Anthropogenic Carbon Aerosol Induced Carbonation in Reinforced Concrete: Deterioration Effects on Mechanical Properties

The effects of corrosion on the reinforced concrete structure due to carbonation affect its operation life. The research work considers a major critical component causing global warming as it studies the links between reinforced concrete deterioration mechanisms and anthropogenic carbon aerosol (black carbon soot) emissions in the atmosphere. Experimental tests were carried out to study the effect of carbonation caused by the emission of black carbon soot on mechanical properties and durability of reinforced concrete. Mass concrete and reinforced concrete prepared with Ordinary Portland cement (OPC) in water/cement ratios ranging from 0.45 to 0.65 were used to produce concrete samples. Compressive strength tests, tensile strength test, and carbonation depth tests were carried out on concrete to determine its level of deterioration following the carbonation effect. The carbonation chamber was prepared with carbon soot of different concentrations to simulate different levels of black carbon soot in the atmosphere. Results showed that concrete compressive strength was not totally affected by carbonation, but there was reduction in the tensile strength of reinforcing steel. The carbonation depth was observed to progress deeper into the concrete with a longer duration of exposure to carbonation agents in the chamber. The result of this study will serve as a guide during concrete installations.

Three-dimensional simulation analysis of the effect of hydrous ethanol and exhaust gas recirculation on gasoline direct injection engine combustion and emissions

To analyze the influence of hydrous ethanol on the performance of the direct injection engine, the three-dimensional simulation is carried out by using CONVERGE software coupled with the combustion mechanism of hydrous ethanol gasoline and the soot model. The combustion and soot generation characteristics of a direct injection gasoline engine burning aqueous ethanol gasoline using exhaust gas recirculation (EGR) technology were investigated. It was found that the increase of the blending ratio of the hydrous ethanol can accelerate the flame propagation speed, shorten the combustion duration, and improve the combustion isovolume. The nucleation and growth of soot are jointly controlled by PAHs and the small molecular components such as C2H2. The oxygen content properties and high reactive OH of the aqueous ethanol-containing gasoline inhibit soot formation. Compared with pure gasoline, the carbon soot precursor mass was reduced by 60%, 54.5%, 73.3% and 52.4% for 20% anhydrous ethanol blended with gasoline, A1, A2, A3 and A4, respectively, and the carbon soot mass was reduced by 63.6% and the carbon soot volume density was reduced by 40%. The introduction of EGR exhaust reduces the burning rate and leads to an increase in the production of Carbon monoxide, hydrocarbon, and soot. However, the combination of EGR with aqueous ethanol gasoline can significantly improve the engine combustion environment, significantly reducing soot and PAHs concentrations. The impact of EGR also includes the ability to reduce combustion chamber temperatures and reduce NOx emissions from aqueous ethanol gasoline by 75%.

A Tunguska sized airburst destroyed Tall el-Hammam a Middle Bronze Age city in the Jordan Valley near the Dead Sea

We present evidence that in ~ 1650 BCE (~ 3600 years ago), a cosmic airburst destroyed Tall el-Hammam, a Middle-Bronze-Age city in the southern Jordan Valley northeast of the Dead Sea. The proposed airburst was larger than the 1908 explosion over Tunguska, Russia, where a ~ 50-m-wide bolide detonated with ~ 1000× more energy than the Hiroshima atomic bomb. A city-wide ~ 1.5-m-thick carbon-and-ash-rich destruction layer contains peak concentrations of shocked quartz (~ 5–10 GPa); melted pottery and mudbricks; diamond-like carbon; soot; Fe- and Si-rich spherules; CaCO3 spherules from melted plaster; and melted platinum, iridium, nickel, gold, silver, zircon, chromite, and quartz. Heating experiments indicate temperatures exceeded 2000 °C. Amid city-side devastation, the airburst demolished 12+ m of the 4-to-5-story palace complex and the massive 4-m-thick mudbrick rampart, while causing extreme disarticulation and skeletal fragmentation in nearby humans. An airburst-related influx of salt (~ 4 wt.%) produced hypersalinity, inhibited agriculture, and caused a ~ 300–600-year-long abandonment of ~ 120 regional settlements within a > 25-km radius. Tall el-Hammam may be the second oldest city/town destroyed by a cosmic airburst/impact, after Abu Hureyra, Syria, and possibly the earliest site with an oral tradition that was written down (Genesis). Tunguska-scale airbursts can devastate entire cities/regions and thus, pose a severe modern-day hazard.

Improved In Situ Burn Efficiencies: An Overview of New Techniques and Technologies Resulting in Cleaner Burns

ABSTRACT Number: 1141152 In situ burning is an efficient response method that quickly removes large quantities of oil from the marine environment eliminating the need for collection, storage, and transport. The combustion of hydrocarbons mainly yields carbon dioxide and water; however, it also creates large plumes of black carbon soot and residues of incompletely burned oils. Three research projects focusing on improving burn efficiencies show promise to make an already efficient response method even more efficient. Specifically, a technology to increase heat transfer back into the crude oil result in more complete combustion greatly reducing carbon soot is nearing completion and will soon be ready for transfer to industry for commercialization. A study reconfiguring existing booming techniques allows more oxygen into the fire resulting in decreased soot production and cleaner burns. Finally, a fundamental study into the phenomena of fire whirls demonstrates a dramatic increase in volumes of oil burned while greatly reducing emissions. Emissions and efficiencies of the studies are compared with standard pool fires.

Carbon Soot Polymer Nanocomposites (CSPNCs): Production, Surface Morphological, Glass Transition Temperature Phenomenon and Optical Properties

The present chapter covers the production and properties of carbon soot nanoparticles (CSNPCs) and their doped carbon soot polymer nanocomposites (CSPNCs). The first part of this chapter will provide a brief introduction of carbon soot, its morphology, production and synthesis methods. The second part will explain the investigation of carbon soot nanoparticles by flame deposition method and their properties. The third part will provide a short knowledge on polymer nanocomposites (PNCs) and their processing methods. The last part will illustrate the production of carbon soot polymer nanocomposites by solution casting method and their important properties. At the end, the chapter concludes with future scopes.

Laser Irradiation of Super-Nonwettable Carbon Soot Coatings–Physicochemical Implications

Accounting the increasing commercial need of rational strategies for passive icing and anti-microbial protection, the development of simple, time-efficient and scalable laboratory micropatterning techniques is highly desirable. Whilst the laser irradiation is an acknowledged technology for rapidly tuning the properties of any carbon allotropes, including soot aerosols, very barely is known about the impact of the laser beam on the physicochemical profile of the soot if it appears as a functional coating. In this pioneering research, the prolonged laser treatment of a super-nonwettable soot coating actuates morpho-chemical transformations in the material, depending on the laser power and irradiation time, without interfering its anti-wetting capability and optical transmittance. Our observations could be used as a foundation for facilitating the launch of soot coatings with customized anti-icing and anti-microbial performance.