The NH bands at Lambda 3360

The bands at lambda 3360 and 3370 are analyzed and their Lambda and spin splitting, as well as a widening effect, which can be observed at these bands are described. The recordings were made at a dispersion of 0.42 A/mm

Analysing Government Decision Making in the South African Biofuels Industry: A Game Theoretic Approach

The production of biofuels in many countries is largely driven by the government strategy and incentives that are in place. In South Africa the first round of the development of such a draft strategy took place in 2005 while the official stance on biofuels was finalized in December of 2007. During the policy development process various governmental departments had strategic goals and targets that they all were required to achieve. The achievement of these strategic targets and goals is also risky and the various departments that have some form of involvement in the biofuels industry need to decide on how much risk they are willing to take. This article sketches the game that the various governmental departments played as well as the risks that they were faced with when writing the Industrial Biofuels Strategy. In establishing a Nash Equilibrium and when comparing this to the current state of affairs in the industry an investigation is launched as to what has caused the governmental department to divert so strongly from this position. A variable Z is defined and included in the model in order to explain the current state of affairs. The Z variable is also analyzed further in order to bring some form of structure to the debate on the government’s stance on the issue.Biofuels, Game Theory, Government Strategy, Agricultural and Food Policy, Research Methods/ Statistical Methods,

Charge and momentum transfer in supercooled melts: Why should their relaxation times differ?

The steady state values of the viscosity and the intrinsic ionic-conductivity of quenched melts are computed, in terms of independently measurable quantities. The frequency dependence of the ac dielectric response is estimated. The discrepancy between the corresponding characteristic relaxation times is only apparent; it does not imply distinct mechanisms, but stems from the intrinsic barrier distribution for $\alpha$-relaxation in supercooled fluids and glasses. This type of intrinsic ``decoupling'' is argued not to exceed four orders in magnitude, for known glassformers. We explain the origin of the discrepancy between the stretching exponent $\beta$, as extracted from $\epsilon(\omega)$ and the dielectric modulus data. The actual width of the barrier distribution always grows with lowering the temperature. The contrary is an artifact of the large contribution of the dc-conductivity component to the modulus data. The methodology allows one to single out other contributions to the conductivity, as in ``superionic'' liquids or when charge carriers are delocalized, implying that in those systems, charge transfer does not require structural reconfiguration.Comment: submitted to J Chem Phy

Mesoscopic non-equilibrium thermodynamics approach to non-Debye dielectric relaxation

Mesoscopic non-equilibrium thermodynamics is used to formulate a model describing non-homogeneous and non-Debye dielectric relaxation. The model is presented in terms of a Fokker-Planck equation for the probability distribution of non-interacting polar molecules in contact with a heat bath and in the presence of an external time-dependent electric field. Memory effects are introduced in the Fokker-Planck description through integral relations containing memory kernels, which in turn are used to establish a connection with fractional Fokker-Planck descriptions. The model is developed in terms of the evolution equations for the first two moments of the distribution function. These equations are solved by following a perturbative method from which the expressions for the complex susceptibilities are obtained as a functions of the frequency and the wave number. Different memory kernels are considered and used to compare with experiments of dielectric relaxation in glassy systems. For the case of Cole-Cole relaxation, we infer the distribution of relaxation times and its relation with an effective distribution of dipolar moments that can be attributed to different segmental motions of the polymer chains in a melt.Comment: 33 pages, 6 figure

Modeling fast pyrolysis of waste biomass: Improving predictive capability

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Los problemas del polvo y, del desempolvado en los hornos verticales de cemento

Not availableLa eliminación de las partículas gruesas de polvo es posible por medio de cámaras de decantación, de extractores centrífugos (ciclones) o por vía húmeda: Los ciclones sólo dan buen resultado si, bajo las condiciones de operación continuada, los gases pueden mantenerse con garantía a una temperatura superior a la del punto de rocío

Nitrogen compounds and ozone in the stratosphere: comparison of MIPAS satellite data with the Chemistry Climate Model ECHAM5/MESSy1

International audienceThe chemistry climate model ECHAM5/MESSy1 (E5/M1) in a setup extending from the surface to 80 km with a vertical resolution of about 600 m near the tropopause with nudged tropospheric meteorology allows a direct comparison with satellite data of chemical species at the same time and location. Here we present results out of a transient 10 years simulation for the period of the Antarctic vortex split in September 2002, where data of MIPAS on the ENVISAT-satellite are available. For the first time this satellite instrument opens the opportunity, to evaluate all stratospheric nitrogen containing species simultaneously with a good global coverage, including the source gas N2O which allows an estimate for NOx-production in the stratosphere. We show correlations between simulated and observed species in the altitude region between 10 and 50 hpa for different latitude belts, together with the Probability Density Functions (PDFs) of model results and observations. This is supplemented by global charts on pressure levels showing the satellite data and the simulated data sampled at the same time and location. We demonstrate that the model in most cases captures the partitioning in the nitrogen family, the diurnal cycles and the spatial distribution within experimental uncertainty. There appears to be, however, a problem to reproduce the observed nighttime partitioning between N2O5 and NO2 in the middle stratosphere

Library

This history for the Library was collected to commemorate DMACC\u27s 50th anniversary celebration during the 2015-16 academic year

Diversity of coryneforms found in infections following prosthetic joint insertion and open fractures

Summary: In a 5-year period, 73 coryneform isolates from prosthetic joint and open fracture infections in 60 patients treated in a hospital specialized in orthopedic surgery were speciated. The most frequent species wereCorynebacterium amycolatum, Corynebacterium striatum, Corynebacterium diphtheriae biotypemitis, andCorynebacterium jeikeium. At least 14 isolates were deemed clinically significant as sole agents of infectio

Challenges in Kinetic Parameter Determination for Wheat Straw Pyrolysis

Wheat straw is a renewable agricultural by-product that is currently underutilized in the production of bioenergy and bioproducts due to its high ash content, as well as high transport costs due to its low volumetric energy density. The thermogravimetric analysis of this material produces derivative curves with a single broad peak, making it difficult to identify the three conventional pseudo-components (cellulose, hemicellulose, and lignin), which is resolved using the second derivative to determine inflection points. Model-fitting methods and isoconversional methods were applied to determine the degradation kinetics of wheat straw at two different particle sizes, as well as that of a reference feedstock (beech wood), and the obtained values were used to divide the degradation curves to be compared to the experimental data. Seven different pyrolysis reaction networks from the literature were given a similar treatment to determine which provides the best estimation of the actual pyrolysis process for the case of the feedstocks under study. The impact of the potassium content in the feedstock was considered by comparing the original pathway with a modification dependent on the experimental potassium content and an estimated optimum value