Chiral phase-coexistence in compressed double-twist elastomers

We adapt the theory of anisotropic rubber elasticity to model cross-linked double-twist liquid crystal cylinders such as exhibited in biological systems. In mechanical extension we recover strain-straightening, but with an...

A generalized tube model of rubber elasticity

A new type of micro-mechanically motivated chain network model for rubber-like materials is proposed. The model demonstrates how the local molecular constraints modify under deformation and shows the impact of these changes on the macroscopic elasticity of the material.

PENGARUH DIAMETER PIRINGAN DAN ELASTISITAS KARET PENGUPAS TERHADAP KINERJA ALAT PENGUPAS LADA TIPE PIRINGAN

To produce while pepper using traditional method, the ripe berries are soaked in a river or a pond for 10-14 days prior to decorticating. To improve the traditional method. Research Institute for Spice and Medicinal Crops has designed pepper decorticator to support the white pepper processing. This decorticator has a good function, hut its performance still need to be improved, as it still produces high percentage of white pepper damage. This experiment was aimed to at improving (he performance of the pepper decorticator. The experiment was conducted from July to Ocktobcr 1999 and divided into two steps i.e. preliminary and main experiment. The treatments applied on Ihe main experiment were (I) disc diameter (18, 20, and 22 cm) and (2) rubber elasticity (5.34, 7.74, 9.79, and 15.02 N/mm). The experiment was designed as a completely randomized, arranged factorially in three replications. The pepper variety used for the experiment was Lampung Daun Lebar. The disc distance of pepper decorticator in this experiment was set at 3.5 cm based on the preliminary experiment. Results showed that the optimal disc diameter and nibber elasticity was 20 cm and 7.74 N/mm respectively. Decorticator performance on the optimal condition were : decorticated pepper 97.25%, white pepper damage as pepper defect 2.46% and as broken pepper 1.98% respectively and the capacity of decorticator was 42.27 kg/hours. In general, the quality of while pepper produced met the National Standard of Indonesia.

Monte Carlo Study of Rubber Elasticity on the Basis of Finsler Geometry Modeling

Configurations of the polymer state in rubbers, such as so-called isotropic (random) and anisotropic (almost aligned) states, are symmetric/asymmetric under space rotations. In this paper, we present numerical data obtained by Monte Carlo simulations of a model for rubber formulations to compare these predictions with the reported experimental stress–strain curves. The model is defined by extending the two-dimensional surface model of Helfrich–Polyakov based on the Finsler geometry description. In the Finsler geometry model, the directional degree of freedom σ → of the polymers and the polymer position r are assumed to be the dynamical variables, and these two variables play an important role in the modeling of rubber elasticity. We find that the simulated stresses τ sim are in good agreement with the reported experimental stresses τ exp for large strains of up to 1200 % . It should be emphasized that the stress–strain curves are directly calculated from the Finsler geometry model Hamiltonian and its partition function, and this technique is in sharp contrast to the standard technique in which affine deformation is assumed. It is also shown that the obtained results are qualitatively consistent with the experimental data as influenced by strain-induced crystallization and the presence of fillers, though the real strain-induced crystallization is a time-dependent phenomenon in general.