Determination of vorticity, gradients of flow parameters and curvature of stream-lines behind unsteady curved shock waves

1966 ◽  
Vol 15 (3) ◽  
pp. 365-379
Author(s):  
Rishi Ram ◽  
R. S. Mishra
Keyword(s):  
Shock Waves ◽  
Flow Parameters ◽  
Curved Shock Waves ◽  
Stream Lines

Use of non-contrast computed tomography determined urinary stone fragility in predicting the outcome of extracorporeal shockwave lithotripsy treatment: a single-center study

2020 ◽  
Vol 14 (2) ◽  
pp. 59-63
Author(s):  
Athar Hameed ◽  
Khazir Hayyat Gondal
Keyword(s):  
Shock Waves ◽  
Renal Stone ◽  
Plain Film ◽  
Renal Stones ◽  
Renal Calculus ◽  
Urinary Stone ◽  
Stone Disease ◽  
Urinary Stones ◽  
Fisher Exact Test

Background: Renal stones represent a common urological pathology where standard treatment advised is ESWL in current practice. However, NCCT based determination of stone fragility may help to predict the outcome of ESWL treatment, hence optimizing its clinical use. Therefore, this study evaluated the role of NCCT determined urinary stone fragility in predicting the outcome of ESWL treatment in local clinical settings. Patients and methods: One hundred patients with single renal calculus of 0.6-2 cm in size were included. NCCT based determination of stone fragility in HU units was done for all patients. Patients were then subjected to ESWL, with a maximum of 3000 shock waves given per ESWL session. Plain film and/or ultrasonography was used to monitor ESWL treatment progress with a final NCCT evaluation at 12 weeks to determine the clearance of the calculi for each patient. Association of NCCT based stone fragility and outcome of ESWL was statistically analyzed using Fisher exact test. Results: The mean age of the patients was 37.7 ± 10.9 years with 54% being male. Decreasing stone fragility on NCCT (high = <500HU, moderate = 500-1000HU, and high = 1000HU) required more number and intensity of ESWL sessions (1-2 visits and 3000-6000 shock waves for high stone fragility group, 3-5 visits and 7000-18000 shock waves for the moderate group, and 6 visits and >18000 shock waves for low fragility group, respectively) necessary for clearance of urinary stones (p<0.001). In 98% of patients, the clearance of urinary stones was excellent. Conclusion: Renal stone patients with NCCT determined high and moderate stone fragility show an optimal response after ESWL treatment, whereas, for low fragility renal stones attenuative treatment like percutaneous nephrolithotomy and/or ureteroscopy should be considered instead of ESWL. This approach can enable patient stratification before ESWL therapy ensuring better clinical management of the renal stone disease.

Determination of Discharge Coefficient for Ball Valves With Calibrated Inserts

2004 ◽  
Author(s):  
Gino James Rouss ◽  
William S. Janna
Keyword(s):  
Discharge Coefficient ◽  
Polynomial Equation ◽  
The Body ◽  
Orifice Diameter ◽  
Flow Parameters ◽  
Dimensionless Groups ◽  
Order Polynomial ◽  
Experimental Process ◽  
Power Law Equation

The valve coefficient was measured for 1, 1-1/4, 1-1/2 and 2 nominal ball valves. A recently designed orifice insert was used with these valves to obtain smaller valve coefficients. Orifice inserts were threaded into the body of a ball valve just upstream of the ball itself. The valve coefficient was measured for every insert used with these valves, and an expression was determined to relate the orifice diameter to other pertinent flow parameters. Two dimensionless groups were chosen to correlate the collected data, and expressions were developed that can be used as aids in sizing the orifice insert needed to obtain the desired valve coefficient. The study has shown that a 2nd order polynomial equation as well as a power law equation can both be used to predict the desired results. Knowing pipe size and schedule, the diameter of the orifice insert needed to obtain the required valve coefficient can be approximated with minimum error. An error analysis performed on the collected data shows that the results are highly accurate, and that the experimental process is repeatable.

Development And Testing Of Combined germicidal Recirculator

2021 ◽  
pp. 43-49
Author(s):  
Igor M. Dovlatov ◽  
Leonid Yu. Yuferev ◽  
Svetlana A. Mikaeva ◽  
Angela S. Mikaeva ◽  
Olga E. Zheleznikova
Keyword(s):  
Exposure Time ◽  
Flow Direction ◽  
Air Flow ◽  
Live Weight ◽  
Experimental Comparison ◽  
Disinfection Methods ◽  
Flow Parameters ◽  
Poultry Facilities ◽  
Air Disinfection

The important problem of the poultry farming is the prevention of infectious diseases causing poultry deaths and unplanned financial losses. The article authors represent an overview of the air disinfection methods and the selection criteria for the disinfection methods being the most effective among other methods applicable for poultry facilities. There were determined the main factors influencing the germicidal efficiency of the ultraviolet (UV) irradiance sources. Studies were considered, where influence on the germicidal efficiency was discussed in terms of the UV irradiation exposure time in poultry facilities with floor conditions. The theoretical parameters substantiation is given for the device combining the two main disinfection components; it is done by development of both the mathematical model for the average irradiance rate calculation and the calculation method of the highspeed air flow parameters. Also, the method has been developed for determination of the needed number of the combined germicidal aerosol units in poultry keeping premises. The authors present the results of the experiments conducted for determination of the germicidal efficiency of the disinfection fulfilled against such microorganisms as Coli bacteria, Kochii bacilli, etc. with use of the developed combined recirculator. The experimental comparison with a prototype was carried out for the decontamination efficiency achieved with aid of the newly developed combined germicidal aerosol recirculator used in the following mode: the exposure time made 1 hour of work, then 2 hours of break on condition of the process cycling throughout the entire daylight hours. Here presented is the recommended layout of a number of the combined germicidal aerosol units in box-type rooms with poultry keeping on floor in a case of the ideal air flow direction. The increase by 20 % was found in the disinfection efficiency as well as the growth by 7 % in the additional live weight gain of the poultry.

scholarly journals Application of electrical capacitance tomography and artificial neural networks to rapid estimation of cylindrical shape parameters of industrial flow structure

2016 ◽  
Vol 65 (4) ◽  
pp. 657-669 ◽  
Author(s):  
Hela Garbaa ◽  
Lidia Jackowska-Strumiłło ◽  
Krzysztof Grudzień ◽  
Andrzej Romanowski
Keyword(s):  
Electrical Capacitance Tomography ◽  
Cylindrical Shape ◽  
Electrical Capacitance ◽  
Flow Monitoring ◽  
Flow Parameters ◽  
Classic Approach ◽  
Artificial Neural ◽  
Funnel Flow ◽  
Capacitance Tomography

Abstract A new approach to solve the inverse problem in electrical capacitance tomography is presented. The proposed method is based on an artificial neural network to estimate three different parameters of a circular object present inside a pipeline, i.e. radius and 2D position coordinates. This information allows the estimation of the distribution of material inside a pipe and determination of the characteristic parameters of a range of flows, which are characterised by a circular objects emerging within a cross section such as funnel flow in a silo gravitational discharging process. The main advantages of the proposed approach are explicitly: the desired characteristic flow parameters are estimated directly from the measured capacitances and rapidity, which in turn is crucial for online flow monitoring. In a classic approach in order to obtain these parameters in the first step the image is reconstructed and then the parameters are estimated with the use of image processing methods. The obtained results showed significant reduction of computations time in comparison to the iterative LBP or Levenberg-Marquard algorithms.

Determination of Discharge Coefficient for Ball Valves With Calibrated Inserts

2003 ◽  
Author(s):  
Gino James Rouss ◽  
William S. Janna
Keyword(s):  
Discharge Coefficient ◽  
Ball Valve ◽  
The Body ◽  
Orifice Diameter ◽  
Control Element ◽  
Flow Parameters ◽  
Experimental Process ◽  
Power Law Equation ◽  
Two Parameter

The valve coefficient was measured for 1/2-, 3/4- and 1 nominal ball valves. It was desired to use a recently designed orifice insert with these valves to obtain smaller valve coefficients. Orifice inserts were placed into the body of a threaded ball valve just upstream of the spherical control element. The valve coefficient was measured for each insert, and an expression was determined to relate the orifice diameter to other pertinent flow parameters. Two groups were chosen to correlate the collected data, and a graph was developed. These results can be used as an aid in sizing the orifice insert needed to obtain the desired valve coefficient. The study has shown that a two parameter power law equation can be used as an aid in predicting the desired results. Knowing pipe size and schedule, the diameter of the orifice insert needed to obtain the desired valve coefficient can be approximated with minimum error. An error analysis performed on the collected data shows that the results are highly accurate, and that the experimental process is repeatable.

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