Spectroscopic studies of impurity-host interactions in dye-doped polymers: Hydrostatic-pressure effects versus temperature effects

1987 ◽  
Vol 36 (14) ◽  
pp. 7601-7611 ◽  
Author(s):  
Th. Sesselmann ◽  
W. Richter ◽  
D. Haarer ◽  
H. Morawitz
Keyword(s):  
Hydrostatic Pressure ◽  
Temperature Effects ◽  
Spectroscopic Studies ◽  
Pressure Effects ◽  
Host Interactions ◽  
Doped Polymers

Hydrostatic Pressure—Temperature effects on Deep-sea Colonisation

1972 ◽  
Vol 73 ◽  
pp. 195-202 ◽  
Author(s):  
Robert J. Menzies ◽  
Robert Y. George
Keyword(s):  
Hydrostatic Pressure ◽  
Deep Sea ◽  
Temperature Effects ◽  
Marine Species ◽  
Pressure Effects ◽  
Pressure Sensitivity ◽  
Temperature And Pressure ◽  
Pressure Resistance ◽  
Increased Activity ◽  
Temperature And Pressure Effects

SynopsisA diverse benthic and bathypelagic fauna was first incontrovertably established by the deep-sea samples of H.M.S.Challenger, and demonstrated the ability of organisms to live and reproduce in the deep, dark and cold abyssal environment of enormous hydrostatic pressure as high as 1000 atm (14 000 psi) on trench floors at 10 000 metres. The investigations of Regnard (1891), Fontaine (1930) and Ebbecke (1935) established that various shallow animals have the capacity to withstand increased hydrostatic pressure. This paper deals with the response of whole organisms, mainly shallow-water metazoans, to hydrostatic pressure-temperature effects. The level of occurrence of pressure-induced increased activity (R1), onset of paralysis or tetany (T) and LD50are discussed for tropical and temperate marine species in relationship to temperature and hydrostatic pressure. The pressure sensitivity and resistance exhibited by different species are examined in relation to various hypotheses and theories such as (1) group effect, in which Schlieper (1968) claims that those shallow species that belong to the group which has successfully colonised the deep sea, such as Echinodermata, Mollusca, Isopoda, have a higher pressure resistance; (2) pressure resistance as a species or genetic property; (3) environmental impact, in which deeper species have a greater pressure resistance; and (4) finally a re-examination of temperature and pressure effects as these relate to deep-sea colonisation.

Optical Spectroscopic Studies of a Soluble Fluorene-Based Conjugated Polymer: A Hydrostatic Pressure and Temperature Study

2001 ◽  
Vol 708 ◽  
Author(s):  
S. Guha ◽  
J.D. Rice ◽  
C. M. Martin ◽  
W. Graupner ◽  
M. Chandrasekhar ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Conjugated Polymer ◽  
Spectroscopic Properties ◽  
Spectroscopic Studies ◽  
Phonon Interaction ◽  
Optical Studies ◽  
Strong Electron ◽  
Conjugated Molecules ◽  
Electron Phonon Interaction ◽  
Backbone Conformation

ABSTRACTSpectroscopic properties of conjugated molecules/polymers have varying degrees of sensitivity to backbone conformation. Optical studies are presented as a function of temperature and hydrostatic pressure, using photoluminescence and Raman scattering from two polymers with distinct differences in their backbone conformation, namely, polyfluorene (PF) and ladder type poly(para-phenylene)(m-LPPP). In contrast to the photoluminescence (PL) vibronics in mLPPP, the 0-0 PL vibronic peak in PF shows a red-shift with increasing temperatures. Pressure studies reveal that the PL spectrum of PF red-shifts and broadens with increasing pressures. The phonon lines in PF show an antiresonance effect at higher pressures indicating a strong electron-phonon interaction.

Hydrostatic pressure effects on vestibular hair cell afferents in fish and crustacea

2003 ◽  
Vol 13 (4-6) ◽  
pp. 235-242
Author(s):  
Peter J. Fraser ◽  
Stuart F. Cruickshank ◽  
Richard L. Shelmerdine
Keyword(s):  
Hydrostatic Pressure ◽  
Hair Cells ◽  
Signal To Noise Ratio ◽  
Angular Acceleration ◽  
Pressure Effects ◽  
Sensory Cells ◽  
Associated Gas ◽  
Piston Mechanism ◽  
New Finding ◽  
Resting Activity

Following the discovery of a hydrostatic pressure sensor with no associated gas phase in the crab, and the knowledge that several systems of cells in culture show long term alterations to small changes in hydrostatic pressure, we show here that vestibular type II hair cells in a well known model system (the isolated elasmobranch labyrinth), are sensitive to hydrostatic pressure. This new finding for the vertebrate vestibular system may provide an explanation for low levels of resting activity in vertebrate hair cells and explain how fish without swim bladders sense hydrostatic cues. It could have implications for humans using their balancing systems in hypobaric or hyperbaric environments such as in aircraft or during space exploration. Although lacking the piston mechanism thought to operate in crab thread hairs which sense angular acceleration and hydrostatic pressure, the vertebrate system may use larger numbers of sensory cells with resultant improvement in signal to noise ratio. The main properties of the crab hydrostatic pressure sensing system are briefly reviewed and new experimental work on the isolated elasmobranch labyrinth is presented.

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