The purpose of this study is to analyze the galloping characteristics of the catenary positive feeder in fluctuating wind areas considering dynamic-wind angle of attack and aerodynamic damping.Firstly,the flow field m...The purpose of this study is to analyze the galloping characteristics of the catenary positive feeder in fluctuating wind areas considering dynamic-wind angle of attack and aerodynamic damping.Firstly,the flow field model of the catenary positive feeder was established,the fluctuating wind field was simulated by Davenport wind power spectrum and linear filtering method,and the wind speed at inlet in calculation domain was controlled by editing the profile file to simulate and calculate the aerodynamic characteristics of the positive feeder in the fluctuating wind area.Then,taking the positive feeder as the research object,the mathematical model of actual structure and the corresponding finite element model were established.By applying the wind load to the finite element model,the influence of aerodynamic damping caused by the self-movement of the positive feeder on the galloping response was analyzed,and the frequency domain characteristics of galloping displacement of the positive feeder considering aerodynamic damping were studied.Finally,the calculation method of aerodynamic damping by the Guidelines for Electrical Transmission Line Structural Loading(ASCE No.74)was used for the galloping response of the positive feeder and compared with the proposed method.The results show that when considering aerodynamic damping,the galloping amplitude of the positive feeder decreases significantly,and the first-order resonance effect on the vertical displacement and horizontal displacement decreases significantly.The galloping trajectories calculated by the two methods are consistent.Therefore,this study is of great significance to further clarify the ice-free galloping mechanism of the catenary positive feeder in violent wind areas.展开更多
In our previous study, five homologous feeder cell lines, Monkey ear skin fibroblasts （MESFs）, clonally derived fibroblasts from the MESFs （CMESFs）, monkey oviductal fibroblasts （MOFs）, monkey follicular granulo...In our previous study, five homologous feeder cell lines, Monkey ear skin fibroblasts （MESFs）, clonally derived fibroblasts from the MESFs （CMESFs）, monkey oviductal fibroblasts （MOFs）, monkey follicular granulosa fibroblast-like （MFGs） cells, monkey follicular granulosa epithelium-like （MFGEs） cells, were developed for the maintenance of rhesus embryonic stem cells （rESCs）. We found that MESFs, CMESFs, MOFs and MFGs, but not MFGEs, support the growth of rhesus embryonic stem cells. Moreover, we detected some genes that are upregulated in supportive feeder cell lines by semi-quantitative PCR. In the present study, we applied the GeneChip Rhesus Macaque Genome Array of Affymetrix Corporation to study the expression profiles of these five feeder cell lines, in purpose to find out which cytokines and signaling pathways were important in maintaining the rESCs, mRNAs of eight genes, including GREM2, bFGF, KITLG, DKK3, GREM1, AREG, SERPINF1 and LTBP1, were found to be upregulated in supportive feeder cell lines, but not in MFGE. The results indicate that many signaling pathways may play redundant roles in supporting the undifferentiated growth and maintenance of pluripotency in rESCs.展开更多
Induced pluripotent stem （iPS） cells can be derived from human somatic cells by cellular reprograrnming. This technology provides a potential source of non-controversial therapeutic ceils for tissue repair, drug dis...Induced pluripotent stem （iPS） cells can be derived from human somatic cells by cellular reprograrnming. This technology provides a potential source of non-controversial therapeutic ceils for tissue repair, drug discovery, and opportunities for studying the molecular basis of human disease. Normally, mouse embryonic fibroblasts （MEFs） are used as feeder layers in the initial derivation of iPS lines. The pur- pose of this study was to determine whether SNL fibrohlasts can be used to support the growth of human iPS cells reprogrammed from somatic cells using lentiviral expressed reprogramming factors. In our study, iPS cells expressed common pluripotency markers, dis- played human embryonic stem cells （hESCs） morphology and unmethylated promoters of NANOG and OCT4. These data demonstrate that SNL feeder cells can support the derivation and maintenance of human iPS cells.展开更多
In vitro growth and maintenance of embryonic stem (ES) cell lines derived from ICM cells of various blastocysts of 129 strain mice, the sustenance of their pluripotency and normal karyotype depend on the feeder layer ...In vitro growth and maintenance of embryonic stem (ES) cell lines derived from ICM cells of various blastocysts of 129 strain mice, the sustenance of their pluripotency and normal karyotype depend on the feeder layer of mouse embryonic fibroblasts (MEF). Compared with the feeder layer of MEF cells, medium conditioned by Buffalo rat liver cells (BRL-CM) is able to maintain pluripotency and karyo-typic normality of ES cells only in short term cell propagation. Besides, ES cells grown in BRL-CM are also capable of aggregation with 8-cell embryos of Swiss strain and develop into germ line chimaeras. Modification to the method of aggregating ES cells with early embryos by making a hole in agar layer on the top of MEF feeder cells was shown to be more convenient and efficient than the conventional microdrop method.展开更多
Because of the increasingly prominent problem of alumina content inhomogeneity in large or super-scale aluminum reduction cells,a transient numerical model for the alumina mixing process was developed for a400kA cell,...Because of the increasingly prominent problem of alumina content inhomogeneity in large or super-scale aluminum reduction cells,a transient numerical model for the alumina mixing process was developed for a400kA cell,and the relationship between the alumina content distribution and electrolyte flow field was analyzed.In the ANSYS software platform,several numerical simulation cases were presented to display the influence of the feeder configuration on the alumina mixing characteristics.The results showed that a large vortex flow of the molten electrolyte is beneficial for alumina mixing and uniform distribution in the inner areas of the vortexes.The alumina particles reach the inter-electrode zone in10?15s from the beginning of the feeding action,and the risk of early precipitation occurs in10?25s after the feeding.It was also found that a suitable grouping of feeders could reduce the content fluctuation and gradient.Therefore,a feeding on demand strategy was proposed,and the simulation results showed that although the spatial characteristics are not changed,the uniformity of the alumina content was markedly improved.展开更多
International thermonuclear experimental reactor （ITER） edge localized mode （ELM） coils are used to mitigate or suppress ELMs. The location of the coils in the vacuum vessel and behind the blankets exposes them to...International thermonuclear experimental reactor （ITER） edge localized mode （ELM） coils are used to mitigate or suppress ELMs. The location of the coils in the vacuum vessel and behind the blankets exposes them to high radiation levels and high temperatures. The feeders provide the power and cooling water for ELM coils. They are located in the chinmey ports and experience lower radiation and temperature levels. These coils and feeders work in a high magnetic field environment and are subjected to alternating electromagnetic force due to the interaction between high magnetic field and alternating current （AC） current in the coils. They are also subjected to thermal stresses due to thermal expansion. Using the ITER upper ELM coil and feeder as an example, mechanical analyses are performed to verify and optimize the updated design to enhance their structural performance. The results show that the conductor, jacket and bracket can meet the static, fatigue and crack threshold criteria. The optimization indicates that adding chamfers to the bracket can reduce the high stress of the bracket, and removing two rails can reduce the peak reaction force on the two rails arising from thermal expansion.展开更多
Two common problems for a typical Power distribution system are voltage collapse & instability. Challenge is to identify the vulnerable nodes and apply the effective corrective actions. This paper presents a proba...Two common problems for a typical Power distribution system are voltage collapse & instability. Challenge is to identify the vulnerable nodes and apply the effective corrective actions. This paper presents a probabilistic fuzzy approach to assess the node status and proposes feeder reconfiguration as a method to address the same. Feeder reconfiguration is altering the topological structures of distribution feeders by changing the open/closed states of the sectionalizing and ties switches. The solution is converge using a probabilistic fuzzy modeled solution, which defines the nodal vulnerability index (VI) as a function of node voltage and node voltage stability index and predicts nodes critical to voltage collapse. The information is further used to plan best combination of feeders from each loop in distribution system to be switched out such that the resulting configuration gives the optimal performance i.e. best voltage profile and minimal kW losses. The proposed method is tested on established radial distribution system and results are presented.展开更多
The performance of complementary feeders, running in parallel, can be significantly improved by installing static transfer switches （STSs） at critical locations. We develop the STS control logic, which transfers the...The performance of complementary feeders, running in parallel, can be significantly improved by installing static transfer switches （STSs） at critical locations. We develop the STS control logic, which transfers the critical load from the preferred feeder to the alternate feeder when a voltage sag or a fault occurs on the preferred feeder. A forced commutation technique is proposed and implemented to turn off the preferred feeders＇ thyristor, thus avoiding cross current to flow and minimizing the transfer time. Simulation results show that the forced commutation technique is more effective as compared to the recently proposed time delay technique for STS operation. Two different feeders, namely New Exchange, the preferred feeder, and Sector 1-10/2, the alternate feeder of Islamabad Electric Supply COmpany （IESCO）, Pakistan, have been selected for case studies. The software PSCAD/EMTDC professional package has been used for simulation.展开更多
AIM： To explore the possibility of human umbilical cord mesenchymal stem cells（h UCMSCs）, human umbilical vein endothelial cells（h UVECs）, human dental pulp stem cells（h DPSCs） and human periodontal ligament st...AIM： To explore the possibility of human umbilical cord mesenchymal stem cells（h UCMSCs）, human umbilical vein endothelial cells（h UVECs）, human dental pulp stem cells（h DPSCs） and human periodontal ligament stem cells（h PDLSCs） serving as feeder cells in co-culture systems for the cultivation of limbal stem cells.METHODS： Different feeder layers were cultured in Dulbecco＇s modified Eagle＇s medium（DMEM）/F12 and were treated with mitomycin C. Rabbits limbal stem cells（LSCs） were co-cultured on h UCMSCs, h UVECs, h DPSCs, h PDLSCs and NIH-3T3, and then comparative analysis were made between each group to see their respective colony-forming efficiency（CFE） assay and immunofluorescence（IPO13,CK3/12）.RESULTS： The efficiency of the four type cells in supporting the LSCs morphology and its cellular differentiation was similar to that of NIH-3T3 fibroblasts as demonstrated by the immunostaining properties analysis, with each group exhibiting a similar strong expression pattern of IPO13, but lacking CK3 and CK12 expression in terms of immunostaining. But h UCMSCs, h DPSCs and h PDLSCs feeder layers were superior in promoting colony formation potential of cells when compared to h UVECs and feedercell-free culture.CONCLUSION： hUCMSCs, hDPSCs and hPDLSCs can be a suitable alternative to conventional mouse NIH-3T3 feeder cells, so that risk of zoonotic infection can be diminished.展开更多
This paper proposes the design concept of a dynamic charging system for electric vehicles using multiple transmitter coils connected to a common radio frequency(RF)feeder driven by a pair of two power supplies.Using a...This paper proposes the design concept of a dynamic charging system for electric vehicles using multiple transmitter coils connected to a common radio frequency(RF)feeder driven by a pair of two power supplies.Using a common RF feeder for multiple transmitter coils reduces the power electronic redundancy compared to a conventional system,where each transmitter coil is individually driven by one switched-mode power supply.Currently,wireless charging of electric vehicles is recommended to operate in the frequency range of 85 kHz and beyond.In this frequency range,the signal wavelength is shorter than about 3.5 km.Therefore,a charging pad longer than several hundred meters is subject to the standing wave effect.In such a case,the voltage significantly varies along the RF feeder,resulting in a variation in the received power level when the receiver moves.Specifically,the received power significantly deteriorates when the receiver is nearby a node of the voltage standing wave.In this paper,we employ a pair of two power sources which are electrically separated by an odd-integer number of the quarter wavelength to drive the RF feeder.As a result,the voltage standing wave generated by one power source is complemented by that of the other,leading to stable received power and transmission efficiency at all the receiver’s positions along with the charging pad.Simulation results at the 85 kHz frequency band verify the output power stabilization effect of the proposed design.It is worth noting that the proposed concept can also be applied to simultaneous wireless information and power transfer(SWIPT)for passive radio frequency identification(RFID)tags by raising the operation frequency to higher industrial,scientific and medical(ISM)bands,e.g.,13.56 MHz and employing similar modulation methods as in the current RFID technology.展开更多
In China, 31 genera and 95 species of fungivorous Phlaeothripinae are recorded here, of which 7 species are newly recorded and illustrated. An illustrated identification key to the 94 species is also provided, togethe...In China, 31 genera and 95 species of fungivorous Phlaeothripinae are recorded here, of which 7 species are newly recorded and illustrated. An illustrated identification key to the 94 species is also provided, together with the information of specimens examined, and distribution of each species.展开更多
In the present study, the dynamic response of a coupled SPM-feeder-cage system under irregular waves and shear currents is analyzed. A numerical model is developed by using the commercial software Orca Flex. Hydrodyna...In the present study, the dynamic response of a coupled SPM-feeder-cage system under irregular waves and shear currents is analyzed. A numerical model is developed by using the commercial software Orca Flex. Hydrodynamics coefficients of the vessel are calculated by using a 3D diffraction/radiation panel program. First- and second-order wave forces are included in the calculations. Morison equation is used to compute the drag force on line elements representing the net. Drag coefficients are determined at every time step in the simulation considering the relative normal velocity between the structural elements and the fluid flow. The dynamic response of the coupled system is analyzed for various environments and net materials. The results of the study show the effects of solidity ratio of the net and vertical positions of the cage on the overall dynamic response of the system, confirming the viability of this type of configuration for future development of offshore aquaculture in deep waters.展开更多
Based on ANSYS software, a finite element model is built for the fatigue break of a vibration feeder influenced by an exciting force alternate load. We first study the harmonic response of the feeder and discovers the...Based on ANSYS software, a finite element model is built for the fatigue break of a vibration feeder influenced by an exciting force alternate load. We first study the harmonic response of the feeder and discovers the weak links which is an angle steel junction of side plate, feed inlet and the junction panel between the no-feed side plate and the bottom plate. Then, we carry out structural optimization. A streamlined method for optimum design of a vibration feeder is presented.展开更多
The upper vertical stability （VS） feeder is a part connected to the upper VS coil by a welding joint. The function of the feeder is to transfer current and coolant water to the VS coil. A giant electron^agnetic forc...The upper vertical stability （VS） feeder is a part connected to the upper VS coil by a welding joint. The function of the feeder is to transfer current and coolant water to the VS coil. A giant electron^agnetic force will be generated during normal operation by the current flowing in the VS coils, interacting with the external background field. The Lorentz force will induce Tresca stress in the feeder. The amplitudes of the magnetic field and Lorentz force along the conductor running direction have been calculated based on Maxwell＇s equations. To extract the Tresca stress in the feeder, a finite element model was created using the software ANSYS and an electromagnetic load was applied on the model. According to the analytical design, the stresses were classified and evaluated based on ASME. In order to reduce the Tresca stress, some optimization works have been done and the Tresca stress has had a significant reduction in the optimized model. This analytical work figured out the stress distribution in the feeder and checked the feasibility of the prototype design model. The ANSYS analysis results will provide a guidance for later improvement and fabrication.展开更多
An electromagnetic （EM） analytic model for the PF feeder, applied to ITER and needed to convey the cryogenic supply and electrical power to the PF magnets, was built up. The magnetic flux density and the EM force un...An electromagnetic （EM） analytic model for the PF feeder, applied to ITER and needed to convey the cryogenic supply and electrical power to the PF magnets, was built up. The magnetic flux density and the EM force under the worst conditions with the maximum working current in each coil were then calculated. Based on the EM analysis and theoretical calculation, the relationship between the busbar stress and the distance of neighbouring busbar supports was obtained, which provides an approach to optimize the design of the busbar supports. In order to check the feasibility of the PF feeder structure, a finite element model was built up and the ANSYS code was applied to analyze the stress and displacement. The numerical results show that the stress of the PF feeder is within the allowable limits and the structure is feasible.展开更多
The International Thermonuclear Experimental Reactor （ITER） feeder procurement is now well underway. The feeder design has been improved by the feeder teams at the ITER Organization （IO） and the Institute of Plasm...The International Thermonuclear Experimental Reactor （ITER） feeder procurement is now well underway. The feeder design has been improved by the feeder teams at the ITER Organization （IO） and the Institute of Plasma Physics, Chinese Academy of Sciences （ASIPP） in the last 2 years along with analyses and qualification activities. The feeder design is being progressively finalized. In addition, the preparation of qualification and manufacturing are well scheduled at ASIPP. This paper mainly presents the design, the overview of manufacturing and the status of integration on the ITER magnet feeders.展开更多
In Tokamaks,the toroidal field （TF） coil feeder is an important component that is used to supply the cryogens and electrical power for the TF coils.As a part of the TF feeder,the cryostat-feed through （CFT） is sub...In Tokamaks,the toroidal field （TF） coil feeder is an important component that is used to supply the cryogens and electrical power for the TF coils.As a part of the TF feeder,the cryostat-feed through （CFT） is subject to low temperatures of 9 and 80 K inside and room temperature of 300 K outside.Based on the features of the International Thermonuclear Experimental Reactor TF feeder,the thermal performance of the CFT under the nominal conditions is studied.Taking into account the conductive,convective and radiation heat transfer,the finite element model of the CFT is built.Transient thermal analysis is performed to determine the temperatures of the CFT on the 9th day of cooldown.The model is assessed by comparing the cooling curves of the CFT after 9 days.If the simulation and experimental results are the same,the finite element model can be considered as calibrated.The model predicts that the cooling time will be approximately 26 days and the temperature distribution and heat load of the main components are obtained when the CFT reaches thermal equilibrium.This study provides a valid quantitative characterization of the CFT design.展开更多
This paper presents the evolution of the design of cold mass support for the ITER magnet feeder system. The glass fibers in the cylinder and the flanges of the normal G10 support are discontinuous in the preliminary d...This paper presents the evolution of the design of cold mass support for the ITER magnet feeder system. The glass fibers in the cylinder and the flanges of the normal G10 support are discontinuous in the preliminary design. The heat load of this support from the analysis is only 4.86 W. However, the mechanical test of the prototype showed that it can only endure 9 kN lateral force, which is significantly less than the required 20 kN. So, the configuration of the glass fibers in the cylinders and flanges of this G10 support are modified by changing it to a continuous and knitted type to reinforce the support, and then a new improved prototype is manufactured and tested. It could endure 15＇kN lateral forces this time, but still not meet the required 20 kN. Finally, the SS316LN material is chosen for the cold mass supports. The analysis results show that it is safe under 20 kN lateral forces with the heat load increased to 14.8 W. Considering the practical application, the requirements of strength is of primary importance. So, this SS316LN cold mass support is acceptable for the ITER magnet feeder system. On the other hand, the design idea of using continuous and knitted glass fibers to reinforce the strength of a G10 support is a good reference for the case with a lower heat load and not too high Lorentz force.展开更多
In the International Thermonuclear Experimental Reactor（ITER） project,the feeders are one of the most important and critical systems.To convey the power supply and the coolant for the central solenoid（CS） magnet,6...In the International Thermonuclear Experimental Reactor（ITER） project,the feeders are one of the most important and critical systems.To convey the power supply and the coolant for the central solenoid（CS） magnet,6 sets of CS feeders are employed,which consist mainly of an in-cryostat feeder（ICF）,a cryostat feed-through（CFT）,an S-bend box（SBB）,and a coil terminal box（CTB）.To compensate the displacements of the internal components of the CS feeders during operation,sliding cold mass supports consisting of a sled plate,a cylindrical support,a thermal shield,and an external ring are developed.To check the strength of the developed cold mass supports of the CS3U feeder,electromagnetic analysis of the two superconducting busbars is performed by using the CATIA V5 and ANSYS codes based on parametric technology.Furthermore, the thermal-structural coupling analysis is performed based on the obtained results,except for the stress concentration,and the max.stress intensity is lower than the allowable stress of the selected material.It is found that the conceptual design of the cold mass support can satisfy the required functions under the worst case of normal working conditions.All these performed activities will provide a firm technical basis for the engineering design and development of cold mass supports.展开更多
JSC "Krastsvetmet" has launched the production of glass melting units(GU) and glass feeders(GF),with the number of bushings being from 200 to 4000,made from platinum-rhodium alloys doped with oxide forming a...JSC "Krastsvetmet" has launched the production of glass melting units(GU) and glass feeders(GF),with the number of bushings being from 200 to 4000,made from platinum-rhodium alloys doped with oxide forming and reinforcing elements.The proprietary technology for dispersion-stabilized material of PtRh10DS composition having high strength and performance properties has been developed and applied.Combined products production was launched where bushings made of PtRh-20 alloy are welded to the plate of the dispersion-stabilized PtRh10DS material.The manufacture of seamless spinning assemblies has been organized.展开更多
基金supported by National Natural Science Foundation of China (No.51867013)Natural Science Foundation of Gansu Province (No.20JR5RA414)。
文摘The purpose of this study is to analyze the galloping characteristics of the catenary positive feeder in fluctuating wind areas considering dynamic-wind angle of attack and aerodynamic damping.Firstly,the flow field model of the catenary positive feeder was established,the fluctuating wind field was simulated by Davenport wind power spectrum and linear filtering method,and the wind speed at inlet in calculation domain was controlled by editing the profile file to simulate and calculate the aerodynamic characteristics of the positive feeder in the fluctuating wind area.Then,taking the positive feeder as the research object,the mathematical model of actual structure and the corresponding finite element model were established.By applying the wind load to the finite element model,the influence of aerodynamic damping caused by the self-movement of the positive feeder on the galloping response was analyzed,and the frequency domain characteristics of galloping displacement of the positive feeder considering aerodynamic damping were studied.Finally,the calculation method of aerodynamic damping by the Guidelines for Electrical Transmission Line Structural Loading(ASCE No.74)was used for the galloping response of the positive feeder and compared with the proposed method.The results show that when considering aerodynamic damping,the galloping amplitude of the positive feeder decreases significantly,and the first-order resonance effect on the vertical displacement and horizontal displacement decreases significantly.The galloping trajectories calculated by the two methods are consistent.Therefore,this study is of great significance to further clarify the ice-free galloping mechanism of the catenary positive feeder in violent wind areas.
文摘In our previous study, five homologous feeder cell lines, Monkey ear skin fibroblasts （MESFs）, clonally derived fibroblasts from the MESFs （CMESFs）, monkey oviductal fibroblasts （MOFs）, monkey follicular granulosa fibroblast-like （MFGs） cells, monkey follicular granulosa epithelium-like （MFGEs） cells, were developed for the maintenance of rhesus embryonic stem cells （rESCs）. We found that MESFs, CMESFs, MOFs and MFGs, but not MFGEs, support the growth of rhesus embryonic stem cells. Moreover, we detected some genes that are upregulated in supportive feeder cell lines by semi-quantitative PCR. In the present study, we applied the GeneChip Rhesus Macaque Genome Array of Affymetrix Corporation to study the expression profiles of these five feeder cell lines, in purpose to find out which cytokines and signaling pathways were important in maintaining the rESCs, mRNAs of eight genes, including GREM2, bFGF, KITLG, DKK3, GREM1, AREG, SERPINF1 and LTBP1, were found to be upregulated in supportive feeder cell lines, but not in MFGE. The results indicate that many signaling pathways may play redundant roles in supporting the undifferentiated growth and maintenance of pluripotency in rESCs.
基金supported by the National Institute of Health,USA (No.R21 RR025408)
文摘Induced pluripotent stem （iPS） cells can be derived from human somatic cells by cellular reprograrnming. This technology provides a potential source of non-controversial therapeutic ceils for tissue repair, drug discovery, and opportunities for studying the molecular basis of human disease. Normally, mouse embryonic fibroblasts （MEFs） are used as feeder layers in the initial derivation of iPS lines. The pur- pose of this study was to determine whether SNL fibrohlasts can be used to support the growth of human iPS cells reprogrammed from somatic cells using lentiviral expressed reprogramming factors. In our study, iPS cells expressed common pluripotency markers, dis- played human embryonic stem cells （hESCs） morphology and unmethylated promoters of NANOG and OCT4. These data demonstrate that SNL feeder cells can support the derivation and maintenance of human iPS cells.
文摘In vitro growth and maintenance of embryonic stem (ES) cell lines derived from ICM cells of various blastocysts of 129 strain mice, the sustenance of their pluripotency and normal karyotype depend on the feeder layer of mouse embryonic fibroblasts (MEF). Compared with the feeder layer of MEF cells, medium conditioned by Buffalo rat liver cells (BRL-CM) is able to maintain pluripotency and karyo-typic normality of ES cells only in short term cell propagation. Besides, ES cells grown in BRL-CM are also capable of aggregation with 8-cell embryos of Swiss strain and develop into germ line chimaeras. Modification to the method of aggregating ES cells with early embryos by making a hole in agar layer on the top of MEF feeder cells was shown to be more convenient and efficient than the conventional microdrop method.
基金Projects(51574289,61533020,51674300)supported by the National Natural Science Foundation of ChinaProject(2015CXS017)supported by Innovation-driven Plan in Central South University,China
文摘Because of the increasingly prominent problem of alumina content inhomogeneity in large or super-scale aluminum reduction cells,a transient numerical model for the alumina mixing process was developed for a400kA cell,and the relationship between the alumina content distribution and electrolyte flow field was analyzed.In the ANSYS software platform,several numerical simulation cases were presented to display the influence of the feeder configuration on the alumina mixing characteristics.The results showed that a large vortex flow of the molten electrolyte is beneficial for alumina mixing and uniform distribution in the inner areas of the vortexes.The alumina particles reach the inter-electrode zone in10?15s from the beginning of the feeding action,and the risk of early precipitation occurs in10?25s after the feeding.It was also found that a suitable grouping of feeders could reduce the content fluctuation and gradient.Therefore,a feeding on demand strategy was proposed,and the simulation results showed that although the spatial characteristics are not changed,the uniformity of the alumina content was markedly improved.
文摘International thermonuclear experimental reactor （ITER） edge localized mode （ELM） coils are used to mitigate or suppress ELMs. The location of the coils in the vacuum vessel and behind the blankets exposes them to high radiation levels and high temperatures. The feeders provide the power and cooling water for ELM coils. They are located in the chinmey ports and experience lower radiation and temperature levels. These coils and feeders work in a high magnetic field environment and are subjected to alternating electromagnetic force due to the interaction between high magnetic field and alternating current （AC） current in the coils. They are also subjected to thermal stresses due to thermal expansion. Using the ITER upper ELM coil and feeder as an example, mechanical analyses are performed to verify and optimize the updated design to enhance their structural performance. The results show that the conductor, jacket and bracket can meet the static, fatigue and crack threshold criteria. The optimization indicates that adding chamfers to the bracket can reduce the high stress of the bracket, and removing two rails can reduce the peak reaction force on the two rails arising from thermal expansion.
文摘Two common problems for a typical Power distribution system are voltage collapse & instability. Challenge is to identify the vulnerable nodes and apply the effective corrective actions. This paper presents a probabilistic fuzzy approach to assess the node status and proposes feeder reconfiguration as a method to address the same. Feeder reconfiguration is altering the topological structures of distribution feeders by changing the open/closed states of the sectionalizing and ties switches. The solution is converge using a probabilistic fuzzy modeled solution, which defines the nodal vulnerability index (VI) as a function of node voltage and node voltage stability index and predicts nodes critical to voltage collapse. The information is further used to plan best combination of feeders from each loop in distribution system to be switched out such that the resulting configuration gives the optimal performance i.e. best voltage profile and minimal kW losses. The proposed method is tested on established radial distribution system and results are presented.
文摘The performance of complementary feeders, running in parallel, can be significantly improved by installing static transfer switches （STSs） at critical locations. We develop the STS control logic, which transfers the critical load from the preferred feeder to the alternate feeder when a voltage sag or a fault occurs on the preferred feeder. A forced commutation technique is proposed and implemented to turn off the preferred feeders＇ thyristor, thus avoiding cross current to flow and minimizing the transfer time. Simulation results show that the forced commutation technique is more effective as compared to the recently proposed time delay technique for STS operation. Two different feeders, namely New Exchange, the preferred feeder, and Sector 1-10/2, the alternate feeder of Islamabad Electric Supply COmpany （IESCO）, Pakistan, have been selected for case studies. The software PSCAD/EMTDC professional package has been used for simulation.
基金Supported by the Project Plan of Science and Technology Assistance in Xinjiang Autonomous Region(No.201491171)
文摘AIM： To explore the possibility of human umbilical cord mesenchymal stem cells（h UCMSCs）, human umbilical vein endothelial cells（h UVECs）, human dental pulp stem cells（h DPSCs） and human periodontal ligament stem cells（h PDLSCs） serving as feeder cells in co-culture systems for the cultivation of limbal stem cells.METHODS： Different feeder layers were cultured in Dulbecco＇s modified Eagle＇s medium（DMEM）/F12 and were treated with mitomycin C. Rabbits limbal stem cells（LSCs） were co-cultured on h UCMSCs, h UVECs, h DPSCs, h PDLSCs and NIH-3T3, and then comparative analysis were made between each group to see their respective colony-forming efficiency（CFE） assay and immunofluorescence（IPO13,CK3/12）.RESULTS： The efficiency of the four type cells in supporting the LSCs morphology and its cellular differentiation was similar to that of NIH-3T3 fibroblasts as demonstrated by the immunostaining properties analysis, with each group exhibiting a similar strong expression pattern of IPO13, but lacking CK3 and CK12 expression in terms of immunostaining. But h UCMSCs, h DPSCs and h PDLSCs feeder layers were superior in promoting colony formation potential of cells when compared to h UVECs and feedercell-free culture.CONCLUSION： hUCMSCs, hDPSCs and hPDLSCs can be a suitable alternative to conventional mouse NIH-3T3 feeder cells, so that risk of zoonotic infection can be diminished.
基金JSPS KAKENHI under Grant Nos.20K14736 and 19K04376.
文摘This paper proposes the design concept of a dynamic charging system for electric vehicles using multiple transmitter coils connected to a common radio frequency(RF)feeder driven by a pair of two power supplies.Using a common RF feeder for multiple transmitter coils reduces the power electronic redundancy compared to a conventional system,where each transmitter coil is individually driven by one switched-mode power supply.Currently,wireless charging of electric vehicles is recommended to operate in the frequency range of 85 kHz and beyond.In this frequency range,the signal wavelength is shorter than about 3.5 km.Therefore,a charging pad longer than several hundred meters is subject to the standing wave effect.In such a case,the voltage significantly varies along the RF feeder,resulting in a variation in the received power level when the receiver moves.Specifically,the received power significantly deteriorates when the receiver is nearby a node of the voltage standing wave.In this paper,we employ a pair of two power sources which are electrically separated by an odd-integer number of the quarter wavelength to drive the RF feeder.As a result,the voltage standing wave generated by one power source is complemented by that of the other,leading to stable received power and transmission efficiency at all the receiver’s positions along with the charging pad.Simulation results at the 85 kHz frequency band verify the output power stabilization effect of the proposed design.It is worth noting that the proposed concept can also be applied to simultaneous wireless information and power transfer(SWIPT)for passive radio frequency identification(RFID)tags by raising the operation frequency to higher industrial,scientific and medical(ISM)bands,e.g.,13.56 MHz and employing similar modulation methods as in the current RFID technology.
基金supported by the National Natural Science Fund for Distinguished Young Scientists(31025024)the National Natural Sciences Foundation of China(31272348)+1 种基金National Science Fund for Fostering Talents in Basic Research(J1210002)grants from the Ministry of Science and Technology of the People’s Republic of China(2014FY210200,2014FY110100,2013FY111200)
文摘In China, 31 genera and 95 species of fungivorous Phlaeothripinae are recorded here, of which 7 species are newly recorded and illustrated. An illustrated identification key to the 94 species is also provided, together with the information of specimens examined, and distribution of each species.
基金Kampachi Farms LLC for their support to complete this work and for all the technical information provided to complete the numerical model
文摘In the present study, the dynamic response of a coupled SPM-feeder-cage system under irregular waves and shear currents is analyzed. A numerical model is developed by using the commercial software Orca Flex. Hydrodynamics coefficients of the vessel are calculated by using a 3D diffraction/radiation panel program. First- and second-order wave forces are included in the calculations. Morison equation is used to compute the drag force on line elements representing the net. Drag coefficients are determined at every time step in the simulation considering the relative normal velocity between the structural elements and the fluid flow. The dynamic response of the coupled system is analyzed for various environments and net materials. The results of the study show the effects of solidity ratio of the net and vertical positions of the cage on the overall dynamic response of the system, confirming the viability of this type of configuration for future development of offshore aquaculture in deep waters.
文摘Based on ANSYS software, a finite element model is built for the fatigue break of a vibration feeder influenced by an exciting force alternate load. We first study the harmonic response of the feeder and discovers the weak links which is an angle steel junction of side plate, feed inlet and the junction panel between the no-feed side plate and the bottom plate. Then, we carry out structural optimization. A streamlined method for optimum design of a vibration feeder is presented.
文摘The upper vertical stability （VS） feeder is a part connected to the upper VS coil by a welding joint. The function of the feeder is to transfer current and coolant water to the VS coil. A giant electron^agnetic force will be generated during normal operation by the current flowing in the VS coils, interacting with the external background field. The Lorentz force will induce Tresca stress in the feeder. The amplitudes of the magnetic field and Lorentz force along the conductor running direction have been calculated based on Maxwell＇s equations. To extract the Tresca stress in the feeder, a finite element model was created using the software ANSYS and an electromagnetic load was applied on the model. According to the analytical design, the stresses were classified and evaluated based on ASME. In order to reduce the Tresca stress, some optimization works have been done and the Tresca stress has had a significant reduction in the optimized model. This analytical work figured out the stress distribution in the feeder and checked the feasibility of the prototype design model. The ANSYS analysis results will provide a guidance for later improvement and fabrication.
文摘An electromagnetic （EM） analytic model for the PF feeder, applied to ITER and needed to convey the cryogenic supply and electrical power to the PF magnets, was built up. The magnetic flux density and the EM force under the worst conditions with the maximum working current in each coil were then calculated. Based on the EM analysis and theoretical calculation, the relationship between the busbar stress and the distance of neighbouring busbar supports was obtained, which provides an approach to optimize the design of the busbar supports. In order to check the feasibility of the PF feeder structure, a finite element model was built up and the ANSYS code was applied to analyze the stress and displacement. The numerical results show that the stress of the PF feeder is within the allowable limits and the structure is feasible.
基金supported by the National Special Support for R&D on Science and Technology for ITER(Ministry of Public Security of the People's Republic of China-MPS)(No.2008GB102000)
文摘The International Thermonuclear Experimental Reactor （ITER） feeder procurement is now well underway. The feeder design has been improved by the feeder teams at the ITER Organization （IO） and the Institute of Plasma Physics, Chinese Academy of Sciences （ASIPP） in the last 2 years along with analyses and qualification activities. The feeder design is being progressively finalized. In addition, the preparation of qualification and manufacturing are well scheduled at ASIPP. This paper mainly presents the design, the overview of manufacturing and the status of integration on the ITER magnet feeders.
基金support of the Province Postdoctoral Foundation of Jiangsu (1501164B)the Technical Innovation Nurturing Foundationof Yangzhou University(2015CXJ016)China Postdoctoral Science Foundation(2016M600447)
文摘In Tokamaks,the toroidal field （TF） coil feeder is an important component that is used to supply the cryogens and electrical power for the TF coils.As a part of the TF feeder,the cryostat-feed through （CFT） is subject to low temperatures of 9 and 80 K inside and room temperature of 300 K outside.Based on the features of the International Thermonuclear Experimental Reactor TF feeder,the thermal performance of the CFT under the nominal conditions is studied.Taking into account the conductive,convective and radiation heat transfer,the finite element model of the CFT is built.Transient thermal analysis is performed to determine the temperatures of the CFT on the 9th day of cooldown.The model is assessed by comparing the cooling curves of the CFT after 9 days.If the simulation and experimental results are the same,the finite element model can be considered as calibrated.The model predicts that the cooling time will be approximately 26 days and the temperature distribution and heat load of the main components are obtained when the CFT reaches thermal equilibrium.This study provides a valid quantitative characterization of the CFT design.
基金supported by ITER IO, the National Basic Research Program of China (973 Program, No. 2008CB717906)the National Special Support for R&D on Science and Technology for ITER (No. 2008GB102000)
文摘This paper presents the evolution of the design of cold mass support for the ITER magnet feeder system. The glass fibers in the cylinder and the flanges of the normal G10 support are discontinuous in the preliminary design. The heat load of this support from the analysis is only 4.86 W. However, the mechanical test of the prototype showed that it can only endure 9 kN lateral force, which is significantly less than the required 20 kN. So, the configuration of the glass fibers in the cylinders and flanges of this G10 support are modified by changing it to a continuous and knitted type to reinforce the support, and then a new improved prototype is manufactured and tested. It could endure 15＇kN lateral forces this time, but still not meet the required 20 kN. Finally, the SS316LN material is chosen for the cold mass supports. The analysis results show that it is safe under 20 kN lateral forces with the heat load increased to 14.8 W. Considering the practical application, the requirements of strength is of primary importance. So, this SS316LN cold mass support is acceptable for the ITER magnet feeder system. On the other hand, the design idea of using continuous and knitted glass fibers to reinforce the strength of a G10 support is a good reference for the case with a lower heat load and not too high Lorentz force.
基金support by National Basic Research Program of China(973 Program)(No.2008CB717900)the Special Fund of ITER Project of China(No.2008GB102000)+2 种基金the Special Fund of Talent Development of Anhui Province of China(No.2009Z056)the Research Fund for the Doctoral Program of Anhui University of Architecture(No.K02425)the Fund of Anhui Educational Committee of China (No.KJ2013A072)
文摘In the International Thermonuclear Experimental Reactor（ITER） project,the feeders are one of the most important and critical systems.To convey the power supply and the coolant for the central solenoid（CS） magnet,6 sets of CS feeders are employed,which consist mainly of an in-cryostat feeder（ICF）,a cryostat feed-through（CFT）,an S-bend box（SBB）,and a coil terminal box（CTB）.To compensate the displacements of the internal components of the CS feeders during operation,sliding cold mass supports consisting of a sled plate,a cylindrical support,a thermal shield,and an external ring are developed.To check the strength of the developed cold mass supports of the CS3U feeder,electromagnetic analysis of the two superconducting busbars is performed by using the CATIA V5 and ANSYS codes based on parametric technology.Furthermore, the thermal-structural coupling analysis is performed based on the obtained results,except for the stress concentration,and the max.stress intensity is lower than the allowable stress of the selected material.It is found that the conceptual design of the cold mass support can satisfy the required functions under the worst case of normal working conditions.All these performed activities will provide a firm technical basis for the engineering design and development of cold mass supports.
文摘JSC "Krastsvetmet" has launched the production of glass melting units(GU) and glass feeders(GF),with the number of bushings being from 200 to 4000,made from platinum-rhodium alloys doped with oxide forming and reinforcing elements.The proprietary technology for dispersion-stabilized material of PtRh10DS composition having high strength and performance properties has been developed and applied.Combined products production was launched where bushings made of PtRh-20 alloy are welded to the plate of the dispersion-stabilized PtRh10DS material.The manufacture of seamless spinning assemblies has been organized.
