Plain concrete plate and fiber concrete plate subjected to temperature drop load were analyzed on stochastic finite element method (FEM).It is found that fibers can enhance concrete ability to resist tem- perature dro...Plain concrete plate and fiber concrete plate subjected to temperature drop load were analyzed on stochastic finite element method (FEM).It is found that fibers can enhance concrete ability to resist tem- perature drop load for improving concrete's fracture energy and deferring the crack process.It is found for concrete not to improve apparently its tensile strength and fracture energy is recommended to be its appraisal parameter.展开更多
An experimental study was carried out to investigate the amount of drugs loaded on microneedles. The microneedles were made with poly (lactic acid). Aqueous poly (vinyl alcohol) solutions were prepared as drug solutio...An experimental study was carried out to investigate the amount of drugs loaded on microneedles. The microneedles were made with poly (lactic acid). Aqueous poly (vinyl alcohol) solutions were prepared as drug solutions. Two drug loading approaches, i.e., dropping and dipping, were examined. It was found that capillary number is the only relevant dimensionless group for the two methods. For the dropping approach, dried drugs will spread near the bottom of a microneedle patch provided the surface tension is low. As for the dipping approach, both a single microneedle and an array of nine microneedles were examined. For a single microneedle, high capillary rises before pulling and pulling speed are two key factors to increase the drug loading volume. For an array of microneedles, the effect of capillary rise owing to the interaction between microneedles would increase the drug loading volume several times higher than a single microneedle of the same dimension.展开更多
This study explains the relationship between friction coefficient and pressure change at a range of Reynolds (21,056 - 28,574) and (0 - 1.4) solid loading ratio of two-phase flow (gas-solid) inside a circular copper p...This study explains the relationship between friction coefficient and pressure change at a range of Reynolds (21,056 - 28,574) and (0 - 1.4) solid loading ratio of two-phase flow (gas-solid) inside a circular copper pipe by using laboratory apparatus and solving the equations mathematically. An experimentally relationship of friction coefficient and pressure change with Reynolds number and flow velocity obtained also the relationship between the Solid loading ratio with friction coefficient and pressure change has been done for a Limit range of Reynolds number. It was noticed that the increase in friction coefficient and pressure change for two-phase flow was occurred when solid loading ratio increased. Also the relationship between pressure change and Reynolds number was direct proportion while the relationship between friction coefficient and Reynolds Number was inversely related.展开更多
随着风电在电力系统中占比的逐年攀升,传统机组单独承担调频任务已难以适应其需求变化。因此,风电需具备与传统电源协同调节系统频率的能力。首先,基于风电调频的快速性和火电调频的持久性,设计了一种以火电为主、风电为辅的联合一次调...随着风电在电力系统中占比的逐年攀升,传统机组单独承担调频任务已难以适应其需求变化。因此,风电需具备与传统电源协同调节系统频率的能力。首先,基于风电调频的快速性和火电调频的持久性,设计了一种以火电为主、风电为辅的联合一次调频控制策略。其次,充分考虑风电场内各机组的运行差异,提出一种基于裕度因子的功率分配策略,有效挖掘各机组的调频能力并确保其安全运行。同时,提出一种针对风电场内风机分组运行的持久备用功率再分配策略。该策略预先安排少数风电机组以低减载率的超速模式运行,当调频风机退出频率支撑后,减载风机将根据调频风机的转速,采用一种基于转速反比例因子的差异化能量分配策略,以有效弥补调频风机退出后的能量缺额,缓解频率二次跌落(secondary frequency drop,SFD)。仿真结果表明,所提策略能够实现风火联合参与一次调频,在保证经济性和可靠性的前提下,充分发掘风电调频性能,有效改善电力系统频率响应特性。展开更多
文摘Plain concrete plate and fiber concrete plate subjected to temperature drop load were analyzed on stochastic finite element method (FEM).It is found that fibers can enhance concrete ability to resist tem- perature drop load for improving concrete's fracture energy and deferring the crack process.It is found for concrete not to improve apparently its tensile strength and fracture energy is recommended to be its appraisal parameter.
文摘An experimental study was carried out to investigate the amount of drugs loaded on microneedles. The microneedles were made with poly (lactic acid). Aqueous poly (vinyl alcohol) solutions were prepared as drug solutions. Two drug loading approaches, i.e., dropping and dipping, were examined. It was found that capillary number is the only relevant dimensionless group for the two methods. For the dropping approach, dried drugs will spread near the bottom of a microneedle patch provided the surface tension is low. As for the dipping approach, both a single microneedle and an array of nine microneedles were examined. For a single microneedle, high capillary rises before pulling and pulling speed are two key factors to increase the drug loading volume. For an array of microneedles, the effect of capillary rise owing to the interaction between microneedles would increase the drug loading volume several times higher than a single microneedle of the same dimension.
文摘This study explains the relationship between friction coefficient and pressure change at a range of Reynolds (21,056 - 28,574) and (0 - 1.4) solid loading ratio of two-phase flow (gas-solid) inside a circular copper pipe by using laboratory apparatus and solving the equations mathematically. An experimentally relationship of friction coefficient and pressure change with Reynolds number and flow velocity obtained also the relationship between the Solid loading ratio with friction coefficient and pressure change has been done for a Limit range of Reynolds number. It was noticed that the increase in friction coefficient and pressure change for two-phase flow was occurred when solid loading ratio increased. Also the relationship between pressure change and Reynolds number was direct proportion while the relationship between friction coefficient and Reynolds Number was inversely related.
文摘随着风电在电力系统中占比的逐年攀升,传统机组单独承担调频任务已难以适应其需求变化。因此,风电需具备与传统电源协同调节系统频率的能力。首先,基于风电调频的快速性和火电调频的持久性,设计了一种以火电为主、风电为辅的联合一次调频控制策略。其次,充分考虑风电场内各机组的运行差异,提出一种基于裕度因子的功率分配策略,有效挖掘各机组的调频能力并确保其安全运行。同时,提出一种针对风电场内风机分组运行的持久备用功率再分配策略。该策略预先安排少数风电机组以低减载率的超速模式运行,当调频风机退出频率支撑后,减载风机将根据调频风机的转速,采用一种基于转速反比例因子的差异化能量分配策略,以有效弥补调频风机退出后的能量缺额,缓解频率二次跌落(secondary frequency drop,SFD)。仿真结果表明,所提策略能够实现风火联合参与一次调频,在保证经济性和可靠性的前提下,充分发掘风电调频性能,有效改善电力系统频率响应特性。
