The annual audit plan of the Office of the Inspector General (OIG) of the Nuclear Regulatory Commission (NRC), which was issued in November 2020, included an audit of the NRC’s practice of allowing “drop-in” visits. These are closed meetings of senior executives of licensees and NRC management. NRC procedures assume that “drop-in” visits do not concern any matters that are related to pending regulatory decisions that could affect the interests of those licensees. The audit objective was to determine whether NRC policies and procedures for non-public interactions with industry stakeholders are adequate to prevent compromise of the independence of agency staff or the appearance of conflicts of interest. The results of this audit were issued in August 2022. In 2017, the OIG conducted another audit [USNRC, OIG-17-A-23, “Audit of NRC's 10 CFR 2.206 Petition Review Process,” August 22, 2017, ADAMS No. ML17234A561] that focused on the public’s trust and confidence in the NRC. That audit examined the procedure that the NRC staff used to evaluate 10 CFR §2.206 enforcement petitions. The OIG found that the NRC staff had not issued a single enforcement order, as the result of 38 enforcement petitions that it had received in the prior three fiscal years, ending in 2016. The OIG concluded that the lack of such actions could adversely affect the public’s perspective on the effectiveness of the agency’s 10 CFR 2.206 petition process. Both audits are discussed in context with examples that illustrate the NRC’s implementation of its policy of transparency, in theory and practice.
美国核管理委员会(NRC)监察长办公室(OIG)于2020年11月发布的年度审计计划，包括对NRC允许“临时”访问的做法进行审计。这些是被许可方的高级管理人员和NRC管理层的非公开会议。核管理委员会的程序假定“临时”访问不涉及任何与可能影响被许可人利益的未决监管决定有关的事项。审计目的是确定NRC与行业利益相关者进行非公开互动的政策和程序是否足以防止损害机构工作人员的独立性或出现利益冲突。审计结果于2022年8月公布。2017年，OIG进行了另一项审计[USNRC, OIG-17- a -23，“审计NRC的10 CFR 2.206请愿审查程序”，2017年8月22日，ADAMS号。ML17234A561]重点关注公众对核管理委员会的信任和信心。该审计审查了NRC工作人员用于评估10份CFR§2.206执行请愿书的程序。监察长发现，在截至2016年的前三个财政年度，核管理委员会收到了38份执行请求，但其工作人员没有发布过一份执行命令。OIG的结论是，缺乏此类行动可能会对公众对该机构10cfr 2.206请愿程序有效性的看法产生不利影响。这两次审计都是在背景下讨论的，并举例说明了NRC在理论和实践中实施其透明度政策的情况。
{"title":"The Importance of Transparency in Regulation","authors":"Samuel Miranda, Ralph Caruso","doi":"10.1115/1.4056536","DOIUrl":"https://doi.org/10.1115/1.4056536","url":null,"abstract":"\u0000 The annual audit plan of the Office of the Inspector General (OIG) of the Nuclear Regulatory Commission (NRC), which was issued in November 2020, included an audit of the NRC’s practice of allowing “drop-in” visits. These are closed meetings of senior executives of licensees and NRC management. NRC procedures assume that “drop-in” visits do not concern any matters that are related to pending regulatory decisions that could affect the interests of those licensees. The audit objective was to determine whether NRC policies and procedures for non-public interactions with industry stakeholders are adequate to prevent compromise of the independence of agency staff or the appearance of conflicts of interest. The results of this audit were issued in August 2022. In 2017, the OIG conducted another audit [USNRC, OIG-17-A-23, “Audit of NRC's 10 CFR 2.206 Petition Review Process,” August 22, 2017, ADAMS No. ML17234A561] that focused on the public’s trust and confidence in the NRC. That audit examined the procedure that the NRC staff used to evaluate 10 CFR §2.206 enforcement petitions. The OIG found that the NRC staff had not issued a single enforcement order, as the result of 38 enforcement petitions that it had received in the prior three fiscal years, ending in 2016. The OIG concluded that the lack of such actions could adversely affect the public’s perspective on the effectiveness of the agency’s 10 CFR 2.206 petition process. Both audits are discussed in context with examples that illustrate the NRC’s implementation of its policy of transparency, in theory and practice.","PeriodicalId":8652,"journal":{"name":"ASME Open Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83888041","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}
Justin T. Suriano, A. Tafuni, Lewis Mullen, J. Racanelli, R. Tarantino, S. Lieber
Additive manufacturing (AM) has transformed not only how parts can be realized but also their design. Metal additive manufacturing (MAM) has increased AM’s utility toward the manufacture of functional products. This has been seen in several industries including medical device, aerospace, and the automotive industries. The main limitation of MAM continues to be the part dimensional tolerances that can be achieved, and the respective surface finish produced. Hybrid manufacturing processes have been used to address these limitations; however, there remain challenges of how to translate the component’s coordinate system from AM to subtractive post-processes. This paper explores this topic through a medical device case study. A translatable coordinate system was produced by first designing features to serve as a datum reference frame (DRF). These features were introduced by MAM and then finalized with wire-electrical discharge machining (EDM). The produced DRF features successfully prepared the component for translation from the MAM to subtractive post-process. The completed medical device component met the expected requirements with a less than 1% difference on key part nominal dimensions. In addition, the hybrid process exhibited a potential for sustainable manufacturing with a buy-to-fly ratio of 6:1. The study demonstrated that a coordinate system can be translated effectively in hybrid manufacturing by designing part features informed by both AM and wire-EDM processes.
{"title":"Medical Device Hybrid Manufacturing: Translating the Coordinate System From Metal Additive Manufacturing to Subtractive Post-Processing","authors":"Justin T. Suriano, A. Tafuni, Lewis Mullen, J. Racanelli, R. Tarantino, S. Lieber","doi":"10.1115/1.4062187","DOIUrl":"https://doi.org/10.1115/1.4062187","url":null,"abstract":"\u0000 Additive manufacturing (AM) has transformed not only how parts can be realized but also their design. Metal additive manufacturing (MAM) has increased AM’s utility toward the manufacture of functional products. This has been seen in several industries including medical device, aerospace, and the automotive industries. The main limitation of MAM continues to be the part dimensional tolerances that can be achieved, and the respective surface finish produced. Hybrid manufacturing processes have been used to address these limitations; however, there remain challenges of how to translate the component’s coordinate system from AM to subtractive post-processes. This paper explores this topic through a medical device case study. A translatable coordinate system was produced by first designing features to serve as a datum reference frame (DRF). These features were introduced by MAM and then finalized with wire-electrical discharge machining (EDM). The produced DRF features successfully prepared the component for translation from the MAM to subtractive post-process. The completed medical device component met the expected requirements with a less than 1% difference on key part nominal dimensions. In addition, the hybrid process exhibited a potential for sustainable manufacturing with a buy-to-fly ratio of 6:1. The study demonstrated that a coordinate system can be translated effectively in hybrid manufacturing by designing part features informed by both AM and wire-EDM processes.","PeriodicalId":8652,"journal":{"name":"ASME Open Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88914817","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}
The offshore installation, logistics, and commissioning activities are currently estimated to make up 20% to 30% of the capital expenditures (CAPEX) of offshore wind projects. Technical and geographical factors affect both the CAPEX during construction and the installation schedule, such as a lack of supporting port infrastructure, the availability of specialized vessels, the distance from the wind farm to shore, accessibility, water depths, and seabed conditions. In addition, there are significant risks during the construction phase, such as uncertain durations due to the sensitivity of marine operations to weather conditions. Identifying supply chain requirements is critical in the early stages of project planning in order to avoid time delays and cost overruns during the transport and installation process. This study explores and analyzes the logistic requirements and installation methods of a floating offshore wind (FOW) technology. Using an advanced forecasting and decision support tool, realistic case scenarios are simulated at a variety of potential sites for FOW deployment across the UK. Technical risks associated with installation strategies are identified and classified. The results provide a comparison of key installation performance indicators of each case scenario (e.g., installation rate per wind turbine, weather downtime). This study is of interest to researchers, offshore wind project developers, service providers, and other key stakeholders seeking to optimize planning and logistics to drive down CAPEX costs, reduce the construction downtime, and minimize risks during marine operations.
{"title":"Offshore Logistics: Scenario Planning and Installation Modeling of Floating Offshore Wind Projects","authors":"E. S. Torres, P. Thies, M. Lawless","doi":"10.1115/1.4056882","DOIUrl":"https://doi.org/10.1115/1.4056882","url":null,"abstract":"\u0000 The offshore installation, logistics, and commissioning activities are currently estimated to make up 20% to 30% of the capital expenditures (CAPEX) of offshore wind projects. Technical and geographical factors affect both the CAPEX during construction and the installation schedule, such as a lack of supporting port infrastructure, the availability of specialized vessels, the distance from the wind farm to shore, accessibility, water depths, and seabed conditions. In addition, there are significant risks during the construction phase, such as uncertain durations due to the sensitivity of marine operations to weather conditions. Identifying supply chain requirements is critical in the early stages of project planning in order to avoid time delays and cost overruns during the transport and installation process. This study explores and analyzes the logistic requirements and installation methods of a floating offshore wind (FOW) technology. Using an advanced forecasting and decision support tool, realistic case scenarios are simulated at a variety of potential sites for FOW deployment across the UK. Technical risks associated with installation strategies are identified and classified. The results provide a comparison of key installation performance indicators of each case scenario (e.g., installation rate per wind turbine, weather downtime). This study is of interest to researchers, offshore wind project developers, service providers, and other key stakeholders seeking to optimize planning and logistics to drive down CAPEX costs, reduce the construction downtime, and minimize risks during marine operations.","PeriodicalId":8652,"journal":{"name":"ASME Open Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86755928","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}
Daniel C. Ames, Gabriel L. Smith, N. Lazarus, L. Howell, S.P. Magleby
Small-scale flexible (or compliant) mechanisms are valuable in replacing rigid components while retaining comparable motion and behavior. However, fabricating such mechanisms on this scale (from 0.01 to 10 cm) proves difficult, especially with thin sheet metals. The manufacturing method of laser forming, which uses a laser to cut and bend metal into desired shapes, could facilitate this fabrication. However, specific methods for designing mechanisms formed by lasers need to be developed. This work presents laser forming as a means for creating compliant mechanisms on this scale with thin sheet metal. The unique challenges for designing mechanisms to be laser formed are explored, and new adaptations of existing designs are fabricated and discussed. The design of basic “building-block” features is developed for several mechanisms: a parallel-guided mechanism, a cross-axis flexural pivot, a lamina emergent torsional (LET) joint array, a split-tube flexure, and a bi-stable switch. These mechanisms are shown to perform repeatable behavior and motion comparable to existing nonlaser-formed versions. The further possibilities for fabricating compliant mechanisms with laser forming are explored, as advanced applications can benefit from using lasers to create compliant mechanisms from thin sheet metal.
{"title":"Laser Forming of Compliant Mechanisms","authors":"Daniel C. Ames, Gabriel L. Smith, N. Lazarus, L. Howell, S.P. Magleby","doi":"10.1115/1.4057048","DOIUrl":"https://doi.org/10.1115/1.4057048","url":null,"abstract":"\u0000 Small-scale flexible (or compliant) mechanisms are valuable in replacing rigid components while retaining comparable motion and behavior. However, fabricating such mechanisms on this scale (from 0.01 to 10 cm) proves difficult, especially with thin sheet metals. The manufacturing method of laser forming, which uses a laser to cut and bend metal into desired shapes, could facilitate this fabrication. However, specific methods for designing mechanisms formed by lasers need to be developed. This work presents laser forming as a means for creating compliant mechanisms on this scale with thin sheet metal. The unique challenges for designing mechanisms to be laser formed are explored, and new adaptations of existing designs are fabricated and discussed. The design of basic “building-block” features is developed for several mechanisms: a parallel-guided mechanism, a cross-axis flexural pivot, a lamina emergent torsional (LET) joint array, a split-tube flexure, and a bi-stable switch. These mechanisms are shown to perform repeatable behavior and motion comparable to existing nonlaser-formed versions. The further possibilities for fabricating compliant mechanisms with laser forming are explored, as advanced applications can benefit from using lasers to create compliant mechanisms from thin sheet metal.","PeriodicalId":8652,"journal":{"name":"ASME Open Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77182636","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}
Protective biology and engineering are an integrated discipline aiming to understand the naturally occurring protective mechanisms established through an evolution in response to environmental insults and genetic defects (protective biology), and develop and use engineering strategies and technologies to optimize protective processes against cell death in injury and disease based on the naturally occurring protective mechanisms (protective engineering). There exist systems protective mechanisms in mammals, including regional mechanisms activated in a disordered organ and distant mechanisms in non-disordered organs, both acting in coordination to support cell survival and prevent cell death in the disordered organ. However, these mechanisms are not all optimized for promptness and effectiveness. Protective engineering strategies can be developed and used to correct natural deficiencies and optimize protective mechanisms. This paper addresses the fundamental concepts and potential protective engineering strategies by using two examples of diseases—heart attack and ischemic stroke, leading causes of human morbidity and mortality.
{"title":"Protective Biology and Engineering","authors":"Shu Q. Liu","doi":"10.1115/1.4063086","DOIUrl":"https://doi.org/10.1115/1.4063086","url":null,"abstract":"\u0000 Protective biology and engineering are an integrated discipline aiming to understand the naturally occurring protective mechanisms established through an evolution in response to environmental insults and genetic defects (protective biology), and develop and use engineering strategies and technologies to optimize protective processes against cell death in injury and disease based on the naturally occurring protective mechanisms (protective engineering). There exist systems protective mechanisms in mammals, including regional mechanisms activated in a disordered organ and distant mechanisms in non-disordered organs, both acting in coordination to support cell survival and prevent cell death in the disordered organ. However, these mechanisms are not all optimized for promptness and effectiveness. Protective engineering strategies can be developed and used to correct natural deficiencies and optimize protective mechanisms. This paper addresses the fundamental concepts and potential protective engineering strategies by using two examples of diseases—heart attack and ischemic stroke, leading causes of human morbidity and mortality.","PeriodicalId":8652,"journal":{"name":"ASME Open Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90750315","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}
Shelby Rustom, YubRaj Paudel, S. Mujahid, Matthew S. Cagle, Prathmesh Anantwar, K. Hazeli, Robert Moser, B. Paliwal, H. Rhee, H. El Kadiri, C. Barrett
Magnesium (Mg) alloys exhibit poor room temperature ductility, which prohibits forming operations in cost-effective industrial settings and the use of these alloys in critical safety components. Profuse twinning in Mg alloys is widely associated with high strain path anisotropy and low material ductility. Twinning typically propagates across the grains through the autocatalysis phenomena in typical texture conditions. Twin–twin and twin–slip interactions often lead to high strain incompatibilities and eventually failure. One way to avoid such premature failure is to prevent the early nucleation of twins. This research tests a hypothesis that a strong yet ductile phase surrounding each individual grain in traditional polycrystals could inhibit twin accommodation effects and thus twin nucleation and autocatalysis mechanisms at grain boundaries. As a proof-of-concept for testing this hypothesis, sharply textured magnesium sheets plated with different materials were subjected to four-point bending to assess the potential of a surface/grain boundary barrier in limiting twinning extent. The results showed that Mg AZ31 alloy plated with zinc alleviated twin nucleation while improving the strength of the alloy.
{"title":"Manufacturing Strategies to Mitigate Deformation Twinning in Magnesium","authors":"Shelby Rustom, YubRaj Paudel, S. Mujahid, Matthew S. Cagle, Prathmesh Anantwar, K. Hazeli, Robert Moser, B. Paliwal, H. Rhee, H. El Kadiri, C. Barrett","doi":"10.1115/1.4056553","DOIUrl":"https://doi.org/10.1115/1.4056553","url":null,"abstract":"\u0000 Magnesium (Mg) alloys exhibit poor room temperature ductility, which prohibits forming operations in cost-effective industrial settings and the use of these alloys in critical safety components. Profuse twinning in Mg alloys is widely associated with high strain path anisotropy and low material ductility. Twinning typically propagates across the grains through the autocatalysis phenomena in typical texture conditions. Twin–twin and twin–slip interactions often lead to high strain incompatibilities and eventually failure. One way to avoid such premature failure is to prevent the early nucleation of twins. This research tests a hypothesis that a strong yet ductile phase surrounding each individual grain in traditional polycrystals could inhibit twin accommodation effects and thus twin nucleation and autocatalysis mechanisms at grain boundaries. As a proof-of-concept for testing this hypothesis, sharply textured magnesium sheets plated with different materials were subjected to four-point bending to assess the potential of a surface/grain boundary barrier in limiting twinning extent. The results showed that Mg AZ31 alloy plated with zinc alleviated twin nucleation while improving the strength of the alloy.","PeriodicalId":8652,"journal":{"name":"ASME Open Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91278161","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}
Three-bladed Darrieus-type vertical axis water turbine is a promising solution for producing electricity with minimal impact on the environment. Although considered a viable option, straight-bladed Darriues-type turbines have not been used commonly due to various operational issues; self-start and stall at low water speeds while ventilation and cavitation are limiting at high water speeds. In this study, the use of flexible blades with an aspect ratio of 2.21 is investigated at water velocities of 0.34, 0.51, 0.68, and 0.85 m/s experimentally. A stiffer turbine that has an 85–95 Shore A hardness blade starts to rotate at 0.51 m/s flow velocity. The more flexible turbine that has a 75–85 Shore A hardness blade starts to rotate at lower water velocities and experiences low rotational speeds resulting in an improved self-start. However, low rotation speed will cause a reduction in the coefficient of performance (Cp). High-speed imaging of the flow field also shows that a low tip speed ratio (TSR) helps to prevent the occurrence of ventilation and cavitation for the turbine with 75–85 Shore A hardness blades.
{"title":"The Behavior of Vertical Axis Water Turbine With Flexible Blades: Self-Start, Ventilation, and Cavitation","authors":"Emine Celik Foust","doi":"10.1115/1.4063084","DOIUrl":"https://doi.org/10.1115/1.4063084","url":null,"abstract":"\u0000 Three-bladed Darrieus-type vertical axis water turbine is a promising solution for producing electricity with minimal impact on the environment. Although considered a viable option, straight-bladed Darriues-type turbines have not been used commonly due to various operational issues; self-start and stall at low water speeds while ventilation and cavitation are limiting at high water speeds. In this study, the use of flexible blades with an aspect ratio of 2.21 is investigated at water velocities of 0.34, 0.51, 0.68, and 0.85 m/s experimentally. A stiffer turbine that has an 85–95 Shore A hardness blade starts to rotate at 0.51 m/s flow velocity. The more flexible turbine that has a 75–85 Shore A hardness blade starts to rotate at lower water velocities and experiences low rotational speeds resulting in an improved self-start. However, low rotation speed will cause a reduction in the coefficient of performance (Cp). High-speed imaging of the flow field also shows that a low tip speed ratio (TSR) helps to prevent the occurrence of ventilation and cavitation for the turbine with 75–85 Shore A hardness blades.","PeriodicalId":8652,"journal":{"name":"ASME Open Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81251882","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}
Muhammad Awaluddin Harahap, Agus Haeruman, E. Mokheimer
The increasing energy demand and rising concern about climate change have become two significant factors in finding alternative energy sources other than fossil fuels. Biomass has been implemented by several tropical countries such as Indonesia and Malaysia to answer this challenge by utilizing palm oil by-products as boiler fuels to generate steam for palm oil mill (POM) processing as well as for electricity generation. Fiber and kernel shell have become two major palm oil residues that have been implemented for this purpose. Moreover, empty fruit bunch (EFB) can also become another alternative biomass to fuel the boiler. This study is aimed at analyzing and optimizing the utilization of fiber, shell, and EFB by adjusting percentile contents of those three constituents and evaluating the CO2 production. The result of this analysis indicates that the best composition to minimize the CO2 of the biomass power plant is using 70% fiber, 0% shell, and 30% EFB. However, the increase of NO2 and SO2 must also be considered to find the correct balance between those three emissions. In addition, EFB should be pretreated (drying and shredding) before the combustion to reduce the water content and the dimension of EFB.
{"title":"Optimal Composition of Palm Oil Biomass to Minimize Biomass Power Plants’ Greenhouse Gases Emission","authors":"Muhammad Awaluddin Harahap, Agus Haeruman, E. Mokheimer","doi":"10.1115/1.4062627","DOIUrl":"https://doi.org/10.1115/1.4062627","url":null,"abstract":"\u0000 The increasing energy demand and rising concern about climate change have become two significant factors in finding alternative energy sources other than fossil fuels. Biomass has been implemented by several tropical countries such as Indonesia and Malaysia to answer this challenge by utilizing palm oil by-products as boiler fuels to generate steam for palm oil mill (POM) processing as well as for electricity generation. Fiber and kernel shell have become two major palm oil residues that have been implemented for this purpose. Moreover, empty fruit bunch (EFB) can also become another alternative biomass to fuel the boiler. This study is aimed at analyzing and optimizing the utilization of fiber, shell, and EFB by adjusting percentile contents of those three constituents and evaluating the CO2 production. The result of this analysis indicates that the best composition to minimize the CO2 of the biomass power plant is using 70% fiber, 0% shell, and 30% EFB. However, the increase of NO2 and SO2 must also be considered to find the correct balance between those three emissions. In addition, EFB should be pretreated (drying and shredding) before the combustion to reduce the water content and the dimension of EFB.","PeriodicalId":8652,"journal":{"name":"ASME Open Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76927025","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}
Tiantian Li, J. Luntz, D. Brei, P. Alexander, Wonhee Kim
The gap between the windshield and hood allows windshield wipers to operate, but causes problems gathering leaves and snow. Active morphing approaches provide an opportunity to create a windshield cowling that addresses this issue by covering the gap normally and actively curling out of the way to allow wiper operation. Most existing morphing techniques lack simultaneous large force/stroke generation, cannot perform two-way actuation, or fail to rigidly hold their position against varying loads such as wind. This article studies a novel curling air surface based on hinged T-shaped tiles that improve upon existing technologies by adding straightening actuation to out-of-plane curling with large force and deflection, while also holding position rigidly. Through vacuuming an upper curling bladder enclosing the tiles and inflating lower straightening bladders spanning the hinge lines, the air surface uncovers and covers the gap against wind loads and holds its curled position rigidly using inter-tile hard stops. An analytical surface model aggregated from multiple instances of a first principle unit curling model predicts the air surface performance. This model includes additional kinematic effects, extending the range of applicability, and additional bladder effect phenomenological terms to improve accuracy. The model is validated across scales and enables design space visualization, which is applied to design a windshield cowling. The resulting design is validated and demonstrated in a full-scale prototype. This article provides the technology concept, supporting model, and design approach to broadly apply this useful air surface to other morphing applications.
{"title":"Modeling and Design of Hinged Tile-Based Curling Air Surface for Morphing Windshield Cowling","authors":"Tiantian Li, J. Luntz, D. Brei, P. Alexander, Wonhee Kim","doi":"10.1115/1.4062220","DOIUrl":"https://doi.org/10.1115/1.4062220","url":null,"abstract":"\u0000 The gap between the windshield and hood allows windshield wipers to operate, but causes problems gathering leaves and snow. Active morphing approaches provide an opportunity to create a windshield cowling that addresses this issue by covering the gap normally and actively curling out of the way to allow wiper operation. Most existing morphing techniques lack simultaneous large force/stroke generation, cannot perform two-way actuation, or fail to rigidly hold their position against varying loads such as wind. This article studies a novel curling air surface based on hinged T-shaped tiles that improve upon existing technologies by adding straightening actuation to out-of-plane curling with large force and deflection, while also holding position rigidly. Through vacuuming an upper curling bladder enclosing the tiles and inflating lower straightening bladders spanning the hinge lines, the air surface uncovers and covers the gap against wind loads and holds its curled position rigidly using inter-tile hard stops. An analytical surface model aggregated from multiple instances of a first principle unit curling model predicts the air surface performance. This model includes additional kinematic effects, extending the range of applicability, and additional bladder effect phenomenological terms to improve accuracy. The model is validated across scales and enables design space visualization, which is applied to design a windshield cowling. The resulting design is validated and demonstrated in a full-scale prototype. This article provides the technology concept, supporting model, and design approach to broadly apply this useful air surface to other morphing applications.","PeriodicalId":8652,"journal":{"name":"ASME Open Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75838949","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}
Pendulum clocks were the prevalent time keeping standard for centuries to regulate commerce and public activities. These mechanical movements were the most accurate timekeepers globally until replaced by electric clocks. Although mainly used for decorative purposes today, the pendulum clock's working principles and mechanical behavior can serve to demonstrate fundamental science and engineering concepts. The tradeoff between a clock's quality factor, pendulum properties, and period can best be explored with multiple objective optimization and tradespace analysis methods. In this project, a Multi-Objective Genetic Algorithm (MOGA-II) and a Multi-Objective Simulated Annealing (MOSA) optimization approaches are applied to evaluate a Graham escapement street clock for pendulum mass and time accuracy with a range of the period. These clock designs vary the pendulum length, pendulum bob radius, and bob thickness. Horological concepts are used to calculate the overall performance and general utility. The numerical results show a 0.7% increase in the quality factor, and a 0.56% reduction in the mass, while maintaining the designed period by modifying the clock parameters. More importantly, these changes can provide material cost savings in a mass production scenario. Overall, the study highlights the tradeoff designer engineers have considered for decades which can now be visualized using computer tools for greater insight.
{"title":"Multi-Objective Optimization and Tradespace Analysis of a Mechanical Clock Movement Design","authors":"Yifan Xu, Cameron Turner, John Wagner","doi":"10.1115/1.4062410","DOIUrl":"https://doi.org/10.1115/1.4062410","url":null,"abstract":"\u0000 Pendulum clocks were the prevalent time keeping standard for centuries to regulate commerce and public activities. These mechanical movements were the most accurate timekeepers globally until replaced by electric clocks. Although mainly used for decorative purposes today, the pendulum clock's working principles and mechanical behavior can serve to demonstrate fundamental science and engineering concepts. The tradeoff between a clock's quality factor, pendulum properties, and period can best be explored with multiple objective optimization and tradespace analysis methods. In this project, a Multi-Objective Genetic Algorithm (MOGA-II) and a Multi-Objective Simulated Annealing (MOSA) optimization approaches are applied to evaluate a Graham escapement street clock for pendulum mass and time accuracy with a range of the period. These clock designs vary the pendulum length, pendulum bob radius, and bob thickness. Horological concepts are used to calculate the overall performance and general utility. The numerical results show a 0.7% increase in the quality factor, and a 0.56% reduction in the mass, while maintaining the designed period by modifying the clock parameters. More importantly, these changes can provide material cost savings in a mass production scenario. Overall, the study highlights the tradeoff designer engineers have considered for decades which can now be visualized using computer tools for greater insight.","PeriodicalId":8652,"journal":{"name":"ASME Open Journal of Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88286912","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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