Temperature quality factor

The part stress analysis prediction section contains failure rate models for a broad variety of parts used in electronic equipment. This method includes the effects of part quality factors and environmental factors. The tabulated values of the base failure rate are "cut off" at the design temperature and stress of the part. 

So in order to minimize this noise one possibility is to work at low temperature, this is what is done in the Japanese TAMA project. The other solution is to use optical materials with a low value of the loss angle, or equivalently a high quality factor. 

IP-2.2.7(d). The strength reduction factor represents the reduction in yield strength with long-term exposure of the material to elevated temperatures and, in the absence of more applicable data, shall be taken as 1.0 for austenitic stainless steel and 0.8 for other materials. For castings, the basic allowable stress shall be multiplied by the casting quality factor, Ec. Where the allowable stress value exceeds two-thirds of yield strength at temperature, the allowable stress value must be reduced as specified in para. IP-2.2.7(c). Wind and earthquake forces need not be considered as acting concurrently. At temperatures warmer than 427°C (800°F), use 1.33... 

Here, ks is the Boltzmann constant (1.38 x 10-23 J/K), T is the absolute temperature (300 K at room temperature), B is the bandwidth of measurement [typically about 1000 Hz for direct current (dc) measurement], /o is the resonant frequency of the cantilever, and Q is the quality factor of the resonance, which is related to damping. It is clear from Eq. (12.8) that lower spring constant, K, produces higher thermal noise. This thermal motion can be used as an excitation technique for resonance frequency mode of operation. 

A simple method for determining the temperature inside the sample volume of an NMR probe is the quantitative evaluation of the absolute intensity using Curie s law (Eq. (25)). However, this approach is limited to systems that heat the sample volume only and not the radio frequency coil or other electronic parts of the probe. A heating of the radio frequency coil strongly influences the quality factor of the NMR probe and leads to an additional change of the signal intensity and, therefore, renders the quantification of intensity more complicated. 

Loeffler, H. J. Processing of orange juice effect of storage temperature on quality factors of bottled juice. 

This relaxation time—which, to be specific, we have written in the Landau-Lifshitz representation—has the anticipated behavior the smaller the precession damping constant (the higher the quality factor of the oscillations), the slower does the particle magnetic moment approach its equilibrium position. For ferromagnet or ferrite nanoparticles the typical values of the material parameters are Is Is < 103G, Vm 10 18cm3, and a 0.1. Substituting them in formula (4.28) aty 2 x 108 rad/Oe s and room temperature, one obtains xD 10-9 s. 

Some compounds, however, display no resonance at this temperature, e. g. ICN 10) and piperazine 12) in the former compound, strains may explain the absence of the lines observed at higher temperatures. Operation at liquid nitrogen temperature is convenient because it enhances the Boltzmann factor and the tank coil quality factor. On the other hand, long relaxation times may reduce line intensities below observability, so that it may be better to operate at a slightly higher temperature where relaxation times are shorter while the Boltzmann factor and the coil quality are not much decreased13). 

With the progress in microwave telecommunication technology, dielectric materials have come to play an important role in the miniaturization and compactness of microwave passive components. The dielectric materials available for micro-wave devices are required to have predictable properties with respect to a high dielectric constant (K), high quality factor (Qf), and small temperature coefficient of resonant frequency (TCP). Numerous microwave dielectric materials have been prepared and investigated for their microwave dielectric properties and for satisfying these requirements. In particular, complex perovskite compounds A(B,B )03... 

The interaction of water, temperature and seed quality factors on seed aging kinetics can be examined through a simple model that describes kinetics of... 

Tests are conducted to determine capacity, heat transfer rates, steam economy, product losses, and cleaning cycles. Practically all the criteria of evaporator performance are obtained from differences between test measurements. Errors can result when measuring flow rates, temperatures and pressures, concentrations, and steam quality. Factors which can have a great effect on performance include dilution, vent losses, heat losses, and physical properties of fluids. 

Performance and Diode Parameters. For finding the optimum absorber composition, organic solar cells of the type A with various [CuPc] [C60] ratios were prepared at a non-optimised substrate temperature. The Eff behaviour with the absorber composition (Fig. la) is dominated by the behaviour of the Jso and FF [4], In the compositional range investigated, 0.2 < [CuPc]/([CuPc] + [C60]) < 0.8, the devices V00 is almost constant taking values of about 400 mV (not shown). An efficiency of 1.6% is achieved in Fig. la at a [CuPc] [C60] composition of about 1 1 (by weight) [4], The diode quality factor, n. of the devices decreases from 2.6-2.7 at the either minimum of CuPc or C6o content to 1.8 at 1 1 absorber composition. At the same time, the OSCs series resistance decreases almost symmetrically from 0.34-0.38 Q x cm2 at a content of 17% of either CuPc or C to -0.2 Q x cm2 at an identical content of CuPc and C6o-... 

Fig. 2. (a) Diode quality factor and (b) series resistance of the ITO/PEDOT PSS/ CuPc C60/ Mg/Ag OSCs as a function of preparation temperature. The doted lines are guides to the eye. 

The diode quality factor n of type A devices decreases as a function of substrate temperature in Figure 2a from 2.4-2.6 at Tsubstrate = 131°C or Tsubstrate = 187°C to 1.5 at Tsubstrate = 151°C. The behavior of the series resistance (Rs) with temperature is shown in Fig. 2b. The minimum Rs = 0.27 Q x cm2 is achieved for type B OSCs at Tsubstrate = 148°C. The enhancement of the devices PV and diode parameters with the temperature up to 150°C can be explained by (i) an improved separation of the CuPc and Cm donor and acceptor materials in an interpenetrated absorber network, (ii) enhanced crystalline perfection of the CuPc domains [4] and therefore improved transport properties, i.e., better collection efficiency of photogenerated carriers at the respective electrode. Alteration of the photoelectrical parameters at higher temperatures can be attributed to the potential degradation of the PEDOT buffer layer. 

The solvent relaxes not with the expected Ti time constant (i.e. small rate constant), but instead with a much smaller observed time constant Tird that is proportional to the quality factor (Q), filing factor (77, ratio of sample volume over coil volume), ° and the magnetization (equilibrium being Mq). Room temperature probes typically have a Q of perhaps a few hundred units but cryogenically cooled probes can push this value to 1500 (or even upwards of 40 000 is possible though not applied in biomolecular probes). The increased rate of relaxation due to radiation dampening is immediately evident. 

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