The focus of this AASERT grant was the development of two novel measurement approaches for soot property characterization: laser-induced incandescence and intrusive probe sampling of soot particles from diffusion flames. Characterization of the laser-induced incandescence technique for soot particle measurements in laminar diffusion flames resulted in the development of a new quantitative measurement technique for soot volume fraction and marked the first use of this technique for quantitative measurements. In particular, the relationship between laser fluence and the temporal character of the laser-induced incandescence signal was carefully examined and documented. Based on the laminar flame work, the technique was extended to soot particle measurements in turbulent diffusion, spray and droplet flames with similar quantitative results. Concurrently, an intrusive probe sampling system to collect soot particles from laminar diffusion flames was developed. This sampling system provided collection sample sizes up to 2 grams of soot. Large soot samples were required to allow for appropriate surface area characterization which was conducted using a BET measurement approach. jg p1.

Soot is of importance for its contribution to atmospheric particles with their adverse health impacts and for its contributions to heat transfer in furnaces and combustors, to luminosity from candles, and to smoke that hinders escape from buildings during fires and that impacts global warming or cooling. The different chapters of the book adress comprehensively the different aspects from fundamental approaches to applications in technical combustion devices.

The NATO ARW in Irkutsk was an excellent occasion for the coming together of Eastern and Western scientists who are involved in tropospheric science; the workshop has greatly contributed to the scientific and social understanding among the participants from the many different countries. Many new personal contacts were made which will help to strengthen future collaborations. In particular, the Lake Baikal area and the Limnological Institute offer splendid opportunities for environmental research which, in part, is already on going. For most participants it was the first time to see the impressive nature of the Lake Baikal region. Hopefully, there will be a chance for a follow-up event in Siberia where researchers from the East and West can again meet and engage in fruitful scientific dialogue. The book contains extended abstracts of the lectures and the poster presentations presented at the NATO ARW "Global Atmospheric Change and its Impact on Regional Air Quality" Irkutsk, Lake Baikal, Russian Federation, August 21-27, 2001. The ARW was composed of 22 oral presentations by key lecturers and 6 additional shorter oral presentations from participants. In a special poster session the 36 poster contributions were presented and discussed. Unfortunately not all contributors submitted extended abstracts, however, to compensate two contributions have been added from 2 participants who were originally invited but were unable to attend.

Soot Formation in Combustion represents an up-to-date overview. The contributions trace back to the 1991 Heidelberg symposium entitled "Mechanism and Models of Soot Formation" and have all been reedited by Prof. Bockhorn in close contact with the original authors. The book gives an easy introduction to the field for newcomers, and provides detailed treatments for the specialists. The following list of contents illustrates the topics under review:

Our interest in Mulhouse for carbon black and soot began some 30 years ago when J.B. Donnet developed the concept of surface chemistry of carbon and its involvement in interactions with gas, liquid and solid phases. In the late sixties, we began to study soot formation in pyrolytic systems and later on in flames. The idea of organ1z1ng a meeting on soot formation originated some four or five years ago, through discussions among Professor J.B. Howard, Dr. A. D'Alessio and ourselves. At that time the scientific community was becoming aware of the necessity to strictly control soot formation and emission. Being involved in the study of surface properties of carbon black as well as of formation of soot, we realized that the combustion community was not always fully aware of the progress made by the physical-chemists on carbon black. Reciprocally, the carbon specialists were often ignoring the research carried out on soot in flames. One objective of this workshop was to stimulate discussions between these two scientific communities. During the preparation of the meeting, and especially during the review process by the Material Science Committee of the Scientific Affairs Division of N.A.T.O. the toxicological aspect emerged as being an important component to be addressed during the workshop. To reflect these preoccupations we invited biologists, physical chemists and engineers, all leaders in their field. The final programme is a compromise of the different aspects of the subject and was divided in five sessions.

A criterion to define soot maturity, a theoretical modeling approach to simulate it, and its effects on the surface reactivity of soot primary particles in laminar premixed and diffusion flames are presented in the first two chapters. It is shown that the core-shell internal nanostructure of soot primary particles is a function of the overall soot Hydrogen to Carbon (H/C) ratio and can be used to distinguish nascent from mature soot primary particles. The importance of considering dehydrogenation to predict the H/C ratio and maturity of soot is illustrated. It is shown that the decay of soot surface reactivity with maturity, i.e. soot aging, is a strong function of the internal nanostructure of soot primary particles. The necessity of simulating soot maturity for comparison with experimental measurements is discussed. Structural effects of biodiesel in terms of unsaturation, i.e. C-C double bond, its position, and the presence of the ester moiety on soot formation are investigated in chapters four and five. It is shown that unsaturation increases soot formation by higher production of soot chemical growth species while more centrally located double bond increases soot formation by producing more soot nucleating species. However, the ester moiety decreases soot formation by reducing the concentration of soot chemical growth species such as acetylene. Several experimental techniques for measuring flame temperature, soot volume fraction, primary particle diameter, and aggregate structure are compared to each other in the last chapter. It is shown that Time Resolved Laser Induced Incandescence is the most reliable method to measure the volume fraction and the primary particle diameter of mature soot particles. The sensitivity of thermocouple measurements to radiation correction is analyzed and it is shown that for accurate temperature measurement with a thermocouple, it is essential to use a locally measured variable emissivity to estimate radiation cooling effects.