| 1. |
- Ahmadkhaniha, Donya, et al.
(författare)
-
Effect of SiC particle size and heat-treatment on microhardness and corrosion resistance of NiP electrodeposited coatings
- 2018
-
Ingår i: Journal of Alloys and Compounds. - : Elsevier BV. - 0925-8388 .- 1873-4669. ; 769, s. 1080-1087
-
Tidskriftsartikel (refereegranskat)abstract
- Electrodeposition of NiP composite coatings with nano and sub-micron sized SiC has been carried out to investigate the possibility of replacing hard chromium coatings. The composition and structure of the coatings were evaluated by energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) analysis, respectively. Microhardness was measured by Vickers indentation and polarization measurements were carried out to study the corrosion behavior of the coatings. The results showed that submicron particles can be codeposited with a higher content as compared to nano sized ones. However, even if a smaller amount of the nano-sized SiC particles are incorporated in the coating, the contribution to an increasing microhardness was comparable with the submicron sized particles, which can be related to the higher density of codeposited particles. SiC particles did not change the anodic polarization behavior of NiP coatings in a 3.5% NaCl solution. Finally, the effect of heat-treatment on the coatings properties at 400 °C for 1 h was studied to investigate the contribution of particles and heat-treatment on hardness and corrosion properties. It was found that the heat-treatment doubled the microhardness and changed the anodic polarization behavior of the coatings from passive to active with respect to the as-plated conditions.
|
|
| 2. |
- Ahmadkhaniha, Donya, et al.
(författare)
-
Electrodeposition of Ni high P composite coatings containing nano and submicro ceramic particles
- 2017
-
Ingår i: EUROCORR 2017 - The Annual Congress of the European Federation of Corrosion, 20th International Corrosion Congress and Process Safety Congress 2017. - : Czech Association of Corrosion Engineers.
-
Konferensbidrag (refereegranskat)abstract
- In this study, electrodeposition of Ni-P composite coatings has been carried out to investigate the possibility of replacing hard chromium coatings. Therefore, electrodeposition of Ni-P based composite coating with different SiC particle size (50 nm, 100 nm and 500 nm) or B4C (500 nm) was performed. The coating's composition was evaluated by energy dispersive spectroscopy (EDS), microhardness of the coatings was measured by Vickers indentor and polarization measurements were carried out to study the corrosion behavior of the coatings. The results showed that B4C particles can codeposit in higher percent respect to SiC ones. Ceramic particles increased microhardness of Ni-P coatings to 700HV0.01. The polarization behavior of all the coatings in 3.5% NaCl was similar in as plated state proving that particles did not hindered the passive behaviour. Finally, the effect of heat-treatment (at 400 ºC for 1 hour) on the coating's properties was studied to compare the contribution of particles and heat-treatment on mechanical and corrosion properties of the coatings. Heat-treatment increased the coating's microhardness and changed the anodic polarization behavior of the coatings respect to the as plated conditions. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. All rights reserved.
|
|
| 3. |
- Alirezaie, Marjan, 1980-, et al.
(författare)
-
SmartEnv as a network of ontology patterns
- 2018
-
Ingår i: Semantic Web. - : IOS Press. - 1570-0844 .- 2210-4968. ; 9:6, s. 903-918
-
Tidskriftsartikel (refereegranskat)abstract
- In this article we outline the details of an ontology, called SmartEnv, proposed as a representational model to assist the development process of smart (i.e., sensorized) environments. The SmartEnv ontology is described in terms of its modules representing different aspects including physical and conceptual aspects of a smart environment. We propose the use of the Ontology Design Pattern (ODP) paradigm in order to modularize our proposed solution, while at the same time avoiding strong dependencies between the modules in order to manage the representational complexity of the ontology. The ODP paradigm and related methodologies enable incremental construction of ontologies by first creating and then linking small modules. Most modules (patterns) of the SmartEnv ontology are inspired by, and aligned with, the Semantic Sensor Network (SSN) ontology, however with extra interlinks to provide further precision and cover more representational aspects.The result is a network of 8 ontology patterns together forming a generic representation for a smart environment. The patterns have been submitted to the ODP portal and are available on-line at stable URIs.
|
|
| 4. |
- Alirezaie, Marjan, et al.
(författare)
-
SmartEnv ontology in E-care@home (Short paper)
- 2018
-
Ingår i: CEUR Workshop Proceedings. - : CEUR-WS. ; , s. 72-79, s. 72-79
-
Konferensbidrag (refereegranskat)abstract
- In this position paper we briey introduce SmartEnv ontology which relies on SEmantic Sensor Network (SSN) ontology and is used to represent different aspects of smart and sensorized environments. We will also talk about E-carehome project aiming at providing an IoT-based health-care system for elderly people at their homes. Furthermore, we refer to the role of SmartEnv in Ecarehome and how it needs to be further extended to achieve semantic interoperability as one of the challenges in development of autonomous health care systems at home.
|
|
| 5. |
- Alklind Taylor, Anna-Sofia, 1975-, et al.
(författare)
-
Guardian Angel : Using Lighting Drones to Improve Traffic Safety, Sense of Security, and Comfort for Cyclists
- 2023
-
Ingår i: Lecture Notes in Computer Science. - Cham : Springer. - 9783031480461 - 9783031480478 ; , s. 209-223
-
Konferensbidrag (refereegranskat)abstract
- Active mobility, such as biking, faces a common challenge in Swedish municipalities due to the lack of adequate lighting during the dark winter months. Insufficient lighting infrastructure hinders individuals from choosing bicycles, despite the presence of well-maintained bike paths and a willingness to cycle. To address this issue, a project has been undertaken in the Swedish municipality of Skara for an alternative lighting solution using drones. A series of tests have been conducted based on drone prototypes developed for the selected bike paths. Participants were invited to cycle in darkness illuminated by drone lighting and share their mobility preferences and perception. This paper summarizes the users’ perception of drone lighting as an alternative to fixed lighting on bike paths, with a special focus on the impact on travel habits and the perceived sense of security and comfort. Most participants were regular cyclists who cited bad weather, time, and darkness as significant factors that deterred them from using bicycles more frequently, reducing their sense of security. With drone lighting, the participants appreciated the illumination’s moonlight-like quality and its ability to enhance their sense of security by illuminating the surroundings. On the technology side, they gave feedback on reducing the drone’s sound and addressing lighting stability issues. In summary, the test results showcase the potential of drone lighting as a viable alternative to traditional fixed lighting infrastructure, offering improved traffic safety, sense of security, and comfort. The results show the feasibility and effectiveness of this innovative approach, supporting transformation towards active and sustainable mobility, particularly in regions facing lighting challenges.
|
|
| 6. |
- Andersson, Magnus, et al.
(författare)
-
Architectural knowledge in inter-organizational IT innovation
- 2008
-
Ingår i: Journal of strategic information systems. - : Elsevier BV. - 0963-8687 .- 1873-1198. ; 17:1, s. 19-38
-
Tidskriftsartikel (refereegranskat)abstract
- This paper examines the front-end process of inter-organizational IT innovation. In particular, it focuses on the nature and role of architectural knowledge. Such knowledge is important for development of architectures capable of serving the goals of heterogeneous actors and technologies. Yet, surprisingly little research has been done on how architectural knowledge may be developed through collective achievements. This paper presents a theoretical model of architectural knowledge development in inter-organizational IT innovation. Applying this model throughout an action research project within the Swedish transport industry, the paper identifies four dimensions of architectural knowledge that proved important for facilitating an industry-wide ubiquitous computing environment. The four dimensions are technology capability awareness, use context sensitivity, business model understanding, and boundary-spanning competence. We conclude the paper by outlining the theoretical and strategy implications of the model and the four dimensions of architectural knowledge. © 2008 Elsevier B.V. All rights reserved.
|
|
| 7. |
- Belov, Ilja, et al.
(författare)
-
Application of CFD Modelling for Energy Efficient Humidity Mangement of an Electronics Enclosure in Storage under Severe Climatic Conditions
- 2008
-
Ingår i: International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Micro-Systems, 2008. - : IEEE. - 9781424421275 ; , s. 430-437
-
Konferensbidrag (refereegranskat)abstract
- A CFD modelling methodology including experimental validation has been developed and applied for investigation of anti-moisture measures in a non- hermetic electronics enclosure containing a number of printed circuit boards, and placed in a severe storage environment. In the climatic test the temperature and the relative humidity have been varried from +33degC to +71degC and from 14% to 80%, respectively. Enclosure heater solutions have been parametrically studied by simulation. A heating strategy involving various power levels has been determined, which is just sufficient to maintain the internal relative humidity below 60%, thereby reducing the risk for dew formation on the electronics assembly.
|
|
| 8. |
- Belov, Ilja, et al.
(författare)
-
Effect of fillets on heat transfer in a rheocast aluminium heatsink
- 2016
-
Ingår i: 2016 17th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE). - : IEEE. - 9781509021062
-
Konferensbidrag (refereegranskat)abstract
- The effect of fillets formed between the base and plate fins of rheocast aluminium heatsinks on the thermal resistance of the heatsinks has been quantified by simulation. Simulation methodology, including sequential optimization has been developed in order to determine hotspot distributions where the fillets have the maximum effect. Combination of different fillet dimensions with various base thickness levels and aluminium alloys having inhomogeneous thermal conductivity have been investigated. For the studied cases, the effect of fillets on heatsink thermal resistance differs from negligible to 6%. The results would guide thermal designers on contribution of fillets to the heat transfer in multi-fin heatsinks for natural convection.
|
|
| 9. |
- Belov, Ilja, et al.
(författare)
-
Experimental and CFD evaluation of active anti-condensation methods for non-hermetic cabinets
- 2018
-
Ingår i: 2018 19th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems (EuroSimE). - : Institute of Electrical and Electronics Engineers (IEEE). - 9781538623596 ; , s. 1-6
-
Konferensbidrag (refereegranskat)abstract
- Experimental evaluation of several active anti-condensation methods for application in non-hermetic electronics enclosures was performed in harsh climatic conditions, including RH = 70% and T = 43 °C. The studied methods included blowing the air along the exposed surface, combination of blowing and air heating as well as local heating of the exposed surface in natural convection conditions. The purpose was to prevent/remove the dew on/from the exposed surface of a micro-condensation sensor. The difference between the methods was quantified in terms of time for dew removal. The power consumption aspects were discussed. A CFD based optimization methodology was developed to determine the heating profiles for the local anti-condensation PCB heater in a non-hermetic cabinet exposed to the quickly changing climatic conditions. The potential for 60% energy savings was revealed by simulation.
|
|
| 10. |
- Belov, Ilja, et al.
(författare)
-
Finite element modeling of silver electrodeposition for evaluation of thickness distribution on complex geometries
- 2016
-
Ingår i: Materials & design. - : Elsevier. - 0264-1275 .- 1873-4197. ; 90, s. 693-703
-
Tidskriftsartikel (refereegranskat)abstract
- The paper reveals benefits of multi-disciplinary computer simulation and parametric studies in the design of silver plating process for improved coating distribution. A finite element model of direct current silver plating is experimentally validated for an Assaf panel without agitation. The model combines tertiary current distribution with Butler-Volmer electrode kinetics and computational fluid dynamics at a very low flow-rate. The effect of charge transfer coefficients on the throwing power of the process is quantified for the studied geometry, and variation of cathodic current density and exchange current density is investigated. A simpler model based on secondary current distribution is employed to quantify the effect of electrolyte conductivity on the throwing power of the process. A model combining tertiary current distribution and computational fluid dynamics has been developed and experimentally validated for simulation of complex telecom component electroplating in agitated electrolyte. The effect of current density on the process throwing power is quantified. Recommendations regarding modeling methodology and the effect of electrochemical and process parameters on the thickness distribution have been developed.
|
|
