Noise and hearing loss in firefighting

Since the NIH received a request to investigate the high degree of hearing loss in a fire department in 1980, hearing loss among firefighters has become an area of increased investigation. The author identifies the sources of occupational noise in firefighting, looks at audiometric testing and recent research in firefighting noise, and presents guidelines for implementing hearing conservation programs.     

SLIGA Based underwater weapon safety and arming system

 The Naval Surface Warfare Center, Indian Head Division (NSWCIHD) is applying microelectromechanical system (MEMS) technology to underwater weapon Safety and Arming (S&A) system development. MEMS technology provides an opportunity to develop a miniaturized S&A system that is more sophisticated with improved safety and reliability at a lower cost compared to current systems. An S&A system prevents premature initiation of the weapon while reliably ensuring initiation at the appropriate time. An S&A system uses multiple sensors and devices. In comparison with other weapon S&A systems, a critical aspect of underwater weapon S&A systems is the mechanical interlock system utilizing actuators and mechanical sensors. This paper describes the design, development and fabrication of S&A SLIGA device prototypes and of a SLIGA based S&A system. NSWCIHD worked with members of the HI-MEMS Alliance during design, development and fabrication. Advancements achieved by the HI-MEMS Alliance and SLIGA S&A design issues are discussed. Received: 25 August 1997/Accepted: 10 September 1997     

LIGA micro-openings for coherence characterization of X-rays

Infinitely thin opaque screens serving for diaphragms as defined in the visible-light optics are not feasible for operation with X-ray beams due to their high penetrability. Micro-openings of predicted sidewall shape in a gold layer up to 140 μm thick which would provide low transparency, are proposed. The proposed micro-openings were made using the LIGA technique and tested successfully at photon energies of up to 25 keV. The micro-openings can be used as targets for coherence X-ray pattern or, if long interference tails are avoided by means of the advanced sidewall shape, as X-ray beam collimators.     

The effects of physician counseling technique on parent reactions to mental retardation diagnosis

Many parents of mentally retarded children express dissatisfaction with how physicians initially communicate the diagnosis. We conducted a structured interview to identify and evaluate circumstances and counseling techniques which parents felt influenced their reactions to the initial diagnostic interview. Significant physician behaviors were an attitude of concern, appreciation of the handicapped child's value to the parents as a love object, planning an uninterrupted and unhurried discussion of the findings, allowing parent contact with the child before the diagnosis was told, sharing extensive information with the parents but without absolute predictions, and making specific practical recommendations. Satisfied parents were more likely to follow the physician's recommendations. The degree of dissatisfaction did not correlate with lag time before parents enrolled in an early childhood special education program. Other obstacles exist to early intervention.     

The volatiles of off-flavoured unblanched green peas (Pisum sativum)

Volatile extracts of moderately off-flavoured frozen peas, prepared by vacuum sublimation followed by concentration of the sublimate by low temperature vacuum distillation, were examined by gas chromatography, silica gel chromatography and combined gas chromatography–mass spectrometry. The constituents identified included alcohols (29), carbonyls (31), esters (12), hydrocarbons (19), terpenes (6) and 3-alkyl-2-methoxypyrazines (3). Olfactory monitoring of the gas chromatographic column effluent indicated that most of the strong odours were associated with alkanals, alk-2-enals, alka-2,4- and 2,6-dienals, octa-3,5-dien-2-ones, 3-alkyl-2-methoxypyrazines and hexanol. However, no compound which, by itself, could account for the “hay-like” off-flavour of peas was evident. The off-flavour is considered to be complex and composed largely of the more odorous unsaturated carbonyls derived from the enzymic breakdown of the unsaturated pea lipids. The volatiles of pea shells similarly examined were found to contain many of the compounds present in peas.