| 1211. |
- Laukkanen, P., et al.
(författare)
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Formation and destabilization of Ga interstitials in GaAsN : Experiment and theory
- 2012
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Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 86:19, s. 195205-
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Tidskriftsartikel (refereegranskat)abstract
- Using first-principles total energy calculations we have found complex defects induced by N incorporation in GaAsN. The formation energy of the Ga interstitial atom is very significantly decreased due to local effects within the defect complex. The stability of the Ga interstitials is further increased at surfaces. The present results suggest that the energetically favorable Ga interstitial atoms are much more abundant in GaAsN than the previously considered N defects, which have relatively large formation energies. Our synchrotron radiation core-level photoemission measurements support the computational results. The formation of harmful Ga interstitials should be reduced by incorporating large group IV B atoms in GaAsN.
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| 1212. |
- Laukkanen, P., et al.
(författare)
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Ultrathin (1x2)-Sn layer on GaAs(100) and InAs(100) substrates : A catalyst for removal of amorphous surface oxides
- 2011
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 98:23, s. 231908-1-231908-3
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Tidskriftsartikel (refereegranskat)abstract
- Amorphous surface oxides of III-V semiconductors are harmful in many contexts of device development. Using low-energy electron diffraction and photoelectron spectroscopy, we demonstrate that surface oxides formed at Sn-capped GaAs(100) and InAs(100) surfaces in air are effectively removed by heating. This Sn-mediated oxide desorption procedure results in the initial well-defined Sn-stabilized (1x2) surface even for samples exposed to air for a prolonged time. Based on ab initio calculations we propose that the phenomenon is due to indirect and direct effects of Sn. The Sn-induced surface composition weakens oxygen adsorption.
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| 1213. |
- Laurenti, Rafael, 1980-, et al.
(författare)
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Characterizing the Sharing Economy State of the Research : a Systematic Map
- 2019
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Ingår i: Sustainability. - : MDPI. - 2071-1050. ; 11:20
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Forskningsöversikt (refereegranskat)abstract
- The sharing economy is an emerging niche for innovation capable of disrupting established socio-technical and economic regimes. Because of this potential to cause radical changes in a wide array of domains, research in multiple disciplines addressing various aspects entailing this phenomenon is proliferating. In this emerging body of literature, the understanding and framing of the sharing economy are often different. Without knowledge about the current state of the research related to the sharing economy, delineating research trends, gaps, and needs for directing effectively primary research are not possible. This study aimed to synthesize the state and distribution of existing publications related to the sharing economy in multiple disciplines. We used the systematic mapping technique to scope, identify, and classify the publications at a fine level of granularity. We reviewed 589 journal articles (published from 1978 to 2017), and 454 met the selection criteria. The journal articles reviewed were published in 284 different journals. Intriguingly, 15 journals published five to 13 publications each and 221 journals had a single article about the topic. Journals belonging to the subject areas “business, management and accounting” (42.1%) and “social sciences” (35.2%) published more than 70% of the reviewed publications. Accommodation (19.8%) and car and ridesharing (17.2%) were the two most prominent sectors; 50.2% of the publications addressed C2C transactions (10.6% B2C, 24.4% more than one type); 62.3% were about accessing resources, and 5.1% concerned transfer of ownership (i.e., second-hand or donation); and 19.2% covered access and transfer of ownership simultaneously. While empirical studies were the majority (53.1%, when comparing with conceptual ones), qualitative approaches were most common (51.5% against 24.9% quantitative and 17.4% mixed methods). Literature review (22.9%), survey (13.2%), case study (7.3%) and interview (7%) were the most frequently used methods. User behavior (26.4%), business models and organizational aspects (22.7%), institution and governance system (18.7%), conceptualization matters (17%), and sustainability evaluation (15.3%) are research clusters identified from a grounded approach. The link between user behavior and net environmental impacts of sharing options was the largest gap found in the research needing attention from a sustainability perspective. Accordingly, multidisciplinary investigations quantifying behavioral root causes, magnitude, and likelihood of environmental rebound effects using real-world data are strongly encouraged.
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| 1214. |
- Laurenti, Rafael, 1980-, et al.
(författare)
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The Socio-Economic Embeddedness of the Circular Economy : An Integrative Framework
- 2018
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Ingår i: Sustainability. - : MDPI. - 2071-1050. ; 10:7
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Tidskriftsartikel (refereegranskat)abstract
- Global economies have been characterised by a large dependency of material inflows from natural stocks, an exponential growth of material stock-in-use in the built environment, and the extensive disposal of waste material outflows to anthropogenic sinks. In this context, the concept of the circular economy has emerged, promising to circulate the stock-in-use of materials and transforming output waste material flows back into useful resources while promoting job and value creation. These promises have drawn the attention and interest of policymakers and industry, and gained popularity across society. Despite its apparent emergent legitimacy and diffusion, a few essential adjustments still need to be addressed so that circular economy initiatives can actually deliver on their promises without leading to negative unintended effects. First, a complete entanglement with the existing formal economy is fundamentally needed; this implies valuing the preservation of natural stocks and pricing material input flows adequately. Secondly, a recognition of its socio-economic embeddedness is essentially necessary. The decision-making of societal actors affects material configuration, which in turn affects societal actors; this important feedback loop needs to be explicitly taken into account in circular economy initiatives. The aim of this short communication paper is to explore these pervasive challenges in a broad context of sustainable physical resource management. An integrative framework for recognising the socio-economic embeddedness of the circular economy in practice and the role of the formal economic system in realising its ambitions is proposed.
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| 1215. |
- Lauss, Martin, et al.
(författare)
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Robust assignment of cancer subtypes from expression data using a uni-variate gene expression average as classifier
- 2010
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Ingår i: BMC Cancer. - : Springer Science and Business Media LLC. - 1471-2407 .- 1471-2407. ; 10, s. 532-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Genome wide gene expression data is a rich source for the identification of gene signatures suitable for clinical purposes and a number of statistical algorithms have been described for both identification and evaluation of such signatures. Some employed algorithms are fairly complex and hence sensitive to over-fitting whereas others are more simple and straight forward. Here we present a new type of simple algorithm based on ROC analysis and the use of metagenes that we believe will be a good complement to existing algorithms.Results: The basis for the proposed approach is the use of metagenes, instead of collections of individual genes, and a feature selection using AUC values obtained by ROC analysis. Each gene in a data set is assigned an AUC value relative to the tumor class under investigation and the genes are ranked according to these values. Metagenes are then formed by calculating the mean expression level for an increasing number of ranked genes, and the metagene expression value that optimally discriminates tumor classes in the training set is used for classification of new samples. The performance of the metagene is then evaluated using LOOCV and balanced accuracies.Conclusions: We show that the simple uni-variate gene expression average algorithm performs as well as several alternative algorithms such as discriminant analysis and the more complex approaches such as SVM and neural networks. The R package rocc is freely available at http://cran.r-project.org/web/packages/rocc/index.html.
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| 1216. |
- Leander, John, et al.
(författare)
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A decision support framework for fatigue assessment of steel bridges
- 2018
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Ingår i: Engineering Failure Analysis. - : Elsevier BV. - 1350-6307 .- 1873-1961. ; 91, s. 306-314
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Tidskriftsartikel (refereegranskat)abstract
- Many bridges are approaching or have already passed their expected service life. For steel bridges, fatigue is often the decisive degradation phenomenon that theoretically puts restrictions on a continued use. At the same time, fatigue is also afflicted with large uncertainties on the resistance side as well as on the action effect side. An accurate assessment of the service life will require measures outside the governing regulations but understanding what steps to take and how to consider the outcome for decisions on interventions can be a difficult task for a non-expert. This paper presents possible assessment actions and a decision support framework for rational decisions on interventions to extend the theoretical service life of existing bridges. A case study of a critical railway bridge is incorporated to demonstrate the framework. The aim is to provide a tool for bridge managers on how to evaluate and procure different assessment actions.
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| 1217. |
- Leander, John, et al.
(författare)
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Risk-based planning of assessment actions for fatigue life prediction
- 2017
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Ingår i: 2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, Funchal, Madeira, Portugal. - : Elsevier. ; 5, s. 1221-1228
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Konferensbidrag (refereegranskat)abstract
- It is vital to extend the service life of existing bridges as far as possible as a means for improved sustainability leading to reduced economic cost and resource consumption. This requirement is especially valid for bridges which are critical components of highly vulnerable infrastructure systems. Achieving this aim requires enhanced methods involving various actions and methods influencing different aspects of the assessment process. A framework is presented in this paper based on three common factors used to describe the assessment actions of existing bridges; (i) model sophistication, (ii) uncertainty consideration, and (iii) knowledge content. The framework elucidates the influence of different decisions on the assessment process and facilitates the planning of appropriate assessment actions. Furthermore, it provides a basic scheme for a risk-based decision analysis for determining suitable assessment actions or activities. A fatigue assessment of an existing bridge detail is used to demonstrate the application of the framework in practical cases.
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| 1218. |
- Lee, S. -K, et al.
(författare)
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Reduction of the barrier height and enhancement of tunneling current of titanium contacts using embedded Au nano-particles on 4H and 6H silicon carbide
- 2002
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Ingår i: Materials Science Forum. - : Trans Tech Publications Inc.. - 0255-5476 .- 1662-9752. ; 389-393:2, s. 937-940
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated the electrical characteristics of Ti Schottky contacts with embedded Au nano-particles on various types of epilayers of SiC (4H- and 6H-SiC). From our current-voltage (I-V) and capacitance-voltage (C-V) measurements, we observed that Ti Schottky contacts with embedded Au nano-particles had 0.19 eV (n-4H-SiC) and 0.15 eV (n-6H-SiC) lower barrier height than those of particle free Ti Schottky contacts. In order to understand this reduction of the Schottky barrier height (SBH) for Ti Schottky contacts with embedded Au nano-particles, it has been proposed that SBH lowering is caused by an enhanced electric field due to the small size of the Au nano-particles and the large SBH difference. We have also tested these contacts on highly doped n-and p-type SiC material to study ohmic contacts using linear TLM measurements.
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| 1219. |
- Lee, S. K., et al.
(författare)
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Reduction of the Schottky barrier height on silicon carbide using Au nano-particles
- 2002
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Ingår i: Solid-State Electronics. - 0038-1101 .- 1879-2405. ; 46:9, s. 1433-1440
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Tidskriftsartikel (refereegranskat)abstract
- By the incorporation of size-selected Au nano-particles in Ti Schottky contacts on silicon carbide, we could observe considerably lower the barrier height of the contacts. This result could be obtained for both n- and p-type Schottky contacts using current-voltage and capacitance voltage measurements. For n-type Schottky contacts, we observed reductions of 0.19-0.25 eV on 4H-SiC and 0.15-0.17 eV on 6H-SiC as compared with particle-free Ti Schottky contacts. For p-type SiC, the reduction was a little lower with 0.02-0.05 eV on 4H- and 0.10-0.13 eV on 6H-SiC. The reduction of the Schottky barrier height is explained using a model with enhanced electric field at the interface due to the small size of the circular patch and the large difference of the barrier height between Ti and Au.
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| 1220. |
- Legrain, Pierre, et al.
(författare)
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The Human Proteome Project : Current State and Future Direction
- 2011
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Ingår i: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 10:7
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Tidskriftsartikel (refereegranskat)abstract
- After the successful completion of the Human Genome Project, the Human Proteome Organization has recently officially launched a global Human Proteome Project (HPP), which is designed to map the entire human protein set. Given the lack of protein-level evidence for about 30% of the estimated 20,300 protein-coding genes, a systematic global effort will be necessary to achieve this goal with respect to protein abundance, distribution, subcellular localization, interaction with other biomolecules, and functions at specific time points. As a general experimental strategy, HPP research groups will use the three working pillars for HPP: mass spectrometry, antibody capture, and bioinformatics tools and knowledge bases. The HPP participants will take advantage of the output and cross-analyses from the ongoing Human Proteome Organization initiatives and a chromosome-centric protein mapping strategy, termed C-HPP, with which many national teams are currently engaged. In addition, numerous biologically driven and disease-oriented projects will be stimulated and facilitated by the HPP. Timely planning with proper governance of HPP will deliver a protein parts list, reagents, and tools for protein studies and analyses, and a stronger basis for personalized medicine. The Human Proteome Organization urges each national research funding agency and the scientific community at large to identify their preferred pathways to participate in aspects of this highly promising project in a HPP consortium of funders and investigators.
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