| 1. |
- Öberg, Christina, 1970-, et al.
(author)
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- 2005
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In: IMP Conference,2005. - Rotterdam : RSM Erasmus University. ; , s. 49-
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Conference paper (peer-reviewed)
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| 2. |
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| 3. |
- Özen, Arda, et al.
(author)
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Exploring the Role of Manufacturing Parameters on Microstructure and Mechanical Properties in Fused Deposition Modeling (FDM) Using PETG
- 2021
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In: Applied Composite Materials. - : Springer Nature. - 0929-189X .- 1573-4897. ; 28:6, s. 1799-1828
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Journal article (peer-reviewed)abstract
- Additive manufacturing develops rapidly, especially, fused deposition modeling (FDM) is one of the economical methods with moderate tolerances and high design flexibility. Ample studies are being undertaken for modeling the mechanical characteristics of FDM by using the Finite Element Method (FEM). Even in use of amorphous materials, FDM creates anisotropic structures effected by the chosen manufacturing parameters. In order to investigate these process-related characteristics and tailored properties of FDM structures, we prepare FDM-printed poly(ethylene terephthalate) glycol (PETG) samples with different process parameters. Mechanical and optical characterizations are carried out. We develop 2D-digital-image-correlation code with machine learning algorithm, namely K-means cluster, to analyze microstructures (contact surfaces, the changes in fiber shapes) and calculate porosity. By incorporating these characteristics, we draw CAD images. A digital twin of mechanical laboratory tests are realized by the FEM. We use computational homogenization approach for obtaining the effective properties of the FDM-related anisotropic structure. These simulations are validated by experimental characterizations. In this regard, a systematic methodology is presented for acquiring the anisotropy from the process related inner substructure (microscale) to the material response at the homogenized length scale (macroscale). We found out that the layer thickness and overlap ratio parameters significantly alter the microstructures and thereby, stiffness of the macroscale properties.
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| 4. |
- ÖZEN, MUSTAFA, 1984, et al.
(author)
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Symmetrical doherty amplifier with high efficiency over large output power dynamic range
- 2014
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In: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781479938698
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Conference paper (peer-reviewed)abstract
- For the conventional Doherty power amplifiers, asymmetrical cells are used to achieve high efficiency over large (> 6 dB) output power dynamic ranges, i.e. larger class-C cell. In this paper, it will be theoretically proven that high efficiency over large dynamic ranges also can be achieved using symmetrical devices, while still maintaining full voltage and current swing of both transistor cells. Using a smaller class-C cell compared to the asymmetrical Doherty has the advantages of higher gain and power added efficiency (PAE). The proposed symmetrical Doherty concept is experimentally verified by a 3.5 GHz 28 Watt circuit demonstrator fabricated using identical GaN HEMT devices. An average power added efficiency of 52% and adjacent power leakage ratio of -52 dB is obtained with 9 dB peak-to-average power-ratio 20 MHz LTE test signals.
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| 5. |
- Aad, G., et al.
(author)
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- 2012
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In: Journal of High Energy Physics. - 1029-8479 .- 1126-6708. ; :11
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Journal article (peer-reviewed)
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| 6. |
- Özdemir, Metin, 1977-, et al.
(author)
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Improving dissemination of evidence‐based programs through researcher–practitioner collaboration
- 2014
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In: New Directions for Youth Development. - : Wiley. - 1533-8916 .- 1537-5781. ; 141, s. 107-116
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Journal article (peer-reviewed)abstract
- Prevention field has achieved major advances in developing, implementing, and testing the efficacy of preventive interventions in controlled settings. Nevertheless, there is still a gap in translating the success of programs in efficacy trials into real-life settings. Dissemination of evidence-based programs is a major challenge. The authors argue that promoting adoption of evidence-based programs requires further improvements in three areas, and collaboration between researchers and practitioners. First, there is a need to develop a holistic assessment system encompassing both risk/need and readiness assessments. Second, there is need for new methods for improving implementation quality. Third, prevention research needs to focus more on identifying the mechanisms that explain how programs work and the core elements of the program. Both researchers and practitioners have roles and opportunities to collaborate to achieve developments in these areas.
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| 7. |
- Gustavsson Tingvall, Patrik, et al.
(author)
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- 2006
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In: Economics of Innovation and New Technology. - : Routledge. - 1043-8599 .- 1476-8364. ; 15:2, s. 101-118
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Journal article (peer-reviewed)abstract
- We test whether predictions of the Aghion et al. (Aghion, P., Bloom, N., Blundell, R., Griffith, R. and Howitt, P. (2004) Competition and Innovation: An Inverted U Relationship. NBER Working Paper series, No. 9269.) model are supported by firm-level data. In particular, we analyze if there is an inverted U-shaped relation between competition and R&D. Results show that the inverted U-shaped relation is supported by the Herfindahl index but not by the price cost margin. Using the Herfindahl index, results suggest that breaking up monopolies increases R&D, whereas further increases in competition most likely lead to reduced R&D. Comparing different estimators, we find that time series-based estimators typically result in less clear-cut results, probably driven by a lack of time series variation in measures of competition.
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| 8. |
- Aad, G., et al.
(author)
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- 2012
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swepub:Mat__t (peer-reviewed)
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| 9. |
- Aad, G., et al.
(author)
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- 2012
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Journal article (peer-reviewed)
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| 10. |
- Aad, G., et al.
(author)
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Readiness of the ATLAS Tile Calorimeter for LHC collisions
- 2010
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In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 70:4, s. 1193-1236
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Journal article (peer-reviewed)abstract
- The Tile hadronic calorimeter of the ATLAS detector has undergone extensive testing in the experimental hall since its installation in late 2005. The readout, control and calibration systems have been fully operational since 2007 and the detector has successfully collected data from the LHC single beams in 2008 and first collisions in 2009. This paper gives an overview of the Tile Calorimeter performance as measured using random triggers, calibration data, data from cosmic ray muons and single beam data. The detector operation status, noise characteristics and performance of the calibration systems are presented, as well as the validation of the timing and energy calibration carried out with minimum ionising cosmic ray muons data. The calibration systems' precision is well below the design value of 1%. The determination of the global energy scale was performed with an uncertainty of 4%.
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