2,591 research outputs found
Records of miro (Podocarpus ferrugineus) and other species from inland Canterbury, New Zealand (Note)
STRATEGIC AGRIBUSINESS OPERATION REALIGNMENT IN THE TEXAS PRISON SYSTEM
Mathematical programming-based systems analysis is used to examine the consequences of alternative operation configuration for the agricultural operations within the Texas Department of Criminal Justice. Continuation versus elimination of the total operation as well as individual operating departments are considered. Methodology includes a firm systems operation model combined with capital budgeting and an integer programming based investment model. Results indicate the resources realize a positive return as a whole, but some enterprises are not using resources profitably. The integer investment model is found to be superior for investigating whether to continue multiple interrelated enterprises.agribusiness, enterprise selection, mathematical programming, optimal enterprise organization, Agribusiness,
An economic insight into additive manufacturing system implementation
With an ever growing diffusion of Additive Manufacturing (AM) system in industrial and commercial level, as well as the direct and indirect dynamics which are being introduced resulting from its inclusion as a possible production technology on companies’ portfolio, the need to reconfigure production system and adapt the production strategy becomes even more relevant than before. There are several studies which have emphasized on the importance of a paradigm shift in order to exploit advantages of AM, not only considering changes within design and functionality of the product, but also concerning AM’s impact on the entire value chain (re)configuration. Thus, it is of crucial importance to take into consideration that for this shift to be feasible and manageable, there is a need to include both technical and managerial aspects of manufacturing. This work proposes an economic insight in order to provide a guideline for the proper evaluation of AM system implementation. © IFIP International Federation for Information Processing 2015
Nonlinear dynamic analysis and seismic fragility assessment of a corrosion damaged integral bridge
Purpose
In this paper the impact of corrosion of reinforcing steel in RC columns on the seismic performance of a multi-span concrete integral bridge is explored. A new constitutive model for corroded reinforcing steel is used. This model simulates the buckling of longitudinal reinforcement under cyclic loading and the impact of corrosion on buckling strength. Cover concrete strength is adjusted to account for corrosion induced damage and core concrete strength and ductility is adjusted to account for corrosion induced damage to transverse reinforcement. This study evaluates the impact which chloride induced corrosion of the reinforced concrete columns on the seismic fragility of the bridge. Fragility curves are developed at a various time intervals over the lifetime. The results of this study show that the bridge fragility increases significantly with corrosion.
Design/methodology/approach
This paper firstly evaluates the impact which chloride induced corrosion of the columns has on bridge fragility. Finally, fragility curves are developed at various time intervals over the lifetime of the bridge. The results of this study show that the bridge fragility increases significantly with corrosion.
Findings
1) It was found that columns dominate the system fragility at all levels of deterioration. Therefore, it highlights the importance of good column design in terms of both seismic detailing and durability for this integral bridge type.
2) In terms of foundation settlement coupled with corrosion, it was found that settlements on the order of the discrete levels adopted for this study increased the system fragility at the slight, moderate and extensive damage states but their impact at the complete damage states is negligible.
3) Ageing considerations are currently neglected in widespread regional risk assessment and loss estimation packages for transport infrastructure. The result of this study provides a methodology that enables bridge managers and owners to employ in seismic risk assessment of existing aging bridges.
Originality/value
The modelling technician developed in this paper considers the impact of detailed corrosion damaged of RC column on nonlinear dynamic response and fragility of a corroded integral bridge under earthquake loading. The current modelling technique is the most comprehensive 3D fibre element model for seismic analysis and risk assessment of corroded bridges.
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Interactions between Magnetic Nanowires and Living Cells : Uptake, Toxicity and Degradation
We report on the uptake, toxicity and degradation of magnetic nanowires by
NIH/3T3 mouse fibroblasts. Magnetic nanowires of diameters 200 nm and lengths
comprised between 1 {\mu}m and 40 {\mu}m are fabricated by controlled assembly
of iron oxide ({\gamma}-Fe2O3) nanoparticles. Using optical and electron
microscopy, we show that after 24 h incubation the wires are internalized by
the cells and located either in membrane-bound compartments or dispersed in the
cytosol. Using fluorescence microscopy, the membrane-bound compartments were
identified as late endosomal/lysosomal endosomes labeled with lysosomal
associated membrane protein (Lamp1). Toxicity assays evaluating the
mitochondrial activity, cell proliferation and production of reactive oxygen
species show that the wires do not display acute short-term (< 100 h) toxicity
towards the cells. Interestingly, the cells are able to degrade the wires and
to transform them into smaller aggregates, even in short time periods (days).
This degradation is likely to occur as a consequence of the internal structure
of the wires, which is that of a non-covalently bound aggregate. We anticipate
that this degradation should prevent long-term asbestos-like toxicity effects
related to high aspect ratio morphologies and that these wires represent a
promising class of nanomaterials for cell manipulation and microrheology.Comment: 21 pages 12 figure
Red-Cockaded Woodpecker Status and Management: West Gulf Coastal Plain and Interior Highlands
Red-cockaded woodpecker populations declined precipitously following European settlement and expansion and cutting of the original pine forests across the southeastern United States. By 1990 most residual populations lacked demographic viability, existed in degraded habitat, and were isolated from other populations. The primary causes of this situation were harvest of the original pine forests of the southeastern United States, conversion of forested lands to other uses, short-rotation silvicultural practices, and alteration of the fire regime in the regenerated forests. As social and legal mandates changed, management of red-cockaded woodpeckers became a higher priority. Intensive management for red-cockaded woodpeckers is currently practiced on most public and a few private lands that still support populations. Recent population trends and the current status of red-cockaded woodpeckers in Oklahoma, Arkansas, Texas, and Louisiana reflect historical factors and the efficacy of recent management
Why do people fail to turn good intentions into action? : The role of executive control processes in the translation of healthy eating intentions into action in young Scottish adults
Non peer reviewedPublisher PD
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