G.C. Pallis

Combined chemical and optical methods for monitoring the early decay stages of surrogate human models.

As the body decays shortly after death, a variety of gases and volatile organic compounds (VOCs) constantly emanate. Ethical and practical reasons limit the use of human corpses in controlled, time-dependent, intervening experiments for monitoring the chemistry of body decay. Therefore the utilization of pig carcasses serves as a potential surrogate to human models. The aim of this work was to study buried body decay in conditions of entrapment in collapsed buildings. Six domestic pigs were used to study carcass decay. They were enclosed in plastic body bags after being partially buried with rubbles, resembling entrapment in collapsed buildings. Three experimental cycles were performed, employing two pig carcasses in each cycle; VOCs and inorganic gases were measured daily, along with daily visible and thermal images. VOCs were collected in standard sorbent tubes and subsequently analyzed using a Thermal Desorption/Gas Chromatograph/high sensitivity bench-top Time-of-Flight Mass Spectrometer (TD/GC/TOF-MS). A comprehensive, stage by stage, detailed information on the decay process is being presented based on the experimental macroscopic observations, justifying thus the use of pig carcasses as surrogate material. A variety of VOCs were identified including almost all chemical classes: sulfur, nitrogen, oxygen compounds (aldehydes, alcohols, ketones, acids and esters), hydrocarbons, fluorides and chlorides. Carcasses obtained from a pig farm resulted in more sulfur and nitrogen cadaveric volatiles. Carbon dioxide was by far the most abundant inorganic gas identified along with carbon monoxide, hydrogen sulfide and sulfur dioxide. Visual monitoring was based on video captured images allowing for macroscopic observations, while thermal camera monitoring which is mostly temperature dependent, resulted in highlighting the local micro-changes on the carcasses, as a result of the intense microbial activity. The combination of chemical and optical methods proved very useful and informative, uncovering hidden aspects of the early stages of decay and also guiding in the development of combined chemical and imaging methods for the detection of dead bodies.

Factors that affect rescue time in urban search and rescue (USAR) operations

Recent structural collapses were studied in order to identify gaps in technology and to propose priorities in enhancing urban search and rescue (USAR) tools. The timelines of the events were examined with the scope of extracting critical factors that affect rescue time and can be used to define priorities in tools and technologies development, so that efficient and fast location, recovery and treatment of victims can be achieved. In this context, seven factors were identified: (1) best practices and lessons learned, (2) rescue technology, (3) community involvement, (4) information systems, (5) technology integration, (6) crisis management and (7) available budget. Each of these factors is reviewed, analyzed and discussed with the scope of providing future developments in tools and technology for USAR operations.

A scale-up field experiment for the monitoring of a burning process using chemical, audio, and video sensors

Fires are becoming more violent and frequent resulting in major economic losses and long-lasting effects on communities and ecosystems; thus, efficient fire monitoring is becoming a necessity. A novel triple multi-sensor approach was developed for monitoring and studying the burning of dry forest fuel in an open field scheduled experiment; chemical, optical, and acoustical sensors were combined to record the fire spread. The results of this integrated field campaign for real-time monitoring of the fire event are presented and discussed. Chemical analysis, despite its limitations, corresponded to the burning process with a minor time delay. Nevertheless, the evolution profile of CO2, CO, NO, and O2 were detected and monitored. The chemical monitoring of smoke components enabled the observing of the different fire phases (flaming, smoldering) based on the emissions identified in each phase. The analysis of fire acoustical signals presented accurate and timely response to the fire event. In the same content, the use of a thermographic camera, for monitoring the biomass burning, was also considerable (both profiles of the intensities of average gray and red component greater than 230) and presented similar promising potentials to audio results. Further work is needed towards integrating sensors signals for automation purposes leading to potential applications in real situations.

A preliminary study of a novel mass spectrometry based system for monitoring gases and VOCs evolved during composting of green kitchen waste

A combined system that consists of a pulsed sampling system, a capillary column as a transfer line and a mass spectrometer is used for online monitoring of complicated mixtures of gases and VOCs produced in a bioreactor. The combined system had long term stability and robust operation together with significant separation capability when the transfer line was a coated capillary column. It appeared that the optimum separation was achieved at temperatures as low as 50 °C. The system was capable of detecting reactor events and system malfunctions and of providing analytical information regarding evolved gases and VOCs. Contour plots were used for summarizing voluminous data originating from continuous (24 × 7) online monitoring of the bioreactor.