Die Relation der Gleichheit angewendet auf den Elektromagnetismus und der Versuch vonKohlrausch undWeber

Zusammenfassung Die Meinungsverschiedenheiten über Begriffs-(Dimensions)-Systeme und Einheitensysteme verschwinden, wenn man folgendermaßen vorgeht: Erst muß man alle begrifflichen Definitionen der Größenarten besitzen und dann erst darf man die Einheiten festsetzen. Weiter muß man verlangen, daß die Gleichheitsaxione der Mathematik auch für die physikalischen Größen (und Größenarten) uneingeschränkt gelten sollen. Davon ausgehend wird gezeigt, daß undI=Q/t nicht die gleiche Größe sind (nicht der gleichen Größenart angehören), so daß ihr Quotient eine benannte (mit bezeichnete) Größe ist, die erstmalig von K. u. W. gemessen wurde. (1) drückt das universell gültige Ergebnis dieser Messung mit Hilfe verschiedener Einheiten aus. Die Willkürlichkeit dieser Einheiten ist wichtig. Dann wird das Verhältnis zwischen U dt und besprochen, das ebenfalls die gleiche von K. u. W. gemessene Größe wiedergibt. Die Anwendung der Gleichheitsaxiome auf benannte physikalische Größen führt zur Erkenntnis, daß die elektromagnetische. Verkettungskonstante weder gleich der Lichtgeschwindigkeit ist, noch der dimensionslosen Zahl 1 gleichgesetzt werden darf, und diese Erkenntnis enthält die Lösung der bestehenden Dimensionsschwierigkeiten auf dem Gebiet des Elektromagnetismus. Daraus folgt insbesondere, daß elektrische Größen und magnetische Größen sorgfältig unterschieden werden müssen.Mit 1 Abbildung     

The effect of triton on the electropolymerization of phenol; an investigation of the adhesion of coatings using surface enhanced Raman scattering (SERS)

The physical properties and adhesion of protective amine-modified polyoxyphenylene coatings, electroformed in situ onto metal substrates, have been found to be greatly improved by the addition of small quantities of the surfactant Triton to the electrolyte. The role of Triton is investigated using ir and Raman spectroscopic techniques. Triton is found to be present both at the metal substrate surface and dispersed throughout the polymer, becoming chemically bonded to the polymer after curing in air.     

Metallic Magnetic Calorimeters for X-Ray Spectroscopy

An increasing number of experiments employ low-temperature radiation/particle detectors which are based on a calorimetric detection scheme and operate at temperatures below 100 mK. Metallic magnetic calorimeters use a metallic paramagnetic temperature sensor in tight thermal contact with the X-ray absorber. The magnetization of the sensor is used to monitor the temperature change of the detector upon the absorption of single photons, which is proportional to the absorbed energy. Low-noise high-bandwidth dc superconducting quantum interference devices read out the small changes in magnetization. An energy resolution of DeltaE _FWHM = 2.7 eV was obtained for X-ray energies up to 6 keV.     

Separation of chiral biodegradation intermediates of linear alkylbenzenesulfonates by capillary electrophoresis

High-performance capillary electrophoresis (HPCE) with α-cyclodextrin as the chiral selector was applied to separate the enantiomers of p-sulfophenyl-2-butyrate (SP2B) and p-sulfophenyl-3-butyrate (SP3B), which occur as biodegradation intermediates of linear alkylbenzenesulfonates (LAS), the widely used anionic surfactants. With this analytical method, we studied the transformation of both SP3B enantiomers in a laboratory batch incubation with activated sewage sludge of a municipal wastewater treatment plant. (S)-(+)-SP3B and (R)-(-)-SP3B could be detected in mechanically treated sewage effluent. After enrichment on graphitized carbon black (Carbopack B), the extracts were analyzed by HPLC with UV diode array and fluorescence detection as well as by HPCE with UV diode array detection. Quantification of SP3B in a 24-h composite sample of primary sewage effluent yielded 34 μg/L (limit of detection, 0.1 μg/L) of the racemic mixture determined by HPLC and 18 μg/L of each enantiomer measured by HPCE (limit of detection, 1 μg/L).     

Engineering the Interlayer Spacing by Pre-Intercalation for High Performance Supercapacitor MXene Electrodes in Room Temperature Ionic Liquid

MXenes exhibit excellent capacitance at high scan rates in sulfuric acid aqueous electrolytes, but the narrow potential window of aqueous electrolytes limits the energy density. Organic electrolytes and room-temperature ionic liquids (RTILs) can provide higher potential windows, leading to higher energy density. The large cation size of RTIL hinders its intercalation in-between the layers of MXene limiting the specific capacitance in comparison to aqueous electrolytes. In this work, different chain lengths alkylammonium (AA) cations are intercalated into Ti₃C₂T_x, producing variation of MXene interlayer spacings (d-spacing). AA-cation-intercalated Ti₃C₂T_x (AA-Ti₃C₂), exhibits higher specific capacitances, and cycling stabilities than pristine Ti₃C₂T_x in 1 m 1-ethly-3-methylimidazolium bis-(trifluoromethylsulfonyl)-imide (EMIMTFSI) in acetonitrile and neat EMIMTFSI RTIL electrolytes. Pre-intercalated MXene with an interlayer spacing of ≈2.2 nm, can deliver a large specific capacitance of 257 F g⁻¹ (1428 mF cm⁻² and 492 F cm⁻³) in neat EMIMTFSI electrolyte leading to high energy density. Quasi elastic neutron scattering and electrochemical impedance spectroscopy are used to study the dynamics of confined RTIL in pre-intercalated MXene. Molecular dynamics simulations suggest significant differences in the structures of RTIL ions and AA cations inside the Ti₃C₂T_x interlayer, providing insights into the differences in the observed electrochemical behavior.     

Performance of bipolar trickle reactors

The performance of the bipolar trickle reactor has been studied using the electrochemical tracer technique. The theoretical equations for a semi-infinite dispersion model have been fitted to the experimental responses for the reactor with and without electrochemical reaction. Hydrodynamic parameters and reaction rate constants for copper deposition as functions of both the film Reynolds number and the dimensions of the bipolar trickle reactor have been derived and are interpreted in this paper.List of Symbols (Bo) Bodenstein number (uL _p/D) - C amplitude of the response curve (dimen sionless) - C ⁰ area under the response curve (mol cm^–3 s) - D dispersion coefficient (cm²s^–1) - h film thickness (cm) - k/h first order reaction rate constant (s^–1) - L length of the reactor (cm) - L _p length of the ring (cm) - n _r number of rings in a single layer - (Pe) Peclét number (uL/D) - (Re)_f film Reynolds number - r _i,r _o inner and outer radii of the ring (cm) - t time (s) - u mean liquid velocity (cm s^–1) - v volumetric liquid velocity (cm³ s^–1) - residence time (s) - kinematic viscosity (cm²s^–1)     

maXs: Microcalorimeter Arrays for High-Resolution X-Ray Spectroscopy at GSI/FAIR

Highly-charged heavy ions like U⁹¹⁺ provide unique conditions for the investigation of relativistic and quantum electrodynamical effects in strong electromagnetic fields. We present two X-ray detectors developed for high-resolution spectroscopy on highly-charged heavy ions. Both detectors consist of metallic magnetic calorimeters (MMCs) forming linear eight-pixel arrays. The first detector, maXs-20, is developed for the detection of X-rays up to 20?keV with an energy resolution below 3?eV. The second device, maXs-200, is designed for X-ray energies up to 200?keV with an energy resolution of 40?eV. The results of characterization measurements of single detectors of both arrays will be shown and discussed. In both cases, the performance of the detectors agrees well with their design values. Furthermore, we present a prototype MMC for soft X-rays with improved magnetic flux coupling. In first characterization measurements the energy resolution of this device was 2.0?eV (FWHM) for X-rays up to 6?keV.     

Microstructured Magnetic Calorimeter with Meander-Shaped Pickup Coil

In the last years metallic magnetic calorimeters (MMC) showed an energy resolution of a few eV for x-rays up to 10 keV. This makes MMCs a promising and powerful tool for many applications where photons or energetic massive particles have to be detected—like absolute activity measurements of radioactive isotopes, high resolution x-ray spectroscopy and x-ray fluorescence material analysis. However, in order to fulfill all requirements of these applications and to allow to reach the maximum resolving power a consequent micro-fabrication of the MMC detectors is needed. The micro-fabrication of metallic magnetic calorimeters requires reliable deposition and patterning processes for niobium structures with high critical currents and for paramagnetic sensors. As one result of our advances in microstructuring a fully microfabricated MMC which consists of a meander shaped niobium thin film pickup coil and a 3 μm thick sputter deposited paramagnetic Au:Er temperature sensor will be presented. Deposition of energy in the paramagnetic sensor causes a rise in temperature and results in a change of magnetization, which is measured by a low noise high bandwidth dc-SQUID. The sputter deposited Au:Er films we report on are working well and show thermodynamic properties close to the ones known from bulk material down to temperatures of 45 mK.