International University College Leuven

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Dewulf W.,Wichita State University | Overcash M.,Wichita State University | Hauschild M.Z.,Technical University of Denmark | Duflou J.R.,International University College Leuven
International Journal of Life Cycle Assessment | Year: 2012

Purpose This report presents two case studies, one for both the screening approach and the in-depth approach, demonstrating the application of the life cycle assessment-oriented methodology for systematic inventory analysis of the machine tool use phase of manufacturing unit processes, which has been developed in the framework of the CO2PE! collaborative research programme (CO2PE! 2011) and is described in part 1 of this paper (Kellens et al. 2011). Screening approach The screening approach, which provides a first insight into the unit process and results in a set of approximate LCI data, relies on representative industrial data and engineering calculations for energy use and material loss. This approach is illustrated by means of a case study of a drilling process. In-depth approach The in-depth approach, which leads to more accurate LCI data as well as the identification of potential for environmental improvements of the manufac- turing unit processes, is subdivided into four modules, including a time study, a power consumption study, a consumables study and an emissions study, in which all relevant process in- and outputs are measured and analysed in detail. The procedure of this approach, together with the proposed CO2PE! template, is illustrated by means of a case study of a laser cutting process. Results The CO2PE! methodology aims to provide highquality LCI data for the machine tool use phase of manufacturing unit processes, to be used in life cycle inventory databases and libraries, as well as to identify potential for environmental improvement based on the indepth analysis of individual manufacturing unit processes. Two case studies illustrate the applicability of the methodology. © 2011 Springer-Verlag.


Dewulf W.,International University College Leuven | Overcash M.,Wichita State University | Hauschild M.Z.,Technical University of Denmark
International Journal of Life Cycle Assessment | Year: 2012

Purpose: This report proposes a life-cycle analysis (LCA)-oriented methodology for systematic inventory analysis of the use phase of manufacturing unit processes providing unit process datasets to be used in life-cycle inventory (LCI) databases and libraries. The methodology has been developed in the framework of the CO2PE! collaborative research programme (CO2PE! 2011a) and comprises two approaches with different levels of detail, respectively referred to as the screening approach and the in-depth approach. Methods: The screening approach relies on representative, publicly available data and engineering calculations for energy use, material loss, and identification of variables for improvement, while the in-depth approach is subdivided into four modules, including a time study, a power consumption study, a consumables study and an emissions study, in which all relevant process in- and outputs are measured and analysed in detail. The screening approach provides the first insight in the unit process and results in a set of approximate LCI data, which also serve to guide the more detailed and complete in-depth approach leading to more accurate LCI data as well as the identification of potential for energy and resource efficiency improvements of the manufacturing unit process. To ensure optimal reproducibility and applicability, documentation guidelines for data and metadata are included in both approaches. Guidance on definition of functional unit and reference flow as well as on determination of system boundaries specifies the generic goal and scope definition requirements according to ISO 14040 (2006) and ISO 14044 (2006). Results: The proposed methodology aims at ensuring solid foundations for the provision of high-quality LCI data for the use phase of manufacturing unit processes. Envisaged usage encompasses the provision of high-quality data for LCA studies of products using these unit process datasets for the manufacturing processes, as well as the in-depth analysis of individual manufacturing unit processes. Conclusions: In addition, the accruing availability of data for a range of similar machines (same process, different suppliers and machine capacities) will allow the establishment of parametric emission and resource use estimation models for a more streamlined LCA of products including reliable manufacturing process data. Both approaches have already provided useful results in some initial case studies (Kellens et al. 2009; Duflou et al. (Int J Sustain Manufacturing 2:80-98, 2010); Santos et al. (J Clean Prod 19:356-364, 2011); UPLCI 2011; Kellens et al. 2011a) and the use will be illustrated by two case studies in Part 2 of this paper (Kellens et al. 2011b). © 2011 Springer-Verlag.


Molenaers A.,Catholic University of Leuven | Molenaers A.,International University College Leuven | Baets H.,BASF | Pintelon L.,Catholic University of Leuven | And 2 more authors.
International Journal of Production Economics | Year: 2012

This paper proposes a spare part classification method based on item criticality. Starting from a multi-criteria analysis, the proposed model converts relevant criteria impacting item criticality into a single score presenting the criticality level. The obtained criticality level is used to rationalize the efficiency of the spare parts inventory policy. The model presents the multi-criteria classification problem in a logic decision diagram where AHP is used to solve the multi-criteria decision sub-problems at the different decision nodes of the diagram. The method was tested and implemented in a petrochemical plant and the results of this case study are presented. © 2012 Elsevier B.V. All rights reserved.


Goethals P.,International University College Leuven | Chaobal H.,Anesthetech Inc. | Reynaerts D.,Catholic University of Leuven | Schaner D.,Anesthetech Inc.
Journal of Clinical Monitoring and Computing | Year: 2014

We present a new device for verifying endotracheal tube (ETT) position that uses specialized sensors intended to distinguish anatomical features of the trachea and esophagus. This device has the potential to increase the safety of resuscitation, surgery, and mechanical ventilation and decrease the morbidity, mortality, and health care costs associated with esophageal intubation and unintended extubation by potentially improving the process and maintenance of endotracheal intubation. The device consists of a tactile sensor connected to the airway occlusion cuff of an ETT. It is intended to detect the presence or absence of tracheal rings immediately upon inflation of the airway occlusion cuff. The initial study detailed here verifies that a prototype device can detect contours similar to tracheal rings in a tracheal model. © 2013 Springer Science+Business Media.


Dewulf W.,International University College Leuven | Dewulf W.,Catholic University of Leuven | Tan Y.,International University College Leuven | Tan Y.,Catholic University of Leuven | And 2 more authors.
CIRP Annals - Manufacturing Technology | Year: 2012

The polychromatic spectrum of X-ray beams causes beam hardening artifacts in reconstructed computed tomography (CT) models. This leads to unwanted grey value variations in CT models, thus hampering accurate material analysis and inspection. Therefore, beam hardening correction algorithms have been developed and improved since the early 1970s, which enhance the CT image quality by compensating for beam hardening effects. However, beam hardening correction often results in less contrast around the edge. In addition, experiments show an increased influence of surrounding material on the object dimensions after segmentation, hence increasing the measurement uncertainty. This paper presents the results of systematic investigations into the effect of beam hardening correction on the measurement accuracy and uncertainty for CT metrology applications. © 2012 CIRP.


Duflou J.R.,Catholic University of Leuven | Kellens K.,Catholic University of Leuven | Renaldi,Catholic University of Leuven | Guo Y.,Catholic University of Leuven | And 2 more authors.
CIRP Annals - Manufacturing Technology | Year: 2012

High variation can be observed in energy requirement values reported for unit processes as applied in discrete manufacturing. Different methods for determining such values have been suggested, ranging from theoretic energy determination till statistically determined time averaged values based on experimental process measurements. In this paper the theoretic process energy method is compared to results as obtained from two methods suggested for systematic determination of Life Cycle Inventory (LCI) database entries for unit processes. Examples from different process categories are presented to illustrate the discrepancies observed between the approaches and to illustrate the error range linked to the method selection. © 2012 CIRP.


De Schutter B.,International University College Leuven
Games and Culture | Year: 2011

This study aimed to explore the use of digital games among older adults and provide a set of "benchmark data" with respect to the uses and gratifications of these players. To find out who these older players of digital games are, what games they prefer, and what playing motives they have, an exploratory survey was administered among 124 individuals aged between 45 and 85 years old. The results of this survey confirm that the majority of the older digital game audience exists of solitary players with a particular fondness for casual PC games. The most popular playing motive among the respondents was challenge, while social interaction proved to be the most important predictor for the time that respondents invested in playing digital games. © The Author(s) 2011.


Kellens K.,Catholic University of Leuven | Dewulf W.,International University College Leuven | Duflou J.R.,Catholic University of Leuven
AIP Conference Proceedings | Year: 2011

This paper presents the results of a data collection effort allowing to assess the overall environmental impact of the air bending process using the CO2PE!-Methodology. First the different modes of the air bending process are investigated including both productive and non-productive modes. In particular consumption of electric power is recorded for the different modes. Subsequently time studies allow determining the importance of productive and nonproductive modes of the involved process. The study demonstrates that the influence of standby losses can be substantial. In addition to life cycle analysis in depth process analysis also provides insight in achievable environmental impact reducing measures towards machine tool builders and eco-design recommendations for product developers. The energy consumption of three different machine tool architectures are analysed and compared within this paper. © 2011 American Institute of Physics.


Duflou J.R.,Catholic University of Leuven | Kellens K.,Catholic University of Leuven | Dewulf W.,International University College Leuven
CIRP Journal of Manufacturing Science and Technology | Year: 2011

Manufacturing processes, as used for discrete part manufacturing, are responsible for a substantial part of the environmental impact of products, but are still poorly documented in terms of their environmental footprint. The lack of thorough analysis of manufacturing processes has as consequence that optimization opportunities are often not recognized and that improved machine tool design in terms of ecological footprint has only been targeted for a few common processes. To address these shortcomings, a worldwide consortium of universities and research institutes launched the CO2PE! - Initiative (Cooperative Effort on Process Emissions in Manufacturing) [1]. This paper starts with an overview of the current shortcomings in terms of the coverage of production steps during LCA studies with existing tools. Further on, the CO2PE! - methodology used to analyze manufacturing unit processes is summarized and some initial case studies conducted at the K.U. Leuven, which allowed to identify significant improvement potential, are presented. © 2011 CIRP.


Dingenen B.,Catholic University of Leuven | Staes F.F.,Catholic University of Leuven | Janssens L.,Catholic University of Leuven | Janssens L.,International University College Leuven
Journal of Biomechanics | Year: 2013

Time to stabilization (TTS) has been introduced as a method to analyze dynamic postural stability during jump and landing tasks, but has also been applied during the transition task from double-leg stance (DLS) to single-leg stance (SLS). However, the application of the originally described TTS technique during the latter task has some important limitations. The first goal of this study was to present an adapted version of the TTS technique to provide an effective alternative method to better analyze postural stability during the transition from DLS to SLS. The second goal was to study the influence of pathology and different speeds on postural stability outcomes. Fifteen healthy control subjects and 15 subjects with chronic ankle instability (CAI) performed the transition task on their preferred speed and as fast as possible, with eyes open and with eyes closed. Subjects with CAI performed the transition significantly slower when moving at their preferred speed with eyes closed. The time subjects needed to reach a new stability point was not discriminative between groups and largely dependent on movement speed. However, the amount of sway after this new stability point was significantly increased in the CAI group and when eyes were closed. The results of this study suggest that subjects with CAI have a decreased ability to overcome the postural perturbation created by the voluntary movement from DLS to SLS. Focusing only on TTS during the transition from DLS to SLS may lead at least in some cases to misinterpretations when assessing postural stability. © 2013.

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