Influence of operational variables on the photodegradation kinetics of Monuron in aqueous titanium dioxide dispersions

1994

The degradation of Monuron [N′—(4-chlorophenyl)—N, N dimethyl urea] in aqueous TiO 2 dispersions irradiated in the near-UV region has been investigated using a Pyrex batch photoreactor. The influence on the degradation kinetics of pH, initial Monuron concentration and catalyst concentration has been studied. The mineralization of the pollutant was also investigated. Measurements of photon absorbed flows allowed to determine the quantum yield values; they were found to increase by increasing the initial pH of the dispersion.

Nanochlorum eucaryotum — a green enigmatic alga: morphology, biochemistry and molecular biology

1994

In search of a natural systematic locality for algae — and also for other organisms — quite regularly the central question of evolution comes up. This proves as especially pertinent, when the taxonomic position of the most original phytoflagellates has to be considered. In the classical view of the direct filiation theory the ancestral phytoflagellata is positioned at the verge of the prokaryotic to the eukaryotic stage.

A Very Large Area Telescope for γ-Ray Astronomy Above 100 MeV Employing Limited Streamer Tubes

1994

A new detector for γ-ray astronomy above 100 MeV is described in which the electron-positron pairs are tracked by means of a set of plane arrays of Limited Streamer Tubes. This technique allows to build up very large area experiments which are specifically useful to study variable or transient sources.

Tassili

1994

Hacia un modelo espacial de la cultura de los Talayots de Mallorca

1994

Entrevista con Talib Rothegatter

1994

Entrevista con el Dr. D. Talib Rothegatter, Presidente de la División de Psicología del Tráfico y del Transporte (Traffic and Transport Psychology) dentro de la Asociación Internacional de Psicología Aplicada (International Association of Applied Psychology, IAAP). Tras la celebración del último Congreso Internacional de Psicología Aplicada, en que se produjo su nombramiento (23rd Internacional Congress of Applied Psychology) el preseidente de la Dividión analiza la situación presente y las perspectivas de futuro de la Psicología del Tráfico y Seguridad Vial como área de investigación y ámbito aplicado y profesional .

Esquisse d'histoire du domicile

1994

International audience

Testing Acute Toxicity in the Embryo of Zebrafish, Brachydanio rerio, as an Alternative to the Acute Fish Test: Preliminary Results

1994

Acute toxicity testing in fish is a standard method used in estimating the influences of chemicals on aquatic vertebrates. The ecotoxicological data obtained from acute toxicity tests in fish are, however, not sufficiently reliable to justify the continued use of this test. Fertilised eggs of zebrafish ( Brachydanio rerio) were used to test the acute toxicity of chemicals. They were chosen because the development of B. rerio has been studied extensively and information already exists concerning the normal development of this species. The following parameters of the development of B. rerio were observed: coagulation of the egg, gastrulation, number of somites, movement, development of organ…

Classical and Quantum Two-Dimensional Fluids in the Gibbs Ensemble

1994

We study the properties of model fluids in two spatial dimensions with Gibbs ensemble Monte Carlo (GEMC) techniques. In particular in the first part of the paper we study the entropy driven phase separation in case of a nonadditive symmetric hard disc fluid and locate by a combination of GEMC with finite size scaling techniques the critical line of nonadditivities as a function of the system density, which separates the mixing/demixing regions, we compare with a simple approximation. In the second part we successfully combine path integral Monte Carlo (PIMC) and GEMC techniques in order to locate the gas-liquid coexistence densities for a fluid with classical degrees of freedom and internal…

Towards efficient inductive synthesis from input/output examples

1994

Short-term recovery of benthos following disturbance from stream habitat rehabilitation

1994

The recovery of benthic macroinvertebrates after disturbance from stream rehabilitation was studied in the River Livojoki, northern Finland. The stream that had been channelized for log transport was rehabilitated on 1 July 1992 by digging holes and inserting boulders. We measured habitat characteristics and sampled benthic animals before and after rehabilitation, including an unrehabilitated control site. The immediate effect of rehabilitation was a slight decrease in the abundances of benthic insects. Recolonization occurred rapidly, within 10 days. Disturbance of the rehabilitation did not have a detectable effect on the macroinvertebrate community. Most species-level changes and communi…

Simultaneous uvbyβ Photometry and Hα Spectroscopy of Be Stars in Open Clusters

1994

The usual methods of spectral clasification, equivalent widths of Balmer lines or photometric calibrations are not suitable for the determination of the astrophysical parameters of the underlying star in Be-type objects. The spectrum is distorted by the circumstellar envelope lines, while the contribution of the envelope continuum radiation contaminates the photometric indices.

La pertinencia del análisis conversacional para la obtención de documentos orales

1994

Rational Species Extrapolation of Toxic Effects

1994

One of the main problems in toxicology and pharmacology is the extrapolation from one species to another, particularly from laboratory animals to man or in ecotoxicology from laboratory animals to free living species. Many toxicological data were raised only in one or a few species of laboratory animals. In the last decades more and more experimental data were obtained from in vitro-systems. Therefore extrapolations from in vitro to in vivo and from species to species are required. Species differences in uptake, distribution, metabolism, site of action, elimination and accumulation have to be taken into account. Most foreign compounds are metabolically transformed by diverse xenobiotica met…

Effect of Ti(IY) on some indicators of physiological activity inCapsicum annuum, L.

1994

SummaryPaprika pepper (Capsicum annuum, L., cv. Negral) plants grown in a greenhouse were supplied Ti(IV) ascorbate through the roots or through leaves. Biomass production, peroxidase (donor: H2O, oxidoreductase; EC 1.11.1.7) activity, and malic acid, starch and chlorophyll concentrations were determined in different plant organs. It was observed that Ti increased the concentration of some of the metabolites studied and promoted both peroxidase activity and biomass production. The profitable effect of the Ti treatments could occur because they enhance the availability of other nutrients. This effect could be due to the low redox potential of the Ti+3/Ti+4 system that catalyzes the activity …

Tendencias de la mortalidad por cáncer en españa, en especial del cáncer de pulmón, en comparación con otros países desarrollados

1994

ResumenSe estudia la evolución de la mortalidad global por cáncer en España (1970–1987), y especialmente por cáncer de pulmón, por sexos y grupos de edad, estableciendo comparaciones con otros países (EEUU, Inglaterra y Gales).En cuanto a la evolución de la mortalidad global por cáncer se observa que únicamente en las edades más juveniles se detectan descensos notables de la mortalidad, en tanto que, en los otros países con los que se compara, se observa también una disminución en edades más avanzadas. Asimismo, aunque las tasas de mortalidad por cáncer de pulmón en España tienen unos valores inferiores a los de los países mencionados, se observa un incremento de la mortalidad de ambos sexo…

Fuentes para el estudio de la diputación foral valenciana (siglos XVI-XVII)

1994

Les discours de rentrée aux audiences solennelles. Note méthodologique

1994

International audience

Les forces de la vie (18e siècle)

1994

International audience

La partició del terme general del marquesat de Guadalest en 1750 i les seues repercussions sobre l'estructura de la propietat de la terra

1994

Panel Summary One Model for Vision Systems?

1994

This panel reports some considerations about the definition of vision-models. The panellists are scientists working on vision problems from different perspectives. The concept of model in vision seems to remain still open. In fact, it is dynamic, and context dependent. There exists the need for a better exchange of information, among biologists, engineers, physicists, and psychologists in order to improve our knowledge.

Equilibrium Studies in Natural Fluids. A Chemical Speciation Model for the Major Constituents of Seawater.

1994

AbstractThe speciation of CI−, OH− and SO42- in synthetic sea water has been studied by Potentiometric measurements (pH-metric and ISE-Na methods) and by literature data analysis, using a well tested complex formation model. Stability constants, together with distribution of hypothesised species in synthetic sea water, as a function of temperature and salinity, are reported. The speciation model proposed in this work is discussed on the basis of chemical and statistical considerations. Comparison with some literature sea water models is given.

La novela deshumanizada española (1958-1988)

1994

La parábola de Carmen la Reina

1994

Validación cruzada de la estructura factorial de una medida multidimensional de la ansiedad laboral

1994

En el presente estudio se realiza una replicación del trabajo de Espejo (1993), con el objetivo de estudiar la estabilidad de la estructura factorial del Cuestionario de Ansiedad Laboral (C.A.L.) en una muestra multiocupacional (n=142). También se analizan las propiedades psicométricas de cada una de las subescalas hipotetizadas. Los resultados muestran, por una parte, que la estructura factorial hipotetizada presenta un ajuste ligeramente inferior en el presente estudio (SR = 0.114), y por otra, que las saturaciones de los ítems incluidos en la dimensión cognitiva son las más estables, mientras que las de los ítems de la dimensión conductual son las más inestables. Por último, los resultad…

Les arômes des vins et leurs défauts

1994

170 ref.; National audience

Hybrid Methods for Robust Irradiance Analysis and 3-D Shape Reconstruction from Images

1994

The analysis of the differential structure of images is an interesting task in machine vision, among other reasons because it can provide relevant featural representation of images, suited for higher level information processing task like geometry reconstruction and object recognition. The importance of invariants of the field of isophotae on lambertian surfaces in shape perception by means of chiaroscuro is discussed in (Koenderink and Van Doom, 1980). In their approach to shape from shading, (Breton et al, 1992) represent the shading of the image by means of its shading flow field, i.e. by the first order differential structure of the image expressed as the isoluminance direction and grad…

Production of Charmed Mesons In Z Decays

1994

The production of charmed mesons $$\mathop {D^0 }\limits^{( - )} $$ ,D ± , andD *± is studied in a sample of 478,000 hadronicZ decays. The production rates are measured to be $$\begin{gathered} \frac{{\Gamma ({\rm Z} \to D^{* \pm } X)}}{{\Gamma _{had} }} = 0.187 \pm 0.015(\exp .) \pm 0.013(BR), \hfill \\ \frac{{\Gamma ({\rm Z} \to D^ \pm X)}}{{\Gamma _{had} }} = 0.251 \pm 0.026(\exp .) \pm 0.025(BR), \hfill \\ \frac{{\Gamma ({\rm Z} \to \mathop {D^0 }\limits^{( - )} X)}}{{\Gamma _{had} }} = 0.518 \pm 0.052(\exp .) \pm 0.035(BR), \hfill \\ \end{gathered} $$ where the errors from this analysis are separated from those coming from theD branching ratios (BR). TheD *± momentum distribution is ex…

Mapping of Friedreich's ataxia locus by identification of recombination events in patients homozygous by descent

1994

The Friedreich's ataxia locus (FRDA) maps on chromosome 9q13. Genetic data, obtained from a small number of recombination events, indicated that the FRDA locus might be located centromeric to the D9S15/D9S5 linkage group, the most probable order being cen-FRDA-D9S5-D9S111-D9S15-D9S110-qter. Recently, new centromeric markers have been reported. Analysis of these markers allowed us to localize the recombination breakpoint in some of the recombinant families. However, only one proximal recombination has been found with these markers. To increase the genetic information from FRDA families, we have analyzed the centromeric markers FR1, FR2, FR7, FR8, and FR5 in patients homozygous by descent. Th…

Titanium-magnesium complexes with tetrahydrofuran as precursors of ethylene polymerization catalysts

1994

The titanium-magnesium complexes with tetrahydrofuran: [Mg(THF)6][TiCl5(THF)]2 (I); [(THF)4Mg(m-Cl)2TiCl4] (II); and [(THF)3Mg(m- Cl)3Mg(THF)3][TiCl5(THF)] (III), activated with organoaluminium compounds, show low catalytic activities in low-pressure ethylene polymerization, probably because of the high degree of titanium coordinative saturation in these compounds. The Mg:Ti mole ratio raised above 3 by ball-milling I, II, or III with [MgCl2(THF)2], followed by activation with triethylaluminium, has resulted in active catalyst polymerizing ethylene at rates up to 30 kg PE (g Ti h)-1. The catalytic activity varied in the ascending order: III < I < II. The characteristic parameters of the pol…

Distance Éducation : Economic Evaluation

1994

International audience

Recherches d’extréma par des méthodes d’extrapolation

1994

International audience

Zum Aufbau der Epiphysenfuge im chronischen Vitamin-A-Mangel — eine histologische und morphometrische Studie an der proximalen Tibiaepiphyse

1994

Vitamin A und analoge Substanzen (Retinoide) uben auf Wachstum und Differenzierung des Bewegungsapparates einen wesentlichen Einflus aus. In zahlreichen in vitro-Untersuchungen konnte gezeigt werden, das der Metabolismus von Chondrozyten und Osteoklasten durch toxische Vitamin A-Konzentrationen in komplexer Weise beeinflust wird [1]. Hingegen ist der physiologische Wirkungsmechanismus von Retinol bei der Wachstumsregulation des Knochens noch weitgehend unklar. Das Ziel der vorliegenden in vivo-Untersuchung war deshalb die morphologische Analyse der Epiphysenfuge an Ratten, wobei Tiere im chronischen Vitamin A-Mangel mit Kontrollen verglichen wurden.

Toimintakertomus 1993

1994

Évolution et diffusion de la pratique du tennis

1994

National audience; Implanté en Franche-Comté depuis le début du siècle, le tennis apparaît dans la région quarante ans après sa pénétration sur le territoire français. Très rapidement, en 1925, la pratique s'institutionnalise avec la création du Comité Régional de Lawn Tennis. La région compte alors sept clubs regroupant un peu moins de 200 joueurs.

Tratamiento quirúrgico de la fractura de acetábulo con luxación posterior de cadera: análisis retrospectivo de 20 casos

1994

Entre 1985 y 1990 fueron intervenidos en nuestro servicio 20 pacientes con fractura acetabular y luxación posterior de cadera, con edades desde 22 a 53 años, 18 (90%) eran varones. Los accidentes de tráfico fueron la causa de 18 (90%) de las lesiones. Diez (50%) presentaron lesiones asociadas de importancia. Se estudió su evolución con un seguimiento medio de 5 años (rango de 3.5 a 8.1). La fractura de pared posterior ha sido la que con mayor frecuencia se ha asociado a la luxación (50%), seguida de la transversa y de pared posterior (30%). Hemos obtenido 14 (70%) resultados satisfactorios; 2 pacientes precisaron artroplastia total a los 3 años. No se observó peor evolución en los casos de …