Temperature measurements of expansion products from shock compressed materials using high-speed spectroscopy

Results from spectral radiance measurements using optical multi-channel analyzer over the visible and near infrared regime provide estimates of temperature from expansion products resulting from shocked materials. Specifically, we have made spectral radiance measurements over the wavelength regime of 300–1500 nm. Experiments conducted on aluminum, cerium, and Composition-B high explosive span a wide regime of E/E_v, where E is the internal energy increase of the shocked material, and E_v, is the specific energy required to vaporize the material. For the materials investigated, the ratio is ∼1, 3 and 5 for aluminum, cerium, and Composition-B, respectively. The basic assumption made to deduce these temperatures is that the debris cloud is radiating as a blackbody with emissivity of one and independent of the wavelength. We are also assuming that the probe is monitoring the debris, which is at a single temperature and that there is no spatial temperature gradient. Temperatures at or above the boiling point are confirmed for aluminum and cerium, while the results for Composition-B provide the time-dependent temperature expansion history for shocked Composition-B over the stress regime of 28–130 GPa. These are the first measurements of temperature obtained from the expansion products from materials that have been shocked to very high pressures.     

FMS Approach to Construction Automation

The need to increase safety, productivity, quality, and resource efficiency in construction is a challenge to researchers that requires bold innovative changes. Technological adaptation of successful concepts from other industries to construction offers an important path for innovative progress. This paper provides insight into some central aspects of flexible manufacturing systems (FMS) that show the greatest transferability to construction. A flexible manufacturing system is a production facility consisting of computer‐controlled machines, or work stations, connected by an automated material‐handling system, which is used to produce a variety of parts in low and medium volume. The state of the art in automated material handling and process planning is presented as a basis for construction automation, a new field of civil engineering. Ongoing research in flexible construction systems is described, and directions for future research needed to establish a knowledge base of principles relating to construction automation are outlined.     

In Situ Investigation of Dendrite Deformation During Upward Solidification of Al-7wt.%Si

The in situ investigation of dendrite deformation during solidification processing is an ongoing challenge because of the technical difficulties in carrying out experimental observations and direct measurements in metallic systems that are opaque to visible light and have a high melting temperature. Over the last 20 years, x-ray imaging has been established as a method of choice to overcome this experimental barrier by taking advantage of the increased capabilities of third-generation synchrotron x-ray sources, providing information on growth process and semisolid deformation that is not available otherwise. In this article, we present results showing that the unique combination of synchrotron x-ray radiography and synchrotron white beam x-ray topography can help to reveal the deformations that dendritic microstructures undergo during the upward directional solidification of Al-7wt.%Si alloys. Particular focus will be placed on the bending phenomena of dendrites because of gravity, which may precede fragmentation in the case of well-developed secondary arms.     

Current daylighting design practice: a survey

What are the current daylighting design practices among design teams with an explicit interest in sustainable design? A survey was undertaken: (1) to understand which daylight performance indicators and design tools are currently used by design practitioners to integrate daylighting in their projects; (2) to identify the additional information needed beyond that available in current design guides; and (3) to advise on the content and format of a new daylighting design guide that addresses these needs. The responses obtained from 177 participants showed that over 90% of the practitioners surveyed support the development of a new daylighting design guide that would provide online access to both simple calculation methods as well as more advanced daylighting design tools. Survey results also showed that a variety of non-standardized daylight prediction methods – primarily rules of thumb – are currently being used, and that there is no commonly acknowledged method of how to assess the performance and quality of a daylighting system in terms of energy savings, glare prevention, daylight factors, and the view to the outside.

Quelles sont actuellement les pratiques conceptuelles en matière d'éclairage naturel dans les bureaux d'étude s'intéressant de manière explicite à la conception durable? Une étude a été entreprise pour (1) comprendre quels indicateurs de performances d'éclairage naturel et outils de conception sont actuellement utilisés par les bureaux d'étude pour intégrer l'éclairage naturel dans leurs projets; (2) identifier les informations complémentaires nécessaires en plus de celles qui sont disponibles dans les guides de conception; (3) conseiller sur le contenu et le format d'un nouveau guide de conception sur l'éclairage naturel pour répondre à ces besoins. Les réponses fournies par 177 participants montrent que plus de 99% des praticiens interrogés sont en faveur de la préparation d'un nouveau guide de conception sur l'éclairage naturel qui donnerait accès en ligne à la fois à des méthodes de calcul simples et à des outils de conception d'éclairage naturel plus complexes. Les résultats de cette enquête montrent également que plusieurs méthodes de prédiction de l'éclairage naturel non normalisées, principalement empiriques, sont actuellement utilisées et qu'il n'existe aucune méthode reconnue d'évaluation des performances et de la qualité d'un système d'éclairage naturel en termes d'économies d'énergie, de prévention de l'éblouissement, de coefficient d'éclairage diurne et de vue sur l'extérieur.

éclairage naturel, paramètres de l'éclairage naturel, guide de conception, pratiques conceptuelles, outils de conception, indicateurs de performances, conception durable     

The effects of varying dietary n-6 to n-3 fatty acid ratios on platelet reactivity, coagulation screening assays, and antithrombin III activity in dogs

Thirty beagles were placed on diets containing ratios of n-6 to n-3 fatty acids ranging from 5:1 to 100:1 for 12 weeks to determine the effects of these diets on platelet reactivity, coagulation screening assays, and antithrombin III activity. Although small changes were observed in adenosine diphosphate (ADP)-, collagen-, and arachidonic acid-induced platelet aggregation and 14C-serotonin release, fibrinogen concentrations, and antithrombin III activities during the 12-week study, these changes were not of clinical significance and did not correlate with the varying ratios of n-6 to n-3 fatty acids.     

The daylighting dashboard – A simulation-based design analysis for daylit spaces

This paper presents a vision of how state-of-the-art computer-based analysis techniques can be effectively used during the design of daylit spaces. Following a review of recent advances in dynamic daylight computation capabilities, climate-based daylighting metrics, occupant behavior and glare analysis, a fully integrated design analysis method is introduced that simultaneously considers annual daylight availability, visual comfort and energy use: Annual daylight glare probability profiles are combined with an occupant behavior model in order to determine annual shading profiles and visual comfort conditions throughout a space. The shading profiles are then used to calculate daylight autonomy plots, energy loads, operational energy costs and green house gas emissions. The paper then shows how simulation results for a sidelit space can be visually presented to simulation non-experts using the concept of a daylighting dashboard. The paper ends with a discussion of how the daylighting dashboard could be practically implemented using technologies that are available today.     

Hypertension in the elderly

Elevated blood pressure, especially isolated systolic hypertension, is increasingly frequent with advancing age, affecting 1/4 of all 80-year-olds. Systolic hypertension is associated with increased cardiovascular morbidity and mortality. Recent studies have clearly demonstrated that antihypertensive treatment in the elderly decreases cardiovascular morbidity and mortality (in absolute numbers several times more than in younger patients), without more frequent side effects or a decrease in quality of life. Hypertension in the elderly thus deserves proper attention and should be taken seriously.