Multiobjective evolutionary algorithms for multivariable PI controller design

A multiobjective optimisation engineering design (MOED) methodology for PI controller tuning in multivariable processes is presented. The MOED procedure is a natural approach for facing multiobjective problems where several requirements and specifications need to be fulfilled. An algorithm based on the differential evolution technique and spherical pruning is used for this purpose. To evaluate the methodology, a multivariable control benchmark is used. The obtained results validate the MOED procedure as a practical and useful technique for parametric controller tuning in multivariable processes.This work was partially supported by the FPI-2010/19 grant and the project PAID-06-11 from the Universitat Politecnica de Valencia and the projects DPI2008-02133, TIN2011-28082 and ENE2011-25900 from the Spanish Ministry of Science and Innovation.Reynoso Meza, G.; Sanchís Saez, J.; Blasco Ferragud, FX.; Herrero Durá, JM. (2012). Multiobjective evolutionary algorithms for multivariable PI controller design. Expert Systems with Applications. 39(9):7895-7907. https://doi.org/10.1016/j.eswa.2012.01.111S7895790739

All-particle cosmic ray energy spectrum measured with 26 IceTop stations

We report on a measurement of the cosmic ray energy spectrum with the IceTop air shower array, the surface component of the IceCube Neutrino Observatory at the South Pole. The data used in this analysis were taken between June and October, 2007, with 26 surface stations operational at that time, corresponding to about one third of the final array. The fiducial area used in this analysis was 0.122 km^2. The analysis investigated the energy spectrum from 1 to 100 PeV measured for three different zenith angle ranges between 0{\deg} and 46{\deg}. Because of the isotropy of cosmic rays in this energy range the spectra from all zenith angle intervals have to agree. The cosmic-ray energy spectrum was determined under different assumptions on the primary mass composition. Good agreement of spectra in the three zenith angle ranges was found for the assumption of pure proton and a simple two-component model. For zenith angles {\theta} < 30{\deg}, where the mass dependence is smallest, the knee in the cosmic ray energy spectrum was observed between 3.5 and 4.32 PeV, depending on composition assumption. Spectral indices above the knee range from -3.08 to -3.11 depending on primary mass composition assumption. Moreover, an indication of a flattening of the spectrum above 22 PeV were observed.Comment: 38 pages, 17 figure

Search for Gravitational Waves from Intermediate Mass Binary Black Holes

We present the results of a weakly modeled burst search for gravitational waves from mergers of non-spinning intermediate mass black holes (IMBH) in the total mass range 100--450 solar masses and with the component mass ratios between 1:1 and 4:1. The search was conducted on data collected by the LIGO and Virgo detectors between November of 2005 and October of 2007. No plausible signals were observed by the search which constrains the astrophysical rates of the IMBH mergers as a function of the component masses. In the most efficiently detected bin centered on 88+88 solar masses, for non-spinning sources, the rate density upper limit is 0.13 per Mpc^3 per Myr at the 90% confidence level.Comment: 13 pages, 4 figures: data for plots and archived public version at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=62326, see also the public announcement at http://www.ligo.org/science/Publication-S5IMBH

A Mass-Transfer Model for the Drying of an Innovative Tomato Gel

Partially dehydrated tomato gels are innovative food products of extended shelf life for using in snack preparations. Flexible, sheet-shaped product was obtained by a pectic gelation mechanism induced by dehydration, starting from a formulation based on tomato puree. The drying kinetics of this product was studied in a bench-scale tray dryer operating between 40 and 80 8C at an air velocity of 2 m/s. The &apos;in-dryer&apos; weighings of the trays allowed accurate experimental data to be recorded. The observed drying curves were modeled in two stages: for high moisture contents, with a constant drying rate model while at lower moistures, with an analytical-diffusive model, solved for the average sheet thickness. The mass-transfer Biot number in the diffusive model was found to be 1.1, indicating that external and internal resistances to mass-transfer are comparable. An Arrhenius model correctly described the temperature dependence of the water diffusion coefficient in the tomato pectic gel, represented by an activation energy of 22.0 kJ/mol. The model can be used to estimate minimum drying times and can be incorporated in tray dryer simulators for computer prototyping of new designs, and optimization of existing drying facilities

Recycling of environmentally problematic plant wastes generated from greenhouse tomato crops through vermicomposting

The enormous quantity of plant waste produced from greenhouse tomato crops is an environmental problem that should be solved by recycling that waste into valuable organic products through low-cost technologies, such as vermicomposting. Feasibility of vermicomposting greenhouse tomato-plant waste (P) using paper-mill sludge (S) as complementary waste was investigated by this study. Earthworm development in P, S, and two mixtures of both wastes was monitored over 24 weeks and compared with that in cow dung (D), an optimum organic-waste to be vermicomposted. The effectiveness of vermicomposting to biostabilize those wastes was assessed by analysing phospholipid fatty acid composition, chemical features, plant-nutrient content, metal concentration, enzyme activities, and germination index (GI). A commercial vermicompost was also analyzed and taken as a reference of vermicompost quality. Earthworms did not survive in P alone, but a mixture of P with S at a ratio of 2:1 or 1:1 resulted in earthworm development similar to that observed in D. Phospholipid fatty acid analysis revealed that earthworm activity strongly transformed initial microbiota inhabiting the wastes, giving rise to vermicompost microbial communities which were similar to that of a commercial vermicompost. Both mixtures of P and S were properly biostabilized through vermicomposting, as indicated by decreases in their C:N ratio and enzyme activities together with increases in their degree of maturity (GI ~ 100 %) after the process. This study demonstrates that the vermicomposting of tomato-plant waste together with paper-mill sludge allows the recycling of both wastes, thereby improving the environmental sustainability of greenhouse crops

X chromosome painting in Microtus: Origin and evolution of the giant sex chromosomes

Abstract Sex chromosomes in species of the genus Microtus present some characteristic features that make them a very interesting group to study sex chromosome composition and evolution. M. cabrerae and M. agrestis have enlarged sex chromosomes (known as &apos;giant sex chromosomes&apos;) due to the presence of large heterochromatic blocks. By chromosome microdissection, we have generated probes from the X chromosome of both species and hybridized on chromosomes from six Microtus and one Arvicola species. Our results demonstrated that euchromatic regions of X chromosomes in Microtus are highly conserved, as occurs in other mammalian groups. The sex chromosomes heterochromatic blocks are probably originated by fast ampli¢cation of different sequences, each with an independent origin and evolution in each species. For this reason, the sex heterochromatin in Microtus species is highly heterogeneous within species (with different composition for the Y and X heterochromatic regions in M. cabrerae) and between species (as the composition of M. agrestis and M. cabrerae sex heterochromatin is different). In addition, the X chromosome painting results on autosomes of several species suggest that, during karyotypic evolution of the genus Microtus, some rearrangements have probably occurred between sex chromosomes and autosomes

Magnetism in segregated bimetallic CoRh nanoclusters

Abstract The magnetic properties of free-standing Co n Rh m clusters (N ¼ n þ m % 110 and n % m) of three different symmetries: cubo-octahedral, icosahedral and HCP, were investigated in the segregated case. The initial geometrical structures constructed at Rh bulk distances were relaxed with a many-body Gupta potential to obtain the cluster geometries and energies. We find that the lowest energy is associated with the HCP structure. The relaxed interatomic distance for all the structures is slightly lower than the Rh bulk distance. The spin-polarized electronic structure and related magnetic properties of these optimized geometries were calculated by solving self-consistently a spd tightbinding Hamiltonian. The magnetic moment of the Rh atoms shows strong dependence on the position and environment, whereas the Co atoms show a smoother dependence. Results are compared with the experimental data and with other theoretical calculations available in the literature.

Effect of polyethylene glycol on in vitro gas production of some non-leguminous forage trees in tropical region of the south of Mexico

The aim of this study was to evaluate the chemical composition of five foliages, and the effect of adding PEG during incubation on in vitro gas production (GP), metabolizable energy (ME), partitioning factor (PF24h), in vitro organic matter digestibility (OMD), short chain fatty acids (SCFA) and microbial biomass production (MBP) as tools to detect the adverse effect of tannins in the foliage of non-leguminous trees.The objective of the current study was to evaluate the chemical composition and the in vitro gas production (GP) of some non-leguminous forage trees in presence or absence of polyethylene glycol (PEG). Guazuma ulmifolia, Crescentia alata, Ficus glabrata, Ficus cotinifolia, Spondias purpurea, Mangifera indica, Licania arborea, Simira mexicana were collected during the rainy season, in the Bejucos locality, State of Mexico. Metabolizable energy (ME), partitioning factor (PF24h), in vitro organic matter digestibility (OMD), short chain fatty acids (SCFA) and microbial biomass production (MBP) were estimated as tools to detect the adverse effects of tannins in tree foliage. The chemical composition data were analyzed in a random design, and the in vitro digestion parameters on a randomized design with 8 9 2 factorial arrangement. Chemical composition showed a wide variation (P\0.05) between species. The use of PEG increased (P\0.05) GP from the foliage of S. purpurea, L. arborea, F. glabrata and G. ulmifolia, showing activity of total phenolics and condensed tannins. Similarly, ME (5.9 MJ kg-1 DM), OMD (354.5 g kg-1 DM) and SCFA (2.3 mol/150 mL) increased (P\0.05); it was higher for S. purpurea, because of the PEG addition effect. The PF24h and MBP were different between species (P\0.05), and decreased due to PEG addition (P\0.05); the species with lower production was S. purpurea. It could be concluded that S. purpurea and F. cotinifolia represent important sources of fodder for livestock in the south region of Mexico