Transition Transmittance

Using file same principle, a submillimeter fiiick film-like gel was synthesized. The one side of fiie gel film was chemically affixed to a glass plate. Figure 4 shows the transmittance of light wifii varied intensity of incident light at a constant temperature for fiie two kinds of gel prepared with different dye concentrations. When fiie intensity of light was slowly increased, the transmittance decreased discontinuously at a certain intensity. Before and after this transition, transmittance was almost constant. As... 

The sonic tool measures the time taken for a sound wave to pass through the formation. Sound waves travel in high density (i.e. low porosity) formation faster than in low density (high porosity) formation. The porosity can be determined by measuring the transit time for the sound wave to travel between a transmitter and receiver, provided the rock matrix and fluid are known. 

A variation on the transit time method is the frequency-difference or sing-around method. In this technique, pulses are transmitted between two pairs of diagonally mounted transducers. The receipt of a pulse is used to trigger the next pulse. Alternatively this can be done using one pair of transducers where each acts alternately as transmitter and receiver. The frequency of pulses in each loop is given by... 

The phase transition temperatures (lower critical solution temperature, LCST) of the pol5miers were obtained from the change in the transmittance of their aqueous solutions (Figure 1). The aqueous solution of the obtained pol5uner was prepared and its transmittance at 500 nm was monitored with increase in the ambient temperature. Both of poly-NIPA and poly-NEA showed a sudden decrease in the transmittance at 37.5 and 69.2 °C, respectively. The result shown in Figure 1 clearly suggests the thermosensitivity of the pol5mers, and the obtained LCST values are close to those reported for poly-NIPA (34.8 °C) [8] and poly-NEA (72 °C) [9]. 

Complicated processes govern wakefulness, sleep, and the transitions leading to sleep initiation and maintenance. Although the neurophysiology of sleep is complex, certain neurotransmitters promote sleep and wakefulness in different areas of the central nervous system (CNS). Serotonin is thought to control non-REM sleep, whereas cholinergic and adrenergic transmitters mediate REM sleep. Dopamine, norepinephrine, hypocretin, substance P, and histamine all play a role in wakefulness. Perturbations of various neurotransmitters are responsible for some sleep disorders and explain why various treatment modalities are beneficial. 

The importance of peptide transmitters in the modulation of sleep and wakefulness has become apparent in recent years. Previous work had focused on the role of monoamines in the circuitry that regulates the transitions between states of vigilance. Histaminergic neurons in the tuberomammillary nucleus are known to be key players in the activation of subcortical afferents during wakefulness (Wada et al, 1991). Activity of noradrenergic neurons in the locus coeruleus correlates with the state of vigilance (Jones, 1991). The role of serotonergic neurons in rapid eye movement (REM) sleep has also been established (Lydic et al., 1987 Monti Jantos, 1992 Fabre et al., 2000). 

Fluorescence molecules are analogous to roaming molecular spies with radio transmitters, radiating information to the experimenter about the state of affairs on the molecular scale, and informing us where the spies are located and how many there are. A feature unique to FRET is the capability to inform us whenever two or more molecules (usually biological macromolecules) are close to one another on a molecular scale (<80 A), and whether they are moving relative to each other (Section 1.3.1.1). It is even sometimes possible to detect how the D and A transition moments are oriented... 

In Figure 52-30 we plot the function -1 /ln(T) to complete this part of the analysis. We note that there is no minimum to the curve, and the noise from source continually improves as the transmittance decreases in this case the previous, conventional derivations agree with our results, although they do not indicate the V2 factor. Noting the transitions from equation 52-140 to 52-142 (and the corresponding portions of the derivation for absorbance noise and relative absorbance noise), we see that this factor arises from the equal noise contributions of the sample and reference channels therefore we conclude that in this case also, the missing factor is due to the neglect of the reference channel noise contribution. 

A photochemically triggered phase transition is again clearly demonstrated. The apparent increase of the transmittance before its sharp decline is seemingly due to a subtle change in interference of... 

The phase transition was traced by monitoring the transmittance of a 500 nm light beam on a Spectronic 20 spectrophotometer (Baush Lomb). The concentration of the aqueous polymer solution was 5 wt%, and the temperature was raised from 15 to 70°C in 2° increments every 10 min. To observe their pH/temperature dependence, the phase transitions of polymers in citric-phosphate buffer solution versus temperature at two pH values (4.0 and 7.4) were measured. 

BINDING CHANGE MECHANISM TRANSMISSION COEFFICIENT TRANSITION STATE THEORY TRANSMISSION DENSITY TRANSMITTANCE TRANSMITTANCE... 

The fabrication process of vanadium oxide (VO2) has also been studied using RBS/C. Since optieal and electrical properties of VO2 are dramatically changed at 68°C due to phase transition, VO2 is regarded as one of the candidates for thermally activated electronic or optical switching devices for optieal fibers or sensors. To obtain the desired properties, the development of the fabrication process for very thin films, without crystalline defects on various substrates, is required. Single-crystalline VO2 thin films on (0001) plane of a sapphire substrate have been synthesized by a laser ablation method. The quality of VO2 was examined by X-ray diffraction and RBS/C method. The eleetrieal resistanee and the optical transmittance of the VO2 film were measured under inereasing and deereasing temperatures. At a temperature of 68 °C, an abrupt transition of resistanee from metal to... 

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