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Edoardo G Giannini - One of the best experts on this subject based on the ideXlab platform.
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Use of the platelet count/spleen Diameter Ratio for the noninvasive diagnosis of esophageal varices in patients with schistosomiasis.
Saudi Journal of Gastroenterology, 2011Co-Authors: Adnan Agha, Vincenzo Savarino, Mamdouh M Abdulhadi, S. Marenco, Abdelhaleem Bella, Dib Alsaudi, Ahmed El-haddad, Simona Inferrera, Edoardo G GianniniAbstract:Background/Aim: In patients with liver cirrhosis, the platelet count/spleen Diameter Ratio has been validated as a parameter for the noninvasive diagnosis of esophageal varices. Schistosoma infection is a frequent cause of portal hypertension in Middle Eastern countries, and is associated with the development of esophageal varices. In this study we aimed to evaluate the platelet count/spleen Diameter Ratio as a noninvasive tool for the prediction of the presence of esophageal varices in patients with schistosoma-related chronic liver disease. Patients and Methods: Forty-three patients with hepatosplenic schistosomiasis underwent upper digestive endoscopy to check for the presence of esophageal varices. Furthermore, all patients underwent abdominal ultrasonography, and maximum spleen Diameter (in mm) was measured. The platelet count/spleen Diameter Ratio was calculated in all patients. Results: Esophageal varices were found in 31 patients (72%). Age and gender were not significantly different between patients with and without varices. In patients with varices, median platelet count (82,000/μL versus 172,000/μL, P < 0.0001) and platelet count/spleen Diameter Ratio (571 versus 1651, P < 0.0001) were significantly lower, while spleen Diameter (147 mm versus 109 mm, P = 0.0006) was significantly larger. In multivariate analysis, the platelet count/spleen Diameter Ratio was the only parameter independently associated with the presence of varices (P < 0.0001). Conclusions: In this study we have validated the use of the platelet count/spleen Diameter Ratio for the noninvasive diagnosis of esophageal varices in patients with portal hypertension caused by schistosoma infection. In these patients, the platelet count/spleen Diameter Ratio might be used to allow better Rationalization of medical resources and use of endoscopy.
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external validation of the platelet count spleen Diameter Ratio for the diagnosis of esophageal varices in hepatitis c virus related cirrhosis
Digestive Diseases and Sciences, 2009Co-Authors: Adnan Agha, Eram Anwar, Kaukab Bashir, Vincenzo Savarino, Edoardo G GianniniAbstract:Background Screening for esophageal varices (EV) is an important part of the diagnostic workup of cirrhotic patients. Aims To independently validate the use of the platelet count/spleen Diameter Ratio for the non-invasive diagnosis of EV in patients with HCV-related cirrhosis and in a sub-group of patients with compensated disease. Methods A platelet count/spleen Diameter Ratio cut-off value of 909 was evaluated for the diagnosis of EV in the whole population (n = 311) and in patients with compensated disease alone (n = 114). Compensated disease was defined as the absence of ascites as detected by abdominal ultrasound in patients who are not on diuretics and absence of hepatic encephalopathy. Results In the whole cohort (EV prevalence 49.5%), the platelet count/spleen Diameter Ratio 909 cut-off value had 96.9% positive predictive value, 100% negative predictive value, and 98.4% efficiency for EV diagnosis. In compensated cirrhotics (EV prevalence 26.3%), the platelet count/spleen Diameter Ratio 909 cut-off showed an excellent negative predictive value (100%) and a positive predictive value of 93.8%. for the diagnosis of EV. Conclusions In patients with HCV-related cirrhosis, the platelet count/spleen Diameter may be proposed as a non-invasive tool for EV diagnosis, especially in financially deprived developing countries.
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platelet count spleen Diameter Ratio for the noninvasive diagnosis of esophageal varices results of a multicenter prospective validation study
The American Journal of Gastroenterology, 2006Co-Authors: Edoardo G Giannini, Atif Zaman, A Kreil, Annarosa Floreani, Pietro Dulbecco, Emanuela Testa, Roya Sohaey, Peter T Verhey, M Peckradosavljevic, C MansiAbstract:Platelet Count/Spleen Diameter Ratio for the Noninvasive Diagnosis of Esophageal Varices: Results of a Multicenter, Prospective, Validation Study
Keqing Shi - One of the best experts on this subject based on the ideXlab platform.
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performance of platelet count spleen Diameter Ratio for diagnosis of esophageal varices in cirrhosis a meta analysis
Digestive Diseases and Sciences, 2012Co-Authors: Li Ying, Xiao Lin, Zuoliu Xie, Keqing ShiAbstract:Background Platelet count/spleen Diameter Ratio (PSR) is a non-invasive method for the assessment of esophageal varices (EV), developed as an alternative to endoscopy.
A Saieed - One of the best experts on this subject based on the ideXlab platform.
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Effect of T-junction Diameter Ratio on stratified-wavy flow sepaRation
Journal of Natural Gas Science and Engineering, 2018Co-Authors: A Saieed, William Pao, Fakhruldin Mohd HashimAbstract:Abstract Most of the research carried out on reduced Diameter Ratio T-junctions concluded that partial phase sepaRation can be improved by decreasing the Diameter Ratio. Despite using very small Diameter Ratio T-junctions, petroleum industry has always faced the problem of continuous and sometimes very high liquid carryovers. In this regard, the sepaRation of air-water stratified-wavy flow in 1.0, 0.52, 0.67, 0.27 and 0.20 Diameter Ratio T-junctions was examined to investigate the effect of Diameter Ratio on phase sepaRation. Phase distribution of each T-junction was evaluated by observing the point at which liquid carryover starts (liquid carryover threshold) and the maximum liquid carryover delivered (peak liquid carryover). For optimum sepaRation it is essential that liquid carryover threshold is high and peak liquid carryover is low, however these parameters were found to decrease with the reduction in Diameter Ratio. It was observed that in stratified-wavy flow, the drop in liquid carryover threshold was reasonable and thus in this flow regime a decrease in Diameter Ratio was always found to enhance phase sepaRation. Two correlations were also developed to predict the phase splitting behavior, under a wide range of operating conditions.
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Experimental investigation on the effect of Diameter Ratio on two-phase slug flow sepaRation in a T-Junction
Journal of Petroleum Science and Engineering, 2018Co-Authors: A Saieed, William Pao, Buddhika N. Hewakandamby, Barry J. Azzopardi, David A. Wood, Hafiz Muhammad AliAbstract:Abstract T-junctions are often used in offshore platforms to partially separate gas from produced fluids. Poorly designed T-junctions frequently produce very high liquid (oil and/or water) carryovers, causing major issues to the downstream equipment train which is not designed to handle excessive liquid. This paper reports the liquid carryover experiments in T-junctions using five different side to main arm Diameter Ratios under slug flow regime. The obtained phase sepaRation curves can be divided into two component variables; liquid-carryover threshold and peak liquid carryover. The experiments demonstrate that with a decrease in Diameter Ratio both of these variables decrease. Yet, for superior multiphase flow sepaRation, a high liquid carryover threshold and a low peak liquid carryover are required. Hence, the generally accepted rule that a reduction in Diameter Ratio improves the phase sepaRation is revealed to be an over-extrapolated statement. The novel findings of this work are: 1) for optimum flow splitting under slug flow conditions, the Diameter Ratio should be kept between 1 and 0.67, while the Diameter Ratio 0.67 was found to be most suitable; 2) two correlations were developed for predicting two-phase slug flow sepaRation in different Diameter Ratio T-junctions. These correlations offer beneficial guidance and clarifications for a number of oil and gas flowline and pipeline applications.
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Numerical simulation of two-phase slug flow with liquid carryover in different Diameter Ratio T-junction
Journal of Physics: Conference Series, 2017Co-Authors: William Pao, L Hon, A Saieed, S BanAbstract:A smaller Diameter conduit pointing at 12 o'clock position is typically hot-tapped to a horizontal laying production header in offshore platform to tap produced gas for downstream process train. This geometric feature is commonly known as T-junction. The nature of multiphase fluid splitting at the T-junction is a major opeRational challenge due to unpredictable production environment. Often, excessive liquid carryover occurs in the T-junction, leading to complete platform trip and halt production. This is because the downstream process train is not designed to handle excessive liquid. The objective of this research is to quantify the effect of different Diameter Ratio on phase sepaRation efficiency in T-junction. The liquid carryover is modelled as two-phase air-water flow using Eulerian Mixture Model coupled with Volume of Fluid Method to mimic the slug flow in the main pipe. The focus in this paper is 0.0254 m (1 inch) Diameter horizontal main arm and vertical branch arm with Diameter Ratio of 1.0, 0.5 and 0.3. The present research narrowed the investigation to only slug flow regime using Baker's map as reference. The investigation found that, contrary to common believe, smaller Diameter Ratio T-junction perform worse than larger Diameter Ratio T-junction.
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Numerical simulation of two–phase sepaRation in a small Diameter Ratio T‐junction
Materialwissenschaft und Werkstofftechnik, 2017Co-Authors: William Pao, A Saieed, Fakhruldin Mohd Hashim, Rohaizad B. M. NorpiahAbstract:The utilization of T-junctions for flow division is quite common in industries. Due to the phenomena known as multiphase maldistribution, occurring in a T-junction, they are often used as partial phase separators for reducing the work load on phase sepaRation devices in oil and gas platforms. Previous literature says that reducing the Diameter Ratio of the T-junction improves the two-phase sepaRation, however it was also reported that reducing the Diameter Ratio too much has a negative effect on two-phase sepaRation. To test this, a numerical study was performed to see the two-phase stratified flow sepaRation in 1, 0.6 and 0.167 Diameter Ratio T-junctions. Furthermore, the impact of air superficial velocity on phase maldistribution at the junction is also considered. The T-junctions with Diameter Ratios 1 and 0.6 were just used for the validation of present model, by comparing the obtained numerical results with previous experimental data. While, 0.167 Diameter Ratio T-junction is the one for which the actual analysis was performed. It is concluded that an increase in air superficial velocity aids liquid carryover, whereas liquid carryover is very sensitive to side arm extraction rates in a very small Diameter Ratio T-junction.
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numerical study of gas liquid flow maldistribution in a t junction having very small Diameter Ratio
2017 3rd International Conference on Power Generation Systems and Renewable Energy Technologies (PGSRET), 2017Co-Authors: A Saieed, Fakhruldin Mohd Hashim, Rohaizad B. M. NorpiahAbstract:Industries have been using T-junctions for either combining or dividing incoming fluids for decades. A flow phenomena termed as phase maldistribution have caused oil and gas industries to use T-junctions as partial multiphase separators. This is because, a T-junction can reduce the load on main separators by partly separating the gas from the multiphase flow coming from an oil well. From the previously published research, it was found that liquid phase superficial velocity have an inverse relationship with liquid carryover. However, to the best of author's knowledge, all of these investigations were focused on T- junctions with Diameter Ratios between 1 and 0.2. Likewise, most of these studies were performed on fully horizontal T-junctions. Previous literature also states that decreasing the Diameter Ratio increases the phase sepaRation performance of a T-junction. However, a couple of sources reported that in very small Diameter Ratio T-junctions, liquid carryover becomes very sensitive to side arm extraction rates. This ultimately cause liquid carryover to suddenly increase at high extraction rates. Therefore, a numerical study is carried out in order to understand the effect of liquid superficial velocity on liquid carryover in a 0.167 Diameter Ratio T-junction having a vertically upward side. For this study, simulations were performed on 1 and 0.167 Diameter Ratio T- junctions under air-water stratified flow conditions. Results from 1 Diameter Ratio T-junctions were used to validate present model by comparing it with previously reported experimental data. The results obtained from 0.167 Diameter Ratio T-junction depicts that higher the liquid phase velocity, less will be the liquid carryover. However, liquid carryover is relatively quite large in 0.167 Diameter Ratio T-junction as compare to 1 Diameter Ratio T- junction under stratified flow conditions.
William Pao - One of the best experts on this subject based on the ideXlab platform.
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Effect of T-junction Diameter Ratio on stratified-wavy flow sepaRation
Journal of Natural Gas Science and Engineering, 2018Co-Authors: A Saieed, William Pao, Fakhruldin Mohd HashimAbstract:Abstract Most of the research carried out on reduced Diameter Ratio T-junctions concluded that partial phase sepaRation can be improved by decreasing the Diameter Ratio. Despite using very small Diameter Ratio T-junctions, petroleum industry has always faced the problem of continuous and sometimes very high liquid carryovers. In this regard, the sepaRation of air-water stratified-wavy flow in 1.0, 0.52, 0.67, 0.27 and 0.20 Diameter Ratio T-junctions was examined to investigate the effect of Diameter Ratio on phase sepaRation. Phase distribution of each T-junction was evaluated by observing the point at which liquid carryover starts (liquid carryover threshold) and the maximum liquid carryover delivered (peak liquid carryover). For optimum sepaRation it is essential that liquid carryover threshold is high and peak liquid carryover is low, however these parameters were found to decrease with the reduction in Diameter Ratio. It was observed that in stratified-wavy flow, the drop in liquid carryover threshold was reasonable and thus in this flow regime a decrease in Diameter Ratio was always found to enhance phase sepaRation. Two correlations were also developed to predict the phase splitting behavior, under a wide range of operating conditions.
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Experimental investigation on the effect of Diameter Ratio on two-phase slug flow sepaRation in a T-Junction
Journal of Petroleum Science and Engineering, 2018Co-Authors: A Saieed, William Pao, Buddhika N. Hewakandamby, Barry J. Azzopardi, David A. Wood, Hafiz Muhammad AliAbstract:Abstract T-junctions are often used in offshore platforms to partially separate gas from produced fluids. Poorly designed T-junctions frequently produce very high liquid (oil and/or water) carryovers, causing major issues to the downstream equipment train which is not designed to handle excessive liquid. This paper reports the liquid carryover experiments in T-junctions using five different side to main arm Diameter Ratios under slug flow regime. The obtained phase sepaRation curves can be divided into two component variables; liquid-carryover threshold and peak liquid carryover. The experiments demonstrate that with a decrease in Diameter Ratio both of these variables decrease. Yet, for superior multiphase flow sepaRation, a high liquid carryover threshold and a low peak liquid carryover are required. Hence, the generally accepted rule that a reduction in Diameter Ratio improves the phase sepaRation is revealed to be an over-extrapolated statement. The novel findings of this work are: 1) for optimum flow splitting under slug flow conditions, the Diameter Ratio should be kept between 1 and 0.67, while the Diameter Ratio 0.67 was found to be most suitable; 2) two correlations were developed for predicting two-phase slug flow sepaRation in different Diameter Ratio T-junctions. These correlations offer beneficial guidance and clarifications for a number of oil and gas flowline and pipeline applications.
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Numerical simulation of two-phase slug flow with liquid carryover in different Diameter Ratio T-junction
Journal of Physics: Conference Series, 2017Co-Authors: William Pao, L Hon, A Saieed, S BanAbstract:A smaller Diameter conduit pointing at 12 o'clock position is typically hot-tapped to a horizontal laying production header in offshore platform to tap produced gas for downstream process train. This geometric feature is commonly known as T-junction. The nature of multiphase fluid splitting at the T-junction is a major opeRational challenge due to unpredictable production environment. Often, excessive liquid carryover occurs in the T-junction, leading to complete platform trip and halt production. This is because the downstream process train is not designed to handle excessive liquid. The objective of this research is to quantify the effect of different Diameter Ratio on phase sepaRation efficiency in T-junction. The liquid carryover is modelled as two-phase air-water flow using Eulerian Mixture Model coupled with Volume of Fluid Method to mimic the slug flow in the main pipe. The focus in this paper is 0.0254 m (1 inch) Diameter horizontal main arm and vertical branch arm with Diameter Ratio of 1.0, 0.5 and 0.3. The present research narrowed the investigation to only slug flow regime using Baker's map as reference. The investigation found that, contrary to common believe, smaller Diameter Ratio T-junction perform worse than larger Diameter Ratio T-junction.
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Numerical simulation of two–phase sepaRation in a small Diameter Ratio T‐junction
Materialwissenschaft und Werkstofftechnik, 2017Co-Authors: William Pao, A Saieed, Fakhruldin Mohd Hashim, Rohaizad B. M. NorpiahAbstract:The utilization of T-junctions for flow division is quite common in industries. Due to the phenomena known as multiphase maldistribution, occurring in a T-junction, they are often used as partial phase separators for reducing the work load on phase sepaRation devices in oil and gas platforms. Previous literature says that reducing the Diameter Ratio of the T-junction improves the two-phase sepaRation, however it was also reported that reducing the Diameter Ratio too much has a negative effect on two-phase sepaRation. To test this, a numerical study was performed to see the two-phase stratified flow sepaRation in 1, 0.6 and 0.167 Diameter Ratio T-junctions. Furthermore, the impact of air superficial velocity on phase maldistribution at the junction is also considered. The T-junctions with Diameter Ratios 1 and 0.6 were just used for the validation of present model, by comparing the obtained numerical results with previous experimental data. While, 0.167 Diameter Ratio T-junction is the one for which the actual analysis was performed. It is concluded that an increase in air superficial velocity aids liquid carryover, whereas liquid carryover is very sensitive to side arm extraction rates in a very small Diameter Ratio T-junction.
Rohaizad B. M. Norpiah - One of the best experts on this subject based on the ideXlab platform.
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Numerical simulation of two–phase sepaRation in a small Diameter Ratio T‐junction
Materialwissenschaft und Werkstofftechnik, 2017Co-Authors: William Pao, A Saieed, Fakhruldin Mohd Hashim, Rohaizad B. M. NorpiahAbstract:The utilization of T-junctions for flow division is quite common in industries. Due to the phenomena known as multiphase maldistribution, occurring in a T-junction, they are often used as partial phase separators for reducing the work load on phase sepaRation devices in oil and gas platforms. Previous literature says that reducing the Diameter Ratio of the T-junction improves the two-phase sepaRation, however it was also reported that reducing the Diameter Ratio too much has a negative effect on two-phase sepaRation. To test this, a numerical study was performed to see the two-phase stratified flow sepaRation in 1, 0.6 and 0.167 Diameter Ratio T-junctions. Furthermore, the impact of air superficial velocity on phase maldistribution at the junction is also considered. The T-junctions with Diameter Ratios 1 and 0.6 were just used for the validation of present model, by comparing the obtained numerical results with previous experimental data. While, 0.167 Diameter Ratio T-junction is the one for which the actual analysis was performed. It is concluded that an increase in air superficial velocity aids liquid carryover, whereas liquid carryover is very sensitive to side arm extraction rates in a very small Diameter Ratio T-junction.
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numerical study of gas liquid flow maldistribution in a t junction having very small Diameter Ratio
2017 3rd International Conference on Power Generation Systems and Renewable Energy Technologies (PGSRET), 2017Co-Authors: A Saieed, Fakhruldin Mohd Hashim, Rohaizad B. M. NorpiahAbstract:Industries have been using T-junctions for either combining or dividing incoming fluids for decades. A flow phenomena termed as phase maldistribution have caused oil and gas industries to use T-junctions as partial multiphase separators. This is because, a T-junction can reduce the load on main separators by partly separating the gas from the multiphase flow coming from an oil well. From the previously published research, it was found that liquid phase superficial velocity have an inverse relationship with liquid carryover. However, to the best of author's knowledge, all of these investigations were focused on T- junctions with Diameter Ratios between 1 and 0.2. Likewise, most of these studies were performed on fully horizontal T-junctions. Previous literature also states that decreasing the Diameter Ratio increases the phase sepaRation performance of a T-junction. However, a couple of sources reported that in very small Diameter Ratio T-junctions, liquid carryover becomes very sensitive to side arm extraction rates. This ultimately cause liquid carryover to suddenly increase at high extraction rates. Therefore, a numerical study is carried out in order to understand the effect of liquid superficial velocity on liquid carryover in a 0.167 Diameter Ratio T-junction having a vertically upward side. For this study, simulations were performed on 1 and 0.167 Diameter Ratio T- junctions under air-water stratified flow conditions. Results from 1 Diameter Ratio T-junctions were used to validate present model by comparing it with previously reported experimental data. The results obtained from 0.167 Diameter Ratio T-junction depicts that higher the liquid phase velocity, less will be the liquid carryover. However, liquid carryover is relatively quite large in 0.167 Diameter Ratio T-junction as compare to 1 Diameter Ratio T- junction under stratified flow conditions.