Proton NMR Analysis of Octane Number for Motor Gasoline: Part V

1992 ◽  
Vol 46 (10) ◽  
pp. 1548-1551 ◽  
Author(s):  
M. Ichikawa ◽  
N. Nonaka ◽  
H. Amano ◽  
I. Takada ◽  
S. Ishimori ◽  
...  

A method to predict the octane number of automobile gasoline containing methyl tert-butyl ether (MTBE) by proton magnetic resonance (PMR) spectrometry was studied. Samples of gasoline whose octane numbers had been identified according to the ASTM standards (commercially available premium gasoline to which MTBE was added at rates of 7 vol % and 14 vol %) were used in this investigation of the effect of MTBE on the octane number. The findings were utilized to introduce a term regarding MTBE into the previously reported linear regression equation for estimating the octane number from the PMR spectrum, and the appropriateness of the linear regression equation was assessed. As a result, the MTBE contents in the samples were determined with satisfactory accuracy by using a standard addition method, and a linear regression equation reflecting the effect of MTBE was obtained. These achievements are reported.

1992 ◽  
Vol 46 (3) ◽  
pp. 498-503 ◽  
Author(s):  
M. Ichikawa ◽  
N. Nonaka ◽  
H. Amano ◽  
I. Takada ◽  
S. Ishimori ◽  
...  

A method to evaluate the octane number of automobile gasoline by proton magnetic resonance (PMR) spectrometry has been studied. Twelve samples of marketed winter gasoline, whose octane numbers and compositions were identified according to the ASTM standards, and high-olefin gasoline were used to supplement the insufficient coverage of a previous report with additional data. Then, a linear regression equation regarding the relationship between the octane number and PMR data was prepared from the PMR spectra of the 21 samples used for the previous report, whose octane numbers were known, and the 12 samples used this time. Further, the appropriateness of the regression equation was assessed. This report concerns the results of a study in which the scope of the previous study, lacking sufficient data, has been supplemented with additional data to improve the accuracy of the visual estimation of the octane number using the pattern recognition method. Also, a linear regression equation was obtained and found useful for octane number estimation.


2013 ◽  
Vol 864-867 ◽  
pp. 973-977
Author(s):  
Han Xiao ◽  
Xiang Gao ◽  
Ming Zhe Li ◽  
Ming Ma ◽  
Long Zhang

The content of characteristic pollutants including methyl tert-butyl ether (MTBE) and benzene, toluene, ethyl benzene, p-xylene, m-xylene and o-xylene (BTEX) were determined by head-space-GC. A HP-FFAP capillary column was used in this method. In the mass concentration range of 14.8μg·L-1~1760μg·L-1, there were good linearity relationships between the GC peak areas and the mass concentrations of components with correlation coefficient above 0.999.The detection limits were in the rage of 2.0μg·L-1~2.3μg·L-1. Tests for recoveries and precision were made by standard addition method, values of recoveries and RSDs (n=6) found were in the range of 95%~105% and 0.8%~5.5%.


2019 ◽  
Vol 2 (1) ◽  
pp. 23
Author(s):  
Hayatun Nufus ◽  
Rezi Ariawan

This research is a correlational study that examines the relationship between cognitive style and habits of mind. The research subjects involved 4th semester students in the Department of Mathematics Education at the Faculty of Tarbiyah and Teacher Training of UIN Suska Riau which consisted of students with heterogeneous academic abilities. Cognitive style data was collected using the GEFT question instrument with test techniques. Habits of mind data were collected using a questionnaire instrument with a questionnaire distribution technique. The data analysis technique begins with the Pearson Product Moment correlation test which is continued with the significance test and the calculation of the magnitude of the relationship that occurs using the coefficient of determination. Because the data is positively correlated, it continues with determining the linear regression equation. The results showed that there was a significant weak correlation between cognitive style and habits of mind with a relationship score of 6% and a linear regression equation y '= 36.35 + 0.31 x.


1996 ◽  
Vol 33 (5) ◽  
pp. 369-378 ◽  
Author(s):  
Mark P. Mooney ◽  
Timothy D. Smith ◽  
Annie M. Burrows ◽  
Herbert L. Langdon ◽  
Cynthia E. Stone ◽  
...  

The purpose of the present study was to describe coronal suture pathology and cross sectional synostotic progression in an inbred strain of rabbits with congenital craniosynostosis. Calvaria from 102 perinatal rabbits (39 unaffected; 63 bilateral or unilateral synostosis) were collected at fetal days 21 (n = 12), 25 (n = 20), 27 (n = 22), 30 (term) (n = 32), and 3 days post-term (n = 16) for gross morphologic and histologic examination. Synostotic foci, the extent of relative bony bridging, and suture morphology were evaluated qualitatively and quantitatively. Of the 204 coronal sutures examined, 91 sutures were synostosed, and 113 were patent. All synostosed sutures showed similar foci by day 25, which originated as bony bridges in the middle of each suture on the ectocortic surface. Bony bridging width increased significantly (p < .001) from day 25 through 3 days post-term, and was best described by a linear regression equation. Osteogenic front areas of synostosed sutures were up to 2.5 times greater than patent sutures in term fetuses. Findings demonstrate that coronal suture synostosis in the congenital rabbit model (1) begins early during suture morphogenesis (before 25 days of gestation); (2) consistently radiates from a single focus corresponding to a normal interdigitating region (i.e., a high-tension environment); (3) varies in onset and rate as evidenced by low R2 value between age and extent of bony bridging; and (4) is the result of early hyperostosis of the osteogenic fronts and sutural agenesis. A number of possible pathogenetic mechanisms are discussed.


2011 ◽  
Vol 314-316 ◽  
pp. 763-766
Author(s):  
Dan Liu ◽  
Xiao Ting Xiao ◽  
Yi Juan Liao ◽  
Zheng Rong Zhang

To form the thick-plate with the tubular bulge, the backward and forward extrusion and punch process is proposed. The thickness of sheet metal, the inner diameter of tubular bulge, the diameter of punch-die, the forward extrusion depth and other process parameters are set by orthogonal regression design method and these groups of values are used respectively to simulate the combined extruding and punching process by the plastic analysis software DEFORM3D. And then, the linear regression equation is obtained between the bulge height and process parameters. The results indicate that the main factors affecting the bulge height are the thickness of sheet metal and diameter of punch-die within a certain range. However, the inner diameter of tubular bulge and the forward extrusion depth have a little contribute to bulge height. Also, the reliability of linear regression equation is not fine and the prediction model of tubular bulge needs to a more in-depth study.


1963 ◽  
Vol 12 (3) ◽  
pp. 238-246 ◽  
Author(s):  
Maurice V. Stack

SUMMARYWeights of mineralized dental tissue have been determined in incisors dissected from ten pairs of twins failing to survive beyond 7-8 months' gestation. Logarithms of weights were compared as ratios (lower/upper) with data from foetuses of similar development. Intra-twin differences were thus shown to be significantly less than inter-twin differences when comparing central incisors. Lateral incisors were too variable to allow this demonstration. The linear regression equation combining logarithms of lower and upper central incisor weights was suitable for estimating foetal age to within one week of the recorded age.


2012 ◽  
Vol 220-223 ◽  
pp. 1670-1674
Author(s):  
Fang Li Su ◽  
Sheng Yu Shi ◽  
Hai Fu Li ◽  
Tie Liang Wang

For providing refer to the experimental data of artificial floating island in river north, this study will get stability characteristics of artificial floating islands displacement pile fixation on simulating the impact of different flow rate of water. Analysising physical stress of artificial floating island displacement pile fixation and simulation, result shows that the sum of floating island of buoyancy and the maximum force of two fiber rope in the vertical direction should be greater than the maximum gravity of the floating island plants and ensure the maximum force of the two fiber rope in the horizontal direction must be greater than the flow momentum, the quality of floating island can be increased for improving stability. Depend on the different flow of water and linear regression equation, the distance between the floating island should be arranged reasonably.


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