31 research outputs found

    Effect of swelling agents on unoriented nylon-6 film-Structural changes

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    93-99<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" calibri;mso-fareast-theme-font:minor-latin;mso-hansi-theme-font:minor-latin;="" mso-bidi-font-family:"times="" new="" roman";color:black;mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">Unoriented nylon-6 films were subjected to aqueous formic acid and benzyl alcohol treatments. Formic acid was found to be more active in causing structural changes. The highest possible formic acid concentration that could be used advantageously was found to be 50% owing to heavy shrinkage at higher concentrations. Solvent-induced crystallization with respect to time of treatment and concentration of solvent revealed entirely different trends<span style="font-size:11.0pt; line-height:115%;font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;="" mso-fareast-font-family:calibri;mso-fareast-theme-font:minor-latin;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" new="" roman";color:#0f0f0f;mso-ansi-language:="" en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">. These treatments give rise to shrinkage of films. WAXD and IR spectroscopy revealed that crystallization results in the formation of a large amount of monoclinic ɑ-crystalline form. Scanning electron micrographs revealed significant changes in surface morphology due to solvent etching.</span

    Training Diverse High-Dimensional Controllers by Scaling Covariance Matrix Adaptation MAP-Annealing

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    Pre-training a diverse set of neural network controllers in simulation has enabled robots to adapt online to damage in robot locomotion tasks. However, finding diverse, high-performing controllers requires expensive network training and extensive tuning of a large number of hyperparameters. On the other hand, Covariance Matrix Adaptation MAP-Annealing (CMA-MAE), an evolution strategies (ES)-based quality diversity algorithm, does not have these limitations and has achieved state-of-the-art performance on standard QD benchmarks. However, CMA-MAE cannot scale to modern neural network controllers due to its quadratic complexity. We leverage efficient approximation methods in ES to propose three new CMA-MAE variants that scale to high dimensions. Our experiments show that the variants outperform ES-based baselines in benchmark robotic locomotion tasks, while being comparable with or exceeding state-of-the-art deep reinforcement learning-based quality diversity algorithms.Comment: Source code and videos available at https://scalingcmamae.github.i

    Is medial calcar continuity necessary in plate osteosynthesis for proximal humerus fractures?

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    WOS: 000427371000018PubMed: 29519987Objective: To evaluate the functional and radiological results of patients with and without medial calcar continuity in plate osteosynthesis applied for a proximal humerus fracture retrospectively. Methods: The study included 27 patients to whom plate osteosynthesis was applied because of a proximal humerus fracture between January 2, 2010, and December 30, 2013, at Okmeydani Research and Training Hospital. Patients were separated into Group A with medial calcar continuity and Group B without medial calcar continuity. On the radiographs taken postoperatively and at the final follow-up examination, measurements were taken of the humeral head height and the humeral neck-shaft angle. The presence of avascular necrosis was recorded. Results: The functional and radiological results of the patients were evaluated after a mean follow-up of 39.1 months. No statistically significant difference was determined between Groups A and B in respect of the postoperative and the final follow-up humeral head height (P > 0.05). No statistically significant difference was determined between Groups A and B in respect of the postoperative and the final follow-up humeral neck-shaft angle (P > 0.05). Plate breakage was seen in one patient without medial calcar continuity. Penetration of the screw into the joint was determined in one patient in Group A and three patients in Group B. No avascular necrosis or infection was seen in any patient. Conclusion: When the surgical process has not damaged the soft tissue and sufficient stability has been achieved, providing calcar continuity is not an absolute condition
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