A new program for DSC purity analysis

DSC purity determinations have become very popular today [3]. The latest edition of the Mettler software package for thermal analysis, TA72.S GraphWare, now comprises a powerful purity evaluation program. It is based on the simultaneous calculation of the mole ratio of the sum of the eutectic impurities, the melting point of the pure component, the melting point of the substance present and the linearization term. The portion of the melting curve investigated is selected appropriately.Experience has shown, that the applied heating rate is a very important parameter which influences the duration of the measurement and also the possible exposure to elevated temperature where decomposition can become a problem and last but not least the accuracy of the calculated impurity value.

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Zusammenfassung Die DSC-Reinheitsbestimmung ist heute eine weit verbreitete Methode, die mit einer einzigen Messung und unter Verwendung geeigneter Auswerteprogramme eine Bestimmung der absoluten eutektischen Reinheit einer Probe zulÄsst. Gleichzeitig können weitere thermodynamische Daten bestimmt werden, wie Schmelzpunkt der Probensubstanz und der reinen Hauptkomponente und die Schmelzenthalpie der Probe.Durch experimentelle Befunde konnte gezeigt werden, dass die Wahl der Aufheizrate kritisch ist in bezug auf die Genauigkeit und die Signifikanz der ermittelten Daten.

     

The Glass Transition of Water and Aqueous Systems

After a brief introduction of the terms supercooling, amorphous solid state, glass transition and devitrification, the known ways of production of amorphous solid water are discussed. DSC experiments with quench cooled aqueous solutions show the phenomenon of glass transition and devitrification.This revised version was published online in November 2005 with corrections to the Cover Date.     

Foreword

At the hadron experimental hall of J-PARC, a lot of interesting experiments on strangeness nuclear physics and hadron physics are going to be carried out. Here I introduce several examples, and report the status of the J-PARC.     

Validation of a coupled FE-model for the simulation of methane oxidation via thermal imaging

To simulate the processes of methane oxidation in landfill cover layers, a new computational model was created. The purpose of the model is to allow a forecast on the performance of methanotrophic activity in landfill cover layers under changing environmental conditions. Therefore, a thermodynamic consistent model based on the well-known Theory of Porous Media (TPM) combined with the mixture theory was developed, which analyzes the relevant gas productions of methane, oxygen and carbon dioxide. Diffusion, advection and conversion processes are considered as well as the energy production during methane oxidation. With the help of the thermal imaging technique a new experimental setup was developed in order to validate the coupled model in terms of the heat generation. (© 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

The ASACUSA CUSP: an antihydrogen experiment

In order to test CPT symmetry between antihydrogen and its counterpart hydrogen, the ASACUSA collaboration plans to perform high precision microwave spectroscopy of ground-state hyperfine splitting of antihydrogen atom in-flight. We have developed an apparatus (“cusp trap”) which consists of a superconducting anti-Helmholtz coil and multiple ring electrodes. For the preparation of slow antiprotons and positrons, Penning-Malmberg type traps were utilized. The spectrometer line was positioned downstream of the cusp trap. At the end of the beamline, an antihydrogen beam detector was located, which comprises an inorganic Bismuth Germanium Oxide (BGO) single-crystal scintillator housed in a vacuum duct and surrounding plastic scintillators. A significant fraction of antihydrogen atoms flowing out the cusp trap were detected.     

Search for kaonic nuclear state, K − pp, in the p + p → X + K + reaction with FOPI

We search for the most fundamental kaonic nuclear state, K ^??? pp by employing the reaction p?+?p→K ^?+??+?X at 3.0 GeV incident beam energy. The experiment makes use of the SIS-18 synchrotron and the ~4π acceptance FOPI apparatus in the cave-B at the GSI, Darmstadt, Germany and aims to collect full kinematics information of the reaction. We look for a signature of the X (?≡?K ^??? pp) in both missing mass spectrum by measuring K ^?+?, and invariant mass spectrum by measuring decay particles; X?→?Λ?+?p. The experiment is planned to take place in 2009.     

Hyperfine structure of antiprotonic helium revealed by a laser-microwave-laser resonance method

Using a newly developed laser-microwave-laser resonance method, we observed a pair of microwave transitions between hyperfine levels of the (n,L)=(37,35) state of antiprotonic helium. This experiment confirms the quadruplet hyperfine structure arising from the interaction of the antiproton orbital angular momentum, the electron spin and the antiproton spin as predicted by Bakalov and Korobov. The measured frequencies of nu(+)(HF)=12.895 96+/-0.000 34 GHz and nu(-)(HF)=12.924 67+/-0.000 29 GHz agree with recent theoretical calculations on a level of 6x10(-5).     

Primary populations of metastable antiprotonic (4)He and (3)He atoms

Initial distributions of metastable antiprotonic (4)He and (3)He atoms over principal (n) and angular momentum (l) quantum numbers have been deduced using laser spectroscopy experiments. The regions n = 37-40 and n = 35-38 in the two atoms account for almost all of the observed fractions [(3.0 +/- 0.1)% and (2.4 +/- 0.1)%] of antiprotons captured into metastable states.