scholarly journals A Mathematical Model for Forecasting the Dam-Break Flood Routing Process of a Landslide Dam

2012 ◽  
Vol 2012 ◽  
pp. 1-16 ◽  
Author(s):  
Fugang Xu ◽  
Hongwei Zhou ◽  
Jiawen Zhou ◽  
Xingguo Yang

Once a landslide dam bursts, its reservoir discharges quickly in a flood which will cause catastrophic damage to life and property downstream. For a specific landslide dam, the peak flow rate and the evolution of downstream flood are influenced by the shape and size of the dike breach when dam-break occurs. According to the general nature of landslide dams and field observations of dike-breach development patterns, a dike-breach propagation mode has been determined. By combining an improved empirical equation with knowledge of the dike-breach propagation mode, a mathematical model for forecasting dam-break flood routing has been developed and is presented here. Sensitivity analysis was then carried out based on the computed results for peak flow rate and the flood evolution curve under different parameters. The computed results showed that the width coefficient and the depth coefficient had similar effects on the dam-break flood but that the impact of the depth coefficient was more significant than that of the width coefficient. Finally, the proposed model was used to calculate the flood evolution for the Tangjiashan landslide dam. The computed results showed that the error between the simulated result and the measured data was less than 5%.

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Babatunde K. Hamza ◽  
Muhammed Ahmed ◽  
Ahmad Bello ◽  
Musliu Adetola Tolani ◽  
Mudi Awaisu ◽  
...  

Abstract Background Benign prostate hyperplasia (BPH) is characterized by an increase in the number of epithelial and stromal cells in the periurethral area of the prostate. Lower urinary tract symptoms (LUTS) often develop as a manifestation of bladder outlet obstruction (BOO) due to benign prostate enlargement. When the prostate enlarges, protrusion into the bladder often occurs as a result of morphological changes of the gland. Prostatic protrusion into the bladder can be measured with ultrasound as intravesical prostatic protrusion (IPP). There are studies that have shown IPP as a reliable predictor of bladder obstruction index (BOOI) as measured by pressure flow studies. IPP is thereby reliable in assessing the severity of BOO in patients with BPH. The severity of symptoms in patients with BPH can be assessed through several scoring systems. The most widely used symptoms scoring system is the International Prostate Symptoms Score (IPSS). The aim of this study is to determine the correlation of IPP with IPSS in men with BPH at our facility. Methods The study was a cross-sectional observational study that was conducted at the Division of Urology, Department of Surgery, in our facility. The study was conducted on patients greater than 50 years LUTS and an enlarged prostate on digital rectal examination and/or ultrasound. All consenting patients were assessed with the International Prostate Symptoms Score (IPSS) questionnaire, following which an abdominal ultrasound was done to measure the intravesical prostatic protrusion (IPP), prostate volume (PV) and post-void residual (PVR) urine. All the patients had uroflowmetry, and the peak flow rate was determined. The data obtained were entered into a proforma. The results were analyzed using Statistical Package for Social Sciences (SPSS) software package version 20. Results A total of 167 patients were seen during the study period. The mean age was 63.7 ± 8.9 years, with a range of 45–90 years. The mean IPSS was 18.24 ± 6.93, with a range of 5–35. There were severe symptoms in 49.1%, while 43.1% had moderate symptoms and 7.8% had mild symptoms. The overall mean IPP was 10.3 ± 8 mm. Sixty-two patients (37.1%) had grade I IPP, 21 patients (12.6%) had grade II IPP and 84 patients (50.3%) had grade III IPP. The mean prostate volume and peak flow rate were 64 g ± 34.7 and 11.6 ml/s ± 5.4, respectively. The median PVR was 45 ml with a range of 0–400 ml. There was a significant positive correlation between the IPP and IPSS (P = 0.001). IPP also had a significant positive correlation with prostate volume and post-void residual and a significant negative correlation with the peak flow rate (P < 0.01). Conclusion Intravesical prostatic protrusion is a reliable predictor of severity of LUTS as measured by IPSS, and it also shows good correlation with other surrogates of bladder outlet obstruction.


Resuscitation ◽  
2003 ◽  
Vol 57 (2) ◽  
pp. 193-199 ◽  
Author(s):  
Horst G. Wagner-Berger ◽  
Volker Wenzel ◽  
Angelika Stallinger ◽  
Wolfgang G. Voelckel ◽  
Klaus Rheinberger ◽  
...  

1990 ◽  
pp. 125-129
Author(s):  
Motoaki Sugawara ◽  
Akio Hirai ◽  
Yasutsugu Seo ◽  
Yasuo Miyajima ◽  
Takanobu Uchibori

Thorax ◽  
1984 ◽  
Vol 39 (11) ◽  
pp. 828-832 ◽  
Author(s):  
K M Venables ◽  
P S Burge ◽  
A G Davison ◽  
A J Newman Taylor
Keyword(s):  

Thorax ◽  
1979 ◽  
Vol 34 (3) ◽  
pp. 308-316 ◽  
Author(s):  
P S Burge ◽  
I M O'Brien ◽  
M G Harries

2010 ◽  
Vol 19 (3) ◽  
pp. 278-284 ◽  
Author(s):  
Linda Y. Y. Chan ◽  
Alice Y. M. Jones ◽  
Raymond C. K. Chung ◽  
K. N. Hung

Background An accurate predictor of successful decannulation in neurosurgical patients that indicates the best time for tracheotomy decannulation would minimize the risks of continued cannulation and unsuccessful decannulation. Objective To determine whether the peak flow rate during induced cough is an appropriate predictor of successful decannulation. Methods A total of 32 neurosurgical patients with a tracheotomy were enrolled. The highest peak expiratory flow rate during 3 induced coughs, the total volume of tracheal secretions collected in 6 hours, and scores on the Glasgow Coma Scale were recorded. Logistic regression analysis was applied to determine the relationship between these variables and successful decannulation (reintubation not required within 72 hours). Results Decannulation was attempted in 23 of 32 patients. The remaining 9 patients were considered clinically inappropriate for the procedure. Of the 23 patients decannulated, 2 required reinsertion of the tracheotomy tube. Analysis revealed that peak flow rate during induced cough (odds ratio, 1.12; 95% confidence interval, 1.02–1.23) was independently associated with successful decannulation (accuracy, 75%; sensitivity, 85.7%; specificity, 54.5%). The receiver operating characteristic curve indicated an optimal cutoff point of 29 L/min. Conclusion Measurement of peak flow rate during induced cough is a simple and reproducible intervention that improves predictability of successful decannulation in patients with tracheotomy.


1971 ◽  
Vol 13 (2) ◽  
pp. 353-356 ◽  
Author(s):  
M. E. Castle ◽  
R. Henderson

SUMMARYRecords of milking rate, milk yield and milk composition were collected over 12 yr from 123 Ayrshire heifers in their first lactation in one herd. Three direct measures of milking rate, i.e. peak flow rate, machine rate and overall rate were closely correlated and each was also correlated with total lactation yield of milk. Milking rate accounted for only a very small part of the variation in fat and total solids percentages. The mean yield of milk per milking in early lactation was a better predictor of total lactation yield than was milking rate but, among animals giving the same early lactation yield of milk, the faster milkers gave higher lactation yields than the slower milkers.


Open Heart ◽  
2014 ◽  
Vol 1 (1) ◽  
pp. e000164 ◽  
Author(s):  
Tim C Clayton ◽  
Tom W Meade ◽  
Elizabeth L Turner ◽  
Bianca L De Stavola

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