828 research outputs found
How BMW Is Defusing the Demographic Time Bomb
The article focuses on how the German car manufacturer, Bayerische Motoren Werke AG or BMW, is managing the effects of population aging on the industry. The redesign of BMW's factories to accommodate older workers and increase productivity is mentioned. Research on a pilot production line, which is based on a mix of employees who have an average age of 47 in the year 2017, is discussed. The roles of Peter Jürschick, Helmut Mauermann, Günther Stadler, and Kurt Dickert in the development of the pilot project are mentioned. The costs associated with an aging population are noted
The Conformal Willmore Functional: a Perturbative Approach
The conformal Willmore functional (which is conformal invariant in general
Riemannian manifold ) is studied with a perturbative method: the
Lyapunov-Schmidt reduction. Existence of critical points is shown in ambient
manifolds -where is a metric close
and asymptotic to the euclidean one. With the same technique a non existence
result is proved in general Riemannian manifolds of dimension three.Comment: 34 pages; Journal of Geometric Analysis, on line first 23 September
201
Molecular-orbital theory for the stopping power of atoms in the low velocity regime:the case of helium in alkali metals
A free-parameter linear-combination-of-atomic-orbitals approach is presented
for analyzing the stopping power of slow ions moving in a metal. The method is
applied to the case of He moving in alkali metals. Mean stopping powers for He
present a good agreement with local-density-approximation calculations. Our
results show important variations in the stopping power of channeled atoms with
respect to their mean values.Comment: LATEX, 3 PostScript Figures attached. Total size 0.54
Factorization and Nonfactorization in B Decays
Using NLL values for Wilson coefficients and including the contributions from
the penguin diagrams, we estimate the amount of nonfactorization in two-body
hadronic B decays. Also, we investigate the model dependence of the
nonfactorization parameters by performing the calculation using different
models for the form factors. The results support the universality of
nonfactorizable contributions in both Cabibbo-favored and Cabibbo-suppressed B
decays.Comment: 17 pages, 5 figures, revte
Theoretical study of incoherent phi photoproduction on a deuteron target
We study the photoproduction of phi mesons in deuteron, paying attention to
the modification of the cross section from bound protons to the free ones with
the aim of comparing with recent results at LEPS. For this purpose we take into
account Fermi motion in single scattering and rescattering of the phi to
account for phi absorption on a second nucleon as well as the rescattering of
the proton. We find that the contribution of the double scattering is much
smaller than the typical cross section of gamma p to phi p in free space, which
implies a very small screening of the phi production in deuteron. The
contribution from the proton rescattering, on the other hand, is found to be
not negligible compared to the cross section of gamma p to phi p in free space,
and leads to a moderate reduction of the phi photoproduction cross section on a
deuteron at forward angles if LEPS set up is taken into account. The Fermi
motion allows contribution of the single scattering in regions forbidden by
phase space in the free case. In particular, we find that for momentum
transferred squared close to the maximum value, the Fermi motion changes
drastically the shape of d sigma / dt, to the point that the ratio of this
cross section to the free one becomes very sensitive to the precise value of t
chosen, or the size of the bin used in an experimental analysis. Hence, this
particular region of t does not seem the most indicated to find effects of a
possible phi absorption in the deuteron. This reaction is studied theoretically
as a function of t and the effect of the experimental angular cuts at LEPS is
also discussed, providing guidelines for future experimental analyses of the
reaction.Comment: 17 pages, 16 figure
Spin pumping and magnetization dynamics in metallic multilayers
We study the magnetization dynamics in thin ferromagnetic films and small
ferromagnetic particles in contact with paramagnetic conductors. A moving
magnetization vector causes \textquotedblleft pumping\textquotedblright of
spins into adjacent nonmagnetic layers. This spin transfer affects the
magnetization dynamics similar to the Landau-Lifshitz-Gilbert phenomenology.
The additional Gilbert damping is significant for small ferromagnets, when the
nonmagnetic layers efficiently relax the injected spins, but the effect is
reduced when a spin accumulation build-up in the normal metal opposes the spin
pumping. The damping enhancement is governed by (and, in turn, can be used to
measure) the mixing conductance or spin-torque parameter of the
ferromagnet--normal-metal interface. Our theoretical findings are confirmed by
agreement with recent experiments in a variety of multilayer systems.Comment: 10 pages, 6 figure
Spectra of "Real-World" Graphs: Beyond the Semi-Circle Law
Many natural and social systems develop complex networks, that are usually
modelled as random graphs. The eigenvalue spectrum of these graphs provides
information about their structural properties. While the semi-circle law is
known to describe the spectral density of uncorrelated random graphs, much less
is known about the eigenvalues of real-world graphs, describing such complex
systems as the Internet, metabolic pathways, networks of power stations,
scientific collaborations or movie actors, which are inherently correlated and
usually very sparse. An important limitation in addressing the spectra of these
systems is that the numerical determination of the spectra for systems with
more than a few thousand nodes is prohibitively time and memory consuming.
Making use of recent advances in algorithms for spectral characterization, here
we develop new methods to determine the eigenvalues of networks comparable in
size to real systems, obtaining several surprising results on the spectra of
adjacency matrices corresponding to models of real-world graphs. We find that
when the number of links grows as the number of nodes, the spectral density of
uncorrelated random graphs does not converge to the semi-circle law.
Furthermore, the spectral densities of real-world graphs have specific features
depending on the details of the corresponding models. In particular, scale-free
graphs develop a triangle-like spectral density with a power law tail, while
small-world graphs have a complex spectral density function consisting of
several sharp peaks. These and further results indicate that the spectra of
correlated graphs represent a practical tool for graph classification and can
provide useful insight into the relevant structural properties of real
networks.Comment: 14 pages, 9 figures (corrected typos, added references) accepted for
Phys. Rev.
Nonresonant Three-body Decays of D and B Mesons
Nonresonant three-body decays of D and B mesons are studied. It is pointed
out that if heavy meson chiral perturbation theory (HMChPT) is applied to the
heavy-light strong and weak vertices and assumed to be valid over the whole
kinematic region, then the predicted decay rates for nonresonant charmless
3-body B decays will be too large and especially B^- --> pi^- K^+ K^- greatly
exceeds the current experimental limit. This can be understood as chiral
symmetry has been applied there twice beyond its region of validity. If HMChPT
is applied only to the strong vertex and the weak transition is accounted for
by the form factors, the dominant B^* pole contribution to the tree-dominated
direct three-body B decays will become small and the branching ratio will be of
order 10^{-6}. The decay modes B^- --> (K^- h^+ h^-)_{NR} and bar{B}^0 -->
(bar{K}^0 h^+h^-)_{NR} for h = pi, K are penguin dominated. We apply HMChPT in
two different cases to study the direct 3-body D decays and compare the results
with experiment. Theoretical uncertainties are discussed.Comment: 24 pages, 2 figures. New experimental results of direct 3-body D
decays as Reported at ICHEP2002 are included. To appear in Phys. Re
Quantitative Analysis Procedure for Building Materials in Historic Buildings by Applying Infrared Thermography
[EN] Historic buildings have a great cultural and architectural value. It is necessary to analyze their state of conservation, but sometimes it is difficult to perform laboratory tests without damaging this heritage. In the field of architecture, infrared thermography is usually used to provide descriptive information about the surface temperature of building materials. This current research presents a methodology widely applicable to historic buildings. As an example of application, the study is focused in the Seminary-School of Corpus Christi of Valencia (Spain), a very outstanding building from the 16th Century. This research presents an analytical study to be able to differentiate the temperature distribution of all pixels of a thermographic image. Thermal images are a matrix of data and their study helps us in decision-making based on objective data.Lerma Elvira, C.; Mas Tomas, MDLA.; Gil Benso, E.; Vercher Sanchis, JM.; Torner-Feltrer, MEM. (2018). Quantitative Analysis Procedure for Building Materials in Historic Buildings by Applying Infrared Thermography. Russian Journal of Nondestructive Testing. 54(8):601-609. https://doi.org/10.1134/S1061830918080065S601609548Avdelidis, N.P. and Moropoulou, A., Applications of infrared thermography for the investigation of historic structures, J. Cult. Heritage, 2004, no. 5, pp. 119–127. doi 10.1016/j.culher.2003.07.002Barreira, E. and Freitas, V., Evaluation of building materials using infrared thermography, Constr. Build. Mater., 2007, vol. 21, pp. 218–224. doi 10.1016/j.conbuildmat.2005.06.049Bauer, E., Pavón, E., Barreira, E., and Kraus, E., Analysis of building façade defects using infrared thermography: Laboratory studies, J. Build. Eng., 2016, no. 6, pp. 93–104. doi /doi 10.1016/j.jobe.2016.02.012Binda, L., Cardani, G., and Zanzi, L., Nondestructive testing evaluation of drying process in flooded full-scale masonry walls, J. Perform. Constr. Facil., 2010, pp. 473–483. doi 10.1061/(ASCE)CF.1943-5509.0000097Cañas, I., Martín, S., and González, I., Thermal-physical aspects of materials used for the construction of rural buildings in Soria (Spain), Construct. Build. Mater., 2005, vol. 19, pp. 197–211. doi 10.1016/j.conbuildmat. 2004.05.016Carlomagno, G.M., Maio, R., Fedi, M., Meola, C., Integration of infrared thermography and high-frequency electromagnetic methods in archaeological surveys, J. Geophys. Eng., 2011, vol. 8, pp. 93–105. doi 10.1088/1742-2132/8/3/S09Cerdeira, F., Vázquez, ME, Collado, J., and Granada, E., Applicability of infrared thermography to the study of the behavior of Stone panels as building envelopes, Energy Build., 2011, vol. 43, pp. 1845–1851. doi 10.1016/j.enbuild.2011.03.029EN 13187:1998. Thermal performance of buildings. Qualitative detection of thermal irregularities in building envelopes. Infrared method (ISO 6781:1983 modified).Galarza Tortajada, M., La tapia valenciana: una técnica constructiva poco conocida, Proc. First Natl. Congr. Construct. Hist., Madrid, 1996.Grinzato, E., Bison, P.G., and Marinetti, S., Monitoring of ancient buildings by the thermal method, J. Cult. Heritage, 2002, vol. 3, pp. 21–29. doi 10.1016/S1296-2074(02)01159-7Ibarra-Castanedo C., Sfarra, S., Ambrosini, D., Paoletti, D., Bendada, A, and Maldague, X., Diagnostics of panel paintings using holographic interferometry and pulsed thermography, Quant. Infrared Thermogr. J., 2010, vol. 7, no. 1. doi 10.3166/qirt.7.85-114Lagüela, S., Martínez, J., Armesto, J., and Arias, P., Energy efficiency studies through 3D laser scanning and thermographic technologies, Energy Build., 2011, vol. 43, pp. 1216–1221. doi 10.1016/j.enbuild.2010.12.031Lerma, C., Mas, Á., Gil, E., and Galiana, M., An analytical procedure for the study of the documented construction process of the Seminary-School of Corpus Christi in Valencia (Spain), Inf. Constr., 2014, vol. 66 (533), e007. doi 10.3989/ic.12.117Lerma, C., Mas, A., Gil, E., Vercher, J., and Penalver, M.J., Pathology of building materials in historic buildings. Relationship between laboratory testing and infrared thermography, Mater. Constr., 2014, vol. 64 (313), e009. doi 10.3989/mc.2013.06612Lerma, J.L., Cabrelles, M., and Portalés, C., Multitemporal thermal analysis to detect moisture on a building façade, Construct. Build. Mater., 2011, vol. 25, pp. 2190–2197. doi 10.1016/j.conbuildmat.2010.10.007Madruga, F.J., Ibarra-Castanedo, C., Conde, O., López-Higuera, J.M., and Maldague, X., Infrared thermography processing based on higher-order statistics, NDT&E Int., 2010, vol. 43, pp. 661–666. doi 10.1016/j.ndteint.2010.07.002Meola, C., Infrared thermography of masonry structures, Infrared Phys. Technol., 2007, vol. 49, no. 3, pp. 228–33. doi 10.1016/j.infraredPosta, J., Dolejs, J., Non-destructive assessment of timber elements with an emphasis on radiometry., Intern. J. Arch. Herit., 2015, vol. 9, no.6.Válek, J., Kruschwitz, S., Wöstmann, J., Kind, T., Valach, J., Köpp, C., and Lesák, J., Nondestructive investigation of wet building material: Multimethodological approach, J. of performance of Constructed Facilities, pp. 462–472. doi 10.1061/(ASCE)CF.1943-5509.000005
Flavour and Collider Interplay for SUSY at LHC7
The current 7 TeV run of the LHC experiment shall be able to probe gluino and
squark masses up to values larger than 1 TeV. Assuming that hints for SUSY are
found in the jets plus missing energy channel by the end of a 5 fb run,
we explore the flavour constraints on three models with a CMSSM-like spectrum:
the CMSSM itself, a Seesaw extension of the CMSSM, and Flavoured CMSSM. In
particular, we focus on decays that might have been measured by the time the
run is concluded, such as and . We also analyse
constraints imposed by neutral meson bounds and electric dipole moments. The
interplay between collider and flavour experiments is explored through the use
of three benchmark scenarios, finding the flavour feedback useful in order to
determine the model parameters and to test the consistency of the different
models.Comment: 44 pages, 15 figures; v3: minor corrections, added references,
updated figures. Version accepted for publicatio
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