Effect of the curing time on the numerical modelling of the behaviour of a chemically stabilised soft soil

The ability of the Modified Cam Clay (MCC) model combined with the Von Mises (VM) model, considering the effect of curing time on the enhancement of the mechanical properties of a chemically stabilised soft soil is examined. The evolution of the strength and stiffness over time is based on the results of undrained compressive strength (UCS) tests carried out for different curing times (from 28 days to 360 days). Initially, the MCC/VM models associated with the effect of curing time are validated by CIU triaxial tests, for curing times of 28 and 90 days. Finally, the behaviour of an embankment built on a soft soil reinforced with deep mixing columns is predicted based on the previously validated models. The results show that the increase of curing time of the DMCs slightly decreases the settlement obtained with a curing time of 28 days

Natural History Of The Neotropical Arboreal Ant, Odontomachus Hastatus: Nest Sites, Foraging Schedule, And Diet.

The ecology of most arboreal ants remains poorly documented because of the difficulty in accessing ant nests and foragers in the forest canopy. This study documents the nesting and foraging ecology of a large (∼13 mm total length) arboreal trap-jaw ant, Odontomachus hastatus (Fabricius) (Hymenoptera: Formicidae) in a sandy plain forest on Cardoso Island, off the coast of Southeast Brazil. The results showed that O. hastatus nested in root clusters of epiphytic bromeliads, most commonly Vriesea procera (70% of nest plants). Mature O. hastatus colonies include one to several queens and about 500 workers. Foraging by O. hastatus is primarily nocturnal year-round, with increased foraging activity during the wet/warm season. The foragers hunt singly in the trees, preying on a variety of canopy-dwelling arthropods, with flies, moths, ants, and spiders accounting for > 60% of the prey captured. Although predators often have impacts on prey populations, the ecological importance of O. hastatus remains to be studied.124

Systematic evaluation of software product line architectures

The architecture of a software product line is one of its most important artifacts as it represents an abstraction of the products that can be generated. It is crucial to evaluate the quality attributes of a product line architecture in order to: increase the productivity of the product line process and the quality of the products; provide a means to understand the potential behavior of the products and, consequently, decrease their time to market; and, improve the handling of the product line variability. The evaluation of product line architecture can serve as a basis to analyze the managerial and economical values of a product line for software managers and architects. Most of the current research on the evaluation of product line architecture does not take into account metrics directly obtained from UML models and their variabilities; the metrics used instead are difficult to be applied in general and to be used for quantitative analysis. This paper presents a Systematic Evaluation Method for UML-based Software Product Line Architecture, the SystEM-PLA. SystEM-PLA differs from current research as it provides stakeholders with a means to: (i) estimate and analyze potential products; (ii) use predefined basic UML-based metrics to compose quality attribute metrics; (iii) perform feasibility and trade-off analysis of a product line architecture with respect to its quality attributes; and, (iv) make the evaluation of product line architecture more flexible. An example using the SEI’s Arcade Game Maker (AGM) product line is presented as a proof of concept, illustrating SystEM-PLA activities. Metrics for complexity and extensibility quality attributes are defined and used to perform a trade-off analysis

Impulsive dirac-delta forces in the rocking motion

In this work the classical theory of one block rocking motion is revisited. A Dirac-delta type interaction as impact mechanism is found to be an alternative for the traditional model. Numerical computations with this new formulation have shown that the agreement with the classical theory is excellent for the case of slender blocks and small displacements. Good agreement with experimental data has also been found for the case of arbitrary angles and slenderness. A probabilistic study of the variations in the coe cient of restitution due to the cyclic degradation at corners during seismic action is also performed. The approach presented in this paper opens new lines for further theoretical developments and computational applications

Towards e-Cities: an Atlas to enhance the public realm through interactive urban cyber-physical devices

Cyber-physical devices are the backbone of a postdigital society in which the virtual and real spaces are seamlessly integrated by ubiquitous computing and networking. The incorporation of such devices in public space is a central subject of a strategic Research Project that gathers a multidisciplinary team from architecture, product design, polymer science and ICT R&D units. This paper frames the key roles of public space and ICTs for UN Sustainable Development Goals and sustainable smart cities. It also reports the architecture R&D unit review on the relations between public space, community, environment and digital interfaces. This review was materialized in an Atlas that collects, classifies and relates a corpus of heterogeneous urban cyber-physical projects case studies. We expand on three main framing concepts (Digital Twin, Interface, Awareness) and identify trends on the devices’ design and deployment strategies to counteract digitally hostile environments and early obsolescence. We also suggest the rising of new types of urban devices aiming at expanding the liveliness of urban places, the knowledge of urban life and the users’ environmental consciousness. The lessons learned from the Atlas fed the design guidelines for a developing demonstrator of a new breed of environmentally sensible interactive urban devices.Work co-funded by European Regional Development Fund (ERDF) thru Norte 2020: Project “Lab4U&Spaces - Living Lab of Interactive Urban Space Solution” (NORTE-01-0145-FEDER-000072); and Project Lab2PT - Landscapes, Heritage and Territory laboratory - UIDB/04509/2020 thru FCT - Fundação para a Ciência e a Tecnologia

Water-like hierarchy of anomalies in a continuous spherical shouldered potential

We investigate by molecular dynamics simulations a continuous isotropic core-softened potential with attractive well in three dimensions, introduced by Franzese [cond-mat/0703681, to appear on Journal of Molecular Liquids], that displays liquid-liquid coexistence with a critical point and water-like density anomaly. Here we find diffusion and structural anomalies. These anomalies occur with the same hierarchy that characterizes water. Yet our analysis shows differences with respect to the water case. Therefore, many of the anomalous features of water could be present in isotropic systems with soft-core attractive potentials, such as colloids or liquid metals, consistent with recent experiments showing polyamorphism in metallic glasses.Comment: 27 pages, 9 figures. to appear in J. Chem. Phy