Mobil

About: Mobil is a based out in . It is known for research contribution in the topics: Catalysis & Zeolite. The organization has 7085 authors who have published 10642 publications receiving 237497 citations. The organization is also known as: Socony-Vacuum Oil Company & Standard Oil Company of New York.

Decay of Phosphorescence from a Distribution of Trapping Levels

Abstract: In a previous paper it was shown that the usual model for second-order decay predicted the correct form for the decay in many thermoluminescent crystals but gave the wrong behavior for the parameters involved. Specifically, it was shown that $b$ and $m$ in the decay expression, $I={I}_{0}{[\frac{b}{(b+t)}]}^{m}$, should behave differently as functions of the decay temperature and the degree of trap filling than is observed experimentally at temperatures near or below the glow peak. In the present paper it is shown that the discrepancies can be accounted for by assuming a first-order decay from a distribution of trapping levels. Most of the results are based on a Gaussian distribution but it is shown that other distributions can produce similar results. The first-order mechanism is justified by considering the relative magnitudes of the rate constants for trap emptying, retrapping, and recombination. At temperatures well above the glow peak this assumption is no longer justified, but in this range the second-order decay predicts the observed results for $b$ and $m$. The effects of retrapping and of crystal dimensions are considered. Also, the effect on the glow peak of having a distribution of levels rather than a set of discrete levels is worked out and it is shown that the peak is broadened appreciably even for relatively narrow distributions.

Crystallization method employing microwave radiation

Abstract: A crystallization process employing microwave energy is described. The process is especially useful in the manufacture of porous crystalline materials.

Multistage process for converting oxygenates to hydrocarbons

Abstract: An integrated process is provided for converting methanol or the like to heavy hydrocarbon products, especially distillate range hydrocarbons. In a first stage catalytic process oxygenate feedstock is converted to lower olefins. Byproduct aromatics are passed through a second stage oligomerization reactor with olefins. Distillate range hydrocarbons are recovered and hydrotreated to provide an improved fuel product.