The paper provides an insight into key engineering aspects of Kuwait Oil Company＇s existing projects, facilities and equipment both current and from nearly 30 years of projects development. It deals with engineering ...The paper provides an insight into key engineering aspects of Kuwait Oil Company＇s existing projects, facilities and equipment both current and from nearly 30 years of projects development. It deals with engineering features of mainly process and mechanical equipment, both static and rotating besides others, used for collection, separation, desalting, heat transfer, chemical treatment, storage, transmission, pipelines and similar facilities utilized for upstream oil and gas production, both sweet and sour. Engineering highlights include certain technological developments, metallurgical aspects, few best practices and lessons learnt as well. Seven （7） case studies are included towards the end that show case some of the engineering aspects of facility equipment, lessons learned from their engineering and conclusions drawn that, emphasize the need to focus on initial, preliminary engineering aspects of projects and could provide useful tips for oil and gas engineers and designers.展开更多
In this paper,the dynamic stress concentration and scattering of SH-waves by bi-material structures that possess an interface elliptic cavity are investigated.First,by using the complex function method,the Green's...In this paper,the dynamic stress concentration and scattering of SH-waves by bi-material structures that possess an interface elliptic cavity are investigated.First,by using the complex function method,the Green's function is constructed.This yields the solution of the displacement field for an elastic half space with a semi-elliptic canyon impacted by an anti-plane harmonic line source loading on the horizontal surface.Then,the problem is divided into an upper and lower half space along the horizontal interface,regarded as a harmony model.In order to satisfy the integral continuity condition, the unknown anti-plane forces are applied to the interface.The integral equations with unknown forces can be established through the continuity condition,and after transformation,the algebraic equations are solved numerically.Finally,the distribution of the dynamic stress concentration factor(DSCF)around the elliptic cavity is given and the effect of different parameters on DSCF is discussed.展开更多
The mineral assemblage and content and surface microtextures of slipping zone soil of several landslides in the Three Gorges Reservoir District have been analyzed using the scanning electron microscope (SEM) and X-ray...The mineral assemblage and content and surface microtextures of slipping zone soil of several landslides in the Three Gorges Reservoir District have been analyzed using the scanning electron microscope (SEM) and X-ray diffractometer (XRD). All the mineral assemblages are similar in these landslides. The main minerals are montmorillonite, illite, kaolinite, chlorite, quartz and feldspar. There are two kinds of surface microtexture in the slipping zone soil, i.e., linear scratches and arcuate scratches. Based on analyses of the changes of the microtextures, one can obtain information about the number, directions and stages of landslide movements. The authors have also studied the mechanism of landslide formation, evaluated the stability of landslides and revival possibility of ancient landslides and forecasted the activity of similar landslides in different districts. The surface microtexture features of stable landslides and mobile landslides are summarized and it is concluded that the existence of filamentous bacteria may result in or increase movements of landslides.展开更多
The influence of a key process variable on the mold filling characteristics of AZ91 Mg-alloy was studied in the low pressure EPC process.The applied flow quantity of insert gas from 1 to 5 m~3/h associated with the pr...The influence of a key process variable on the mold filling characteristics of AZ91 Mg-alloy was studied in the low pressure EPC process.The applied flow quantity of insert gas from 1 to 5 m~3/h associated with the pressurizing rate in the low pressure EPC casting process was considered for rectangle and L-shape plate casting. The experimental results show that there is an optimal flow quantity of insert gas for good mold filling characteristics in AZ91 Mg-alloy low-pressure EPC process. The optimal flow quantity of insert gas for the specimens is 3 to 4 m~3/h. Either less or higher than the optimal flow quantity of insert gas would lead to misrun defects or folds, blisters and porosity defects. The practice of hub casting confirmed that the low-pressure EPC process with an optimal processing variable exemplified as 4 m~3/h gas flow quantity was capable of producing complicated magnesium castings without misrun defects.展开更多
Dadu River is an important tributary of the Yangtze River in China. The Shuangjiangkou Hydropower Station is the control reservoir upstream of the main trunk of Dadu River. Located in the Aba Tibetan and Qiang Autonom...Dadu River is an important tributary of the Yangtze River in China. The Shuangjiangkou Hydropower Station is the control reservoir upstream of the main trunk of Dadu River. Located in the Aba Tibetan and Qiang Autonomous Prefecture of Sichuan Province, the project is mainly aimed at power generation and flood control.展开更多
A series of transparent casting polyurethane resins (TCPU) were synthesized from cycloaliphatic diisocyanate (IPDI or H_(12)MDI), polyol, chain extender, crosslinking agents, catalyst and special aids (T),which were c...A series of transparent casting polyurethane resins (TCPU) were synthesized from cycloaliphatic diisocyanate (IPDI or H_(12)MDI), polyol, chain extender, crosslinking agents, catalyst and special aids (T),which were characterized by FTIR. The thermal stabilities of the obtained TCPU were examined by DSC and TGA, the glass transition temperature (T_g) was in the range of 95-110 ℃, the initial decomposition temperature (5% weight loss) was 250-265 ℃, and 10% weight loss at the temperature was in the range of 260-286℃ in nitrogen atmosphere. The morphologies of the fractured surfaces of TCPU were revealed by a scanning electron microscope (SEM). The crystalline-amorphous characters of TCPU were studied by WAXD, the result shows that TCPU possesses amorphous glassy characters. The optical properties of TCPU were studied by a UV-7500 visible light absorbance measurement. All the samples exhibited excellent optical properties and possessed light transmittance in the range of 91%-93%.展开更多
A new collapse model of the trapdoors,three-dimensional rectangular trapdoor(3DRT),is presented for ground surface collapse.Undrained stability of 3DRT is examined with the upper bound method of plasticity limit analy...A new collapse model of the trapdoors,three-dimensional rectangular trapdoor(3DRT),is presented for ground surface collapse.Undrained stability of 3DRT is examined with the upper bound method of plasticity limit analysis theory.The soil where the trapdoors are located is assumed to be a perfectly plastic model with a Tresca yield criterion.Block analysis technique is employed to investigate the collapse of 3DRT.The model is divided into five different block types and added up to ten rigid blocks.According to the law of conservation of energy,the critical stability ratios of 3DRT are obtained through a search proceeding.The results of upper bound solution for 3DRT are given,and three trapdoor models with depth various are discussed during the application in the stability analysis of square trapdoors.The critical stability ratios can be used in the design of underground excavation and support force.展开更多
This paper describes a versatile and computationally efficient method for coupling several finite element analysis(FEA)programs together so that the unique modeling and analysis capabilities of each code can be utiliz...This paper describes a versatile and computationally efficient method for coupling several finite element analysis(FEA)programs together so that the unique modeling and analysis capabilities of each code can be utilized simultaneously to simulate the static or dynamic response of a complete numerical system.An arbitrary number of finite element analysis software packages can be coupled by adding two special types of elements,namely generic and adapter elements,to each of the finite element applications using their programming interface.These elements are inserted at the interfaces between the different sub-domains of the complete system modeled by each finite element analysis software package.Exchange of data between the coupled FEA codes is accomplished in a modular and synchronized manner using OpenFresco(Opensource Framework for Experimental Setup and Control).OpenFresco is an objectoriented,environment independent software framework initially developed for hybrid simulation in which certain aspects of a complete structure are simulated numerically and other aspects are simultaneously tested physically.An important practical advantage of this coupled analysis approach is that all of the connected FEA codes run concurrently and continuously,decreasing analysis time consumption by an order of magnitude or more compared to more traditional approaches that shut down and restart the coupled analysis codes at each integration time step.The implementation and accuracy of this approach to FE software coupling are demonstrated using dynamic analyses of three simple structural models from the field of earthquake engineering.展开更多
A novel photosensitive prepolymer of trimethylolpropane triglycidylether triacrylate was synthesized by utilizing trimethylolpropane triglycidylether and acrylic acid as two starting materials, triphenyl phosphine as ...A novel photosensitive prepolymer of trimethylolpropane triglycidylether triacrylate was synthesized by utilizing trimethylolpropane triglycidylether and acrylic acid as two starting materials, triphenyl phosphine as catalyst and p-hydroxyanisole as inhibitor. The optimum synthesis conditions were that the concentration of triphenyl phosphine was 0.85wt% of reactants, the concentration of p-hydroxyanisole was 0.3wt% of reactants, and the reaction temperature was at 90-110 ℃. Benzil dimethyl ketal of a UV-cured initiator was added to the synthesized trimethylolpropane triglycidylether triacrylate to prepare a kind of UV-cured coating. The mechanical properties of the UV-cured films were determined, giving 28.43 MPa of tensile strength, 965.59MPa of (Young's) modulus and 4.10% of elongation at tear.展开更多
A systematic research on the pyrolysis process of polymethysilicone (SAR-2) and the thermostability of the pyrolysis residue was made by the thermogravimetric analysis, DTA and infrared spectroscopy.The experimental r...A systematic research on the pyrolysis process of polymethysilicone (SAR-2) and the thermostability of the pyrolysis residue was made by the thermogravimetric analysis, DTA and infrared spectroscopy.The experimental results indicate that the pyrolysis residue of SAR-2 converted into the amorphous SiC_xO_(4-x) phase above 900 ℃,the residue at 1200 ℃ is the most thermostable and antioxidant.It is suitable to be used as polysilicone preceramic.展开更多
Based on the refraction-diffraction theory of irregular waves in the waters of slowly-varying currents and depths, and the generation dissipation theory of wind wave, a model for nonlinear irregular waves in coastal a...Based on the refraction-diffraction theory of irregular waves in the waters of slowly-varying currents and depths, and the generation dissipation theory of wind wave, a model for nonlinear irregular waves in coastal area is developed. In light of the specific conditions of coastal wave character and engineering application, a practical mathematical model for the nonlinear irregular waves is presented, with directional spectrum in coastal area. Coast effect, refraction, whitecapping, bottom friction, current, wind and nonlinear action are considered in this model. The numerical methods and schemes for wave refraction ray, energy conservation of propagation, energy balance of the generation and dissipation of wind waves have been studied. Finally, the model is used for the directional wave spectrum computation in the Daya Bay. Compared with the measured data with 956 wave bouys in the Daya Bay, the model results are in good agreement with the measured results.展开更多
X-ray Computed Tomography(XCT)enables non-destructive acquisition of the internal structure of materials,and image segmentation plays a crucial role in analyzing material XCT images.This paper proposes an image segmen...X-ray Computed Tomography(XCT)enables non-destructive acquisition of the internal structure of materials,and image segmentation plays a crucial role in analyzing material XCT images.This paper proposes an image segmentation method based on the Segment Anything model(SAM).We constructed a dataset of carbide in nickel-based single crystal superalloys XCT images and preprocessed the images using median filtering,histogram equalization,and gamma correction.Subsequently,SAM was fine-tuned to adapt to the task of material XCT image segmentation,resulting in Material-SAM.We compared the performance of threshold segmentation,SAM,U-Net model,and Material-SAM.Our method achieved 88.45%Class Pixel Accuracy(CPA)and 88.77%Dice Similarity Coefficient(DSC)on the test set,outperforming SAM by 5.25%and 8.81%,respectively,and achieving the highest evaluation.Material-SAM demonstrated lower input requirements compared to SAM,as it only required three reference points for completing the segmentation task,which is one-fifth of the requirement of SAM.Material-SAM exhibited promising results,highlighting its potential as a novel method for material XCT image segmentation.展开更多
Beijing Tongrentang(TRT) is a famous time-honored brand in traditional Chinese medicine (TCM) industry.In 1669,the 8th year of Emperor Kangxi's reign of the Qing Dynasty(1644-1911),TRT was found by Yue Xianyang,an...Beijing Tongrentang(TRT) is a famous time-honored brand in traditional Chinese medicine (TCM) industry.In 1669,the 8th year of Emperor Kangxi's reign of the Qing Dynasty(1644-1911),TRT was found by Yue Xianyang,an imperial physician in Beijing.It was 188 years when TRT served the royal courts from 1723 to 1911.TRT earned customers' trust with its persistent philosophy of quality。展开更多
Ten full-scale steel beam-to-column moment connections used in moment-resisting frames （MRFs） were tested to study the failure process, failure mode, strength and plastic rotation capacity. The specimens include one...Ten full-scale steel beam-to-column moment connections used in moment-resisting frames （MRFs） were tested to study the failure process, failure mode, strength and plastic rotation capacity. The specimens include one traditional welded flange-bolted web connection, one traditional fully welded connection, four beam flange strengthened connections, three beam flange weakened connections, and one through-diaphragm connection. The test results show that the connections with flange cover plates or with partly cut beam flanges satisfy the beam plastic rotation demand for ductile MRFs. From the measured stress profiles along the beam flange and beam web depth, the mechanics of brittle fracture at the end of the beam is discussed. Design recommendations for steel beam-to-column moment connections are proposed.展开更多
文摘The paper provides an insight into key engineering aspects of Kuwait Oil Company＇s existing projects, facilities and equipment both current and from nearly 30 years of projects development. It deals with engineering features of mainly process and mechanical equipment, both static and rotating besides others, used for collection, separation, desalting, heat transfer, chemical treatment, storage, transmission, pipelines and similar facilities utilized for upstream oil and gas production, both sweet and sour. Engineering highlights include certain technological developments, metallurgical aspects, few best practices and lessons learnt as well. Seven （7） case studies are included towards the end that show case some of the engineering aspects of facility equipment, lessons learned from their engineering and conclusions drawn that, emphasize the need to focus on initial, preliminary engineering aspects of projects and could provide useful tips for oil and gas engineers and designers.
文摘In this paper,the dynamic stress concentration and scattering of SH-waves by bi-material structures that possess an interface elliptic cavity are investigated.First,by using the complex function method,the Green's function is constructed.This yields the solution of the displacement field for an elastic half space with a semi-elliptic canyon impacted by an anti-plane harmonic line source loading on the horizontal surface.Then,the problem is divided into an upper and lower half space along the horizontal interface,regarded as a harmony model.In order to satisfy the integral continuity condition, the unknown anti-plane forces are applied to the interface.The integral equations with unknown forces can be established through the continuity condition,and after transformation,the algebraic equations are solved numerically.Finally,the distribution of the dynamic stress concentration factor(DSCF)around the elliptic cavity is given and the effect of different parameters on DSCF is discussed.
文摘The mineral assemblage and content and surface microtextures of slipping zone soil of several landslides in the Three Gorges Reservoir District have been analyzed using the scanning electron microscope (SEM) and X-ray diffractometer (XRD). All the mineral assemblages are similar in these landslides. The main minerals are montmorillonite, illite, kaolinite, chlorite, quartz and feldspar. There are two kinds of surface microtexture in the slipping zone soil, i.e., linear scratches and arcuate scratches. Based on analyses of the changes of the microtextures, one can obtain information about the number, directions and stages of landslide movements. The authors have also studied the mechanism of landslide formation, evaluated the stability of landslides and revival possibility of ancient landslides and forecasted the activity of similar landslides in different districts. The surface microtexture features of stable landslides and mobile landslides are summarized and it is concluded that the existence of filamentous bacteria may result in or increase movements of landslides.
文摘The influence of a key process variable on the mold filling characteristics of AZ91 Mg-alloy was studied in the low pressure EPC process.The applied flow quantity of insert gas from 1 to 5 m~3/h associated with the pressurizing rate in the low pressure EPC casting process was considered for rectangle and L-shape plate casting. The experimental results show that there is an optimal flow quantity of insert gas for good mold filling characteristics in AZ91 Mg-alloy low-pressure EPC process. The optimal flow quantity of insert gas for the specimens is 3 to 4 m~3/h. Either less or higher than the optimal flow quantity of insert gas would lead to misrun defects or folds, blisters and porosity defects. The practice of hub casting confirmed that the low-pressure EPC process with an optimal processing variable exemplified as 4 m~3/h gas flow quantity was capable of producing complicated magnesium castings without misrun defects.
文摘Dadu River is an important tributary of the Yangtze River in China. The Shuangjiangkou Hydropower Station is the control reservoir upstream of the main trunk of Dadu River. Located in the Aba Tibetan and Qiang Autonomous Prefecture of Sichuan Province, the project is mainly aimed at power generation and flood control.
文摘A series of transparent casting polyurethane resins (TCPU) were synthesized from cycloaliphatic diisocyanate (IPDI or H_(12)MDI), polyol, chain extender, crosslinking agents, catalyst and special aids (T),which were characterized by FTIR. The thermal stabilities of the obtained TCPU were examined by DSC and TGA, the glass transition temperature (T_g) was in the range of 95-110 ℃, the initial decomposition temperature (5% weight loss) was 250-265 ℃, and 10% weight loss at the temperature was in the range of 260-286℃ in nitrogen atmosphere. The morphologies of the fractured surfaces of TCPU were revealed by a scanning electron microscope (SEM). The crystalline-amorphous characters of TCPU were studied by WAXD, the result shows that TCPU possesses amorphous glassy characters. The optical properties of TCPU were studied by a UV-7500 visible light absorbance measurement. All the samples exhibited excellent optical properties and possessed light transmittance in the range of 91%-93%.
基金the Fundamental Research Funds for the Provincial Universities,China(No.702/000007020303)。
文摘A new collapse model of the trapdoors,three-dimensional rectangular trapdoor(3DRT),is presented for ground surface collapse.Undrained stability of 3DRT is examined with the upper bound method of plasticity limit analysis theory.The soil where the trapdoors are located is assumed to be a perfectly plastic model with a Tresca yield criterion.Block analysis technique is employed to investigate the collapse of 3DRT.The model is divided into five different block types and added up to ten rigid blocks.According to the law of conservation of energy,the critical stability ratios of 3DRT are obtained through a search proceeding.The results of upper bound solution for 3DRT are given,and three trapdoor models with depth various are discussed during the application in the stability analysis of square trapdoors.The critical stability ratios can be used in the design of underground excavation and support force.
基金Funding for this work was provided in part by the National Science Foundation through a subaward from the NEES Consortium,Inc.under Cooperative Agreement CMS0402490.The authors appreciate the assistance of Dr.Frank McKenna of the University of California,Berkeley,Dr.John Hallquist of Livermore Software Technology Corporation,and Prof.Yoshikazu Takahashi of Kyoto University.The findings and conclusions are those of the authors alone,and may not reflect those of the sponsors.
文摘This paper describes a versatile and computationally efficient method for coupling several finite element analysis(FEA)programs together so that the unique modeling and analysis capabilities of each code can be utilized simultaneously to simulate the static or dynamic response of a complete numerical system.An arbitrary number of finite element analysis software packages can be coupled by adding two special types of elements,namely generic and adapter elements,to each of the finite element applications using their programming interface.These elements are inserted at the interfaces between the different sub-domains of the complete system modeled by each finite element analysis software package.Exchange of data between the coupled FEA codes is accomplished in a modular and synchronized manner using OpenFresco(Opensource Framework for Experimental Setup and Control).OpenFresco is an objectoriented,environment independent software framework initially developed for hybrid simulation in which certain aspects of a complete structure are simulated numerically and other aspects are simultaneously tested physically.An important practical advantage of this coupled analysis approach is that all of the connected FEA codes run concurrently and continuously,decreasing analysis time consumption by an order of magnitude or more compared to more traditional approaches that shut down and restart the coupled analysis codes at each integration time step.The implementation and accuracy of this approach to FE software coupling are demonstrated using dynamic analyses of three simple structural models from the field of earthquake engineering.
文摘A novel photosensitive prepolymer of trimethylolpropane triglycidylether triacrylate was synthesized by utilizing trimethylolpropane triglycidylether and acrylic acid as two starting materials, triphenyl phosphine as catalyst and p-hydroxyanisole as inhibitor. The optimum synthesis conditions were that the concentration of triphenyl phosphine was 0.85wt% of reactants, the concentration of p-hydroxyanisole was 0.3wt% of reactants, and the reaction temperature was at 90-110 ℃. Benzil dimethyl ketal of a UV-cured initiator was added to the synthesized trimethylolpropane triglycidylether triacrylate to prepare a kind of UV-cured coating. The mechanical properties of the UV-cured films were determined, giving 28.43 MPa of tensile strength, 965.59MPa of (Young's) modulus and 4.10% of elongation at tear.
文摘A systematic research on the pyrolysis process of polymethysilicone (SAR-2) and the thermostability of the pyrolysis residue was made by the thermogravimetric analysis, DTA and infrared spectroscopy.The experimental results indicate that the pyrolysis residue of SAR-2 converted into the amorphous SiC_xO_(4-x) phase above 900 ℃,the residue at 1200 ℃ is the most thermostable and antioxidant.It is suitable to be used as polysilicone preceramic.
基金Chinese Academy of Sciences:the"Ninth Five-Year Plan"important resourcesenvironment research project"pipeline in seabed"(No.KZ951-A1-405)alse by the Chinese"Ninth Five-Year Plan"strategic research project"examinacion in Nansha Islands"(N
文摘Based on the refraction-diffraction theory of irregular waves in the waters of slowly-varying currents and depths, and the generation dissipation theory of wind wave, a model for nonlinear irregular waves in coastal area is developed. In light of the specific conditions of coastal wave character and engineering application, a practical mathematical model for the nonlinear irregular waves is presented, with directional spectrum in coastal area. Coast effect, refraction, whitecapping, bottom friction, current, wind and nonlinear action are considered in this model. The numerical methods and schemes for wave refraction ray, energy conservation of propagation, energy balance of the generation and dissipation of wind waves have been studied. Finally, the model is used for the directional wave spectrum computation in the Daya Bay. Compared with the measured data with 956 wave bouys in the Daya Bay, the model results are in good agreement with the measured results.
基金This work was supported by the National Natural Science Foundation of China(Grant Number 52073030)National Natural Science Foundation of China-Guangxi Joint Fund(U20A20276).
文摘X-ray Computed Tomography(XCT)enables non-destructive acquisition of the internal structure of materials,and image segmentation plays a crucial role in analyzing material XCT images.This paper proposes an image segmentation method based on the Segment Anything model(SAM).We constructed a dataset of carbide in nickel-based single crystal superalloys XCT images and preprocessed the images using median filtering,histogram equalization,and gamma correction.Subsequently,SAM was fine-tuned to adapt to the task of material XCT image segmentation,resulting in Material-SAM.We compared the performance of threshold segmentation,SAM,U-Net model,and Material-SAM.Our method achieved 88.45%Class Pixel Accuracy(CPA)and 88.77%Dice Similarity Coefficient(DSC)on the test set,outperforming SAM by 5.25%and 8.81%,respectively,and achieving the highest evaluation.Material-SAM demonstrated lower input requirements compared to SAM,as it only required three reference points for completing the segmentation task,which is one-fifth of the requirement of SAM.Material-SAM exhibited promising results,highlighting its potential as a novel method for material XCT image segmentation.
文摘Beijing Tongrentang(TRT) is a famous time-honored brand in traditional Chinese medicine (TCM) industry.In 1669,the 8th year of Emperor Kangxi's reign of the Qing Dynasty(1644-1911),TRT was found by Yue Xianyang,an imperial physician in Beijing.It was 188 years when TRT served the royal courts from 1723 to 1911.TRT earned customers' trust with its persistent philosophy of quality。
文摘Ten full-scale steel beam-to-column moment connections used in moment-resisting frames （MRFs） were tested to study the failure process, failure mode, strength and plastic rotation capacity. The specimens include one traditional welded flange-bolted web connection, one traditional fully welded connection, four beam flange strengthened connections, three beam flange weakened connections, and one through-diaphragm connection. The test results show that the connections with flange cover plates or with partly cut beam flanges satisfy the beam plastic rotation demand for ductile MRFs. From the measured stress profiles along the beam flange and beam web depth, the mechanics of brittle fracture at the end of the beam is discussed. Design recommendations for steel beam-to-column moment connections are proposed.
