Jensen W.A.,Gore and Associates Inc. |
Kowalski S.M.,Minitab Inc.
Quality Engineering | Year: 2012
This case study is from an experiment done on a step of a manufacturing process. The objective of the experiment is to determine the appropriate levels of three factors to optimize two responses in order to ensure that the manufactured product meets customer requirements. The experiment performed is more complex than standard experimental designs because it has aspects of response surface, blocking, and split-plot elements that pose unique analysis challenges. These challenges include determination of the appropriate error term for significance testing and checking of model assumptions. We illustrate the correct analysis including the residual analysis and multiple response optimization. Copyright © Taylor & Francis Group, LLC. Source
Rhodes J.F.,Childrens Heart Institute |
Goble J.,Gore and Associates Inc.
Catheterization and Cardiovascular Interventions | Year: 2014
Objectives Our goal was to summarize the outcome for all subjects evaluated during a prospective clinical study in the United States with the GORE® HELEX® Septal Occluder for transcatheter repair of secundum atrial septal defects (ASD). Background The GORE® HELEX® Septal Occluder is currently utilized for repair of secundum ASD. No previous reports are available that summarize the combined clinical trial outcomes for this device. Methods In the United States between 1999 and 2009, 435 subjects were enrolled through the Feasibility, Pivotal, Continued Access, and Post-Approval Studies. All subjects enrolled through these studies were collectively reviewed as the "study cohort." Clinical success, defined as a composite evaluation of safety and efficacy, is reported for subjects at the 12-month follow-up period. Results Of the 435 device subjects enrolled in the four clinical studies, 412 subjects were eligible for follow-up. Device efficacy, as represented by clinical closure at 12 months, was achieved in 98.3% of subjects, and in 99.5% of those receiving a device whose nominal diameter was greater or equal to twice the balloon sized defect diameter. Through 12 months following implantation, freedom from major adverse events was 95.2%. Together, these results yield a 93.0% composite clinical success at 12 months following the index procedure. Conclusions The combined clinical study cohort represents the largest prospective, controlled clinical trial data set available for the GORE® HELEX® Septal Occluder. The clinical data presented in this report reaffirm the safety and efficacy of the GORE® HELEX® Septal Occluder when utilized for secundum atrial septal defect repair. © 2013 Wiley Periodicals, Inc. Source
Els L.,Consulto Enviro CC |
Fereday F.,Gore and Associates Inc. |
Vorster O.,Resonant Environmental Pty Ltd
Proceedings of the 12th International Ferroalloys Congress: Sustainable Future | Year: 2010
Chelyabinsk Electrometallurgical Kombinant (ChEMK) replaced the existing wet scrubbing system at their Chelyabinsk plant with a dry system using a baghouse filter. The objectives of the new ventilation system are as follows: Capture the fume and heat evolved in the furnace hooding effectively Filter the particulate from the gas stream and minimize emissions to the atmosphere Minimize energy usage and maintenance expenses The paper explains the methods used to achieve these objectives. Previously, Furnaces 45 to 48 were partially enclosed with the central feed area of each furnace venting to a stack, while the outer section of the furnace was enclosed and extracted by a scrubber. New gas cleaning systems were installed at furnaces 45 to 48 to ensure adequate extraction from the furnaces and eliminate atmospheric emissions. Prior to system design field testing was performed and an off gas model was developed to predict heat generation under future conditions with various combinations of reducing agents. The model predicts the gas temperature rise through the hood based on the gas flow drawn into the furnace hood. The ratio of heat in the furnace off gas to the furnace power input is developed based on the charge mix constituents. The hood volume was selected as the most appropriate to minimize the baghouse size, but still provide a high enough hood face velocity to keep the fume inside the hood. Various gas cooling methods were evaluated with a radiant/convective (trombone) cooler being selected so the outlet gas temperature does not exceed the limitations of the downstream equipment and filter bags. The baghouse type and filter media were selected to maximize the filter velocity while assuring long bag life and minimizing operating maintenance expenses. The filter media was selected based on improved cleaning ability of membrane filter media and to minimize system energy consumption and to particulate emissions. Operating field results are reported. Source