6,323 research outputs found
On characters of Chevalley groups vanishing at the non-semisimple elements
Let G be a finite simple group of Lie type. In this paper we study characters
of G that vanish at the non-semisimple elements and whose degree is equal to
the order of a maximal unipotent subgroup of G. Such characters can be viewed
as a natural generalization of the Steinberg character. For groups G of small
rank we also determine the characters of this degree vanishing only at the
non-identity unipotent elements.Comment: Dedicated to Lino Di Martino on the occasion of his 65th birthda
Towards Optimal Energy-Water Supply System Operation for Agricultural and Metropolitan Ecosystems
The energy-water demands of metropolitan regions and agricultural ecosystems
are ever-increasing. To tackle this challenge efficiently and sustainably, the
interdependence of these interconnected resources has to be considered. In this
work, we present a holistic decision-making framework which takes into account
simultaneously a water and energy supply system with the capability of
satisfying metropolitan and agricultural resource demands. The framework
features: (i) a generic large-scale planning and scheduling optimization model
to minimize the annualized cost of the design and operation of the energy-water
supply system, (ii) a mixed-integer linear optimization formulation, which
relies on the development of surrogate models based on feedforward artificial
neural networks and first-order Taylor expansions, and (iii) constraints for
land and water utilization enabling multi-objective optimization. The framework
provides the operational profiles of all energy-water system elements over a
given time horizon, which uncover potential synergies between the essential
food, energy, and water resource supply systems.Comment: Part of the Foundations of Computer-Aided Process Operations and
Chemical Process Control (FOCAPO/CPC) 2023 Proceeding
Almost cyclic elements in cross-characteristic representations of finite groups of Lie type
This paper is a significant contribution to a general programme aimed to
classify all projective irreducible representations of finite simple groups
over an algebraically closed field, in which the image of at least one element
is represented by an almost cyclic matrix (that is, a square matrix of size
over a field with the property that there exists such
that is similar to , where is cyclic
and ). While a previous paper dealt with the Weil
representations of finite classical groups, which play a key role in the
general picture, the present paper provides a conclusive answer for all
cross-characteristic projective irreducible representations of the finite
quasi-simple groups of Lie type and their automorphism groups.Comment: To appear on Journal of Group Theor
La expansión urbana del balneario Monte Hermoso, provincia de Buenos Aires, argentina: problemática ambiental
Monte Hermoso es una localidad costera bonaerense que se caracteriza por la calidad y seguridad de sus playas de aguas cálidas, arenas homogéneas y suave pendiente, lo que constituye el principal atractivo turístico y económico. Se ha convertido en el balneario provincial de mayor crecimiento y expansión de las últimas décadas. El objetivo de este aporte es puntualizar y analizar la situación ambiental del lugar, teniendo en cuenta la expansión urbana y el consecuente impacto en el entorno físico. Se exponen las principales características y consecuencias del desarrollo urbano y ocupación del territorio y cómo la intervención antrópica (construcciones, forestación, extracción de arena, volcado de escombros, tránsito vehicular, generación de residuos sólidos urbanos, efluentes cloacales, extracción de agua subterránea) puede impactar y alterar tanto el equilibrio costero médano-playa como la sustentabilidad del abastecimiento de agua a partir del acuífero libre alojado en los médanos. Planificar la urbanización, con el apoyo de un plan de manejo costero y con la correcta gestión del recurso hídrico, ejerciendo controles sobre la actividad del hombre, es posible preservar la calidad de la playa y la sustentabilidad del abastecimiento de agua en términos de calidad y cantidad
Photopolymerized thermosensitive poly(HPMAlactate)-PEG-based hydrogels : effect of network design on mechanical properties, degradation, and release behavior
Photopolymerized thermosensitive A-B-A triblock copolymer hydrogels composed of poly(N-(2-hydroxypropyl)-methacrylamide lactate) A-blocks, partly derivatizal with methacrylate groups to different extents (10, 20, and 30%) and hydrophilic poly(ethylene glycol) B-blocks of different molecular weights (4, 10, and 20 kDa) were synthesized. The aim of the present study was to correlate the polymer architecture with the hydrogel properties, particularly rheological, swelling, degradation properties and release behavior. It was found that an increasing methacrylation extent and a decreasing PEG molecular weight resulted in increasing gel strength and cross-link density, which tailored the degradation profiles from 25 to more than 300 days. Polymers having small PEG blocks showed a remarkable phase separation into polymer- and water-rich domains, as demonstrated by confocal microscopy. Depending on the hydrophobic domain density, the loaded protein resides in the hydrophilic pores or is partitioned into hydrophilic and hydrophobic domains, and its release from these compartments is tailored by the extent of methacrylation and by PEG length, respectively. As the mechanical properties, degradation, and release profiles can be fully controlled by polymer design and concentration, these hydrogels are suitable for controlled protein release
Three years field trials to assess the effect of kaolin made particles and copper on olive-fruit fly (B.oleae Gmelin) infestations in Sicily
In most countries of Mediterranean Basin, Bactrocera oleae (Gmel), the olive fruit fly, is the key pest insect on olives. In Sicily this pest causes losses of fruits and a poor quality olive oil. Many researchers have recently carried out some field studies which were based on the use of kaolin and copper against the olive-fruit fly. In the last years these products have been effective several times in reducing olive fly infestation. Kaolin had, also, some important effect in reducing heat-stress in fruit crops and olive-trees.
The aim of the present study was to assess the effect of kaolin and copper treatment on olive infestations in Sicily and to evaluate chemical and sensory parameters of oils extracted. For this reason, within 2003-2005, the IX Servizio of Assessorato Regionale Agricoltura e Foreste, selected some olive groves where to carry out trials with kaolin and copper and to realize information and divulgation activities
Lifetime glucocorticoid profiles in baleen of right whale calves: Potential relationships to chronic stress of repeated wounding by Kelp Gulls
Baleen tissue accumulates stress hormones (glucocorticoids, GC) as it grows, along with other adrenal, gonadal and thyroid hormones. The hormones are deposited in a linear fashion such that a single plate of baleen allows retrospective assessment and evaluation of long-term trends in the whales´ physiological condition. In whale calves, a single piece of baleen contains hormones deposited across the lifespan of the animal, with the tip of the baleen representing prenatally grown baleen. This suggests that baleen recovered from stranded carcasses of whale calves could be used to examine lifetime patterns of stress physiology. Here we report lifetime profiles of cortisol and corticosterone in baleen of a North Atlantic right whale ("NARW" - Eubalaena glacialis) calf that died from a vessel strike, as well as four southern right whale ("SRW" - Eubalaena australis) calves that were found dead with varying severity of chronic wounding from Kelp Gull (Larus dominicanus) attacks. In all five calves, prenatally grown baleen exhibited a distinctive profile of elevated glucocorticoids that declined shortly before birth, similar to GC profiles reported from baleen of pregnant females. After birth, GC profiles in calf baleen corresponded with the degree of wounding. The NARW calf and two SRW calves with no or few gull wounds had relatively low and constant GC content throughout life, while two SRW calves with high numbers of gull wounds had pronounced elevations in baleen GC content in postnatal baleen followed by a precipitous decline shortly before death, a profile suggestive of prolonged chronic stress. Baleen samples may present a promising and valuable tool for defining the baseline physiology of whale calves and may prove useful for addressing conservation-relevant questions such as distinguishing acute from chronic stress and, potentially, determining cause of death.Fil: Ajó, Alejandro A. Fernández. Northern Arizona University; Estados UnidosFil: Hunt, Kathleen E.. Northern Arizona University; Estados UnidosFil: Uhart, Marcela María. University of California at Davis; Estados UnidosFil: Rowntree, Victoria. University of Utah; Estados UnidosFil: Sironi, Mariano. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Diversidad Biológica y Ecológica; Argentina. Instituto de Conservación de Ballenas; ArgentinaFil: Marón, Carina Flavia. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento de Diversidad Biológica y Ecológica; Argentina. Instituto de Conservación de Ballenas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Di Martino, Matias. Southern Right Whale Health Monitoring Program; ArgentinaFil: Buck, Charles Loren. Northern Arizona University; Estados Unido
Characterization of Strombolian events by using independent component analysis
We apply Independent Component Analysis (ICA) to seismic signals recorded at Stromboli volcano. Firstly, we show how ICA works considering synthetic signals, which are generated by dynamical systems. We prove that Strombolian signals, both tremor and explosions, in the high frequency band (>0.5 Hz), are similar in time domain. This seems to give some insights to the organ pipe model generation for the source of these events. Moreover, we are able to recognize in the tremor signals a low frequency component (<0.5 Hz), with a well defined peak corresponding to 30s
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