Under the prerequisite that the incidence of cancer or tumor in negative-control nude mice inoculated subcutaneously with primary feline or canine kidney cell cultures purified in vitro at passage 3 was 0 (0/22) and 0...Under the prerequisite that the incidence of cancer or tumor in negative-control nude mice inoculated subcutaneously with primary feline or canine kidney cell cultures purified in vitro at passage 3 was 0 (0/22) and 0 (0/10), respectively. The incidence of the progressively-growing malignant tumor(MT) in positive-control nude mice inoculated subcutaneously with Hela cell cultures of KB, X, or NM20/X strain was 10/ 10, 25/25 and 5/51, respectively. The results showed that the incidence of tumor in nude mice with di-and hy-perploid YB strain of MDCK cell during 17 - 23 passages, with hyper- and hypoploid KA strain of MDCK cell during 6-8 passages, with hypoploid WB strain of MDCK cell on passage 6, with hyper-and hypoploid H strain of MDCK cell during 8-24 passages was 2/24, 6/10, 5/10 and 10/15, respectively. The chromosomal analysis results showed that the ratio of difference in the rate of modal chromosome number between high(mcs + n) and lowest (mcs)passages was not more than 5 - 15% and the structure aberrations was generally 0 -3 %. These results proved that the genetic characteristics of chromosomal number of cell lines determines their tumorigenicity, but it is species-specific. MDCK line has tumorigenicity no matter what its chromosome kary-otype is, at least it has very low tumorigenicity even when its modal chromosome number is hypoploid. It is thus evident that MDCK cell of WB or H strain can be approved as substrate for the preparation of attenuated viral vaccines, but MDCK cell of YB or KA strain can not be approved as substrate for the preparation of attenuated viral vaccines.展开更多
This paper is dedicated to analytical expression of the maximum electricity-cost ratio (M-ECR) point of the proton exchange membrane (PEM) fuel cell power generation as the function of cell constants and cost constant...This paper is dedicated to analytical expression of the maximum electricity-cost ratio (M-ECR) point of the proton exchange membrane (PEM) fuel cell power generation as the function of cell constants and cost constants. That is to formulize the maximum cost performance (MCP) magnitude and the optimal final operating (OFO) location in the working zone based on the five-constant ideal cell model and the two-constant cost model. The issues are well resolved by introducing the concepts of economic voltage and cost factor and describing the movement of the M-ECR point with cost factor. According to mathematical derivations, the movement can be described in the form of MCP and OFO curves. The derivations lead to a complete set of discriminants and criteria of the M-ECR point of PEM fuel cells that theoretically cover all of cell specialties and all of cost specialties. The discriminants and criteria may act as a general tool for the operation optimization of a diversity of PEM fuel cells and the economic viability estimation of the power generation.展开更多
The energy efficiency of proton exchange membrane (PEM) fuel cells always keeps changing with load and time. Considering cell diversity and operation variety, it’s of necessity to find a simple method to estimate the...The energy efficiency of proton exchange membrane (PEM) fuel cells always keeps changing with load and time. Considering cell diversity and operation variety, it’s of necessity to find a simple method to estimate the changes. The work is done with the recently developed ideal cell model on behalf of various real cells, and results in a complete set of efficiency formulae including one for the instantaneous and three for the average. The formulae stand for a volt-ampere method which permits the average efficiency to be estimated in the form of state function of cell output like the instantaneous efficiency. With cell constants for cell specialty representation in this method, the formulae can extend to cover various real cells and make it realized to broadly overview the instantaneous and average efficiency movements with both load and time throughout cell operating ranges. The energy efficiency formulization and overviews may help make clear the correlative parameters with the efficiency, help deepen acquaintance with efficiency change and assist in cell operation optimization.展开更多
The main objective of this research work is to decrease work function of any given element or compound or material. To decrease the work function of the given material we have to decrease the bandwidth between conduct...The main objective of this research work is to decrease work function of any given element or compound or material. To decrease the work function of the given material we have to decrease the bandwidth between conduct band and valance band. Because according to definition of work function, the amount of energy that required the remove the electron from valance band of an atom and it is also called ionization energy. These all energies depend upon the band width that is greater than the band width greater energy required to remove the electron from the surface, and less than the band width and lesser amount of energy required to remove the electron from of materials. In this work we are trying to give an theoretical model or relation, how to decrease the work function of a material by applying external pressure on atoms and doping of the material that has screening or shielding effects. With the help of this model we can increase the efficiency of material used in solar cell that is cell work for all range of frequencies and by construction material bases on this we can increase the efficiency of solar cell or any type of material working solar cell principle.展开更多
The purpose of this study is to explore the effects of working fluid on conventional combined cycle integrated with pressurized solid oxide fuel cell (SOFC) and waste heat recovery organic Rankine cycle (ORC) for stat...The purpose of this study is to explore the effects of working fluid on conventional combined cycle integrated with pressurized solid oxide fuel cell (SOFC) and waste heat recovery organic Rankine cycle (ORC) for stationary utility power generation. The mathematical model of a natural gas fueled design configuration is developed in Matlab and Simulink and simulated with 14 working fluids. The effluent gases of SOFC undergo combustion in the combustion chamber and it is utilized in the gas turbine, steam turbine cycle and ORC. The model is compared with those found in literature and the parametric studies of temperature, flow rate, fuel utilization factor and exhaust gas on the system efficiency are examined. Results revealed that working fluids show a closely related behavior in efficiency at low pressure ratio and high flow fraction, fuel utilization, and temperature. R-123 was found to perform the best among 14 working fluids studied, yielding a system energy efficiency of 70% in the combined cycle integrated with SOFC and ORC.展开更多
文摘Under the prerequisite that the incidence of cancer or tumor in negative-control nude mice inoculated subcutaneously with primary feline or canine kidney cell cultures purified in vitro at passage 3 was 0 (0/22) and 0 (0/10), respectively. The incidence of the progressively-growing malignant tumor(MT) in positive-control nude mice inoculated subcutaneously with Hela cell cultures of KB, X, or NM20/X strain was 10/ 10, 25/25 and 5/51, respectively. The results showed that the incidence of tumor in nude mice with di-and hy-perploid YB strain of MDCK cell during 17 - 23 passages, with hyper- and hypoploid KA strain of MDCK cell during 6-8 passages, with hypoploid WB strain of MDCK cell on passage 6, with hyper-and hypoploid H strain of MDCK cell during 8-24 passages was 2/24, 6/10, 5/10 and 10/15, respectively. The chromosomal analysis results showed that the ratio of difference in the rate of modal chromosome number between high(mcs + n) and lowest (mcs)passages was not more than 5 - 15% and the structure aberrations was generally 0 -3 %. These results proved that the genetic characteristics of chromosomal number of cell lines determines their tumorigenicity, but it is species-specific. MDCK line has tumorigenicity no matter what its chromosome kary-otype is, at least it has very low tumorigenicity even when its modal chromosome number is hypoploid. It is thus evident that MDCK cell of WB or H strain can be approved as substrate for the preparation of attenuated viral vaccines, but MDCK cell of YB or KA strain can not be approved as substrate for the preparation of attenuated viral vaccines.
文摘This paper is dedicated to analytical expression of the maximum electricity-cost ratio (M-ECR) point of the proton exchange membrane (PEM) fuel cell power generation as the function of cell constants and cost constants. That is to formulize the maximum cost performance (MCP) magnitude and the optimal final operating (OFO) location in the working zone based on the five-constant ideal cell model and the two-constant cost model. The issues are well resolved by introducing the concepts of economic voltage and cost factor and describing the movement of the M-ECR point with cost factor. According to mathematical derivations, the movement can be described in the form of MCP and OFO curves. The derivations lead to a complete set of discriminants and criteria of the M-ECR point of PEM fuel cells that theoretically cover all of cell specialties and all of cost specialties. The discriminants and criteria may act as a general tool for the operation optimization of a diversity of PEM fuel cells and the economic viability estimation of the power generation.
文摘The energy efficiency of proton exchange membrane (PEM) fuel cells always keeps changing with load and time. Considering cell diversity and operation variety, it’s of necessity to find a simple method to estimate the changes. The work is done with the recently developed ideal cell model on behalf of various real cells, and results in a complete set of efficiency formulae including one for the instantaneous and three for the average. The formulae stand for a volt-ampere method which permits the average efficiency to be estimated in the form of state function of cell output like the instantaneous efficiency. With cell constants for cell specialty representation in this method, the formulae can extend to cover various real cells and make it realized to broadly overview the instantaneous and average efficiency movements with both load and time throughout cell operating ranges. The energy efficiency formulization and overviews may help make clear the correlative parameters with the efficiency, help deepen acquaintance with efficiency change and assist in cell operation optimization.
文摘The main objective of this research work is to decrease work function of any given element or compound or material. To decrease the work function of the given material we have to decrease the bandwidth between conduct band and valance band. Because according to definition of work function, the amount of energy that required the remove the electron from valance band of an atom and it is also called ionization energy. These all energies depend upon the band width that is greater than the band width greater energy required to remove the electron from the surface, and less than the band width and lesser amount of energy required to remove the electron from of materials. In this work we are trying to give an theoretical model or relation, how to decrease the work function of a material by applying external pressure on atoms and doping of the material that has screening or shielding effects. With the help of this model we can increase the efficiency of material used in solar cell that is cell work for all range of frequencies and by construction material bases on this we can increase the efficiency of solar cell or any type of material working solar cell principle.
文摘The purpose of this study is to explore the effects of working fluid on conventional combined cycle integrated with pressurized solid oxide fuel cell (SOFC) and waste heat recovery organic Rankine cycle (ORC) for stationary utility power generation. The mathematical model of a natural gas fueled design configuration is developed in Matlab and Simulink and simulated with 14 working fluids. The effluent gases of SOFC undergo combustion in the combustion chamber and it is utilized in the gas turbine, steam turbine cycle and ORC. The model is compared with those found in literature and the parametric studies of temperature, flow rate, fuel utilization factor and exhaust gas on the system efficiency are examined. Results revealed that working fluids show a closely related behavior in efficiency at low pressure ratio and high flow fraction, fuel utilization, and temperature. R-123 was found to perform the best among 14 working fluids studied, yielding a system energy efficiency of 70% in the combined cycle integrated with SOFC and ORC.
