The Experts below are selected from a list of 12 Experts worldwide ranked by ideXlab platform

Charlotte Helfrichforster - One of the best experts on this subject based on the ideXlab platform.

  • pigment dispersing factor pdf has different effects on drosophila s circadian clocks in the accessory medulla and in the dorsal brain
    Journal of Biological Rhythms, 2008
    Co-Authors: Corinna Wulbeck, Eva Grieshaber, Charlotte Helfrichforster
    Abstract:

    The neuropeptide pigment-dispersing factor (PDF) is a key transmitter in the circadian clock of Drosophila melanogaster. Here we studied the rhythmic behavior of neural mutants with modified arborizations of the large PDF neurons. In sine oculis1 (so1) mutants we found a higher density of PDF fibers in the fly's pacemaker center, the accessory medulla. These flies exhibited a significantly longer period (24.6 h) than control flies. When PDF levels were elevated to very high levels in the dorsal brain as true for somda mutants and small optic lobes;so1 double mutants (sol1;so 1), a short-period Component Split off the long period in behavioral rhythmicity. The short period became shorter the higher the amount of PDF in this brain region and reached a value of ~21 h. The period alterations were clearly dependent on PDF, because so1;Pdf 01 and somda;Pdf 01 double mutants showed a single free-running Component with a period similar to Pdf 01 mutants (~22.5 h) and significantly longer than the short period of ...

Wei Sun - One of the best experts on this subject based on the ideXlab platform.

  • Modeling/Simulation of the Dividing Wall Column by Using the Rigorous Model
    MDPI AG, 2019
    Co-Authors: Chi Zhai, Qinjun Liu, Jose A. Romagnoli, Wei Sun
    Abstract:

    Dividing wall column (DWC) is an atypical distillation column with an internal, vertical WE partition wall that effectively accommodates two conventional distillation columns into one to improve the thermodynamic efficiency. In previous studies, different equivalent models by combining conventional columns are adopted to approximate the DWC modeling, which may not well describe the integration of the DWC; moreover, the computational cost increases when multiple columns are implemented to represent one DWC. In this paper, a rigorous mathematical model is proposed based on the mass balance, the energy and phase equilibrium of the DWC, where decision variables and state variables are equally treated. The model was developed in the general process modeling system (gPROMS). Based on the rigorous model, the influences of liquid Split ratio and vapor Split ratio are discussed, and it is shown that the heat duty is sensitive to changes on the liquid and vapor Split ratio. Inappropriate liquid and vapor Split ratio will increase the mixing effects at both ends of the dividing wall, and adversely affect the thermodynamic efficiency. Hence, the degree of mixing is defined to characterize the column efficiency. Furthermore, the middle Component Split ratio at the top of the pre-fractionator has an optimal point for better energy saving with certain liquid and vapor Split ratios, and can be used as an indicator for the energy performance. Finally, the model was tested and validated against literature data by using the ternary benzene–toluene–xylene mixture system as a case study

Corinna Wulbeck - One of the best experts on this subject based on the ideXlab platform.

  • pigment dispersing factor pdf has different effects on drosophila s circadian clocks in the accessory medulla and in the dorsal brain
    Journal of Biological Rhythms, 2008
    Co-Authors: Corinna Wulbeck, Eva Grieshaber, Charlotte Helfrichforster
    Abstract:

    The neuropeptide pigment-dispersing factor (PDF) is a key transmitter in the circadian clock of Drosophila melanogaster. Here we studied the rhythmic behavior of neural mutants with modified arborizations of the large PDF neurons. In sine oculis1 (so1) mutants we found a higher density of PDF fibers in the fly's pacemaker center, the accessory medulla. These flies exhibited a significantly longer period (24.6 h) than control flies. When PDF levels were elevated to very high levels in the dorsal brain as true for somda mutants and small optic lobes;so1 double mutants (sol1;so 1), a short-period Component Split off the long period in behavioral rhythmicity. The short period became shorter the higher the amount of PDF in this brain region and reached a value of ~21 h. The period alterations were clearly dependent on PDF, because so1;Pdf 01 and somda;Pdf 01 double mutants showed a single free-running Component with a period similar to Pdf 01 mutants (~22.5 h) and significantly longer than the short period of ...

Chi Zhai - One of the best experts on this subject based on the ideXlab platform.

  • Modeling/Simulation of the Dividing Wall Column by Using the Rigorous Model
    MDPI AG, 2019
    Co-Authors: Chi Zhai, Qinjun Liu, Jose A. Romagnoli, Wei Sun
    Abstract:

    Dividing wall column (DWC) is an atypical distillation column with an internal, vertical WE partition wall that effectively accommodates two conventional distillation columns into one to improve the thermodynamic efficiency. In previous studies, different equivalent models by combining conventional columns are adopted to approximate the DWC modeling, which may not well describe the integration of the DWC; moreover, the computational cost increases when multiple columns are implemented to represent one DWC. In this paper, a rigorous mathematical model is proposed based on the mass balance, the energy and phase equilibrium of the DWC, where decision variables and state variables are equally treated. The model was developed in the general process modeling system (gPROMS). Based on the rigorous model, the influences of liquid Split ratio and vapor Split ratio are discussed, and it is shown that the heat duty is sensitive to changes on the liquid and vapor Split ratio. Inappropriate liquid and vapor Split ratio will increase the mixing effects at both ends of the dividing wall, and adversely affect the thermodynamic efficiency. Hence, the degree of mixing is defined to characterize the column efficiency. Furthermore, the middle Component Split ratio at the top of the pre-fractionator has an optimal point for better energy saving with certain liquid and vapor Split ratios, and can be used as an indicator for the energy performance. Finally, the model was tested and validated against literature data by using the ternary benzene–toluene–xylene mixture system as a case study

Shoujian Zhang - One of the best experts on this subject based on the ideXlab platform.

  • Factors Affecting the Capital Cost of Prefabrication—A Case Study of China
    MDPI AG, 2017
    Co-Authors: Hong Xue, Shoujian Zhang
    Abstract:

    As a sustainable construction method, prefabrication has become popular in many nations. However, there are many challenges for prefabrication, especially in terms of cost. Previous studies have revealed that higher capital cost was the most important barrier to the implementation of prefabrication. Thus, the objective of this study is to explore and evaluate the critical factors affecting the capital cost of prefabrication and examine how cost management may be affected by the “experience”, “corporate responsibility”, and “participant function” as a fix independent factors. To achieve the research objective, semi-structured interviews were conducted with 11 experts for the development of the questionnaire. Then, a questionnaire survey was conducted to investigate the significance of 49 factors related to prefabrication capital cost. The survey results revealed that “Specification and standards for prefabricated building design”, “Related experience of manager”, and “Rationality of precast Component Split” were the most critical factors. In addition, “experience”, “corporate responsibility”, and “participant function” had significant impact on the evaluation of capital cost factors. The findings can facilitate developing a benchmark framework for exploring the factors affecting the capital cost of prefabrication in China