On the universal behavior of some thermodynamic properties along the whole liquid-vapor coexistence curve

When thermodynamic properties of a pure substance are transformed to reduced form by using both critical- and triple-point values, the corresponding experimental data along the whole liquid-vapor coexistence curve can be correlated with a very simple analytical expression that interpolates between the behavior near the triple and the critical points. The leading terms of this expression contain only two parameters: the critical exponent and the slope at the triple point. For a given thermodynamic property, the critical exponent has a universal character but the slope at the triple point can vary significantly from one substance to another. However, for certain thermodynamic properties including the difference of coexisting densities, the enthalpy of vaporization, and the surface tension of the saturated liquid, one finds that the slope at the triple point also has a nearly universal value for a wide class of fluids. These thermodynamic properties thus show a corresponding apparently universal behavior along the whole coexistence curve.     

The LHCf experiment at LHC

The LHCf experiment will be installed in 2007 on the LHC collider in the forward direction at ±140m from the ATLAS interaction point. The purpose of LHCf is to precisely measure the pion production cross section near zero degrees through the measurement of the photons produced in neutral pion decay. This measurement is crucial for the simulation of the showers induced in the atmosphere by very high energy cosmic rays; the 14 TeV energy available in the center of mass frame corresponds in fact to an equivalent energy of 10¹⁷ eV in the laboratory system. The paper focus on the proposed experiment and on the physics results that we expect from it.     

Interaction matrices as a first step toward a general model of radionuclide cycling: Application to the 137Cs behavior in a grassland ecosystem

Summary Interaction matrices, an expert semi quantitative method to identify multiple interactions among biotic and abiotic components of the ecosystem can be considered as a useful tool to develop conceptual models of the behavior of radionuclides in the environment. This systematic approach facilitates a comprehensible identification of the pathways of the main radionuclides and permits classification of the role of different ecosystem components in terms of cause-effect relationships. The method was applied to study the radiocesium migration in grassland ecosystem affected by the Chernobyl ¹³⁷Cs deposition. Interaction matrices have been simultaneously utilized to explore the dynamic changes on the radiocesium migration pathways and to compare the consequences of the various radiation exposure paths to living organisms.     

Surface green function matching approach to the surface dynamics of ionic crystals: I. Equivalence with the invariant green function method

The surface Green function matching (SGFM) method is shown to be equivalent to the Green function method in its translationally and rotationally invariant formulation (IGF). Such equivalence between matching and invariance conditions makes the SGFM method easily applicable to the surface dynamics of ionic crystals, due to the existing possibility of deriving an effective short-range perturbation from the invariance conditions. An application to the inelastic scattering of He from LiF(001) in the eikonal approximation is presented.     

Some polishing experiments on copper in a hyperbolic cell

Some polishing experiments have been carried out on copper anodes in a hyperbolic cell designed by Gilmont and Walton, using orthophosphoric acid as the electrolyte. The results obtained have been compared to those obtained in similar experiments in a Hull cell. It has been found that very similar bands of different reflectivity and polishes are found to form in both the cells. These bands shift with time and a study of such displacements has been made. The results are briefly discussed.     

Performing Flexible Control on Low-Cost Microcontrollers Using a Minimal Real-Time Kernel

In recent years, approaches to control performance and resource optimization for embedded control systems have been receiving increased attention. Most of them focus on theory, whereas practical aspects are omitted. Theoretical advances demand flexible real-time kernel support for multitasking and preemption, thus requiring more sophisticated and expensive software/hardware solutions. On the other hand, embedded control systems often have cost constraints related with mass production and strong industrial competition, thus demanding low-cost solutions. In this paper, it is shown that these conflicting demands can be softened and that a compromise solution can be reached. We advocate that recent research results on optimal resource management for control tasks can be implemented on simple multitasking preemptive real-time kernels targeting low-cost microprocessors, which can be easily built in-house and tailored to actual application needs. The experimental evaluation shows that significant control performance improvement can be achieved without increasing hardware costs.     

Optimisation of a key cross-coupling reaction towards the synthesis of a promising antileishmanial compound

During the course of a research program aimed at identifying novel antileishmanial compounds, a multi-gram synthesis of N-(trans-4-((4-methoxy-3-((R)-3-methylmorpholino)-1H-pyrazolo[3,4-d]pyrimidin-6-yl)amino)cyclohexyl)-2-methylpropane-1-sulfonamide ((R)-1) was required. This letter describes optimisation of the reaction conditions and protecting group strategy for a key Buchwald-Hartwig coupling, delivering the required quantities of (R)-1, as well as further compounds in the series.     

Full configuration interaction calculation of the low lying valence and Rydberg states of BeH

The all-electron full configuration interaction (FCI) vertical excitation energies for some low lying valence and Rydberg excited states of BeH are presented in this article. A basis set of valence atomic natural orbitals has been augmented with a series of Rydberg orbitals that have been generated as centered onto the Be atom. The resulting basis set can be described as 4s2p1d/2s1p (Be/H) + 4s4p3d. It allows to calculate Rydberg states up to n= {3,4,5} of the s, p, and d series of Rydberg states. The FCI vertical ionization potential for the same basis set and geometry amounts to 8.298 eV. Other properties such as FCI electric dipole and quadrupole moments and FCI transition dipole and quadrupole moments have also been calculated. The results provide a set of benchmark values for energies, wave functions, properties, and transition properties for the five electron BeH molecule. Most of the states have large multiconfigurational character in spite of their essentially single excited nature and a number of them present an important Rydberg-valence mixing that is achieved through the mixed nature of the particle MO of the single excitations.     

Full configuration interaction calculation of BeH adiabatic states

An all-electron full configuration interaction (FCI) calculation of the adiabatic potential energy curves of some of the lower states of BeH molecule is presented. A moderately large ANO basis set of atomic natural orbitals (ANO) augmented with Rydberg functions has been used in order to describe the valence and Rydberg states and their interactions. The Rydberg set of ANOs has been placed on the Be at all bond distances. So, the basis set can be described as 4s3p2d1f3s2p1d(BeH)+4s4p2d(Be). The dipole moments of several states and transition dipole strengths from the ground state are also reported as a function of the R(Be-H) distance. The position and the number of states involved in several avoided crossings present in this system have been discussed. Spectroscopic parameters have been calculated from a number of the vibrational states that result from the adiabatic curves except for some states in which this would be completely nonsense, as it is the case for the very distorted curves of the 3s and 3p (2)Sigma(+) states or the double-well potential of the 4p (2)Pi state. The so-called "D complex" at 54 050 cm(-1) (185.0 nm) is resolved into the three 3d substates ((2)Sigma(+),(2)Pi,(2)Delta). A diexcited valence state is calculated as the lowest state of (2)Sigma(-) symmetry and its spectroscopic parameters are reported, as well as those of the 2 (2)Delta (4d) state The adiabatic curve of the 4 (2)Sigma(+) state shows a swallow well at large distances (around 4.1 A) as a result of an avoided crossing with the 3 (2)Sigma(+) state. The probability that some vibrational levels of this well could be populated is discussed within an approached Landau-Zerner model and is found to be high. No evidence is found of the E(4ssigma) (2)Sigma(+) state in the region of the "D complex". Instead, the spectroscopic properties obtained from the (4ssigma) 6 (2)Sigma(+) adiabatic curve of the present work seem to agree with those of the experimental F(4psigma) (2)Sigma(+) state. The FCI calculations provide benchmark results for other correlation models for the open-shell BeH system and evidence both the limitations and capabilities of the basis set.