Ambient pressure dependence of the ultra-harmonic response from contrast microbubbles

The cubic Laves phase compound YMn2 exhibits a huge spontaneous volume magnetostriction at the Néel temperature (TN=100 K). The magnetic moment per Mn atom is 2.7 μB at 2 K. From polarized neutron diffraction in the paramagnetic state it has been shown that the effective moment persisting above TN is reduced (1.6 μB at 120 K). The anomalously large pressure dependence of TN (dTN/dp=–35 K/kbar) is an evidence for the sensitive role played by the Mn—Mn interatomic distances. In the paramagnetic state, the influence of spin fluctuations dominates the physical properties. We have studied the effect of pressure on the resistivity up to 16 kbar. From dρ/dT we have estimated the spinfluctuation temperature as a function of pressure. The value at ambient pressure is 15 K which is in agreement with that determined in the paramagnetic Y0.9Lu0.1Mn2 compound.

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Pressure dependence of the deuterium isotope effect in the photolysis of formaldehyde by ultraviolet light

Atmospheric Chemistry and Physics ◽

10.5194/acp-10-3455-2010 ◽

2010 ◽

Vol 10 (7) ◽

pp. 3455-3462 ◽

Cited By ~ 17

Author(s):

E. J. K. Nilsson ◽

V. F. Andersen ◽

H. Skov ◽

M. S. Johnson

Keyword(s):

Isotope Effect ◽

Pressure Dependence ◽

Kinetic Isotope Effect ◽

Ambient Pressure ◽

Deuterium Isotope Effect ◽

Kinetic Isotope ◽

Molecular Channel ◽

The University ◽

First Time ◽

Gas Pressures

Abstract. The pressure dependence of the relative photolysis rate of HCHO vs. HCDO has been investigated for the first time, using a photochemical reactor at the University of Copenhagen. The dissociation of HCHO vs. HCDO using a UVA lamp was measured at total bath gas pressures of 50, 200, 400, 600 and 1030 mbar. The products of formaldehyde photodissociation are either H2 + CO (molecular channel) or HCO + H (radical channel), and a photolysis lamp was chosen to emit light at wavelengths that greatly favor the molecular channel. The isotope effect in the dissociation, kHCHO/kHCDO, was found to depend strongly on pressure, varying from 1.1 + 0.15/−0.1 at 50 mbar to 1.75±0.10 at 1030 mbar. The results can be corrected for radical channel contribution to yield the kinetic isotope effect for the molecular channel; i.e. the KIE in the production of molecular hydrogen. This is done and the results at 1030 mbar are discussed in relation to previous studies at ambient pressure. In the atmosphere the relative importance of the two product channels changes with altitude as a result of changes in pressure and actinic flux. The study demonstrates that the δD of photochemical hydrogen produced from formaldehyde will increase substantially as pressure decreases.

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Study on the Pressure Dependence of Boiling Point, Flashpoint, and Lower Flammability Limit at Low Ambient Pressure

Industrial & Engineering Chemistry Research ◽

10.1021/ie503383a ◽

2015 ◽

Vol 54 (6) ◽

pp. 1899-1907 ◽

Cited By ~ 9

Author(s):

Chao Ding ◽

Yaping He ◽

Jiusheng Yin ◽

Wei Yao ◽

Dechuang Zhou ◽

...

Keyword(s):

Pressure Dependence ◽

Boiling Point ◽

Ambient Pressure ◽

Flammability Limit ◽

Lower Flammability Limit

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Enhanced ambient pressure sensitivity of the subharmonic signal from ultrasound contrast microbubbles

2013 IEEE International Ultrasonics Symposium (IUS) ◽

10.1109/ultsym.2013.0084 ◽

2013 ◽

Author(s):

Fei Li ◽

Feiyan Cai ◽

Long Meng ◽

Qiaofeng Jin ◽

Hairong Zhen ◽

...

Keyword(s):

Ambient Pressure ◽

Pressure Sensitivity ◽

Ultrasound Contrast ◽

Contrast Microbubbles

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Oxygen Pressure Dependence of Morphology of Morphology of La2-xSrxCuO4 Ultra-Thin Films

Modern Physics Letters B ◽

10.1142/s0217984997001195 ◽

1997 ◽

Vol 11 (21n22) ◽

pp. 981-987

Author(s):

H. Q. Yin ◽

T. Arakawa ◽

Y. Kaneda ◽

T. Yoshikawa ◽

N. Haneji ◽

...

Keyword(s):

Thin Films ◽

Pressure Dependence ◽

Film Growth ◽

Ambient Pressure ◽

High Energy ◽

Layer Growth ◽

Growth Mode ◽

Layer By Layer ◽

Island Growth ◽

Experimental Conditions

La 2-x Sr x CuO 4 ultra-thin films with thickness 200 Å were fabricated by pulsed laser deposition method in oxygen ( O 2) atmosphere. The morphology of deposited films was investigated by reflection high energy electron diffraction (RHEED), atomic force microscopy (AFM) and scanning electronic microscopy (SEM). The strong oxygen ambient pressure dependence of film morphology was observed. In high oxygen ambient pressure, the film growth is dominated by island growth mode. The results imply that the experimental conditions of oxygen ambient pressure and substrate temperature are critical for the layer-by-layer growth mode.

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CORRELATION OF TRANSPORT AND TOPOLOGICAL/SPIN DISORDER FOR SOME AMORPHOUS METALLIC AND MAGNETIC ALLOYS

International Journal of Modern Physics B ◽

10.1142/s0217979293002109 ◽

1993 ◽

Vol 07 (01n03) ◽

pp. 968-971

Author(s):

K. BÄRNER ◽

J.-W. SCHÜNEMANN ◽

K. HEINEMANN ◽

A.A. GANIN ◽

Yu.S. BERSENEV ◽

...

Keyword(s):

Curie Temperature ◽

Pressure Dependence ◽

Minimum Temperature ◽

Ambient Pressure ◽

Magnetic Alloys ◽

Pressure Derivative ◽

Spin Disorder ◽

Magnetic Disorder ◽

Resistivity Minimum

The resistivity ρ and the permeability μ of amorphous magnetic ribbons (Fe100−xMnx)75P15C10 are determined at ambient pressure and pressures up to 15 kbar and correlated with the topological and magnetic disorder. The characterization includes the Curie temperature Tc, its pressure derivative ∂Tc/∂p and the pressure dependence of the resistivity minimum temperature.

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Evolution of Superconducting and Hidden Order Phases in URu2Si2 Under Applied Pressure

MRS Proceedings ◽

10.1557/proc-1104-nn09-02 ◽

2008 ◽

Vol 1104 ◽

Author(s):

M. Brian Maple ◽

Jason R. Jeffries ◽

Nicholas P. Butch ◽

Benjamin T. Yukich

Keyword(s):

Critical Field ◽

Pressure Dependence ◽

Ambient Pressure ◽

Applied Pressure ◽

Upper Critical Field ◽

Qualitative Change ◽

Resistivity Measurements ◽

Surface Fraction ◽

Hidden Order ◽

Two Phases

AbstractElectrical resistivity measurements performed under applied hydrostatic pressure and in magnetic fields have been used to probe the hidden order (HO) and superconducting (SC) states of URu2Si2, which have ambient-pressure transition temperatures TO = 17.5 K and Tc = 1.5 K, respectively. TO increases with applied pressure and a distinct kink in its pressure dependence is observed at 15 kbar; this feature is associated with the onset of antiferromagnetism. The pressure dependence of the SC upper critical field has been measured with the external field aligned parallel to both crystalline axes. The SC phase is smoothly suppressed to a critical pressure of about 15 kbar and no qualitative change in the critical field curves is observed. The co-evolution of the HO and SC phases is discussed within the context of a model in which the two phases compete for Fermi surface fraction.

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