Analysis of correction methods for ships' measured speed during sea trials

For all new ships sea trials should be carried out as a part of the delivery from the yard to the ship owner. An important part of the delivery sea trial is to determine the speed capability of the ship in the contractual condition, which is traditionally deep, calm water and no wind, at some specified loading condition. However, it is seldom possible to perform this particular test under such conditions, and when the test is done in other conditions, the result is corrected back to the contractual condition. The correction can be of a significant magnitude. The correction procedure can be influenced by different parameters such as wind resistance, shallow water effect, sea currents and added resistance due to diffraction. There are different experimental methods for correction of measured speed. Since the latter parameter is the most important between others, in this article added resistance due to diffraction has been calculated for three ships using existing methods and comparisoned with the speed correction result of shipbuilder company (Hyundai Heavy Industries). The results show considerable deviation between HHI sea trial speed correction method and other methods. So HHI added resistance calculation method needs to be revised

Design, simulation and construction of a position sensitive X-ray gas detector

In this paper a one dimentional position-sensitive X-ray gas detector has been designed, simulated and constructed based on Multi Wire Proportional Chamber (MWPC) with delay line position readout. These kinds of detectors are useful in soft X-ray imaging and are capable of being extended to two dimensions position readout easily. The position resolution of this detector is estimated to be 230µm &nbsp

Iranian Light Source Facility, A third generation light source laboratory

The Iranian Light Source Facility (ILSF) project is the first large scale accelerator facility which is currently under planning in Iran. On the basis of the present design, circumference of the 3 GeV storage ring is 528 m. Beam current and natural beam emittance are 400 mA and 0.477 nm.rad, respectively. Some prototype accelerator components such as high power solid state radio frequency amplifiers, low level RF system, thermionic RF gun, H-type dipole and quadruple magnets, magnetic measurement laboratory and highly stable magnet power supplies have been constructed at ILSF R&D laborator