The sealing integrity of cement sheath in offshore wells is seriously threatened under high-temperature conditions,resulting in gas channeling and other problems.Given the lack of experimental results,in this study re...The sealing integrity of cement sheath in offshore wells is seriously threatened under high-temperature conditions,resulting in gas channeling and other problems.Given the lack of experimental results,in this study relevant samples of a cement slurry sealing section of a typical offshore high-temperature well have been prepared and analyzed.In particular,the mechanical properties have been assessed with a triaxial pressure servo instrument and a high-temperature curing kettle.The density and the Poisson’s ratio of the samples have also been tested.The stress-strain curve has been drawn to obtain the elastic modulus and the compressive strength.The rock brittleness index has been calculated according to the measured elastic modulus and the Poisson’s ratio,together with the brittleness and the compressibility of the cement samples.The test results show that the mechanical properties and bonding strength of the cement samples are optimal at 130°C,medium at 150°C,and poor at 180°C.展开更多
Background:Upper blepharoplasty is one of the most commonly performed esthetic surgeries,but injection pain during local anesthesia often disturbs patients.The objective of this study was to identify the pain levels a...Background:Upper blepharoplasty is one of the most commonly performed esthetic surgeries,but injection pain during local anesthesia often disturbs patients.The objective of this study was to identify the pain levels associated with anesthetizing the upper eyelids in blepharoplasty and determine whether injection with thin needles is associated with less pain and bleeding than injection with thick needles.Methods:The study included 50 patients who underwent bilateral upper blepharoplasty.The eyelids were anesthetized using 2%lidocaine with 1:100000 epinephrine.One upper eyelid was randomly injected with a thin needle(26G)and the other with a thick needle(22G).The pain level was scored by patients immediately after the injection of each eyelid using a visual analog scale(VAS)ranging from 0 to 10.The incidence of eyelid hematomas caused by the anesthetic injection was also recorded.Results:The VAS scores in eyelids injected with thin needles were not significantly lower than those in eyelids injected with thick needles(4.0 vs.4.0,P=0.393).The formation of eyelid bruises caused by thin-needle injection was less frequent than that caused by thick-needle injection(16%vs.26%),but there was no significant difference between the two groups(P=0.326).Conclusion:Using thin needles for local anesthesia during upper blepharoplasty could not significantly decrease injection pain or hematoma occurrence compared with that associated with using thick needles.展开更多
基金The authors gratefully acknowledge the research project from Engineering Research Center of Rock-Soil Drilling&Excavation and Protection,Ministry of EducationChina University of Geosciences,Wuhan(Grant No.202106).
文摘The sealing integrity of cement sheath in offshore wells is seriously threatened under high-temperature conditions,resulting in gas channeling and other problems.Given the lack of experimental results,in this study relevant samples of a cement slurry sealing section of a typical offshore high-temperature well have been prepared and analyzed.In particular,the mechanical properties have been assessed with a triaxial pressure servo instrument and a high-temperature curing kettle.The density and the Poisson’s ratio of the samples have also been tested.The stress-strain curve has been drawn to obtain the elastic modulus and the compressive strength.The rock brittleness index has been calculated according to the measured elastic modulus and the Poisson’s ratio,together with the brittleness and the compressibility of the cement samples.The test results show that the mechanical properties and bonding strength of the cement samples are optimal at 130°C,medium at 150°C,and poor at 180°C.
基金the National Natural Science Foundation of China(grant no.31870974).
文摘Background:Upper blepharoplasty is one of the most commonly performed esthetic surgeries,but injection pain during local anesthesia often disturbs patients.The objective of this study was to identify the pain levels associated with anesthetizing the upper eyelids in blepharoplasty and determine whether injection with thin needles is associated with less pain and bleeding than injection with thick needles.Methods:The study included 50 patients who underwent bilateral upper blepharoplasty.The eyelids were anesthetized using 2%lidocaine with 1:100000 epinephrine.One upper eyelid was randomly injected with a thin needle(26G)and the other with a thick needle(22G).The pain level was scored by patients immediately after the injection of each eyelid using a visual analog scale(VAS)ranging from 0 to 10.The incidence of eyelid hematomas caused by the anesthetic injection was also recorded.Results:The VAS scores in eyelids injected with thin needles were not significantly lower than those in eyelids injected with thick needles(4.0 vs.4.0,P=0.393).The formation of eyelid bruises caused by thin-needle injection was less frequent than that caused by thick-needle injection(16%vs.26%),but there was no significant difference between the two groups(P=0.326).Conclusion:Using thin needles for local anesthesia during upper blepharoplasty could not significantly decrease injection pain or hematoma occurrence compared with that associated with using thick needles.
