Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 32 for “"Beam size"”.
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The strength of glulam beams with holes - A probabilistic fracture mechanics method and experimental tests
… and methods for strength analysis of glulam beams with holes. Test results and methods for strength analysis available in literature are compiled and discussed. The methods considered comprise both code strength design methods and more general methods for strength analysis. New strength tests …
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Progress towards cavity induced transparency
… I conclude with preliminary data on the waist-size of the sideprobe beam on the atomic ensemble trapped in an optical lattice. We measure the beam size at our ensemble to be around 5pm. Although we have not yet measured the size of the atomic cloud, we expect this beam size to be smaller than …
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Bayesian model selection with applications to radio astronomy
… separations that are much smaller than the naive beam size at high signal to noise. In the first part, the idea is to create a supermodel by combining two models using a hyperparameter, which we call α. Setting α = 0 or 1 switches each of the models off. Hence, the ratio of the posterior of α at …
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Coherence Control and Measurement at the CLS Using X-ray Interferometry
… and coherence, emerging challenges arise in beam diagnostic tools that accurately monitor and control the spatial degree of coherence. MBA lattice designs in modern fourth generation light sources significantly reduce the transverse beam size, posing challenges for beam monitoring due to …
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Behaviour of long span composite beams with precast hollow-core slabs
… hollow-core concrete slabs with Fabsec steel beams in composite construction has had little research conducted in this area. The main purpose of the research is to develop an understanding into the behaviour of this form of construction and to demonstrate the advantages of using Fabsec beams …
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Analytical investigation of composite diaphragms strength and behavior
… analyzed to failure. Parameters studied included beam size and orientation, panel dimension, connector type and distance, slab opening, yield plateau, and beam connection flexibility. Shear connector, deck-to-concrete interface, and beam connection were the components modeled non-linearly. …
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Ion Bunch Formation Strategies for the JLEIC Collider
… JLEIC, includes construction of a new ion beam accelerator complex. To achieve the required luminosity, the JLEIC ion collider requires unprecedentedly short ion bunches of 1 cm length at a high repetition frequency of 476 MHZ. However, only much longer ion bunches are formed by the ion …
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Application-driven Intersections between Information Theory and Machine Learning
… in machine translation for selecting the beam size in beam search.
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Sources of Quality Uncertainty in Laser Powder Bed Fusion Metal Additive Manufacturing
… We show that small variations in the laser beam size, power, scan speed, and powder bed thickness results in significant changes in the SLM dynamics. Third, this work focuses on identifying the uncertainty due to particle size distribution (PSD) on the resulting Ti6Al4V powder’s flowability. …
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Observing galaxies in the Southern Filament of the Virgo Cluster with KAT-7 and WSRT
… region. Despite the different observing time and beam size of the two telescopes, we reach similar column density sensitivities of NHI ~1 X 10¹⁸ atoms cm⁻² over 16.5kms⁻¹. With a new approach, we combine the two observations to map both the large and small scale structures. We detect, out to an …
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PROTON IRRADIATION SAMPLE HOLDER II (PISH II)
… of the sample along with monitoring the beam current during experiments. This thesis explores the design and implementation of a new sample holder named PISH II. It improves upon the accuracy of temperature and beam current measurements by adding a thermal camera and secondary electron …
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The dynamics and optimization of the radiation of a femtosecond diode pumped Yb:KGW laser /
… in the optical stretcher depends only on the beam size and the diffraction grating grooves density and does not depend on the bandwidth of the pulse. In order to optimized the compression of amplified pulses we have also proposed and experimentally tested a new design of single shot …
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Characterization and application of simultaneously spatio-temporally focused ultrafast laser pulses
… the relative spectral position as well as beam size can be deduced. Temporal characterization is done by dispersion scan, where a second harmonic crystal through the beam focus. Combining the unknown phase of the pulse with the known phase (a result of angular dispersion) allows the unknown …
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Development of correction algorithm for pulsed terahertz computed tomography (THz-CT)
… in the THz range can severally refract THz beams which probe the internal structure of a sample during the acquisition of tomography data. Refractive effects lead to anomalously high local absorption coefficients in the reconstructed image near the material's boundaries. Three refractive …
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Applications of long storage time optical cavities
… techniques, we studied loss dependence on laser beam sizes and positions. Within the 1 to 3 mm beam spot size we measured, we found that the mirror loss is almost constant at around 5 ppm, and that the loss depends more on the beam position on the mirror than on the beam size 121. While …
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Characterization of Ultra-High Performance Concrete Tension Behavior Using Different Test Methods
… direct-tension tests and 40 four-point bending beam specimens with different cross-sections. The experimentally obtained moment vs. curvature responses from four-point bending tests were used to calculate the tensile stress-strain response of UHPC. These results were then compared to the ones …
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Electron beam sizes and lifetimes at MAX II and MAX III
… thesis the transverse and longitudinal electron beam sizes and the electron beam lifetime limitations in electron storage rings are discussed and the methods used at MAX-lab to measure them are described. The thesis describes how measurements of the electron beam sizes and lifetimes were used to …
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TRANSVERSE CHARACTERIZATION AND CONTROL OF BEAMS WITH SPACE CHARGE
… of the transverse phase space of beams is a fundamental requirement for particle accelerators. As accelerators shift toward higher intensity beam regimes, the transverse dynamics of beams becomes more influenced by interparticle forces known as the space charge forces. Therefore, …
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Treatment of brain cancer and ischaemic stroke utilising High Intensity Focus Ultrasound (HIFU) guide with MRI
… temperature). It was found that the larger the beam area the larger the dissolved clot volume. Also, the lower the frequency, the larger the volume of the dissolved clot. The results reported herein point to the use of frequency around 0.5 MHz and pulsing to optimize thrombolysis and skull …
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Reinigen von Tiefdruckzylindern mit Excimerlaserstrahlung
… rotating in this machine. Meanwhile the laser beam strikes radial onto the surface of the cylinder and moves in a parallel way to the axis of the cylinder. The optical beam guiding and shaping system is designed as a "flying optic". It includes a reflective beam homogenizer and a zoom objective …
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