• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 501
  • 486
  • 333
  • 276
  • 58
  • 34
  • 26
  • 16
  • 12
  • 10
  • 8
  • 4
  • 3
  • 3
  • 3
  • Tagged with
  • 2164
  • 403
  • 297
  • 291
  • 216
  • 202
  • 154
  • 135
  • 131
  • 122
  • 118
  • 118
  • 116
  • 112
  • 102
  • 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.
1

Development of tandem time-of-flight instrumentation for the examination of prompt photodissociation of peptides using 193-nm radiation

Morgan, Joseph William 12 April 2006 (has links)
The design and incorporation of a decelerating/accelerating cell into a reflectron time-of-flight mass spectrometer is described for the examination of promptly-formed photodissociation products of peptide ions. The analytical utility of prompt 193-nm photodissociation was investigated for model peptides that resemble tryptic digest products, as well as for two sets of homologous peptides. The first of these sets include bradykinin, several bradykinin fragments, and two bradykinin mutants with substituted amino acids. Fragment ion spectra of [M + H]+, [M + Na]+, and [M + Cu]+ were collected for each of these peptides. The second set of homologous peptides has the sequence XVGVAZG, where variable amino acid X was either arginine, histidine, or lysine, and amino acid Z was either proline, serine, or glycine. Photofragment ion spectra obtained using the new mass spectrometer are compared to results of high energy collision induced dissociation (CID) acquired on a high performance commercial instrument. The advantages and disadvantages of prompt photodissociation relative to CID are discussed, as well as the advantages of photodissociation using the modified instrument geometry versus that of the post-source decay focusing method.
2

A multimodal spectrometer for Raman scattering and near-infrared absorption measurement

Wang, Wenbo 05 September 2012 (has links)
In food and pharmaceutical industries, the compositional complexity of raw materials and products promotes the use of multiple spectroscopic techniques. Availability of complementary methods, e.g., infrared absorption and Raman, is highly desirable. A multimodal Raman/NIR spectroscopic device was proposed. The device offered fast, non-destructive measurement, and remote sensing capability. A prototype was built. Spectral range covered 300-2600 cm-1 for Raman channel. Wavelength accuracy was better than 0.57 nm. Spectral resolution was better than 14.39 cm-1 (1 nm) for Raman (NIR) channel. Spectral response linearity was better than 0.998. Instrumental stability was better than 0.72% (0.39%) for Raman (NIR) channel. The device was applied to quantify ethanol aqueous solutions (2%-10% (v/v)). Quantitation results gave a root mean squared error of prediction (RMSEP) of 0.45% (v/v). Calibration using NIR absorbance spectra produced a RMSEP value of 0.49% (v/v). Raman technique offered the most succinct calibration model using peak height at 882.29 cm-1. Quantitation of ovalbumin (8%-16% (w/v)) in aqueous solutions and denatured states was also attempted. Stepwise multiple regression was performed using Raman peaks at 1243.35, 1448.68, 1662.66, and 1667.78 cm-1, which produced RMSEPs of 1.05 % (w/v) for ovalbumin solutions and 0.74 % (w/v) for ovalbumin gels. Conformational change of ovalbumin upon thermal denaturation was studied using the height and area ratios between peaks at 1243.35 and 1662.66 cm-1. Thermal denaturation of ovalbumin occurred at 70 °C and extensive formation of anti-parallel β-sheet structure was found at 90 °C. The unique capability of this multimodal device was proven by first performing data fusion of Raman and NIR spectra for quantitation. Using the same ethanol spectra set gave a more complicated model and a higher RMSEP of 0.73% (v/v). However, important variables in fused spectra corresponded well with the spectral signatures of ethanol and water. Two-dimensional correlation spectra were calculated using concentration as the external perturbation. The autopower spectra revealed features pertinent to those of the analytes. Heterospectral correlation analysis was carried out on Raman/NIR spectra of ethanol aqueous solution. Raman peaks at 882.29 and 1454.00 cm-1 agreed with the NIR absorption feature around 906.18 nm.
3

A multimodal spectrometer for Raman scattering and near-infrared absorption measurement

Wang, Wenbo 05 September 2012 (has links)
In food and pharmaceutical industries, the compositional complexity of raw materials and products promotes the use of multiple spectroscopic techniques. Availability of complementary methods, e.g., infrared absorption and Raman, is highly desirable. A multimodal Raman/NIR spectroscopic device was proposed. The device offered fast, non-destructive measurement, and remote sensing capability. A prototype was built. Spectral range covered 300-2600 cm-1 for Raman channel. Wavelength accuracy was better than 0.57 nm. Spectral resolution was better than 14.39 cm-1 (1 nm) for Raman (NIR) channel. Spectral response linearity was better than 0.998. Instrumental stability was better than 0.72% (0.39%) for Raman (NIR) channel. The device was applied to quantify ethanol aqueous solutions (2%-10% (v/v)). Quantitation results gave a root mean squared error of prediction (RMSEP) of 0.45% (v/v). Calibration using NIR absorbance spectra produced a RMSEP value of 0.49% (v/v). Raman technique offered the most succinct calibration model using peak height at 882.29 cm-1. Quantitation of ovalbumin (8%-16% (w/v)) in aqueous solutions and denatured states was also attempted. Stepwise multiple regression was performed using Raman peaks at 1243.35, 1448.68, 1662.66, and 1667.78 cm-1, which produced RMSEPs of 1.05 % (w/v) for ovalbumin solutions and 0.74 % (w/v) for ovalbumin gels. Conformational change of ovalbumin upon thermal denaturation was studied using the height and area ratios between peaks at 1243.35 and 1662.66 cm-1. Thermal denaturation of ovalbumin occurred at 70 °C and extensive formation of anti-parallel β-sheet structure was found at 90 °C. The unique capability of this multimodal device was proven by first performing data fusion of Raman and NIR spectra for quantitation. Using the same ethanol spectra set gave a more complicated model and a higher RMSEP of 0.73% (v/v). However, important variables in fused spectra corresponded well with the spectral signatures of ethanol and water. Two-dimensional correlation spectra were calculated using concentration as the external perturbation. The autopower spectra revealed features pertinent to those of the analytes. Heterospectral correlation analysis was carried out on Raman/NIR spectra of ethanol aqueous solution. Raman peaks at 882.29 and 1454.00 cm-1 agreed with the NIR absorption feature around 906.18 nm.
4

Grundsätze und Entwicklung der Instrumentation in der vorklassischen und klassischen Sinfonie

Reese, William Heartt, January 1939 (has links)
Inaug.-Diss.--Friedrich-Wilhelms-Universität, Berlin. / Vita. "Literaturverzeichnis der neueren Bücher": p. 174-175.
5

Grundsätze und Entwicklung der Instrumentation in der vorklassischen und klassischen Sinfonie

Reese, William Heartt, January 1939 (has links)
Inaug.-Diss.--Friedrich-Wilhelms-Universität, Berlin. / Vita. "Literaturverzeichnis der neueren Bücher": p. 174-175.
6

PORTABLE MEDICAL INSTRUMENT FOR OBJECTIVELY DIAGNOSING HUMAN TINNITUS

Ahmed, Mohamed E. 01 May 2010 (has links)
This thesis presents designs of portable medical instruments to diagnose human tinnitus. At the present time, portable medical instruments are used everywhere for almost all kinds of daily health needs. Those high-performance instruments are used in medical facilities, hospitals, and clinics, and on the personal use level, as patients need them. Nowadays the digital means to design those instruments have become very important, and it's our goal to make use of the technology to upgrade and make those designs fast, accurate, easy to use, and inexpensive, so all people with need of those devices will be able to obtain them. At this time, there are many questions regarding tinnitus, but few definitive answers. Since it is still not fully understood, many comprehensive studies and analysis were carried out to present a complete model for the instruments.
7

Computer Program Instrumentation Using Reservoir Sampling & Pin++

Upp, Brandon E. 08 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / This thesis investigates techniques for improving real-time software instrumentation techniques of software systems. In particular, this thesis investigates two aspects of this real-time software instrumentation. First, this thesis investigates techniques for achieving different levels of visibility (i.e., ensuring all parts of a system are represented, or visible, in final results) into a software system without compromising software system performance. Secondly, this thesis investigates how using multi-core computing can be used to further reduce instrumentation overhead. The results of this research show that reservoir sampling can be used to reduce instrumentation overhead. Reservoir sampling at a rate of 20%, combined with parallelized disk I/O, added 34.1% additional overhead on a four-core machine, and only 9.9% additional overhead on a sixty-four core machine while also providing the desired system visibility. Additionally, this work can be used to further improve the performance of real-time distributed software instrumentation.
8

Instrumentation d'un tunnel hydrodynamique pour la caractérisation de turbines à flux transverse / Instrumentation of a water tunnel for the characterization of transverse flow turbine

Dellinger, Nicolas 22 July 2011 (has links)
Le projet HARVEST a pour objectif de développer un nouveau type de turbomachine, dite hydrolienne, composée de turbines à flux transverse. Les travaux menés lors de cette thèse concernent l'instrumentation de la veine d'essai d'un tunnel hydrodynamique : il s'agit de caractériser expérimentalement les performances hydrodynamiques de maquettes de telles turbines et de mesurer en particulier l'évolution angulaire des efforts hydrodynamiques sur les pales. Ces efforts sont mesurés par un dispositif à capteurs piézoélectriques associé à un dispositif de régulation et de transformation d'énergie par génératrice de courant synchrone. Le processus de conception ainsi que les étapes de mise au point et de caractérisation de ces sous-ensembles sont ensuite exposés. Enfin, une campagne d'essais permet d'apporter des conclusions d'ordre méthodologique et technologique sur les travaux présentés. / The HARVEST project's objective consists in developing a new type of turbo- machine, named hydrolien, made of inverse flux turbines. The research conducted in this dissertation deals with the implementation of the stream tube of a hydrodynamic tunnel; it consists in the experimental determination of hydrodynamic performances of models designed for the turbines and, more specifically, of measuring the angular evolution of hydrodynamic efforts on the blades. The efforts were measured through piezoelectric sensors device, along with a regulatory and transformational energy device, by way of synchronous power generator. The elaborations of the design, as well as the different steps of adjustments and characterization of the subsets, are then described. Finally, a series of experiments leads to methodological and technological conclusions concerning the entire project.
9

Computation and display of EEG spectral and event-related desynchronization topographic maps

Andrew, Colin Murray 06 April 2017 (has links)
No description available.
10

High-Speed Distributed Digital Instrumentation System

Donlan, Brian, Baumgartner, Michael 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California / An distributed architecture for high-speed digital and analog instrumentation is discussed. This architecture supports the collection, formatting, recording of both conventional telemetry (analog & PCM) and high-speed digital data. Remotely located instrumentation data interface units provide data acquision close to the data sources. The remotely located units are connected via high-bandwidth fiber optic links to a central formatting and recording unit. Data is recorded on digital rotary head recorders. Graphic workstations provide visual data displays for test control and monitoring. This system was developed to handle the high-speed data acquision requirements of advanced avionics sensor and seeker systems, however, it provides the basis for many other applications.

Page generated in 0.1546 seconds