Objective: Lumbar-dural combination is the most common anesthesia method, depending on the rate of injection, and thus affecting the patients anesthesia and hemodynamics. Methods: All of the 120 subjects in this surve...Objective: Lumbar-dural combination is the most common anesthesia method, depending on the rate of injection, and thus affecting the patients anesthesia and hemodynamics. Methods: All of the 120 subjects in this survey underwent surgery, using waist-hard-soft anesthesia, during the hospital stay of our hospital.[September 2020, August 2021], grouped by lottery, group A (n40), B (n40) at speeds of 10s, 15s, 20s and C (n40), respectively. The anesthesia effect of the three groups was evaluated, and the main parameters selected were: maximum block plane, T6 block time, anesthesia effect, action block, etc., and the patient was monitored for blood dynamics.(1) Comparison: Group A (maximum block plane between groups) and T6 block (T6 block) (no significant difference between groups) (no significant difference between groups) (maximum block plane 8.28 ± 1.26 min, T6) (no significant difference between groups) were significantly better than Group A (8.28 ± 1.26 min, T6 block 7.47 ± 1.45 min), P 0.05. (2) Anesthesia (Group A 97.50%, Group B 100.00%, Group C) anesthesia block (Group A 2.540.58), Group B (Bromage) score (2.720.39), Group C (Bromage) (2.63 + 0.64), and Group C (Bromage) (2.63 + 0.64).(3) Three groups of patients before anesthesia heart rate, arterial pressure, oxygen saturation hemodynamic index level is similar, there is no significant statistical significance (P> 0.05), the index after anesthesia level changes larger, and there are significant statistical significance (P 0.05), the lowest in heart rate, the highest in arterial pressure and oxygen saturation group C, p 0.05. Conclusion: In clinical practice, hard lumbar puncture anesthesia should maintain the anesthesia rate of 15 seconds or 20 seconds, while the hemodynamic effect is at least within 20 seconds, and the optimal injection rate can be determined according to the patients condition.展开更多
Thin wall samples of high density polyethylene （HDPE） were prepared via injection molding with different injection speeds ranging from 100 mm/s to 1200 mm/s. A significant decrease in the tensile strength and Young...Thin wall samples of high density polyethylene （HDPE） were prepared via injection molding with different injection speeds ranging from 100 mm/s to 1200 mm/s. A significant decrease in the tensile strength and Young＇s modulus was observed with increasing injection speed. In order to investigate the mechanism behind this decrease, the orientation, molecular weight, molecular weight distribution, melt flow rate, crystallinity and crystal morphology of HDPE were characterized using two-dimensional wide-angle X-ray diffraction （2D-WAXD）, gel permeation chromatography （GPC）, capillary rheometry and differential scanning calorimetry （DSC）, respectively. It is demonstrated that the orientation, molecular weight, molecular weight distribution, melt flow rate and crystallinity have no obvious change with increasing injection speed. Nevertheless, the content of extended chain crystals or large folded chain crystals was found to decrease with increasing injection speed. Therefore, it is concluded that the decrease in tensile properties is mainly contributed by the reduced content of extended chain crystals or large folded chain crystals. This study provides industry with valuable information for the application of high speed injection molding.展开更多
In the process of oilfield water injection volume of injection allocation often appear with the pump displacement situation does not match, the widespread adoption of stator frequency technology allows the pump displa...In the process of oilfield water injection volume of injection allocation often appear with the pump displacement situation does not match, the widespread adoption of stator frequency technology allows the pump displacement and volume of injection allocation phase matching. But the technology in pump class load application speed range is limited, there is still a reflux valve control blind area,＂ turn off undead＂ problem. ＂ One-for-several＂ rotor frequency Technique in water injection station application, solved the control blind area problem, the full realization of the variable frequency close return voltage injection, at the same time, the successful implementation of the slip power efficient feedback. Stable water injection pressure of the system, and the electric energy is saved, satisfy the oilfield high efficiency, fine water needs, has a high application value.展开更多
Based on the oil,gas and water distribution characteristics of Khasib reservoir in Halfaya oilfield,Iraq,a core displacement experiment is designed to evaluate the influence of different displacement methods and displ...Based on the oil,gas and water distribution characteristics of Khasib reservoir in Halfaya oilfield,Iraq,a core displacement experiment is designed to evaluate the influence of different displacement methods and displacement parameters on oil displacement efficiency.The research shows that,in the displacement method with water injected from the edge of the reservoir,early depletion production is conducive to the elastic expansion of the gas cap,forming the three-dimensional displacement of"upper pressure and lower pushing",and the oil displacement effect is good.When gas injection at the top and water injection at the edge are used for synergistic displacement,the injection timing has different influences on the oil displacement effects of high and low parts.Considering the overall oil displacement efficiency,the injection pressure should be greater than the bubble point pressure of crude oil.Two displacement methods are recommended with the reasonable injection time at 20–25 MPa.The injection speed has the same influence on different injection media.Appropriately reducing the injection speed is conducive to the stability of the displacement front,delaying the breakthrough of injection media and improving the oil displacement effect.The reasonable injection rate of water flooding is 0.075 mL/min,the reasonable injection rates of water and gas are 0.15 mL/min and 0.10 mL/min,respectively in gas-water synergistic displacement.Gas-water synergistic displacement is conducive to the production of crude oil at high position,and has crude oil recovery 5.0%–14.8%higher than water flooding from the edge,so it is recommended as the development mode of Khasib reservoir at the middle and late stages.展开更多
This paper investigates the effect of intake port configuration on the swirl that is generated within a direct injection(D.I.) diesel engine. The in-cylinder flow characteristics are known to have significant effects ...This paper investigates the effect of intake port configuration on the swirl that is generated within a direct injection(D.I.) diesel engine. The in-cylinder flow characteristics are known to have significant effects on fuel-air mixing, combustion, and emissions. To clarify how to intensify the swirl flow, a swirl control valve(SCV) and a bypass were selected as design parameters for enhancing the swirl flow. The optimal intake port shape was also chosen as a parameter needed to efficiently generate a high swirl ratio. The results revealed that a key factor in generating a high swirl ratio was to control the intake airflow direction passing through the intake valve seat. Further, the swirl intensity was influenced by changing the distance between the helical and tangential ports, and the swirl flow was changed by the presence of a bypass near the intake valve seat. Additionally, the effect of intake port geometry on the in-cylinder flow field was investigated by using a laser sheet visualization method. The experimental results showed a correlation of swirl ratio and mass flow rate. In addition, we found that employing the bypass was an effective method to increase swirl ratio without sacrificing mass flow rate.展开更多
文摘Objective: Lumbar-dural combination is the most common anesthesia method, depending on the rate of injection, and thus affecting the patients anesthesia and hemodynamics. Methods: All of the 120 subjects in this survey underwent surgery, using waist-hard-soft anesthesia, during the hospital stay of our hospital.[September 2020, August 2021], grouped by lottery, group A (n40), B (n40) at speeds of 10s, 15s, 20s and C (n40), respectively. The anesthesia effect of the three groups was evaluated, and the main parameters selected were: maximum block plane, T6 block time, anesthesia effect, action block, etc., and the patient was monitored for blood dynamics.(1) Comparison: Group A (maximum block plane between groups) and T6 block (T6 block) (no significant difference between groups) (no significant difference between groups) (maximum block plane 8.28 ± 1.26 min, T6) (no significant difference between groups) were significantly better than Group A (8.28 ± 1.26 min, T6 block 7.47 ± 1.45 min), P 0.05. (2) Anesthesia (Group A 97.50%, Group B 100.00%, Group C) anesthesia block (Group A 2.540.58), Group B (Bromage) score (2.720.39), Group C (Bromage) (2.63 + 0.64), and Group C (Bromage) (2.63 + 0.64).(3) Three groups of patients before anesthesia heart rate, arterial pressure, oxygen saturation hemodynamic index level is similar, there is no significant statistical significance (P> 0.05), the index after anesthesia level changes larger, and there are significant statistical significance (P 0.05), the lowest in heart rate, the highest in arterial pressure and oxygen saturation group C, p 0.05. Conclusion: In clinical practice, hard lumbar puncture anesthesia should maintain the anesthesia rate of 15 seconds or 20 seconds, while the hemodynamic effect is at least within 20 seconds, and the optimal injection rate can be determined according to the patients condition.
基金supported by the National Natural Science Foundation of China(No.51073111)
文摘Thin wall samples of high density polyethylene （HDPE） were prepared via injection molding with different injection speeds ranging from 100 mm/s to 1200 mm/s. A significant decrease in the tensile strength and Young＇s modulus was observed with increasing injection speed. In order to investigate the mechanism behind this decrease, the orientation, molecular weight, molecular weight distribution, melt flow rate, crystallinity and crystal morphology of HDPE were characterized using two-dimensional wide-angle X-ray diffraction （2D-WAXD）, gel permeation chromatography （GPC）, capillary rheometry and differential scanning calorimetry （DSC）, respectively. It is demonstrated that the orientation, molecular weight, molecular weight distribution, melt flow rate and crystallinity have no obvious change with increasing injection speed. Nevertheless, the content of extended chain crystals or large folded chain crystals was found to decrease with increasing injection speed. Therefore, it is concluded that the decrease in tensile properties is mainly contributed by the reduced content of extended chain crystals or large folded chain crystals. This study provides industry with valuable information for the application of high speed injection molding.
文摘In the process of oilfield water injection volume of injection allocation often appear with the pump displacement situation does not match, the widespread adoption of stator frequency technology allows the pump displacement and volume of injection allocation phase matching. But the technology in pump class load application speed range is limited, there is still a reflux valve control blind area,＂ turn off undead＂ problem. ＂ One-for-several＂ rotor frequency Technique in water injection station application, solved the control blind area problem, the full realization of the variable frequency close return voltage injection, at the same time, the successful implementation of the slip power efficient feedback. Stable water injection pressure of the system, and the electric energy is saved, satisfy the oilfield high efficiency, fine water needs, has a high application value.
基金Supported by the Scientific Research and Technology Development Project of CNPC(2019D-4410)。
文摘Based on the oil,gas and water distribution characteristics of Khasib reservoir in Halfaya oilfield,Iraq,a core displacement experiment is designed to evaluate the influence of different displacement methods and displacement parameters on oil displacement efficiency.The research shows that,in the displacement method with water injected from the edge of the reservoir,early depletion production is conducive to the elastic expansion of the gas cap,forming the three-dimensional displacement of"upper pressure and lower pushing",and the oil displacement effect is good.When gas injection at the top and water injection at the edge are used for synergistic displacement,the injection timing has different influences on the oil displacement effects of high and low parts.Considering the overall oil displacement efficiency,the injection pressure should be greater than the bubble point pressure of crude oil.Two displacement methods are recommended with the reasonable injection time at 20–25 MPa.The injection speed has the same influence on different injection media.Appropriately reducing the injection speed is conducive to the stability of the displacement front,delaying the breakthrough of injection media and improving the oil displacement effect.The reasonable injection rate of water flooding is 0.075 mL/min,the reasonable injection rates of water and gas are 0.15 mL/min and 0.10 mL/min,respectively in gas-water synergistic displacement.Gas-water synergistic displacement is conducive to the production of crude oil at high position,and has crude oil recovery 5.0%–14.8%higher than water flooding from the edge,so it is recommended as the development mode of Khasib reservoir at the middle and late stages.
基金supported by the research fund of Hanyang University(HY-2012-P)
文摘This paper investigates the effect of intake port configuration on the swirl that is generated within a direct injection(D.I.) diesel engine. The in-cylinder flow characteristics are known to have significant effects on fuel-air mixing, combustion, and emissions. To clarify how to intensify the swirl flow, a swirl control valve(SCV) and a bypass were selected as design parameters for enhancing the swirl flow. The optimal intake port shape was also chosen as a parameter needed to efficiently generate a high swirl ratio. The results revealed that a key factor in generating a high swirl ratio was to control the intake airflow direction passing through the intake valve seat. Further, the swirl intensity was influenced by changing the distance between the helical and tangential ports, and the swirl flow was changed by the presence of a bypass near the intake valve seat. Additionally, the effect of intake port geometry on the in-cylinder flow field was investigated by using a laser sheet visualization method. The experimental results showed a correlation of swirl ratio and mass flow rate. In addition, we found that employing the bypass was an effective method to increase swirl ratio without sacrificing mass flow rate.
