THz Properties of Nematic Liquid Crystals

We systematically study the terahertz (THz) properties of a set of nematic liquid crystals. We use THz time domain spectroscopy to obtain data between 0.2 THz up to 2.5 THz. Such a broadband set of terahertz data has not yet been reported. From the measured data, we extract macroscopic data, such as the birefringence, the refractive indices and the absorption coefficients for ordinary and extraordinary polarization. The impact of different side chains and core structures on the terahertz anisotropy are discussed. This paper will serve as a data base and can be very useful for the design of new terahertz liquid crystal material.     

Influence of hydrolysed lecithin addition on protein adsorption and heat stability of a sterilised coffee cream simulant

Within an overall goal to enhance the stability of coffee cream, the influence of hydrolysed soybean lecithin addition was investigated. To avoid the seasonal variations in milk composition a model system was used containing 5% (w/w) soybean oil and 12% (w/w) skimmed milk powder with and without lecithin addition before a two-step high-pressure homogenisation. Addition of 20% (w/v) caesium chloride enabled a nearly complete recovery of the fat in the cream layer upon centrifugation of casein-stabilised emulsions. From the fat and protein content of this cream layer, it was concluded that lecithin addition did not significantly affect the protein content of the cream layer after emulsion preparation, but significantly reduced the additional milk protein adsorption at the oil/water interface upon sterilisation. The experimental data suggest that the enhanced heat stability of the lecithin-supplemented coffee cream simulant may be explained by the fact that hydrolysed lecithin largely reduces attractive protein–protein interactions during sterilisation.     

Actual versus Predicted Transboundary Impact: A Case Study of Phase 1B of the Lesotho Highlands Water Project

The Lesotho Highlands Water Project was initiated in 1986 as a result of discussions between the governments of the Kingdom of Lesotho and the Republic of South Africa (SA) that, together with feasibility studies, had commenced in the early 1950s. The project targeted the Senqu River, which originates in the Lesotho Highlands, merges with the Orange River in South Africa, and drains into the Atlantic Ocean, creating a natural border between Namibia and South Africa. Four riparian states, including Botswana, rely heavily on the Sengu's water for development. The multi-donor billion-dollar project consisted of two initial phases, 1A and 1B. No impact assessment was conducted for Phase 1A. As a result of international critique, lessons learned and the involvement of the World Bank, Phase 1B considered all possible environmental, social and economic impacts. The full-scale EIA recognized, but did not fully consider, transboundary impacts, which were only addressed through the commissioning of an In-stream Flow Requirement (IFR) study in 2000, once the project commenced.     

THz Spectroscopy of Liquid Crystals from the CB Family

Liquid crystals represent a very interesting material system but their properties in the THz range have not been extensively investigated yet. In this paper we investigate the THz properties of four liquid crystals from the CB family (5CB, 6CB, 7CB and 8CB). In addition to absolute refractive indices and absorption coefficients we present accurate birefringence measurements for different electric fields and temperatures.     

LSP suitability maps

In this paper, we propose the concept of logically aggregated geographic suitability maps (LSP-maps). The goal of LSP-maps is to provide specialized maps of the suitability degree of a selected geographic region for a specific purpose. There is a wide spectrum of purposes which include suitability for industrial development, agriculture, housing, education, recreation, etc. Our goals are to specify the main concepts of LSP-maps development and to identify some of the potential application areas. Our approach is based on soft computing with partial truth and graded logic functions within the framework of the LSP method.     

Assessing scientific collaboration through coauthorship and content sharing

Over the past decade there have been many investigations aimed at defining the role of scientists and research groups in their coauthorship networks. Starting from the assumptions of network analysis, in this work we propose an analytical definition of a collaboration potential between authors of scientific papers based on both coauthorships and content sharing. The collaboration potential can also be considered a useful tool to investigate the relationships between a single scientist and research groups, thus allowing for the identification of characteristic “types” of scientists (integrated, independent, etc.). We computed the collaboration potential for a set of authors belonging to research groups of an institute specialized in the field of Medical Genetics. The methods presented in the paper are rather general as they can be applied to compute a collaboration potential for a network of cooperating actors in every situation in which one can qualify the content of some activities and which of them are in common among the actors of the network.     

Diffraction of horizontally polarized ultrasonic plane waves on a periodically corrugated solid-liquid interface for normal incidence and Brewster angle incidence

The theory, and the use at normal incidence, of shear-vertically polarized waves (with polarization vector in the plane containing the incident wave vector and the normal on the interface) using the mode conversion method has been tackled by others. Here we develop the theory for shear-horizontally polarized incident waves (with polarization vector perpendicular to both the normal on the interface and the incoming wave vector). We take into account normal incidence as well as oblique incidence. For normal incidence, we discover the generation of Love waves. If oblique incidence is considered, we discover the existence of a Brewster angle of incidence, comparable with the Brewster angle in optics, in which a diffraction grating can be used as a polarization filter.     

Bioaugmenting bioreactors for the continuous removal of 3-chloroaniline by a slow release approach

The survival and activity of microbial degradative inoculants in bioreactors is critical to obtain successful biodegradation of non- or slowly degradable pollutants. Achieving this in industrial wastewater reactors is technically challenging. We evaluated a strategy to obtain complete and stable bioaugmentation of activated sludge, which is used to treat a 3-chloroaniline (3-CA) contaminated wastewater in a lab-scale semi-continuous activated sludge system. A 3-CA metabolizing bacterium, Comamonas testosteroni strain I2, was mixed with molten agar and encapsulated in 4 mm diameter open-ended silicone tubes of 3 cm long. The tubes containing the immobilized bacteria represented about 1% of the volume of the mixed liquor. The bioaugmentation activity of a reactor containing the immobilized cells was compared with a reactor with suspended I2gfp cells. From day 25-30 after inoculation, the reactor with only suspended cells failed to completely degrade 3-CA because of a decrease in metabolic activity. In the reactors with immobilized cells, however, 3-CA continued to be removed. A mass balance indicated that ca. 10% of the degradation activity was due to the immobilized cells. Slow release of the growing embedded cells from the agar into the activated sludge medium, resulting in a higher number of active 3-CA-degrading I2 cells, was responsible for ca. 90% of the degradation. Our results demonstrate that this simple immobilization procedure was effective to maintain a 3-CA-degrading population within the activated sludge community.     

Azo Compounds Derived from Electrochemical Reduction of Nitro Compounds for High Performance Li‐Ion Batteries

Organic compounds are desirable alternatives for sustainable lithium‐ion battery electrodes. However, the electrochemical properties of state‐of‐the‐art organic electrodes are still worse than commercial inorganic counterparts. Here, a new chemistry is reported based on the electrochemical conversion of nitro compounds to azo compounds for high performance lithium‐ion batteries. 4‐Nitrobenzoic acid lithium salt (NBALS) is selected as a model nitro compound to systemically investigate the structure, lithiation/delithiation mechanism, and electrochemical performance of nitro compounds. NBALS delivers an initial capacity of 153 mAh g^?1 at 0.5 C and retains a capacity of 131 mAh g^?1 after 100 cycles. Detailed characterizations demonstrate that during initial electrochemical lithiation, the nitro group in crystalline NBALS is irreversibly reduced into an amorphous azo compound. Subsequently, the azo compound is reversibly lithiated/delithiated in the following charge/discharge cycles with high electrochemical performance. The lithiation/delithiation mechanism of azo compounds is also validated by directly using azo compounds as electrode materials, which exhibit similar electrochemical performance to nitro compounds, while having a much higher initial Coulombic efficiency. Therefore, this work proves that nitro compounds can be electrochemically converted to azo compounds for high performance lithium‐ion batteries.