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A significant amount of attention has been given to the development of the catalyst supports that might lead to enhanced catalytic hydroprocessing properties over last 30 y. This chapter reviews the support effects of oxides (Al₂O₃, SiO₂, TiO₂, and ZrO₂), carbonaceous materials, and molecular sieves including MCM-41, SBA-15, SAPO, ZSM-5, zeolite Y, and zeolite beta.

The competitive process of creating blocks in blockchains — the technological backbone of cryptocurrencies — is computation intensive and consumes a large amount of energy. However, its environmental impact may not be significant, or at least not significant enough to undermine the application of digital currency as both a medium of exchange and a store of value. This chapter uses a unique dataset from the United States Environmental Protection Agency (EPA) to compare the carbon footprints of various industry sectors in the US with that of Bitcoin. Overall, the equivalent amount of greenhouse gas emissions from the Bitcoin network in 2020 is about one-third of the amount emitted by the entire mining sector in the US. In cross-sectional analysis, Bitcoin has a significantly larger carbon footprint than many companies and even industries after controlling for the economic value created. What is alarming is the rate of increase in Bitcoin’s energy consumption since 2017 and the possibility that its carbon footprint may eventually surpass all industries in the near future.

Carbon is one of the elements most abundant in nature. It is essential for living organisms, and as an element occurs with several morphologies. Nowadays, carbon is encountered widely in our daily lives in its various forms and compounds, such as graphite, diamond, hydrocarbons, fibers, soot, oil, complex molecules, etc. However, in the last decade, carbon science and technology has enlarged its scope following the discovery of fullerenes (carbon nanocages) and the identification of carbon nanotubes (rolled graphene sheets). These novel nanostructures possess physico-chemical properties different to those of bulk graphite and diamond. It is expected that numerous technological applications will arise using such fascinating structures. This account summarizes the most relevant achievements regarding the production, properties and applications of nanoscale carbon structures. It is believed that nanocarbons will be crucial for the development of emerging technologies in the following years.

Ultrafine particles (less than 100 nm in diameter) are encountered in ambient air and at the workplace. Normal background levels in the urban atmosphere for ultrafine particles are in the range 1−4 × 10⁴cm⁻³; however, their mass concentration is normally not greater than 2 μg m⁻³. At the workplace, ultrafine particles occur regularly in metal fumes and polymer fumes, both of which can induce acute inflammatory responses in the lung upon inhalation. Although ultrafine particles occurring at the workplace are not representative, and, therefore, are not relevant for urban atmospheric particles, their use in toxicological studies can give valuable information on principles of the toxicity of ultrafine particles. Studies in rats using ultrafine polymer fumes of polytetrafluoroethylene (PTFE) (count median diameter ca. 18 nm) showed that (i) they induced very high pulmonary toxicity and lethality in rats after 15 min of inhalation at 50 μg m⁻³; (ii) ageing of PTFE fumes resulted in agglomeration to larger particles and loss of toxicity; (iii) repeated pre-exposure for very short periods protected against the toxic and lethal effects of a subsequent 15 min exposure; (iv) rapid translocation of PTFE particles occurred to epithelial, interstitial and endothelial sites. Since one characteristic of urban ultrafine particles is their carbonaceous nature, exposure of rats to laboratory-generated ultrafine carbonaceous (elemental, and organic, carbon) particles was carried out at a concentration of ca. 100 μm⁻³ for 6 h. Modulating factors of responses were prior lowdose inhalation of endotoxin in order to mimic early respiratory tract infections, old age (22-month old rats versus 10-week old rats) and ozone co-exposure. Analysis of results showed that (i) ultrafine carbon particles can induce slight inflammatory responses; (ii) LPS priming and ozone co-exposure increase the responses to ultrafine carbon; (iii) the aged lung is at increased risk for ultrafine particle-induced oxidative stress. Other studies with ultrafine and fine TiO₂ showed that the same mass dose of ultrafine particles has a significantly greater inflammatory potential than fine particles. The increased surface area of ultrafine particles is apparently a most important determinant for their greater biological activity. In addition, the propensity of ultrafine particles to translocate may result in systemic distribution to extrapulmonary tissues.

This chapter describes how economic models are used to answer questions about policy changes, specifically in the context of a carbon fee-and-dividend system. A carbon fee-and-dividend is a price on carbon dioxide emissions that returns the revenues gained to ordinary households in the form of a monthly check. The chapter describes, in nontechnical terms, the economic models and modeling processes involved and how they are similar and different from climate models…

Wind turbines and Solar Photovoltaic (PV) electric energy generators are the lowest cost producers of electricity available in 2019, costing about half as much as a new coal plant’s electric energy (Lazard’s Levelized Cost of Energy Analysis, 2018). They have the important characteristic of delivering electricity without releasing greenhouse gases like carbon dioxide (CO₂). Yet, almost all experts and plans for the future say that wind and solar will not be dominant contributors to electricity generation for the next couple of decades. They say we must continue fossil fuels with their associated greenhouse gases because of problems with renewable generators…

In rechargeable lithium-sulfur (Li-S) batteries, the conductive carbon materials with high surface areas can greatly enhance the electrical conductivity of sulfur cathode, and metal oxides can restrain the dissolution of lithium polysulfides within the electrolyte through strong chemical bindings. The rational design of carbon-metal oxide nanocomposite cathodes has been considered as an effective solution to increase the sulfur utilization and improve cycling performance of Li-S batteries. Here, we summarize the recent progresses in the carbon-metal oxide composites for Li-S battery cathodes. Some insights are also offered on the future directions of carbon-metal oxide hybrid cathodes for high performance Li-S batteries.

The potential applications for heterogeneous catalysts (supported metallic complexes, metal–organic frameworks (MOFs) or polynuclear complexes) in C–H and C–OH activation are tantalizing. In response to the opportunity, novel strategies have been recently developed, which present a critical step toward harnessing the experimental factors, such as yield and selectivity, by enabling new techniques and hence real-world applications. This chapter provides an up-to-date survey (from the past five years) of the most promising novel routes by summarizing the progress made in the use of unconventional activation methods for performing oxidation reactions, highlighting the synergy of these technologies with heterogeneous catalysis. Focus is centered on both usual catalysts activation methods and less usual ones, such as ultrasounds, microwaves, grinding (mechanochemistry), as well as their combined use.

Nucleation is a word derived from nuclear family and refers to the concept of progenitor, the mother and the father of any family, which has been at the root of human life for many thousands of years. From it has emerged the concept of a breeding line of humans. Only in the last few centuries of civilization have physicists borrowed the word, and later biologists for Schwann's cell theory. Very recently it has passed to atomic theory, spectroscopy, radioactivity and to atomic bombs, fission and fusion. In physics any change in the free energy state of matter involves a nucleation or ordering of atoms into a new pattern as in any change to gas, liquid or solid or in the packing of atoms in carbon black, graphite, or diamond. Thus the word nucleation is not derived from atomic physics or cell biology. To be so deluded makes it difficult to understand the simple matter of pattern setting in any change of state.

In this paper, carbon particles with micro- and nano-particle size were synthesized through a hydrothermal reaction of glucose, namely C-1(123.1 nm), C-2(229.2 nm), C-3(335.1 nm), C-4(456.2 nm) and C-5(534.0 nm) with distinct sizes. We utilized five size carbon particles as individual fillers into the EHS matrix materials to prepare composite eutectic phase change materials (C/EHS PCMs) by melt blending technique. The impact of carbon particle size on the dispersion stability and thermal properties of Na₂SO₄·10H₂O–Na₂HPO₄·12H₂O (EHS) phase change materials was investigated. Scanning electron microscopy (SEM) and dynamic light scattering (DLS) analysis were done to analyze the diameters of carbon particles. The cryogenic-scanning electron microscopy (Cryo-SEM) analysis indicated that the carbon particles resulted in modification in the morphology of the EHS. The results of in situ X-ray diffraction (XRD) and Fourier-transformed infrared (FTIR) analysis showed only simple physical mixing between carbon particles and EHS. It is shown that adding 0.2 wt.% C-2 can decrease the supercooling degree of EHS to 1.5°C. The cyclic stability of C/EHS varies significantly depending on the size of carbon particles. The thermal conductivity of EHS increased by 42.1%, 39.9%, 14.4%, 19.5%, and 18.8% with the addition of C-1, C-2, C-3, C-4, and C-5, respectively, at a mass fraction of 0.2%. The results of differential scanning calorimetry reveal that the incorporation of C-1, C-2, C-3, and C-4 into EHS leads to an enhancement of latent heat. The latent heat capacity of EHS with 0.2 wt.% C-2 is 243.4 J·g⁻¹, and after undergoing 500 cycles of solid-liquid phase transition, the latent heat remained above 200 J·g⁻¹. Through the comprehensive analysis, the C-2/EHS composite phase change material holds significant potential for advancing building insulation and solar energy storage technologies.

Joint arthroplasty, specifically total knee arthroplasty (TKA) and total hip arthroplasty (THA), are two of the highest value surgical procedures. Over the last several decades, the materials utilized in these surgeries have improved and increased device longevity. However, with an increased incidence of TKA and THA surgeries in younger patients, it is crucial to make these materials more durable. The addition of nanoparticles is one technology that is being explored for this purpose. This review focuses on the addition of nanoparticles to the various parts of arthroplasty surgery comprising of the metallic, ceramic, or polyethylene components along with the bone cement used for fixation. Carbon additives proved to be the most widely studied, and could potentially reduce stress shielding, improve wear, and enhance the biocompatibility of arthroplasty implants.