The Experts below are selected from a list of 47268 Experts worldwide ranked by ideXlab platform
Feng Liu - One of the best experts on this subject based on the ideXlab platform.
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quantifying Temperature compensation of bicoid gradients with a fast t tunable microfluidic device
Biophysical Journal, 2020Co-Authors: Hongcun Zhu, Yong Cui, Chunxiong Luo, Feng LiuAbstract:As a reaction-diffusion system strongly affected by Temperature, early fly embryos surprisingly show highly reproducible and accurate developmental patterns during embryogenesis under Temperature perturbations. To reveal the underlying Temperature compensation mechanism, it is important to overcome the challenge in quantitative imaging on fly embryos under Temperature perturbations. Inspired by microfluidics Generating Temperature steps on fly embryos, here we design a microfluidic device capable of ensuring the normal development of multiple fly embryos as well as achieving real-time Temperature control and fast Temperature switches for quantitative live imaging with a home-built two-photon microscope. We apply this system to quantify the Temperature compensation of the morphogen Bicoid (Bcd) gradient in fly embryos. The length constant of the exponential Bcd gradient reaches the maximum at 25°C within the measured Temperatures of 18-29°C and gradually adapts to the corresponding value at new Temperatures upon a fast Temperature switch. The relaxation time of such an adaptation becomes longer if the Temperature is switched in a later developmental stage. This age-dependent Temperature compensation could be explained if the traditional synthesis-diffusion-degradation model is extended to incorporate the dynamic change of the parameters controlling the formation of Bcd gradients.
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quantifying Temperature compensation of bicoid gradients with a fast t tunable microfluidic device
bioRxiv, 2020Co-Authors: Hongcun Zhu, Yong Cui, Chunxiong Luo, Feng LiuAbstract:As a reaction-diffusion system strongly affected by Temperature, the early fly embryos surprisingly show highly reproducible and accurate developmental patterns during embryogenesis under Temperature perturbations. To reveal the underlying Temperature compensation mechanism, it is important to overcome the challenge in quantitative imaging on fly embryos under Temperature perturbations. Inspired by a microfluidics Generating Temperature steps on fly embryos, here we design a microfluidic device capable of ensuring the normal development of multiple fly embryos as well as achieving real-time Temperature control and fast Temperature jumps for quantitative live imaging with a home-built two-photon microscope. We apply this system to quantify the Temperature compensation of the morphogen Bicoid (Bcd) gradient in fly embryos. The length constant of the exponential Bcd gradient reaches the maximum at 25 {degrees}C within the measured Temperatures of 18-29 {degrees}C and gradually adapts to the corresponding value at new Temperatures upon a fast Temperature switch. Such an adaption decreases to a less degree if Temperature is switched in a later developmental stage. This age-dependent Temperature compensation could not be explained with the traditional synthesis-diffusion-degradation (SDD) model assuming the static parameters but an extended SDD model incorporating the dynamic change of the parameters controlling the formation of Bcd gradients. SIGNIFICANCEThermal robustness is important for biological systems experiencing Temperature fluctuations. To reveal the Temperature compensation mechanism, the fruit fly embryo is an ideal model system. It is intriguing how the early fly embryo achieves highly reproducible and accurate patterning despite it is a reaction-diffusion system strongly affected by Temperature. However, it has been challenging to quantitatively measure the developmental patterns in fly embryos under Temperature perturbations. To overcome this problem, we construct a fast Temperature tunable microfluidic device for fly embryos. Combining quantitative imaging with this device and mathematical modeling, we successfully quantify the Temperature response of the morphogen Bicoid (Bcd) gradient and reveal that the Temperature compensation for the Bcd gradient is stronger in the later developmental stage.
Jingming Dong - One of the best experts on this subject based on the ideXlab platform.
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experimental investigation on low Temperature thermal energy driven steam ejector refrigeration system for cooling application
Applied Thermal Engineering, 2017Co-Authors: Weining Wang, Jingming Dong, Mengqi Yu, He Song, Celue LiAbstract:Abstract In recent years, ejector refrigeration has been a hot topic for research because it can utilize low-grade energy such as solar energy or industrial waste heat. Even more importantly, it uses the most environmentally friendly substance, water, as the working fluid. According to the literatures, the utilization of the thermal energy from a low-Temperature heat source below 80 °C is a considerable challenge for the steam ejector refrigeration system. In this paper, an experimental prototype of the steam ejector refrigeration system was designed and built up. Three ejectors with a same nozzle for the primary nozzle and three different constant-area sections were designed and fabricated. The effects of the operating Temperatures, the nozzle exit position (NXP) and the area ratio of the ejector ( AR ) on the working performance of the steam ejector were investigated. The Generating Temperature is ranged from 40 °C to 70 °C. The experimental results show that a steam ejector can operate successfully for a certain configuration size of the steam ejector with a Generating Temperature ranging from 40 °C to 70 °C and an evaporating Temperature of 15 °C. The results of this investigation provided a better understanding for the cooling application of the steam ejector refrigeration system powered by low-Temperature heat source. It demonstrates that the steam ejector refrigeration system is a very promising alternative to the absorption refrigeration system, when the heat source Temperature is lower than 80 °C.
Hongcun Zhu - One of the best experts on this subject based on the ideXlab platform.
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quantifying Temperature compensation of bicoid gradients with a fast t tunable microfluidic device
Biophysical Journal, 2020Co-Authors: Hongcun Zhu, Yong Cui, Chunxiong Luo, Feng LiuAbstract:As a reaction-diffusion system strongly affected by Temperature, early fly embryos surprisingly show highly reproducible and accurate developmental patterns during embryogenesis under Temperature perturbations. To reveal the underlying Temperature compensation mechanism, it is important to overcome the challenge in quantitative imaging on fly embryos under Temperature perturbations. Inspired by microfluidics Generating Temperature steps on fly embryos, here we design a microfluidic device capable of ensuring the normal development of multiple fly embryos as well as achieving real-time Temperature control and fast Temperature switches for quantitative live imaging with a home-built two-photon microscope. We apply this system to quantify the Temperature compensation of the morphogen Bicoid (Bcd) gradient in fly embryos. The length constant of the exponential Bcd gradient reaches the maximum at 25°C within the measured Temperatures of 18-29°C and gradually adapts to the corresponding value at new Temperatures upon a fast Temperature switch. The relaxation time of such an adaptation becomes longer if the Temperature is switched in a later developmental stage. This age-dependent Temperature compensation could be explained if the traditional synthesis-diffusion-degradation model is extended to incorporate the dynamic change of the parameters controlling the formation of Bcd gradients.
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quantifying Temperature compensation of bicoid gradients with a fast t tunable microfluidic device
bioRxiv, 2020Co-Authors: Hongcun Zhu, Yong Cui, Chunxiong Luo, Feng LiuAbstract:As a reaction-diffusion system strongly affected by Temperature, the early fly embryos surprisingly show highly reproducible and accurate developmental patterns during embryogenesis under Temperature perturbations. To reveal the underlying Temperature compensation mechanism, it is important to overcome the challenge in quantitative imaging on fly embryos under Temperature perturbations. Inspired by a microfluidics Generating Temperature steps on fly embryos, here we design a microfluidic device capable of ensuring the normal development of multiple fly embryos as well as achieving real-time Temperature control and fast Temperature jumps for quantitative live imaging with a home-built two-photon microscope. We apply this system to quantify the Temperature compensation of the morphogen Bicoid (Bcd) gradient in fly embryos. The length constant of the exponential Bcd gradient reaches the maximum at 25 {degrees}C within the measured Temperatures of 18-29 {degrees}C and gradually adapts to the corresponding value at new Temperatures upon a fast Temperature switch. Such an adaption decreases to a less degree if Temperature is switched in a later developmental stage. This age-dependent Temperature compensation could not be explained with the traditional synthesis-diffusion-degradation (SDD) model assuming the static parameters but an extended SDD model incorporating the dynamic change of the parameters controlling the formation of Bcd gradients. SIGNIFICANCEThermal robustness is important for biological systems experiencing Temperature fluctuations. To reveal the Temperature compensation mechanism, the fruit fly embryo is an ideal model system. It is intriguing how the early fly embryo achieves highly reproducible and accurate patterning despite it is a reaction-diffusion system strongly affected by Temperature. However, it has been challenging to quantitatively measure the developmental patterns in fly embryos under Temperature perturbations. To overcome this problem, we construct a fast Temperature tunable microfluidic device for fly embryos. Combining quantitative imaging with this device and mathematical modeling, we successfully quantify the Temperature response of the morphogen Bicoid (Bcd) gradient and reveal that the Temperature compensation for the Bcd gradient is stronger in the later developmental stage.
B J Huang - One of the best experts on this subject based on the ideXlab platform.
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development of an ejector cooling system with thermal pumping effect
International Journal of Refrigeration-revue Internationale Du Froid, 2006Co-Authors: B J Huang, S H LeeAbstract:Abstract This paper presents a feasibility study of an ejector cooling system (ECS) that utilizes a multi-function generator (MFG) to eliminate the mechanical pump. The MFG serves as both a pump and a vapor generator. The MFG is designed based on the pressure equilibration between high and low pressures through heating and cooling process. In this design, an ECS that contains no moving components and is entirely powered by heat can be practicable. A prototype using refrigerant R141b as working fluid was constructed and tested in the present study. The experimental results showed that the system coefficient of performance (COP o ) was 0.218 and the cooling capacity was 0.786 kW at Generating Temperature ( T G ) 90 °C, condensing Temperature ( T C ) 32.4 °C and evaporating Temperature ( T E ) 8.2 °C. While taking into account the extra heat needed for the MFG operation, the total coefficient of performance (COP t ) is 0.185. It is shown that a continuous operation for the generation of cooling effect in an ECS with MFG can be achieved. This cooling machine can be very reliable since there is no moving part.
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collector selection for solar ejector cooling system
Solar Energy, 2001Co-Authors: B J Huang, V A Petrenko, Ya I Samofatov, N A ShchetininaAbstract:The performance of a solar ejector cooling system is simulated using three different collectors: a conventional flat plate collector, a high efficiency flat plate collector and a vacuum-tube collector. It is shown that with the proper selection of the Generating Temperature an optimum COP can be achieved. The solar ejector cooling system using the single-glazed solar collector with selective surface and an enhanced air insulating layer can be most economical when operated at the optimum Generating Temperature of the ejector cooling machine. In this case, the solar system cost is around 1 USD per watt of cooling capacity for air conditioning applications.
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a solar ejector cooling system using refrigerant r141b
Solar Energy, 1998Co-Authors: B J Huang, V A Petrenko, J.m. Chang, K B ZhukAbstract:Abstract A high-performance solar ejector cooling system using R141b as the working fluid was developed. We obtain experimentally a COP of 0.5 for a single-stage ejector cooling system at a Generating Temperature of 90°C, condensing Temperature of 28°C, and an evaporating Temperature 8°C. For solar cooling application, an optimum overall COP can be obtained around 0.22 at a Generating Temperature of 95°C, evaporating Temperature of 8°C and solar radiation at 700 W m −2 .
Guangming Chen - One of the best experts on this subject based on the ideXlab platform.
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Experimental study on an absorption refrigeration system at low Temperatures
International Journal of Thermal Sciences, 2007Co-Authors: Yijian He, Guangming ChenAbstract:Abstract The heat-driven auto-cascade absorption refrigeration cycle can be used at low Temperatures, and a novel auto-cascade absorption refrigeration system is proposed to gain better performances with a refrigerating Temperature as low as −50 °C. The new system uses a mixture of R23 + R32 + R134a/DMF as its working pair and its characteristic study is carried out under different operational conditions. It has successfully obtained a refrigerating Temperature of −47.2 °C under the Generating Temperature of 163 °C. This refrigerating Temperature is far lower than that of a traditional absorption refrigeration system with the same working pair, and it is also lower than that of an auto-cascade absorption refrigeration system using R32 + R134a/DMF as its working pair. From the experimental results, it is clearly seen that this new system shows a rapider lowering rate of refrigerating Temperature than that of an auto-cascade absorption refrigeration system using R23 + R134a/DMF as its working pair. The results of experimental analyses imply that this new absorption refrigeration system can be used in the deep-freezing as low as −50 °C by utilizing low-potential thermal power. Its potential of industrial application might be greater than that of an auto-cascade absorption refrigeration system using R23 + R134a/DMF as its working pair in the future.