Influence of the First Preparation Steps on the Properties of GaN Layers Grown on 6H-SIC by Mbe

AbstractThe Gan heteroepitaxy on 6H-SiC is affected by the bad morphology of the substrate surface. We performed a hydrogen etching at 1550°C on the 6H-SiC(0001) substrates to obtain atomically flat terraces. An improvement of the structural properties of GaN grown by MBE on such substrates after deposition of a LT-AIN buffer layer is observed. A value of less than 220 arcsec of the FWHM of the XRD rocking curve, showing a reduced screw dislocations density, is comparable with the best results reported until now for thick GaN samples. Photoluminescence showed a structured near band edge emission spectrum with evidence of the A, B and C free exciton recombinations

OCCUPATIONAL INJURIES AMONG EMERGENCY MEDICAL SERVICES PERSONNEL, SEUS 118 PROVINCE OF LECCE. OBSERVATION PERIOD FROM 2005 TO 2010 AND EVALUATION OF ORGANIZATIONAL AND ECONOMIC EFFECTS

Background: the risk of injury to Emergency Medical Services personnel (SEUS) is still being explored. Objectives: to describe the epidemiology of occupational injuries among SEUS personnel, calculate injury rates, characterize the types of occupational exposure to risks and injuries reported by SEUS workers and evaluate organizational and economic effects. Methods: this is a retrospective study of all injury records of SEUS workers in the Province of Lecce (Italy) from January 1, 2005 to December 31, 2010. There is also an evaluation of economic and organizational effects that injuries had on 118 SEUS personnel of Lecce in 2010. Results: during the period observed, 92 files were reported. Nurses were the most involved workers (46%, p = 0.019). The main cause of occupational injury was mechanical (91%, p = 0.0001), and biological (6%), and three cases were related to heated discussions. The first cause of injury was car accidents (25%). "Sprains” and “strains” were the most frequent types of injuries (37%) among Emergency medical personnel. The 92 cases resulted in 1,851 workdays lost. Nursing personnel is the category that weighs heavily on the global cost. The phenomenon of occupational injuries has made the already critical situation worse. Conclusions: the phenomenon of occupational injuries among SEUS workers is related to the peculiar environment and to specific causes such as car accidents when operating in external locations, that turn out to be hostile and the psychological impact due to intervention conditions. Investigation on this subject may help the management of health organizations to identify more detailed prevention strategies. Economic effects of the phenomenon are very important. Organizational difficulties cannot be exclusively charged to the phenomenon of occupational injuries, but the phenomenon has worsened the situation which has been critical for several years. The gravity of this phenomenon is not helping the organizational structure which is on the brink of collapse and certainly will need great determination to return to a normal situation. References • Sterud T, Ekeberg Ø, Hem E. Health status in the ambulance services: a systematic review. BMC Health Serv Res. 2006; 6:82. • Heick R, Young T, Peek-Asa C. Occupational injuries among emergency medical ervice providers in the United States. Journal of Occupational and Environmental medicine/ American College of Occup Environ Med. 2009; 51(8): 963-968