Innovative process routes for a high-quality concrete recycling.

This study presents alternative methods for the processing of concrete waste. The mechanical stresses needed for the embrittlement of the mortar matrix and further selective crushing of concrete were generated by either electric impulses or microwaves heating. Tests were carried out on lab-made concrete samples representative of concrete waste from concrete mixer trucks and on concrete waste collected on a French demolition site. The results obtained so far show that both techniques can be used to weaken concrete samples and to enhance aggregate selective liberation (that is the production of cement paste-free aggregates) during crushing and grinding. Electric pulses treatment seems to appear more efficient, more robust and less energy consuming (1-3 kWh t(-1)) than microwave treatment (10-40 kWh t(-1)) but it can only be applied on samples in water leading to a major drawback for recycling aggregates or cement paste in the cement production process.

Process-based analysis of waste management systems: a case study.

This paper presents an analysis, using process simulation, of the waste management system applied in a collection basin located in the south of Paris (France). The study was conducted in close cooperation with the "SYCTOM of Paris agglomeration", an operator in charge of managing 2.5 milliontons/yr of municipal solid waste in the Paris area. The analysis includes a description of the current situation of waste management in this collection basin, the construction and calibration of a simulator that reproduces this situation, the simulation of scenarios that account for possible future changes in waste flows and treatment options and finally a comparison of scenario results. Results illustrate the interest of a process-based approach to waste management systems. Such an approach is complementary to life cycle analyses, which usually rely on more generic descriptions of waste treatment units. The detailed analysis of a waste management system using local data on waste streams and treatment units provides technical indicators of system efficiency expressed in terms of recycling rates, energy recovery, emission fluxes and costs. Such information can help reach a consensus with respect to the actual situation of waste management and provides decision-makers with quantitative arguments that can be brought into the public debate.

[Transvaginal ultrasound and voiding disorders after TVT procedure]. / Echographie endovaginale et troubles mictionnels après TVT (Tension-free Vaginal Tape).

OBJECTIVE: This study was carried out to evaluate the ultrasonographic findings on patients with voiding disorders after the tension-free vaginal tape procedure (TVT). PATIENTS AND METHOD: Fifty-four women had ultrasonographic evaluation 3 months after TVT procedure. The prolene tape position was evaluated with a complete sagittal view and the width of the tape and the distance between the bladder neck and the tape were measured. In the same time, patients completely cured by TVT (group 1), postoperative dysuria (group 2), de novo urge incontinence (group 3) and ineffective treatment were evaluated with a self-questionnaire and physical examination. Statistical analysis was performed using ANOVA test. RESULTS: The distance between the tape and the bladder neck shows a significant difference between group 1 and 2 (13.2 mm compared to 7.6 mm) and between group 1 and 3 (13.2 mm compared to 17.7 mm). The width of the tape is significantly different between group 1 and 2 (8.8 mm compared to 6.6 mm) and between group 1 and 3 (8.8 mm compared to 6.5 mm). The distance between the tape and the bladder neck in group 2, compared with group 3, is significantly shorter (7.6 mm compared to 17.7 mm). There is no difference between the width of the tape between groups 2 and 3 (6.6 mm compared to 6.5 mm). DISCUSSION AND CONCLUSION: These results show a correlation between voiding disorders after TVT procedure and transvaginal ultrasonographic measurement of the distance between the prolene tape and the bladder neck.

[CT enteroclysis for detection of small bowel tumors]. / L'enteroscanner: une nouvelle methode d'exploration du grele.

PURPOSE: To assess the feasibility and the usefulness of CT enteroclysis (helical CT with enteroclysis) in detecting small bowel tumors. MATERIALS AND METHODS: Fifty patients were referred for suspicion of small bowel tumor. CT enteroclysis is performed by injecting a large volume of water using a pomp through a nasojejunal tube followed by a thin section helical acquisition. RESULTS: Forty-eight helical CT enteroclysis were performed in order to detect 25 small bowel tumors. Among them 22 were confirmed by histological study. The mean size of tumors was 23 mm. In 12 of 17 cases, diagnosis was missed or incomplete at conventional barium study. Enteroscopy was performed in 12 of 22 cases, with discordant result in one case and incomplete result in 3 cases. In 8 cases, including 5 carcinoid tumors, patients had surgery after CT enteroclysis only, enteroscopy would probably have not made the diagnosis because the lesions were far from the duodenojejunal junction and ileocaecal valve. CONCLUSION: Helical CT enteroclysis is a new method for detecting small bowel tumors, easy to perform, well tolerated. It seems to be more sensitive than conventional barium studies and less invasive than enteroscopy. Tumor characterization and staging can be performed using a single examination. It seems to be justified to perform CT enteroclysis to detect small bowel tumors or in the evaluation of patients with polyposis.

[Ectopic pancreas located in the small bowel: CT-endoscopic appearance. Apropos of two cases]. / Pancréas ectopiques à localisation intestinale: aspects à l'entéroscanner. A propos de deux cas.

Two patients have been diagnosed preoperatively with ectopic pancreas located within the small bowel using CT-enteroclysis. This technique, combining helical CT and small bowel opacification through a naso-jejunal tube, allows detection of small tumors.