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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.
1

Miniatur-Fixpunktzellen als Basis selbstkalibrierender elektrischer Berührungsthermometer

Boguhn, Dirk. January 2002 (has links) (PDF)
Ilmenau, Techn. Universiẗat, Diss., 2002.
2

White Americans' Affect Toward African Americans: Predictive Power on Political Behavior and Measurement Problems

Gottemoller, Paul Gerard 01 August 2011 (has links)
The purpose of this study is to investigate the impact white affect toward African Americans has on whites' racial policy opinions. The study also identifies the difficulty of measuring affect in the traditional feeling thermometer. Moreover, the study introduces and tests a new method for measuring affect that improves interpersonal comparability of reported affect by anchoring the respondents' self-placements. The study investigates the changes in the relationship between white affect toward African Americans and racial policy opinions of presidential election years between 1964 and 2008. Furthermore, the study tests a new method for measuring affect by having respondents rate where they believe groups representing points on an ordinal scale would belong on the scale. The method allows for an adjustment of the respondents' self-placement in relation to where the respondent places the group. The findings contained here show that affect can be an important predictor of white racial policy opinion and the strength of affect can vary over time. In addition, the measurement of affect can be improved by utilizing anchoring objects in a survey to clarify the ordering of the scale for the respondents, as well as allowing for a reallocation of scores.
3

A New Standard for Temperature Measurement in an Aviation Environment

Grossman, Hy 10 1900 (has links)
ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California / Accurate temperature measurement is an essential requirement in modern aircraft data acquisition systems. Both thermocouples and Platinum resistance temperature detectors (RTD) are used for this purpose with the latter being both more accurate and more repeatable. To ensure that only the sensor limits the accuracy of a temperature measurement, end-to-end system accuracy forward of the sensor, should be significantly greater than that of the sensor itself. This paper describes a new digital signal processing (DSP) based system for providing precision RTD based temperature measurements with laboratory accuracy in an aviation environment. Advantages of the new system include, true 3-wire RTD measurement, linear temperature output, on-board ultra-precision resistance standards and transparent dynamic calibration.
4

Cryogenic temperature sensor investigation

Bateman, Rodney William January 1999 (has links)
No description available.
5

Quantitative impurities effects on temperatures of tin and aluminium fixed-point cells

Petchpong, P. January 2009 (has links)
The International Temperature Scale of 1990 (ITS-90) defines the present S.I.(“System International”) means of measuring temperature. The ITS-90 uses the freezing points of metals to define temperature fixed points. It also uses long-stemplatinum resistance thermometers to interpolate between the fixed points from 660 °Cdown to 84 K (if one includes the Argon triple point). Impurities are a major source of uncertainty in the fixed point temperature (of the order of 1 mK). And a better understanding of the impurity effect is required to improve top-level metrologicalthermometry. Most historical experiments with impurities have worked at a muchhigher levels of impurities – say of the order of 100ppm - and in arrangements that are not used on a day-to-day basis in a metrology laboratory. This thesis describes the deliberate doping of tin and aluminium, each with three different impurities and the effects of these on the temperature of the tin and aluminium liquid-solid phase transitions. The impurities, of the order of 1-30 ppm,were Co, Pb and Sb in the tin and Cu, Si and Ti in the aluminium. The tin and aluminium samples were in the form of ~0.3 kg ingots that would normally be used to realise an ITS-90 fixed point. Measurements were made using equipment normally available in a metrological thermometry laboratory, rather than using specially prepared samples. The samples were chemically analysed (by Glow Discharge Mass Spectrometry(GD-MS)) before and after the doping. Using the amount of dopants introduced,and/or the chemical analysis data, the measured temperature changes were compared with those interpolated from the standard text. The experimental undoped liquid-solid transition curves were also compared against theoretical curves (calculated from atheoretical model MTDATA). The results obtained did not disagree with the Hansen interpolated values (though there was considerable uncertainty in some of the measurements (e.g. a factor of 2 ormore) due to the measurement of small changes. Within these uncertainties it indicatesthat the Sum of Individual Estimates (SIE) method of correcting for, at least, metal impurities in otherwise high purity metals remain valid. However the results also showed considerable discrepancies between the initial measured and calculated temperature shifts (based on the pre-existing impurities prior to doping) suggesting that there may be impurities that are not (separately) detected by the GD-MS method. There was evidence that the thermal history of the metal phase transitions can cause considerable segregation of some impurities, particularly those likely to increase the phase transition temperature through a peritectic (“positive” impurities), and that the effects of this segregation can be clearly seen on the shape of the melting curves of thetin doped with Sb. Some of the aluminium doped with Ti freezing curves may also show evidence of a“concave up” shape at the start of the freezing curve, as previously calculated by MTDATA, though the effect is not as pronounced. All individual phase transition measurements - made over tens of hours – were repeated at least three times and found to be reproducible, hence providing a real dataset that can be used for comparison with theoretical models still under development.
6

The development of new tools for field and laboratory diagnosis of Pierces Disease

Bryan, Kelly Asbill 15 May 2009 (has links)
Pierce’s Disease (PD), caused by Xylella fastidiosa, is a devastating bacterial disease of grapevines. One of the few control options is roguing. Roguing depends on precise diagnosis of PD in vines. These experiments were conducted to improve available diagnostic protocols and enhance levels of disease control. Plots were selected from four different Texas vineyards with a total of four different varieties (Blanc duBois, Cabernet Sauvignon, Chardonnay, and Merlot). An infrared thermometer was used to take temperature measurements of the vines. Samples were taken of each of these vines at the same time and were tested for X. fastidiosa by culturing, Enzyme-Linked ImmunoSorbent Assay (ELISA), and Quantitative Real-Time Polymerase Chain Reaction (QRT-PCR). ELISA found an increase in plant temperature in samples that tested positive for X. fastidiosa, but QRT-PCR did not. An infrared thermometer could be used to detect asymptomatic vines, but there are several variables to consider such as grape variety and vineyard location. Grape varieties differed significantly in mean temperatures, as did vineyard locations. PD does not seem to have a pattern in which it spreads, although this could be because of the high level of disease incidence in the chosen vineyards. Both the ELISA and QRT-PCR tests have their own pros and cons for X. fastidiosa detection. ELISA takes approximately 6 hours and can be inaccurate in detecting X. fastidiosa. QRT-PCR takes 2-3 hours and is a much more sensitive test. A combination of techniques (PrepMan Ultra® and nucleic acid precipitation) can be used to clean QRTPCR samples when they have degraded and are being affected by inhibitors.
7

The Effect of Cooling the Head to Reduce Brain Temperature on Stress

Knox, Andrew Mark January 2013 (has links)
Stress is associated with a vast array of negative outcomes for both physical and mental health. Based on evidence that stress influences temperature, and that psychology and physiology influence each other, we investigated the novel possibility that reducing brain temperature reduces stress in a sample of 91 university students. We used head fanning to reduce brain temperature and measured this change with an infrared ear thermometer. Participants were randomly assigned so that the fans faced toward half of the participants (cooling condition) and faced away from the other half (non-cooling control condition). Differences in stress between conditions during the Vandenberg and Kuse (1978) Mental Rotations Test were then examined to test the hypotheses that (a) cooling would buffer stress and (b) that this would be mediated by changes in brain temperature, as indicated by ear temperature. Participants in the cooling condition were less stressed (p = .02) and also performed better (p = .03) during the task but neither of these findings were mediated by ear temperature. Thus, some uncontrolled variable(s), and not changes in temperature, may have been responsible for the effect of cooling on stress. Alternatively, error in measuring brain temperature may have obscured the hypothesised causal relationship between temperature and stress. More research is needed to confirm whether cooling the head is a simple way to manage stress.
8

Characterization of Putative RNA Thermometers Controlling the Production of Shigella dysenteriae Virulence Factors

Soukup, Eric D. 11 May 2016 (has links)
No description available.
9

Regulation of <i>ompA</i> and Its Effect on <i>Shigella</i> Virulence

Dunson, Amanda E. 20 May 2014 (has links)
No description available.
10

Taiwan¡¦s ¡§Swing¡¨ Voters¡GA Case Study of 2008 Presidential Election.

Chang, Pei-Chi 28 March 2011 (has links)
none

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