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41.
A one‐step method was used to prepare stable aqueous nanocomposite dispersions based on cellulose whiskers extracted from the rachis of the date palm tree and a poly(styrene‐co‐2‐ethyl hexylacrylate) copolymer via miniemulsion polymerization. A reactive silane, i.e., methacryloxypropyl triethoxysilane was added to stabilize the dispersion and favor the anchoring of the whiskers on polymer particles. Dynamic light scattering was used to study the effect of the silane and whiskers contents on the average particle size of the polymer. Nanocomposites materials were prepared from these dispersions using a casting/evaporation method. The effect of the silane and whiskers contents on the thermal and mechanical properties were studied using differential scanning calorimetry and dynamic mechanical analysis. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers  相似文献   
42.
Electrical capacitance tomography (ECT) was utilized for monitoring of high-shear mixing and high-shear granulation processes. A finite element method (FEM)-based reconstruction algorithm was utilized to take into account the specific geometrical characteristics of the experimental set-up. Two-dimensional ECT tomograms, mixing index curves and permittivity fractions were computed based on the measurements, and their suitability in the analysis of the processes was assessed. It was found that the different mixing processes and the different granulation processes could be analyzed based on these quantities.  相似文献   
43.
This paper presents the first investigation on the effect of enrichment refined olive oil by chlorophyll pigment extracted from Chemlali olive leaves during storage (6 months). The changes that occurred in the quality indices, fatty acids, sterol, and phenolic content were investigated during the storage of refined olive oil under RT (20°C) and accelerated conditions (50°C) in the dark. Additionally, the pigments (chlorophyll and carotene) changes during 6 months of oil storage were evaluated. At the end of the storage, more than 90% of chlorophyll pigments decomposed in all samples, while, carotene pigment loss was lower showing up to 60 and 85% loss for oil stored at 20 and 50°C, respectively, at the end of storage. The reduction of total phenolic compounds exhibited similar degradation profiles, being reduced by 5% and up to 60% for the enriched refined olive oil stored at 20 and 50°C in 6 months, respectively. In the fatty acid composition, an increase in oleic acid and a decrease in linoleic and linolenic acids were less significant in enriched than non‐enriched refined olive oil. On the other hand, sterol composition was less affected by storage in enriched oil samples. However, the sterol concentration of the oil samples showed an increase in β‐sitosterol, 24‐methylene cholesterol, stigmasterol, and a decrease in cholesterol, Δ5, 24‐stigmastadienol percentage at the end of storage. Based on the Rancimat method, the oils with added leaf pigment extract had the lowest peroxide value and the highest stability. After 6 months of storage, the oxidative resistance of refined olive oil fell to 0.2 and to zero for enriched refined olive oil stored at 20 and 50°C, respectively.  相似文献   
44.
Cytosolic phospholipase A2α (cPLA2α) may play a critical role in neuropsychiatric and neurodegenerative disorders associated with oxidative stress and neuroinflammation. An effective PET radioligand for imaging cPLA2α in living brain might prove useful for biomedical research, especially on neuroinflammation. We selected four high‐affinity (IC50 2.1–12 nm ) indole‐5‐carboxylic acid‐based inhibitors of cPLA2α, namely 3‐isobutyryl‐1‐(2‐oxo‐3‐(4‐phenoxyphenoxy)propyl)‐1H‐indole‐5‐carboxylic acid ( 1 ); 3‐acetyl‐1‐(2‐oxo‐3‐(4‐(4‐(trifluoromethyl)phenoxy)phenoxy)propyl)‐1H‐indole‐5‐carboxylic acid ( 2 ); 3‐(3‐methyl‐1,2,4‐oxadiazol‐5‐yl)‐1‐(2‐oxo‐3‐(4‐phenoxyphenoxy)propyl)‐1H‐indole‐5‐carboxylic acid ( 3 ); and 3‐(3‐methyl‐1,2,4‐oxadiazol‐5‐yl)‐1‐(3‐(4‐octylphenoxy)‐2‐oxopropyl)‐1H‐indole‐5‐carboxylic acid ( 4 ), for labelling in carboxyl position with carbon‐11 (t1/2=20.4 min) to provide candidate PET radioligands for imaging brain cPLA2α. Compounds [11C] 1 – 4 were obtained for intravenous injection in adequate overall yields (1.1–5.5 %) from cyclotron‐produced [11C]carbon dioxide and with moderate molar activities (70–141 GBq μmol?1) through the use of Pd0‐mediated [11C]carbon monoxide insertion on iodo precursors. Measured logD7.4 values were within a narrow moderate range (1.9–2.4). After intravenous injection of [11C] 1 – 4 in mice, radioactivity uptakes in brain peaked at low values (≤0.8 SUV) and decreased by about 90 % over 15 min. Pretreatments of the mice with high doses of the corresponding non‐radioactive ligands did not alter brain time–activity curves. Brain uptakes of radioactivity after administration of [11C] 1 to wild‐type and P‐gp/BCRP dual knock‐out mice were similar (peak 0.4 vs. 0.5 SUV), indicating that [11C] 1 and others in this structural class, are not substrates for efflux transporters.  相似文献   
45.
In this study, laser treatment of sintered SiC surfaces is carried out to enhance the surface hydrophobicity. Morphological and metallurgical changes of the treated surfaces are evaluated using optical and scanning electron microscopy, energy dispersive spectroscopy, and x-ray diffraction (XRD). Microhardness and fracture toughness are measured using indentation tests. The residual stresses present are determined using the XRD technique. The wetting characteristics of the treated surfaces are assessed through contact angle measurements. It is found that the laser-treated surfaces consist of fine grooves and pillars and that the resulting surface roughness enhances the surface hydrophobicity. The fracture toughness of the treated surface is reduced possibly because of the microhardness increase at the surface. The residual stress formed in the surface region is on the order of 1.8 GPa, and it is compressive.  相似文献   
46.
Many eco design tools and product assessment methods have been developed to improve the environmental performance of products during design stage. Despite the efforts made at the product level, environmental impact in our society is increasing due to environmental impact associated with increased product volume. This article presents a new methodology for product life cycle design assessment to predict the total impact caused in the society by forecasting the market growth of emerging product technologies. A number of products were used to prove the validity of the proposed model and demonstrate the usefulness of the methodology.  相似文献   
47.
This research aims to study the effect of ammonium polyphosphate and expandable graphite on the intumescent coating formulations (ICF). The coating presented in this research article is based on carbon source expandable graphite (EG), blowing agent melamine, acid source ammonium polyphosphate (APP), epoxy resin as a binder with polyamide amine. The stability of the developed coating was verified at 950°C for 1-hour fire test. The results showed that the coating is stable and well bond with the steel substrate. The char was characterized by using FESEM, XRD, FTIR, DTA, TGA, XPS, Py-GCMS and Weathering Test. The morphology of the char was studied by SEM of the coating after furnace fire test. XRD and FTIR show the presence of graphite, borophosphate; boron oxide and sassolite in the residual char. TGA and DTG disclosed that EG improved the residual mass of coating. XPS analysis showed the char residue of IF5-APP-EG contains carbon and oxygen contents 47.50 and 40.70, respectively. Py-GCMS analysis described that the IF5-APP-EG released less gaseous compounds. The weathering test illustrated that's the char expansion of coatings samples was decreased due to the presence of a humid environment and UV light. The IF5-APP-EG showed the maximum char expansion, lower substrate temperature and high residual weight among the studied formulations.  相似文献   
48.
Disassembly is a critical step to increase the value of end-of-life (EOL) products and to reduce the environmental footprint. Despite worldwide efforts, disassembly is still performed manually due to the uncertainty associated with the quality and the quantity of the returned EOL products. In this paper, a cognitive robotics based system is proposed to address this problem. The system is equipped with four cognitive functions: reasoning, execution monitoring, learning and revision. The proposed system is tested using LCD screens. The results show that the system is flexible enough to deal with any product models without prior information.  相似文献   
49.
In the context of water as an economic good, from the use of water, one can derive a value, which can be affected by the reliability of supply. On-demand irrigation systems provide valuable water to skilled farmers who have the capacity to maximize economic value of water. In this study, simultaneous optimization of on-demand irrigation network layout and pipe sizes is considered taking into account both investment and annual energy costs. The optimization problem is formulated as a problem of searching for the upstream head value, which minimizes the total cost (investment and energy costs) of the system. The investment and annual energy costs are obtained in two separate phases. Max–Min ant system (MMAS) algorithm is used to obtain the minimum cost design considering layout and pipe diameters of the network simultaneously. Clement methodology is used to determine flow rates of pipelines at the peak period of irrigation requirements. The applicability of the proposed method is showed by re-designing a real world example from literature.  相似文献   
50.
The objective of this study was to evaluate the effect of Protexin (Probiotics International Ltd., South Petherton, UK) in the prevention of ileocecal infection by Mycobacterium avium ssp. paratuberculosis (MAP) in dairy calves in the field situation. Forty Holstein bull calves whose dams were paratuberculosis negative (confirmed by serum ELISA test and fecal nested PCR) were randomly selected in 2 groups. All calves were fed raw milk collected from the bulk tank in a paratuberculosis-infected dairy farm, which was confirmed by PCR. The treatment group (20 calves) was given 2 g of Protexin from birth until weaning (90 d). The control group (20 calves) did not consume Protexin. The calves were culled at 12 mo of age and the ileocecal lymph nodes were sampled. The lymph nodes were tested by nested PCR to evaluate MAP infection. In the treatment group, 2 out of 20 calf (10%) ileoceca were infected by MAP, whereas in the control group, 8 out of 20 calf (40%) ileoceca were infected by MAP. A significant difference existed between ileocecal infection by MAP in treatment and control groups. Thus, Protexin showed a significant effect in decreasing the ileocecal infection by MAP.  相似文献   
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