| 1. |
- Angenendt, Knut, 1982, et al.
(författare)
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Ionic liquid structures from large DFT calculations using mindless configurations
- 2010
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Ingår i: Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 114:48, s. 20577-20582
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Tidskriftsartikel (refereegranskat)abstract
- Three different popular imidazolium based ionic liquids (ILs); EMI-BF4, EMI-PF6, and EMI-TFSI, have been modeled by DFT calculations (B3LYP/6-311+G*) using large, up to 130 atom cluster models, for a better understanding of the structure and ion ion interactions in these ILs and ILs in general. Particular emphasis has been put on the role of appropriate starting structures and how the present large models differ from the ion-pair models of ILs generally used. The system size normalized ion ion interaction energies are shown to converge rapidly, and conformational equilibria and higher order properties like IR spectra are shown to be valuable as quality criteria. The explicit inclusion of an IL environment by the large cluster approach is also compared to using an implicit, continuum, strategy via SCRF C-PCM calculations.
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| 2. |
- Carlsson, Anna K, 1966, et al.
(författare)
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Rollator related pedestrian single accidents and collision events in Sweden
- 2022
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Ingår i: Traffic Safety Research (TSR). - : Lund University. - 2004-3082. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- Rollators (four-wheel walkers in USA; zimmer frames in UK) are commonly used as mobility aids for the elderly and people with a variety of disabilities. Pedestrian rollator users are a sub-group of Vulnerable Road Users (VRUs), although this group is rarely recognised in traffic safety contexts. The aim of this study is to extract and analyse rollator related pedestrian accident and injury data in Sweden. The results will provide valuable insight into the risks and obstacles rollator users are exposed to in the traffic environment and may in the long term contribute to improving the mobility of this group. The current study is based on data from 2,020 accidents involving 2,305 persons extracted from the Swedish Traffic Accident Data Acquisition (STRADA) database. For consistency reasons, a subset of data (N = 745) was analysed in order to investigate the development of accidents over a period of 10 years. Thereafter, each accident in the whole data set was registered as either single or collision. The results show that the number of rollator accidents in Sweden increased by approximately 80% during 2007–2016. Females dominate the injury statistics of single accidents, collisions, as well as fatal outcome, which may be due to exposure and/or differences in physical characteristics. Single accidents are much more common than collisions (n=1,668 and n=352, respectively) and the injury consequences are at least as serious. Data from the present study have revealed that the frequency of minor injuries (ISS 1–3) is 4.3 times, moderate (ISS 4–8) 6.0 times and serious injuries (ISS 9–15) 8.9 times higher in single accidents than in collisions. Fatal injuries are, however, more common in collision events (33 in comparison to 8). The vast majority of single accidents (99%) was due to falls. Many of the single accidents (29%) were caused by ground level differences (typically a curb) or due to surface conditions (19%). Collisions involved cars, trucks or buses in 91% of cases, occurring predominantly in car parks (31%) and on (zebra) crossings (30%). In 54% of cases the vehicles reversed into the rollator. Abbreviated Injury Scale (AIS) 3+ injuries were dominated by head (36%) and torso (33%) injuries in collision events, and hip fractures (71%) in single accidents. The present study shows that further research into rollator user related accidents, both single accidents and collision events, is required. In order to introduce appropriate measures, future work should follow up on accident and injury developments and further improve the quality of mobility aid related accident data in general. Improved stability and design, proper training programmes, effective maintenance services, development of a supporting infrastructure would contribute to increased safety for rollator users.
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| 3. |
- Chen, Zhe, et al.
(författare)
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Nano-scale characterization of white layer in broached Inconel 718
- 2017
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Ingår i: Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing. - Amsterdam : Elsevier BV. - 0921-5093 .- 1873-4936. ; 684, s. 373-384
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Tidskriftsartikel (refereegranskat)abstract
- The formation mechanism of white layers during broaching and their mechanical properties are not well investigated and understood to date. In the present study, multiple advanced characterization techniques with nano-scale resolution, including transmission electron microscopy (TEM), transmission Kikuchi diffraction (TKD), atom probe tomography (APT) as well as nano-indentation, have been used to systematically examine the microstructural evolution and corresponding mechanical properties of a surface white layer formed when broaching the nickel-based superalloy Inconel 718.TEM observations showed that the broached white layer consists of nano-sized grains, mostly in the range of 20–50 nm. The crystallographic texture detected by TKD further revealed that the refined microstructure is primarily caused by strong shear deformation. Co-located Al-rich and Nb-rich fine clusters have been identified by APT, which are most likely to be γ′ and γ′′ clusters in a form of co-precipitates, where the clusters showed elongated and aligned appearance associated with the severe shearing history. The microstructural characteristics and crystallography of the broached white layer suggest that it was essentially formed by adiabatic shear localization in which the dominant metallurgical process is rotational dynamic recrystallization based on mechanically-driven subgrain rotations. The grain refinement within the white layer led to an increase of the surface nano-hardness by 14% and a reduction in elastic modulus by nearly 10% compared to that of the bulk material. This is primarily due to the greatly increased volume fraction of grain boundaries, when the grain size was reduced down to the nanoscale.
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| 4. |
- Dufek, Jan, 1978
(författare)
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Building the nodal nuclear data dependences in a many-dimensional state-variable space
- 2011
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Ingår i: Annals of Nuclear Energy. - : Elsevier BV. - 0306-4549 .- 1873-2100. ; 38:7, s. 1569-1577
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Tidskriftsartikel (refereegranskat)abstract
- We present new methods for building the polynomial-regression based nodal nuclear data models. Thedata models can reflect dependences on a large number of state variables, and they can consider varioushistory effects. Suitable multivariate polynomials that approximate the nodal data dependences are identifiedefficiently in an iterative manner. The history effects are analysed using a new sampling scheme forlattice calculations where the traditional base burnup and branch calculations are replaced by a largenumber of diverse burnup histories. The total number of lattice calculations is controlled so that the datamodels are built to a required accuracy.
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| 7. |
- Engström, Tomas, 1950, et al.
(författare)
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Alternativ montering
- 2008
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Ingår i: Chukyo Keiei Kenkyu (academic japanese journal). ; 18:1, s. 73 - 153
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Tidskriftsartikel (refereegranskat)abstract
- A translation into Japanese of the three authors’’ book written for and financed by the Swedish Metal Workers Union (IF Metall is Swedish). Namely, “Alternativ montering. Principer och erfarenheter från fordonsindustrin”, Engström, Jonnsson and Medbo 2005). Which was financed by this organization (i.e. Metall), and which summarizes the authors’’ insights and experiences in more popular terms (used for this organization’s education, as well as made available on their website) (see other publications registered in Chalmers Public library CPL).
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| 8. |
- Engström, Tomas, 1950, et al.
(författare)
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Alternatives to Line Assembly: Some Swedish examples
- 1996
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Ingår i: International Journal of Industrial Ergonomics. - 1872-8219 .- 0169-8141. ; 17:3, s. 235-245
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, some criticism of Lean production has occurred, focusing among other things on the working conditions and the susceptibility of traditional assembly work in a society upgrading the demands for a more humanized work. Recently, this criticism has also concerned the technical aspects of this type of manufacturing. Because of this, alternatives to line assembly merit some attention. Experiences from some innovative production systems operated in the Swedish automotive industry during the last two decades are of particular interest. These unconventional production systems feature autonomous work groups and extended work cycles. These types of production systems are elucidated in detail by means of e.g nuance the concept of utilising buffers, i.e. there are different types of buffers (or buffer functions) as is classified (or clarified) in this publications.
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| 9. |
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| 10. |
- Engström, Tomas, 1950, et al.
(författare)
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Engström, T. and Jonsson, D. (2016). Development and Application of (Certain) Principles for Work Structuring
- 2015
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- This manuscript is an extensive book (or preprint not yet finished to due to one the author’s retirement) summaries four decades research and development work dealing with development work of alternatives to assembly lines and assembly line work, as have been the case for one of the two authors from a technical point of departure (he is a senior research competency in mechanical engineering). On the other hand, the other authors have an even longer time perspective, but he has a social science background (he is a senior research competency within sociology for more than four decades). That is, they have been working at Chalmers University of Technology respectively at Gothenburg University all throughout their professional life. This while they both are belonging to a normative sociotechnical research tradition earlier at hand in the Gothenburg area, which actually has emanated from specific precursors at Gothenburg University (i.e. mainly professor Edmund Dalhström at the Department of Sociology), this research tradition was later on brought over to Chalmers by professor Ulf Karlsson responsible for operation management at the same university. It is fair to state that this research area required the amalgamation of technical as well as social science aspects. Efforts that during the passing years have been substantiated by extensive help and support from the Swedish automotive industry (Saab Scania and Volvo companies, as well as other parts of the industry) and also from several governmental research foundations. In fact, a truer cross and multi-science research approach than what usually is at hand has always been required. The extensive book manuscript is exceeding more than 600 pages. Twelve chapters exists as well as also a number of freestanding appendixes and the necessary (all-pervading) definitions of primary concepts and term in combination with explaining various synonyms and homonyms (a particular dilemma for cross and multi-science approaches) (i.e. are we in agreement with the text it alone, or are we eventually together understanding the underlying meaning). Moreover, the text is scrutinized by word process programs in form of Word as well as by the professional English check-up program Grammarly) and all of the necessary figures are completed. i.e. several revisions of this manuscript have been iterated first between the authors and later on against other parties. Most notable are external revisions by two senior research competencies (professor David Bennet responsible for operation management at Aston Business School, Birmingham and professor Lennart Nilsson responsible for vocational learning and training at Gothenburg University, Gothenburg). The authoring just described (involving the initiated hinted just above) have occupied our minds for more than one decade (our co-authoring and work with specific Japanese research colleagues, have most certainly underlined a need for careful writing, since among other things just nicking the practitioners’ nomenclature will be misleading, as is also the case while relaying on one or a few scientific research areas) (see some of the other publications registrated in Chalmers Public Library CLP) (it is most certainly an extensive research area, and the skills needed to be mastered in order to understand are indeed wide). The underlying principles of any (real-life) assembly system must, according to our understanding, are inventible required to be explained. Thus, it is important for the analyst to grasp whether or not the principle applied is correct or if the practice is questionable. This means, metaphorically speaking, is the original drawings accurate or have the execution (practice) faulty. The two most sociotechnically advanced (real-life) assembly systems both proved to be successful (more efficient and flexible in relation to comparable assembly lines, and work and work conditions were far better). They were both based on correct principles (i.e. the nowadays defunct Volvo Uddevalla plant and the so-called assembly docks at the Volvo Tuve heavy truck chassis plant located in Gothenburg). As will become evident by the content brought forward in this extensive book manuscript. A comment. The most socio-technically advanced assembly system designs inventible requires reformed/reconfigured information systems dealing with product data (which in turn defines the product architecture and product variation). In fact, no any such (real-life) plant or assembly system would work as anticipated otherwise. And this publication is to some extent describing some selected aspects of this (very) dilemma (changing information systems are usually not something considered than designing assembly systems) (thus are totally new plants – and in turn totally new information systems – most often the real practical change to create something unorthodox) (however, which scientist will gain such opportunities, this is really rare, i.e. the projection of the Volvo Uddevalla plant was thus an exception and the trust given by the industry – by Volvo Uddevalla project organisation – was appreciated by some of the authors).
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