Dimensionless analysis of constrained damping treatments

One of the most effective ways of controlling vibrations in plate or beam structures is by means of constrained viscoelastic damping treatments. Contrary to the unconstrained configuration, the design of constrained and integrated layer damping treatments is multifaceted because the thickness of the viscoelastic layer acts distinctly on the two main counterparts of the strain energy the volume of viscoelastic material and the shear strain field. In this work, a parametric study is performed exploring the effect that the design parameters, namely the thickness/length ratio, constraining layer thickness, material modulus, natural mode and boundary conditions have on these two counterparts and subsequently, on the treatment efficiency. This paper presents five parametric studies, namely, the thickness/length ratio, the constraining layer thickness, material properties, natural mode and boundary conditions. The results obtained evidence an interesting effect when dealing with very thin viscoelastic layers that contradicts the standard treatment efficiency vs. layer thickness relation; hence, the potential optimisation of constrained and integrated viscoelastic treatments through the use of properly designed thin multilayer configurations is justified. This work presents a dimensionless analysis and provides useful general guidelines for the efficient design of constrained and integrated damping treatments based on single or multi-layer configurations. (C) 2012 Elsevier Ltd. All rights reserved

Holocene slip rate variability along the Pernicana fault system (Mt. Etna, Italy): Evidence from offset lava flows

The eastern flank of the Mount Etna stratovolcano is affected by extension and is slowly sliding eastward into the Ionian Sea. The Pernicana fault system forms the border of the northern part of this sliding area. It consists of three E-W−oriented fault sectors that are seismically active and characterized by earthquakes up to 4.7 in magnitude (M) capable of producing ground rupture and damage located mainly along the western and central sectors, and by continuous creep on the eastern sector. A new topographic study of the central sector of the Pernicana fault system shows an overall bell-shaped profile, with maximum scarp height of 35 m in the center of the sector, and two local minima that are probably due to the complex morphological relation between fault scarp and lava flows. We determined the ages of lava flows cut by the Pernicana fault system at 12 sites using cosmogenic 3He and 40Ar/39Ar techniques in order to determine the recent slip history of the fault. From the displacement-age relations, we estimate an average throw rate of ∼2.5 mm/yr over the last 15 k.y. The slip rate appears to have accelerated during the last 3.5 k.y., with displacement rates of up to ∼15 mm/yr, whereas between 3.5 and 15 ka, the throw rate averaged ∼1 mm/yr. This increase in slip rate resulted in significant changes in seismicity rates, for instance, decreasing the mean recurrence time of M ≥ 4.7 earthquakes from ∼200 to ∼20 yr. Based on empirical relationships, we attribute the variation in seismic activity on the Pernicana fault system to factors intrinsic to the system that are likely related to changes in the volcanic system. These internal factors could be fault interdependencies (such as those across the Taupo Rift, New Zealand) or they could represent interactions among magmatic, tectonic, and gravitational processes (e.g., Kīlauea volcano, Hawaii). Given their effect on earthquake recurrence intervals, these interactions need to be fully assessed in seismic hazard evaluations

Double-duty actions for ending malnutrition within a decade

Malnutrition has many forms. Undernutrition can see children dangerously thin for their height (wasting), or their growth permanently impeded (stunting). Inadequate intake of key nutrients may weaken immune systems, impair brain development, and worsen the risk of conditions such as anaemia and blindness. Diets rich in calories well beyond the body's metabolic needs drive the burden of overweight and obesity, while excess dietary fat, sugar, and salt can increase the risks of non-communicable diseases (NCDs)

Virtual is so real! Consumers' evaluation of product packaging in virtual reality

Virtual Reality (VR) is shaping all human activities, and with the advent of the metaverse, buyers are going to experience new ways of doing shopping. What would happen if consumers will be asked to assess a product's attribute, i.e., packaging, in a virtual environment, instead of being able to physically hold the product, like in a traditional purchasing process? The aim of this study is to analyze consumers' evaluation of packaged products in immersive VR, manipulating packaging structural and haptic cues, and clarify potential differences with the consumers' responses in the real life. We conducted two focus groups (Study 1), with 16 participants, a mixed design experiment (Study 2), involving 167 consumers, to analyze consumers' attitudes, and a choice-based conjoint analysis (Study 3), with 41 individuals, to study actual choice behavior. The main findings reveal that consumer behavior in VR is consistent with everyday life, except for minor variations. VR proves to be an efficient and rigorous research environment, also suitable for testing sensory cues and non-tangible attributes. Finally, the article suggests managers can effectively use VR for product and packaging development, through a more sustainable process that requires fewer resources and time compared to traditional testsinfo:eu-repo/semantics/publishedVersio

Self-report of Cognition and Objective Test Performance in Posttraumatic Headache

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74675/1/j.1526-4610.1996.3605300.x.pd

Endobronchial Perineurioma: An Unusual Soft Tissue Lesion in an Unreported Location

We report the first case of an endobronchial perineurioma, a rare benign neoplasm typically occurring in soft tissue. A 53-year-old nonsmoking female presented with a three-month history of persistent bronchitis. A CT scan followed by bronchoscopy demonstrated an endobronchial lesion involving the left mainstem bronchus. Removal of the lesion by bronchoscopy was accomplished. The tumor was composed of bland spindle cells in a variably collagenized stroma. These cells had long cytoplasmic processes. No mitotic activity or necrosis was observed. Neoplastic cells were immunoreactive for epithelial membrane antigen (EMA), CD34, and claudin-1. Smooth muscle actin (SMA), desmin, and S-100 immunostains were all negative. Based on the morphologic appearance and immunophenotype, a diagnosis of perineurioma was rendered

Diferenças de género e de idade na prática de modalidades em ginásio/academia

Com o presente estudo pretendeu-se saber o que leva os utentes a frequentarem um ginásio/academia, tendo como suporte a sua perspectiva. Aplicou-se um questionário a 129 utentes: 94 mulheres e 35 homens, com idades entre os 17 e 73 anos. Os utentes que mais frequentam o ginásio são os que têm idades inferiores a 30 anos e superiores a 50 anos. Recorrem a diferentes atividades oferecidas pelo ginásio, desde o Treino Cardiovascular até às aulas de grupo. Não se encontraram diferenças significativas (p>0,05) entre o grupo de menores de 40 anos e o grupo de maiores de 40 anos, nem mesmo entre os que têm ou não têm familiares a seu cargo. Apurámos diferenças estatisticamente significativas (p<0,05) em termos de género nas modalidades de Hidroginástica, Body Balance, Pilates, Musculação e Ginástica Localizada. Na variável idade encontrámos diferenças estatisticamente significativas (p<0,05) relativamente às modalidades de Body Combat, Body Pump, Body Balance, Pilates, Hidroginástica. As modalidades de alto impacto são preferidas pelos menores de 30 anos e as de baixo impacto pelos maiores de 50 anos (P<0.05). Constatamos que os utentes têm conseguido atingir os objetivos que delinearam.CIEC - Centro de Investigação em Estudos da Criança, UM (UI 317 da FCT