Pairing gaps from nuclear mean-field models

We discuss the pairing gap, a measure for nuclear pairing correlations, in chains of spherical, semi-magic nuclei in the framework of self-consistent nuclear mean-field models. The equations for the conventional BCS model and the approximate projection-before-variation Lipkin-Nogami method are formulated in terms of local density functionals for the effective interaction. We calculate the Lipkin-Nogami corrections of both the mean-field energy and the pairing energy. Various definitions of the pairing gap are discussed as three-point, four-point and five-point mass-difference formulae, averaged matrix elements of the pairing potential, and single-quasiparticle energies. Experimental values for the pairing gap are compared with calculations employing both a delta pairing force and a density-dependent delta interaction in the BCS and Lipkin-Nogami model. Odd-mass nuclei are calculated in the spherical blocking approximation which neglects part of the the core polarization in the odd nucleus. We find that the five-point mass difference formula gives a very robust description of the odd-even staggering, other approximations for the gap may differ from that up to 30% for certain nuclei.Comment: 17 pages, 8 figures. Accepted for publication in EPJ

Consequences of the center-of-mass correction in nuclear mean-field models

We study the influence of the scheme for the correction for spurious center-of-mass motion on the fit of effective interactions for self-consistent nuclear mean-field calculations. We find that interactions with very simple center-of-mass correction have significantly larger surface coefficients than interactions for which the center-of-mass correction was calculated for the actual many-body state during the fit. The reason for that is that the effective interaction has to counteract the wrong trends with nucleon number of all simplified schemes for center-of-mass correction which puts a wrong trend with mass number into the effective interaction itself. The effect becomes clearly visible when looking at the deformation energy of largely deformed systems, e.g. superdeformed states or fission barriers of heavy nuclei.Comment: 12 pages LATeX, needs EPJ style files, 5 eps figures, accepted for publication in Eur. Phys. J.

The reaction of selected southern Ontario newspapers to the entrance of Newfoundland into confederation, 1945-1949.

In this thesis, the viewpoint of the southwestern Ontario press via three representative newspapers will be looked at from December 11, 1945 (the day the United Kingdom\u27s Prime Minister Clement Attlee announced the calling of a National Convention in Newfoundland to decide that country\u27s future government) until the first week in April 1949 (when Newfoundland\u27s provincial government behan to function after confederation with Canada) in order to trace their coverage of these developments. The three papers chosen were The London Evening Free Press, The Windsor Daily Star, and The (Toronto) Globe and Mall. The major objective of this study will be to determine the attitude of the south-western Ontario papers towards Newfoundland and confederation

Optimum Slot Weld Width for Cold-Formed Steel

Slot welds can be used for connections in cold-formed steel (CFS) structures. However, structural engineers will find AISI S100, “North American Specification for the Design of Cold-Formed Steel Structural Members” (AISI 2016) - which can be used for guidance in calculating structural capacity of many welds types - silent on this specific application. Research at the University of Colorado Denver has been directed toward determination of the strength of slot welds in sheet steel. A comprehensive series of tests were performed to determine structural capacity and ductility of various slot weld widths using a metal inert gas (MIG) welding process. A slot weld connection between two pieces of sheet steel was designed, one with punched slots of various widths, and the other a blank piece to receive the weld. Weldability problems associated with slot welds of various widths on galvanized sheet steel were encountered. The testing program to investigate slot widths to address these concerns is reported upon. A program of monotonic tension tests was conducted. This testing program built on 1979 research by Pekoz and McGuire at Cornell University for fillet welds on lap joint specimens. While AISI is silent on slot weld design criteria, the authors found certain slot widths were more advantageous than others

Identification of Unknown Contaminants in Water Samples from ISS Employing Liquid Chromatography/Mass Spectrometry/Mass Spectrometry

Mass Spectrometry/Mass Spectrometry (MS/MS) is a powerful technique for identifying unknown organic compounds. For non-volatile or thermally unstable unknowns dissolved in liquids, liquid chromatography/mass spectrometry/mass spectrometry (LC/MS/MS) is often the variety of MS/MS used for the identification. One type of LC/MS/MS that is rapidly becoming popular is time-of-flight (TOF) mass spectrometry. This technique is now in use at the Johnson Space Center for identification of unknown nonvolatile organics in water samples from the space program. An example of the successful identification of one unknown is reviewed in detail in this paper. The advantages of time-of-flight instrumentation are demonstrated through this example as well as the strategy employed in using time-of-flight data to identify unknowns

Seasonal Variation in Carcinops pumilio (Coleoptera: Histeridae) Dispersal and Potential for Suppression of Dispersal Behavior

Seasonal dispersal of Carcinops pumilio (Erichson) was evaluated using two trapping methods-a black-light pitfall trap and a mesh-bottomed trap placed on poultry manure. The black-light trap collected larger numbers than the mesh-bottomed trap from March through June. The mesh-bottomed trap gathered larger numbers of beetles from June through August and numbers were less variable throughout the year. Often, when very low numbers of beetles were recovered from manure cores, large numbers of beetles could be collected with the black-light trap suggesting that beetle density may not be an important factor in dispersal behavior. The greatest dispersal in the dispersal arenas (≈90%) occurred using beetles collected by both trap types in June 2000. Beginning in March and ending in August, a cyclic rise and then fall pattern in both laboratory dispersal and beetle collections was observed. Trap collection patterns were similar in both years of the study. In January and March, we were unable to prevent dispersal behavior of beetles captured in black-light traps. However, in May, after beetles had been in a dispersal phase for several months, we were able to suppress dispersal. In contrast, dispersal behavior among beetles captured with the mesh-bottomed trap did not change following the photoperiod-altered exposur

An HFB scheme in natural orbitals

We present a formulation of the Hartree-Fock-Bogoliubov (HFB) equations which solves the problem directly in the basis of natural orbitals. This provides a very efficient scheme which is particularly suited for large scale calculations on coordinate-space grids.Comment: 5 pages RevTeX, (Postscript-file also available at http://www.th.physik.uni-frankfurt.de/~bender/nucl_struct_publications.html or at ftp://th.physik.uni-frankfurt.de/pub/bender ), accepted for publication in Z. Phys.

Emergency Physicians Are Able to Detect Right Ventricular Dilation With Good Agreement Compared to Cardiology

Objective Focused cardiac ultrasound (FOCUS) is a useful tool in evaluating patients presenting to the emergency department (ED) with acute dyspnea. Prior work has shown that right ventricular (RV) dilation is associated with repeat hospitalizations and shorter life expectancy. Traditionally, RV assessment has been evaluated by cardiologist-interpreted comprehensive echocardiography. The primary goal of this study was to determine the inter-rater reliability between emergency physicians (EPs) and a cardiologist for determining RV dilation on FOCUS performed on ED patients with acute dyspnea. Methods This was a prospective, observational study at two urban academic EDs; patients were enrolled if they had acute dyspnea and a computed tomographic pulmonary angiogram without acute disease. All patients had an EP-performed FOCUS to assess for RV dilation. RV dilation was defined as an RV to left ventricular ratio greater than 1. FOCUS interpretations were compared to a blinded cardiologist FOCUS interpretation using agreement and kappa statistics. Results Of 84 FOCUS examinations performed on 83 patients, 17% had RV dilation. Agreement and kappa, for EP-performed FOCUS for RV dilation were 89% (95% confidence interval [CI] 80–95%) and 0.68 (95% CI 0.48–0.88), respectively. Conclusions Emergency physician sonographers are able to detect RV dilation with good agreement when compared to cardiology. These results support the wider use of EP-performed FOCUS to evaluate for RV dilation in ED patients with dyspnea

Utilização do farelo de canola em rações para frangos de corte.

O que e farelo de canola?; O valor nutritivo do farelo de canola; Utilização do farelo de canola; Cuidados com o uso do farelo de canola.bitstream/item/59455/1/CUsersPiazzonDocuments4.pd

Ion-Exclusion Chromatography for Analyzing Organics in Water

A liquid-chromatography technique has been developed for use in the quantitative analysis of urea (and of other nonvolatile organic compounds typically found with urea) dissolved in water. The technique involves the use of a column that contains an ion-exclusion resin; heretofore, this column has been sold for use in analyzing monosaccharides and food softeners, but not for analyzing water supplies. The prior technique commonly used to analyze water for urea content has been one of high-performance liquid chromatography (HPLC), with reliance on hydrophobic interactions between analytes in a water sample and long-chain alkyl groups bonded to an HPLC column. The prior technique has proven inadequate because of a strong tendency toward co-elution of urea with other compounds. Co-elution often causes the urea and other compounds to be crowded into a narrow region of the chromatogram (see left part of figure), thereby giving rise to low chromatographic resolution and misidentification of compounds. It is possible to quantitate urea or another analyte via ultraviolet- and visible-light absorbance measurements, but in order to perform such measurements, it is necessary to dilute the sample, causing a significant loss of sensitivity. The ion-exclusion resin used in the improved technique is sulfonated polystyrene in the calcium form. Whereas the alkyl-chain column used in the prior technique separates compounds on the basis of polarity only, the ion-exclusion-resin column used in the improved technique separates compounds on the basis of both molecular size and electric charge. As a result, the degree of separation is increased: instead of being crowded together into a single chromatographic peak only about 1 to 2 minutes wide as in the prior technique, the chromatographic peaks of different compounds are now separated from each other and spread out over a range about 33 minutes wide (see right part of figure), and the urea peak can readily be distinguished from the other peaks. Although the analysis takes more time in the improved technique, this disadvantage is offset by two important advantages: Sensitivity is increased. The minimum concentration of urea that can be measured is reduced (to between 1/5 and 1/3 of that of the prior technique) because it is not necessary to dilute the sample. The separation of peaks facilitates the identification and quantitation of the various compounds. The resolution of the compounds other than urea makes it possible to identify those compounds by use of mass spectrometry