| 1. |
- Lindberg, Siv M, et al.
(författare)
-
A product semantic study of the influence of the sense of touch on the evaluation of wood-based materials
- 2013
-
Ingår i: Materials & design. - : Elsevier BV. - 0264-1275 .- 1873-4197 .- 0261-3069. ; 52, s. 300-307
-
Tidskriftsartikel (refereegranskat)abstract
- Based on product semantics, this study investigated how the tactile attributes of wood and wood-based composites are perceived and interpreted semantically. The wood-based samples included ash, birch, elm, oak, pine, OSB (oriented strand board), two wood pulp-reinforced polylactide composites, Comp A and B and one wood-fiber reinforced polypropene composite, Comp C. The subjects rated the samples by the descriptive words natural, exclusive, eco-. friendly, rough, inexpensive, reliable, warm, modern, snug and solid. The most significant differences between the samples were found for roughness and for the descriptors, reliable, natural and solid. A principal component analysis yielded three attributes based on the tactile perceptions: reliable, old-. fashioned and smooth. The solid wood pieces were perceived as natural and oak was perceived as being exclusive. The composite materials presented a greater variation in terms of perceived attributes than the wood specimens.
|
|
| 2. |
- Åkerfeldt, Maria, 1982, et al.
(författare)
-
Textile piezoelectric sensors – melt spun bi-component poly(vinylidene fluoride) fibres with conductive cores and poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) coating as the outer electrode
- 2014
-
Ingår i: Fashion and Textiles. - : Springer Science and Business Media LLC. - 2198-0802. ; 1:1
-
Tidskriftsartikel (refereegranskat)abstract
- The work presented here addresses the outer electroding of a fully textile piezoelectric strain sensor, consisting of bi-component fibre yarns of β-crystalline poly(vinylidene fluoride) (PVDF) sheath and conductive high density polyethylene (HDPE)/carbon black (CB) core as insertions in a woven textile, with conductive poly(3,4-ethylene dioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS) coatings developed for textile applications. Two coatings, one with a polyurethane binder and one without, were compared for the application and evaluated as electrode material in piezoelectric testing, as well as tested for surface resistivity, tear strength, abrasion resistance and shear flexing. Both coatings served their function as the outer electrodes in the system and no difference in this regard was detected between them. Omission of the binder resulted in a surface resistivity one order of magnitude less, of 12.3 Ω/square, but the surface resistivity of these samples increased more upon abrasion than the samples coated with binder. The tear strength of the textile coated with binder decreased with one third compared to the uncoated substrate, whereas the tear strength of the coated textile without binder increased with the same amount. Surface resistivity measurements and scanning electron microscopy (SEM) images of the samples subjected to shear flexing showed that the coatings without the binder did not withstand this treatment, and that the samples with the binder managed this to a greater extent. In summary, both of the PEDOT:PSS coatings could be used as outer electrodes of the piezoelectric fibres, but inclusion of binder was found necessary for the durability of the coating.
|
|
| 3. |
- André, Alann, et al.
(författare)
-
Finite element delamination study of a notched composite plate under flexural loads
- 2009
-
Ingår i: ICCM-17, 17th International Conference on Composite Materials, Edinburgh, UK. - London : IOM Communications.
-
Konferensbidrag (refereegranskat)abstract
- The delamination process in notched composite plates under flexural loading has been investigated using finite element analysis. Cohesive elements implemented in the commercial finite element package ABAQUS have been used in the region around the drilled-hole, and positioned between layers where delamination was observed during experiments presented in an accompanying paper. The delamination initiation and subsequent propagation was studied between the layers at the tension side separately and simultaneously. For all FE models, the load displacement curve was in good agreement with the one from experiments. However, the amount of damage reported from the fractography study was more extensive than that predicted by the models. Finally, it was shown that the models with only one cohesive layer show significantly different results to that of the model with four cohesive layers in terms of size of the degradation area.
|
|
| 4. |
- Cho, Sung-Woo, et al.
(författare)
-
Injection-molded nanocomposites and materials based on wheat gluten
- 2011
-
Ingår i: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 48:1, s. 146-152
-
Tidskriftsartikel (refereegranskat)abstract
- This is, to our knowledge, the first study of the injection molding of materials where wheat gluten (WG) is the main component. In addition to a plasticizer (glycerol), 5 wt.% natural montmorillonite clay was added. X-ray indicated intercalated clay and transmission electron microscopy indicated locally good clay platelet dispersion. Prior to feeding into the injection molder, the material was first compression molded into plates and pelletized. The filling of the circular mold via the central gate was characterized by a divergent flow yielding, in general, a stronger and stiffer material in the circumferential direction. It was observed that 20–30 wt.% glycerol yielded the best combination of processability and mechanical properties. The clay yielded improved processability, plate homogeneity and tensile stiffness. IR spectroscopy and protein solubility indicated that the injection molding process yielded a highly aggregated structure. The overall conclusion was that injection molding is a very promising method for producing WG objects.
|
|
| 5. |
|
|
| 6. |
- Yao, Yiming, 1957, et al.
(författare)
-
Microstructure of plasma sprayed Al2O3-3wt%TiO2 coating using freeze granulated powder
- 2016
-
Ingår i: Journal of Materials Science and Chemical Engineering. - : Scientific Research Publishing, Inc.. - 2327-6045 .- 2327-6053. ; 4:7, s. 8-14
-
Tidskriftsartikel (refereegranskat)abstract
- This study is aiming at controlling the microstructure of plasma sprayed Al2O3-TiO2 composite coatings using freeze granulated powders. As sprayed and sintered Al2O3+3wt%TiO2 powders were air plasma spayed with industry process parameters and compared with a commercial powder. The resulting coatings were investigated with respect to powder flowability, porosity and microstructure of the granules. The results showed that microstructure and melting fraction in the coatings could be tailored with the freeze granulation process and heat treatment conditions.
|
|
| 7. |
- Andersson, Anton, et al.
(författare)
-
Ground granulated iron silicate slag as supplementary cementitious material: Effect of prolonged grinding and granulation temperature
- 2023
-
Ingår i: Cleaner Materials. - : Elsevier. - 2772-3976. ; 10
-
Tidskriftsartikel (refereegranskat)abstract
- The metallurgical and cement industries contribute significantly to anthropogenic carbon dioxide emissions. Utilizing oxidic by-products from the metallurgical industry as supplementary cementitious materials (SCMs) can improve resource efficiency and reduce emissions from cement production. Iron silicate copper slags have been studied as SCMs, but mainly in systems where Portland cement is used as an activator. There is limited research on the inherent reactivity of the slag under changing processing conditions. The present study offers insight into the effect of granulation temperature and grinding on the inherent reactivity of an industrially produced iron silicate copper slag. The results showed that granulation temperature had an insignificant effect on reactivity, while grinding generated substantial improvements. The latter effect was concluded to stem from the increased specific surface area, increased number of sites for nucleation and growth of hydrates, and changes in the inherent reactivity owing to structural changes induced by the grinding.
|
|
| 8. |
- Chasoglou, Dimitris, 1982, et al.
(författare)
-
Effect of reducing agents on the sintering of chromium alloyed PM steels
- 2013
-
Ingår i: Proceedings EURO PM2013 Congress & Exhibition, 15-18 September 2013, Gothenburg, Sweden. - : European Powder Metallurgy Association (EPMA). ; 2, s. 297-302
-
Konferensbidrag (refereegranskat)abstract
- The control of the surface chemistry during sintering is the key factor for the successful and efficientproduction of PM parts, especially for powders containing elements with high affinity to oxygen such as chromium.The effect of different reducing agents was investigated by performing sintering trials on water atomized steel powder pre-alloyed with 3 wt.% Cr with and without the addition of graphite as well as using atmospheres with varying hydrogen content. The use of thermal analysis and photoacoustic spectroscopy in combination with results from fractographic investigation showed that oxide reduction is enhanced with the presence of hydrogen even if the main reduction mechanism is the carbothermal reactions. Oxides rich in Cr, Mn and Si were formed during sintering for all appliedconditions. The findings are summarized in a simple model describing the enclosure of oxides during the sinter-neckdevelopment and the changes in surface chemistry during the process.
|
|
| 9. |
- Chasoglou, Dimitris, 1982, et al.
(författare)
-
Optimisation of sintering atmospheres for controlled sintering of PM steels
- 2013
-
Ingår i: Proceedings EURO PM2013 Congress & Exhibition, 15-18 September 2013, Gothenburg, Sweden. - : European Powder Metallurgy Association (EPMA). ; 2, s. 339-346
-
Konferensbidrag (refereegranskat)abstract
- The use of elements with high oxygen affinity such as Cr or Mn in PM steels has been met with skepticism although such grades are attractive options for structural applications. They require strict control of the used atmosphere during the sintering process. Various techniques such asphotoacoustic spectroscopy (PAS) and continuous CO/CO2/H2O measurements have been implemented for atmosphere monitoring during sintering trials of Cr-alloyed steel powder. The used atmospheres were nitrogen-hydrogen blends (0,3,10 and 100% H2) as well as vacuum. The progress of the oxidation/reduction processes was also followed with thermogravimetric studies. The pressed and sintered samples were examined using optical and electron microscopy in combination with EDX in order to evaluate the formed reaction products. The presence of hydrogen, even in smallamounts, is positive for the oxide reduction. Results show that careful adjustment of the used atmosphere leads to efficient production of steel components based on Cr -prealloyed powders.
|
|
| 10. |
|
|
