The temperature dependence of surface tension and density for Fe–Cr–Mo (AISI 4142), Fe–Cr–Ni (AISI 304), and Fe–Cr–Mn–Ni TRIP/TWIP high-manganese (16 wt% Cr, 7 wt% Mn, and 3–9 wt% Ni) liquid alloys are investigated using the conventional maximum bubble pressure (MBP) and sessile drop (SD) methods. In addition, the surface tension of liquid steel is measured using the oscillating droplet method on electromagnetically levitated (EML) liquid droplets at the German Aerospace Centre (DLR, Cologne). The data of thermophysical properties for Fe–Cr–Mn–Ni is of major importance for modeling of infiltration and gas atomization processes in the prototyping of a “TRIP-Matrix-Composite.” The surface tension of TRIP/TWIP steel increased with an increase in temperature in MBP as well as in SD measurement. The manganese evaporation with the conventional measurement methods is not significantly high within the experiments (∆Mₙ < 0.5 %). The temperature coefficient of surface tension (dσ/dT) is positive for liquid steel samples, which can be explained by the concentration of surface active elements. A slight influence of nickel on the surface tension of Fe–Cr–Mn–Ni steel was experimentally observed where σ is decreased with increasing nickel content. EML measurement of high-manganese steel, however, is limited to the undercooling state of the liquid steel. The manganese evaporation strongly increased in excess of the liquidus temperature in levitation measurements and a mass loss of droplet of 5 % was observed.
Willaume, Magali, Rollin, Audrey, and Casagrande, Marion
Regional environmental change, 2014 Feb., v. 14, no. 1, p. 333-345.
farmers, thermal stress, process design, interviews, cropping systems, crop production, water resources, field crops, climate change, climate, temperature, and irrigation
Climate change, particularly increasing temperatures and decreasing and highly variable water availability, will affect temperate field crop production. Beyond expected positive or negative impact assessment, there is a need to explore adaptation options for arable cropping systems. Involvement of farmers in the cropping system design process allows tailoring locally relevant and innovative adaptation options while taking into account interactions between crop management choices. In southwestern France, we devised and applied a participatory methodology of cropping system conception adapted to the climate change context. This method is based on prototyping methods as well as the vulnerability concept, and follows three successive steps: presentation of exposure, assessment of crop sensitivity during individual interviews with farmers, and conception of crop system adaptations during collective workshops. The proposed cropping systems differ according to access to water resources for irrigation of farmers. Non- or hardly irrigating farmers considered their current cropping systems to be already adapted to climate change, and focused on improving their efficiency using already known management practices. They did not feel endangered by the future climate scenario. Irrigating farmers were inclined to substitute sensitive crops or even redesign their cropping systems. Nevertheless, they had difficulty to distance themselves from current cropping choices and economical or technical constraints. Proposed cropping systems were thus not very disruptive compared to current practices. This work can be supplemented through assessments of cropping system sustainability and performance according to water and thermal stress.
Romero Gómez, J., Ferreiro Garcia, R., Carbia Carril, J., and Romero Gómez, M.
Renewable and sustainable energy reviews, 2013 May, v. 21, p. 1-12.
refrigerators, prototypes, refrigeration, cooling, and temperature
Various AMR refrigerators prototypes have been developed with a view to implementing magnetic refrigeration (MR) at room temperature in a short time. This article describes the working mode of the two basic categories into which these can be divided (reciprocating and rotary) and compares them to show the advantages and disadvantages offered. A review of the latest and most significant alternative linear prototypes is carried out, providing design concepts and performance characteristics. Such characteristics include the operating frequency, magnet field type and field strength, regenerator materials and geometry, and maximum temperature span and cooling capacity. Also included is a study carried out by the authors focused on the prototyping of an MR system aimed at avoiding the shortcomings of other prototypes manufactured to date.
Cheesbrough, Vanessa, Rosentrater, Kurt A., and Visser, Jerry
Journal of polymers and the environment, 2008 Jan., v. 16, no. 1, p. 40-50.
bioplastics, biofillers, distilers dried grain with solubles, resin composites, compression, particle size, waste utilization, curing (nonfood products), resins, adhesives, mechanical properties, temperature, mechanical stress, color, water activity, composite polymers, distillers grains, chemical composition, and biopolymers
Includes references Interest in renewable biofuel sources has intensified in recent years, leading to greatly increased production of ethanol and its primary coproduct, Distillers Dried Grain with Solubles (DDGS). Consequently, the development of new outlets for DDGS has become crucial to maintaining the economic viability of the industry. In light of these developments, this preliminary study aimed to determine the suitability of DDGS for use as a biofiller in low-cost composites that could be produced by rapid prototyping applications. The effects of DDGS content, particle size, curing temperature, and compression on resulting properties, such as flexural strength, modulus of elasticity, water activity, and color were evaluated for two adhesive bases. The composites formed with phenolic resin glue were found to be greatly superior to glue in terms of mechanical strength and durability: resin-based composites had maximum fiber stresses of 150-380 kPa, while glue composites had values between 6 kPa and 35 kPa; additionally, glue composites experienced relatively rapid microbial growth. In the resin composites, both decreased particle size and increased compression resulted in increased mechanical strength, while a moderate DDGS content was found to increase flexural strength but decrease Young's modulus. These results indicate that DDGS has the potential to be used in resin glue-based composites to both improve flexural strength and improve potential biodegradability.