bluuebunny/crossref_metadata_2025_split huggingface dataset:
Jean-Jacques Berzélius (1779-1848), associé de l'Académie Royale de Belgique : quelques réflexions à propos de son bicentenaire
Authors: Bruylants Albert 
Published: June 2020

Joens-Jacob Berzelius, the famous swedish chemist, was born on the 20th of August 1779. He studied at Upsala, where he was granted the doctorate in medecine (1804). Short after that, he was appointed to a chair at the university of Stockholm and dedicated himself, almost entirely, to chemistry. His course, illustrated by demonstrative experiments, became reknown troughout the chemical world.
He was made a member of the Royal Academy of Sciences (1808) served as its president (1810), and was elected standing secretary (1818).
Berzelius was an expert analyst ; he performed many quantative analysis. He was the discoverer of several new elements. The atomic weights, he had determined, appeared in his table (1818), with the new chemical symbols he had devised ; his electro-dualistic theory based on experiments, he had carried out with a large Volta pile, his new classification of minerals, based upon instead of physical properties on their chemical composition, he had established himself experimentaly, made him as the dominant figure of his time, despite the fact he was geographically distant from the principal chemical centers.
Several belgians were among Berzelius's numerous pupils, colleagues and friends.
B. Valerius translated his text-book from the german edition into the french (Brussels, 1838-1844). J. B. Van Mons, the father of the belgian chemists, introduced him as a foreign member of our Royal Academy (1817).
P. Louyet, who was a young and trusty follower, wrote his biographical sketch (1849).
M. Martens, as being an electro-chemist, was very familiar with the Swedish theory in this field, brought himself a valuable contribution to it and was also involved in the controversy, J. B. Dumas versus J. J. Berzelius, about the theory of substitution processes (1840).
Last but not least, J. J. Stas and L. Melsens, two young coworkers of J. B. Dumas took an active part in this controversy, one of the most violent in the course of XIX century.
L'effet inhibiteur de l'oxygène sur le développement du cancer pulmonaire chez la souris
Authors: Duchesne Jules 
Published: June 2020

The aim of this Note is to confirm the mechanism of the biochemical process governing the maligment tumours described in the author's earlier work.
The method implies the use of oxygen under high pressure which, as it has in these conditions the peculiar property to destroy antioxydant compounds, leads, as expected, to a significant decrease in the number and size of induced lung metastases.
These results consequently open up important new perspectives in the field of the therapeutic for cancer.
Sur un théorème de Vitali-de Possel
Authors: Lomami Okito 
Published: June 2020

Le but essentiel de cette note est d'établir dans un cadre plus général et sous des conditions plus larges un théorème de dérivation de R. de Possel pour les bases de dérivation fonctionnelle de Vitali fortes.
Soient D une base de dérivation fonctionnelle de Vitali forte dans un espace mesuré (E, ℳ, φ) et ψ une mesure positive sur ℳφ- dérivable. En désignant par Dψ et Dψ respectivement la D- dérivée inférieure et la D- dérivée supérieure de ψ, et par ƒ une φ- dérivée de ψ, nous démontrons que, sous certaines conditions, on a localement presque partout Dψ > ƒ et ƒ > Dψ. Le théorème en résulte puisque Dψ < Dψ
Influence de l'introduction d'un terme d'amortissement à argument retardé dans l'équation de Van der Pol
Authors: Bastin Henri , Delchambre Monique 
Published: June 2020

On étudie un système de Van der Pol à argument retardé et on montre que l'allure des courbes de réponse dans le plan d'Andronov dépend fortement du retard.
De plus, les zones de stabilité sont considérablement modifiées par rapport au système non retardé.
Bouncing Quantum Cosmologies
Authors: Demaret Jacques 
Published: June 2020

Spatially homogeneous cosmological models of Bianchi types I, V and IX (as well as their isotropic counterparts : the Einstein-de Sitter, open and closed Friedmann-Robertson-Walker (FRW) models, respectively), filled with a perfect fluid with an equation of state of the type p = (γ - 1 )ρ (γ = constant comprised between 1 and 2) are quantized in the framework of an ADM-type canonical quantization scheme introduced by Demaret and Moncrief.
This method which generalizes a method due to Lund and originally restricted to space-times filled with a pressureless fluid (p = 0) is based on Schutz's Hamiltonian theory of a relativistic perfect fluid, extending to general relativity Seliger and Whitham's velocity-potential version of classical hydrodynamics. It leads to a Schrödinger-like equation for the wave function of the universe, which admits a true physical interpretation in terms of probability as in orthodox quantum mechanics.
Contrary to Misner's early results based on a different quantization scheme, our method leads to the conclusion that, apart from a set of measure zero of models comprising FRW models as well as Bianchi models filled with a fluid with a stiff equation of state (p = ρ), all Bianchi models are non-singular, in the sense that the quantum wave function becomes zero at the classical singularity. Such a non-singular model can be interpreted as a contracting universe bouncing into an expanding universe, due to quantum gravitational fluctuations. A similar conclusion of non-singularity of a quantum Bianchi I universe has recently been obtained by Narlikar by using a different method of quantization, i.e. the method of path integration.
Studies of spinels. (VIII) Synthesis and structural study of new antimonates M5II M3III SbO12 by X-ray diffraction and Mössbauer spectroscopy
Authors: Preudhomme J. , Tarte P. , Kenens R. , Grandjean F. , Gérard A. 
Published: June 2020

X-ray and Mössbauer data on spinel antimonates, with formula (MII2MIII3) [MII8MIII2Sb2]O24, with MII = Mg, Zn, Ni and MIII = Fe, Ga are presented.
The cationic orderings and distributions are widely discussed and even if no long-range cationic ordering appears, the Mössbauer data show a short-range one.
Preliminary magnetic results are also obtained.
Télescope et observation du rayonnement cosmique à Lubumbashi
Authors: Dehousse M. E. 
Published: June 2020

In this work the cosmic radiation telescope which we have constructed and which is functioning at Lubumbashi is described. Due to its two orientale detectors, it counts high energy particles which go through it, and permits the most energetic radiation to be disclosed. Some of the observation results on the cutting of horizontal and vertical symetrical cosmic rays have been analysed by us, and their great energetic stability is concluded.
A few hypothesis relative to the laws which preside the behaviour of the rays and to the succession of beats in functional and coincidental gauges are put forward. The perturbations created by a magnetic screen are related and valued.
The interpretation of protons and electrons observations from ATS 6 satellite within the frame of Mcllwain's electric field model
Authors: Lemaire Joseph 
Published: June 2020

The "E3H" electric field model has been deduced by Mcll-wain from dynamical proton and electron energy spectrograms measured along the geostationary orbit of ATS 5 satellite. It is shown that this empirical model, which has often been regarded with some reticence by a number of theoreticians, fits well with the measurements, also made in the equatorial region of the magnetosphere, onboard another geostationary satellite (ATS 6) during an extended period of time when the geomagnetic activity index ranged be¬ tween 1 and 2. This confirmation validates the E3H model, at least for such extended periods of time when Kp= 1 and 2+.
From the dynamical spectrograms of ATS 6 observed on 19 July 1974, some evidence for patchy or localized injection of a magnetosheath plasma cloud across the late afternoon local time sector of magnetopause has been gained.
Les niches écologiques des Carabides en milieu forestier I. Composantes spatio-temporelles
Authors: Loreau Michel 
Published: June 2020

An overall study of the niches of forest carabid beetles is carried out in a beechwood close to the climax stage in Lembeek (Belgium). A comparison with two other biotopes — a pine plantation and a grassland in process of afforestation — further aims at defining general features of niche organization in forest carabid communities. Four niche components are measured : annual activity cycle, daily activity rhythm, spatial distribution, and diet. This first paper deals with the three temporal and spatial components.
Annual activity cycles are unexpectedly diversified, and thus play an important part in niche différenciation. The well marked succession of activity peaks during the course of the year separates most forest species in time. On the other hand, niche overlap is higher in the «grassland», especially among dominant species, suggesting that time organization is poorly achieved in a successional stage.
Daily activity rhythm constitutes a minor factor in niche differentiation. Most forest carabids are nocturnal ; but a few spring species are day-active.
Spatial distribution of activity does not generally allow a clear-cut niche separation either. When becoming dominant, large forest species tend to reach an homogeneous distribution of activity. In the «grassland» however, distributions are particularly heterogeneus, and point out two distinct faunas typical of different successional stages.
Théorie du champ pictural : Les facteurs spatiaux - L'ensemble du champ
Authors: Guiraud Jean , Lison Pierre 
Published: June 2020

Sachant ce que sont les interactions des couleurs et les interactions des luminosités dans l'œuvre picturale, on se propose ici de leur associer les interactions de type spatial, soit celles des facteurs qui régissent la forme et la distribution des plages colorées.
(Ce texte modifie celui qui avait été publié sous ce titre et dans ce Bulletin en 1979).
À propos de l'effet Brody
Authors: Troquet J. 
Published: June 2020

In order to recognize what comes from anyone, we have situated the Brody effect into its electrodynamical frame, and we have underlined some important potentialities that we consider as neglected : that is appendix III in the opus princeps.
Such a tool is powerful in working out the multilayer problem but, without illustration, its compactness is not attractive. We also present an other formulation from which the Brody effect may be more clearly defined.
Towards intelligent weapons
Authors: Jaumotte André Louis 
Published: June 2020

Au moment où la réduction de la menace force à repenser la stratégie militaire et à revoir les priorités de la défense, nous sommes à la veille d'un saut qualitatif sensible conduisant à une panoplie d'armes et de systèmes d'armes intelligents.
Des capteurs performants fournissent les informations de base en filtrant l'ess¬ entiel de l'accessoire.
Les principaux senseurs sont les sonars, les radars et les caméras infrarouges. Pour chacun d'eux, des progrès importants viennent d'être accomplis. Sonar à basse fréquence. Radar à commande de phase. Caméras infrarouges avec semi-conducteurs refroidis à une température cryogénique.
Lorsque les opérations de détection, fusion et identification sont accomplies, l'arme dispose d'une représentation objective de son environnement perçu. Toutes les techniques de l'intelligence artificielle sont alors utilisées pour en déduire une conduite à tenir pour effectuer la mission.
Ces armes intelligentes sont très en avance sur la stratégie militaire faite par des hommes non formés à ces armes intelligentes.
On the measure of non-compactness for a class of singular integral operators
Authors: Nugari Rita 
Published: June 2020

We study a linear integral operator over the interval (— ∞, ∞). The operator is well defined and continuous from L1 (ℝ) into L2 (ℝ) but fails to be compact. Bounds are given on its measure of noncompactness.
AMS Subject Classification -45P05 -47G05.
Mathematical Foundation of a Non-linear Treshold Logic. A new Paradigm for the Technology of Neural Machines
Authors: Dubois Daniel M. , Resconi Germano 
Published: June 2020

This paper deals with the foundation of a Non-linear Threshold Logic as a significative extension of the classical Threshold Logic initiated by McCulloch and Pitts 50 years ago. The mathematical theory of this new logic is based on Heaviside a Non-linear argument of the Function. The determination of the parameters is made by an algebraic learning. For the first time, we introduced the so-called Heaviside Fixed Function.
The models of the Dubois' Fractal Neural Network and the Fukushima et al Neocognitron give the original framework of the new Non-linear Threshold Logic.
The Threshold Logic, using linear argument of the Heaviside function, is not capable of resolving all Boolean functions with only one neuron.
It is demonstrated that our Non-linear Threshold Logic resolved all the Boolean functions with one single neuron for any number of inputs, ie even the XOR problem.
This is a good test for our method. Moreover it is shown that the very difficult Parity problem has also a very elegant solution for obtaining the parity of any Boolean patterns from one single neuron with any number of inputs.
In the technology of neural networks, the back-propagation methods are based on hidden neurons to resolve the Boolean functions. There are some difficulties to obtain the global minimum as the number of neurons increases and the combinatorial explosion gives many problems for practical applications.
The Non-linear Threshold Logic will permit to diminish a great quantity of neurons in the neural networks with the back-propagation.
The possibilities of bigger practical applications are so given by this Non-linear Threshold Logic in the technology of neural machines due to the diminution of the necessary number of neurons and so to avoid some combinatorial explosion problems. Turbo Brain 1.0, a package for Personal Computers, has been developped from this Non-linear Threshold Logic with a Symbolic software.
Motion of charged particles in a stochastic magnetic field with a collisional noise
Authors: Wang Haida , Balescu Radu 
Published: June 2020

The diffusion of charged particles in a gaussian stochastic magnetic field characterized by finite correlation lengths λI and λ[formula] and gaussian coloured collisions with a finite correlation time τc is studied through the method of expansion with respect to a parameter ε which is introduced to denote the order of smallness. The mean square displacement in the perpendicular direction, Γ(t), is derived to the order of ε2. Several limiting cases are discussed and
shown to recover the previous results. To the order of α5 [formula], the
result is the same as that of Balescu, Misguich and Nakach, which was obtained after " Corrsin approximation It proves that the " =Corrsin approximation" is also reasonable in the short time regime.
Étude qualitative d'une équation différentielle, décrivant un processus thermique transitoire
Authors: Aprahamian Bohos , Kontrov Sava , Terzian Stépan , Aprahamian Méliné 
Published: June 2020

L'objet de l'article est l'étude qualitative d'une équation différentielle du deuxième ordre, décrivant le processus thermique transitoire d'un grand nombre d'appareils électrothermiques qui possèdent un schéma substituant thermique contenant une source de flux thermique, deux capacités et trois résistances thermiques. Les zones des solutions stables autour des points fixes de l'équation sont trouvées. L'application des résultats obtenus est illustrée par un exemple concernant l'utilisation d'un nouvel élément de chauffage, qui a une caractéristique de relais de la résistance spécifique électrique dépendant de la température.
Vu les résultats obtenus, des études semblables sont à effectuer pour tout autre élément de chauffage.
An Existence Theorem of Solutions of Semilinear Equations in Reflexive Banach Spaces and Its Applications
Authors: Tang Chun-Lei 
Published: June 2020

In this paper, we first obtain an existence theorem of solutions of semilinear equations in reflexive Banach spaces with the dual least action principle and the perturbation method, then apply it to Hamiltonian systems and second order systems.
Key works : subdifferential, generalized gradient, Fenchel transform, minimum, weakly lower semicontinuous.
Evolution récente des méthodes d'analyse des images satellitaires par télédétection numérique
Authors: Wilmet J. 
Published: June 2020

This article is an attempt to sum up the evolution of remote sensing image interpretation methods during the last years. The land cover identification has made a very significant progress in different ways. The enhancement of the spectral methods proceeds from the adaptation to remote sensed data from already known techniques such as fuzzy logics as well as from new developments such as multitemporal vectors. Considerable improvements occured also among textural methods, such as conditional filtering, backpropagation neural networks or mathematical morphology.
However, the interpretation of land use patterns remains an open problem. Its comparative backwardness, as far as digital methods are considered, arises from a lack of conceptual analysis of the image structure which remains always a prevalent domain of thematic studies.
Potential Scattering in Single Subdynamics
Authors: De Haan Michel , George Claude D. 
Published: June 2020

The authors have presented [1] a subdynamics theory in which quantities characteristic of irreversible behaviour - such as that of a collision process - appear in the generator of kinetic evolution. This theory is applied to the simple case of potential scattering. The original dynamics is first widened after incoming, outgoing and intermediate degrees of freedom are distinguished. An extended concept of vacuum state is introduced by reference to the observational situation of interest. The redundant degrees of freedom are then constrained by the requirement that the physi¬ cal evolution takes place entirely in the subdynamics associated with that vacuum. The relationship with previous treatments of the same system is analysed in some detail.
PACS numbers : 05.30 ; 02.90 ; 11.20.
Choc de cultures : l'université et l'entreprise. Les «spin-offs» universitaires
Authors: Jaumotte André Louis 
Published: June 2020

Une «spin-offs» universitaire est une entreprise constituée au départ de l'Université et de membres de la communauté universitaire pour exploiter commercialement des connaissances ou des résultats de recherches issus de l'Université.
Culture universitaire et culture d'entreprise n'ont pas le même objectif. Pour l'Université, le but est l'enseignement, la recherche et le service à la communauté ; l'entreprise vise à créer de la valeur économique. Les deux cultures sont complémentaires et elles étaient quasi sans recouvrement.
Les «spin-offs» universitaires changent cette vision en liant l'Université à la création de valeur économique.
Après un panorama des «spin-offs» universitaires (au 31 janvier 1999), on en fait l'analyse au point de vue des faillites, du chiffre d'affaires, de la création d'emplois, de la valeur ajoutée et de l'autonomie financière.
On met en évidence les phases successives allant de l'idée à sa commercialisation par «spin-offs».
On observe les bonnes pratiques quant à l'évaluation d'un projet, au rôle des incubateurs, des centres d'entrepreunariat, aux partenaires financiers.
En conclusion, trois éléments ont modifié le paysage de la création d'entreprises en Europe : le développement de l'Union européenne, l'évolution du capitalisme et le développement des réseaux.
Une quatrième mission s'ajoute ainsi aux trois missions traditionnelles de l'Université, la valorisation commerciale de sa recherche. Les Universités belges s'y sont engagées à des degrés variables.
Incinérateurs, crise dioxine, et risques sanitaires pour la population belge
Authors: Bernard Alfred , Depauw Edwin , Fierens Sébastien , Mairesse Hélène , Hermans Cédric , Broeckaert Fabrice , Focant Jean-François 
Published: June 2020

Incinerators, dioxin crisis and health risks for the general population in Belgium.
Bernard A., Fierens S., Mairesse H., C. Hermans, F. Broeckaert, J.-F. Focant, E. Depauw.
Since a few years, there is some concern in Belgium about the potential health risks of dioxins emitted by municipal solid waste incinerators (MSWI) and more recently by the dioxins which were introduced in the food chain during the Belgian PCB incident. This communication reports studies which have been recently carried out to assess the possible health impact of dioxins in these two sit¬ uations. Dioxins (PCDDIFs ) were determined in the blood of 85 subjects living around two MSWI, one localized in an industrial area and the other in a rural area. By comparison with an age-matched control group of 27 subjects living in an unpolluted area, an increase of dioxin body burden (36,7 vs 24,3 pg TEQlg blood fat, 34 % on average) was found only in the vicinity of the MSWI in the rural area, most likely because of a higher consumption of locally produced foods around this incinerator. However, despite this increase, all subjects had dioxin levels still in the range of values reported in unpolluted areas in Europe. As to the dioxin crisis, the contamination was too limited in time and in the food chain to have caused adverse health effects in the general popula¬ tion of Belgium even if most contaminated foods (e.g. chicken meat) had dioxin levels more than 100 times above tolerance levels. Indeed, a doubling of the PCB and dioxin burden of the young adult population would have required the consumption of respectively 10 and 20 highly contaminated meals. In view of the very limited proportion of the food chain affected by the incident (less than 2% of poultry farms and of 0.1% of all farms in Bel¬ gium), such an extreme scenario was quite improbable at the pop¬ ulation level. It was conceivable only in farmers who could have consumed their own products. But even for these farmers, this would mean that their PCB and dioxin body burden would have been increased at levels of the 80s or of subjects regularly eating contaminated seafood.