Dacryocystostomies par voieendonasale:indications et technique chirurgicale

Introduction : La dacryocystorhinostomie consiste à dériver le contenu du sac lacrymal directement vers la lumière de la fosse nasale correspondante en réalisant une large ouverture dans la paroi osseuse et muqueuse du sac, court-circuitant ainsi le canal lacrymonasal obturé. nous nous proposons, à travers cette étude rétrospective, de discuter les aspects techniques chirurgicaux de la dacryocystostomie par voie endonasale et de revoir les indications opératoires.Mots-clefs : dacryocystite ; dacryocystorhinostomie ; chirurgie endonasaleThe purpose of dacryocystorhinostomy is to derive the content of the lacrimal sac directly into the light of the corresponding nasal cavity by making a large opening in the bony wall and sac mucosa, by passing the blocked nasolacrimal duct. We intend, through this retrospective study, discuss the technical aspects of surgical dacryocystostomy by endonasal and review the indications for surgery.Keywords : dacryocystitis; dacryocystorhinostomy; endonasal surgery

Application of a standard risk assessment scheme to a North Africa contaminated site (Sfax, Tunisia) - tier 1

Phosphorus is a critical element to agriculture, consequently global phosphate rock demand will remain rising to feed a growing world population. The beneficiation of phosphorous ore gives rise to several tons of a waste by-product [phosphogypsum (PG)] which valorisation is limited, within other reasons, by the risks posed to environment and human health. Although threatening, the accumulation in stacks is the only procedure so far practiced by several countries as a means to get rid of this industrial externality. As part of a NATO Science for Peace Project (SfP 983311) this study describes the application of an environmental risk assessment (ERA) framework, to assess the risks posed by a PG stack to the surrounding soils, in Sfax, Republic of Tunisia. The ERA followed a weight of evidence approach, supported by two lines of evidence (LoE): the chemical (ChemLoE) and the ecotoxicological (EcotoxLoE). Integrated risks point for risk values greater than 0.5 in soils collected in PG stack surrounding area. Soil salinization, has likely contributed to the exacerbation of risks, as well as to the lack of consistency between both LoEs. This study highlights the need of rethinking the weight given to each LoE in ERA, in areas where soil salinization is a reality.publishe

Simulation of particles transport and coagulation during the RESS process

The rapid expansion of supercritical solution (RESS) is a promising process for the production of small particles with a narrow size distribution. It involves an expansion of a supercritical solution through a small nozzle to generate a rapid nucleation and then the formation of ultrafine particles. The particles are transported by a powerful jet developed in the expansion chamber. The particle size distribution (PSD) of the obtained fine powders depends on the hydrodynamic conditions in the pre- and post-expansion unit, the nature of solute-solvent system, as well as on the nozzle geometry, and diameter. In this work, we have developed a numerical simulation of both transport and Brownian coagulation of spherical particles in the expansion chamber by resolving the general dynamic equation (GDE). This simulation has permitted to control the temporal evolution of PSD characterizing each class of particles. These PSD field evolutions show that the particles of each class get round the Mach disk taking refuge on the jet boundaries where the Brownian coagulation is more pronounced. Therefore, these particles whose size depends on thermodynamic and geometrical conditions are deposited on the flat plate as a ring. We notice that the narrowest distribution function of the deposited particles on the flat plate is obtained for the largest nozzle orifice diameters and the lowest expansion pressure

Catalytic wet air oxidation of olive mill waste water over Ru/ZrO2

internationa

Ruthenium catalysts supported on TiO2 prepared by sol-gel way for p-hydroxybenzoic acid wet air oxidation.

International audienceThe wet air oxidation of p-hydroxybenzoic acid, chosen as a model compound of olive mills wastewaters was carried out at 140 degrees C and 50 bar air over Ru catalysts supported on TiO2 prepared by sol-gel method. These catalysts were characterized by means of N-2 adsorption-desorption, XRD and TEM. Optimization of the catalytic performances was obtained by studying some parameters such as the catalyst preparation method, the solvent evacuation way, the nature of the hydrolysis agent, the influence of the ruthenium salt used as the metal precursor (Ru(NO)(NO3)(3) or Ru(acac)(3)) and the catalyst pretreatment. The pre-calcination of the catalyst precursor at 300 degrees C under oxygen, before the reduction step under hydrogen, was detrimental to the activity. The results showed that the use of nitric acid as hydrolysis agent, drying under supercritical conditions and the use of Ru(NO)(NO3)(3) leads to the more efficient catalyst with high TOC abatement

Étude de l'élimination de bleu de méthylène dans l'eau par le charbon actif commercial CECA40


The removal of methylene blue(BM) through adsorption over the commercial actived charcoal ( CECA 40) was studied in a static batch reactor. At constant pH and temperature the adsorption equilibrium time is equal to 5 hours regardless of the initial concentration of metylene blue (BM). The adsorption in this case follows a Langmuir isotherm of the first type with an ultimate adsorption capacity of about 367,6 mg of methylene blue for each gram of CECA 40. Moreover, we observed no significant influence of temperature on the adsorption equilibrium. The adsorption and the Intraparticular diffusion kinectics were studied. Adsorption is clearly higher in an alcaline environment than in the acid one. This adsorption is further improved by the use of finer granulometry