Design of a cost effective small span tensile roof

Tensile Structures offer a wide variety of membrane forms however, due to the interdependence of form and structural behaviour, only few forms have so far been built. The increasing need for building new tensile forms and investigating innovative solutions for manufacturing and detailing is pushing the lightweight structures market, a strategy adopted by a UK based company, I2O ltd who design and manufacture bespoke innovative tensile structures. The company held a competition for an innovative, scalable design to complement their product range. The competition was open to all schools, students, sports clubs, restaurants, golf clubs and theme parks and resulted in many entries designed by both school children and adults. The winning design is from Priory Park Infant School in St Neots, UK. The so-called tree-like design is inspired by the school tree emblem and its forest school status. The structure will replace the loss of the school’s horse chestnut tree providing shaded creative space for outdoor learning activities. The design challenges for this project derives from two main aspects: I: Transforming the free organic form of trees found in nature into a form that follows a geometric order proven to be structurally stable under different loading conditions whilst maintaining the visual perception of the inspired design. II. Cost-effective solutions for manufacture and detailing of the structure for market development. The project is designed by Insde2Outside Ltd in the UK, as part of an Innovate UK funded knowledge Transfer partnership with Nottingham University. The project will be manufactured and installed by I2O Ltd who plan to add the structure to its standard products for sale

MULTITEXCO - high performance smart multifunctional technical textiles for tensile structures

In recent years, the textile industry developed a new generation of advanced textile materials for the construction sector designed to address the needs of one of the largest markets for textile products. Examples of the advanced textiles developed include fabrics for the rehabilitation of buildings, geotextiles for the consolidation of a wide range of soil structures and the high performance technical textiles for tensile structures. When combine with innovative sensors the fabrics provide an useful tool for the constant monitoring of the structures and can be used to record the mechanical performance or detect anomalies in the expected use of the structures by measuring applied loads, deformations, operating temperatures or other important parameters. This work highlights recent advances in sensor embedded textiles for structural health monitoring of tensile structures. Attention is paid on ease of application, integration in the textile and the use of established and relatively low cost sensing methodologies. The real innovation lies therefore in transferring these methods to unexplored technological fields for smart textiles such as tensile structures

Evidence for multi-fragmentation and mass shedding of boulders on rubble-pile binary asteroid system (65803) Didymos.

Asteroids smaller than 10 km are thought to be rubble piles formed from the reaccumulation of fragments produced in the catastrophic disruption of parent bodies. Ground-based observations reveal that some of these asteroids are today binary systems, in which a smaller secondary orbits a larger primary asteroid. However, how these asteroids became binary systems remains unclear. Here, we report the analysis of boulders on the surface of the stony asteroid (65803) Didymos and its moonlet, Dimorphos, from data collected by the NASA DART mission. The size-frequency distribution of boulders larger than 5 m on Dimorphos and larger than 22.8 m on Didymos confirms that both asteroids are piles of fragments produced in the catastrophic disruption of their progenitors. Dimorphos boulders smaller than 5 m have size best-fit by a Weibull distribution, which we attribute to a multi-phase fragmentation process either occurring during coalescence or during surface evolution. The density per km2 of Dimorphos boulders ≥1 m is 2.3x with respect to the one obtained for (101955) Bennu, while it is 3.0x with respect to (162173) Ryugu. Such values increase once Dimorphos boulders ≥5 m are compared with Bennu (3.5x), Ryugu (3.9x) and (25143) Itokawa (5.1x). This is of interest in the context of asteroid studies because it means that contrarily to the single bodies visited so far, binary systems might be affected by subsequential fragmentation processes that largely increase their block density per km2. Direct comparison between the surface distribution and shapes of the boulders on Didymos and Dimorphos suggest that the latter inherited its material from the former. This finding supports the hypothesis that some asteroid binary systems form through the spin up and mass shedding of a fraction of the primary asteroid

Fast boulder fracturing by thermal fatigue detected on stony asteroids.

Spacecraft observations revealed that rocks on carbonaceous asteroids, which constitute the most numerous class by composition, can develop millimeter-to-meter-scale fractures due to thermal stresses. However, signatures of this process on the second-most populous group of asteroids, the S-complex, have been poorly constrained. Here, we report observations of boulders' fractures on Dimorphos, which is the moonlet of the S-complex asteroid (65803) Didymos, the target of NASA's Double Asteroid Redirection Test (DART) planetary defense mission. We show that the size-frequency distribution and orientation of the mapped fractures are consistent with formation through thermal fatigue. The fractures' preferential orientation supports that these have originated in situ on Dimorphos boulders and not on Didymos boulders later transferred to Dimorphos. Based on our model of the fracture propagation, we propose that thermal fatigue on rocks exposed on the surface of S-type asteroids can form shallow, horizontally propagating fractures in much shorter timescales (100 kyr) than in the direction normal to the boulder surface (order of Myrs). The presence of boulder fields affected by thermal fracturing on near-Earth asteroid surfaces may contribute to an enhancement in the ejected mass and momentum from kinetic impactors when deflecting asteroids

Change & Maintaining Change in School Cafeterias: Economic and Behavioral-Economic Approaches to Increasing Fruit and Vegetable Consumption

Developing a daily habit of consuming fruits and vegetables (FV) in children is an important public-health goal. Eating habits acquired in childhood are predictive of adolescent and adult dietary patterns. Thus, healthy eating patterns developed early in life can protect the individual against a number of costly health deficits and may reduce the prevalence of obesity. At present, children in the United States (US) under-consume FV despite having access to them through the National School Lunch Program. Because access is an obstacle to developing healthy eating habits, particularly in low-income households, targeting children’s FV consumption in schools has the advantage of near-universal FV availability among more than 30 million US children. This chapter reviews economic and behavioral-economic approaches to increasing FV consumption in schools. Inclusion criteria include objective measurement of FV consumption (e.g., plate waste measures) and minimal demand characteristics. Simple but effective interventions include (a) increasing the variety of vegetables served, (b) serving sliced instead of whole fruits, (c) scheduling lunch after recess, and (d) giving children at least 25 minutes to eat. Improving the taste of FV and short-term incentivizing consumption of gradually increasing amounts can produce large increases in consumption of these foods. Low-cost game-based incentive program may increase the practicality of the latter strategy

Achievement of the planetary defense investigations of the Double Asteroid Redirection Test (DART) mission

NASA's Double Asteroid Redirection Test (DART) mission was the first to demonstrate asteroid deflection, and the mission's Level 1 requirements guided its planetary defense investigations. Here, we summarize DART's achievement of those requirements. On 2022 September 26, the DART spacecraft impacted Dimorphos, the secondary member of the Didymos near-Earth asteroid binary system, demonstrating an autonomously navigated kinetic impact into an asteroid with limited prior knowledge for planetary defense. Months of subsequent Earth-based observations showed that the binary orbital period was changed by –33.24 minutes, with two independent analysis methods each reporting a 1σ uncertainty of 1.4 s. Dynamical models determined that the momentum enhancement factor, β, resulting from DART's kinetic impact test is between 2.4 and 4.9, depending on the mass of Dimorphos, which remains the largest source of uncertainty. Over five dozen telescopes across the globe and in space, along with the Light Italian CubeSat for Imaging of Asteroids, have contributed to DART's investigations. These combined investigations have addressed topics related to the ejecta, dynamics, impact event, and properties of both asteroids in the binary system. A year following DART's successful impact into Dimorphos, the mission has achieved its planetary defense requirements, although work to further understand DART's kinetic impact test and the Didymos system will continue. In particular, ESA's Hera mission is planned to perform extensive measurements in 2027 during its rendezvous with the Didymos–Dimorphos system, building on DART to advance our knowledge and continue the ongoing international collaboration for planetary defense

Interaction between fiber-glass profiles and membranes for building active tensile structures

Studio dell'utilizzo di materiali con particolare comportamento elastico come elementi che possano tensionare il tessuto di tensostrutture o strutture temporanee in generale. Il testo descrive anche test sperimentali e la costruzione di un prototipo con il principio esposto

Design of a cost effective small span tensile roof

Tensile Structures offer a wide variety of membrane forms however, due to the interdependence of form and structural behaviour, only few forms have so far been built. The increasing need for building new tensile forms and investigating innovative solutions for manufacturing and detailing is pushing the lightweight structures market, a strategy adopted by a UK based company, I2O ltd who design and manufacture bespoke innovative tensile structures. The company held a competition for an innovative, scalable design to complement their product range. The competition was open to all schools, students, sports clubs, restaurants, golf clubs and theme parks and resulted in many entries designed by both school children and adults. The winning design is from Priory Park Infant School in St Neots, UK. The so-called tree-like design is inspired by the school tree emblem and its forest school status. The structure will replace the loss of the school’s horse chestnut tree providing shaded creative space for outdoor learning activities. The design challenges for this project derives from two main aspects: I: Transforming the free organic form of trees found in nature into a form that follows a geometric order proven to be structurally stable under different loading conditions whilst maintaining the visual perception of the inspired design. II. Cost-effective solutions for manufacture and detailing of the structure for market development. The project is designed by Insde2Outside Ltd in the UK, as part of an Innovate UK funded knowledge Transfer partnership with Nottingham University. The project will be manufactured and installed by I2O Ltd who plan to add the structure to its standard products for sale