The relationship between aromaticity, vitrinite reflectance and maceral composition of coals: Implications for the use of vitrinite reflectance as a maturation parameter

✍ Scribed by A.D. Carr; J.E. Williamson

Book ID: 116094156
Publisher: Elsevier Science
Year: 1990
Tongue: English
Weight: 973 KB
Volume: 16
Category: Article
ISSN: 0146-6380
DOI: 10.1016/0146-6380(90)90051-z

No coin nor oath required. For personal study only.

📜 SIMILAR VOLUMES

A relationship between the carbon and hy

A relationship between the carbon and hydrogen content of coals and their vitrinite reflectance

✍ J.R. Smith; J.W. Smith 📂 Article 📅 2007 🏛 Elsevier Science 🌐 English ⚖ 899 KB

An empirical relationship between carbon and hydrogen contents of coals and their measured vitrinite reflectances R v, max (henceforth R o ) determined from published data for 210 samples of Australian coals from more than 60 different seams, shows that R o depends upon both the carbon and hydrogen

The use of automated coal petrography in

The use of automated coal petrography in determining maceral group composition and the reflectance of vitrinite

✍ Jin Kuili; Xia Jian; Hao Duohu 📂 Article 📅 1988 🏛 Elsevier Science 🌐 English ⚖ 630 KB

Relationship between the maximum and the

Relationship between the maximum and the random reflectance of vitrinite for coal from the Upper Silesian Coal Basin (Poland)

✍ Joanna Komorek; Rafał Morga 📂 Article 📅 2002 🏛 Elsevier Science 🌐 English ⚖ 100 KB

Saliva and serum samples were collected

Saliva and serum samples were collected from eight healthy volunteers every two hours during a 26-hour period. Melatonin concentrations were measured by radioimmunoassay after chloroform extraction using radioiodinated melatonin as a tracer. Five of the subjects had high serum melatonin levels at night (peak levels higher than 75 pg/ml); in three subjects the highest serum melatonin concentration was 20-40 pg/ml. All subjects had low levels (P <0.001, was obtained for all detectable value pairs (n= 73). The regression and correlation coefficients were almost equal for the peak values of melatonin and during the rising and descending phases of the secretion patterns. However, no significant correlation was found between low daytime salivary and serum concentrations when calculated separately. In the five high-secretors the melatonin levels in saliva reflected reliably the changes in serum, but in the three low-secretors the correlation between salivary and serum melatonin was not significant. The proportion of melatonin found in saliva decreased with increasing serum melatonin levels. Circadian rhythm parameters were estimated by single cosinor analysis. The acrophases did not differ significantly within a subject in the concomitant measurements of serum and salivary melatonin. The measurements of salivary melatonin levels seem valid for studies on melatonin rhythms, but the melatonin concentrations measured in saliva do not always consistently reflect the absolute concentrations in blood.

✍ Maija-Liisa Laakso; Tarja Porkka-Heiskanen; Aino Alila; Dag Stenberg; Gunnar Joh 📂 Article 📅 1990 🏛 John Wiley and Sons 🌐 English ⚖ 622 KB