A Sophisticated Method of the Mechanical Design of Cable Accessories Focusing on Interface Contact Pressure

The most critical positions of a prefabricated cable accessory, from the electrical point of view, are the interfaces between the stress cone and its surroundings. Accordingly, the contact pressure on those interfaces needs to be carefully designed to assure both good dielectric strength and smooth installation of the stress cone. Nevertheless, since stress cones made from rubber are under large deformation after installation, their internal stress distribution is neither practical to measure directly by planting sensors, nor feasible to compute accurately with the conventional theory of linear structural mechanics. This paper presents one sophisticated method for computing the mechanical stress distribution in rubber stress cones of cable accessories by employing hyperelastic models in a computation model based on the finite element method. This method offers accurate results for rubber bodies of complex geometries and large deformations. Based on the method, a case study of a composite prefabricated termination for extruded cables is presented, and the sensitivity analysis is given as well

Study of retinal structure changes after YAG laser ablation in physiological vitreous floaters

AIM: To observe the structure changes of vitreous and retina after YAG laser ablation in patients with physiological vitreous floaters.METHODS: The selected 40 patients of physiological vitreous floaters, before YAG laser ablation, were checked for best corrected visual acuity, non-contact intraocular pressure, took their anterior segment photos, measured their foveola thickness(FT)and retinal nerve fiber layer(RNFL)by OCT. The YAG laser ablation was completed by one experienced surgeon. After the YAG laser ablation, all patients were checked for non-contact intraocular pressure and gave pranoprofen eye drops tid for 3d. At 2d, 1wk, 1 and 3mo after the surgery, they were reviewed for best corrected visual acuity, non-contact intraocular pressure. At 3mo later anterior segment photos were taken. At 1wk, 1 and 3mo after the surgery, FT and RNFL were measured again.RESULTS: The postoperative 2d, 1wk, 1 and 3mo, best corrected visual acuity, non-contact intraocular pressure of the patients had no significant difference with preoperative(P>0.05). The preoperative anterior segment photos showed obvious single or sheet opacity of vitreous, the postoperative 3mo photos showed that vitreous opacities decreased or disappeared, no other abnormal changes were found. The preoperative OCT data showed that FT was 214.60±9.35μm, the postoperative 1wk, 1 and 3mo FT were 213.75±9.07μm, 213.40±8.83μm, 213.85±9.22μm. The preoperative RNFL were upper 130.26±14.23μm, lower 133.15±14.46μm, nasal 82.48±13.50μm, temporal 75.40±11.89μm; The postoperative 1wk RNFL were upper 130.02±14.02μm, lower 132.99±14.05μm, nasal 82.35±13.07μm, temporal 75.42±11.66μm. The postoperative 1mo RNFL were upper 130.28±14.43μm, lower 133.08±13.99μm, nasal 82.31±13.72μm, temporal 75.45±12.03μm. The postoperative 3mo RNFL were upper 130.43±14.30μm, lower 133.22±14.20μm, nasal 82.27±13.11μm, temporal 75.46±11.91μm. The differences of preoperative and postoperative 1wk, 1 and 3mo FT and RNFL had no statistical significance(P>0.05). CONCLUSION: YAG laser ablation has no adverse effects to vitreous and retinal structure in patients with physiological vitreous floaters, it is effective and safe

N-(3-Chloro-4-eth­oxy­benzo­yl)-N′-(2-meth­oxy­phen­yl)thio­urea

In the title compound, C17H17ClN2O3S, the central carbonyl­thio­urea unit is nearly planar [maximum atomic deviation = 0.019 (3) Å] and makes dihedral angles of 2.47 (7) and 17.76 (6)° with the terminal benzene rings. An intra­molecular N—H⋯O hydrogen bond occurs. Weak inter­molecular C—H⋯S and C—H⋯Cl hydrogen bonding is observed in the crystal structure