Emissions composition

Manor, A. and Clough, R.B. (1992), In-situ determination of fiber strength and segment length in composites by means of acoustic emission. Composites Sci. Technol. 45, 73-81. 

Black, F., S. Tejada, and M. Gurevich, Alternative Fuel Motor Vehicle Tailpipe, and Evaporative Emissions Composition and Ozone Potential, J. Air Waste Manage. Assoc., 48, 578-591 (1998). 

A number of different methods and models exists to apportion particle contributions to a specific source or source group. Unfortunately there is not a one perfect method to be employed. Different approaches are currently used depending on the type of data available and the preferences of the researchers. The various approaches vary with respect to the computational effort and to the degree of knowledge needed on the source-related emission rates and emission composition. Also, the outcomes vary between the different approaches. Nevertheless some comparison studies showed that major sources are identified by most methods and agree in their trends. Reviews can be found in, e.g. [1,2]. 

In this study we have employed the simultaneous collection of atmospheric particles and gases followed by multielement analysis as an approach for the determination of source-receptor relationships. A number of particulate tracer elements have previously been linked to sources (e.g., V to identify oil-fired power plant emissions, Na for marine aerosols, and Pb for motor vehicle contribution). Receptor methods commonly used to assess the interregional impact of such emissions include chemical mass balances (CMBs) and factor analysis (FA), the latter often including wind trajectories. With CMBs, source-strengths are determined (1) from the relative concentrations of marker elements measured at emission sources. When enough sample analyses are available, correlation calculations from FA and knowledge of source-emission compositions may identify groups of species from a common source type and identify potential marker elements. The source composition patterns are not necessary as the elemental concentrations in each sample are normalized to the mean value of the element. Recently a hybrid receptor model was proposed by Lewis and Stevens (2) in which the dispersion, deposition, and conversion characteristics of sulfur species in power-plant emissions... 

The same library was used by the authors to identify a novel, blue-white emission composite identified as Sr2Ce04 (39, 40). Another prominent group identified mag-netoresistant materials (41) and novel capacitors (42) from smaller discrete materials libraries, while joint efforts by a multi-lab group (43) proved the applicability of combinatorial technologies to the development of molecular plastic solar cells. Further examples will be described in the next section with greater focus on screening procedures. 

As the steric hindrance around the OH group decreases, solute-solvent complexation increases, resulting in the bathochromic shift of Xmax and an increase in p-emission intensity. The general solvent effect on the Xmax and the emission composition of 2 (Figure 2) suggests that the complexation process is very general and complexation becomes very pronounced in solvents of TT > 0.65. Accordingly, a-band is the Franck-Condon emission of the excited state of the solute and P-band is the Franck-Condon emission of the excited state of the solute-solvent complex. 

In the first part of this chapter a number of receptor modeling approaches will be discussed. These models are used for apportionment of the contributions of each source, identification of sources and their emission composition, and for determination of the spatial distribution of emission fluxes from a group of sources. In the second part, we will develop the tools needed to analyze the statistical character of air quality data. 

Wastney (1994) did a comprehensive literature review on gaseous emissions from drying of wood and barks with the aim of characterizing the emission composition, formation, effect on the environment, and control technologies. Later reviews by Brammer and Bridgwater (1999), and Spets and Ahtila (2004) confirmed the earlier findings by Wastney (1994). 

Park, J.-M., Kim, D.-S. and Kim, S.-R. (2003) Interfadal properties and microfailure degradation mechanisms of bioabsorbable fibers/poly-L-lactide composites using micromechanical test and nondestructive acoustic emission. Composites Science and Technology, 63, 403 19. 

A system for the production of low smoke emission composites by hand-lay, spray/projection and RTM techniques. Offers low viscosity and excellent wet-out. Catalyst PX-13 is a solution of organic and inorganic acids. 

E. Maillet, N. Godin, M. R Mili, P. Reynaud, G. Fantozzi, J. Lamon, Damage monitoring and identification in SiC/SiC minicomposites using combined acousto-uitrasonics and acoustic emission. Composites Part A, 57 8-15,2014. 

There always is a relation between fuel composition and that of hydrocarbon emissions to the atmosphere, whether it concerns hydrocarbon emissions from evaporative losses from the fuel system, or from exhaust gases. This is the reason that environmental protection regulations include monitoring the composition of motor and heating fuels. We will describe here the regulations already in existence and the work currently underway in this area with its possible effects on refining. 

Relations between Gasoline Composition and Pollutant Emissions... 

These are carbon monoxide, CO, unburned hydrocarbons (HC), and the nitrogen oxides, NO. In the U.S.A., a program called Auto/Oil (Burns et al., 1992), conducted by automotive manufacturers and petroleum companies, examined the effect of overall parameters of fuel composition on evaporative emissions and in the exhaust gases. The variables examined were the aromatics content between 20 and 45%, the olefins content between 5 and 20%, the MTBE content between 0 and 15% and finally the distillation end point between 138 and 182°C (more exactly, the 95% distilled point). 

Influence of the chemical composition of the fuel on pollutant emissions from vehicles in the US (auto/oil program). 

Acoustic Emission to Model the Fatigue Behaviour of Quasi-Isotropic Carbon-Epoxy Laminate Composites. 

Estimation of Quality of Composit Materials by Acoustic Emission Method. 

Lately, polymeric composite materials have found a wide recognition thanks to their unique qualities /1,2/. But use of the materials for construction, is limited, because lack of reliable diagnostic facilities. The non-destructive control method (NC), based on the acoustic emission phenomenon (AE), might offer a prospective solution to the situation. 

The present work was done with the aim to evaluate the efficiency of the acoustic emission method as a diagnostic tool for analysing a carbon plastic composite and its adhesive joints. The samples of the carbon plastic type UKN-5000 were used in the test. Non-defected samples and samples with artificial defects were tested. 

With the exception of the scanning probe microscopies, most surface analysis teclmiques involve scattering of one type or another, as illustrated in figure A1.7.11. A particle is incident onto a surface, and its interaction with the surface either causes a change to the particles energy and/or trajectory, or the interaction induces the emission of a secondary particle(s). The particles that interact with the surface can be electrons, ions, photons or even heat. An analysis of the mass, energy and/or trajectory of the emitted particles, or the dependence of the emitted particle yield on a property of the incident particles, is used to infer infomiation about the surface. Although these probes are indirect, they do provide reliable infomiation about the surface composition and structure. 

SIMS Secondary Ion mass spectroscopy A beam of low-energy Ions Impinges on a surface, penetrates the sample and loses energy In a series of Inelastic collisions with the target atoms leading to emission of secondary Ions. Surface composition, reaction mechanism, depth profiles... 

Sensitivity Sensitivity in flame atomic emission is strongly influenced by the temperature of the excitation source and the composition of the sample matrix. Normally, sensitivity is optimized by aspirating a standard solution and adjusting the flame s composition and the height from which emission is monitored until the emission intensity is maximized. Chemical interferences, when present, decrease the sensitivity of the analysis. With plasma emission, sensitivity is less influenced by the sample matrix. In some cases, for example, a plasma calibration curve prepared using standards in a matrix of distilled water can be used for samples with more complex matrices. 

Emission spectroscopy is a very useful analytical technique in determining the elemental composition of a sample. The emission may be produced in an electrical arc or spark but, since the mid-1960s, an inductively coupled plasma has increasingly been used. 

---