12 research outputs found
KulturminnesvÄrdsprogram
Program för vÄrd av kulturminnen hÄller pÄ att tas fram i hela landet. De kan ses som en direkt följd av kulturminnesvÄrdens engagement i den fysiska riksplaneringen. Programarbetet har framskridit pÄ olika sÀtt, medskilda metoder och tidsplaner. I nÄgra lÀn har innehÄllet i programmen förts ut till en större krets genom affischer, utstÀllningar och studiematerial
Determination and evaluation of pressure-volume-temperature relationships of some halogenated hydrocarbons and their binary mixtures : an experimental and theoretical study
Density for Water + Ethylenediamine at Temperatures between 283 and 353 K
The density for mixtures of ethylenediamine (EDA) and water at 0.2 MPa was measured with a vibrating tube densitometer in the temperature range of 283 K to 353 K at intervals of 10 K. The entire composition range was covered with intervals of molar fractions of 10 %. The excess volume has a minimum at a molar fraction of water of 59 %, corresponding to a maximum at 69 % in the departure from additivity in density. The variation with temperature in excess volume is small, but for density it is complex. The temperature dependence in density is well described by combining a Redlich-Kister model for excess volume without temperature dependent parameters with models for the pure component densities
Aspects on metal ion distribution models in pulp washing simulation
The closure of the liquid system in a pulp mill has increased the concentration of metal ions in the process as compared to traditional plants. These ions commonly referred to as non-process elements, NPE, enter the pulp mill with the wood chips, the water supply and the pulping chemicals. The presence of these ions may lead to various problems, e.g. incrust formation, filtration failures and reduced bleaching efficiency and the objective of the pulp washing operation is to remove a major part of these metal ions from the pulp.
The objective of this work was to study the influence of sorption of metal ions on the simulation of pulp washing.
A process simulator, ASPEN Plus, has been used to describe the different steps in a displacement drum washer. In order to take account of the sorption of metal ions on the pulp fibres blocks with FORTRAN subroutines have been developed and included. The simulations studies show that the washing results are quite similar for all models at high concentration levels. Hence, the adsorption does not contribute significantly except for low concentration cases. The influence of the sorption model and thus also the choice of model is important only in washing stages where the concentration of ions is very low.
Comparison with data for an industrial displacement drum washer indicated the usefulness of the simulation model in evaluation of the operation. It was found that the displacement-washing step was far from ideal probably due to uneven liquid distribution and formation problems. For washing of solids other than paper pulp, e.g. lime mud, the effect of sorption metal ions on the washing result is less pronounced and a simpler model can be used with good results
Determination of the Temperature Effect on Glycerol Nitration Processes Using the HYSYS Predictions and the Laboratory Experiment
Determinations of the temperature effect on glycerol nitration processes have been done with two methods: the HYSYS predictions and the laboratory experiment. The aim of this study was to compare prediction method and laboratory experiment method. The highest equilibrium conversion from HYSYS predictions was obtained in the range of equilibrium temperature of 10 to 20 °C. The laboratory experiments also described that nitration of glycerol with nitric acid should be carried out at reaction temperature of 10 to 20 °C. HYSYS that was used to predict the results of experiments in the laboratory can reduce the laboratory work with minimize the range of operating conditions studied. HYSYS exactly predict temperature of nitration of glycerol. The difference in conversion between two methods due to the equipment that was used in the experiments, procedure of experiments and the accuracy of analysis
Effects of toxic lithium levels on ECG : findings from the LiSIE retrospective cohort study
(1) Background: Few studies have explored the impact of lithium intoxication on the heart. (2) Methods: We examined electrocardiogram (ECG) changes associated with lithium intoxication in the framework of the LiSIE (Lithium-Study into Effects and Side Effects) retrospective cohort study. We analysed ECGs before, during, and after intoxication. (3) Results: Of the 1136 patients included, 92 patients had experienced 112 episodes of lithium intoxication. For 55 episodes, there was an ECG available at the time; for 48 episodes, there was a reference ECG available before and/or after the lithium intoxication. Lithium intoxication led to a statistically significant decrease in heart rate from a mean 76 beats/min (SD 16.6) before intoxication to 73 beats/min (SD 17.1) during intoxication (p = 0.046). QTc correlated only weakly with lithium concentration (Ï = 0.329, p = 0.014). However, in 24% of lithium intoxication episodes, there were QT prolongations. In 54% of these, QTc exceeded 500 ms; patients with chronic intoxications being more affected. (4) Conclusions: Based on summary statistics, effects of lithium intoxication on HR and QTc seem mostly discrete and not clinically relevant. However, QT prolongation can carry a risk of becoming severe. Therefore, an ECG should always be taken in patients presenting with lithium intoxication