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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.
31

A Simple and Cost Effective Raman-Fluorescence Spectrometer

Marshall, Frank E., Brinker, Katelyn R., Chiaventone, Owen, Pride, Michael A., Walker, Zachary, Rojo, Michelle 10 1900 (has links)
ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV / Research, design, construction, and operation of a portable mixed Raman and Fluorescence type spectrometer will be presented. The spectrometer was used on a wheeled vehicle which competed in the University Rover Challenge sponsored by the Mars Society. It uses a 50 mW, 532 nm continuous wave laser to probe a sample of soil for bacteria or biomarkers. The device costs 2,000 USD, weighs 1.4 kg and is 23 cm x 23 cm x 10 cm in size. Results from the competition, complications of analyzing mixed Raman-Fluorescence spectra via digital signal processing, and future ideas and improvements will also be discussed.
32

Development and application of some techniques for proton and sodium NMR

Barlow, G. K. January 1988 (has links)
No description available.
33

The real-time optimisation of electron spectrometers

Howell, S. January 1985 (has links)
No description available.
34

Spectroscopic imaging with uncooled microbolometer camera and step-scan FTIR

Malamas, Sitthichai. 12 1900 (has links)
The purpose of this thesis research was to explore the feasibility of spectral imaging using a microbolometer infrared camera and a step-scan Fourier transform infrared spectrometer (FTIR). Spectral imaging is usually carried out using cryogenically cooled semiconductor based focal plane arrays (FPAs) which provide higher sensitivity compared to microbolometer FPAs based on thermal sensors. The key advantage of spectral imaging is the ability to extract spatial variations of spectral information. During the measurement, images were collected as the moving mirror of the FTIR stepped across the zero crossings of the on-axis portion of the interferogram. The preliminary data indicate that interferograms can be successfully recorded using the microbolometer camera, and that data from individual pixels of the camera showed the expected intensity profile. The interferograms from the individual pixels were inverse Fourier transformed to recover the intensity of the broadband infrared source of the FTIR at different pixels. The initial data showed relatively low signal to noise ratio indicating that signal averaging is necessary at each mirror step by collecting several images as well as optimizing the image collecting optics.
35

The construction of a near-infrared laser spectrometer for high resolution spectroscopy.

January 2003 (has links)
Cheng Pui-kwan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2003. / Includes bibliographical references (leaves 69-71). / Abstracts in English and Chinese. / TITLE PAGE --- p.i / THESIS COMMITTEE --- p.ii / ABSTRACT (ENGLISH) --- p.iii / ABSTRACT (CHINESE) --- p.iv / ACKNOWLEDGEMENTS --- p.v / TABLES OF CONTENTS --- p.vi / LIST OF FIGURES --- p.viii / LIST OF TABLES --- p.xi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter Chapter 2 --- A High Resolution Near Infrared Laser Spectrometer: the Construction --- p.4 / Chapter Section 2A --- Basic Principle of LASER --- p.4 / Chapter Section 2B --- Properties of Laser Radiation --- p.7 / Chapter Section 2C --- Common Laser Sources --- p.11 / Chapter Section 2D --- The Construction of a New Infrared Spectrometer --- p.11 / Chapter Section 2E --- Frequency Calibration and Data Acquisition System --- p.19 / Chapter Section 2F --- Spectrometer Performance Tests --- p.26 / Chapter Section 2G --- Summary --- p.36 / Chapter Chapter 3 --- Study of Pressure Broadening of Water Using Cavity Enhanced Absorption Spectroscopy --- p.37 / Chapter Section 3A --- Background --- p.37 / Chapter Section 3B --- Experimental Apparatus --- p.43 / Chapter Section 3C --- Results and Discussion --- p.50 / Chapter Chapter 4 --- Concluding Remarks --- p.68 / REFERENCES --- p.69
36

An x-ray double crystal spectrometer study of singly-ionized sodium-implanted magnesium oxide

Workman, Ricky Lynn January 2011 (has links)
Digitized by Kansas Correctional Industries
37

New X-ray counter spectrometer techniques

Lang, Andrew January 1953 (has links)
No description available.
38

Development of Instrumentation and Methods for Positron Spectroscopy of

Nissilae, Jaani 00 December 1900 (has links) (PDF)
No description available.
39

Fundamental studies of MALDI with an orthogonal TOF mass spectrometer

Qiao, Hui 30 January 2009 (has links)
The interaction between the matrix and analyte molecules are studied with a high resolution MALDI imaging technique in an orthogonal-injection TOF mass spectrometer. The analyte incorporation and distribution patterns have been clearly demonstrated. Purified protein analytes were found to be homogeneously incorporated in large single crystals of DHB and sinapinic acid matrices, with no evidence for preferred crystal faces. Segregation of some species was observed and appeared to correlate with analyte hydrophobicity, and to a lesser extent analyte mass or mobility. The influence of incident laser parameters on sensitivity in MALDI has been investigated using orthogonal-injection time-of-flight (TOF) instruments. A qualitative comparison was first made between the beam profiles obtained with a N2 laser and a Nd:YAG laser using 2-m long optical fibers. The N2 laser gives better sensitivity, consistent with a more uniform fluence distribution and therefore better coverage of the N2 laser profile. Most of the difference disappears when a 30-m long fiber is used or when the fibers are twisted during irradiation to smooth out the fluence distribution. In more systematic measurements, the total integrated ion yield from a single spot (a measure of sensitivity) was found to increase rapidly with fluence to a maximum, and then saturate or decrease slightly. For a fluence near threshold, the integrated yield has a steep (cubic) dependence on the spot size, but the yield saturates at higher fluence for smaller spots. The area dependence is much weaker (close to linear) for fluence values above saturation, with the result that the highest integrated yields per unit area are obtained with the smallest spot sizes. Finally the detection properties of the MCP detector were studied with a hybrid MCP and CuBe venetian blind converter detector. The measurements show that the detection efficiency of the MCP drops with the increasing of ion mass and the decreasing of the ion energy. The secondary electron emission coefficient of the MCP shows a linear dependence on mass and a power law dependence on velocity (~ 3.2). No clear velocity threshold is observed for secondary electron emission. / May 2009
40

Precise mass measurements of Cf252 fission fragments with the Canadian penning trap mass spectrometer (CPTMS)

Wang, Yuyan 28 March 2007 (has links)
The Canadian Penning Trap Mass Spectrometer (CPTMS) located at the ATLAS (Argonne Tandem Linear Accelerator System) facility of Argonne National Laboratory makes precise mass measurements on both stable and unstable isotopes. A 252Cf fission source has been used as the ion source for the unstable isotope mass measurements. This thesis concentrates on the mass measurements of the fission fragments from the 252Cf fission source using the CPTMS system. It is the first time that the masses of such fission fragments have been measured with a mass spectrometer. The masses of 108Tc, 108Ru, 109Ru and 110Ru have been measured to a precision of 10-7. The results have been compared to exiting mass measurements and the Atomic Mass Evaluation (AME2003). In general good agreement between this work and existing data is realized. A few discrepancies are identified. / October 2006

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