L'estimation des ressources forestières en Belgique : méthodes et perspectives

Conference (1978, June)

Until now a national forest inventory design has never been considered in Belgium. Nevertheless a so called general census is realized every ten years since 1950 (the tenth since 1846). It chiefly ... [more ▼]

Until now a national forest inventory design has never been considered in Belgium. Nevertheless a so called general census is realized every ten years since 1950 (the tenth since 1846). It chiefly concerns various statistics of belgian forests (covering about 600.000 hectares) dealing with structure, owners, species, ages, volumes and financial values at administrative and forest levels. From a quantitative point of view (volume estimation) these statistics are not very reliable. In our opinion it would be important to complete and to standardize qualitative information by means of objective elements. These would be based upon samplings designs so that all people interested in forest production and its utilization can have a more precise idea of forest areas themselves, state of growing stock (types of volume included) and current rate of growth. According to the characteristics (dimension and structure) of many existing forests, such investigations could be made in two stages : - use of aerial photos to identify representative forest zones useful to be studied; - realization of a set of stratified systematic samplings (intensity : 2-3 ‰; area concerned: about 200.000 hectares) with combination of temporary and permanent circular plots (4-10 ares). [less ▲]

The pioneering investigations in the field of the interstellar molecules, 1935-1942.

in Astrophysics & Space Science (1978), 55(1), 263-265

Asteroid lightcurves simulated by the rotation of a three-axes ellipsoid model

in Astronomy and Astrophysics (1978), 66

A triaxial-ellipsoid model is used to simulate the smooth and nearly symmetric light curves that are usually characteristic of asteroids which exhibit large brightness variations. The mathematical model ... [more ▼]

A triaxial-ellipsoid model is used to simulate the smooth and nearly symmetric light curves that are usually characteristic of asteroids which exhibit large brightness variations. The mathematical model is developed and applied to two problems involving an asteroid moving with its rotational axis either perpendicular to or lying within the plane containing the sun and earth. The numerical results obtained are compared with Dunlap's (1971) simulations of asteroid brightness variations, and it is argued that typical asteroid phase coefficients cannot be interpreted unambiguously. The results are shown to favor the Hapke-Irvine relation for describing the scattering properties of a dark asteroid surface. [less ▲]

Infarctus du myocarde. Diagnostic précoce, évaluation quantitative des lésions.

Conference (1978, April 27)

Het woord in beeld : Afbeeldingen als contextelement in reclameadvertenties

Conference given outside the academic context (1978)

Fragmentation of penicillin catalysed by the exocellular DD-carboxypeptidase-transpeptidase of Streptomyces strain r61. Isotopic study of hydrogen fixation on carbon 6

in FEBS Letters (1978), 88(1), 147-150

Positions of the minor planets obtained in 1976 with the great objective prism of 40 CM /f equals 4 m/ of the ESO observatory at La Silla

in Astronomy and Astrophysics. Supplement Series (1978), 32

The results are presented of photographic observations of asteroid positions made in August 1976 at La Silla, Chile. The quality of the sky characteristics made it possible to record objects with the ... [more ▼]

The results are presented of photographic observations of asteroid positions made in August 1976 at La Silla, Chile. The quality of the sky characteristics made it possible to record objects with the magnitude 17. Measurements of all plates were conducted with the aid of the Ascorecord measuring machine of the Royal Belgian Observatory. The reduction method employed is based on the use of five reference stars. The equatorial planet coordinates can be easily obtained from the employed parameters with the aid of the formulas considered by Smart (1944). In the evaluation procedures use was made of the SAO catalog which had been recorded on magnetic tape by the Strasbourg Observatory. Three new asteroids were discovered. The obtained data are presented in two tables. [less ▲]

Large Scale Preparation of Purified Exocellular DD-carboxypeptidase-Transpeptidase of Streptomyces Strain R61

in Biotechnology and Bioengineering (1978), 20

The exocellular DD-carboxypeptidase–transpeptidase that Streptomyces R61 excretes during growth has been produced in large fermentation units of 15 m3 total capacity. The yield from 15,000 liter culture ... [more ▼]

The exocellular DD-carboxypeptidase–transpeptidase that Streptomyces R61 excretes during growth has been produced in large fermentation units of 15 m3 total capacity. The yield from 15,000 liter culture filtrate was 1.080 g purified enzyme (92% purity) with a total recovery of 29% and at least a 2000-fold increased specific activity. [less ▲]

Intérêt des paramètres biochimiques dans le pronostic à court terme de l'infarctus du myocarde

Conference (1978, March 23)

4U 1700-37

in IAU Astronomical Telegram N° 3290 (1978)

IAUC 3290 available at Central Bureau for Astronomical Telegrams.