calibration des sondes à impédance mutuelle : Application à la sonde MIP à bord de Rosetta et préparation de BepiColombo et JUICE." Thesis, Orléans, 2019. http://www.theses.fr/2019ORLE3020.
Full textAbstract:
Les sondes à impédance mutuelle sont des instruments permettant de déterminer la densité et la température des électrons dans les plasmas spatiaux. Basées sur des mesures actives in-situ, elles ont été embarquées sur des satellites dès le début des années 1960 pour analyser les plasmas terrestres. Elles sont depuis quelques années confrontées à de nouveaux types de plasmas tels que le plasma cométaire de 67P/Churuymov-Gerasimenko (mission Rosetta, 2004-2016) et le seront de nouveaux dans quelques années dans l’environnement plasma de Mercure (mission BepiColombo, lancée en 2018) et de Jupiter et ses lunes (mission JUICE, lancement prévu en 2022).Le but de cette thèse est de développer de nouvelles méthodes de modélisation de la réponse instrumentale de ces sondes afin de tenir compte des nouvelles conditions plasmas rencontrées par ces sondes à impédance mutuelle pour les missions spatiales d’exploration planétaire. Grâce à ces nouvelles modélisations, il a été possible d’accéder à de nouvelles observables telles qu’un mélange de différentes populations électroniques dans l’environnement de la comète 67P sur les données de la sonde RPC-MIP. Cette modélisation a également permis de comprendre et d’identifier les effets du satellite Rosetta sur les mesures in-situ. Enfin, nous avons modélisé les réponses instrumentales dans les conditions plasmas attendues par la sonde PWI/AM2P (resp. RPWI/MIME) dans l’environnement de Mercure (resp. dans l’environnement jovien). Ces travaux permettent d’apporter une aide aux choix des modes d’opération des sondes ainsi qu’au futur traitement des données permettant de déterminer les paramètres plasmas à partir des mesures d’impédance mutuelleMutual impedance probes operates in space plasma to caracterize the electron density and temperature. Based on active in-situ measurements, they were on-boarded spacecraft in the early 1960s to analyze the terrestrial plasmas. In recent years, they have been used in new plasmas such as the cometary plasma of 67P/Churuymov-Gerasimenko (Rosetta mission, 2004-2016) and will operate in the plasma environment of Mercury (BepiColombo mission, launched in 2018) and Jupiter and its moons (JUICE mission, launch planned for 2022).The main goal of this thesis is to develop new methods to model the instrumental response of these probes in order to take into account the plasma conditions encountered by the exploratory space missions. Thanks to this modeling, it was possible to characterize a mix of several electron populations in the cometary environment of 67P from the RPC-MIP dataset. This modeling also enables to understand and identify the effects of the Rosetta spacecraft on the in-situ measurements. Finally, we modelled the instrumental response in the plasma conditions expected for the PWI/AM2P (resp. RPWI/MIME) probe in the Hermean environment (resp. in the Jovian system). The modeling enables to caracterize the plasma parameters on mutual impedance measurements by choosing the most efficient operational mode and helping the future data processing
26
Dahlin, Anton. "Enabling Pro-active Problem Management by Predictive Modelling : Data mining and statistical analysis of past problems to enable pro-active actions for Internet Protocol Television." Thesis, KTH, Skolan för informations- och kommunikationsteknik (ICT), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-210636.
Full textAbstract:
Service providers strive to guarantee a certain level of quality of their services, to stay relevant and to keep their customers satisfied and to avoid customer churn. IPTV is such a service. To be able to guarantee quality of service and uptime a good problem management system is vital. Problem management system, are a system of handling occurrences and solutions of all problems and errors. Its primary goal is to detect, prevent and solve errors and incidents, but also prevent reoccurring errors and minimizing the time line of existing problems by finding its root cause. On first contact of a problem there is human operators classifying the problem. Problems with problem management is that it is reactive and problems keep happening. To be able to become pro-active, problems need to be predicted before they occur. This thesis evaluates past problems to enable pro-active actions, by statistics and actionable data mining, using performance data from IPTV service and set top boxes, not utilized today by the company this thesis is carried out for. The result shows that pro-active actions are enabled by adding supervision of the performance data and a packet error ratio. The result also shows that some large problems gets classified too late. By utilizing machine learning and predictive modelling: Logistic regression and Artificial neural network, future disturbance incidents can be predicted. Using disturbance data gave a model accuracy of 80% and 80% respectively with a model Matthew correlation coefficient of 0.50 and 0.56 respectively. Given information of affected active service consumers, if provided, customer impact could easier be assessed. The larger part of this project went to the business understanding, data understanding, data preparation and analysis. By utilizing the unutilized performance data, the problem management system can become more proactive, with the addition of supervision of the IPTV performance data and predictive modelling.Tjänsteleverantörer strävar att kunna garantera en viss grad av kvalité på de tjänster de erbjuder, för att fortsätta vara relevant, hålla sina kunder nöjda och undvika bortfall av kunder. IPTV är en sådan tjänst. För att kunna garantera en hög tjänstekvalité och hög drifttid, är ett bra problemhanteringssystem viktigt. Problemhanteringssystem är ett system som hanterar förekomsten av och lösningar till alla problem och fel. Dess primära mål är att upptäcka, motverka och lösa incidenter och fel. Även att motverka fortsatt upprepande fel samt att minimera tidslinjen för aktiva fel genom att hitta dess grundorsaken. Vid första kontakt av ett problem så är det mänskliga operatörer som klassificerar problemet. Ett problem med problemhanteringssystem är att de är reaktiva och problem fortsätter att uppkomma. För att kunna bli proaktiv, måste problem kunna predikteras innan de uppkommer. Denna uppsats utvärderar och analyserar gamla problem och incidenter för att möjliggöra proaktivitet, genom statistik och handlingsbar data mining, genom användandet av oanvända prestandadata från IPTV tjänst och digitalbox. Resultat visar att proaktivt agerande möjliggörs genom att lägga till bevakning av prestandadata och en paketfels kvot. Resultat visar även att stora problem blir klassificerad för sent. Genom användandet av maskininlärning och prediktiva modeller: logistisk regression och artificiellt neuralt nätverk, kan kommande incidenter predikteras. Användning av störningsdata gav en modellsäkerhet på 80% och 80% med en Matthew korrelations koefficient på 0.50 och 0.56 respektive. Information om antal aktiva påverkade kunder, om implementerat, hjälper till att bedöma kundpåverkan. Den större delen av detta projekt gick åt till företag förståelse, data förståelse, data förberedning och analys. Men genom användandet av prestandadata, kan problemhanteringssystemet bli proaktiv med tillägget av bevakning av IPTV tjänst och digitalbox data och prediktiv modellering.
27
Hutchinson, William Edward. "Molecular sensing using immobilized IR-active carbonylmetal probe groups." Thesis, Nottingham Trent University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369254.
Full text
28
Regal, Kelly Anne. "Caffeine as an active site probe of cytochrome P4501A2 /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/8168.
Full text
29
Baek, Kwang-Hyun. "Non-linear optimisation problems in active control." Thesis, University of Southampton, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243131.
Full text
30
Hurth, Cédric M. "Scanning probe microscopy studies of active enzymes at solid surfaces." Bordeaux 1, 2005. http://www.theses.fr/2005BOR13106.
Full textAbstract:
Plusieurs enzymes sont étudiées différentes techniques de microscopies à champ proche afin d'extraire des propriétés mécaniques, électrochimiques et électriques locales. Tout d'abord, la 3-phosphoglycérate kinase de levure (PGK) est étudiée en Microscopie à Force Atomique (MFA) de à la fois ex situ et in situ en mode dynamique par comparaison au mode statique (Contact). Conjointement, l'activité enzymatique de l'enzyme immobilisé est mesurée par spectrophotométrie UV visible et comparée aux constantes connues en solution. Ensuite, la glucose oxydase est étudié par Microscopie Electrochimique à Balayage (SECM) de façon à extraire les constantes catalytiques hétérogènes pour divers supports solides et à caractériser l'éventuelle dépendance de l'activité enzymatique avec un champ électrique continu externe. Une étude critique de la stratégie choisie est présentée avant de se concentrer sur la décomposition catalytique du peroxyde d'hydrogène par la catalase et des nanoparticules de platine liées à une surface solide isolante. Cette étude permet d'introduire une stratégie alternative plus appropriée à l'étude de la dépendance avec le champ électrique continu externe. Enfin, une nouvelle technique, la Microscopie Electrochimique de Potentiel à Balayage (SECPM), est étudiée d'un point de vue essentiellement d'instrumentation car elle se propose prochainement de cartographier le potentiel de surface d'un enzyme alors qu'il réalise son acte catalytique. Plusieurs modifications visant à réduire l'influence perturbatrice des procédés faradiques dus à la présence d'oxygène dissous et de protons en solutions aqueuses non tamponnées sont introduites.
31
Pasolli, Edoardo. "Active learning methods for classification and regression problems." Doctoral thesis, Università degli studi di Trento, 2011. https://hdl.handle.net/11572/368080.
Full textAbstract:
In the pattern recognition community, one of the most critical problems in the design of supervised classification and regression systems is given by the quality and the quantity of the exploited training samples (ground-truth). This problem is particularly important in such applications in which the process of training sample collection is an expensive and time consuming task subject to different sources of errors. Active learning represents an interesting approach proposed in the literature to address the problem of ground-truth collection, in which training samples are selected in an iterative way in order to minimize the number of involved samples and the intervention of human users.
In this thesis, new methodologies of active learning for classification and regression problems are proposed and applied in three main application fields, which are the remote sensing, biomedical, and chemometrics fields. In particular, the proposed methodological contributions include: i) three strategies for the support vector machine (SVM) classification of electrocardiographic signals; ii) a strategy for SVM classification in the context of remote sensing images; iii) combination of spectral and spatial information in the context of active learning for remote sensing image classification; iv) exploitation of active learning to solve the problem of covariate shift, which may occur when a classifier trained on a portion of the image is applied to the rest of the image; moreover, several strategies for regression problems are proposed to estimate v) biophysical parameters from remote sensing data and vi) chemical concentrations from spectroscopic data; vii) a framework for assisting a human user in the design of a ground-truth for classifying a given optical remote sensing image.
Experiments conducted on simulated and real data sets are reported and discussed. They all suggest that, despite their complexity, ground-truth collection problems can be tackled satisfactory by the proposed approaches.
32
Pasolli, Edoardo. "Active learning methods for classification and regression problems." Doctoral thesis, University of Trento, 2011. http://eprints-phd.biblio.unitn.it/638/1/PhD-Thesis-Pasolli.pdf.
Full textAbstract:
In the pattern recognition community, one of the most critical problems in the design of supervised classification and regression systems is given by the quality and the quantity of the exploited training samples (ground-truth). This problem is particularly important in such applications in which the process of training sample collection is an expensive and time consuming task subject to different sources of errors. Active learning represents an interesting approach proposed in the literature to address the problem of ground-truth collection, in which training samples are selected in an iterative way in order to minimize the number of involved samples and the intervention of human users.
In this thesis, new methodologies of active learning for classification and regression problems are proposed and applied in three main application fields, which are the remote sensing, biomedical, and chemometrics fields. In particular, the proposed methodological contributions include: i) three strategies for the support vector machine (SVM) classification of electrocardiographic signals; ii) a strategy for SVM classification in the context of remote sensing images; iii) combination of spectral and spatial information in the context of active learning for remote sensing image classification; iv) exploitation of active learning to solve the problem of covariate shift, which may occur when a classifier trained on a portion of the image is applied to the rest of the image; moreover, several strategies for regression problems are proposed to estimate v) biophysical parameters from remote sensing data and vi) chemical concentrations from spectroscopic data; vii) a framework for assisting a human user in the design of a ground-truth for classifying a given optical remote sensing image.
Experiments conducted on simulated and real data sets are reported and discussed. They all suggest that, despite their complexity, ground-truth collection problems can be tackled satisfactory by the proposed approaches.
33
Yaqoob, Tahir. "X-ray spectral variability as a probe of Active Galactic Nuclei." Thesis, University of Leicester, 1990. http://hdl.handle.net/2381/35836.
Full textAbstract:
This thesis is concerned with how studies of variability in the X-ray spectrum of Active Galactic Nuclei (AGN) can place constraints on physical models of the X- ray emission and absorption mechanisms in such objects. An underlying theme of the thesis is to place emphasis on modelling individual objects as well as a class of objects and to this end the Seyfert I galaxy, NGC 4151, has been targeted for an individual case study. NGC 4151 is ideally suited for the present purpose as it has been extensively studied in all wavebands, from radio to X-ray energies and has long been known to exhibit X-ray spectral variability. We first review the diagnostics of AGN which are of contemporary importance, mainly due to studies of the optical/ UV emission-line spectrum, and outline how the study of X-ray spectral variability may be used as an additional diagnostic tool. We then present the results of an extensive (~ 5.5 year) monitoring campaign of NGC 4151 with EXOSAT and Ginga. The medium energy X-ray flux exhibited large amplitude variability accompanied by significant spectral variations. We show that these spectral changes can be attributed to both changes in the configuration of the X-ray absorbing material in the nucleus (independent of the continuum level) and in the spectral index of X-ray power law which is correlated with the 2-10 keV flux. We then investigate some theoretical models of spectral index variability and of complex and variable absorption. The implications of these models for AGN in general and NGC 4151 in particular are discussed. We also present X-ray observations of two other AGN, namely ESO 103-G35 and QSO 1821+643, both of which exhibit significant X-ray spectral variability. The results are discussed in terms of contemporary models.
34
Barnabé-Lortie, Vincent. "Active Learning for One-class Classification." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/33001.
Full textAbstract:
Active learning is a common solution for reducing labeling costs and maximizing the impact of human labeling efforts in binary and multi-class classification settings. However, when we are faced with extreme levels of class imbalance, a situation in which it is not safe to assume that we have a representative sample of the minority class, it has been shown effective to replace the binary classifiers with a one-class classifiers. In such a setting, traditional active learning methods, and many previously proposed in the literature for one-class classifiers, prove to be inappropriate, as they rely on assumptions about the data that no longer stand.
In this thesis, we propose a novel approach to active learning designed for one-class classification. The proposed method does not rely on many of the inappropriate assumptions of its predecessors and leads to more robust classification performance. The gist of this method consists of labeling, in priority, the instances considered to fit the learned class the least by previous iterations of a one-class classification model.
Throughout the thesis, we provide evidence for the merits of our method, then deepen our understanding of these merits by exploring the properties of the method that allow it to outperform the alternatives.
35
Kanchana, Manohar Arthi. "Participatory action research for emotionally meaningful stories." Thesis, University of Dundee, 2017. https://discovery.dundee.ac.uk/en/studentTheses/b87e9215-e617-4144-9508-c64ee5950be4.
Full textAbstract:
In this thesis, I developed an empirically and theoretically grounded understanding of participatory action research (PAR). My aim was to develop and explore PAR methods within three culturally different fishing communities located in India, Portugal and the UK in order to generate emotionally meaningful stories. The work was conducted as part of the practice-led TOTeM research project and aspires to be associated with such works that have been able to make a methodological contribution by introducing theoretical insights, innovative methods and analytical concepts. In this study, the key finding is revealing the importance of the preliminary activities that helped design the innovative methods. I assess how my PAR methods, such as story interviews, digital storytelling workshops and story kits, helped me to gather participants’ personal experiences within the three chosen communities. Photographs and ‘objects’ provided a medium through which to identify stories that were emotionally meaningful to the participants. These stories gathered from the three chosen communities were analysed through a story narrative analysis method. Each method evoked strong, emotionally meaningful responses from the participants with regard to human relationships and demonstrated the vital role of objects in identifying stories that illustrate the participants’ intimate relationships. The collective findings from the three communities established that the methods utilised provided a new way of synthesising storytelling with digital technologies. The findings reinforce the role played by the participants as co-creators in collaboratively designing the methods, enabling me to craft a better way to gather stories. Upon critical reflection of the methods, supporting evidence was found that storytelling serves as an invaluable technique in providing participants with opportunities to explore their cultural identity through uniquely self-reflecting narratives and shared moments. I present the three stages of the participatory methods as my story culture framework and the findings and challenges as my original contribution to knowledge. I propose that this transferable framework will support designers as they engage with various settings to elicit information from user and stakeholder participants, develop their own experiential and critical perspectives and utilise their intuitive and expressive expertise to establish, manage and sustain productive human-centred design relationships.
36
Ovarienė, Dovilė. "Probiotiko probio - active įtaka melžiamų karvių produktyvumui ir sveikatingumui." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2014. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2014~D_20140519_092447-56528.
Full textAbstract:
Darbo tikslas: ištirti probiotikų įtaką melžiamų karvių produktyvumui, produkcijos rodikliams ir sveikatingumui.
Darbo uždaviniai: 1. Įvertinti probiotiko Probio - active įtaką melžiamų karvių pieno primilžiui ir pieno rodikliams. 2. Įvertinti probiotiko įtaką melžiamų karvių kraujo morfologiniams rodikliams. 3. Įvertinti probiotiko įtaką melžiamų karvių didžiojo prieskrandžio fermentaciniams procesams.
Tyrimo metodika: tyrimas buvo atliekamas kooperatinėje bendrovėje „Blauzdžių agroservisas“, 2013 metų birželio – spalio mėnesiais.
Bandymo metu buvo suformuotos dvi grupės melžiamų karvių: kontrolinė ir bandomoji, po 115 Lietuvos juodmargių veislės melžiamų 2-5 laktacijos karvių kiekvienoje. Kontrolinėje ir bandomojoje grupėse karvės buvo paskirstytos vienodai, atsižvelgiant į jų laktacijų skaičių ir veršiavimosi laiką. Bandomosios grupės karvės su įprastiniu racionu papildomai gavo probiotiko. Į kiekvienos bandomosios grupės karvių kombinuotuosius pašarus, kiekvieną šėrimo dieną individualiai, buvo įmaišoma po 150 ml probiotiko.
Bandymas vyko nuo 60-os iki 120-os karvių laktacijos dienos ir truko 60 dienų. Pirmas 30 dienų bandymas vyko tvartiniu laikotarpiu, o paskutines 30 dienų – ganykliniu laikotarpiu .
Bandymo metu buvo naudotas probiotikas Probio - active, įmaišytas į racioną normuojant po 150 ml kiekvienai karvei, normą padalinant į dvi dalis ir sušeriant paros laike per du šėrimus.
Tyrimo metu mėginiai pieno tyrimams buvo imami bandymo pradžioje, praėjus 60 d., 90 ir... [toliau žr. visą tekstą]Aim: to research the effects of probiotics on dairy cows’ productivity, productions values and the overall health. Objectives: 1. To evaluate the effects Probio – active probiotics toward dairy cows’ yield and milk index. 2. To evaluate the effects of probiotics on dairy cows morphological blood indexes. 3. To evaluate the effects of probiotics to the rumens fermentation processes on dairy cows. Methodology of the research: the research was carried out at the cooperative company “Blauzdžių Agroservisas” 2013 June - October. During the research two similar groups of dairy cows were created: the control group and experimental group. The groups were made out of 115 Lithuanian Black and White breed dairy cows in their 2-5 lactation stages each. Cows were considered and maintained under the same conditions. For the experimental group cows with normal diet each day in addition received 150 ml of a probiotic. The study samples of milk were taken for research at the beginning of the test after 60 days, 90 and 120 days, from the start. Haematological tests of dairy cows blood samples were taken at the beginning and the end. The rumen contents - at the beginning and after a two-month test. Results: during the research it was determined that the cows which received probiotics yielded 4.4 percent (p>0.05) more milk opposed to the ones that did not receive probiotics. It was also detriment that the use of probiotics have an effect on the quality indexes (protein, fat), and have... [to full text]
37
Mahault, Benoît. "Outstanding problems in the statistical physics of active matter." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS250/document.
Full textAbstract:
La matière active, désignant les systèmes hors d’équilibre composés de particules étant capable d’utiliser l’énergie présente dans leur environnement afin de se déplacer de façon systématique, a suscité beaucoup d’attention auprès des communautés de mécanique statistique et matière molle ces dernières décennies. Les systèmes actifs couvrent en effet un large panel d’exemples allant de la biologie aux granulaires. Cette thèse se concentre sur l’étude de modèles minimaux de matière active sèche (ceux pour lesquels le fluide dans lequel les particles sont immergées est négligé), tel que le modèle de Vicsek qui considère des particules ponctuelles se déplaçant à vitesse constante tout en alignant leur direction de mouvement avec celles de leurs voisins localement en présence de bruit, et définit une classe d’universalité hors équilibre pour la transition vers le mouvement collectif. Quatre problèmes en suspens ont été abordés : La définition d’une classe d’universalité en matière active sèche qui décrit des systèmes de particles présentant un alignement polaire et un mouvement apolaire. Cette nouvelle classe exhibe une transition continue vers un quasi-ordre polaire doté d’exposants variant continument, et donc analogue au modèle XY à l’équilibre, mais n’appartenant pas à la classe d’universalité Kosterlitz-Thouless. Ensuite, l’étude de la validité des théories cinétiques décrivant les modèles de type Vicsek, qui sont confrontées aux résultats obtenus aux niveaux microscopique et hydrodynamique. Puis une évaluation quantitative de la théorie de Toner et Tu, permettant de mesurer les exposants caractérisant les fluctuations dans la phase ordonnée du modèle de Vicsek, à partir de simulations numériques à grande échelle du modèle microscopique. Enfin, la création d’un formalisme pour la dérivation d’équations hydrodynamiques à partir de modèles de matière active sèche à trois dimensions, ainsi que leur étude au niveau linéaireActive matter, i.e. nonequilibrium systems composed of many particles capable of exploiting the energy present in their environment in order to produce systematic motion, has attracted much attention from the statistical mechanics and soft matter communities in the past decades. Active systems indeed cover a large variety of examples that range from biological to granular. This Ph.D. focusses on the study of minimal models of dry active matter (when the fluid surrounding particles is neglected), such as the Vicsek model: point-like particles moving at constant speed and aligning their velocities with those of their neighbors locally in presence of noise, that defines a nonequilibrium universalilty class for the transition to collective motion. Four current issues have been addressed: The definition of a new universality class of dry active matter with polar alignment and apolar motion, showing a continuous transition to quasilong-range polar order with continuously varying exponents, analogous to the equilibrium XY model, but that does not belong to the Kosterlitz-Thouless universality class. Then, the study of the faithfulness of kinetic theories for simple Vicsek-style models and their comparison with results obtained at the microscopic and hydrodynamic levels. Follows a quantitative assessment of Toner and Tu theory, which has allowed to compute the exponents characterizing fluctuations in the flocking phase of the Vicsek model, from large scale numerical simulations of the microscopic dynamics. Finally, the establishment of a formalism allowing for the derivation of hydrodynamic field theories for dry active matter models in three dimensions, and their study at the linear level
38
Thomas, Kimberly M. "Generating alternative solutions to social problems : an evaluation of active and inactive approaches." Virtual Press, 1993. http://liblink.bsu.edu/uhtbin/catkey/864914.
Full textAbstract:
Two experiments were designed to compare methods of generation used in solving social problems. First, the experimenters explored the effectiveness of a new approach based on hierarchical organization. One hour of training was sufficient for subjects to learn the technique.Subjects reported that they found the hierarchical technique to be very valuable and easy to use.The purpose of the second experiment was to compare three methods of generation, two active methods and an inactive approach. Clearly, active participants generated more solutions to a social problem than subjects in the inactive condition. This result points to the importance of direct problem solving training.The performance of participants in the active hierarchical and brainstorming conditions was compared. Although the two approaches were equally effective in facilitating the production of numerous, quality solutions, the experimenters found the hierarchical technique to be a superior method of generation for practical problems.Department of Psychological Science
39
Litven, Joshua Alexander. "A parallel active-set method for solving frictional contact problems." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43934.
Full textAbstract:
Simulating frictional contact is a challenging computational task and there exist a variety of techniques to do so. One such technique, the staggered projections algorithm, requires the solution of two convex quadratic program (QP) subproblems at each iteration. We introduce a method, SCHURPA, which employs a primal-dual active-set strategy to efficiently solve these QPs based on a Schur-complement method. A single factorization of the initial saddle point system and a smaller dense Schur-complement is maintained to solve subsequent saddle point systems. Exploiting the parallelizability and warm-starting capabilities of the active-set method as well as the problem structure of the QPs yields a novel approach to the problem of frictional contact. Numerical results of a parallel GPU implementation using NVIDIA’s CUDA applied to a physical simulator of highly deformable bodies are presented.
40
Beck, Terence A. "The influence of civics problem-solving steps and audience roles on substantive student engagement in fourth grade /." Thesis, Connect to this title online; UW restricted, 2000. http://hdl.handle.net/1773/7595.
Full text
41
Bittle, Steven Douglas. "An active piezoelectric probe for precision measurement on a coordinate measuring machine (CMM)." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/18186.
Full text
42
Chrétien, Anne-Sophie. "Contrat et action en justice." Nantes, 2000. http://www.theses.fr/2000NANT4013.
Full textAbstract:
Alors que le contrat est concours de volontes, l'action en justice, qui renvoie aux notions de litige, de proces, evoque un conflit de volontes. Comment peut-il y avoir accord entre des concepts aussi opposes ? pourtant, le paradoxe denonce n'est, en realite que purement apparent. L'abandon du principe de l'autonomie de la volonte, comme fondement de la force obligatoire du contrat, conjuguee a l'evolution contemporaine du proces civil rend possible l'ouverture de la sphere contractuelle au juge. Guide par le role principal qui lui est reserve dans le proces civil, le juge est devenu, sous l'impulsion des textes de procedure civile, le promoteur de l'existence du contrat et l'architecte de son contenu. D'une relation binaire, decrite par l'article 1101 du code civil, nous passons, au moment du proces, a une relation triangulaire composee des parties et du juge. Desormais, si le contrat n'est plus totalement la chose des parties, le proces n'est pas davantage l'uvre exclusive du juge. La nouvelle philosophie du proces, associee a un essor du concept contractuel, favorise la penetration du contrat dans le domaine du proces. Il a toujours existe des conventions relatives a l'action en justice, telles les clauses attributives de competence, le compromis ou la transaction, mais la nouveaute tient a la progression de la liberte contractuelle sur le terrain des conventions amenageant le traitement juridictionnel du litige et, plus singulierement encore, a la proliferation du contrat dans le domaine de la solution des litiges. Mais, a son tour, ce mouvement de contractualisation du proces appelle une intervention du juge, significative du phenomene de compenetration et de complementarite qui preside les relations entre le contrat et l'action en justice.
43
Wilmot, Timothy Allen Jr. "Intelligent Controls for a Semi-Active Hydraulic Prosthetic Knee." Cleveland State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=csu1315531357.
Full text
44
Gupta, Vaibhav. "A Characterization of Wireless Network Interface Card Active Scanning Algorithms." Digital Archive @ GSU, 2006. http://digitalarchive.gsu.edu/cs_theses/28.
Full textAbstract:
In this thesis, we characterize the proprietary active scanning algorithm of several wireless network interface cards. Our experiments are the first of its kind to observe the complete scanning process as the wireless network interface cards probe all the channels in the 2.4GHz spectrum. We discuss the: 1) correlation of channel popularity during active scanning and access point channel deployment popularity; 2) number of probe request frames statistics on each channel; 3) channel probe order; and 4) dwell time. The knowledge gained from characterizing wireless network interface cards is important for the following reasons: 1) it helps one understand how active scanning is implemented in different hardware and software; 2) it can be useful in identifying a wireless rogue host; 3) it can help implement Active Scanning in network simulators; and 4) it can radically influence research in the familiar fields like link-layer handovers and effective deployment of access points.
45
Chen, Hongshi. "Contribution to Active Probe for SNOM and Nanoscale Light-matter Interaction based on Photopolymerization." Electronic Thesis or Diss., Troyes, 2022. http://www.theses.fr/2022TROY0007.
Full textAbstract:
La microscopie optique en champ proche à balayage (SNOM) est une technologie d'imagerie optique à haute résolution. L'information associée aux hautes fréquences spatiales du champ proche est associée à une haute résolution spatiale, permettant de dépasser la limite de diffraction. Développer une sonde optique locale efficace reste un sujet clé d'actualité qui est abordé depuis longtemps. La thèse porte sur le développement d'une sonde en champ proche active basée sur une pointe polymère intégrée à l'extrémité d'une fibre optique. Nous avons polymérisé une pointe en polymère sur la surface de l'extrémité de la fibre. Pour le balayage, les forces locales de cisaillement détectées à l’aide d’un micro diapason sur lequel est collée la sonde sont utilisées pour contrôler la distance sonde-échantillon. Après fonctionnalisation de surface de la sonde polymère, quelques nano-émetteurs ont été attachés sur l'extrémité de la sonde, pour obtenir une sonde active. Les nano-émetteurs peuvent servir de source lumineuse locale pour la sonde active. La stratégie d’intégration de nano-emetteurs développée a été utilisée sur des nanocubes d'or sur substrat, pour concevoir des nano-émetteurs de plasmons hybrides sensibles à la polarisation. Nous avons également étendu ces nano-émetteurs hybrides au régime de photon unique. Enfin, la sonde active a été testée sur deux types d'échantillons : des nanofils d'argent et des nanocubes d'or. En utilisant notre nouvelle sonde active, nous avons collecté des informations de champ proche pour ces nanostructures et dépassé la limite de diffractionScanning Near-field Optical Microscope (SNOM) is a technology for high resolution optical imaging. The high spatial frequency information from the near-field is associated to high spatial resolution, allowing one to break the diffraction limit. The used local probe is still a key topical issue that has been addressed for long. The thesis deals with the development of an active near-field probe based on a polymer tip integrated at the extremity of an optical fiber. We polymerized polymer tip on the surface of the fiber end as a scanning optical probe. Shear-force method with micro tuning fork is used for controlling the probe-sample distance. After surface functionalization of the polymer probe, a few nano-emitters have been attached on the probe extremity, to obtain an active probe. Upon excitation, the nano-emitters can act as local light source for the active probe. Besides, while the development of such active hybrid probes turned out to be challenging, the developed strategy of attachment has been used on gold nanocubes on substrate, to create polarization-sensitive hybrid plasmon nano-emitters. We also extended this hybrid nano-emitters to single photon regime. Finally, the active probe was tested on two kinds of samples: silver nanowires and gold nanocubes. By using our new active probe, we obtained near-field information for those nanostructures and broke the diffraction limit
46
Wilkins, Daniel Richard. "Understanding X-ray reflection as a probe of accreting black holes." Thesis, University of Cambridge, 2013. https://www.repository.cam.ac.uk/handle/1810/244941.
Full textAbstract:
The reflection of the X-rays emitted from a corona of energetic particles surrounding an accreting black hole from the accretion disc is investigated in the context of probing the structure of the central regions as well as the physical processes that power some of the brightest objects seen in the Universe. A method is devised to measure the emissivity profile of the accretion disc, that is the reflected flux as a function of radius in the disc. This method exploits the variation in the Doppler and gravitational redshift of emission from different radii in the disc to fit the observed reflection spectrum as the sum of contributions from successive radii and is applied to X-ray spectra of the narrow line Seyfert 1 galaxies 1H 0707-495, IRAS 13224-3809 and MCG-6-30-15 as well as the Galactic X-ray binary, Cygnus X-1. This illumination pattern of the accretion disc is a sensitive probe of the geometry of the corona that is illuminating the disc. A formalism is developed in which systematic ray tracing simulations can be run between X-ray emitting coronae and the accretion disc for a range of source geometries and other physical parameters, allowing observable data products to be simulated that can be directly compared to data from astrophysical black holes, in order to determine how these parameters affect the observed data, allowing them to be constrained observationally. The measured emissivity profiles are found to be in agreement with those expected theoretically and it is also discovered that the measured emissivity profile can be used to determine the radial extent of the X-ray emitting corona above the accretion disc. The X-ray emitting coronae are located and their radial extents constrained in 1H 0707-495, IRAS 13224-3809 and MCG-6-30-15, while the insight gained into accretion disc emissivity profiles from ray tracing simulations allows the low flux state that 1H 0707-495 was seen to drop in to in January 2011 to be explained in terms of a collapse of the X-ray emitting corona to a confined region around the central black hole. The rapid variability of the X-ray emission from accreting black holes is exploited in the use of reverberation time lags, where variability in the continuum is seen to lead that in its reflection from the accretion disc, to measure the distances between the X-ray emitting corona and the reflector. Ray tracing calculations are developed to simulate lag spectra that can be measured in X-ray observations to provide a means of constraining the extent and geometry of the corona, complimentary to the use of the emissivity profiles. Combining these methods, the X-ray emitting coronae are constrained to extend radially outward a few tens of gravitational radii over the accretion disc, while extending vertically a few gravitational radii above the plane of the disc. Furthermore, it is demonstrated how measured lag spectra can be used to understand the propagation of luminosity fluctuations through the extent of the corona and techniques are developed for analysing energy-resolved variability analysis that will be possible with future generations of X-ray telescopes. Finally, these methods, along with theoretical insight gained form ray tracing simulations, are applied to X-ray spectra extracted from 1H 0707-495 during periods of low and high flux during the observations. Evidence is found for the expansion of the corona along with a drop in the average energy density as the X-ray luminosity increases followed by its contraction as the luminosity decreases on timescales of hours.
47
Mahon, Gary Scott. "The performance of highly active problem solving stratgies in novel task environments." Diss., The University of Arizona, 2000. http://hdl.handle.net/10150/289217.
Full textAbstract:
A series of simulation experiments evaluated the performance of seven different rule-based problem-solving strategies. Each of the strategies was based on a small set of decision rules that used performance feedback from prior actions to determine future behavior. Several environmental task factors were studied including feedback error, complexity, and system dynamics. The results showed that different strategies perform well in some environments but not in others. No one strategy performed well across the range of environments studied here. The implications for human decision-makers are that in order to be successful across a variety of tasks, a person must possess a broad repertoire of problem solving strategies and know when and how to apply them. In addition, two laboratory experiments were conducted with human subjects using the same task factors as in the simulation experiments. The findings lend support to a new theory on problem solving in novel task environments. In stable, positive, and non-declining environments, human decision-makers employed a two-stage approach to maximizing their payoff. Behavior in the first stage was characterized by bold actions that were used to explore the environment and gain a basic understanding of the payoff distribution. Approximately one third of the way through the task, subjects changed their problem solving strategy to a more systematic, small step approach similar to the way many of the rule-based simulated subjects behaved. Another interesting result was the inability of subjects to improve their performance in their second run. Relatively minor changes to the task from one run to the next were enough to block the ability to transfer knowledge from the first run to the second. Additionally, 12% of the runs in the laboratory experiment performed at a level that was less than or equal to what could have been achieved simply by choosing settings at random. These results suggest that subjects performing at this level could have saved a considerable amount of cognitive effort by taking random actions. Additional research is needed to evaluate new task factors, alternative problem-solving strategies, and gain a better understanding of the two-stage approach.
48
Zhao, Sihong. "Dynamic Characterization and Active Modification of Viscoelastic Materials." Miami University Honors Theses / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=muhonors1303742497.
Full text
49
Escolle, Clément. "Optique active spatiale pour l'observation à haute résolution." Thesis, Aix-Marseille, 2015. http://www.theses.fr/2015AIXM4767/document.
Full textAbstract:
Pour relever les défis de l'observation de la Terre et de l'astronomie, les futurs observatoires spatiaux vont requérir des télescopes de plusieurs mètres de diamètre. Les différentes contraintes liées à l'environnement spatial vont induire des déformations et des désalignements des miroirs du télescope dégradant ainsi la qualité optique des observations. L'intégration de l'optique active, utilisée depuis la fin des années 80 pour l'alignement et le maintien de la qualité optique des télescopes au sol, devient donc nécessaire. Un tel système est constitué de trois éléments : un dispositif de mesure, une fonction de correction et une boucle de contrôle qui fait le lien entre les deux éléments précédents.Les travaux de recherche présentés dans ce mémoire de doctorat s'attachent, d'une part, au développement d'un estimateur des perturbations minimisant le front d'onde résiduel dans le champ du télescope. L'analyse de cet estimateur et plus généralement des performances ultimes d'un système d'optique active spatial nous a permis de mettre en évidence l'impact des hautes fréquences spatiales sur la qualité optique. La présence de telles hautes fréquences dues à l'empreinte des supports du miroir primaire nous a poussés, d'autre part, à évaluer les possibilités de leur réduction dans le cas d'un miroir de grande dimension. A l'aide d'une modélisation éléments finis d'un tel miroir nous avons réalisé des modifications locales de la structure du miroir pour adapter ses déformations aux capacités de correction de l'optique activeTo meet the challenges of Earth observation and astronomy, future space observatories will require telescopes of several meters in diameter. The various space environment constraints will induce deformations and misalignments of the telescope mirrors, thus degrading the optical quality of observations. The integration of active optics, used since the late 80s for alignment and preservation of the optical quality of the ground telescopes, becomes mandatory. Such a system consists of three elements: a measuring device, a correction set-up and a control loop which links both previous elements.The research works presented in this PhD thesis focus, on one hand, on the development of a perturbations estimator minimizing the residual wave front in the telescope field of view. The analysis of this estimator and more generally of the ultimate performance of a space active optics system enabled us to highlight the impact of high spatial frequencies on optical quality. On the other hand, the presence of such high frequencies due to the primary mirror supports print through, urged us to evaluate the possibilities of their reduction in the case of large mirrors. Using a finite element model of such a mirror, we made local modifications of the mirror structure to adapt its deformation to the correcting capabilities of active optics
50
Anderson, Craig Stuart. "Broadband Radio Polarimetry as a Probe of Magnetised Plasma Towards Powerful Radio Sources." Thesis, The University of Sydney, 2016. http://hdl.handle.net/2123/16014.
Full textAbstract:
This thesis considers whether “Faraday complexity” — information imprinted as a frequency-dependent signal on linearly polarised radiation by Faraday rotation as it propagates through magnetised cosmic plasmas — can be exploited as an effective probe of magneto-ionised structure in active galactic nuclei (AGNs), radio galaxies, and intervening material. A blind search for Faraday complexity amongst 563 radio sources over 1.3–2 GHz results in a signal-to-noise-limited detection rate of 12%. The Faraday-complex sources are found to preferentially lie behind magnetised, turbulent interfaces between neutral and ionised gas in the Galactic interstellar medium. A targeted survey of 36 objects over 1.3–10 GHz reveals striking Faraday complexity in all of the sample sources. The characteristics of the radio emission, including the spectral index of the radio emission and its linear extent, temporal variation in polarisation, and the Faraday-thickness of emission components, suggests that Faraday complexity arises in the AGNs themselves at these frequencies. The data supply strong constraints on the global magnetised structure of AGN and their jets. Observations of the nearby radio galaxy Fornax A over 1.3–3.1 GHz reveal complex frequency-dependent polarisation structure. Filaments of strong depolarisation are revealed to be real physical structures, likely caused by Kelvin-Helmholtz and/or Rayleigh-Taylor instabilities at the lobe / intergalactic medium interface. Faraday complexity also exists away from the depolarised filaments in the body of the lobe, and I argue that this must be caused by thermal plasma in the lobe that is well-separated from the synchrotron-emitting plasma. I conclude that broadband observations of Faraday complexity do indeed provide a singular probe of magnetised plasmas in diverse cosmic environments.