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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
371

Cyclotron Production of Technetium-99m

Gagnon, Katherine M Unknown Date
No description available.
372

Extracellular S100A4 induces human thyroid cancer cell migration

Medapati, Manoj Reddy 28 August 2013 (has links)
Human thyroid cancer is the most commonly occurring cancer of the endocrine gland having good survival rate, but some patients show recurrence with an invasive phenotype and treatment failures. The mechanisms behind this invasive phenotype are not well understood in TC. Previously our group has identified a pro-migratory role of relaxin-like peptides in thyroid cancer that is mediated by S100A4. We have observed in human TC cells that extracellular S100A4 induces migration and activates ERK1/2, JNK/SAPK and NFkB signaling pathways. Employing immunohistochemistry and immunofluorescence we have identified the expression of RAGE in human TC primary cells, cell lines, and in tumor tissues but not in normal thyroid tissues. We showed that S100A4 binds to RAGE in TC cells and that RAGE and its cytoplasmic partner Dia-1 mediate the S100A4-induced migration of TC cells. This study identified a crucial role of RAGE in TC cell migration induced by S100A4.
373

A study of the effects of oxygen environment on the stoichiometry, phase assemblage and stability of BiSCCO 2212 and 2201 using EPMA

Rowan, Fraser S. January 2001 (has links)
A method of performing accurate oxygen analysis on cuprate based superconducting materials was established using electron probe micro analysis (EPMA). A range of YBa<sub>2</sub>Cu<sub>3</sub>O<sub>δ</sub> ceramics with varying oxygen concentration were used to test the method. Using YBCO as a reference material, a suitable standard for oxygen analysis of Bi<sub>2</sub>Sr<sub>2</sub>CaCu<sub>2</sub>O<sub>δ</sub> (BiSCCO-2212) materials was obtained. This standard was used to perform full elemental analysis of a range of BiSCCO-2212 crystals, post annealed in pO<sub>2</sub>'s between 10<sup>-5</sup>-2atm. When the average Cu valence of each crystal was calculated and plotted as a function of the critical temperature (T<sub>c</sub>) for each crystal, it was shown that BiSCCO-2212 materials conformed to the 'universal' trend illustrated by most other HTS and did not exhibit anomalous behaviour as had been previously believed. The phase assemblage and superconducting properties of BiSCCO-2212 Ag-clad multifilamental wires, prepared using the powder-in-tube (PIT) method by BICC, were studied as a function of a time/temperature profile. pO<sub>2</sub> of the processing atmosphere was found to be the predominant factor in determining the stoichiometry of the 2212 phase within wires. The phase assemblage is not simply a function of pO<sub>2</sub> as previously believed and can be controlled, in part, by the post annealing temperature. Homogenisation of the phase assemblage in BiSCCO-2212 Ag-clad wires can be achieved by prolonged heating (96hrs) at an appropriate temperature. An investigation into the 10K superconducting BiSCCO phase has shown the Sr-rich solid solution to extend towards the ideal stoichiometry of 2:2:1 (Bi:Sr:Cu) with increasing pO<sub>2</sub>. Using a combination of high pO<sub>2</sub> (60atm) to achieve the appropriate Bi:Sr stoichiometry followed by post annealing in N<sub>2</sub> to adjust the oxygen content, it was possible to prepare single-phase ceramics of stoichiometry Bi<sub>2.11(2)</sub>Sr<sub>1.90(2)</sub>Cu<sub>0.99(2)</sub>O<sub>δ</sub> with a T<sub>c</sub>=10.5K(5).
374

High temperature superconducting thin films and quantum interference devices (SQUIDs) for gradiometers

Graf zu Eulenburg, Alexander January 1999 (has links)
No description available.
375

Extracellular S100A4 induces human thyroid cancer cell migration

Medapati, Manoj Reddy 28 August 2013 (has links)
Human thyroid cancer is the most commonly occurring cancer of the endocrine gland having good survival rate, but some patients show recurrence with an invasive phenotype and treatment failures. The mechanisms behind this invasive phenotype are not well understood in TC. Previously our group has identified a pro-migratory role of relaxin-like peptides in thyroid cancer that is mediated by S100A4. We have observed in human TC cells that extracellular S100A4 induces migration and activates ERK1/2, JNK/SAPK and NFkB signaling pathways. Employing immunohistochemistry and immunofluorescence we have identified the expression of RAGE in human TC primary cells, cell lines, and in tumor tissues but not in normal thyroid tissues. We showed that S100A4 binds to RAGE in TC cells and that RAGE and its cytoplasmic partner Dia-1 mediate the S100A4-induced migration of TC cells. This study identified a crucial role of RAGE in TC cell migration induced by S100A4.
376

Determination Of Hydraulic Parameters Of Semi-infinite Aquifers Using Marquardt Algorithm

Taskan, Cuneyt 01 January 2004 (has links) (PDF)
In this study, transmissivity and storage coefficient of a semi-infinite, confined, homogeneous and isotropic aquifer, where the flow is one-dimensional and linear, are determined using Marquardt algorithm, considering two independent cases: constant drawdown in the adjacent stream / or constant discharge from the aquifer due to pumping at a constant rate. In the first case piezometric head and discharge measurements are utilized. Hydraulic diffusivity, which is the ratio of transmissivity to storage coefficient, is determined from piezometric head measurements / whereas their product is determined from discharge measurements. Then, the two parameters are calculated easily. In the second case piezometric head observations are utilized only and transmissivity and storage coefficient are determined simultaneously. Convergence to true values is very fast for both cases even for poor initial estimates. Three examples, two using synthetic data for both cases and one using actual field data for the second case, are presented. Conventional type-curve matching method is used for comparison of the results. It is observed that the results of Marquardt algorithm are in a reasonable agreement with those of type-curve matching method.
377

Generation Of Surface Waves Due To Sudden Movements At The Sea Bottom

Kirlangic, Ozgur Ulas 01 May 2004 (has links) (PDF)
A mathematical model is developed for investigating time dependent surface deformations of a hydrostatic water volume, when it is subjected to a sudden partial collapse or rise of the sea bottom. The model solves two-dimensional Navier-Stokes Equations on a vertical plane numerically by using Marker and Cell Method (MAC) for viscous and compressible fluid including all the nonlinear effects in the solution. For demonstration, a vertical motion was given to a section in a hypothetical reservoir bed within a short time period and the resulting velocity and pressure fields and the surface profile of the water body are obtained. Computational and physical aspects are discussed.
378

Effect Of Wave Grouping,spectral Shape And Exreme Waves In A Wave Train On The Stability Of Rubble Mound Breakwaters

Ozbahceci Oztunali, Berguzar 01 July 2004 (has links) (PDF)
There are some empirical formulas used in the design of rubble mound breakwaters to find the weight of armour layer stone. The effect of wave grouping and spectral shape could not put into these design formulas since their effects are still under question. The influences of wave groups and spectral shape on the stability of rubble mound breakwaters have been investigated by several researchers up to now. However, results were not conclusive in these researches, where different wave grouping and spectral shape parameters were used. This study aims to investigate the influences of wave groups and spectral shape on the stability of rubble mound breakwaters by means of hydraulic model experiments. According to the result of the experiments, the damage to breakwater armour layer is almost same for different spectrum shapes and pronounced wave grouping, under the condition of similar wave statistics. Experiments also indicated that the wave trains with same significant wave height, H1/3, but with different distribution of the heights of extreme waves which were defined as wave heights higher than H1/3 in this study, cause different damage levels. Based on these results, extended experiments were conducted to observe the effect of heights of extreme waves in a wave train on the stability of rubble mound breakwaters. Results of the experiments showed that the higher the extreme waves are, the more destructive the wave train is. By carrying experimental results into design conditions, it was shown that a wave train with high extreme waves may affect the design weight of armour stone. Finally, in order to achieve more practical tools for engineering applications, occurrence probabilities of extreme waves under different spectral shapes were obtained by a numerical simulation. As a result, for different occurrence probabilities of extreme waves under the most widely used spectrums of PM and JONSWAP, necessary weight of armour stone was given in a range comparing with the formula of Meer. Moreover, it was noted that the spectral shape indirectly affects the stability not due to the wave grouping but due to the extreme waves in a wave train since the occurrence probability of the high extreme waves becomes higher as the spectral shape becomes narrower under same significant wave height condition.
379

A Case Study On The Stability Of Berm Type Coastal Defense Structures

Fiskin, Gokce 01 December 2004 (has links) (PDF)
Coastal defense structures have primary importance from obtainabilty of resources and benefits served by the coastal regions point of view. However, the construction of coastal defense structures demand a high amount of investment. Therefore, in order to reduce the risk of collapse of these structures, model studies should be carried during the design process. In this study, model investigations were carried out on Eastern Black Sea Highway Project regarding the serviceability and damage thus stability parameters. 5 different models were constructed as berm type rubble-mound breakwaters using Van Der Meer&rsquo / s approach and berm design guidelines, with a scale of 1/31.08 and they were tested both for breaking and non-breaking waves. The experiments took place in the Coastal and Harbor Engineering Laboratory of the Middle East Technical University, Civil Engineering Department. The models were constructed and tested with different berm widths and armor stone sizes forming the back armor layer in order to examine the effect of these design parameters on the stability and serviceability of the coastal defense structure to obtain the optimum alternative cross-section. Cumulative damage was minimum for the cross-section constructed with berm width 15 m assigning the width of the prototype. Water spray and run-up values were also not significant. The test results were confirming with Van Der Meer design approach.
380

Coastal Scenic Assesment Using Fuzzy Logic Approach

Karakaya, Selami Tansel 01 November 2004 (has links) (PDF)
This thesis analyzes the coastal landscape evaluation that is strongly rooted in the man-environment tradition. Scenery is a natural resource and managers need to attempt the evaluation of scenic resources in an objective and quantitative way that can be utilized mainly in landscape preservation and protection. The thesis will try to find an objective way in evaluation of the coastal scenery by using fuzzy logic mathematics and public perception studies. Using mathematical model developed within the frame work of the present study the selected 22 sites in Turkey were evaluated and then classified.

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