Pub Date : 2009-04-07DOI: 10.17764/JIET.52.1.Q03J8KHR5G4K58Q4
T. Joyce, Oonagh Gaffney, S. Kher, Simon P. Wilson
This study describes the production sampling environmental stress test (PSEST) process and the offline analysis conducted. Some of the key characteristics and parameters of the test are outlined. The analytical process is based on two types of regression model, each of which links a dependent variable (the log of time to failure in each dwell, or the log of the number failed in each dwell) to independent variables such as temperature and age. These two types of regression are known as Weibull regression1 and Poisson regression.2 Using the estimated regression coefficients, expressions for the probability distribution of a unit under test can be written and used to optimize the test duration.
{"title":"Modeling and Adapting Production Environmental Stress Testing","authors":"T. Joyce, Oonagh Gaffney, S. Kher, Simon P. Wilson","doi":"10.17764/JIET.52.1.Q03J8KHR5G4K58Q4","DOIUrl":"https://doi.org/10.17764/JIET.52.1.Q03J8KHR5G4K58Q4","url":null,"abstract":"This study describes the production sampling environmental stress test (PSEST) process and the offline analysis conducted. Some of the key characteristics and parameters of the test are outlined. The analytical process is based on two types of regression model, each of which links a dependent variable (the log of time to failure in each dwell, or the log of the number failed in each dwell) to independent variables such as temperature and age. These two types of regression are known as Weibull regression1 and Poisson regression.2 Using the estimated regression coefficients, expressions for the probability distribution of a unit under test can be written and used to optimize the test duration.","PeriodicalId":35935,"journal":{"name":"Journal of the IEST","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67803684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-04-07DOI: 10.17764/JIET.52.1.8U25474R4W871265
G. Knoth, D. Jackson, N. Sorbo
Many advanced assemblies require high-volume and cost-effective selective cleaning during various stages of assembly or rework operations. Due to component compatibility problems and drying challenges, partially assembled devices cannot be immersed in or sprayed with aqueous cleaners or solvents. Newer dry cleaning techniques such as carbon dioxide (CO2) aerosol spray cleaning processes (snow cleaning) have proven to be challenging to implement in automated high-volume manufacturing operations. Issues associated with conventional snow cleaning include high costs of operation, lack of process consistency, ineffective controls, and the requirements for a supply of high-purity liquid CO2.Advanced CO2 composite spray [CO2(solid)-compressed dry air (CDA)(gas)] cleaning is an effective alternative to traditional spray and immersion cleaning processes and to conventional snow cleaning for selectively removing contaminants and films from partially assembled hard disk drive (HDD) components during the remanufactur...
{"title":"Automated CO2 Composite Spray Cleaning System for HDD Rework Parts","authors":"G. Knoth, D. Jackson, N. Sorbo","doi":"10.17764/JIET.52.1.8U25474R4W871265","DOIUrl":"https://doi.org/10.17764/JIET.52.1.8U25474R4W871265","url":null,"abstract":"Many advanced assemblies require high-volume and cost-effective selective cleaning during various stages of assembly or rework operations. Due to component compatibility problems and drying challenges, partially assembled devices cannot be immersed in or sprayed with aqueous cleaners or solvents. Newer dry cleaning techniques such as carbon dioxide (CO2) aerosol spray cleaning processes (snow cleaning) have proven to be challenging to implement in automated high-volume manufacturing operations. Issues associated with conventional snow cleaning include high costs of operation, lack of process consistency, ineffective controls, and the requirements for a supply of high-purity liquid CO2.Advanced CO2 composite spray [CO2(solid)-compressed dry air (CDA)(gas)] cleaning is an effective alternative to traditional spray and immersion cleaning processes and to conventional snow cleaning for selectively removing contaminants and films from partially assembled hard disk drive (HDD) components during the remanufactur...","PeriodicalId":35935,"journal":{"name":"Journal of the IEST","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2009-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67803558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-10-20DOI: 10.17764/JIET.51.2.Q2J44626WMP45L70
O. Valet, M. Lankers
The sources of particulate contamination are often not easy to identify. To control manufacturing processes, the measurement of particle concentration and size is necessary and has been routinely performed for many years. Technology has been developed to increase the information available for the immediate evaluation of particles. The method analyzes airborne particles or particles isolated from liquids automatically according to their number, size, and chemical composition.1,2 The analysis of thousands of particles enables users to locate the major sources of contamination in various manufacturing processes.The analytical tool provides rapid determination of particulate contamination, thus allowing for a quick, efficient response. Over time, the ability to compare analytical result data sets assists in detecting trends and implementing the appropriate quality management. Routine use of the technology contributes to ongoing supervision and optimization of production processes.This study reports on the use...
{"title":"Higher Yield and Quality through Particle Identification","authors":"O. Valet, M. Lankers","doi":"10.17764/JIET.51.2.Q2J44626WMP45L70","DOIUrl":"https://doi.org/10.17764/JIET.51.2.Q2J44626WMP45L70","url":null,"abstract":"The sources of particulate contamination are often not easy to identify. To control manufacturing processes, the measurement of particle concentration and size is necessary and has been routinely performed for many years. Technology has been developed to increase the information available for the immediate evaluation of particles. The method analyzes airborne particles or particles isolated from liquids automatically according to their number, size, and chemical composition.1,2 The analysis of thousands of particles enables users to locate the major sources of contamination in various manufacturing processes.The analytical tool provides rapid determination of particulate contamination, thus allowing for a quick, efficient response. Over time, the ability to compare analytical result data sets assists in detecting trends and implementing the appropriate quality management. Routine use of the technology contributes to ongoing supervision and optimization of production processes.This study reports on the use...","PeriodicalId":35935,"journal":{"name":"Journal of the IEST","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67803285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-10-20DOI: 10.17764/JIET.51.2.G751061R06T68867
C. Lam, Huairui Guo
The long-term performance prediction of optical products deployed outdoors is important. The accuracy of the prediction directly affects warranty cost calculations. In indoor environments, products are generally operated under controlled temperature and humidity. However, products outdoors usually experience multiple stresses that continuously vary with time. An outdoor-use optical product, such as a fiber distribution hub cabinet with splitters, connectors, and fan-outs built in, will experience temperature cycling effects and varying humidity. Therefore, time-varying temperature and humidity are considered as major stresses acting on outdoor-use optical products. This study proposes a practical method that uses design of experiment (DOE) techniques and generalized log-linear (GLL) life-stress relationship to predict the life of outdoor optical products. The proposed method can consider the cumulative damage caused by time-varying temperature and humidity and was applied to predict the warranty return of...
{"title":"Accelerated Life Test Modeling of Outdoor Optical Products with Time-Varying Multi-Stresses","authors":"C. Lam, Huairui Guo","doi":"10.17764/JIET.51.2.G751061R06T68867","DOIUrl":"https://doi.org/10.17764/JIET.51.2.G751061R06T68867","url":null,"abstract":"The long-term performance prediction of optical products deployed outdoors is important. The accuracy of the prediction directly affects warranty cost calculations. In indoor environments, products are generally operated under controlled temperature and humidity. However, products outdoors usually experience multiple stresses that continuously vary with time. An outdoor-use optical product, such as a fiber distribution hub cabinet with splitters, connectors, and fan-outs built in, will experience temperature cycling effects and varying humidity. Therefore, time-varying temperature and humidity are considered as major stresses acting on outdoor-use optical products. This study proposes a practical method that uses design of experiment (DOE) techniques and generalized log-linear (GLL) life-stress relationship to predict the life of outdoor optical products. The proposed method can consider the cumulative damage caused by time-varying temperature and humidity and was applied to predict the warranty return of...","PeriodicalId":35935,"journal":{"name":"Journal of the IEST","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67803541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-10-20DOI: 10.17764/JIET.51.2.QW566212T4H8J660
T. W. Hoy, J. Herrmann
Useful system endurance tests require operating a system in settings similar to operational environments. However, existing test facilities may not be good replicas of the operational environment, especially for systems with long life cycles that are being used in new and unforeseen situations. Because constructing new test facilities can be expensive and time-consuming, it is desirable to use the existing test infrastructure to replicate the operational environment as closely as possible. This study presents an optimization model that determines the most appropriate amount of testing to conduct using each existing test facility. A multi-objective model is also presented, and the application of this work to two military vehicle tests is discussed.
{"title":"Optimal Utilization of Test Facilities to Replicate Operational Environments","authors":"T. W. Hoy, J. Herrmann","doi":"10.17764/JIET.51.2.QW566212T4H8J660","DOIUrl":"https://doi.org/10.17764/JIET.51.2.QW566212T4H8J660","url":null,"abstract":"Useful system endurance tests require operating a system in settings similar to operational environments. However, existing test facilities may not be good replicas of the operational environment, especially for systems with long life cycles that are being used in new and unforeseen situations. Because constructing new test facilities can be expensive and time-consuming, it is desirable to use the existing test infrastructure to replicate the operational environment as closely as possible. This study presents an optimization model that determines the most appropriate amount of testing to conduct using each existing test facility. A multi-objective model is also presented, and the application of this work to two military vehicle tests is discussed.","PeriodicalId":35935,"journal":{"name":"Journal of the IEST","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67803422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-10-20DOI: 10.17764/JIET.51.2.G124437844147021
A. Dixon, D. Ensor, Roberta Burrows
IEST has again taken a leadership role in ISO Technical Committee 209 Cleanrooms and associated controlled environments as the committee begins developing standards for the nanoscale.
{"title":"IEST leads ISO 14644 Experts in Focus on Nanotechnology in Cleanrooms","authors":"A. Dixon, D. Ensor, Roberta Burrows","doi":"10.17764/JIET.51.2.G124437844147021","DOIUrl":"https://doi.org/10.17764/JIET.51.2.G124437844147021","url":null,"abstract":"IEST has again taken a leadership role in ISO Technical Committee 209 Cleanrooms and associated controlled environments as the committee begins developing standards for the nanoscale.","PeriodicalId":35935,"journal":{"name":"Journal of the IEST","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67803492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-10-20DOI: 10.17764/JIET.51.2.G8H176K5411J8421
Richard Heine, D. Barker
The desire for enhanced functionality of Army vehicle systems has resulted in increasingly complex systems. This drive is in direct contention with another Army goal of improved reliability. Health and usage monitoring systems (HUMS) and remaining-life prognostics are being developed to address these conflicting goals. One of the major challenges of applying a HUMS to an Army wheeled vehicle system is that the development and per unit cost of the HUMS needs to be relatively low in comparison with typical high-cost applications such as aircraft. Simplified algorithms that derive terrain exposure from a basic set of sensors and estimate fatigue damage accumulated on components where loading comes primarily from terrain have been developed to meet this need. Various inputs and statistical parameters are evaluated for this model based on accuracy of terrain identification and quality of fatigue prediction on an example component. The generalized process and recommendations for application of this model to mil...
{"title":"Health and Usage Monitoring Algorithm Based on Terrain Identification for Mechanical Components on an Army Ground Vehicle System","authors":"Richard Heine, D. Barker","doi":"10.17764/JIET.51.2.G8H176K5411J8421","DOIUrl":"https://doi.org/10.17764/JIET.51.2.G8H176K5411J8421","url":null,"abstract":"The desire for enhanced functionality of Army vehicle systems has resulted in increasingly complex systems. This drive is in direct contention with another Army goal of improved reliability. Health and usage monitoring systems (HUMS) and remaining-life prognostics are being developed to address these conflicting goals. One of the major challenges of applying a HUMS to an Army wheeled vehicle system is that the development and per unit cost of the HUMS needs to be relatively low in comparison with typical high-cost applications such as aircraft. Simplified algorithms that derive terrain exposure from a basic set of sensors and estimate fatigue damage accumulated on components where loading comes primarily from terrain have been developed to meet this need. Various inputs and statistical parameters are evaluated for this model based on accuracy of terrain identification and quality of fatigue prediction on an example component. The generalized process and recommendations for application of this model to mil...","PeriodicalId":35935,"journal":{"name":"Journal of the IEST","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67803234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-04-14DOI: 10.17764/JIET.51.1.3R4M756413461114
P. Hansen, J. Townsend, R. J. Hedgeland
Over the past two decades, the Hubble Space Telescope (HST) contamination control program has evolved from a ground-based integration program to a space-based science-sustaining program. On-orbit, the primary contamination requirement for the telescope was maintaining a low contamination flux in the optical path of the instrument. In addition, to maintain the scientific capability of the telescope, the contamination requirements and specific contamination controls from the second- and third-generation scientific instruments and orbital replacement units were captured within the HST contamination control program. Contamination controls involving the Orbiter, astronauts, and mission were developed for on-orbit operations and four servicing missions. Long-term on-orbit scientific data has shown that these contamination controls successfully protected the HST from contamination.
{"title":"Overview of the HST Contamination Engineering Program at 15 Years: A Cleanliness Metric for Success with Optical Satellites","authors":"P. Hansen, J. Townsend, R. J. Hedgeland","doi":"10.17764/JIET.51.1.3R4M756413461114","DOIUrl":"https://doi.org/10.17764/JIET.51.1.3R4M756413461114","url":null,"abstract":"Over the past two decades, the Hubble Space Telescope (HST) contamination control program has evolved from a ground-based integration program to a space-based science-sustaining program. On-orbit, the primary contamination requirement for the telescope was maintaining a low contamination flux in the optical path of the instrument. In addition, to maintain the scientific capability of the telescope, the contamination requirements and specific contamination controls from the second- and third-generation scientific instruments and orbital replacement units were captured within the HST contamination control program. Contamination controls involving the Orbiter, astronauts, and mission were developed for on-orbit operations and four servicing missions. Long-term on-orbit scientific data has shown that these contamination controls successfully protected the HST from contamination.","PeriodicalId":35935,"journal":{"name":"Journal of the IEST","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67801528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-04-14DOI: 10.17764/JIET.51.1.AXR1237J54476706
C. Collet, P. Chabin, H. Grzeskowiak
In recent years, the phenomena occurring during shock wave propagation in spatial structures have been studied to characterize more accurately and to minimize the effects of pyrotechnical sources. As part of a program managed by the Centre National d'Etudes Spatiales (CNES, the French space agency), SNPE Materiaux Energetiques (SME) and MBDA France collaborated in a study to understand the mechanisms of shock wave propagation induced by the detonation of a linear pyrotechnical source. The focus of the study was on structures representative of space launcher structures such as those used for the Ariane 5 launcher. Various experiments were performed with metallic and composite plates, and two types of measurement devices (strain gauges and accelerometers) were investigated. Additional out-of-plane velocity and displacement measurements were provided by laser vibrometers, and displays of the separation of the plates were provided by a high-speed camera (up to 4800 feet/second). Signals treatment provided ben...
{"title":"Experimental Contribution to the Modeling of Shock Propagation Induced by a Linear Pyrotechnical Source","authors":"C. Collet, P. Chabin, H. Grzeskowiak","doi":"10.17764/JIET.51.1.AXR1237J54476706","DOIUrl":"https://doi.org/10.17764/JIET.51.1.AXR1237J54476706","url":null,"abstract":"In recent years, the phenomena occurring during shock wave propagation in spatial structures have been studied to characterize more accurately and to minimize the effects of pyrotechnical sources. As part of a program managed by the Centre National d'Etudes Spatiales (CNES, the French space agency), SNPE Materiaux Energetiques (SME) and MBDA France collaborated in a study to understand the mechanisms of shock wave propagation induced by the detonation of a linear pyrotechnical source. The focus of the study was on structures representative of space launcher structures such as those used for the Ariane 5 launcher. Various experiments were performed with metallic and composite plates, and two types of measurement devices (strain gauges and accelerometers) were investigated. Additional out-of-plane velocity and displacement measurements were provided by laser vibrometers, and displays of the separation of the plates were provided by a high-speed camera (up to 4800 feet/second). Signals treatment provided ben...","PeriodicalId":35935,"journal":{"name":"Journal of the IEST","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67802408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2008-04-14DOI: 10.17764/JIET.51.1.J2U080889430P003
Diana Granitto
By 1958, the nascent environmental engineering profession had moved from wartime activities into the space age, and this journal began documenting the evolution of an industry. Over the past five decades and under as many titles, the Journal has witnessed advances into contamination control, ecological sciences, and nanotechnology, to name a few.
{"title":"Forging New Frontiers","authors":"Diana Granitto","doi":"10.17764/JIET.51.1.J2U080889430P003","DOIUrl":"https://doi.org/10.17764/JIET.51.1.J2U080889430P003","url":null,"abstract":"By 1958, the nascent environmental engineering profession had moved from wartime activities into the space age, and this journal began documenting the evolution of an industry. Over the past five decades and under as many titles, the Journal has witnessed advances into contamination control, ecological sciences, and nanotechnology, to name a few.","PeriodicalId":35935,"journal":{"name":"Journal of the IEST","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67802489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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