Dynamic van der Waals Theory of two-phase fluids in heat flow

We present a dynamic van der Waals theory. It is useful to study phase separation when the temperature varies in space. We show that if heat flow is applied to liquid suspending a gas droplet at zero gravity, a convective flow occurs such that the temperature gradient within the droplet nearly vanishes. As the heat flux is increased, the droplet becomes attached to the heated wall that is wetted by liquid in equilibrium. In one case corresponding to partial wetting by gas, an apparent contact angle can be defined. In the ther case with larger heat flux, the droplet completely wets the heated wall expelling liquid.Comment: 6pages, 8figure

Single-experiment-detectable multipartite entanglement witness for ensemble quantum computing

In this paper we provide an operational method to detect multipartite entanglement in ensemble-based quantum computing. This method is based on the concept of entanglement witness. We decompose the entanglement witness for each class of multipartite entanglement into nonlocal operations in addition to local measurements. Individual single qubit measurements are performed simultaneously, hence complete detection of entanglement is performed in a single run experiment. This approach is particularly important for experiments where it is operationally difficult to prepare several copies of an unknown quantum state and in this sense the introduced scheme in this work is superior to the generally used entanglement witnesses that require a number of experiments and preparation of copies of quantum state.Comment: 9 pages, 5 figures, minor changes have been mad

Conditional quantum thermometry -- enhancing precision by measuring less

Taking accurate measurements of the temperature of quantum systems is a challenging task. The mathematical peculiarities of quantum information make it virtually impossible to measure with infinite precision. In the present letter, we introduce a generalize thermal state, which is conditioned on the pointer states of the available measurement apparatus. We show that this conditional thermal state outperforms the Gibbs state in quantum thermometry. The origin for the enhanced precision can be sought in its asymmetry quantified by the Wigner-Yanase-Dyson skew information. This additional resource is further clarified in a fully resource-theoretic analysis, and we show that there is a Gibbs-preserving map to convert a target state into the conditional thermal state. Finally, we relate the quantum J-divergence between the conditional thermal state and the same target state to quantum heat.Comment: 5+6 pages, 2 figure

An electron microscopic study of gas condensates in the system Mg-Si-O-H

Condensates of MgSiO_3 and SiO_2 from a gas formed by evaporation of enstatite at an H_2 pressure of 4.4×10^ bar and a temperature of 1525℃ by B. O. MYSEN and I. KUSHIRO (Am. Mineral. (in press), 1988) and I. KUSHIRO and B. O. MYSEN (Advances in Physical Geochemistry, New York, Springer (in press), 1988) were investigated with an analytical transmission electron microscope (ATEM), a scanning electron microscope (SEM) and an electron probe microanalyzer (EPMA). With decreasing temperature at an approximately constant total pressure the Mg/(Mg+Si) atomic ratio of the condensate (mixture of MgSiO_3 and SiO_2 polymorphs) decreases first, then increases, and finally reaches a constant value. This compositional change of the condensate is inconsistent with the equilibrium condensation model. The TEM studies suggest that metastable condensation of coesite and probably of protoenstatite and cristobalite took place. Coesite probably condensed by heterogeneous nucleation on protoenstatite. Fibrous quartz was also formed by heterogeneous nucleation on molybdenum fibers which condensed from a molybdenum vapor by a partial evaporation of a Knudsen cell used in the experiment. Heterogeneous nucleation might have played an important role in condensation process in the solar nebula. The texture of the experimental clinopyroxene condensate is different from that in interplanetary dust particles (J. P. BRADLEY et al., Nature, 301,473,1983)

Formation of Pillars at the Boundaries between H II Regions and Molecular Clouds

We investigate numerically the hydrodynamic instability of an ionization front (IF) accelerating into a molecular cloud, with imposed initial perturbations of different amplitudes. When the initial amplitude is small, the imposed perturbation is completely stabilized and does not grow. When the initial perturbation amplitude is large enough, roughly the ratio of the initial amplitude to wavelength is greater than 0.02, portions of the IF temporarily separate from the molecular cloud surface, locally decreasing the ablation pressure. This causes the appearance of a large, warm HI region and triggers nonlinear dynamics of the IF. The local difference of the ablation pressure and acceleration enhances the appearance and growth of a multimode perturbation. The stabilization usually seen at the IF in the linear regimes does not work due to the mismatch of the modes of the perturbations at the cloud surface and in density in HII region above the cloud surface. Molecular pillars are observed in the late stages of the large amplitude perturbation case. The velocity gradient in the pillars is in reasonably good agreement with that observed in the Eagle Nebula. The initial perturbation is imposed in three different ways: in density, in incident photon number flux, and in the surface shape. All cases show both stabilization for a small initial perturbation and large growth of the second harmonic by increasing amplitude of the initial perturbation above a critical value.Comment: 21 pages, 8 figures, accepted for publication in ApJ. high resolution figures available upon reques

Synthesis and characterisation of some metal complexes of hybrid phosphorus-nitrogenligands: the crystal structure of 1-(diphenylphosphino)-2-(2-pyridyl)ethane cobalt(II) chloride

Some iron(II), cobalt(II) and copper(II) complexes of the hybrid ligand 1-(diphenylphosphino)-2-(2-pyridyl)ethane (dppe) and diphenyl-2-pyridylphosphine (dppp) have been synthesised and characterised. Analyses suggest tetrahedral structures in which the metal atoms are bonded to two chlorine atoms and to both phosphorus and nitrogen atoms for 1-(diphenylphosphino)-2-(2-pyridyl)ethane on one hand and on the other hand, bonding is through the nitrogen atoms of two molecules of diphenyl-2-pyridylphosphine, which acts as a monodentate ligand. The crystal structure of 1-(diphenylphosphino)-2-(2-pyridyl)ethane cobalt(II) chloride shows a pseudo-tetrahedral structure in which the aminophosphine is bonded to the cobalt centre through both the phosphorus and nitrogen atoms, forming a 6-membered ring. KEY WORDS: Aminophosphines, Metal complexes, Cobalt(II) complex, Crystal structure  Bull. Chem. Soc. Ethiop. 2008, 22(2), 253-260

Multiple nearest-neighbor exchange model for the frustrated magnetic molecules Mo72Fe30 and Mo72Cr30

Our measurements of the differential susceptibility dM/dH of the frustrated magnetic molecules Mo72Fe30 and Mo72Cr30 reveal a pronounced dependence on magnetic field (H) and temperature (T) in the low H - low T regime, contrary to the predictions of existing models. Excellent agreement with experiment is achieved upon formulating a nearest-neighbor classical Heisenberg model where the 60 nearest-neighbor exchange interactions in each molecule, rather than being identical as has been assumed heretofore, are described by a two-parameter probability distribution of values of the exchange constant. We suggest that the probability distribution provides a convenient phenomenological platform for summarizing the combined effects of multiple microscopic mechanisms that disrupt the idealized picture of a Heisenberg model based on a single value of the nearest-neighbor exchange constant.Comment: 8 pages, 5 figure

New records and observations of macroalgae and associated pathogens from the Falkland Islands, Patagonia and Tierra del Fuego

Subantarctic and Antarctic regions remain little explored with regards to their seaweed diversity. This study is based upon collections in the early 1970s and 2007–2013. It is supported by sequencing COI (mitochondrial cytochrome oxidase I) and reports new records for four species of brown algae Hincksia granulosa, Hincksia sandriana, Myriotrichia clavaeformis, Syringoderma australe), four red algae (Erythrotrichia carnea, Paraglossum salicifolium, Phycodrys antarctica, Plumariopsis eatonii), one green alga (Chaetomorpha aerea) and of the oomycete Anisolpidium ectocarpii. A further four brown algae are reported at genus level and discussed (Cladostephus sp., Colpomenia sp., Dictyota sp., Punctaria sp.). Observations of the biology of three brown algal taxa (Cladothele decaisnei, Geminocarpus geminatus, Halopteris obovata) from the region are also reported here

Possible steps of complete disassembly of post-termination complex by yeast eEF3 deduced from inhibition by translocation inhibitors.

Ribosomes, after one round of translation, must be recycled so that the next round of translation can occur. Complete disassembly of post-termination ribosomal complex (PoTC) in yeast for the recycling consists of three reactions: release of tRNA, release of mRNA and splitting of ribosomes, catalyzed by eukaryotic elongation factor 3 (eEF3) and ATP. Here, we show that translocation inhibitors cycloheximide and lactimidomycin inhibited all three reactions. Cycloheximide is a non-competitive inhibitor of both eEF3 and ATP. The inhibition was observed regardless of the way PoTC was prepared with either release factors or puromycin. Paromomycin not only inhibited all three reactions but also re-associated yeast ribosomal subunits. On the other hand, sordarin or fusidic acid, when applied together with eEF2/GTP, specifically inhibited ribosome splitting without blocking of tRNA/mRNA release. From these inhibitor studies, we propose that, in accordance with eEF3\u27s known function in elongation, the release of tRNA via exit site occurs first, then mRNA is released, followed by the splitting of ribosomes during the disassembly of post-termination complexes catalyzed by eEF3 and ATP