Design and development of a CCD based optical tomography measuring system for particle sizing identification

This research investigates the use of charge coupled device (abbreviated as CCD) linear image sensors in an optical tomographic instrumentation system used for sizing particles. Four CCD linear image sensors are configured around an octagonal shaped flow pipe for a four projections system. The measurement system is explained and uses four CCD linear image sensors consisting of 2048 pixels with a pixel size of 14µm by 14µm. Hence, a high-resolution system is produced. The designed instrumentation system is calibrated using known test pieces. Spherical shaped and irregular shaped particles are tested on the designed system to complete analysis of the overall performance of the system

Image Reconstruction of a Charge Coupled Device Based Optical Tomographic Instrumentation System for Particle Sizing

This research investigates the use of charge coupled device (abbreviated as CCD) linear image sensors in an optical tomographic instrumentation system used for sizing particles. The measurement system, consisting of four CCD linear image sensors are configured around an octagonal shaped flow pipe for a four projections system is explained. The four linear image sensors provide 2,048 pixel imaging with a pixel size of 14 micron × 14 micron, hence constituting a high-resolution system. Image reconstruction for a four-projection optical tomography system is also discussed, where a simple optical model is used to relate attenuation due to variations in optical density, [R], within the measurement section. Expressed in matrix form this represents the forward problem in tomography [S] [R] = [M]. In practice, measurements [M] are used to estimate the optical density distribution by solving the inverse problem [R] = [S]−1[M]. Direct inversion of the sensitivity matrix, [S], is not possible and two approximations are considered and compared—the transpose and the pseudo inverse sensitivity matrices

British business and the telephone, 1878-1911

Most research into the early telephone system has focused on telephone providers rather than users, and this article begins to address that imbalance. The telephone was initially used to improve internal communications within firms, by connecting offices with warehouses, or by enabling staff working away from the office to report back. With the expansion of exchange networks, the commercial, intermediary and brokering sectors became heavy users of the technology for routine information transfer within business districts. Business elites continued to favour face-to-face contact for strategic business negotiations, however, and delegated telephone use to their employees.Telephones, Office Practice, Business Communications, White Collar Workers, Urban Infrastructure,