The lifting technique is now a well recognized tool for H∞ design and analysis of sampleddata systems. However, the efficiency of the method depends on the structure of the problem. The structure of the Ho sensitivit...The lifting technique is now a well recognized tool for H∞ design and analysis of sampleddata systems. However, the efficiency of the method depends on the structure of the problem. The structure of the Ho sensitivity problem is analyzed in this paper. And the constraints on the H∞-optimization problem and on the design parameters in lifting design are also discussed. Under such constraints the resulting performance from the design is generally low. Therefore, the lifting technique can not be recommended as a synthesis tool for the sampled-data systems. An example is also given in the paper.展开更多
In the present study twenty-two vegetable samples were collected from Iraqi market. Sealed can technique using CR-39 plastic track detector strippable has been used in order to measure radium and uranium concentration...In the present study twenty-two vegetable samples were collected from Iraqi market. Sealed can technique using CR-39 plastic track detector strippable has been used in order to measure radium and uranium concentrations. Etching was done with 6.25 N NaOH and optical microscope was used with the purpose of counting of alpha particle tracks. The values of effective radium content are found to range from 0.074 Bq/ kg to 0.566 Bq/ kg with the mean value of 0.317 Bq/kg. The values of uranium concentrations are found to range from 0.081 ppm to 0.615 ppm with the mean value of 0.345 ppm. Positive correlation has been observed between radium concentration and uranium concentrations in vegetable samples. Measurements of radium and uranium concentrations in vegetables are important from the health protection point of view, so simple and reliable analytical methods must be available.展开更多
文摘The lifting technique is now a well recognized tool for H∞ design and analysis of sampleddata systems. However, the efficiency of the method depends on the structure of the problem. The structure of the Ho sensitivity problem is analyzed in this paper. And the constraints on the H∞-optimization problem and on the design parameters in lifting design are also discussed. Under such constraints the resulting performance from the design is generally low. Therefore, the lifting technique can not be recommended as a synthesis tool for the sampled-data systems. An example is also given in the paper.
文摘In the present study twenty-two vegetable samples were collected from Iraqi market. Sealed can technique using CR-39 plastic track detector strippable has been used in order to measure radium and uranium concentrations. Etching was done with 6.25 N NaOH and optical microscope was used with the purpose of counting of alpha particle tracks. The values of effective radium content are found to range from 0.074 Bq/ kg to 0.566 Bq/ kg with the mean value of 0.317 Bq/kg. The values of uranium concentrations are found to range from 0.081 ppm to 0.615 ppm with the mean value of 0.345 ppm. Positive correlation has been observed between radium concentration and uranium concentrations in vegetable samples. Measurements of radium and uranium concentrations in vegetables are important from the health protection point of view, so simple and reliable analytical methods must be available.
