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J Defrancq

Publications and source records attributed to J Defrancq.

5 recordsLinked to original sources
PubMed2003

A new one-dimensional clarifier model--verification using full-scale experimental data.

A new one-dimensional clarifier model was developed, including components of existing models, and extended with a height-dependent cross-sectional area and two flowrate-dependent dispersion coefficients. This model is evaluated using data from a detailed one-month measuring campaign on a full-scale wastewater treatment plant. The data included hourly sludge concentration profile, sludge heights at 10 minute intervals, sludge concentrations in inlet, effluent and recycle flows and regular settling properties characterised by batch setting tests. Due to the poor quality concentration measurements at the surface of the clarifier, the model was not calibrated to perform well in concentration predictions at this surface. However, excellent descriptive capabilities were obtained for sludge profiles and blanket level. The Cho et al. setting velocity function was found to be significantly better in terms of description capability than the more traditional Vesilind function.

Calibration↗
PubMed2001

[Less invasive sinus lift using the technique of Summers modified by Lazzara].

The sinus floor elevation (sinus lift) is a procedure used for treating patients with very large pneumatisation of the maxillary sinus and thereby with severe atrophic maxilla (height of the residual alveolar bone between 5 and 8 mm). A modification of this technique is the osteotome sinus floor elevation: this is a less invasive method of creating sites with osteotomes by crestal approach in locations with insufficient bone for insertion of oral implants. With larger osteotomes, bone graft substitutes are placed through the osteotomy site to provide a sinus floor elevation and an augmentation of the crestal bone. Therefore, via the osteotome technique, longer oral implants can be inserted.

Adult↗
PubMed2001

[Chin grafts].

This article describes various procedural steps undertaken during the chin graft technique used in our department. The recommendations and possible complications are described in detail and discussed using the scientific literature. A short theoretical introduction on bone healing is presented in order to better explain the proposed techniques.

Bone Regeneration↗
PubMed1993

Duplex ultrasonographic evaluation of liver transplants.

Two hundred and twenty-two duplex ultrasonographic examinations were performed on 36 liver transplants in 30 patients over a period of 5 years and 9 months. Positive sonographic findings were correlated with 13 angiographic examinations. Arterial complications included 4 thromboses, 5 stenoses, and one mycotic aneurysm. A false-negative result was obtained in 2 cases of stenosis and a false-positive result in one case of thrombosis. One portal vein thrombosis, 2 stenoses, and 2 cases of portal hypertension were diagnosed correctly. Sensitivity was 87%, specificity 95%, and accuracy 93%. Duplex Doppler was least effective in the diagnosis of hepatic artery stenosis. Five cases showed biliary complications of ischemic origin. Angiography is indicated when duplex Doppler is positive or doubtful, but also when the clinical condition is unclear.

Adult↗