Influence of probability distribution in measurement uncertainty of plane-strain fracture toughness test

Accreditation and Quality Assurance - The evaluation of measurement uncertainty by testing laboratories has a direct impact on the interpretation of the results. In several cases, it is recommended...     

A discrete geometric approach to solving time independent Schrödinger equation

The time independent Schrödinger equation stems from quantum theory axioms as a partial differential equation. This work aims at providing a novel discrete geometric formulation of this equation in terms of integral variables associated with precise geometric elements of a pair of three-dimensional interlocked grids, one of them based on tetrahedra. We will deduce, in a purely geometric way, a computationally efficient discrete counterpart of the time independent Schrödinger equation in terms of a standard symmetric eigenvalue problem. Moreover boundary and interface conditions together with non homogeneity and anisotropy of the media involved are accounted for in a straightforward manner.This approach yields to a sensible computational advantage with respect to the finite element method, where a generalized eigenvalue problem has to be solved instead. Such a modeling tool can be used for analyzing a number of quantum phenomena in modern nano-structured devices, where the accounting of the real 3D geometry is a crucial issue.     

Gold(III)–pyrrolidinedithiocarbamato Derivatives as Antineoplastic Agents

Transition metals offer many possibilities in developing potent chemotherapeutic agents. They are endowed with a variety of oxidation states, allowing for the selection of their coordination numbers and geometries via the choice of proper ligands, leading to the tuning of their final biological properties. We report here on the synthesis, physico-chemical characterization, and solution behavior of two gold(III) pyrrolidinedithiocarbamates (PDT), namely [Au^IIIBr₂(PDT)] and [Au^IIICl₂(PDT)]. We found that the bromide derivative was more effective than the chloride one in inducing cell death for several cancer cell lines. [Au^IIIBr₂(PDT)] elicited oxidative stress with effects on the permeability transition pore, a mitochondrial channel whose opening leads to cell death. More efficient antineoplastic strategies are required for the widespread burden that is cancer. In line with this, our results indicate that [Au^IIIBr₂(PDT)] is a promising antineoplastic agent that targets cellular components with crucial functions for the survival of tumor cells.     

Inertial circulation of the western Mediterranean sea

Summary The essential features of the steady circulation of the western Mediterranean are reproduced by means of a vertically integrated model. In the framework of barotropic theory, it is shown how the effects of the geometry of the basin, including the islands, of the variable bottom topography and of the forcing of the flow at the Gibraltar Strait concur in determining the circulation pattern. Some observed features in particular regions, such as the Ligurian Sea, which are not reproduced by the model, indicate where baroclinic and/or wind-driven dynamics are likely to dominate. Paper presented at the 1^o Congresso del Gruppo Nazionale per la Fisica dell'Atmosfera e dell'Oceano, June 19–22, 1984, Rome.     

A fine-mesh objective analysis scheme in isentropic co-ordinates

Summary This paper deals with the problem of meteorological data analysis on the mesoscale, particularly in mountainous regions. A finemesh objective analysis scheme in isentropic co-ordinates apt to diagnose atmospheric structures on the scale of 100 km is presented and the results of its application to the high-resolution ALPEX data are shown as an example. The choice of isentropic co-ordinates, together with the extensive use of measurements at ground level and the application of accurate reduction techniques prove adequate to provide the desired resolution and smoothness even in the presence of rough and steep mountains such as the Alps. Paper presented at the 1° Congresso del Gruppo Nazionale per la Fisica dell'Atmosfera e dell'Oceano, June 19–22, 1984, Rome.     

The Exact Solution for the Dirac Equation with the Cornell Potential

An analytical solution of the Dirac equation with a Cornell potential, with identical scalar and vectorial parts, is presented. The solution is obtained by using the linear potential solution, related to Airy functions, multiplied by another function to be determined. The energy levels are obtained and we notice that they obey a band structure.     

Proficiency testing in food microbiology “Aqua”: enumeration of Staphylococcus aureus

In 1999 the Food Microbiology laboratory of the Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe) started an interlaboratory comparison program for food microbiological tests, known as “Aqua, interlaboratory comparisons for quality assurance”. Aqua produces the test samples, applies statistical methods to estimate homogeneity and stability, processes and evaluates the results. The proficiency testing results allow to evaluate the performance of the laboratories, to identify possible differences and non-conformity, to demonstrate the competence and the quality of results, in order to take suitable corrective and/or preventive action after the individuation of the causes. Moreover, elaborating the results of several proficiency testing by using the control chart method, it is possible to evaluate the trend of the laboratory and to verify that the results are in statistical quality control.     

Multiparticle production in proton-nucleus collisions at 360 GeV/c using the European Hybrid spectrometer

360 GeV/c proton interactions with aluminium (Al) and gold (Au) targets are studied using the European Hybrid Spectrometer (EHS) equipped with the Rapid Cycling Bubble Chamber (RCBC). Multiplicities, rapidity distributions and correlations between leading and other produced particles are presented and compared with Monte Carlo calculations based on the multi-chain and Lund models.     

Cross sections and multiplicity distributions forK + p interactions at 70 GeV/c

Cross sections and charged multiplicity distributions forK ⁺ p interactions at 70 GeV/c are presented and compared withK ⁺ p data at other energies. Comparisons are also made with available π⁺ p,pp, andK ^? p data.