Search results for "Minimum"
showing 10 items of 327 documents
New results on kaon decays from NA48
2007
We report on recent results on rare and semileptonic kaon decays from NA48 and NA48/2. Using data from a minimum bias run in 1999 we present a new measurement of the CP violating decay K L → π + π − with over 40000 selected events. We measured the ratio Γ ( K L → π + π − ) / Γ ( K L → π ± e ∓ ν ) = ( 4.835 ± 0.038 ) × 10 −3 leading to the precise determination of the CP violation parameter | η + − | = ( 2.223 ± 0.013 ) × 10 −3 . From the same data we selected over 2 × 10 6 K L → π ± μ ∓ ν decays. Preliminary results from a dalitz plot fit yield the values for the form factors λ + = 0.0260 ± 0.0007 s t a t ± 0.0010 s y s t and λ 0 = 0.0120 ± 0.0008 s t a t ± 0.0015 s y s t . In one month of …
Search for heavy neutral lepton production in K+ decays
2018
A search for heavy neutral lepton production in $K^+$ decays using a data sample collected with a minimum bias trigger by the NA62 experiment at CERN in 2015 is reported. Upper limits at the $10^{-7}$ to $10^{-6}$ level are established on the elements of the extended neutrino mixing matrix $|U_{\ell 4}|^2$ ($\ell=e,\mu$) for heavy neutral lepton mass in the range $170-448~{\rm MeV}/c^2$. This improves on the results from previous production searches in $K^+$ decays, setting more stringent limits and extending the mass range.
Antifungal Activity of Biocontrol Agents In Vitro and Potential Application to Reduce Mycotoxins (Aflatoxin B1 and Ochratoxin A)
2021
Food bio-preservatives are requested as substituents of chemical pesticides in food. The aim of this study was to carry out a screening of twenty biocontrol agents (BCAs) for their potential fungicidal activity in vitro. Twenty BCAs were tested against ten pathogenic fungi. Some of the cell-free supernatants (CFS) tested showed in vitro antifungal activity versus pathogenic fungi. The highest fungicidal activity was observed in the fermented CFS of Paenibacillus chibensis CECT 375, Bacillus amyloliquefaciens CECT 493, and Pantoea agglomerans CECT 850, which showed a minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values of 125 and 250 g/L, respectively. The…
Improved primary regulation for minimum energy losses in islanded microgrids
2017
In this paper, an improved primary regulation is proposed for grid forming units supplying islanded microgrids. A minimum losses Optimal Power Flow is run off-line to devise the operating set points composing the primary regulation curve. In this way, after load perturbations, generators can reach an optimized operating point for a given and unique minimum losses energy flows distribution. The idea is to skip the hierarchical control architecture and provide a feasible and optimized operating point. A case study over 24 hours shows the effectiveness of this new approach as well as the improved operation quality of the system.
Analysis and design of elastic plastic structures subjected to dynamic loads
In the last decades, the concept of “optimization” has reached considerable value in many different fields of scientific research and, in particular, it has assumed great importance in the field of structural mechanics. The present study describes and shows the scientific path followed in the three years of doctoral studies. The state of the art concerning the optimization of elastic plastic structures subjected to quasi-static loads was already well established at the beginning of the Ph.D. course. Actually, it was already faced the study of structures subjected to quasi-static cyclic loads able to ensure different structural behaviors in relation to different intensity levels of the appli…
Optimal design of elastic plastic frames accounting for seismic protection devices
2013
The optimal design of elastic perfectly plastic steel frames with or without suitable protection devices and subjected to static as well as seismic loadings is studied. Two minimum volume problem formulations are proposed, on the grounds of the so-called statical approach, accounting for three different resistance limits: the purely elastic limit, the (elastic) shakedown limit and the instantaneous collapse limit. The adopted load combinations are characterized by the presence of fixed loads, of quasi-static perfect cyclic loads and dynamic (seismic) loads. The linear elastic effects of the dynamic actions are studied by utilizing a modal technique. The proposed treatment is referred to the…
Bounds on transient phase plastic deformations in optimal design of steel frames subjected to cyclic loads
2009
A minimum volume multicriterion design of elastic perfectly plastic steel frames subjected to a combination of quasi-static fixed and cyclic loads, bounding the transient phase plastic deformations, is proposed. The problem is formulated according to a plastic shakedown criterion, so that incremental and instantaneous collapse are certainly prevented when the frame is subjected to very strongly amplified cyclic loads. The further condition that the structure must also behave elastically in serviceability conditions is imposed. Since the steady-state loading history is known it is possible to directly bound the steady-state plastic deformations. By applying a suitable own bounding theorem, i…
Seismic shakedown design of frames based on a probabilistic approach
2014
The present study concerns the optimal design of elastic perfectly plastic structures subjected to a combination of fixed and seismic loads. In particular, plane frames are considered and suitable measures of the beam element cross sections are chosen as design variables. The optimal design is required to behave in a purely elastic manner when subjected just to the fixed load and to have the capability to eventually shakedown when simultaneously subjected to fixed and seismic loads. Due to the natural uncertainness related to the definition of the seismic load history, a new probabilistic approach is proposed, consisting into two subsequent search steps. At first a suitably chosen large num…
Round Table. Nordic unions and the European Minimum Wage Directive
2022
La incidencia del salario mínimo interprofesional en sectores de bajos salarios
2012
El salario mínimo es un tema que ha vuelto a cobrar actualidad. La mayoría de los análisis que se realizan al respecto se centran en determinar si su nivel tiene algún tipo de incidencia sobre el empleo. No obstante, son escasos los trabajos que abordan si efectivamente el salario mínimo cumple con su objetivo básico: mejorar las rentas de los perceptores de bajos salarios. En este trabajo abordamos precisamente esta cuestión. Para ello se analiza la evolución de los salarios en la negociación colectiva en tres sectores considerados de bajos salarios (comercio al por menor, hostelería y limpieza de locales y edificios), centrándonos en los puestos inferiores de la escala salarial. The minim…