Papers by Author: Greg Kennedy

Abstract: Zinc sulfide is inorganic material for electroluminescent applications. This work examines the possibility of obtaining good luminescent properties of the zinc sulfide mixture by double implosion experiment at elevated temperature.

Abstract: There are few research papers of liner shaped charge (LSC). In this time simplified LSC was made from an explosive and vertically-folded copper plate. In order to confirm a performance of the simplified LSC, steel cutting experiments were conducted by changing distance from the simplified LSC to target steel. Numerical analysis was also conducted by using Ls-dyna. Penetration depth was measured after experiments. Collision velocity of copper was calculated by using Gurnney equation. Numerical simulation model was made by SPH, because large deformation was occurred during collision of copper and steel penetration process. Results from numerical analysis were good correspondence with experimental results. Details are reported on this paper.

Abstract: Electroluminescent, EL, materials are of interest in providing high brightness for display screens found in portable electronic devices, where the battery life is limited. Currently organic luminescent materials are being used, but the lifetime is low due to the degradation of the organic material under electric field over time. Some recent work with inorganic material of zinc sulfide has indicated high brightness at very long life times. This work focuses on the thermal processing of the zinc sulfide based EL material with trinitrotoluene, TNT. The zinc sulfide based phosphor and TNT are placed in a stainless steel container that can withstand high pressure. After closing, the chamber was evacuated and subsequently heated to over 300°C. The ZnS based phosphor was heated to a high temperature as the TNT decomposed. The sample was recovered after cooling and separated by optical observation of photoluminescence with a ultraviolet lamp. X-ray diffraction analysis showed that some transformation to hexagonal wurtzite phase occurred and was retained after cooling. EL and photoluminescence, PL, measurements were performed to characterize the luminescent properties of the material. Results of SEM observations of the particle sizes are discussed. The most recent data shows that blue luminescence at 450nm can be obtained by the treatment of ZnS phosphor with TNT in this high pressure containment device.