With the development of highly-deviated well cementing techniques, rotating casing cementing technology has got more and more attention. The rotating casing technique can improve the displacement efficiency of cement paste, and then enhance the quality of well cementation. In the stuck section, the rotating casing can redress the well to make the casing run sequentially. The casing endures shea...

Indicators are used to quantify the pressure of pesticides on the environment. Pesticide risk indicators typically require weighting environmental exposure by a no effect concentration. An indicator based on spread equivalents (ΣSeq) is used in environmental policy in Flanders (Belgium). The pesticide risk for aquatic life is estimated by weighting active ingredient usage by the ratio of their ...

A short-time exposure on the concentration--time relationship base, a classification of substances according to the degree of hazard and the program for assessing safety coefficients have been suggested in order to predict the basic toxicometric parameters (chronic exposure thresholds, maximum allowable concentrations, safety coefficients, and others).

Swordfish (Xiphias gladius L., 1758) is an apex predator, highly migratory meso-pelagic fish widely distributed in the Atlantic Ocean and Mediterranean. As top predators, this fish may be the end reservoir of the bioaccumulation of trace elements in a food chain because they occupy higher trophic levels and are an important food source, causing them to be potentially hazardous to consume. This ...

In connection with "maximum allowable concentrations in biological materials ", I should like to express some views on the value of measuring mercury and cadmium concentrations in urine. These remarks are based on findings in human subjects and in experimental animals. Mercury which is absorbed into the body is largely excreted in the urine. From this. aspect, therefore, determination of the ur...

This article summarizes an evaluation of the Maximum Allowable Cost (MAC)-Estimated Acquisition Cost (EAC) program, the Federal Government's cost-containment program for prescription drugs. The MAC-EAC regulations which became effective on August 26, 1976, have four major components: (1) Maximum Allowable Cost reimbursement limits for selected multisource or generically available drugs; (2) Est...

The maximum allowable biological concentration of a toxic substance is the highest concentration which can be found in a biological medium without damage to health. The biological materials rna y be examined for: (a) the toxic substance itself; (b) a product of the metabolism of the toxic substance in the body; (c) a substance derived from the physiopathological activity of the toxic substance;...