Particles elemental carbon

The relative contribution of primary and secondary carbon to urban aerosol is discussed in this paper. Some data from the ACKEX study in Los Angeles have been reexamined using new values for the carbon and lead emissions. Data on total carbon, elemental carbon and lead in fine particle samples collected in St. Louis are presented. Lead and elemental carbon have been shown to be useful tracers of primary carbonaceous aerosol. It is concluded that secondary carbon is most likely to be a significant portion of the urban carbonaceous aerosol in the summer and in the middle of the day. Secondary carbon can best be measured with short time resolution sampling (At 6h). 

Fine Aerosol Mass Balance. The temporal variations of fine particle mass, total carbon, elemental carbon, nitrogen, sulfur and for a typical summer period (August 4-10, 1979) and... 

A substance can be classified chemically in many ways. One of the simplest ways to classify a substance is as an element or a compound. An element is a pure substance that cannot be changed into a simpler substance by chemical means. Elements are the building blocks of nature all matter is composed of elements. The periodic table is a concise map that organizes chemical elements into columns (groups) and rows (periods) based on their chemical properties. Currently, there are 118 known chemical elements, with whole numbers 1 to 118. These numbers are referred to as the element s atomic number and give the number of protons in the nucleus of an atom of the element. For example, carbon s atomic number is 6 and each carbon atom has 6 protons in its nucleus. The first 92 elements occur naturally, and those above atomic number 92 are synthesized through nuclear reactions using particle accelerators. Element 118 was just confirmed in the fall of 2006, and by now, more elements may have been produced. 

FIGURE 10.2 (a) High-resolution TEM pictures of carbon-coated TiOj particles with 15 wt% carbon. The carbon layer (indicated with the arrows) can be clearly observed on top of the titania particles, (b) Elemental analysis of titanium and carbon can detect the domains of the respective elements as demonstrated here for a Ti02 powder with 52 wt% carbon. Clearly the carbon shells on top of the Ti02 particles can be observed along with separate pure carbon particles. (Courtesy of H.K. Kammler and S.E. Pratsinis.)... 

Step 7 We now earry out an overall balance on elemental carbon. Elemental carbon does not enter or leave the particle. 

In synthetic materials, the surface organization also depends on the internal structure of particles. Carbon black is good example. Figure 5.11 shows the models of carbon black primary particles. The most recent model developed by Hess, Ban and Heidenreich is commonly accepted as being characteristic of carbon black particles. The particle is composed of small elements which are interconnected to form quasi-spherical parti-... 

Thus, the formation of elementary particles and elements follows a logical order, which in turn can be used by scientists to delineate cosmic events and time tags. It is easier to form light elements by fusion of hydrogen, deuterium and helium, as oxygen and carbon are the two most abundant elements after hydrogen and helium. 

This contribution comprehensively reviews the literature reported for particulate emissions of motor vehicles operated under real-world conditions. This article will mainly focus on the results published for size segregated emissions factors of particle mass, elemental and organic carbon, crustal components and selected trace metals, since information is important for health effects studies and source reconciliation modeling efforts. 

Synonyms /Acetylene black Carbon black acetylene Channel black Charcoal Cl 77266 Furnace black Lamp black Qil-fumace black Pigment black 6 Pigment black 7 Thermal acetylene black Thermal atomic black Thermal black Vegetable carbon D nilion Finely divided particles of elemental carbon obtained by incomplete combustion of hydrocarbons (channel or impingement process)... 

Bertram AK, Martin ST, Hanna SJ, Smith ML, Bodsworth A, Chen Q, Kuwata M, Liu A, You Y, Zorn SR (2011) Predicting the relative humidities of liquid-liquid phase separation, efflorescence, and deliquescence of mixed particles of ammonium sulfate, organic material, and water using the organic-to-sulfate mass ratio of the particle and the oxygen-to-carbon elemental ratio of the organic component. Atmos Chem Phys 11 10995-11006... 

The use of larger particles in the cyclotron, for example carbon, nitrogen or oxygen ions, enabled elements of several units of atomic number beyond uranium to be synthesised. Einsteinium and fermium were obtained by this method and separated by ion-exchange. and indeed first identified by the appearance of their concentration peaks on the elution graph at the places expected for atomic numbers 99 and 100. The concentrations available when this was done were measured not in gcm but in atoms cm. The same elements became available in greater quantity when the first hydrogen bomb was exploded, when they were found in the fission products. Element 101, mendelevium, was made by a-particle bombardment of einsteinium, and nobelium (102) by fusion of curium and the carbon-13 isotope. 

When hydrogen is burned up in the nuclear furnace of a star, helium burning takes over, forming carbon, which in turn leads to oxygen, etc. Subsequent emission processes releasing a-particles, equilibrium processes, neutron absorption, proton capture, etc. lead to heavier elements. 

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