The Experts below are selected from a list of 17940 Experts worldwide ranked by ideXlab platform
Igor Krupa - One of the best experts on this subject based on the ideXlab platform.
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mechanical sorption and adhesive properties of composites based on low density polyethylene filled with date palm wood powder
Materials & Design, 2014Co-Authors: Mariam Al Ali Almaadeed, Zuzana Nogellova, Matej Micusik, I Novak, Igor KrupaAbstract:Abstract Low density polyethylene (LDPE) was blended with date palm wood powder (DPW) to prepare composites with concentrations of filler ranging from 10 to 70 wt.%. The Younǵs modulus of the composites significantly increased with an increase in the filler content in the entire concentration range. The maximum value of 1933 MPa for the composite filled with 70 wt.% of the filler is approximately 13 times higher than that for the neat LDPE. The presence of the filler improved the flexural strength, which was represented by the flexural stress at peak. The flexural strength of 17.8 MPa for the composite filled with 70 wt.% of the filler was two-times greater than that for the neat LDPE. The water absorption test revealed that the composites had a strong tendency to absorb water, which was dependent on the filler content. The experimental data were compared with several theoretical models.
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the mechanical and adhesive properties of electrically and thermally conductive polymeric composites based on high density polyethylene filled with nickel powder
Materials & Design, 2013Co-Authors: Volkan Cecen, Igor Krupa, Abderrahim Boudenne, Jan Prokes, I NovakAbstract:Abstract Electrically and thermally conductive composites made using high density polyethylene (HDPE) matrix blended with a special grade of branch-structured nickel particles were studied. Composites with high filler content were highly electrically and thermally conductive. The electrical conductivity of composites reached a value of 8.3 × 103 S m−1 when filled with 30 vol.% of the filler, and the thermal conductivity obtained using this filler content was found to be 1.99 W m−1 K−1. The percolation concentration of the filler within the HDPE matrix, which was determined from electrical conductivity measurements, was determined to be 8 vol.%. Young’s modulus of composites significantly increased from 606 MPa to 1057 MPa when composites were filled with 20 vol.% of the filler. Further increasing the filler content caused no further increase in Young’s modulus, probably due to high aggregation of the filler. The stress at break of the composites behaved nonlinearly; the low filler content suppressed necking, resulting in a decrease in stress at break, whereas higher filler content (higher than 10 vol.%) led to reinforcement of the composites and therefore increased the stress at break. The presence of nickel particles throughout the HDPE matrix increased the hydrophilicity of the composites. The contact angle of water on the neat HDPE decreased from 93° to 80° as the nickel content of the matrix was increased to 13 vol.% of nickel. Further increases in the filler content did not alter the contact angle. Similarly, the strength of the adhesive joint formed by the composite and aluminum foil increased from a value of 16 N m−1 for the neat HDPE to 27 N m−1 when the HDPE matrix was filled with 13 vol.% of the filler.
I Novak - One of the best experts on this subject based on the ideXlab platform.
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mechanical sorption and adhesive properties of composites based on low density polyethylene filled with date palm wood powder
Materials & Design, 2014Co-Authors: Mariam Al Ali Almaadeed, Zuzana Nogellova, Matej Micusik, I Novak, Igor KrupaAbstract:Abstract Low density polyethylene (LDPE) was blended with date palm wood powder (DPW) to prepare composites with concentrations of filler ranging from 10 to 70 wt.%. The Younǵs modulus of the composites significantly increased with an increase in the filler content in the entire concentration range. The maximum value of 1933 MPa for the composite filled with 70 wt.% of the filler is approximately 13 times higher than that for the neat LDPE. The presence of the filler improved the flexural strength, which was represented by the flexural stress at peak. The flexural strength of 17.8 MPa for the composite filled with 70 wt.% of the filler was two-times greater than that for the neat LDPE. The water absorption test revealed that the composites had a strong tendency to absorb water, which was dependent on the filler content. The experimental data were compared with several theoretical models.
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the mechanical and adhesive properties of electrically and thermally conductive polymeric composites based on high density polyethylene filled with nickel powder
Materials & Design, 2013Co-Authors: Volkan Cecen, Igor Krupa, Abderrahim Boudenne, Jan Prokes, I NovakAbstract:Abstract Electrically and thermally conductive composites made using high density polyethylene (HDPE) matrix blended with a special grade of branch-structured nickel particles were studied. Composites with high filler content were highly electrically and thermally conductive. The electrical conductivity of composites reached a value of 8.3 × 103 S m−1 when filled with 30 vol.% of the filler, and the thermal conductivity obtained using this filler content was found to be 1.99 W m−1 K−1. The percolation concentration of the filler within the HDPE matrix, which was determined from electrical conductivity measurements, was determined to be 8 vol.%. Young’s modulus of composites significantly increased from 606 MPa to 1057 MPa when composites were filled with 20 vol.% of the filler. Further increasing the filler content caused no further increase in Young’s modulus, probably due to high aggregation of the filler. The stress at break of the composites behaved nonlinearly; the low filler content suppressed necking, resulting in a decrease in stress at break, whereas higher filler content (higher than 10 vol.%) led to reinforcement of the composites and therefore increased the stress at break. The presence of nickel particles throughout the HDPE matrix increased the hydrophilicity of the composites. The contact angle of water on the neat HDPE decreased from 93° to 80° as the nickel content of the matrix was increased to 13 vol.% of nickel. Further increases in the filler content did not alter the contact angle. Similarly, the strength of the adhesive joint formed by the composite and aluminum foil increased from a value of 16 N m−1 for the neat HDPE to 27 N m−1 when the HDPE matrix was filled with 13 vol.% of the filler.
Bjorn Roth - One of the best experts on this subject based on the ideXlab platform.
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a comparative study on quality shelf life and sensory attributes of atlantic salmon slaughtered on board slaughter vessels against traditional land based facilities
Aquaculture, 2021Co-Authors: Maren Skare, Jorgen Lerfall, Sherry Stephanie Chan, Sigurd O Handeland, Trond Lovdal, Bjorn RothAbstract:Abstract The purpose of this study was to investigate the shelf life and quality of Atlantic salmon (Salmo salar) slaughtered onboard vessels and shipped to Denmark in −0.8 °C refrigerated seawater (RSW) as compared to traditional land-based slaughtering facilities having fish on ice. The quality and shelf life were measured on fresh and smoked Fillets including blood spot counting, Fillet gaping, texture hardness, microbiological counts, Quality Index Method (QIM) and sensory analysis. Blood spot counting and Fillet gaping were measured on smoked Fillets. Fresh fish slaughtered onboard the vessel had significantly lower Fillet gaping scores as compared to those slaughtered at the facility, while no difference was found on smoked Fillets. There were no significant differences in blood spots counts nor texture hardness between any of the groups. Salmon slaughtered on the vessel had a significant lower QIM score. The total mesophilic count and H2S producing bacteria for fish slaughtered onboard vessels were significant lower at the end of storage (21d). Sensory analysis after 18 days of storage revealed minimal differences between the groups, whereas fish from the vessel had lower protein precipitation. We conclude that fish slaughtered onboard vessels and transported in superchilled RSW onboard a slaughter vessel presents good quality and improves shelf life over time.
Sungseen Choi - One of the best experts on this subject based on the ideXlab platform.
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influence of filler type and content on properties of styrene butadiene rubber sbr compound reinforced with carbon black or silica
Polymers for Advanced Technologies, 2004Co-Authors: Sungseen Choi, Byungho Park, Hanjong SongAbstract:Rubber compounds are filled with reinforcing fillers to improve their physical properties. Carbon black and silica have different surface chemistries to each other. Differences in properties of carbon black- and silica-reinforced styrene-butadiene rubber (SBR) compounds were studied. Variation of properties of carbon black- or silica-filled compounds with the filler content was also investigated. The silica-filled compounds without any coupling agent and dispering agent were prepared to investigate the influence of polar materials-adsorption on the silica surface. Viscosity and crosslink density increased with increase of the filler content. Hardness, modulus, tensile strength, and wear property were improved more and more by increasing the filler content. Viscosity of the silica-filled compound was higher than that of the carbon black-filled one. Cure rate of the silica-filled compound became slower as the filler content increased, while that of the carbon black-filled one became faster. Difference in properties between the carbon black- and silica-filled compounds were explained by the poor silica dispersion and the adsorption of cure accelerator on the silica surface. Copyright © 2004 John Wiley & Sons, Ltd.
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properties of natural rubber composites reinforced with silica or carbon black influence of cure accelerator content and filler dispersion
Polymer International, 2003Co-Authors: Sungseen Choi, Byungwook JoAbstract:Filler dispersion is a critical factor in determining the properties of filled rubber composites. Silica has a high density of silanol groups on the surface, which lead to strong filler–filler interactions and a poor filler dispersions. A cure accelerator, N-tert-butyl-2-benzothiazole sulfenamide (TBBS), was found to improve filler dispersion in silica-filled natural rubber (NR) compounds. For the silica-filled NR compounds without the silane coupling agent, the reversion ratio generally increased with increase in TBBS content, whereas those of the silica-filled NR compounds containing the silane coupling agent and carbon black-filled NR compounds decreased linearly. The tensile strength of the silica-filled NR vulcanizate without the silane coupling agent increased as the TBBS content increased, whereas carbon black-filled samples did not show a specific trend. The experimental results were explained by TBBS adsorption on the silica surface and the improvement of silica dispersion with the aid of TBBS. Copyright © 2003 Society of Chemical Industry
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effect of filler filler interaction on rheological behaviour of natural rubber compounds filled with both carbon black and silica
Polymer International, 2003Co-Authors: Sungseen Choi, Changwoon Nah, Seung Goo Lee, Chang Whan JooAbstract:Rubber compounds are reinforced with fillers such as carbon black and silica. In general, filled rubber compounds show smooth rheological behaviour in measurement of Mooney viscosity or Mooney scorch time. Variation in rheological behaviour was studied in terms of the filler composition using natural rubber compounds filled with both carbon black and silica (carbon black/silica = 60/20,40/40, and 20/60 phr). The compound filled with carbon black/silica of 60/20 phr showed normal rheological behaviour. However, the compounds filled with carbon black/silica of 40/40 and 20/60 phr showed abnormal rheological behaviour, in which the viscosity increased suddenly and then decreased at a certain point during the measurement. The abnormal behaviour was explained by the strong filler–filler interaction of silica. Moreover, the abnormal rheological behaviour was displayed more clearly as the storage time of compounds is increased. © 2003 Society of Chemical Industry
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difference in bound rubber formation of silica and carbon black with styrene butadiene rubber
Polymers for Advanced Technologies, 2002Co-Authors: Sungseen ChoiAbstract:Formation of bound rubber is affected by the physical structure and surface chemistry of filler and the property of rubber. Variation of the bound rubber formation in styrene-butadiene rubber compounds filled with silica and/or carbon black was studied. Influence of temperature on extraction of loosely bound rubber was also investigated. For the both silica and carbon black-filled compounds, the bound rubber content increases with increase in the silica content ratio. The bound rubber content decreases with increasing the extracting temperature. The loosely bound rubber content of the silica-filled compound is higher than that of the carbon black-filled one. Activation energy for the extraction of the unbound and loosely bound rubbers becomes higher as the total filler content increases. The activation energy of the silica-filled compound is higher (almost double the value) than for the carbon black-filled one. Copyright© 2002 John Wiley & Sons, Ltd.
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influence of storage time and temperature and silane coupling agent on bound rubber formation in filled styrene butadiene rubber compounds
Polymer Testing, 2002Co-Authors: Sungseen ChoiAbstract:Abstract Bound rubber reflects the filler–polymer interactions involving physical adsorption, chemisorption, and mechanical interaction. For silica-filled rubber compounds, silane coupling agent is used to improve the filler dispersion. In the present work, variation of the bound rubber content with the storage time was studied using styrene–butadiene rubber (SBR) compounds filled with silica or carbon black. Influence of the silane content on the bound rubber formation was also investigated. The bound rubber content increases with increased storage time. The bound rubber content also increases with increase of the silane content. For the silica-filled compounds containing the silane, the bound rubber content increases dramatically at the beginning of storage. For the carbon black-filled compounds containing the silane, the bound rubber content increases notably over 20 days after the storage when the silane content is high. The bound rubber content also increases as the storage temperature increases. Increase of the bound rubber content by storage is explained by the formation of chemical bonds between the filler and rubber through the silane.
Jorgen Lerfall - One of the best experts on this subject based on the ideXlab platform.
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a comparative study on quality shelf life and sensory attributes of atlantic salmon slaughtered on board slaughter vessels against traditional land based facilities
Aquaculture, 2021Co-Authors: Maren Skare, Jorgen Lerfall, Sherry Stephanie Chan, Sigurd O Handeland, Trond Lovdal, Bjorn RothAbstract:Abstract The purpose of this study was to investigate the shelf life and quality of Atlantic salmon (Salmo salar) slaughtered onboard vessels and shipped to Denmark in −0.8 °C refrigerated seawater (RSW) as compared to traditional land-based slaughtering facilities having fish on ice. The quality and shelf life were measured on fresh and smoked Fillets including blood spot counting, Fillet gaping, texture hardness, microbiological counts, Quality Index Method (QIM) and sensory analysis. Blood spot counting and Fillet gaping were measured on smoked Fillets. Fresh fish slaughtered onboard the vessel had significantly lower Fillet gaping scores as compared to those slaughtered at the facility, while no difference was found on smoked Fillets. There were no significant differences in blood spots counts nor texture hardness between any of the groups. Salmon slaughtered on the vessel had a significant lower QIM score. The total mesophilic count and H2S producing bacteria for fish slaughtered onboard vessels were significant lower at the end of storage (21d). Sensory analysis after 18 days of storage revealed minimal differences between the groups, whereas fish from the vessel had lower protein precipitation. We conclude that fish slaughtered onboard vessels and transported in superchilled RSW onboard a slaughter vessel presents good quality and improves shelf life over time.
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effect of pancreas disease pd on quality attributes of raw and smoked Fillets of atlantic salmon salmo salar l
Aquaculture, 2012Co-Authors: Jorgen Lerfall, Sveinung Birkeland, Thomas Larsson, Torunn Taksdal, Paw Dalgaard, Sergei Afanasyev, Malfrid Tofteberg Bjerke, Turid MorkoreAbstract:Abstract The impact of pancreas disease (PD) on Fillet quality of raw and cold-smoked Atlantic salmon was investigated. Commercially reared fish were sorted into six groups: (1) Control (healthy fish), (2) SAV (infection with salmonid alphavirus, without PD outbreak), (3) PD0 (PD diagnosis at slaughter), (4) PD6 and (5) PD12 (diagnosed 5–7 and 11–12 months before slaughter, respectively) and (6) PDchronic (repeated PD outbreaks). The condition factor (CF) and Fillet protein content were significantly higher for the control group (1.13 and 22.1%, respectively). The CF was lowest for PDchronic (0.92), whereas the Fillet protein content was lowest in PD0 (20.2%). Fillet fat content did not vary significantly between the groups, but the muscle pH was 0.2 units higher in PD12 as compared to Control. Astaxanthin (Ax) and idoxanthin (Ix) content were significantly lowest for PD0. Ax recovered six months after the outbreak, but the Ix content remained lower in the PD affected salmon. The Ax level after smoking was similar for all groups, but Ix showed a similar pattern to that of raw Fillets. Results of the colorimetric analyses ( L *, a *, b *) indicated darkest colour for the control group and palest colour for PD0, whereas PDchronic showed highest differences between raw and smoked Fillets. Firmness of raw Fillets was lowest in PDchronic, but after smoking a significantly higher firmness was found in PDchronic, PD0 and PD6 (16.7–19.7 N) compared with that of Control and PD12 (14.1 N). Changes in Fillet quality in the order of their appearance were decreased CF, depleted muscle glycogen, increased drip loss of raw muscle, paler colour, depleted protein and finally harder texture in smoked salmon. It is concluded that the Fillet quality deteriorated after a PD outbreak, but the quality may to a large extent recover.
