Origins of elastic properties in ordered nanocomposites

We predict a diblock copolymer melt in the lamellar phase with added spherical nanoparticles that have an affinity for one block to have a lower tensile modulus than a pure diblock copolymer system. This weakening is due to the swelling of the lamellar domain by nanoparticles and the displacement of polymer by elastically inert fillers. Despite the overall decrease in the tensile modulus of a polydomain sample, the shear modulus for a single domain increases dramatically

Suggesting Cooking Recipes Through Simulation and Bayesian Optimization

Cooking typically involves a plethora of decisions about ingredients and tools that need to be chosen in order to write a good cooking recipe. Cooking can be modelled in an optimization framework, as it involves a search space of ingredients, kitchen tools, cooking times or temperatures. If we model as an objective function the quality of the recipe, several problems arise. No analytical expression can model all the recipes, so no gradients are available. The objective function is subjective, in other words, it contains noise. Moreover, evaluations are expensive both in time and human resources. Bayesian Optimization (BO) emerges as an ideal methodology to tackle problems with these characteristics. In this paper, we propose a methodology to suggest recipe recommendations based on a Machine Learning (ML) model that fits real and simulated data and BO. We provide empirical evidence with two experiments that support the adequacy of the methodology

Performance, lean meat proportion and behaviour of fattening pigs given a liquid diet at different animal/feeding-place ratios

Sensor feeding is a liquid feeding system for fattening pigs that is operated with a restricted animal/feeding-place ratio (AFR). The aim of the present study was to quantify the effect of three different AFRs (4:1, 7:1 and 13:1, calculated with a feeding space of 33 cm per animal) on the performance and behaviour of fattening pigs (mean initial weight 26·3 (s.d. 3·3) kg, live weight at slaughter 102 (s.d. 5) kg). The pigs were housed in groups of 40 and each AFR was tested with seven groups (21 groups in total). The daily weight gain of the individual pigs was calculated from the beginning of the experiments until slaughter. Additionally, the lean meat percentage was recorded (AutoFOM). Feeding behaviour was observed by means of 24-h video recording at the ages of 14 and 17 weeks with scan sampling every 5 min. The daily weight gain decreased with increasing AFR ( P<0·01) and females had lower weight gains than barrows ( P<0·001). The lean meat proportion was influenced by the AFR ( P<0·01) and sex of the pigs ( P<0·001). Proportions were highest with the AFR 13:1 and in females. The average number of pigs feeding simultaneously was highest for the AFR of 4:1 ( P<0·01). Moreover, the ingestion rate per day (kg/min) increased with increasing AFR ( P<0·05). The average number of pigs waiting behind other pigs feeding at the trough was highest with the AFR 13:1 ( P<0·001).In conclusion, growth performance and pig behaviour were negatively affected by an AFR of 13:1, which cannot be recommended for use with this feeding system. With an AFR of 4:1 lean meat values were lo

Experiments on Column Base Stiffness of Long-Span Cold-Formed Steel Portal Frames Composed of Double Channels

Cold-formed steel haunched portal frames are popular structures in industrial and housing applications. They are mostly used as sheds, garages, and shelters, and are common in rural areas. Cold-formed steel portal frames with spans of up to 30m (100 ft) are now being constructed in Australia. As these large structures are fairly new to the market, there is limited data on their feasibility and design recommendations. An experimental program was carried out on a series of portal frame systems composed of back-to-back channels for the columns, rafters, and knee braces. The system consisted of three frames connected in parallel with purlins to simulate a free standing structure, with an approximate span of 14 m (46 ft), column height of 5.3 m (17 ft), and apex height of 7 m (23 ft). Several configurations were tested including variations in the knee connection, sleeve stiffeners in the columns and rafters, and loading of either vertical or combined horizontal and vertical loads. Deflections were recorded at various locations to measure global and local movements of the structural members, as well as column base reactions and base rotations. It was determined that the column bases are semi-rigid and further column base connection tests were completed to quantify column base connection stiffness for bending about the column major and minor axes, as well as twist. Results of the column base connection stiffness are presented as well as the implications for frame design

Superconductivity-enhanced bias spectroscopy in carbon nanotube quantum dots

We study low-temperature transport through carbon nanotube quantum dots in the Coulomb blockade regime coupled to niobium-based superconducting leads. We observe pronounced conductance peaks at finite source-drain bias, which we ascribe to elastic and inelastic cotunneling processes enhanced by the coherence peaks in the density of states of the superconducting leads. The inelastic cotunneling lines display a marked dependence on the applied gate voltage which we relate to different tunneling-renormalizations of the two subbands in the nanotube. Finally, we discuss the origin of an especially pronounced sub-gap structure observed in every fourth Coulomb diamond