Methylene unit calibration for analysis of organic acids by gas--liquid chromatography/mass spectrometry.

1982 ◽  
Vol 28 (2) ◽  
pp. 349-351
Author(s):  
I L Bromberg ◽  
J A Heininger ◽  
A G Cherian
Keyword(s):  
Reference Standards ◽  
Gas Liquid Chromatography ◽  
Good Precision ◽  
Exponential Relationship ◽  
Long Term Stability ◽  
Methylene Unit ◽  
Mass Spectrometer System ◽  
Computer Controlled ◽  
Spectrometer System

Abstract We describe a method for automatic computation of "methylene unit" retention-time indices in real time on a computer-controlled gas chromatograph/mass spectrometer system. The calculation is based on the exponential relationship between the methylene unit values of hydrocarbon reference standards and the oven temperature at their elution. Using this mathematical relationship, we calculated calibration factors, which eliminates the need to include a set of methylene unit reference standards with each run and simplifies and speeds identification of unknown peaks in chromatograms. Long-term stability and good precision of the calibration factors were observed during the six-month period of study.

The Selection and Application of Filling Material Based on Long-Term Strength of Backfill Body

2011 ◽  
Vol 239-242 ◽  
pp. 3156-3160
Author(s):  
Bao Jie Fu ◽  
Min Tu
Keyword(s):  
High Stress ◽  
Filling Material ◽  
Term Strength ◽  
Exponential Relationship ◽  
Rock Body ◽  
Deep Mine ◽  
Long Term Stability ◽  
Working Face ◽  
Support Resistance

High stress makes backfill body present the rheological properties in deep mine. This paper first uses RRTS-ⅢA to carry on creep test of specimen in different proportion, according to ε-t curves under different load levels to determine the specimen’s long-term strength, based on the exponential relationship of rock block and rock body, the long-term compressive strength is derived, combining with concrete parameters of working face, mixture ratios of filling material which meet long-term stability are selected, while analyzing the support resistance of backfill body. The results show that this design can effectively avoid the rheological instability of backfill body.

Development of a totally computer‐controlled triple quadrupole mass spectrometer system

1983 ◽  
Vol 54 (8) ◽  
pp. 996-1004 ◽  
Author(s):  
Carla M. Wong ◽  
Richard W. Crawford ◽  
Victor C. Barton ◽  
Hal R. Brand ◽  
Kenneth W. Neufeld ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Quadrupole Mass Spectrometer ◽  
Triple Quadrupole ◽  
Quadrupole Mass ◽  
Triple Quadrupole Mass Spectrometer ◽  
Mass Spectrometer System ◽  
Computer Controlled ◽  
Spectrometer System

Stability and Change in Emotional Intelligence: Exploring the Transition to Young Adulthood

2005 ◽  
Vol 26 (2) ◽  
pp. 100-106 ◽  
Author(s):  
James D.A. Parker ◽  
Donald H. Saklofske ◽  
Laura M. Wood ◽  
Jennifer M. Eastabrook ◽  
Robyn N. Taylor
Keyword(s):  
High School ◽  
Emotional Intelligence ◽  
Postsecondary Education ◽  
Life Transition ◽  
Full Time ◽  
Major Life ◽  
Long Term Stability ◽  
Time Period ◽  
Transition From High School

Abstract. The concept of emotional intelligence (EI) has attracted growing interest from researchers working in various fields. The present study examined the long-term stability (32 months) of EI-related abilities over the course of a major life transition (the transition from high school to university). During the first week of full-time study, a large group of undergraduates completed the EQ-i:Short; 32 months later a random subset of these students (N = 238), who had started their postsecondary education within 24 months of graduating from high school, completed the measures for a second time. The study found EI scores to be relatively stable over the 32-month time period. EI scores were also found to be significantly higher at Time 2; the overall pattern of change in EI-levels was more than can be attributed to the increased age of the participants.

Multi-Center Calibration of the Second Reference Material for Thromboplastin, Rabbit, Plain, Coded CRM 149R

1991 ◽  
Vol 65 (03) ◽  
pp. 263-267 ◽  
Author(s):  
A M H P van den Besselaar ◽  
R M Bertina
Keyword(s):  
Reference Material ◽  
Standard Error ◽  
Standard Errors ◽  
Sensitivity Index ◽  
Long Term Stability ◽  
Significant Bias ◽  
The Mean ◽  
The Relationship ◽  
International Sensitivity Index

SummaryIn a collaborative trial of eleven laboratories which was performed mainly within the framework of the European Community Bureau of Reference (BCR), a second reference material for thromboplastin, rabbit, plain, was calibrated against its predecessor RBT/79. This second reference material (coded CRM 149R) has a mean International Sensitivity Index (ISI) of 1.343 with a standard error of the mean of 0.035. The standard error of the ISI was determined by combination of the standard errors of the ISI of RBT/79 and the slope of the calibration line in this trial.The BCR reference material for thromboplastin, human, plain (coded BCT/099) was also included in this trial for assessment of the long-term stability of the relationship with RBT/79. The results indicated that this relationship has not changed over a period of 8 years. The interlaboratory variation of the slope of the relationship between CRM 149R and RBT/79 was significantly lower than the variation of the slope of the relationship between BCT/099 and RBT/79. In addition to the manual technique, a semi-automatic coagulometer according to Schnitger & Gross was used to determine prothrombin times with CRM 149R. The mean ISI of CRM 149R was not affected by replacement of the manual technique by this particular coagulometer.Two lyophilized plasmas were included in this trial. The mean slope of relationship between RBT/79 and CRM 149R based on the two lyophilized plasmas was the same as the corresponding slope based on fresh plasmas. Tlowever, the mean slope of relationship between RBT/79 and BCT/099 based on the two lyophilized plasmas was 4.9% higher than the mean slope based on fresh plasmas. Thus, the use of these lyophilized plasmas induced a small but significant bias in the slope of relationship between these thromboplastins of different species.

The Stability of the WHO Reference Thromboplastin NIBS & C 67/40

1979 ◽  
Vol 42 (04) ◽  
pp. 1135-1140 ◽  
Author(s):  
G I C Ingram
Keyword(s):  
Human Brain ◽  
Collaborative Study ◽  
Calibration Constant ◽  
Long Term Stability ◽  
Freeze Dried ◽  
Show Evidence ◽  
Human Material ◽  
Reference Preparation ◽  
The Stability

SummaryThe International Reference Preparation of human brain thromboplastin coded 67/40 has been thought to show evidence of instability. The evidence is discussed and is not thought to be strong; but it is suggested that it would be wise to replace 67/40 with a new preparation of human brain, both for this reason and because 67/40 is in a form (like Thrombotest) in which few workers seem to use human brain. A �plain� preparation would be more appropriate; and a freeze-dried sample of BCT is recommended as the successor preparation. The opportunity should be taken also to replace the corresponding ox and rabbit preparations. In the collaborative study which would be required it would then be desirable to test in parallel the three old and the three new preparations. The relative sensitivities of the old preparations could be compared with those found in earlier studies to obtain further evidence on the stability of 67/40; if stability were confirmed, the new preparations should be calibrated against it, but if not, the new human material should receive a calibration constant of 1.0 and the new ox and rabbit materials calibrated against that.The types of evidence available for monitoring the long-term stability of a thromboplastin are discussed.

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