Mutual Prediction of Retention Times in a Variety of Operating Modes in Temperature Programmed Gas Chromatography

2017 ◽  
Vol 14 (1) ◽  
pp. 591-597
Author(s):  
Xinglong Zhang ◽  
Li Ze ◽  
Zhengchun Yang ◽  
Ruoxin Wu ◽  
Cairong Gong ◽  
...  
Keyword(s):  
Constant Pressure ◽  
The Other ◽  
Flow Mode ◽  
Constant Flow ◽  
Operating Modes ◽  
Prediction Of Retention ◽  
Novel Method ◽  
Temperature Programmed ◽  
Relative Errors ◽  
Prediction Of Retention Times

In this paper, a new concept of calibration hold-up time was defined. On the basis of the concept, a novel method was proposed to predict retention times in temperature programmed (isothermal) under constant flow and constant pressure mode each other, and the method also researched in simultaneous pressure and temperature programmed. The prediction results show that average relative errors are 1.33% (0.64%) in temperature programmed (isothermal) under constant pressure mode by using isothermal dates in constant flow mode, and the other way around, average relative errors are 0.62% (−0.62%). For simultaneous pressure and temperature programmed, retention times were predicted by using isothermal dates in constant flow and constant pressure mode, average relative errors are −0.24% and −0.16%; and retention times were predicted by using isothermal dates directly, average relative errors are −0.62%.

scholarly journals Oroxylin A, but Not Vasopressin, Ameliorates Cardiac Dysfunction of Endotoxemic Rats

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Chin-Hung Liu ◽  
Mei-Fang Chen ◽  
Tzu-Ling Tseng ◽  
Lih-Geeng Chen ◽  
Jon-Son Kuo ◽  
...  
Keyword(s):  
Cardiac Dysfunction ◽  
Constant Pressure ◽  
Myocardial Dysfunction ◽  
Flow Mode ◽  
Constant Flow ◽  
Oroxylin A ◽  
Beneficial Effects ◽  
Isolated Hearts ◽  
Cardiac Functions ◽  
Coronary Endothelium

The mortality in septic patients with myocardial dysfunction is higher than those without it. Beneficial effects of flavonoid oroxylin A (Oro-A) on endotoxemic hearts were evaluated and compared with that of arginine vasopressin (AVP) which is used to reverse hypotension in septic patients. Endotoxemia in rats was induced by one-injection of lipopolysaccharides (LPS, 10 mg/kg, i.p.), and hearts were isolated 5-hrs or 16-hrs later. Isolated hearts with constant-pressure or constant-flow mode were examined by Langendorff technique. Rate and force of contractions of isolated atrial and ventricular strips were examined by tissue myography. Isolated endotoxemic hearts were characterized by decreased or increased coronary flow (CF) in LPS-treated-for-5hr and LPS-treated-for-16-hr groups, respectively, with decreased inotropy in both groups. Oro-A-perfusion ameliorated while AVP-perfusion worsened the decreased CF and inotropy in both preparations. Oro-A and AVP, however, did not affect diminished force or rate of contraction of atrial and ventricular strips of endotoxemic hearts. Oro-A-induced CF increase was not affected following coronary endothelium-denudation with saponin. These results suggest that Oro-A ameliorates LPS-depressed cardiac functions by increasing CF, leading to positive inotropy. In contrast, AVP aggravates cardiac dysfunction by decreasing CF. Oro-A is a potentially useful candidate for treating endotoxemia complicated with myocardial dysfunction.

Analysis for Coupling Relationship of Oil Pocket under Eccentric Load in Hydrostatic Worktable

2012 ◽  
Vol 233 ◽  
pp. 28-34
Author(s):  
Jian Hua Zhao ◽  
Dian Rong Gao
Keyword(s):  
Machine Tools ◽  
Constant Pressure ◽  
Numerical Control ◽  
Flow Mode ◽  
Work Piece ◽  
Constant Flow ◽  
Oil Film ◽  
Coupling Relationship ◽  
Performance Indexes ◽  
Oil Pockets

The oil pocket of the hydrostatic worktable in the modern heavy numerical control (NC) machine tools is designed under the circumstance that the working load acts equally on the oil pockets. But when the work piece is out of the rotary center of the worktable, the working load acts unequally on the oil pockets, and then the performance indexes for the oil pockets, such as acting force, oil film thickness, hydraulic damping, rated flow, are different. Based on the eccentric working load, under the circumstance that the oil pocket provides the fluid oil with constant pressure and constant flow mode, the coupling relationship between the oil pockets is analyzed, and the expression and the relatively bar graphics are presented. To achieve the machining quality and to prevent against the totally worn-out of the machine tools, it is best to adjust one oil pocket in order to keep the oil film of all oil pockets at the same thickness. While one oil pocket is adjusted, the oil pockets are intercoupling, and then the performance indexes change synchronously. According to the characteristics of the oil pocket in the hydrostatic worktable, the expression on the coupling relationship for the oil pocket is derived, then the performance indexes are analyzed qualitatively and the curves are plotted. The proposed research analyzed qualitatively the coupling relationship on the performance indexes for the constant pressure and the constant flow oil pockets separately in the worktable. It can improve the design efficiency and the accuracy with the help of the computer programs, and provides the reference for the practical engineering.

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