To obtain such positron microbeam, it is necessary to use objective lenses, which are commonly used in the electron microscopy. We also attempted to form the positron microbeam using a positron beam for the positron diffraction experiment and a SEM optics [6]; [7] ; [8].
Publicly Traded Companies that Benefited from Forced or Slave Labor, 1929-1945 CalPERS
At the same time, most of the former slaves had labor but no money and no land - they rejected the kind of gang labor that typified slavery. A solution was the sharecropping system focused on cotton, which was the only crop that could generate cash for the croppers, landowners, merchants and the tax collector.