919 research outputs found
Optimal performance of equilibrium parametric pumps
An examination of the conditions required to obtain the optimal performance of semicontinuous and continuous parametric pumps, defined by the achieving of the maximum possible solute free product for a given column height, was undertaken. The model system sodium nitrate ? water on an ion retardation resin adsorbate was employed. Equations defining maximum values of certain important parameters such as the bottom product flow rate and reservoir displacement rate were developed by extending previous theories of parametric pumping. Experimental runs were carried out using parameters whose values were both less than and greater than the maximum values predicted for optimal performance. It was found that for pumps operating with parameter values less than the limiting maximum values, complete removal of solute from the bottom of the column was obtained. Furthermore, for those pumps for which the parameter values were greater than the predicted maximum quantities only partial removal of solute was observed. The experimental results agreed quantitatively as well as qualitatively with the theory for almost all runs
The complementary role of imaging and tumor biomarkers in gynecological cancers: an update of the literature
Gynecological tumors, including endometrial, cervical and ovarian cancer, have increased in incidence over
time. The widespread introduction of screening programs and advances in diagnostic imaging methods has lead to a
progressive increase in gynecological cancer detection. Accurate diagnosis and proper monitoring of disease remain
the primary target for a successful treatment. In the last years, knowledge about cancer biomarkers has considerably
increased providing great opportunities for improving cancer detection and treatment. In addition, in the last few years
there has been an important development of imaging techniques. Nowadays, a multimodal approach including the
evaluation of serum tumor biomarkers combined with imaging techniques, seems to be the best strategy for assessing
tumor presence, spread, recurrence, and/or the response to treatment in female cancer patients In this review we provide
an overview of the application of biomarkers combined with novel imaging methods and highlight their roles in female
cancer diagnosis and follow-up
Mechanisms producing fissionlike binary fragments in heavy collisions
The mixing of the quasifission component to the fissionlike cross section
causes ambiguity in the quantitative estimation of the complete fusion cross
section from the observed angular and mass distributions of the binary
products. We show that the partial cross section of quasifission component of
binary fragments covers the whole range of the angular momentum values leading
to capture. The calculated angular momentum distributions for the compound
nucleus and dinuclear system going to quasifission may overlap: competition
between complete fusion and quasifission takes place at all values of initial
orbital angular momentum. Quasifission components formed at large angular
momentum of the dinuclear system can show isotropic angular distribution and
their mass distribution can be in mass symmetric region similar to the
characteristics of fusion-fission components. As result the unintentional
inclusion of the quasifission contribution into the fusion-fission fragment
yields can lead to overestimation of the probability of the compound nucleus
formation.Comment: 15 pages, 6 figures, International Conference on Nuclear Reactions on
Nucleons and Nuclei, Messina, Italy, October 5-9, 200
Suppression of threading defects formation during Sb-assisted metamorphic buffer growth in InAs/InGaAs/InP structure
A virtual substrate for high quality InAs epitaxial layer has been attained
via metalorganic vapor-phase epitaxy growth of Sb-assisted InxGa1-xAs
metamorphic buffers, following a convex compositional continuous gradient of
the In content from x = 53 % to 100 %. The use of trimethylantimony (or its
decomposition products) as a surfactant has been found to crucially enable the
control over the defect formation during the relaxation process. Moreover, an
investigation of the wafer offcut-dependence of the defect formation and
surface morphology has enabled the achievement of a reliably uniform growth on
crystals with offcut towards the [111]B direction
Quasifission and fusion-fission in massive nuclei reactions. Comparison of reactions leading to the Z=120 element
The yields of evaporation residues, fusion-fission and quasifission fragments
in the Ca+Sm and O+W reactions are analyzed
in the framework of the combined theoretical method based on the dinuclear
system concept and advanced statistical model. The measured yields of
evaporation residues for the Ca+Sm reaction can be well
reproduced. The measured yields of fission fragments are decomposed into
contributions coming from fusion-fission, quasifission, and fast-fission. The
decrease in the measured yield of quasifission fragments in
Ca+Sm at the large collision energies and the lack of
quasifission fragments in the Ca+Sm reaction are explained by
the overlap in mass-angle distributions of the quasifission and fusion-fission
fragments. The investigation of the optimal conditions for the synthesis of the
new element =120 (=302) show that the Cr+Cm reaction is
preferable in comparison with the Fe+Pu and Ni+U
reactions because the excitation function of the evaporation residues of the
former reaction is some orders of magnitude larger than that for the last two
reactions.Comment: 27 pages, 12 figures, submitted to Phys. Rev.
Unusual nanostructures of "lattice matched" InP on AlInAs
We show that the morphology of the initial monolayers of InP on
Al0.48In0.52As grown by metalorganic vapor-phase epitaxy does not follow the
expected layer-by-layer growth mode of lattice-matched systems, but instead
develops a number of low-dimensional structures, e.g., quantum dots and wires.
We discuss how the macroscopically strain-free heteroepitaxy might be strongly
affected by local phase separation/alloying-induced strain and that the
preferred aggregation of adatom species on the substrate surface and reduced
wettability of InP on AlInAs surfaces might be the cause of the unusual (step)
organization and morpholog
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