In crude oil transportation, adhesion of oil on pipe wall can cause partial or total blockage of the pipe. This process is significantly affected by wall sticking occurrence temperature(WSOT). In this work, an efficie...In crude oil transportation, adhesion of oil on pipe wall can cause partial or total blockage of the pipe. This process is significantly affected by wall sticking occurrence temperature(WSOT). In this work, an efficient approach for estimating WSOT of high water-cut oil, which can agree well with the actual environment of multiphase transportation pipeline, is proposed. Based on the energy dissipation theory, it is possible to make comparison of average shear rates between the stirred vessel and the flow loop. The impacts of water content and shear rate on WSOT are investigated using the stirred vessel and the flow loop. Good agreement has been observed between the stirred vessel and the flow loop results with the maximum and the average absolute deviations equating to 3.30 °C and 2.18 °C, respectively. The development of gathering scheme can enjoy some benefits from this method.展开更多
To study the wall-sticking phenomenon and prevent pipeline blockage accidents,two analytical methods are used to evaluate the influence of different crude oil components on the wall-sticking occurrence temperature(WSO...To study the wall-sticking phenomenon and prevent pipeline blockage accidents,two analytical methods are used to evaluate the influence of different crude oil components on the wall-sticking occurrence temperature(WSOT).The WSOT and the interactions among oil,water,and surface solids are measured and calculated by various devices under different values of the wax content,water pH,and salinity.The results show that there is greater correlation between the wax content and WSOT than between resins/asphaltenes and WSOT.Furthermore,the wax content,water pH,and salinity have different effects on WSOT.There is generally a positive correlation between wax content and WSOT,whereas the maximum WSOT occurs when the water pH is in the range 5.7–6.5,and decreases under more acidic or alkaline conditions.As the salinity increases,WSOT decreases slightly,but quickly becomes saturated.In terms of interactions,variations in the interfacial tension and adhesion work with pH and salinity are consistent with that of WSOT,while the contact angle exhibits the opposite relation.展开更多
目的探讨临床对不同级别前列腺癌鉴别诊断中行磁共振弥散加权成像(diffusion-weighted imaging,DWI)纹理特征分析的价值。方法选取2018年9月至2023年3月中山大学附属第七医院就诊的前列腺癌患者作为调查对象,病例数量共60例。全体患者...目的探讨临床对不同级别前列腺癌鉴别诊断中行磁共振弥散加权成像(diffusion-weighted imaging,DWI)纹理特征分析的价值。方法选取2018年9月至2023年3月中山大学附属第七医院就诊的前列腺癌患者作为调查对象,病例数量共60例。全体患者均通过手术或穿刺活检病理检查得到证实,术前接受磁共振扫查,由医师借助ITK-SNAP软件手动在DWI上描画出感兴趣区(region of interest,ROI),并使用AK软件获得412个纹理特征,观察筛选在低危(n=15)和高危(n=45)前列腺癌患者中具有明显差异的纹理特征。采用受试者工作特征(receiver operating characteristics,ROC)曲线对各项参数诊断效能作出评估,并建立随机森林(random forest,RF)分类器,通过ROC曲线对模型诊断效能作出评价,最后通过交叉验证方法对模型鲁棒性进行验证。结果通过筛选后共获得了12个纹理特征,在建立的模型中,对低危和高危前列腺癌进行鉴别的ROC的曲线下面积(the area under the ROC curve,AUC)为0.96,准确性、灵敏度、特异度分别为99.07%、100%、98.12%,其中GLCMEnergyangle45offset1是该模型中最为重要的纹理特征参数。从交叉验证结果可知,本研究所建立模型的精确度、灵敏度、特异度分别为78.09%、80.18%、77.31%。结论临床在对不同级别前列腺癌鉴别诊断中,采用磁共振DWI纹理特征具有较高的价值,可以有效准确鉴别出低危和高危前列腺癌。展开更多
基金financially supported by the National Natural Science Foundation of China(NNSF,Grant No.51534007)。
文摘In crude oil transportation, adhesion of oil on pipe wall can cause partial or total blockage of the pipe. This process is significantly affected by wall sticking occurrence temperature(WSOT). In this work, an efficient approach for estimating WSOT of high water-cut oil, which can agree well with the actual environment of multiphase transportation pipeline, is proposed. Based on the energy dissipation theory, it is possible to make comparison of average shear rates between the stirred vessel and the flow loop. The impacts of water content and shear rate on WSOT are investigated using the stirred vessel and the flow loop. Good agreement has been observed between the stirred vessel and the flow loop results with the maximum and the average absolute deviations equating to 3.30 °C and 2.18 °C, respectively. The development of gathering scheme can enjoy some benefits from this method.
基金supported by the National Natural Science Foundation of China(NNFC,Grant No.51534007).
文摘To study the wall-sticking phenomenon and prevent pipeline blockage accidents,two analytical methods are used to evaluate the influence of different crude oil components on the wall-sticking occurrence temperature(WSOT).The WSOT and the interactions among oil,water,and surface solids are measured and calculated by various devices under different values of the wax content,water pH,and salinity.The results show that there is greater correlation between the wax content and WSOT than between resins/asphaltenes and WSOT.Furthermore,the wax content,water pH,and salinity have different effects on WSOT.There is generally a positive correlation between wax content and WSOT,whereas the maximum WSOT occurs when the water pH is in the range 5.7–6.5,and decreases under more acidic or alkaline conditions.As the salinity increases,WSOT decreases slightly,but quickly becomes saturated.In terms of interactions,variations in the interfacial tension and adhesion work with pH and salinity are consistent with that of WSOT,while the contact angle exhibits the opposite relation.
文摘目的探讨临床对不同级别前列腺癌鉴别诊断中行磁共振弥散加权成像(diffusion-weighted imaging,DWI)纹理特征分析的价值。方法选取2018年9月至2023年3月中山大学附属第七医院就诊的前列腺癌患者作为调查对象,病例数量共60例。全体患者均通过手术或穿刺活检病理检查得到证实,术前接受磁共振扫查,由医师借助ITK-SNAP软件手动在DWI上描画出感兴趣区(region of interest,ROI),并使用AK软件获得412个纹理特征,观察筛选在低危(n=15)和高危(n=45)前列腺癌患者中具有明显差异的纹理特征。采用受试者工作特征(receiver operating characteristics,ROC)曲线对各项参数诊断效能作出评估,并建立随机森林(random forest,RF)分类器,通过ROC曲线对模型诊断效能作出评价,最后通过交叉验证方法对模型鲁棒性进行验证。结果通过筛选后共获得了12个纹理特征,在建立的模型中,对低危和高危前列腺癌进行鉴别的ROC的曲线下面积(the area under the ROC curve,AUC)为0.96,准确性、灵敏度、特异度分别为99.07%、100%、98.12%,其中GLCMEnergyangle45offset1是该模型中最为重要的纹理特征参数。从交叉验证结果可知,本研究所建立模型的精确度、灵敏度、特异度分别为78.09%、80.18%、77.31%。结论临床在对不同级别前列腺癌鉴别诊断中,采用磁共振DWI纹理特征具有较高的价值,可以有效准确鉴别出低危和高危前列腺癌。
