INDEX temperature effects

All oils become thinner when heated and thicker when cooled, but some are less sensitive than others to these viscosity/temperature effects. The degree of sensitivity is known as Viscosity Index (VI). Oil is said to have high VI if it displays a relatively small change of viscosity for a given change of temperature. 

Experimental conversion-time data, obtained from the literature, on the bulk free radical polymerization of MMA initiated by AIBN at several temperatures and initiator concentrations, were described by the model. However, the expressions for the rate of conversion and gel effect index were first simplified and rearranged. ... 

Color Index Name Temperature effect in CIELAB units Fastness to overpainting on a fastness scale from 1 to 5 Bleed resistance on a fastness scale from 1 to 5... 

The major advantage of this detector is that it is almost universal. All substances have their own characteristic refractive index (it is a physical property of the substance). Thus, the only time that a mixture component would not give a peak is when it has a refractive index equal to that of the mobile phase, a rare occurrence. The disadvantages are that it is not very sensitive and the output to the recorder is subject to temperature effects. Also, it is difficult to use this detector with the gradient elution method because it is sensitive to changes in the mobile phase composition. 

A common cause of baseline drift is a slow elution of substances previously adsorbed on the column. A column cleanup procedure may be in order, or it may need to be replaced. This problem may also be caused by temperature effects in the detector. Refractive index detectors are especially vulnerable to this. In addition, a contaminated detector can cause drift. The solution here may be to disassemble and clean the detector. 

Just like refractive index, the °Brix scale is quite dependent on the temperature. Manual Abbe refractometers do not compensate for this temperature effect. Special correlation tables are used to adjust the readings to a standard temperature, 20°C. Digital refractometers, on the other hand, can operate over a fairly wide range of sample temperatures (+15 to +40°C) and automatically apply these temperature corrections. See Workplace Scene 15.2. 

Slow elution of chemicals adsorbed on the column, 2) temperature effects, such as with the refractive index detector, and 3) a contaminated detector... 

Attention should be paid to possible problems in the measurement of fluorescence quantum yields (some of which are discussed Section 6.1.5) inner filter effects, possible wavelength effects on Op, refractive index corrections, polarization effects, temperature effects, impurity effects, photochemical instability and Raman scattering. 

A 25 cm X 4.6 mm ID long 300A SynChropak column was used to evaluate temperature effects. Injections were made with 5% D2O and 1.3 mg/ml glucose solutions. D2O gave a negative refractive index response. 

Day AG. Oxygen index test Temperature effect and comparison with other flammability tests. Plast. Polym. 1975 43 64-67. 

Thermal Alteration Index. This index, of a very empiric nature, tries to define the maximum temperature reached by the rock in terms of color and preservation of the sample (for more details see e.g. Correia (34)). The use of this index has been very useful in studies with the Irati F. to detect temperature effects due to the diabase intrusion. Used as a stratigraphic function in the column CERI-1 it was possible to detect a heat effect on the top of the lower... 

An application of continuum solvation calculations that has not been extensively studied is the effect of temperature. A straightforward way to determine the solvation free energy at different temperatures is to use the known temperature dependence of the solvent properties (dielectric constant, ionization potential, refractive index, and density of the solvent) and do an ab initio solvation calculation at each temperature. Elcock and McCammon (1997) studied the solvation of amino acids in water from 5 to 100°C and found that the scale factor a should increase with temperature to describe correctly the temperature dependence of the solvation free energy. Tawa and Pratt (1995) examined the equilibrium ionization of liquid water and drew similar conclusions. An alternative way to study temperature effect is through the enthalpy of solvation. The temperature dependence of is related to the partial molar excess enthalpy at infinite dilution,... 

Base stock specifications, as defined by the producer or the purchaser, largely enumerate the physical properties required for the fluid—typically density, viscosity at two temperatures, viscosity index (VI), low temperature performance measures, flash and volatility properties, and solubility information from aniline point or viscosity-gravity constant (VGC)—the latter two are usually for naphthenic base stocks. While chemical composition is responsible for physical properties, it usually only surfaces as measurements of heteroatom content—sulfur and nitrogen—and aromatics content (or conversely that of saturates). Sulfur and aromatics levels in paraffinic base stocks are now criteria for American Petroleum Institute (API) classifications. However, detailed chemical compositional information is needed to understand the chemistry of the unit processes, the effects of changes in feeds, catalysts, and operating conditions, and behaviors of finished lubricant products. 

TEMPERATURE, EFFECTIVE - An arbitrary index which combines into a single value the effect of temperature, humidity, and air movement on the sensation of warmth or cold felt by the human body. The numerical value is that of the temperature of still, saturated air which would induce an identical sensation. 

Temperature Humidity Index - An index that combines sensible temperature and air humidity to arrive at a number that closely responds to the effective temperature used to relate temperature and humidity to levels of comfort. 

Refractometry Refractometry is a quick and reasonably accurate alternative to chemical analysis for serum total protein when a rapid estimate is required. The refractive index of water at 20°C is 1.330 if solute is added to the water, the refractive index of a dilute solution increases linearly and proportionally to the solute concentration at higher concentrations of dissolved solids (50-200gl ), the increase is nearly linear. Temperature affects appreciably the refractive index of a solution, so refracto-meters for clinical use compensate for temperature effects. Serum contains dissolved solids in concentrations of 80-100 gl, most of which are proteins. In the refractometry of serum, it is assumed that the concentration of inorganic electrolytes and nonprotein organic compounds does not vary appreciably from serum to serum and that the differences in the refractive index reflect primarily the differences in protein concentrations. The assumption has been shown to be reliable for clear, nonpigmented samples, but hemolysis, lipemia, icterus, and azotemia produce erroneously high results. The method cannot be used for urine protein measurement because of excess solutes in relation to the protein. 

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