Determination of the fire hazards of mine materials using a radiant panel.

The objective of this study was to develop a laboratory-scale method to rank the ignition and fire hazards of commonly used underground mine materials and to eliminate the need for the expensive large-scale tests that are currently being used. A radiant-panel apparatus was used to determine the materials' relevant thermal characteristics: time to ignition, critical heat flux for ignition, heat of gasification, and mass-loss rate. Three thermal parameters, TRP, TP1 and TP4, were derived from the data, then developed and subsequently used to rank the combined ignition and fire hazards of the combustible materials from low hazard to high hazard. The results compared favorably with the thermal and ignition hazards of similar materials reported in the literature and support this approach as a simpler one for quantifying these combustible hazards.

Evaluation of detection and response times of fire sensors using an atmospheric monitoring system.

Atmospheric monitoring systems (AMS) are required when using air from conveyor belt entries to ventilate working sections in U.S. underground coal mines. AMS technology has the potential to increase fire safety mine-wide, but research is needed to determine the detection and response times for fires of a variety of combustible materials. To evaluate the potential of an AMS for fire detection in other areas of a coal mine, a series of full-scale fire experiments were conducted to determine detection and response times from fires of different combustible materials that are found in U.S. underground coal mines, including high- and low-volatility coals, conveyor belts, brattice materials, different types of wood, diesel fuel, and a foam sealant. These experiments were conducted in the Safety Research Coal Mine (SRCM) of the U.S. National Institute for Occupational Safety and Health (NIOSH) located in Pittsburgh, PA, using a commercially available AMS that is typical of current technology. The results showed that through proper selection of sensors and their locations, a mine-wide AMS can provide sufficient early fire warning times and improve the health and safety of miners.

The subspecific origin of the inland breeding colonies of the cormorant Phalacrocorax carbo in Britain.

The establishment of cormorant breeding colonies inland within south-east Britain since 1981 is a matter of major conservation and pest management concern. This study was initiated to investigate the subspecific origin of two recently established breeding colonies. The analysis examined sequence variation of the control (D-loop) region of the mitochondrial genome. Samples of tissue were obtained from 334 individuals from across the species range in western Europe from both subspecies (Phalacrocorax carbo carbo and P. c. sinensis) and 84 birds from two inland breeding colonies in Britain. Single-strand conformation polymorphism (SSCP) was used to assess mitochondrial variation among samples, revealing four haplotypes. The samples from the traditional breeding colonies clustered into three distinct phylogeographic groupings: Norway-Scotland, Wales-England-Iles des Chausey and the rest of Continental Europe. These results only partly agree with the traditional subspecific taxonomic groupings and are slightly at variance with results using microsatellite DNA frequencies, and a hypothesis using results from both studies is advanced. The subspecific origin of the inland colonies was investigated using maximum likelihood and Bayesian models.

The interpretation of noisy data from archaeological field survey: Phosphate analysis.

High soil phosphate concentrations are commonly related to intense past human activity although full understanding of this relationship requires further research. At present, practical constraints in the field, the need for extensive sampling and for rapid results, leads to the archaeologist frequently using crude but portable techniques of chemical analysis. The problems associated with the collection and interpretation of archaeological soil phosphate data are discussed. The use of Bayesian change-point analysis is proposed as a suitable statistical aid to the interpretation of such data.

Submicrometer particle detector and size analyzer.

A new instrument is described for measuring concentrations of submicrometer particulates with diameters ranging from 0.005 to 1.0 microm and concentrations as low as 750 particles per cm3 at small diameters and 25 particles per cm3 at the larger diameters. Developed by the Bureau of Mines, the instrument is capable of obtaining size distributions of the sampled particulates using an electrical mobility classification which requires voltages of less than 1000 V over the entire size range. The instrument is normally operated by 115 V ac, but it contains an internal rechargeable battery pack for up to 25 h of continuous dc operation. It has been designed primarily as an incipient fire detector, but can be used as a suspended particulate monitor and size analyzer or as a laboratory instrument for studying combustion aerosols. Representative data are presented, indicating potential uses of the instrument.