The Effect of Pressure on the Aquation of Chromium(III) Complexes

1971 ◽  
Vol 49 (10) ◽  
pp. 1644-1647 ◽  
Author(s):  
David L. Gay ◽  
Robert Nalepa
Keyword(s):  
Pressure Dependence ◽  
Pressure Range ◽  
Front Side ◽  
Effect Of Pressure ◽  
Side Process

The effect of pressure on the rates of aquation of Cr(NCS)63− and Cr(NH3)2(NCS)4− has been studied over the pressure range 1 to 2043 atm, at 50 ˆC. The activation volumes for these reactions are found to be 16 ± 2 and −2.4 ± 0.8 ml/mol, respectively. The pressure dependence of the activation volumes, (∂ΔV*/∂P)T, are 15 ± 5 and 0 ± 1 ml/katm mol, respectively. These results are consistent with a dissociative interchange (Id) process for the aquation of Cr(NCS)63− and an SN2 front-side process for the aquation of Cr(NH3)2(NCS)4−.

Effect of Pressure on the Rates of Reaction of Radiolysis Intermediates in Liquid n-Hexane

1971 ◽  
Vol 49 (16) ◽  
pp. 2651-2656 ◽  
Author(s):  
Kamal N. Jha ◽  
Gordon R. Freeman
Keyword(s):  
Carbon Tetrachloride ◽  
Hydrogen Atom ◽  
Pressure Dependence ◽  
Diffusion Coefficients ◽  
Effect Of Pressure ◽  
Scavenging Efficiency ◽  
Kinetics Of ◽  
Positive Ion

The yield of hydrogen from pure hexane, G(H2) = 5.3 ± 0.2 was independent of pressure in the range 1 bar to 4.6 kbars. The G values of H2, HD, and D2 obtained from 11 mol% C6D14 in C6H14 were independent of pressure and were respectively, 4.85, 0.34, and 0.11. The electron and hydrogen atom scavenging efficiencies of carbon tetrachloride and hexadiene-1,3, and the hydrogen atom scavenging efficiency of hexene-1 were independent of pressure. The positive ion scavenging efficiencies of benzene and aniline increased with increasing pressure. The volume of activation for the hydrogen atom reaction with n-hexane is essentially the same as that for the reaction with hexene-1. The pressure dependence of the charge scavenging reactions has been interpreted in terms of the kinetics of spur processes. The treatment is consistent with the fact that the efficiency of the electron scavenging reactions is independent of pressure. The increased efficiency of positive ion reaction under pressure implies that the ratio of the diffusion coefficients of the radiolytic positive ion and electron, D+/D−, increases with increasing pressure.

scholarly journals Experimental Observations of the Diffusion Cooling of Electrons in Argon

1975 ◽  
Vol 28 (6) ◽  
pp. 675 ◽  
Author(s):  
T Rhymes ◽  
RW Crompton
Keyword(s):  
Diffusion Coefficient ◽  
Energy Transfer ◽  
Satisfactory Agreement ◽  
Pressure Dependence ◽  
Pressure Range ◽  
Sampling Technique ◽  
Cooling Effect ◽  
Hydrogen Mixtures ◽  
Gas Molecules

The cooling by diffusion of electrons in argon and in argon–hydrogen mixtures has been studied by the Cavalieri density sampling technique. In the case of argon, the measured values of the reduced diffusion coefficient ND varied by more than a factor of two over the pressure range 2–8 kPa. When small quantities of hydrogen were added to the argon, the cooling effect was reduced due to the increased energy transfer between the electrons and gas molecules. For argon, the magnitude and pressure dependence of ND are in satisfactory agreement with the recent calculations by Leemon and Kumar (1975).

scholarly journals Depolarization Ratios of Methane Raman Bands as a Function of Pressure

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1951
Author(s):  
Dmitry Petrov
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
Natural Gas ◽  
Raman Spectra ◽  
Pressure Dependence ◽  
Pressure Range ◽  
Gas Composition ◽  
Depolarization Ratio ◽  
Depolarization Ratios

In this work, we measured the intensities of Q-branches of the ν1, ν2 and ν3 bands in the polarized and depolarized methane Raman spectra in the pressure range of 1–60 atm. It was established that the pressure dependence of depolarization ratios of the ν2 and ν3 bands are negligible. In turn, the depolarization ratio of the ν1 band increases with increasing pressure and reaches approximately 0.0045 at 60 atm. These data are more precise than previously published ones because ν1 band intensities were determined taking into account the contribution of overlapping lines of ν3 band. The presented data will be useful in calculating the methane polarizabilities at high pressure, as well as in calculating methane Raman spectra for measuring the natural gas composition using Raman spectroscopy.

The Hydraulic Conductivity and Volumetric Elastc Modulus of Cells and Isolated Cell Walls of Nitella and Chara spp.: Pressure and Volume Effects

1975 ◽  
Vol 2 (1) ◽  
pp. 1 ◽  
Author(s):  
U Zimmermann ◽  
E Steudle
Keyword(s):  
Cell Wall ◽  
Hydraulic Conductivity ◽  
Pressure Dependence ◽  
Cell Walls ◽  
Pressure Range ◽  
P Value ◽  
Volume Dependence ◽  
Cell Turgor ◽  
Cell Volumes ◽  
Isolated Cell

The hydraulic conductivities (L*p) and the volumetric elastic moduli (e) of N. flexilis, C. intermedia and C. fragilis were determined by means of direct cell turgor measurements. For large cell volumes (V) the function e = f(P), where P = pressure, is a hyperbola. For small cell volumes e is nearly independent of pressure and the absolute e values are smaller than those obtained for larger volumes. This volume dependence of the volumetric elastic modulus was also verified by measurements of the elastic properties of isolated cell walls of N. Jlexilis under conditions where the lengths of the cell wall tubes prepared from each cell were varied. The volume dependence of e, which is unexpected within the framework of Hooke's law, can be explained by assuming that two different intrinsic moduli e*1 and e*2 are applicable to different cell regions with volumes V*1 and V*2. The quantities e*1 and V*1 are related to the cylindrical part, and e*2 and V*2 to the small node or end regions of the internode. With this assumption the overall e is then given by: e = (e*1e*2V)/(e*2V*1 + e*1 V*2) ? e*1e*2 V /(e*2 V + e*1 V*2) . This indicates that for very large cells e has a saturation value equal to e*1, while for smaller volumes the influence of e*2 will become predominant. The value of e*1 was calculated to be about 7.5 x 10*7 Pa* and that of e*2 to be about 10*6 Pa. Since for small cells the overall volumetric elastic modulus e is mainly determined by e*2, the weak pressure dependence of e in such cells reflects a weak pressure dependence of e*2. On the other hand, the strong pressure dependence of e in large cells points to a strong pressure dependence of e*1. The direct determination of the elastic properties of the end regions of the internodes, which was not possible up to the present, is of great importance for growth and growth regulation. The hydraulic conductivity of Nitella and Chara spp. was found to be independent of cell volume, but dependent on the cell turgor pressure. The L*p values were constant at high pressures, but increased on approaching the plasmolytic points. In contrast, the L*p value of the isolated cell wall of N. flexilis was constant over the whole pressure range 0-8 x 10*5 Pa and amounted to (6.9 � 1.3) x 10-*l2 ms-� Pa-�. Since the L*p value in the living N. flexilis cell increased to 4 x 10-*12 ms-� Pa-� at a pressure of 5 x 10*4 Pa it can be concluded that the cell wall becomes the rate-limiting barrier for water flow and that the hydraulic conductivity of the cell membranes must be remarkable at low pressures. The increase in L, in the low pressure range is not caused by artificial leakages or by leakages through the plasmodesmata, since no water flow across plasmodesmata could be detected.

Effect of Pressure and Shear on Compaction of Powdered Rubber with Carbon Black

1985 ◽  
Vol 58 (2) ◽  
pp. 392-406
Author(s):  
N. Nakajima ◽  
P. R. Kumler ◽  
E. R. Harrell
Keyword(s):  
Carbon Black ◽  
Pressure Range ◽  
Static Pressure ◽  
Lower Pressure ◽  
Bridge Structure ◽  
Capillary Rheometer ◽  
Solid Mass ◽  
Effect Of Pressure ◽  
Rotor Surface ◽  
Powdered Rubber

Abstract During the incorporation stage of mixing carbon black with elastomer, the mixture becomes one solid mass, i.e., compacted. In this process, the elastomer must be deformed to conform with the topology of carbon black. This work attempts to elucidate the mechanism of compaction. In particular, the effects of static pressure and shear on compaction have been examined. A Sieglaff-McKelvey capillary rheometer was used for the higher pressure range and a Rheometrics mechanical spectrometer for the lower pressure range. A mixture of powdered rubber and carbon black was used. With static pressure alone, the compaction was slow and ineffective because the mixture forms a bridge structure. The compacted material was friable. With the application of shear, the bridge structure was easily broken, the compaction was attained immediately, and the compacted material was “fused” together. However, the application of shear was effective only when there was no slip between the rotor surface and the elastomer compound.

The Effect of Pressure on the Critical Temperature of Four-Component Microemulsioms

1989 ◽  
Vol 177 ◽  
Author(s):  
Jacques Goyette ◽  
T. K. Bose ◽  
J. Thoen ◽  
J. R. Lalanne
Keyword(s):  
Refractive Index ◽  
Critical Temperature ◽  
Correlation Length ◽  
Critical Points ◽  
Pressure Dependence ◽  
Sodium Dodecylsulfate ◽  
Nonlinear Behavior ◽  
Negative Sign ◽  
Effect Of Pressure ◽  
Line Ending

ABSTRACTWe present results for the pressure dependence of the critical temperature (dTc/dP) for several microemulsions of n-dodecane, water, n-pentanol and sodium dodecylsulfate with critical points along a criticial line ending at a critical end point (CEP). The variation of dTc/dP as a function of the water to surfactant ratio X shows a nonlinear behavior, with large changes near the CEP, and similar to the X dependence previously observed for the correlation length amplitude ξo. From the negative sign of dTc/dP we also conclude that a possible anomaly in the density must be opposite to the anomaly recently reported for the refractive index.

Through Wafer Interconnects - A Technology not only for Medical Applications

2006 ◽  
Vol 969 ◽  
Author(s):  
Gereon Vogtmeier ◽  
Christian Drabe ◽  
Ralf Dorscheid ◽  
Roger Steadman ◽  
Dr. Alexander Wolter
Keyword(s):  
Cmos Process ◽  
Back Side ◽  
Front Side ◽  
Process Flow ◽  
Poly Silicon ◽  
Side Process ◽  
Cmos Compatible ◽  
Photodiode Arrays ◽  
Wafer Thinning ◽  
Application Specific

AbstractThe foremost driver for the development of fully CMOS compatible Through Wafer Interconnects (TWIs) is the need of very large photodiode arrays for detectors, e.g. in computed tomography applications. The front to back-side contact allows the four-side buttable chip placement of the already large chips (20mm × 22mm2). The TWI technology allows an interconnection for chips up to 280μm thickness. This technique does not require any via opening at the font side, thus enabling a metal signal routing on the active side, on top of the interconnection. The application specific optical sensitive front-side of the chip is fully accessible. The production process is separated into three main steps. The first step is the implementation of the special TWI geometry into the CMOS substrate. Depending on the electrical and geometrical requirements of the circuit, different TWI structures are built with deep trenches (up to 280μm), which are passivated and filled with doped poly-silicon. The technologies used in this process, such as DRIE-etching, oxidation and low pressure CVD, are standard CMOS compatible processes. The use of poly-silicon prevents from achieving very low resistivity interconnections but allows the use of all CMOS process steps for an imager production (no temperature limitation – compared to other TWI process flows). The second step is the standard CMOS processing on the substrate already including the TWIs. The third step is a low temperature back-side process starting with wafer thinning down to 280μm or less to open the implemented TWI structure from the back-side. The thickness may be selected depending on the target application. A modified under ball metallization (UBM) process, which could include also re-routing of signals on the back-side, concludes the process flow until the solder ball placement, or similar bond connections.The special process flow opens a variety of applications which benefit from the full CMOS compatible processing and the accessible front-side.

Pressure dependence of the superconductor transition temperature ofCa(Fe1−xCox)AsFcompounds: A comparison with the effect of pressure onLaFeAsO1−xFx

2010 ◽  
Vol 81 (5) ◽  
Author(s):  
Hironari Okada ◽  
Hiroyuki Takahashi ◽  
Satoru Matsuishi ◽  
Masahiro Hirano ◽  
Hideo Hosono ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Pressure Dependence ◽  
Effect Of Pressure

scholarly journals Thermalization in Infrared Multiple Photon Induced Reactions. The Pressure Dependence of the Trans → Cis Isomerization of Crotonitrile

1990 ◽  
Vol 10 (4) ◽  
pp. 227-238 ◽  
Author(s):  
Joseph R. Guckert ◽  
Robert W. Carr
Keyword(s):  
Laser Radiation ◽  
Pressure Dependence ◽  
Pressure Range ◽  
Laser Pulses ◽  
Low Pressure ◽  
Trans Form ◽  
Collisional Regime

The infrared multiple photon trans → cis isomerization of crotonitrile was studied over the pressure range 0.02 torr to 10 torr at fluences of approximately 4J/cm2 using collimated TEA CO2 laser radiation at 942 cm-1. Only minor quantifies of fragmentation products were found at these conditions. At pressures of 0.1 torr or less, the trans form was completely converted to cis form by about 5000 laser pulses. On increasing the pressure a collisional regime was entered in which photostationary states were reached with fewer pulses and having smaller conversions than at low pressure. Both the number of pulses and the conversion decreased monotonically with increasing pressure. The tactic of driving the reaction in the exothermic direction gave evidence that the reaction does not occur solely by thermal isomedzation even in the highly eollisional 10 torr experiments, but that it still has a nonthermal component due to laser induced isomerization.

Pressure Dependence of the Thermodynamic Quantities in Phase II of Solid Benzene

2013 ◽  
Vol 32 (5) ◽  
pp. 421-425 ◽  
Author(s):  
H. Yurtseven ◽  
E. Sevinc
Keyword(s):  
Phase Ii ◽  
Pressure Dependence ◽  
Isothermal Compressibility ◽  
Molecular Crystal ◽  
Pressure Range ◽  
High Pressures ◽  
Solid Phase ◽  
Experimental Measurements ◽  
Thermodynamic Quantities ◽  
Volume Data

AbstractThe thermodynamic quantities such as the thermal expansion (αp), isothermal compressibility (KT) and the specific heat (CP − CV), are predicted at various pressures up to 26 GPa (T = 540 K) in the solid phase II of benzene using volume data from the literature. The Pippard relations are examined using the pressure dependence of αp, KT and CP − CV and the value of the slope dP/dT is deduced for the solid phase II of benzene. The thermodynamic quantities studied here decrease with increasing pressure, as expected, which can be compared with the experimental measurements for the solid phase II of benzene. We find that the Pippard relations are validated within the pressure range considered, in particular, at high pressures for the solid phase II of this molecular crystal.

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