138,830 research outputs found
Fermented beverages with health-promoting potential: Past and future perspectives
peer-reviewedFermentation is an ancient form of food preservation, which also improves the nutritional content of foods. In many regions of the world, fermented beverages have become known for their health-promoting attributes. In addition to harnessing traditional beverages for commercial use, there have recently been innovative efforts to develop non-dairy probiotic fermented beverages from a variety of substrates, including soy milk, whey, cereals and vegetable and fruit juices. On the basis of recent developments, it is anticipated that fermented beverages will continue to be a significant component within the functional food market
Enhanced Septahedral Ordering in Cold Lennard-Jones Fluids
We report molecular dynamics calculations on two-component, cold (1.2 > T >
0.56 in natural units), three-dimensional Lennard-Jones fluids. Our system was
small (7813 A, 7812 B particles), dense (N/V = 1.30), and distinctly finite (L
\times L \times L cube, periodic boundary conditions, with L=22.96 \sigma_AA),
\sigma_AA being the range of the interaction in the Lennard-Jones
potential U_{ij} = 4 \epsilon[(\sigma_ij/r)^12 -(\sigma_ij/r)^6]. We calculated
spherical harmonic components Q_LM for the density of particles in the first
coordination shell of each particle, as well as their spherical invariants
, time-correlation functions and wavelet density decompositions. The
spherical invariants show that non-crystalline septahedral ordering
is important, especially at low temperature. While could arise from
icosahedral ordering, its behavior so closely tracks that of the nonicosahedral
that alternative origins for need to be considered. Time
correlation functions of spherical harmonic components are bimodal, with a
faster temperature-independent mode and a slow, strongly temperature-dependent
mode. Microviscosities inferred from mean-square particle displacements are
exponential in static amplitude , and track closely in temperature
dependence the orientation density slow mode lifetime. Volume wavelet
decompositions show that when T is reduced, the correlation length of
increases, especially below T=0.7, but the correlation length of is
independent of T.Comment: 14 pages, 19 figure
Industry views on water resources planning methods – prospects for change in England and Wales
This paper describes a qualitative study of practitioner perspectives on regulated water resources planning practice in England and Wales. The study focuses on strengths and weaknesses of existing practice and the case for change towards a risk-based approach informed by stochastic modelling assessments. In-depth, structured interviews were conducted to capture the views of planners, regulators and consultants closely involved in the planning process. We found broad agreement that the existing water availability assessment methods are fallible; they lack transparency, are often highly subjective and may fail to adequately expose problems of resilience. While most practitioners believe these issues warrant a more detailed examination of risk in the planning process, few believe there is a strong case for a fundamental shift towards risk-based planning informed by stochastic modelling assessments. The study identifies perceived business risks associated with change and exposes widespread scepticism of stochastic methods
Plasma contactor research, 1990
Emissive and Langmuir probes were used to measure plasma potential profiles, plasma densities, electron energy distributions, and plasma noise levels near a hollow cathode-based plasma contactor emitting electrons. The effects of electron emission current (100 to 1500 mA) and contactor flowrate (2 to 10 sccm (Xenon)) on these data are examined. Retarding potential analyzer (RPA) measurements showing that high energy ions generally stream from a contactor along with the electrons being emitted are also presented, and a mechanism by which this occurs is postulated. This mechanism, which involves a high rate of ionization induced between electrons and atoms flowing together from the hollow cathode orifice, results in a region of high positive space charge and high positive potential. Langmuir and RPA probe data suggests that both electrons and ions expand spherically from this potential hill region. In addition to experimental observations, a simple one-dimensional model which describes the electron emission process and predicts the phenomena just mentioned is presented and is shown to agree qualitatively with these observations. Experimental results of the first stage of bilateral cooperation with the Italian Institute of Interplanetary Space Physics (IFSI CNR) are presented. Sharp, well-defined double layers were observed downstream of a contactor collecting electrons from an ambient plasma created in the IFSI Facility. The voltage drop across these double layers was observed to increase with the current drawn from the ambient plasma. This observation, which was not as clear in previous IFSI tests conducted at higher neutral pressures, is in agreement with previous experimental observations made at both Colorado State University and NASA Lewis Research Center. Greater double layer voltage drops, multiple double layers, and higher noise levels in the region near the double layers were also observed when a magnetic field was imposed and oriented perpendicular to the line joining the contactor and simulator
Space plasma contractor research, 1988
Results of experiments conducted on hollow cathode-based plasma contractors are reported. Specific tests in which attempts were made to vary plasma conditions in the simulated ionospheric plasma are described. Experimental results showing the effects of contractor flowrate and ion collecting surface size on contactor performance and contactor plasma plume geometry are presented. In addition to this work, one-dimensional solutions to spherical and cylindircal space-charge limited double-sheath problems are developed. A technique is proposed that can be used to apply these solutions to the problem of current flow through elongated double-sheaths that separate two cold plasmas. Two conference papers which describe the essential features of the plasma contacting process and present data that should facilitate calibration of comprehensive numerical models of the plasma contacting process are also included
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