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Biomedical subjects

C Modica

Publications and source records attributed to C Modica.

8 recordsLinked to original sources
PubMed2005

Experimental analysis of the hydrass flushing gate and field validation of flush propagation modelling.

As well known, a periodical cleansing of sewers results necessary in order to avoid or reduce many unpleasant consequences due to the presence of sediments, such as the solid re-suspension during rain events and the reduction of the channel flow capacity. For this purpose, different systems based on flushing techniques have been adopted in sewers. In the present paper, the results of an analysis of the hydraulics of a flushing device, the Hydrass gate, is presented. In particular, an experimental investigation on a scale model under steady conditions was carried out in order to determine the behaviour of the device during the flushing phase. Outflow relations were derived for the different outflow conditions. A numerical model was finally set up for testing the relations under unsteady conditions, using for validation the experimental data of a previous measurement campaign carried out in a sewer reach of the city of Lyon, France.

Models, Theoretical↗
PubMed2003

Flow velocities and shear stresses during flushing operations in sewer collectors.

Many relevant problems of drainage systems such as first flush pollution, flow capacity reduction and consequent risks of surcharges are worsened by sediment accumulation in sewer collectors. For the solution of these problems several sediment cleansing methods and techniques, e.g. mechanical methods, traps and flushing devices, have been developed and applied in the last decades. In particular, simulation studies and experimental campaigns have shown the effectiveness of flushing methods as preventive cleansing strategy in sewer collectors. In this paper the results of a numerical investigation for determining flushing waves characteristics both in terms of duration and flow rate are presented. The collector section lengths where flow velocities and average shear stresses determined by flushing waves exceed minimum threshold values are evaluated using a dimensionless approach. The results, related to the operative ranges of the practical applications, are exposed by means of graphs and regressive equations.

Geologic Sediments↗
PubMed2003

Two-vector mechanics.

The conventional orthodontic appliance is not without its limitations for certain types of tooth movements; in particular, if the appliance cannot access the area to elicit the type of force vector for a particular displacement. Examples of such movements are: space closure by translation, uprighting and intrusion of posterior teeth, intrusion with retraction and lingual root torque of anterior teeth. In this paper we describe a mathematical method to design an appliance system that overcomes these difficulties. This system includes two statically determined elements and allows for highly controlled force vector application point and direction. A clinical case of midline discrepancy is shown to demonstrate the clinical use and utility of this method.

Biomechanical Phenomena↗
PubMed2002

PID and PLC units for the real-time control of sewer systems.

Moveable gates for the real-time control (RTC) of sewer systems storage capacities are usually operated by controllers which, on the basis of local water level or flow velocity measurements, calculate the regulation errors of the monitored variables, determining the necessary regulator movements to lead the flow conditions to the desired set point. In this paper the results of an investigation on the influence of proportional-integral-derivative (PID) controllers and programmable logic controllers (PLC) for the RTC of moveable sluice gates positioned into sewer systems are presented. The analysis of response time, damping and regulation errors provided information on the PID parameter calibration values and on the PLC control function performances. A comparison between the two kind of controllers has also been carried out.

Automation↗
PubMed2000

The design of custom orthodontic mechanics.

The straightwire appliance promises prescribed tooth positions within the arches. Unfortunately, such an outcome is not necessarily achieved, especially in the adult patient. Teeth do not always move according to a template. Continuous archwires do not allow for differentiation between active and reactive units; consequently, the correct force system is never developed. These shortcomings could be overcome by custom-designed mechanics. Here we report on the use of Dental Movement Analysis (DMA) software supported by two clinical examples. On the computerized occlusogram, DMA stimulates the desired tooth movements and computes the force vectors and moments necessary to achieve the planned result. These images enable the clinician to fabricate a custom appliance for maximum efficiency. Maximum efficiency results in minimal treatment time.

Journal Article↗
PubMed1999

Applying HEDIS clinical measures to community health centers: a feasibility study.

Since participation in managed care is critical for community health centers' (CHCs) survival, centers must demonstrate their good performance to purchasers (e.g., state Medicaid agencies) and health plans. Such measures also can contribute to quality improvement. Ideally, the effort would use measures and methods widely recognized in the managed care industry, logically the Health Plan Employer Data and Information Set (HEDIS). This article summarizes a feasibility study of applying HEDIS clinical measures to CHCs as providers. It finds that, with concerted, well-directed efforts, it will be possible to use clinical HEDIS measures in health centers.

Community Health Centers↗
PubMed1999

[Discovery of a focus of intestinal bilharziasis in te Republic of Djibouti].

An unprecedented pocket of intestinal schistosomiasis was discovered in the Republic of Djibouti in 1997. The first cases were diagnosed in French and Djiboutian tourists who presented initial symptoms of bilharzian infection after bathing in the fresh-water basin under Hassan Gari Bira Falls, near Randa. Seventeen cases were subsequently confirmed by detection of anti-schistosome antibodies using indirect hemagglutination (IH) and indirect immunofluorescence (IIF) and/or detection of Schistosoma mansoni eggs in the stool. Further testing was performed in 35 village inhabitants, mostly children, who had been exposed by bathing in the basin. The IH reaction was positive in 28 patients (80 p. 100) including 17 (49 p. 100) with levels greater than 1/64. In 92 p. 100 of cases, IH findings were confirmed by IIF which indicated that association with hypereosinophilia was common. Schistosoma mansoni eggs were found in stools from 7 patients (19 p. 100) who generally displayed mild hypereosinophilia. Information concerning the zone of risk was distributed and control measures were undertaken as widely as possible in Djibouti and abroad.

Adolescent↗