Fabrication and transport critical currents of multifilamentary MgB2/Fe wires and tapes

Multifilamentary MgB2/Fe wires and tapes with high transport critical current densities have been fabricated using a straightforward powder-in-tube (PIT) process. After annealing, we measured transport jc values up to 1.1 * 105 A/cm2 at 4.2 K and in a field of 2 T in a MgB2/Fe square wire with 7 filaments fabricated by two-axial rolling, and up to 5 * 104 A/cm2 at 4.2 K in 1 T in a MgB2/Fe tape with 7 filaments. For higher currents these multifilamentary wires and tapes quenched due to insufficient thermal stability of filaments. Both the processing routes and deformation methods were found to be important factors for fabricating multifilamentary MgB2 wires and tapes with high transport jc values.Comment: 13 pages, 7 figure

Simulation Modeling of Particleboard Density Profile

Particleboard properties are affected by the vertical density profile among other factors. To predict or model board properties, one needs to determine the density profile. A simulation model was developed in this study to model the vertical density profile by simulating the hot pressing process of a particleboard. Temperature and moisture content profiles during hot pressing in the thickness direction of a pressed mat and the influential factors affecting wood compressibility were modeled such that they can be determined at any moment of pressing. The models developed allow calculations of the profiles to be carried out by either the finite difference method or an alternative approximation method presented herein. The density profile was modeled based on the compressibility and the resulting strain of each layer of the board thickness due to pressing

Seed germination of three dominant Artemisia species in loess hilly region: alternating temperature, osmotic potential, and light effects

Non-Peer ReviewedIn this study, we evaluated the effects of alternating temperature, osmotic potential and light in the achene germination of three dominant Artemisia species (A. scoparia, A. gmelinii Web. and A. giraldii Pamp.) on arable old land after being abandoned in loess hilly region of Northern Shaanxi, in order to provide information about germination requirements which could be use for conservation studies. Results showed that A. scoparia had wider alternating temperature extremes than two other species and A. giraldii Pamp. and A. gmelinii Web. had lower optimum alternating temperature (25 oC/20 oC) than A. scoparia (30 oC/25 oC). Osmotic potential affected germination of all species significantly, but A. scoparia had better germination results than others in every treatment. In light treatments, although A. giraldii Pamp. and A. gmelinii Web. had lower germination proportion in white light, they had bigger germination proportion in darkness than A. scoparia

Modeling of Strength Properties of Structural Particleboard

The strength properties of structural particleboard are critically important factors. In designing a particular particleboard, a series of experiments can be run to determine the effect of a particular combination of factors. Modeling could be used as an alternative approach. Simulation modeling is one of the modeling techniques that can be fast and cost-effective. Structural particleboard was modeled in this study as a multilayer system that consists of a number of thin and uniform layers that exhibit different strength properties between layers, but the same properties within each layer. The effective modulus of elasticity of a board is a resultant of the combined effect of the modulus of all the layers. The modulus of rupture was obtained by determining the ultimate force or maximum moment during the simulated bending test. Internal bond strength was modeled using a modified regression equation