Wood-based structure panels have been widely used in building construction, aerospace, and furniture industries, where adhesives bonding plays an essential role in the manufacturing processes. Formaldehyde-free adhesi...
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Wood-based structure panels have been widely used in building construction, aerospace, and furniture industries, where adhesives bonding plays an essential role in the manufacturing processes. Formaldehyde-free adhesive resins are in high demand to meet the increasingly stringent environmental regulations and have sparked enormous research interest. This work reports a systematic investigation of bonding behavior of a pMDI adhesive delivered as a water/pMDI emulsion and used as a model system to investigate the adhesive penetration depth and resulting bonding strength when used as an adhesive to bond wood plies. The approach of water/pMDI emulsion can avoid a water distribution problem which has to be considered in a traditional procedure for bonding wood materials. The stability and phase separation of the water/pMDI emulsion system were first examined by image analysis and viscosity measurements as well as the effects of the emulsion composition on the bonding strength of the adhesive. By both the pull-off and lap-shear tests, it was determined that a water content around 30% by weight of the emulsion was providing optimum strength while yielding emulsions stable enough to be practically applied on wood surfaces. After this optimization, the adhesive penetration depth was altered by treating the wood surface with a silane agent (APTES) so as to improve the bonding strength. The results show that a moderate penetration helps enhance bonding strength, providing insights into the nonproportional relationship between adhesive penetration and bonding strength.
The lithologic oil reservoir of ES, in Luojia area in Zhanhua sag is formed by underwater alluvial fan andturbidite fan sandbody. It is a new oil-bearing series that has just found in recent years in this area. Thedis...
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The lithologic oil reservoir of ES, in Luojia area in Zhanhua sag is formed by underwater alluvial fan andturbidite fan sandbody. It is a new oil-bearing series that has just found in recent years in this area. Thedistribution and accumulation of oil and gas are complex because of the varied thickness of sandbody andcomplex structures. The sedimentary factes-control factor of oil reservoir and accumulation conditions arestudied and the distribution rule of oil and gas in ES3 in this area is summarized according to the researchon structure and reservoir, analysis of seismic factes and sandbody trace technique, it has gotten someachievements and experiences in the progressive exploration and development. It is thought that the oilsource is full, properties of reservoir and cap rock are favorable, and conditions of migration, trap,accumulation are good. It is the main exploration area in the short term, and it is also main target anddirection in the future.
Curcuma longa L. (turmeric), Beta vulgaris L. (beetroot), and Daucus carota L. (carrot) grown in Bangladesh were analyzed for nutritional and phytochemical contents to reveal their comparative nutritional compositions...
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Curcuma longa L. (turmeric), Beta vulgaris L. (beetroot), and Daucus carota L. (carrot) grown in Bangladesh were analyzed for nutritional and phytochemical contents to reveal their comparative nutritional compositions and antiradical properties. Ash, protein, and carbohydrate content were significantly preeminent in beetroot as compared to others. Whereas fat content was found to be high in turmeric, carrots contained a great percentage of crude fiber. Beetroot was shown to have much greater potassium, calcium, and iron levels than others. Regarding amino acids, glutamic acid was found to be greater in beetroot and carrot whereas turmeric had significantly high aspartic acid content. Leucine had the highest concentration among essential amino acids in these three samples. Total antioxidant activity, total flavonoids, and phenolic contents in the methanolic extract of turmeric were found to be substantially higher than in beetroot and carrot. Furthermore, the extract of turmeric (IC50 value: 13.46 mu g/mL) scavenged 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) free radicals considerably to a greater extent than beetroot (IC50 value: 380.61 mu g/mL) and carrot (IC50 value: 1252.85 mu g/mL). A positive correlation was found between the phytochemical contents and antiradical activity. The information from this study will help to find the potential ingredients from these plants for functional food.
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