SSR™ Semi-Solid Rheocasting

Il processo IdraPrince SSR™ (Semi-Solid Rheocasting) è una nuova tecnologia sviluppata da Idraprofondamente diversa da tutti gli altri processi sviluppati precedentemente nell’area delle leghe allostato semi-solido. A differenza delle altre tecnologie il vantaggio competitivo dell’SSR™ è di utilizzareleghe commerciali secondarie quali EN 46000, senza aggravio di costi della materia prima permigliorare la qualità dei getti utilizzando macchine di pressofusione tradizionali.In questo modo la tecnologia SSR™ diventa giustificata non solo per particolari ad alta integrità prodottiin leghe primarie ma il risparmio dovuto alla riduzione del tempo ciclo, alla maggior durata degli stampie all’eliminazione totale dell’impregnazione o quanto meno una sua drastica riduzione come di certe fasidella lavorazione meccanica, giustifica economicamente l’uso dell’SSR™ con un tempo di ritornodell’investimento, in qualche caso inferiore ai 12 mesi

Commercial development of the semi-solid rheocasting (ssrtm) process

Rheocasting processes create non-dendritic, equiaxed microstructure suitable for semi-solid forming directly from liquid aluminum alloy. A new rheocasting technology that efficiently creates non-dendritic material was developed at the Massachusetts Institute of Technology in 2000 and discussed at the previous NADCA Congress in Cincinnati in 2001. In early 2002, Idra Casting Machines acquired the exclusive license from M.I.T. to develop and sell casting equipment utilizing the technology.Now known as Semi-Solid Rheocasting (SSRTM), the process has undergone development from the laboratory to a commercial machine. Designed as a retrofit for die casting machines, the rheocast machine allows die casters to not only increase part quality and make safety critical castings, but also to decrease cycle time and increase tool life. In this paper, the SSRTM station will be described in detail, and advantages of the process will be discussed

Uniqueness of the potential function for the vectorial Sturm-Liouville equation on a finite interval

[[abstract]]In this paper, the vectorial Sturm-Liouville operator L Q =−d 2 dx 2 +Q(x) is considered, where Q(x) is an integrable m×m matrix-valued function defined on the interval [0,π] . The authors prove that m 2 +1 characteristic functions can determine the potential function of a vectorial Sturm-Liouville operator uniquely. In particular, if Q(x) is real symmetric, then m(m+1) 2 +1 characteristic functions can determine the potential function uniquely. Moreover, if only the spectral data of self-adjoint problems are considered, then m 2 +1 spectral data can determine Q(x) uniquely.[[notice]]補正完畢[[incitationindex]]SCI[[cooperationtype]]國外[[booktype]]電子

Inverse spectral problems for Sturm-Liouville operators with singular potentials

The inverse spectral problem is solved for the class of Sturm-Liouville operators with singular real-valued potentials from the space $W^{-1}_2(0,1)$. The potential is recovered via the eigenvalues and the corresponding norming constants. The reconstruction algorithm is presented and its stability proved. Also, the set of all possible spectral data is explicitly described and the isospectral sets are characterized.Comment: Submitted to Inverse Problem

Inverse spectral problems for Sturm--Liouville operators with matrix-valued potentials

We give a complete description of the set of spectral data (eigenvalues and specially introduced norming constants) for Sturm--Liouville operators on the interval $[0,1]$ with matrix-valued potentials in the Sobolev space $W_2^{-1}$ and suggest an algorithm reconstructing the potential from the spectral data that is based on Krein's accelerant method.Comment: 39 pages, uses iopart.cls, iopams.sty and setstack.sty by IO

Structure of the icosahedral Ti-Zr-Ni quasicrystal

The atomic structure of the icosahedral Ti-Zr-Ni quasicrystal is determined by invoking similarities to periodic crystalline phases, diffraction data and the results from ab initio calculations. The structure is modeled by decorations of the canonical cell tiling geometry. The initial decoration model is based on the structure of the Frank-Kasper phase W-TiZrNi, the 1/1 approximant structure of the quasicrystal. The decoration model is optimized using a new method of structural analysis combining a least-squares refinement of diffraction data with results from ab initio calculations. The resulting structural model of icosahedral Ti-Zr-Ni is interpreted as a simple decoration rule and structural details are discussed.Comment: 12 pages, 8 figure

Flavor-Specific Inclusive B Decays to Charm

We have measured the branching fractions for B -> D_bar X, B -> D X, and B -> D_bar X \ell^+ \nu, where ``B'' is an average over B^0 and B^+, ``D'' is a sum over D^0 and D^+, and``D_bar'' is a sum over D^0_bar and D^-. From these results and some previously measured branching fractions, we obtain Br(b -> c c_bar s) = (21.9 $\pm$ 3.7)%, Br(b -> s g) K^- \pi^+) = (3.69 $\pm$ 0.20)%. Implications for the ``B semileptonic decay problem'' (measured branching fraction being below theoretical expectations) are discussed. The increase in the value of Br(b -> c c_bar s) due to $B -> D X$ eliminates 40% of the discrepancy.Comment: 12 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN

Measurement of Br(D0→K−π+)Br(D^{0}\to K^{-}\pi^{+}) using Partila Reconstruction of Bˉ→D∗+Xℓ−νˉ\bar{B}\to D^{*+}X\ell^{-}\bar{\nu}

We present a measurement of the absolute branching fraction for $D^0 -> K^- pi^+$ using the reconstruction of the decay chain $Bbar -> D^{*+} X l^- nubar$, $D^{*+} -> D^0 pi^+$ where only the lepton and the low-momentum pion from the $D^{*+}$ are detected. With data collected by the CLEO II detector at the Cornell Electron Storage Ring, we have determined $Br(D^0 -> K^- pi^+)= [3.81 +- 0.15(stat.) +- 0.16(syst.)]$.Comment: 10 page postscript file, postscript file also available through http://w4.lns.cornell.edu/public/CLN