Apparent Pressure Dependence of the Reduced Mobility of Potassium Ions in Gases

1972 ◽  
Vol 29 (1) ◽  
pp. 9-12 ◽  
Author(s):  
Ian R. Gatland
Keyword(s):  
Pressure Dependence ◽  
Potassium Ions ◽  
Reduced Mobility

scholarly journals Quantum Phenomena and the Mobility of Potassium Ions in Argon

1974 ◽  
Vol 27 (2) ◽  
pp. 227 ◽  
Author(s):  
RO Watts
Keyword(s):  
Alkali Metal ◽  
Pressure Dependence ◽  
Room Temperature ◽  
Quantum Mechanical ◽  
Alkali Metal Ions ◽  
Potassium Ions ◽  
Zero Field ◽  
Mechanical Methods ◽  
Quantum Phenomena ◽  
Reduced Mobility

Recent work on the mobilities of alkali metal ions in the noble gases has indicated that there is a pressure dependence of the zero-field reduced mobility. The possibility of temporarily bound dimmers being responsible for this pressure dependence is examined here by quantum mechanical methods for the case of potassium ions in argon and it is shown that the conditions needed for a small pressure dependence do exist at room temperature.

scholarly journals Pressure Dependence and End Effects in Precision Ion Mobility Studies

1974 ◽  
Vol 27 (2) ◽  
pp. 211 ◽  
Author(s):  
MT Elford ◽  
HB Milloy
Keyword(s):  
Pressure Dependence ◽  
Zero Field ◽  
Surface Layers ◽  
End Effects ◽  
Pressure Limit ◽  
Fitting Procedure ◽  
Resonant States ◽  
Mobility Studies ◽  
Cluster Ion ◽  
Reduced Mobility

The mobilities of K + ions have been measured by the Bradbury-Nielsen method in He, Ar, H2 and N 2 at 293 K at pressures and E/Nvalues in the range 1�4-190 torr and 1-28 Td respectively. Three drift tubes were used with drift lengths of 3� 395, 9� 076 and 50�00 cm. The anomalous variation of the reduced mobility with E/ N at low values of E/ N reported by Elford (1971) has been shown to be due to the presence of charged surface layers on the first grid of the time-of-flight system. The dependence of the reduced mobility on pressure also reported by Elford has been confirmed, and an explanation of the pressure dependence in He, Ar and H2 is proposed in terms of the formation of ion-atom or ionmolecule complexes in orbiting resonant states. The zero-field reduced mobilities in the zero-pressure limit have been derived by a fitting procedure and found to be 21 �3 � O' 2, 2�64 � O� 02 and 12� 8 � O' 1 cm2 y-1 S-l for He, Ar and H2 respectively. The pressure dependence of the reduced mobility for K + ions in N2 is shown to be of a different form from the other gases investigated and to be due to the formation of the cluster ion K + . N2. The present data are consistent with the equilibrium constant of Beyer and Keller (1971) for the reaction K + + N2 + N2 +� K + . N2 + N2. The zero-field reduced mobility for K+ ions in N2 in the zero-pressure limit has been found to be 2�50�0�02 cm2 Y-1 s-1.

scholarly journals The Effect of Clustering on the Measurement of the Mobility of Potassium Ions in Nitrogen Gas

1972 ◽  
Vol 25 (4) ◽  
pp. 465 ◽  
Author(s):  
EW McDaniel
Keyword(s):  
Room Temperature ◽  
Pressure Effect ◽  
Gas Pressure ◽  
Potassium Ions ◽  
Zero Field ◽  
Nitrogen Gas ◽  
Pressure Calibration ◽  
Reduced Mobility ◽  
Low Pressures ◽  
Source Of Error

McDaniel and Martin (1971) have suggested that the zero-field reduced mobility of (unclustered) K+ ions in nitrogen at room temperature and low pressures (~ 0�1 torr) is accurately enough known to be useful in pressure calibration of drift tubes and other types of apparatus employed in atomic collision experiments, where the uncertainty in the value of the gas pressure frequently represents the largest source of error in the measurements. Elford (1971) has questioned the validity of this suggestion on the grounds that he has observed a very slight, explicit dependence of the reduced mobility of K+ ions on the gas pressure in drift tube experiments with nitrogen and other gases. Although this pressure effect cannot be reconciled with existing mobility theory (McDaniel and Mason 1972), Elford believes the effect to be real and hence maintains that in fact the true mobility of unclustered K+ ions in nitrogen is not accurately known. The purpose of this communication is to point out that Elford's experiments with nitrogen were conducted at pressures sufficiently high that significant clustering of nitrogen molecules with his K+ ions inevitably occurred and that consequently the suggestion of McDaniel and Martin (1971) is not weakened by his findings.

Motility of leukemic lymphocytes

1990 ◽  
Vol 48 (3) ◽  
pp. 368-369
Author(s):  
Manoj Raje ◽  
Karvita B. Ahluwalia
Keyword(s):  
Quantitative Data ◽  
Laser Doppler Velocimetry ◽  
Acute Lymphocytic Leukemia ◽  
Lymphocytic Leukemia ◽  
Cellular Space ◽  
Differentiated Cells ◽  
Poorly Differentiated ◽  
Solid Tissues ◽  
Well Differentiated ◽  
Reduced Mobility

In Acute Lymphocytic Leukemia motility of lymphocytes is associated with dissemination of malignancy and establishment of metastatic foci. Normal and leukemic lymphocytes in circulation reach solid tissues where due to in adequate perfusion some cells get trapped among tissue spaces. Although normal lymphocytes reenter into circulation leukemic lymphocytes are thought to remain entrapped owing to reduced mobility and form secondary metastasis. Cell surface, transmembrane interactions, cytoskeleton and level of cell differentiation are implicated in lymphocyte mobility. An attempt has been made to correlate ultrastructural information with quantitative data obtained by Laser Doppler Velocimetry (LDV). TEM of normal & leukemic lymphocytes revealed heterogeneity in cell populations ranging from well differentiated (Fig. 1) to poorly differentiated cells (Fig. 2). Unlike other cells, surface extensions in differentiated lymphocytes appear to originate by extrusion of large vesicles in to extra cellular space (Fig. 3). This results in persistent unevenness on lymphocyte surface which occurs due to a phenomenon different from that producing surface extensions in other cells.

On the pressure dependence of the thermodynamical scaling exponent γ

Soft Matter ◽  
2020 ◽  
Vol 16 (19) ◽  
pp. 4625-4631 ◽  
Author(s):  
R. Casalini ◽  
T. C. Ransom
Keyword(s):  
Pressure Dependence ◽  
Scaling Exponent ◽  
Scaling Parameter

In materials with a constant scaling parameter γS, the Isomorph γI is found to vary with pressure, demonstrating γS ≠ γI.

PRESSURE DEPENDENCE OF THE SUPERFLUID DENSITY IN 3He-B

1978 ◽  
Vol 39 (C6) ◽  
pp. C6-37-C6-38 ◽  
Author(s):  
C. N. Archie ◽  
T. A. Alvesalo ◽  
J. E. Bethold ◽  
J. D. Reppy ◽  
R. C. Richardson
Keyword(s):  
Pressure Dependence ◽  
Superfluid Density

PRESSURE DEPENDENCE OF PHONON LINESHAPES OF SOLlD DEUTERIUM IN THE ORDERED STATE

1978 ◽  
Vol 39 (C6) ◽  
pp. C6-97-C6-98
Author(s):  
R. Jochemsen ◽  
V. V. Goldman ◽  
Isaac F. Silvera
Keyword(s):  
Pressure Dependence ◽  
Ordered State

GAS PHASE RAMAN SPECTRUM OF TCNQ AND PRESSURE DEPENDENCE OF THE MODES IN CRYSTALS OF TNCQ°

1981 ◽  
Vol 42 (C6) ◽  
pp. C6-323-C6-325
Author(s):  
C. Carlone ◽  
N. K. Hota ◽  
H. J. Stolz ◽  
M. Elbert ◽  
H. Kuzmany ◽  
...  
Keyword(s):  
Raman Spectrum ◽  
Gas Phase ◽  
Pressure Dependence
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