Stahl und Eisen

Ohne Zusammenfassung     

Magnetic moment of the 5/2−1/2[541] ground state of 14h 185Ir

The magnetic and electric hyperfine splitting frequencies ¦gμ _N B _HF/h¦ ande ² qQ/h of the 5/2^?1/2[541] ground state of 14h ¹⁸⁵Ir in Ni were measured with nuclear magnetic resonance on oriented nuclei to be 360.8(7) MHz and +6.7(2.0) MHz, respectively. The ground state magnetic dipole moment and electric quadrupole moment of¹⁸⁵Ir are deduced to be ¦μ¦=2.601 (14)μ _N andQ=?1.9(5)b, taking values for the hyperfine field and electric field gradient of B_HF=?454.9 (2.3) kG and eq=?0.151(4) × 10¹⁷ V/cm², respectively. The negative quadrupole moment is in agreement with nuclear-orientation data and proves again theI ^π K=5/2^? 1/2 ground state configuration.     

The hyperfine field of sodium in iron

The hyperfine field of NaFe has been measured using Low Temperature Nuclear Orientation of cold implanted²⁴Na. The combination of both the γ-and β-anisotropies yields information on the implantation fraction of Na in Fe. Furthermore, an, upper limit for the relaxation time of Na in Fe could be deduced.     

Synthesen von Heterocyclen, 86. Mitt.: Über die Reaktion von Oxalylchlorid mit hydroaromatischen Ketonanilen

Zusammenfassung Cyclanon-anile reagieren mit Oxalylchlorid in einfacher Weise zu 1-Phenyl-4,5-polymethylen-2,3-dion-pyrrolen.

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The anils of cyclanones react with oxalyl chloride yielding 1-phenyl-4,5-polymethylene-pyrrol-2,3-dion.

     

Investigation of the “50 K-transition” in PdH0.73 by γ-ray and neutron diffraction

Rocking curves of the (111)-reflection in a PdH_0.73 single crystal have been measured with 412 keV γ-rays during an ageing experiment at 50 K up to 260 h. The width (variance) shows an overall increase of 1.5% ± 0.3% and the integrated intensity a maximum at 100 h.An investigation at superstructure points in the same PdH_0.73 crystal was made using neutron scattering. An enhancement of the elastic diffuse scattering has been found at the $\text{(1}\text{1}\text{2}\text{0)}$ and (110)-positions after an ageing at 54 K up to 300 h. The intensity ratio to the fundamental (002)-reflection is 10^-4. It is concluded that below the anomaly temperature a local ordering of the hydrogen atoms occurs and the growth of the ordered zones slows down after 100 h ageing.     

Activated carbon obtained from sapelli wood sawdust by microwave heating for o-cresol adsorption

Research on Chemical Intermediates - Activated carbon (AC) was prepared from sapelli wood sawdust using a microwave heating process. The biomass was mixed with inorganic components...     

Dimensioning of fins with general nonlinear cooling laws

An analytic treatment of rectangular and triangular fins is given, the cooling laws are polynoms of the fin temperature. Closed formulas could be found for the fin temperature, for the dissipated heat flux and for the optimization of the fin dimensions with respect to the mass. The usefulness of the relations in fin application and in heat transfer research is discussed. The used quasilinearization technique outlined in the paper may be of interest for other nonlinear heat transfer problems.

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Zusammenfassung Es wird der Fall betrachtet, daß an der Oberfläche von Kühlrippen ein nichtlinearer Wärmeaustausch stattfindet, der durch ein Polynom der Rippentemperatur beschrieben wird. Durch Anwendung der Quasilinearisierungsmethode erhält man geschlossene Formeln für die Temperaturverläufe und die Wärmeströme in Rechteck- und Dreiecksrippen und für ihre massenoptimale Dimensionierung. Die Beziehungen werden zur Untersuchung nichtlinearer Wärmeübertragungsverhältnisse und in der Raumfahrt- und Reaktortechnologie verwendet. Die Quasilinearisierungstechnik läßt sich auch für andere nichtlineare Probleme verwenden.

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Dedicated to Prof. Dr. U. Grigull, Munich, to his 60th birthday.

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Best thanks to Mr. Prof. Dr. H. Ruppe, Space technology department of the Technische Universität München, Germany, for revision of the paper.     

CHARMM‐GUI Membrane Builder toward realistic biological membrane simulations

CHARMM‐GUI Membrane Builder, http://www.charmm‐gui.org/input/membrane , is a web‐based user interface designed to interactively build all‐atom protein/membrane or membrane‐only systems for molecular dynamics simulations through an automated optimized process. In this work, we describe the new features and major improvements in Membrane Builder that allow users to robustly build realistic biological membrane systems, including (1) addition of new lipid types, such as phosphoinositides, cardiolipin (CL), sphingolipids, bacterial lipids, and ergosterol, yielding more than 180 lipid types, (2) enhanced building procedure for lipid packing around protein, (3) reliable algorithm to detect lipid tail penetration to ring structures and protein surface, (4) distance‐based algorithm for faster initial ion displacement, (5) CHARMM inputs for P₂₁ image transformation, and (6) NAMD equilibration and production inputs. The robustness of these new features is illustrated by building and simulating a membrane model of the polar and septal regions of E. coli membrane, which contains five lipid types: CL lipids with two types of acyl chains and phosphatidylethanolamine lipids with three types of acyl chains. It is our hope that CHARMM‐GUI Membrane Builder becomes a useful tool for simulation studies to better understand the structure and dynamics of proteins and lipids in realistic biological membrane environments. © 2014 Wiley Periodicals, Inc.     

Switching between Local and Global Aromaticity in a Conjugated Macrocycle for High‐Performance Organic Sodium‐Ion Battery Anodes

Aromatic organic compounds can be used as electrode materials in rechargeable batteries and are expected to advance the development of both anode and cathode materials for sodium‐ion batteries (SIBs). However, most aromatic organic compounds assessed as anode materials in SIBs to date exhibit significant degradation issues under fast‐charge/discharge conditions and unsatisfying long‐term cycling performance. Now, a molecular design concept is presented for improving the stability of organic compounds for battery electrodes. The molecular design of the investigated compound, [2.2.2.2]paracyclophane‐1,9,17,25‐tetraene (PCT), can stabilize the neutral state by local aromaticity and the doubly reduced state by global aromaticity, resulting in an anode material with extraordinarily stable cycling performance and outstanding performance under fast‐charge/discharge conditions, demonstrating an exciting new path for the development of electrode materials for SIBs and other types of batteries.