Crystal structure of 1-bis(((1R,2S,5R)-2-isopropyl-5-methylcyclohexyl) cyclopentadienyl)-1-trimethylphosphine-2,3-bis(trimethylsilyl) -1-hafnacycloprop-2-ene-hexane (1:0.5), (HfC8H18Si 2)(C15H22)2(PC3H 9) · 0.5C6H14

C44H78HfPSi2, tetragonal, P4 1212 (no. 92), a = 14.9634(2) Å, c = 44.9270(8) Å, V = 10059.3 Å3, Z = 8, Rgt(F) = 0.026, wRref(F2) = 0.073, T = 200 K. © by Oldenbourg Wissenschaftsverlag, München

Laser Additive Manufacturing of Gas Permeable Structures

Laser additive manufacturing offers a variety of new design possibilities. In mold making laser additive manufactured inserts with conformal cooling channels are already state of the art. Pneumatic ejectors for injection molds are a new application for laser additive manufacturing. The pneumatic ejectors require a durable gas permeable material. This material is produced by placing the scan vectors for the laser additive manufacturing process in a defined pattern. Trials with different plastics proofed the function and reliability of the pneumatic ejector concept in the injection molding cycle

Cyrhetrenylaniline and new organometallic phenylimines derived from 4- and 5-nitrothiophene: Synthesis, characterization, X-Ray structures, electrochemistry and in vitro anti-T. brucei activity

A novel series of cyrhetrenyl (3a-4a) and ferrocenyl (3b-4b) Schiff bases were synthesized through a condensation reaction, between the known 4-ferrocenylaniline (2b) or the unreported 4-cyhretrenylaniline (2a) with 4- or 5-nitrothiophenecarboxaldehyde. The structure of 2a and the new Schiff bases have been elucidated using conventional spectroscopic techniques (FT-IR, 1H and 13C NMR), mass spectrometry, and single-crystal X-ray diffraction analysis of compounds 2a, 4a and 3b. Cyclic voltammetry of organometallic phenylimines derived from 5-nitrothiophene showed NO2 group reduction potentials (E1/2z 0.575 V) that were more anodic than those registered for their 4-nitro analogues (E1/2z 0.981 V). All organometallic imines were tested against the bloodstream form of Trypanosoma brucei. Evaluation indicated that the most active complexes are the 5-nitrothiophene derivatives, 4a, which were remarkably more active than nifurtimox. In addition, complex 4b resulted in less toxicity to host L6 cells than nifurtimox. The results revealed that the electronic effects of cyrhetrene and ferrocene are not an influential factor in E1/2 and anti-Trypanosoma brucei activity for these new imines, which is probably due to the non-coplanarity of the [(h5-C5H4)-C6H4-N=CH-(C4H2S)] system

(Z)-3-(4-Bromo­anilino)-1-ferrocenylbut-2-en-1-one

In the title compound, [Fe(C5H5)(C15H13BrNO)], formed from the reaction of ferrocenoylacetone and 4-bromo­aniline, the mol­ecular structure is stabilized by an intra­molecular N—H⋯O hydrogen bond between the amine and carbonyl groups

Nanostructural effects and interface magnetism in Co/Pd multilayers

A series of Co/Pd multilayers were made by dc magnetron sputter deposition on Al foil substrates. For these multilayered samples, Co layer thicknesses were less than 4 Å and Pd layers were varied from 4 to 22 Å. Sputtering rates were controlled by either sputtering power (10–50 W) or Ar sputtering pressure (3–15 mTorr). In both cases, lower deposition rates yielded higher perpendicular coercivity up to 2.6 kOe. Structures of the samples were studied using conventional θ -2θ x-ray diffractometry (XRD). It has been found that magnetic properties such as coercivity and saturation magnetization are sensitive to interfacial structures. A nanostructural model including interfacial parameters such as alloy layer composition is discussed and compared with the magnetization data. Both XRD and magnetization measurements show that the interfaces become more diffuse at higher sputtering pressures. Journal of Applied Physics is copyrighted by The American Institute of Physics

Constraints of the variation of fundamental couplings and sensitivity of the equation of state of dense matter

We discuss the coupled variations of the gravitational, strong and electroweak coupling constants and the current knowledge of the nuclear equation of state based on heavy ion collision experiments and neutron star mass-radius relationship. In particular we focus in our description on phenomenological parameters, $R$, relating variations in the quantum chromodynamics scale $\Lambda_{QCD}$ and the fine structure constant $\alpha$, and $S$, relating variation of $v$, the Higgs vacuum expectation value and the Yukawa couplings, $h$, in the quark sector. This parametrization is valid for any model where gauge coupling unification occurs at some (unspecified) high energy scale. From a physically motivated set of equations of state for dense matter we obtain the constrained parameter phase space $(R, S)$ in high density nuclear environments. This procedure is complementary to (although currently less powerful than) those used in low density conditions. For variations of $\Delta \alpha/\alpha=0.005$ we find that the obtained constrained parameter lies on a strip region in the $(R, S)$ plane that partially overlaps some of the allowed values of parameters derived from primordial abundances. This may be of interest in the context of unification scenarios where a dense phase of the universe may have existed at early times.Comment: 16 pages, 7 figs, accepted for publication in Phys. Lett.

Diquark Condensates and Compact Star Cooling

The effect of color superconductivity on the cooling of quark stars and neutron stars with large quark cores is investigated. Various known and new quark-neutrino processes are studied. As a result, stars being in the color flavor locked (CFL) color superconducting phase cool down extremely fast. Quark stars with no crust cool down too rapidly in disagreement with X-ray data. The cooling of stars being in the N_f =2 color superconducting (2SC) phase with a crust is compatible with existing X-ray data. Also the cooling history of stars with hypothetic pion condensate nuclei and a crust does not contradict the data.Comment: 10 pages, 5 figures, accepted for publication in Ap

Phase diagrams in nonlocal PNJL models constrained by Lattice QCD results

Based on lattice QCD-adjusted SU(2) nonlocal Polyakov--Nambu--Jona-Lasinio (PNJL) models, we investigate how the location of the critical endpoint in the QCD phase diagram depends on the strenght of the vector meson coupling, as well as the Polyakov-loop (PL) potential and the form factors of the covariant model. The latter are constrained by lattice QCD data for the quark propagator. The strength of the vector coupling is adjusted such as to reproduce the slope of the pseudocritical temperature for the chiral phase transition at low chemical potential extracted recently from lattice QCD simulations. Our study supports the existence of a critical endpoint in the QCD phase diagram albeit the constraint for the vector coupling shifts its location to lower temperatures and higher baryochemical potentials than in the case without it.Comment: 23 pages, 10 figures. Version accepted in Phys. Part. Nucl. Lett. (to appear), references adde

Expression of the ggpPS gene for glucosylglycerol biosynthesis from Azotobacter vinelandii improves the salt tolerance of Arabidopsis thaliana

Many organisms accumulate compatible solutes in response to salt or desiccation stress. Moderate halotolerant cyanobacteria and some heterotrophic bacteria synthesize the compatible solute glucosylglycerol (GG) as their main protective compound. In order to analyse the potential of GG to improve salt tolerance of higher plants, the model plant Arabidopsis thaliana was transformed with the ggpPS gene from the γ-proteobacterium Azotobacter vinelandii coding for a combined GG-phosphate synthase/phosphatase. The heterologous expression of the ggpPS gene led to the accumulation of high amounts of GG. Three independent Arabidopsis lines showing different GG contents were characterized in growth experiments. Plants containing a low (1–2 μmol g−1 FM) GG content in leaves showed no altered growth performance under control conditions but an increased salt tolerance, whereas plants accumulating a moderate (2–8 μmol g−1 FM) or a high GG content (around 17 μmol g−1 FM) showed growth retardation and no improvement of salt resistance. These results indicate that the synthesis of the compatible solute GG has a beneficial effect on plant stress tolerance as long as it is accumulated to an extent that does not negatively interfere with plant metabolism