Publications by authors named "Herak M"

The dimeric (gemini) as well as metallosurfactants exhibit enhanced physicochemical properties compared with conventional surfactants. By uniting the benefits of both, a series of novel dimeric metallosurfactants of the type (12-2-12)[MBr] (M = Co, Ni, Cu and Zn) was successfully prepared by the reaction of the dimeric surfactant bis(,-dimethyl--dodecyl)ethylene-1,2-diammonium dibromide, 12-2-12, and the MBr salt. Structures and magnetic properties of the materials were studied comprehensively in the solid state, while their micellization was explored in solution.

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The search for new materials for energy-efficient electronic devices has gained unprecedented importance. Among the various classes of magnetic materials driving this search are antiferromagnets, magnetoelectrics, and systems with topological spin excitations. Cu_{3}TeO_{6} is a material that belongs to all three of these classes.

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The AlpArray programme is a multinational, European consortium to advance our understanding of orogenesis and its relationship to mantle dynamics, plate reorganizations, surface processes and seismic hazard in the Alps-Apennines-Carpathians-Dinarides orogenic system. The AlpArray Seismic Network has been deployed with contributions from 36 institutions from 11 countries to map physical properties of the lithosphere and asthenosphere in 3D and thus to obtain new, high-resolution geophysical images of structures from the surface down to the base of the mantle transition zone. With over 600 broadband stations operated for 2 years, this seismic experiment is one of the largest simultaneously operated seismological networks in the academic domain, employing hexagonal coverage with station spacing at less than 52 km.

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Detailed single-crystal electron spin resonance (ESR) analysis of oxalamide complexes with halogen-bridged copper dimers, supported by X-ray, magnetic susceptibility, and powder ESR studies, is reported. Four complexes with two different ligands are synthesized: [CuL (μ-X)] and [CuL (μ-X)] , for which L =N-(l-alanine methyl ester)-N'-[(2-pyridine-2-yl)methyl]oxalamide and L =N-(l-valine methyl ester)-N'-[(2-pyridine-2-yl)methyl]oxalamide, for which X=Cl or Br. X-ray analysis shows that the geometry at each copper(II) ion is square pyramidal, whereas two pyramids share one base-to-apex edge with parallel basal planes.

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Employing complementary torque magnetometry and electron spin resonance on single crystals of herbertsmithite, the closest realization to date of a quantum kagome antiferromagnet featuring a spin-liquid ground state, we provide novel insight into different contributions to its magnetism. At low temperatures, two distinct types of defects with different magnetic couplings to the kagome spins are found. Surprisingly, their magnetic response contradicts the threefold symmetry of the ideal kagome lattice, suggesting the presence of a global structural distortion that may be related to the establishment of the spin-liquid ground state.

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dc Magnetic susceptibility measurements and the torque magnetometry were used to experimentally probe the symmetry of the antiferromagnetically (AFM) ordered state of Bi(2)CuO(4). A phenomenological approach to the anisotropy energy is used to model the angular dependence of torque for easy axis and easy plane anisotropy. Comparison of these results with the experimentally obtained curves leads to the conclusion that the antiferromagnetically ordered state in Bi(2)CuO(4) has an easy plane anisotropy with the c plane as an easy plane.

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The superovulatory response was followed up in 14 beef heifers by rectal palpation and by ultrasonographic examinations of the 28 ovaries, on day 7 after superovulation induced with PMSG (ovulation = day 0). Using a B-mode ultrasound instrument (Aloka Echo Camera SSD-210-DX II) equipped with a 5 MHz linear transrectal transducer, ultrasonography was found to be more reliable than rectal palpation. A significantly higher number of follicles (P < or = 0.

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The influence of vitamin D metabolites on intramuscular implants of bone matrix in rachitic rats was investigated. Recipient rats with rickets were injected daily with 1 alpha,25(OH)2D3,24(R),25(OH)2D3 or a combination of both metabolites. The presence of 1 alpha,25(OH)2D3 increased significantly the alkaline phosphatase activity, and slightly increased the activity of acid phosphatase.

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The influence of sodium ions on gastric absorption of calcium in ruminants was studied with regard to the accompanying anions. Bags made of the surviving mucous membrane of different compartments of bovine stomach were used for this purpose. The epithelial side of the mucous membrane always faced towards the inside of the bags.

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