Experimental studies of the effectiveness of water distribution methods in a thin-layer sump were carried out on model and semi-industrial installations. When designing sedimentation tanks, it is usually recommended to take η = 0.03-0.07. According to our data, when η > 0.05, it is not possible to ensure uniform operation of all slots (holes), which worsens the hydrodynamic conditions in the settling zone. Experiments have also established that double gratings with a relative area of holes of 2n provide almost the same flow distribution as single gratings. In this case, the experimental values of β 1 were 2.6 and 2.7, respectively, i.e. differed by no more than 5%. With this in mind when installing double gratings with reflectors, the relative area holes with a sufficiently efficient flow distribution can be accepted and η = 0.06-0.1 instead of η = 0.03-0.05 recommended for single grates, which is essential to reduce the risk of clogging them and improve the reliability of sewer sedimentation tanks. The obtained dependences with sufficient accuracy for practice can be used to calculate double gratings and gratings with reflectors at values η=2η1 , where η1 is the relative area of the slots in a single grating, as well as when calculating partitions with round (square) holes, taking into obtained formulas bs = r holes, and ns = n holes.
The sedimentation process is of great importance in the purification of drinking water. To improve the efficiency of horizontal sedimentation tanks for drinking water treatment, it is recommended to use thin-layer sedimentation tanks. Experimental studies of the effectiveness of water distribution methods in a thin-layer sump were carried out on model and semi-industrial installations. The settling tank model was made of organic glass at a scale of 1:12. In accordance with the scale factor and the Froude criterion, Qo, tp, Vp were determined. An analysis of the research results showed that for all values of m, the closest approximation of Vph to Vr was achieved when the upper edges of the plates were located along a curve calculated using a method that considers the water flow in the distribution volume as a flow of variable mass. KOI at the same time exceeded 90%. It has been established that with a 3-4-fold increase in the hydraulic load of the sump with the proposed method of water distribution, its KOI decreases slightly (from 92-95% to 74-85%), while with the location of the upper edges of the plates along an inclined or horizontal straight line, the KOI decreases from 68-83% to 15-20%. For the conditions of production operation of sedimentation tanks, where, depending on the time of day, year and production technology, the amount of drinking water can vary widely, this circumstance is of particular importance. As a result, the efficiency of the drinking water treatment process will be increased.
Expansion of hemorrhoidal veins in children is a rather rare pathology. The authors conducted a comparative analysis of the clinical picture and treatment results of 46 children aged 1 to 18 years. The main causes of hemorrhoids were persistent constipation in 39,1% of patients, diarrhea in 21,7%, a two-stage act of defecation in 13%, sports overload in 13%, coughing attacks in 6.5%, and intense urination, due to urinary tract disorders – in 6,5% and others.
In the group of children under 3 years of age, conservative therapy was more effective in 70,2%, relapses were noted in 5,5% of children.
In 9 children (24,3%), the failure of conservative treatment was an indication for hemorrhoectomy. After surgical correction, relapses were not observed. The choice of treatment methods taking into account the age characteristics of children allowed the authors to get good results.
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