Simulating climate change and its effects on the wind energy resource of Ireland

We consider the impact of climate change on the wind energy resource of Ireland using an ensemble of Regional Climate Model (RCM) simulations. The RCM dynamically downscales the coarse information provided by the Global Climate Models (GCMs) and provides high resolution information, on a subdomain covering Ireland. The RCM used in this work is the Rossby Center's RCM (RCA3). The RCA3 model is evaluated by performing simulations of the past Irish climate, driven by European Center for Medium‐Range Weather Forecasts ERA‐40 data, and by comparing the output to observations. Results confirm that the output of the RCA3 model exhibits reasonable and realistic features as documented in the historical wind data record. For the investigation of the influence of the future climate under different climate scenarios, the Max Plank Institute's GCM, European Center Hamburg Model, is used to drive the RCA3 model. Simulations are run for a control period 1961‐2000 and future period 2021‐2060. The future climate was simulated using the four Intergovernmental Panel on Climate Change emission scenarios A1B, A2, B1 and B2. The results for the downscaled simulations show a substantial overall increase in the energy content of the wind for the future winter months and a decrease during the summer months. The projected changes for summer and winter were found to be statistically significant over most of Ireland. However, the projected changes should be viewed with caution since the climate change signal is of similar magnitude to the variability of the evaluation and control simulations. Copyright © 2011 John Wiley & Sons, Ltd.     

Methode zur Bestimmung von Mutterkornalkaloiden in Lebensmitteln

Zusammenfassung Es wurde eine für die Routineanalytik geeignete Methode zur Bestimmung der Mutterkornalkaloide Ergometrin, Ergometrinin, Ergosin, Ergosinin, Ergotamin, Ergotaminin, Ergocornin, Ergocorninin, -Ergokryptin, -Ergokryptinin,-Ergokryptin,-Ergokryptinin, Ergocristin und Ergocristinin in Getreideprodukten entwickelt. Die Methode besteht aus der Extraktion des Lebensmittels, der Reinigung des Rohextraktes mit einer modifizierten Form des Extrelut-Verfahrens und der Identifizierung und quantitativen Bestimmung der Alkaloide mittels HPLC. Zur Absicherung der qualitativen Ergebnisse wurden DC und GC/MS hinzugezogen. Marktuntersuchungen zeigten Kontaminationen sowohl bei alternativen als auch bei herkömmlichen Produkten, wobei der Befall bei Roggenerzeugnissen überwiegt. Die gemessenen Werte lassen indes erkennen, daß in keinem Falle die in der Europäischen Gemeinschaft geltende Interventionsgrenze von 0,05% Mutterkorn entsprechend 1 mg/kg Gesamtalkaloide erreicht wurde.

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Method for the determination of ergot alkaloids in food

Summary A suitable method has been developed for the routine analysis of the ergot alkaloids ergometrine, ergometrinine, ergosine, ergosinine, ergotamine, ergotaminine, ergocornine, ergocorninine, -ergocryptine, -ergocryptinine,-ergocryptine,-ergocryptinine, ergocristine and ergocristinine in cereal products. The method consists of food extraction, cleaning of the crude extract by a modified form of the Extrelut method, and identification and quantitative determination of the alkaloids by high pressure liquid chromatography (HPLC). The results are confirmed by thin layer chromatography (TLC) and gaschromatography/mass spectrometry (GC/MS). Market investigations have shown contaminations in ecological as well as in conventional products, with rye products mainly being contaminated. Within the EEC, a maximum value of 0.05% ergot respectively a total alkaloid content of 1 mg/kg in cereals used for food production is prescribed. This value was not exceeded in any of the investigated samples.

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Seit November 1985 c/o Hoechst Aktiengesellschaft, Abteilung Lebensmitteltechnik, Postfach 80 03 20, D-6230 Frankfurt/M.80, Bundesrepublik Deutschland     

Preparation of cellulose filters with covalently bound dithiocarbamate, 8-hydroxyquinoline,and aminocarboxylic acid functional groups

Filter papers with covalently bound chelating groups are produced with the aim to enrich metal ions simultaneously for measurement by X-ray fluorescence spectrometry. The selectivity of the chelating groups to transition elements is of utmost importance. Some analytically important chelating groups dithiocarbamate-, 8-hydroxyquinoline-derivatives, and aminocarboxylic acid (EDTA analogue) are immobilized on cellulose filter papers. These filters are produced in a flow reactor, filled with commercially prefabricated analytical grade filter papers. They are synthesized in a three-step-reaction. First, an epoxyactivated cellulose is produced which in the second step is converted into an aminocellulose. This aminocellulose is the starting material for the dithiocarbamate-, the 8-hydroxyquinoline, and EDTA-analogue cellulose. The immobilization of 8-hydroxyquinoline or 8-hydroxyquinoline-5-sulfonic acid is accomplished through an aminomethylation. The analytically useful capacity of the various chelating filter papers is for dithiocarbamate, 8-hydroxyquinoline, 8-hydroxyquinoline-5-sulfonic acid, and EDTA-analogue derivatives 600, 700, 400, and 600 μmol/g, respectively.     

Die charakterisierung des mechanischenverhaltens von kohlenstoff- und graphitmaterialien mit hilfe der schallemissionsanalyse

Carbon and graphite materials stressed by external or internal forces release energy in the form of stress waves. These waves which characterize the behavior of the material, have been analyzed by means of acoustic emission analysis. Graphite will emit acoustic energy already under small bending and tension stresses (observed frequency range 0,1–0,3 MHz). The acoustic emission rate is higher during the first loading than during the following load cycles where emission can only be observed when the stress level exceeds the preceding one.When multiple loading is repeated after some stress-free time, acoustic emission will show up again during the first new load cycles. This (relaxation) effect is the higher the longer the load-free interval has been. It can also be achieved by heating the prestressed graphite, e.g. up to 1000°C. The approaching failure of graphite (under a constant or alternating load) can be predicted from the acoustic emission curve. Thus a critical crack growth may be stopped by diminishing the load.During heat treatment of baked material (petroleum coke base) up to 2500°C acoustic emission can be observed in the temperature range from 1400 to 1700°C. as the formation and evolution of sulphur compounds creates increased microporosity and an irreversible elongation of the carbon body. On cooling down a graphitized body very strong acoustic emission will occur in the temperature range from 2200° to 1500°C.By means of distribution analysis of the acoustic emission events with regard to counts per event, to pulse widths, and to amplitudes, one can distinguish between low and high loading phases of graphite components. By applying distribution analysis one can also determine the difference in time of arrival of the stress waves at two different observation points and thus locate the origin of the acoustic emission. During a 3 point-bend-test critical crack growth begins at about 80% of the fracture load.     

A Miniature Scintillation Probe for Use in Powder Tracer Studies

ABSTRACT

A miniaturized scintillation probe has been used to follow the movement of particles tagged with radioactive isotopes Ir-192 and Tm-170. The small size of the probe (2 mm x 10 cm) has overcome two traditional powder monitoring problems, that of removing a representative sample and of causing gross bed disturbance by inserting a large probe. The miniature probe may be used in situ or on-line; it gives an extremely rapid response. Two examples of the use of the probe are briefly presented. It has been used to follow the axial mixing in a drum mixer and to follow the segregation of particles due to vibration. The probe has many potential uses for monitoring the progress of particles in pastes, doughs, slurries, and suspensions, in addition to dry powders.     

The specific type IV phosphodiesterase inhibitor rolipram suppresses tumor necrosis factor-alpha production by human mononuclear cells

Compounds suppressing the production of tumor necrosis factor-alpha are protective in animal models of septic shock. Recent studies demonstrated a beneficial effect of xanthine derivatives, which suppress tumor necrosis factor-alpha production by acting as non-specific cAMP phosphodiesterase inhibitors. In this experiment we tested the effect of (+/-)-rolipram (racemate) and its enantiomers on human mononuclear cells stimulated with lipopolysaccharide (LPS). Rolipram has a phenyl-pyrrolidinone structure, unrelated to the methylxanthines, and acts as a specific inhibitor of the type IV phosphodiesterase. Our results identify rolipram as a remarkably potent suppressor of the LPS-induced synthesis of tumor necrosis factor-alpha. When compared to the non-specific inhibitor pentoxifylline, the IC50 of (+/-)-rolipram (130 nM) is more than 500 times lower. The influence of rolipram on tumor necrosis factor-alpha production depended on the steric configuration of the molecule, since the (-)-enantiomer exhibited a five times lower IC50 than the (+)-enantiomer. The inhibitory effect of all substances tested is selective for tumor necrosis factor-alpha rather than interleukin-1 beta, since interleukin-1 beta production is only slightly influenced.     

Asset pricing with dynamic programming

The study of asset price characteristics of stochastic growth models such as the risk-free interest rate, equity premium, and the Sharpe-ratio has been limited by the lack of global and accurate methods to solve dynamic optimization models. In this paper, a stochastic version of a dynamic programming method with adaptive grid scheme is applied to compute the asset price characteristics of a stochastic growth model. The stochastic growth model is of the type as developed by [Brock and Mirman (1972), Journal of Economic Theory, 4, 479–513 and Brock (1979), Part I: The growth model (pp. 165–190). New York: Academic Press; The economies of information and uncertainty (pp. 165–192). Chicago: University of Chicago Press. (1982). It has become the baseline model in the stochastic dynamic general equilibrium literature. In a first step, in order to test our procedure, it is applied to this basic stochastic growth model for which the optimal consumption and asset prices can analytically be computed. Since, as shown, our method produces only negligible errors, as compared to the analytical solution, in a second step, we apply it to more elaborate stochastic growth models with adjustment costs and habit formation. In the latter model preferences are not time separable and past consumption acts as a constraint on current consumption. This model gives rise to an additional state variable. We here too apply our stochastic version of a dynamic programming method with adaptive grid scheme to compute the above mentioned asset price characteristics. We show that our method is very suitable to be used as solution technique for such models with more complicated decision structure.      

Liver and spleen enhancement after intravenous injection of carboxydextran magnetite: effect of dose,delay of imaging,and field strength in anex vivo model

It has been predicted that liver and spleen enhancement after administration of superparamagnetic contrast agents may be different, depending on the strength of the main magnetic field. With the use of anex vivo model, we investigated at 0.3, 0.5, and 1.5 T the effects on liver and spleen signal intensity of 5, 15, and 45 µmol/kg body weight of dextran magnetite (SHU 555A) in 54 rats. Nine rats served as controls. At different time delays since injection, the animals were killed, and after perfusion with saline, the liver, brain, and spleen were fixed in formalin. The specimens were embedded in an agar gel matrix and imaged with inversion recovery T1-weighted, proton density spin echo, and T2*-weighted gradient recalled echo (GRE) sequences. At each magnetic field strength, peak liver and spleen signal loss increased with increasing dose of the contrast medium. Signal loss was significantly more conspicuous after a dose of 15 than 5 µmol/kg body weight, but not after a dose of 45 compared with 15 µmol/kg. No signal change was observed in the brain. GRE images showed higher enhancement than proton density-weighted spin echo and inversion recovery images but were noisier. The enhancement showed a plateau between 30 min and 24 hours. Only the signal decrease of the liver after a low dose of contrast medium on GRE images was significantly higher (p<0.01) at 1.5 than at 0.5 and 0.3 T. Other differences in respect to the field strength were less significant (p<0.05) or nonsignificant. Differences in the spleen enhancement were nonsignificant. SHU 555A at a dose of 15 µmol/kg is an efficient intracellular contrast agent for liver and spleen at low, mid, and high field strength. Proton density spin echo images are probably the sequence of choice to exploit SHU 555A contrast effects and a wide time window for imaging after its intravenous injection does exist.