| 1. |
- Azizoğlu, Yağız, 1986-, et al.
(author)
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Finite Element Analysis of cold pilgering using elastic roll dies
- 2017
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In: Procedia Engineering. - : Elsevier. - 1877-7058. ; 207, s. 2370-2375
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Journal article (peer-reviewed)abstract
- A finite element model of cold pilgering with elastic roll dies have been developed and used to investigate the influence of roll die deformation on the material flow, contact region, roll separating force and tube dimensions. Full scale experiments were performed to validate the contact surface and tube dimensions. The results show that the influence of roll die flattening is not significant on the contact length. However, elastic deformation of roll die has strong influence on both the wall thickness reduction and roll separating force. Thus it is recommended to consider elasticity of roll dies when forces and tube dimensions are estimated.
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| 2. |
- Abadikhah, Hossein, 1987, et al.
(author)
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A systematic approach to derive dynamic equations for homogeneous and functionally graded micropolar plates
- 2017
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In: Procedia Engineering. - : Elsevier BV. - 1877-7058 .- 1877-7058. ; 199, s. 1429-1434
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Conference paper (peer-reviewed)abstract
- This work considers a systematic derivation process to obtain hierarchies of dynamical equations for micropolar plates being either homogeneous or with a functionally graded (FG) material variation over the thickness. Based on the three dimensional micropolar continuum theory, a power series expansion technique of the displacement and micro-rotation fields in the thickness coordinate of the plate is adopted. The construction of the sets of plate equations is systematized by the introduction of recursion relations which relates higher order powers of displacement and micro-rotation terms with the lower order terms. This results in variationally consistent partial differential plate equations of motion and pertinent boundary conditions. Such plate equations can be constructed in a systematic fashion to any desired truncation order, where each equation order is hyperbolic and asymptotically correct. The resulting lowest order flexural plate equation is seen to be of a generalized Mindlin type. The numerical results illustrate that the present approach may render accurate solutions of benchmark type for both homogeneous and functionally graded micropolar plates provided higher order truncations are used. Moreover, low order truncations render new sets of plate equations that can act as engineering plate equations, e.g. of a generalized Mindlin type.
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| 3. |
- Ainegren, Mats, 1963-, et al.
(author)
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A portable roller ski rolling resistance measurement system
- 2013
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In: The Impact of Technology on Sport V. - : Elsevier. ; , s. 79-83
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Conference paper (peer-reviewed)abstract
- Roller skis are used by cross-country skiers, biathletes and ski-orienteers for their snow-free training and in roller ski competitions. Additionally, much of the current sports research into the physiology and biomechanics of crosscountry skiing is conducted indoors on treadmills using roller skis. For elite athletes, the differences in performance are quite small, thus emphasising the importance of knowing the roller skis' rolling resistance coefficient, especially in connection to research and roller ski competitions. The purpose of this study was to develop a roller ski rolling resistance measurement system (P-RRMS) that is portable and therefore useful in different contexts and locations. The P-RRMS was designed as a small treadmill, equipped with roller ski stabilizing lateral supports and a screwed bar for applying different vertical loads on the roller ski. The design uses only one force sensor, with possible measurements of three directions of force and torque around three axes. The weight of the P-RRMS is 100 kg and it is equipped with wheels to facilitate transportation.
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| 4. |
- Alavian Ghavanini, Farzan, 1978, et al.
(author)
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Growth characterization of vertically aligned carbon nanofibers on top of TiN buffer layer for nanoelectromechanical devices
- 2010
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In: Procedia Engineering, 24th Eurosensor 24th Conference Linz, AUSTRIA, SEP 05-08, 2010. - : Elsevier BV. - 1877-7058. ; 5, s. 1115-1118
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Conference paper (peer-reviewed)abstract
- Initial growth of vertically aligned carbon nanofibers (VACNFs) from Ni catalyst seeds in the range of 40 to 100 nm as fabricated using hole-mask colloidal lithography on top of reactively sputtered TiN is studied. We observe that the initial growth conditions could cause a growth mode transition from base-type to tip-type. We attribute this transition to a change in the crystallographic orientation of the Ni catalyst seeds induced by initial growth conditions. A convenient method to deposit stoichiometric TiN films is also presented.
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| 5. |
- Amin, Muhammad, 1979, et al.
(author)
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Carbon nanotubes as base material for fabrication of gap waveguide components
- 2014
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In: Procedia Engineering. - : Elsevier BV. - 1877-7058 .- 1877-7058. ; 87, s. 931-934
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Conference paper (peer-reviewed)abstract
- Carbon nanotubes are being used here as a base material for rapid prototyping of a high frequency device. It has beenimplemented on a ridge gap resonator for 220-325 GHz which has previously been fabricated in Si. Microfabrication with Si has its benefits but it is time consuming when etching high ratio structures. CNT based structures offer a rapid and low cost turnover for prototyping. Measurements comparing the CNT-based structure to a previously made Si structure and simulations are presented. The unloaded Q-values and the loss/mm are presented from simulations, Si-based resonator measurements and CNT-based resonator measurements.
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| 6. |
- Andersen, Lars Vabbersgaard, et al.
(author)
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Variation in models for simple dynamic structure–soil–structure interaction problems
- 2017
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In: Procedia Engineering. - : Elsevier BV. - 1877-7058. ; 199, s. 2306-2311
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Conference paper (peer-reviewed)abstract
- To account for dynamic cross-coupling of structures via the soil, a computational model must be accurate enough to provide the correct overall behaviour of the scattered wave field. However, simplicity is also important when a model should be used for design purposes, especially in the early design stages and feasibility studies. The paper addresses the accuracy of simple models in which an array of structures is simplified into blocks placed on the ground surface or embedded within the soil. Comparisons are made between models that account or do not account, in a proper manner, for the inertia and embedment of the structures. Especially, the limitations of simplified models are discussed regarding their capability to quantify the insertion loss accurately.
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| 7. |
- Andersson, Mike, et al.
(author)
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SiC-FET sensors for selective and quantitative detection of VOCs down to ppb level
- 2016
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In: Procedia Engineering. - : Elsevier. - 1877-7058. ; 168, s. 216-220
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Journal article (peer-reviewed)abstract
- With the increased interest in development of cheap, simple means for indoor air quality monitoring, and specifically in relation to certain well-known pollutant substances with adverse health effects even at very low concentrations, such as different Volatile Organic Compounds (VOCs), this contribution aims at providing an overview of the development status of the silicon carbide field effect transistor (SiC FET) based sensor platform for ppb level detection of VOCs. Optimizing the transducer design, the gas-sensitive material(s) composition, structure and processing, its mode of operation - applying temperature cycled operation in conjunction with multivariate data evaluation - and long-term performance it has been possible to demonstrate promising resultsregarding the sensor technology’s ability to achieve both single-digit ppb sensitivity towards e.g. naphthalene as well as selective detection of individual substances in a mixture of different VOCs.
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| 8. |
- Andersson, Niclas, et al.
(author)
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The Interface between industrialized and project based construction
- 2017
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In: Procedia Engineering. - : Elsevier. - 1877-7058. ; 196, s. 220-227
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Journal article (peer-reviewed)abstract
- Today, digitalization is the single most significant change factor for the construction sector as well as for society in general, which will bring new opportunities for intelligent and sustainable cities, efficient management of available resources and a general reduction of carbon emissions. Digitalization will enable continuous and integrated information exchange between all actors of the construction process. The development of an integrated digital information infrastructure for the construction sector will reach beyond the traditional project process and e.g. include the urban planning processes, where geographical information systems (GIS) are currently used, and the manufacturing processes of industrialized construction where e.g. product data management (PDM) systems constitute the product information platform. This study provides a survey of the interface between industrialized and project based construction from an information and business relation perspective. The purpose and main objectives of the study are to review and map the current information exchange between industrialized and project based construction in order to identify existing and potential areas of digitalization and standardization for improved information flow. The survey finds that industrial suppliers still frequently use company specific product standards, that PDF-, Word- or Excel-files constitute the normally used file format and that recurrent restructuring and re-entering of information from one system to another characterize the information exchange. Further, contractors approach industrialized construction in three distinctive ways, and express a generally growing interest for industrialized construction, which include closer and more long-term business relations with industrial suppliers. Despite the identified problems of information exchange and lack of common standards, the survey concludes that improved business relations provides the most urgent area of development in order to better integrate the industrialized and project based construction.
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| 9. |
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| 10. |
- Aziz, Maryam, et al.
(author)
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Mobility impact on the end-to-end delay performance for VoIP over LTE
- 2012
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In: Procedia Engineering. - Coimbatore : Elsevier. - 1877-7058. ; , s. 491-498
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Conference paper (peer-reviewed)abstract
- Long Term Evolution (LTE) is the last step towards the 4th generation of cellular networks. This revolution is necessitated by the unceasing increase in demand for high speed connection on LTE networks. This paper focuses on the performance evaluation of End-to-End delay under variable mobility speed for VoIP (Voice over IP) in the LTE network. In the course of E2E performance evaluation, realizing simulation approach three scenarios have been modeled using OPNET 16.0. The first one is the baseline network while among other two, one consists of VoIP traffic solely and the other consists of FTP along with VoIP. E2E delay has been measured for both scenarios in various cases under the varying mobility speed of the node. Simulation results have been studied and presented in terms of comparative performance analysis of the three network scenarios. In light of the result analysis, the performance quality of a VoIP network (with and without the presence of additional network traffic) in LTE has been determined and discussed. The simulation results for baseline VoIP network (non-congested) congested VoIP network and congested VoIP with FTP network show that as the speed of node is gradually increased, E2E delay slightly increases.
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