We derived an equation for saturation in carbonate reservoirs based on the electrical efficiency model in the case of lacking core data. Owing to the complex pore structure and strong heterogeneity in carbonate reserv...We derived an equation for saturation in carbonate reservoirs based on the electrical efficiency model in the case of lacking core data. Owing to the complex pore structure and strong heterogeneity in carbonate reservoirs, the relation between electrical efficiency and water porosity is either complex or linear. We proposed an electrical efficiency equation that accounts for the relation between electrical efficiency and water porosity. We also proposed a power-law relation between electrical efficiency and deep-formation resistivity and analyzed the factors controlling the error in the water saturation computations. We concluded that the calculation accuracy of the electrical efficiency is critical to the application of the saturation equation. The saturation equation was applied to the carbonate reservoirs of three wells in Iraq and Indonesia. For relative rock electrical efficiency error below 0.1, the water saturation absolute error is also below 0.1. Therefore, we infer that the proposed saturation equation generally satisfies the evaluation criteria for carbonate reservoirs.展开更多
Objective:The aim of this study was to observe the effect of endobronchial blocker tube in the pulmonary carcinoma with video-assisted thoracic surgery.Methods:Forty patients of pulmonary carcinoma with video-assisted...Objective:The aim of this study was to observe the effect of endobronchial blocker tube in the pulmonary carcinoma with video-assisted thoracic surgery.Methods:Forty patients of pulmonary carcinoma with video-assisted thoracic surgery were randomly assigned into two groups with twenty cases each:endobronchial blocker tube group(group 1) and double-lumen endobronchial tube group(group 2).After anesthesia was induced,in group 1,single lumen tube was intubated at first,and then endobronchial blocker tube intubated to left or right primary bronchus under the guidance of fiber-optic bronchoscope according to operational necessary,injected 2-4 mL air to blocker balloon and blocker one lateral primary bronchus for one-lung ventilation necessarily;while in group 2,the position of double-lumen endobronchial tube was confirmed with fiber-optic bronchoscope after intubation.Blood samples were collected before anesthesia induction,double lumen ventilation,at the one-lung ventilation of 5 min,30 min,60 min,120 min and 180 min,SBP,DBP,HR,SpO2,partial pressure of end tidal carbon dioxide(PetCO2),pH,PaO2,PaCO2,PaO2/FiO2 were recorded.Results:Forty cases' intubations were all successful.There were no differences in SBP,DBP,HR,SpO2,PetCO2,pH,PaCO2 between two groups in different points(P > 0.05).Paw in group 1 was lower than group 2,PaO2 and PaO2/FiO2 in group 1 was higher than group 2 in the one lung ventilation of 5 min,30 min,60 min,120 min and 180 min.Conclusion:The endobronchial blocker tube can meet the request of video-assisted thoracic surgery,with the special advantages of simple insertion,lower airway and better oxygenation.Endobronchial blocker tube offer a new way for one-lung ventilation in the pulmonary carcinoma with video-assisted thoracic surgery.展开更多
It is fundamental that changes in coal reservoir permeability are researched, in particular, the accurate determination of variations in the coal matrix caused by CO2 replacing CH4 at different gas saturation conditio...It is fundamental that changes in coal reservoir permeability are researched, in particular, the accurate determination of variations in the coal matrix caused by CO2 replacing CH4 at different gas saturation conditions. Based on the surface free energy, the extended Langmuir isothermal adsorption model, combined with CO2 replacing CH4 in experimental trials, and calling on the more general principles and characteristics of the field, mathematical models describing the coal matrix as it undergoes different processes such as CO2 injection and desorption were established. Combined with laboratory data about CO2 replacement under different methane saturation conditions, a law governing the variations in coal matrix CO2 replacement under different methane gas saturation conditions was obtained. The results showed that： in the injection process, the coal matrix expansion rate caused by CO2 or CH4 was exponentially increased with the CO2 pressure increase, the expansion caused by CO2 was far greater than the expansion caused by CH4 in the desorption process, the coal matrix shrinkage caused by CO2 or CH4 was exponentially increased with the pressure decrease, the shrinkage caused by CO2 was larger than the shrinkage caused by CH4 under the same pressure and different gas saturation, the total shrinkage in the desorption process in the coal matrix was greater than the total expansion in the injection process. At higher gas saturations, the total coal matrix shrinkage volume exceeded the total expansion corresponding to pressure points higher in the desorption process.展开更多
The world is currently facing the challenges of global warming and climate change. Numerous efforts have been taken to mitigate CO2 emission, among which is the use of solid sorbents for CO2 capture. In this work, Li4...The world is currently facing the challenges of global warming and climate change. Numerous efforts have been taken to mitigate CO2 emission, among which is the use of solid sorbents for CO2 capture. In this work, Li4SiO4 was synthesised via a sol-gel method using lithium nitrate （LiNO3） and tetraethylorthosilicate （SiC8H20O4） as precursors. A parametric study of Li：Si molar ratio （1-5）, calcination temperature （600-800℃） and calcination time （1-8 h） were conducted during sorbent synthesis. Calcination temperature （700-800℃） and carbonation temperature （500-700℃） during CO2 sorption activity were also varied to confirm the optimum operating temperature. Sorbent with the highest CO2 sorption capacity was finally introduced to several cyclic tests to study the durability of the sorbent through 10 cycles of CO2 sorption-desorption test. The results showed that the calcination temperature of 800℃ and carbonation temperature of 700℃ were the best operating temperatures, with CO2 sorption capacity of 7.95 mmol CO2·（g sorbent）^-1 （93% of the theoretical yield）. Throughout the ten cyclic processes, CO2 sorption capacity of the sorbent had dropped approximately 16.2% from the first to the tenth cycle, which was a reasonable decline. Thus, it was concluded that Li4SiO4 is a potential CO2 solid sorbent for high temperature CO2 capture activity.展开更多
The photochemical mineralization of dissolved organic carbon(DOC) to dissolved inorganic carbon(DIC) is a key process in carbon cycling.Using a Suntest CPS solar simulator,Suwannee River humic acid(SRHA) was photooxid...The photochemical mineralization of dissolved organic carbon(DOC) to dissolved inorganic carbon(DIC) is a key process in carbon cycling.Using a Suntest CPS solar simulator,Suwannee River humic acid(SRHA) was photooxidated to examine the effects of O2 levels,the wavelength of incident light,and the concentration of Fe on the photoproduction of DIC.Increasing the O2 abundance enhanced photodegradation of SRHA.The rate of DIC photoproduction under air saturation in the first 24 h(4.40 μmol/(L h)) was increased by a factor of 1.56 under O2 saturation,but fell by only 36% under N2 saturation.To evaluate the relative importance of UV-B,UV-A,and visible radiation in the photodegradation,we examined the above process using Mylar-d films and UF-3 and UF-4 plexiglass filters.The results indicated that the UV-B,UV-A and visible wavelengths accounted for 31.8%,32.6% and 25.6%,respectively,of DIC production with simulated sunlight irradiation.The above results also indicated that photoproduction of DIC could take place in natural water at depths greater than those that UV light can reach.When 20 μmol/L desferrioxamine mesylate(DFOM,a strong Fe complexing ligand) was added,the rate of DIC photoproduction fell to 55.6% that of the original SRHA samples with 5.46 μmol/L Fe.展开更多
AIM: To characterize the profiles of alveolar hypoventilation during colonoscopies performed under sedoanalgesia with a combination of alfentanil and either midazolam or propofol. METHODS: Consecutive patients undergo...AIM: To characterize the profiles of alveolar hypoventilation during colonoscopies performed under sedoanalgesia with a combination of alfentanil and either midazolam or propofol. METHODS: Consecutive patients undergoing routine colonoscopy were randomly assigned to sedation with either propofol or midazolam in an open-labeled design using a titration scheme. All patients received 4 μg/kg per body weight alfentanil for analgesia and 3 L of supplemental oxygen. Oxygen saturation (SpO 2 ) was measured by pulse oximetry (POX), and capnography (PcCO 2 ) was continuously measured using a combined dedicated sensor at the ear lobe. Instances of apnea resulting in measures such as stimulation of the patient, a chin lift, a mask maneuver, or withholding of sedation were recorded. PcCO 2 values (as a parameter of sedation-induced hypoventilation) were compared between groups at the following distinct time points: baseline, maximal rise, termination of the procedure and 5 min after termination of the procedure. The number of patients in both study groups who regained baseline PcCO 2 values (± 1.5 mmHg) five minutes after the procedure was determined.RESULTS: A total of 97 patients entered this study. The data from 14 patients were subsequently excluded for clinical procedure-related reasons or for technical problems. Therefore, 83 patients (mean age 62 ± 13 years) were successfully randomized to receive propofol (n = 42) or midazolam (n = 41) for sedation. Most of the patients were classified as American Society of Anesthesiologists (ASA) Ⅱ [16 (38%) in the midazolam group and 15 (32%) in the propofol group] and ASA Ⅲ [14 (33%) and 13 (32%) in the midazolam and propofol groups, respectively]. A mean dose of 5 (4-7) mg of Ⅳ midazolam and 131 (70-260) mg of Ⅳ propofol was used during the procedure in the corresponding study arms. The mean SpO 2 at baseline (%) was 99 ± 1 for the midazolam group and 99 ± 1 for the propofol group. No cases of hypoxemia (SpO 2 < 85%) or apnea were recorded. However, an increase in PcCO 2 that indicated alveolar hypoventilation occurred in both groups after administration of the first drug and was not detected with pulse oximetry alone. The mean interval between the initiation of sedation and the time when the PcCO 2 value increased to more than 2 mmHg was 2.8 ± 1.3 min for midazolam and 2.8 ± 1.1 min for propofol. The mean maximal rise was similar for both drugs: 8.6 ± 3.7 mmHg for midazolam and 7.4 ± 3.2 mmHg for propofol. Five minutes after the end of the procedure, the mean difference from the baseline values was significantly lower for the propofol treatment compared with midazolam (0.9 ± 3.0 mmHg vs 4.3 ± 3.7 mmHg, P = 0.0000169), and significantly more patients in the propofol group had regained their baseline value ± 1.5 mmHg (32 of 41vs 12 of 42,P = 0.0004). CONCLUSION: A significantly higher number of patients sedated with propofol had normalized PcCO 2 values five minutes after sedation when compared with patients sedated with midazolam.展开更多
基金supported by the National Science and Technology Major Project(2011ZX05030)
文摘We derived an equation for saturation in carbonate reservoirs based on the electrical efficiency model in the case of lacking core data. Owing to the complex pore structure and strong heterogeneity in carbonate reservoirs, the relation between electrical efficiency and water porosity is either complex or linear. We proposed an electrical efficiency equation that accounts for the relation between electrical efficiency and water porosity. We also proposed a power-law relation between electrical efficiency and deep-formation resistivity and analyzed the factors controlling the error in the water saturation computations. We concluded that the calculation accuracy of the electrical efficiency is critical to the application of the saturation equation. The saturation equation was applied to the carbonate reservoirs of three wells in Iraq and Indonesia. For relative rock electrical efficiency error below 0.1, the water saturation absolute error is also below 0.1. Therefore, we infer that the proposed saturation equation generally satisfies the evaluation criteria for carbonate reservoirs.
文摘Objective:The aim of this study was to observe the effect of endobronchial blocker tube in the pulmonary carcinoma with video-assisted thoracic surgery.Methods:Forty patients of pulmonary carcinoma with video-assisted thoracic surgery were randomly assigned into two groups with twenty cases each:endobronchial blocker tube group(group 1) and double-lumen endobronchial tube group(group 2).After anesthesia was induced,in group 1,single lumen tube was intubated at first,and then endobronchial blocker tube intubated to left or right primary bronchus under the guidance of fiber-optic bronchoscope according to operational necessary,injected 2-4 mL air to blocker balloon and blocker one lateral primary bronchus for one-lung ventilation necessarily;while in group 2,the position of double-lumen endobronchial tube was confirmed with fiber-optic bronchoscope after intubation.Blood samples were collected before anesthesia induction,double lumen ventilation,at the one-lung ventilation of 5 min,30 min,60 min,120 min and 180 min,SBP,DBP,HR,SpO2,partial pressure of end tidal carbon dioxide(PetCO2),pH,PaO2,PaCO2,PaO2/FiO2 were recorded.Results:Forty cases' intubations were all successful.There were no differences in SBP,DBP,HR,SpO2,PetCO2,pH,PaCO2 between two groups in different points(P > 0.05).Paw in group 1 was lower than group 2,PaO2 and PaO2/FiO2 in group 1 was higher than group 2 in the one lung ventilation of 5 min,30 min,60 min,120 min and 180 min.Conclusion:The endobronchial blocker tube can meet the request of video-assisted thoracic surgery,with the special advantages of simple insertion,lower airway and better oxygenation.Endobronchial blocker tube offer a new way for one-lung ventilation in the pulmonary carcinoma with video-assisted thoracic surgery.
文摘It is fundamental that changes in coal reservoir permeability are researched, in particular, the accurate determination of variations in the coal matrix caused by CO2 replacing CH4 at different gas saturation conditions. Based on the surface free energy, the extended Langmuir isothermal adsorption model, combined with CO2 replacing CH4 in experimental trials, and calling on the more general principles and characteristics of the field, mathematical models describing the coal matrix as it undergoes different processes such as CO2 injection and desorption were established. Combined with laboratory data about CO2 replacement under different methane saturation conditions, a law governing the variations in coal matrix CO2 replacement under different methane gas saturation conditions was obtained. The results showed that： in the injection process, the coal matrix expansion rate caused by CO2 or CH4 was exponentially increased with the CO2 pressure increase, the expansion caused by CO2 was far greater than the expansion caused by CH4 in the desorption process, the coal matrix shrinkage caused by CO2 or CH4 was exponentially increased with the pressure decrease, the shrinkage caused by CO2 was larger than the shrinkage caused by CH4 under the same pressure and different gas saturation, the total shrinkage in the desorption process in the coal matrix was greater than the total expansion in the injection process. At higher gas saturations, the total coal matrix shrinkage volume exceeded the total expansion corresponding to pressure points higher in the desorption process.
基金fully sponsored by the Ministry of Education of Malaysia and Universiti Sains Malaysia through LRGS-USM Nano MITe Grant (203/PJKIMIA/6720009)
文摘The world is currently facing the challenges of global warming and climate change. Numerous efforts have been taken to mitigate CO2 emission, among which is the use of solid sorbents for CO2 capture. In this work, Li4SiO4 was synthesised via a sol-gel method using lithium nitrate （LiNO3） and tetraethylorthosilicate （SiC8H20O4） as precursors. A parametric study of Li：Si molar ratio （1-5）, calcination temperature （600-800℃） and calcination time （1-8 h） were conducted during sorbent synthesis. Calcination temperature （700-800℃） and carbonation temperature （500-700℃） during CO2 sorption activity were also varied to confirm the optimum operating temperature. Sorbent with the highest CO2 sorption capacity was finally introduced to several cyclic tests to study the durability of the sorbent through 10 cycles of CO2 sorption-desorption test. The results showed that the calcination temperature of 800℃ and carbonation temperature of 700℃ were the best operating temperatures, with CO2 sorption capacity of 7.95 mmol CO2·（g sorbent）^-1 （93% of the theoretical yield）. Throughout the ten cyclic processes, CO2 sorption capacity of the sorbent had dropped approximately 16.2% from the first to the tenth cycle, which was a reasonable decline. Thus, it was concluded that Li4SiO4 is a potential CO2 solid sorbent for high temperature CO2 capture activity.
基金Supported by the National Science and Engineering Research Committee of Canada (No213327)
文摘The photochemical mineralization of dissolved organic carbon(DOC) to dissolved inorganic carbon(DIC) is a key process in carbon cycling.Using a Suntest CPS solar simulator,Suwannee River humic acid(SRHA) was photooxidated to examine the effects of O2 levels,the wavelength of incident light,and the concentration of Fe on the photoproduction of DIC.Increasing the O2 abundance enhanced photodegradation of SRHA.The rate of DIC photoproduction under air saturation in the first 24 h(4.40 μmol/(L h)) was increased by a factor of 1.56 under O2 saturation,but fell by only 36% under N2 saturation.To evaluate the relative importance of UV-B,UV-A,and visible radiation in the photodegradation,we examined the above process using Mylar-d films and UF-3 and UF-4 plexiglass filters.The results indicated that the UV-B,UV-A and visible wavelengths accounted for 31.8%,32.6% and 25.6%,respectively,of DIC production with simulated sunlight irradiation.The above results also indicated that photoproduction of DIC could take place in natural water at depths greater than those that UV light can reach.When 20 μmol/L desferrioxamine mesylate(DFOM,a strong Fe complexing ligand) was added,the rate of DIC photoproduction fell to 55.6% that of the original SRHA samples with 5.46 μmol/L Fe.
文摘AIM: To characterize the profiles of alveolar hypoventilation during colonoscopies performed under sedoanalgesia with a combination of alfentanil and either midazolam or propofol. METHODS: Consecutive patients undergoing routine colonoscopy were randomly assigned to sedation with either propofol or midazolam in an open-labeled design using a titration scheme. All patients received 4 μg/kg per body weight alfentanil for analgesia and 3 L of supplemental oxygen. Oxygen saturation (SpO 2 ) was measured by pulse oximetry (POX), and capnography (PcCO 2 ) was continuously measured using a combined dedicated sensor at the ear lobe. Instances of apnea resulting in measures such as stimulation of the patient, a chin lift, a mask maneuver, or withholding of sedation were recorded. PcCO 2 values (as a parameter of sedation-induced hypoventilation) were compared between groups at the following distinct time points: baseline, maximal rise, termination of the procedure and 5 min after termination of the procedure. The number of patients in both study groups who regained baseline PcCO 2 values (± 1.5 mmHg) five minutes after the procedure was determined.RESULTS: A total of 97 patients entered this study. The data from 14 patients were subsequently excluded for clinical procedure-related reasons or for technical problems. Therefore, 83 patients (mean age 62 ± 13 years) were successfully randomized to receive propofol (n = 42) or midazolam (n = 41) for sedation. Most of the patients were classified as American Society of Anesthesiologists (ASA) Ⅱ [16 (38%) in the midazolam group and 15 (32%) in the propofol group] and ASA Ⅲ [14 (33%) and 13 (32%) in the midazolam and propofol groups, respectively]. A mean dose of 5 (4-7) mg of Ⅳ midazolam and 131 (70-260) mg of Ⅳ propofol was used during the procedure in the corresponding study arms. The mean SpO 2 at baseline (%) was 99 ± 1 for the midazolam group and 99 ± 1 for the propofol group. No cases of hypoxemia (SpO 2 < 85%) or apnea were recorded. However, an increase in PcCO 2 that indicated alveolar hypoventilation occurred in both groups after administration of the first drug and was not detected with pulse oximetry alone. The mean interval between the initiation of sedation and the time when the PcCO 2 value increased to more than 2 mmHg was 2.8 ± 1.3 min for midazolam and 2.8 ± 1.1 min for propofol. The mean maximal rise was similar for both drugs: 8.6 ± 3.7 mmHg for midazolam and 7.4 ± 3.2 mmHg for propofol. Five minutes after the end of the procedure, the mean difference from the baseline values was significantly lower for the propofol treatment compared with midazolam (0.9 ± 3.0 mmHg vs 4.3 ± 3.7 mmHg, P = 0.0000169), and significantly more patients in the propofol group had regained their baseline value ± 1.5 mmHg (32 of 41vs 12 of 42,P = 0.0004). CONCLUSION: A significantly higher number of patients sedated with propofol had normalized PcCO 2 values five minutes after sedation when compared with patients sedated with midazolam.
