Energy-environment interface

The presence in the cluster of a positively charged impurity has also been considered, analyzing, by first principles, the screening due to the Si-NCs [123,124]. A reduction of screening in Si nanostructures with respect to bulk Si has been already observed [52] and predicted [125]. This reduction is a fundamental process at the basis of the enhancement of both the electron-hole interaction and the impurity activation energies in nanosized objects, and is due to the fact that close to the surface there is a dielectric dead layer, with a finite-range reduction of the dielectric constant due to the dielectric mismatch at the nanocrystal-environment interface. 

Fenton, J. M. Electrochemistry Energy, Environment, Efficiency, and Economics, Interface, Electrochem. Soc. 1994, 3, 38-44. 

Typical plots of the variation of the surface tension with the logarithmic concentration difference of a surfactant, a saturated hydrocarbon alcohol and an inorganic salt in an aqueous solution are shown in Figure 5.4. Surfactant molecules find a lower free-energy environment at the interface of an aqueous solution than they have in the bulk solution and prefer to concentrate at the surface. The adsorption isotherm of most surfactants shows a sharp decrease initially with the increase in the solute concentration until a plateau appears, due to the formation of micelles following the critical micelle concentration (CMC), where all the solution surface is covered with surfactant molecules. Any further addition of surfactant does not decrease the surface tension of the solution because it is directly consumed in the micelle formation process (see also Section 5.7). Saturated hydrocarbon alcohols also show a decrease in surface tension with increases in their aqueous solution concentration because they do not like to stay in the bulk solution and prefer to enrich on... 

A timely and important pubhcation... This should be a required reference book for all those working at the interface of engineering and biology for meeting challenges of the 21 st century related to health, energy, environment and sustainabihty. ... 

First-principles thermodynamic calculations can be useful in this context by comparing the relative strength of chemisorption for different ions at the metal/environment interface and delineating the relevant thermodynamic conditions. First-principles thermodynamics involves the extrapolation of internal energies determined at OK via electron structure calculation to finite temperature free energies through the incorporation of vibrational, rotational, and translational enthalpic and entropic contributions as well as configurational effects. 

Typical FNICO is shown in Fig. X/3.5.2-2B. The major components are FNICO power supply, field cable, and field cable termination devices. Power supply connections to the host control system are made at its safe area terminals, and those to the field tmnk at its hazardous area terminals. It also includes the necessary functions for a reliable fieldbus with those of an energy-limited interface. This incorporates a repeater function, connections for 24 VDC supply input, and a switchable terminator [30], Field terminators take the form of a DIN rail-mounted terminal module. In an FNICO system, the requirements are simple the wiring hub and its enclosure must be certified for zone 2 or division 2 as appropriate, and be suitable for the environment. 

Lyons BP, Clarke N, Groves C. The relative importance of domain size, domain purity and domain interfaces to the performance of bulk-heterojunetion organie photovoltaics. Energy Environ Sci 2012 5(6) 7657-7663. 

Analysis of Surface Molecular Composition. Information about the molecular composition of the surface or interface may also be of interest. A variety of methods for elucidating the nature of the molecules that exist on a surface or within an interface exist. Techniques based on vibrational spectroscopy of molecules are the most common and include the electron-based method of high resolution electron energy loss spectroscopy (hreels), and the optical methods of ftir and Raman spectroscopy. These tools are tremendously powerful methods of analysis because not only does a molecule possess vibrational modes which are signatures of that molecule, but the energies of molecular vibrations are extremely sensitive to the chemical environment in which a molecule is found. Thus, these methods direcdy provide information about the chemistry of the surface or interface through the vibrations of molecules contained on the surface or within the interface. 

When the nucleus is formed on a solid substrate by heterogeneous nucleation the above equations must be modified because of the nucleus-substrate interactions. These are reflected in the balance of the interfacial energies between the substrate and the environment, usually a vacuum, and the nucleus-vacuum and the nucleus-substrate interface energies. The effect of these terms is usually to reduce the critical size of the nucleus, to an extent dependent on... 

Unlike the energy of an atom, which can be defined in terms of its local atomic environment, its chemical potential is a truly non-local quantity. In thermal equilibrium the chemical potential of each species is a constant throughout the system, whether atoms are at the interface or in the bulk. 

The mucosa of the GIT represents an interface between the external and internal environments. The expansive surface area is necessary for the efficient hydrolysis of foodstuffs and the absorption of energy and nutrients. The mucosa also influences the systemic availability of non-nutrient compounds in the diet, both beneficial and detrimental. Digestion and absorption of glucosinolates are critical determinants of health benefits (see Chapter 4) Similarly, the bioavailability and health benefits of phytoestrogens, such as genistein (see Chapters 5 and 10) are at least partly dependent on the carrier-mediated processes of absorption associated with the GIT (Oitate et al, 2001). Moreover, the metabolic activities of the mucosa can influence the systemic concentrations and forms of dietary phytochemicals, as exemplified by research with soy isoflavones (Andlauer et al., 2000). 

Interfaces between two different media provide a place for conversion of energy and materials. Heterogeneous catalysts and photocatalysts act in vapor or liquid environments. Selective conversion and transport of materials occurs at membranes of biological tissues in water. Electron transport across solid/solid interfaces determines the efficiency of dye-sensitized solar cells or organic electroluminescence devices. There is hence an increasing need to apply molecular science to buried interfaces. 

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