Search

To accomplish lean manufacturing of steel parts, companies should consider potential cost savings throughout the entire manufacturing chain--including steelmaking, forging and casting, machining, and heat treatment. As one approach, the [...]

An alternative method for the hardening of steel parts has been developed as a means of providing steel products with superior mechanical properties through development of high residual compressive stresses on the part surface, and involves the application of intensive quenching during heat treatment. This processing method, termed 'Intensive Quenching,' imparts high residual compressive stresses on the steel surface, thus allowing for the use of lower alloy steels, reduction or elimination of the need for carburization and shot peening, and providing for more cost-effective heat treating. Intensive quenching also provides additional environmental benefits, as the process uses plain water as the quenching media in contrast to traditional heat treatment practices which typically employ hazardous and environmentally unfriendly quenching oil. This paper presents an overview of the theory and application of intensive quenching, as well as provides experimental and computational data obtained for a variety of steel products. Also presented will be results of computer simulations of temperature, structural and stress/strain conditions for a typical pressure vessel during intensive quenching. [DOI: 10.1115/1.1556858]

Objective: To assess whether a surgeon's level of training is associated with outcomes in pediatric tonsillectomy. Design: A retrospective cohort study of the outcomes of pediatric tonsillectomies performed between 2006 and 2016 by senior surgeons versus resident surgeons under the supervision of senior surgeons. Setting: An otolaryngology department in a tertiary academic hospital. Patients: Children younger than 18 years who underwent bilateral tonsillectomy with or without adenoidectomy. Main outcome measures: Intraoperative bleeding, initiation of oral intake, and intraoperative and postoperative complications. Results: Of 785 children, 397 (50.5%) were operated on by a resident surgeon and 388 (49.5%) by a senior surgeon. Patient demographics and surgical techniques were similar between the groups. The mean surgical time was 33.2 minutes in the residents' group and 27.1 minutes in the seniors' group (P =.032). The groups were similar in intraoperative bleeding, while same-day initiation of oral intake was 71% for children in the residents' group versus 61% in the seniors' group (P =.28). Reports of postoperative bleeding necessitating readmission and revised operations were similar for both groups (3.0% and 0.7%, respectively, in the residents' group; and 2.5% and 1.0%, respectively, in the seniors' group). Conclusion: Children undergoing tonsillectomy showed similar short-term outcomes, whether the operations were performed by a senior surgeon or a resident surgeon supervised by an attending surgeon. This study demonstrates the safety of pediatric tonsillectomy performed by resident surgeons supervised by attending physicians. [ABSTRACT FROM AUTHOR]