A self-consistent model calculation of the electronic structure of ordered,disordered and hydrogenated Pd3Fe

We study, within the Bethe lattice approximation, the electronic structure of the ordered, disordered and hydrogenated intermetallic Pd₃Fe. We employ a simple one-orbital per site model hamiltonian, which includes a Hubbard-like Coulomb interaction term. This is treated in the Hartree-Fock approximation. We present results for the number of electrons, magnetic moments, and density of states at the Fermi level. Good agreement with available experimental data is obtained.     

Ascorbic acid in cosmetic formulations: Stability,in vitro release,and permeation using a rapid,inexpensive, and simple method

Ascorbic acid (AA) is involved in important metabolic processes in the human body. However, its chemical instability requires the assessment of products containing AA. The aim of this study was to develop systems that improve AA stability and to evaluate its release profile, permeation, and skin retention in vitro. For this purpose, we prepared binary systems consisting of propylene glycol and water, microemulsions, liquid crystalline systems, and an emulsion. The AA content in these systems was evaluated over time by measuring the inhibition of 1,1-diphenyl-2-picrylhydrazyl (DPPH). Our results demonstrated that the binary systems and molecular aggregates were less stable and effective than the emulsion. Thus, in vitro AA release, skin permeation, and retention were evaluated using the emulsion. Our results indicate that AA exhibits low release and permeation levels and a high retention rate in the skin, characteristics desirable in cosmetic products.     

4'-Acetamidochalcone derivatives as potential antinociceptive agents

Nine acetamidochalcones were synthesized and evaluated as antinociceptive agents using the mice writhing test. Given intraperitoneally all the compounds were more effective than the two reference analgesic drugs (acetylsalicylic acid and acetaminophen) used for comparison. N-{4-[(2E)-3-(4-nitrophenyl)prop-2-enoyl]phenyl}acetamide (6) was the most effective compound and was therefore selected for more detailed studies. It caused dose-related inhibition in the writhing test, being about 32 to 34-fold more potent than the standard drugs. It was also effective in the second phase of the formalin test and the capsaicin test. These acetamidochalcones, especially compound 6, might be further used as models to obtain new and more potent analgesic drugs.     

STUDY ON TARGET RESIDUES FROM THE INTERACTION OF COPPER WITH 44MeV/A12C IONS

Cross sections and average forward ranges were determined for 35 target residues from the interaction of copper with 44MeV/A¹²C ions with nuclear chemistry techniques.From these data the isobaric yield distribution,the mass yield distribution and the longitudinal momentum transfer were obtained.The mass yield distribution and the isobaric yield distribution are in good agreement with those calculated from a modified statistical model and corresponding Monte Carlo technique.     

STUDY OF πNN VERTEX FROM HADRON AND QUARK POINT OF VIEW

we have identified the first-order mixing amplitude of πNN process described by the hadron model with the second-order mixing amplitude of the same process described by the quark model.Then the expression for the coupling constant f_π of the πNN vertex with different quark wave functions and gluon propagators in different approximations has been derived. The calculation results of f_π have been compared with experimental data.     

Nuclear Liquid-Gas Phase Transition Shown in Multifragment ation

The Incomplete-Fusion-nagmentation Model has been used to reproduce nicely the experimental evidence of liquid-gas phase transition probed in the reaction of Au + Au at 600A MeV. The analysis of the relative yields of decay modes for the projectile remnant as a function of bound> shows clearly the competition and transformation processes of various decay modes of projectile remnant with decreasing of bound>. The agreement between theoretical and experimental results for the anaJysis of relative yield of decay modes indicates that the experimental evidence of liquid-gas phase transition is composed of the decay mode transformations.     

Strangeness production in pA and AA collisions at 158 A GeV

LUCIAE, a hadronic and string cascade model and its corresponding event generator are used to analyse strangeness production singly and multiply in p-Pb and Pb-Pb collisions at 158 A GeV. Spectra of multiplicity and transverse mass for single (Λ, Λ) and multiple (Ξ-, Ξ-, Ω-, Ω-) strangeness are given. In LUCIAE model it suggests a physical mechanism, i.e. the dependence of the strange quark suppression factor on incident energy, projectile mass and centrality of colliding system might result in increase of yield of strange particles with increasing the above three parameters. Calculations from the model reconstruct well the WA97 experimental data: increase of yield of strange particles with increasing centrality and increase of strangeness enhancement with increasing number of strange quarks, in relativistic nucleus-nucleus collisions.     

Justification of the Kirchhoff hypotheses and error estimation for two-dimensional models of anisotropic and inhomogeneous plates, including laminated plates

Asymptotic analysis of the problem describing deformation ofa thin cylindrical plate with clamped lateral side is performed.The problem is considered under the most general statement withthe plate being laminated and consisting of an arbitrary numberof nonhomogeneous and anisotropic (21 elastic moduli) layers.Explicit integral representations of the differential operatorswhich form the two-dimensional model of the plate are derived.In the case when the elastic moduli of each of the layers areconstant, these integral representations turn into algebraicones. The asymptotic procedure is justified with the help ofa weighted inequality of Korn's type. The error estimates obtainedgive a rigorous mathematical proof of both of Kirchhoff's hypotheses(kinematic and static) and shed light on the well-known intrinsicinconsistency of two of the hypotheses.     

Kinetic study of non-reactive iron removal from iron-gall inks

The removal of non-reactive iron for different combinations of Fe²⁺ and tannic acid in irongall inks, via calcium phytate solutions, was studied. In parallel, the non-reactive iron removal kinetics was investigated using the pseudo first-order and second-order kinetic models. The results showed that the use of a dilute solution of calcium phytate to wash the impregnated paper strips removed the non-reactive iron from iron-gall inks in approximately 15 min in stoichiometric and non-stoichiometric combinations of iron and tannic acid. A second washing of the paper strips after an accelerated ageing, showed a distinct kinetic behaviour, with iron removal taking place simultaneously but apparently via a different mechanism. The use of a reference calcium phytate solution exhibited the same behaviour, suggesting that the use of dilute solutions as iron removal agents would represent less damage to historical documents. The results of kinetic modelling showed that all the combinations of Fe²⁺ and tannic acid used fitted the pseudo first-order kinetic model, when dilute and reference phytate solutions were tested as iron-desorbing agents.     

Spectroscopic characterization and crystal structure of cis-Bis(N-(2-benzoyl)-N′,N′-diphenylthioureato-k 2O,S)nickel(II)

The title compound [Ni(C₂₀H₁₅N₂OS)₂] is prepared by the reaction of metal acetate with the corresponding acylthiourea derivative. The complex is characterized by elemental analysis, IR, ¹H and ¹³C NMR, and its structure is determined by single crystal X-ray diffraction. The Ni(II) ion is coordinated by the S and O atoms of two N-benzoyl-N??,N??-diphenylthiourea ligands in a slightly distorted square-planar coordination geometry. The two O and two S atoms are mutually cis to each other. The substance crystallizes triclinic (P-1 space group) with cell dimensions a = 10.7262(9) ?, b = 12.938(3) ?, c = 14.2085(12) ?, ?? = 74.650(4)°, ?? = 78.398(4)°, ?? = 68.200(5)°, and two formula units in the unit cell. The structure is very close to the related N-(2-furoyl) Ni complex reported previously.