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81.
A New Class of Renewable Thermoplastics with Extraordinary Performance from Nanostructured Lignin‐Elastomers 下载免费PDF全文
Chau D. Tran Jihua Chen Jong K. Keum Amit K. Naskar 《Advanced functional materials》2016,26(16):2677-2685
A new class of thermoplastic elastomers has been created by introducing nanoscale‐dispersed lignin (a biomass‐derived phenolic oligomer) into nitrile rubber. Temperature‐induced controlled miscibility between the lignin and the rubber during high shear melt‐phase synthesis allows tuning the material's morphology and performance. The sustainable product has unprecedented yield stress (15–45 MPa), strain hardens at large deformation, and has outstanding recyclability. The multiphase polymers developed from an equal‐mass mixture of a melt‐stable lignin fraction and nitrile rubber with optimal acrylonitrile content, using the method described here, show 5–100 nm lignin lamellae with a high‐modulus rubbery interphase. Molded or printed elastomeric products prepared from the lignin‐nitrile material offer an additional revenue stream to pulping mills and biorefineries. 相似文献
82.
Spectral domain analysis is used to determine the end effects in coupled rectangular slot resonators in unilateral fin lines. End corrections computed as a function of the structural parameters are reported. 相似文献
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84.
The rate sensitivity of multiple obstacle aluminium alloy system was measured using the stress relaxation method. A discrepancy was observed between the slope of the Haasen plot (rate sensitivity of dislocation–dislocation interaction) in pure metals and in alloys strengthened by multiple obstacles. Considering a simplifying assumption of the constant obstacle force–distance profile, it is suggested that slope of the Haasen plot is governed by glide dislocations’ length taking part in a thermally activated event. The relative strength and spacing of obstacles (forest dislocations, solutes and precipitates) is proposed to affect the thermally activated dislocation length, which in turn manifests as the difference in slope of the Haasen plot. 相似文献
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86.
A simple procedure to determine the non-linear in-plane lamina shear response of laminated composites is presented. Using the ±45° symmetric laminate tensile test results, in conjunction with computational micromechanics, a method was developed and validated to characterize the lamina shear response and the in-situ matrix shear response. Load, and axial and transverse strains measured in the tests were used to calculate the non-linear shear stress–shear strain response of the composite. From this result, the in-situ matrix equivalent stress–strain response was obtained, with some simplifying assumptions, and subsequently used in a micromechanics-based representative finite element (FE) model of the ±45° symmetric laminate tensile test to determine the accuracy of the non-linear response of the in-situ matrix. Results from the FE model of a representative cell (RC) that depicts fiber diameter, fiber volume fraction (Vf) and angled fiber packing of the ±45° symmetric laminate were found to match the tests result well. Thus, the procedure to extract the non-linear lamina shear response and the non-linear in-situ matrix response from the ±45° symmetric laminate tensile test was validated. 相似文献
87.
Fawaz Alsolami Abdullah Saad Al-Malaise Alghamdi Asif Irshad Khan Yoosef B. Abushark Abdulmohsen Almalawi Farrukh Saleem Alka Agrawal Rajeev Kumar Raees Ahmad Khan 《计算机、材料和连续体(英文)》2022,73(2):2591-2618
The COVID-19 pandemic has triggered a global humanitarian disaster that has never been seen before. Medical experts, on the other hand, are undecided on the most valuable treatments of therapy because people ill with this infection exhibit a wide range of illness indications at different phases of infection. Further, this project aims to undertake an experimental investigation to determine which treatments for COVID-19 disease is the most effective and preferable. The research analysis is based on vast data gathered from professionals and research journals, making this study a comprehensive reference. To solve this challenging task, the researchers used the HF AHP-TOPSIS Methodology, which is a well-known and highly effective Multi-Criteria Decision Making (MCDM) technique. The technique assesses the many treatment options identified through various research papers and guidelines proposed by various countries, based on the recommendations of medical practitioners and professionals. The review process begins with a ranking of different treatments based on their effectiveness using the HF-AHP approach and then evaluates the results in five different hospitals chosen by the authors as alternatives. We also perform robustness analysis to validate the conclusions of our analysis. As a result, we obtained highly corroborative results that can be used as a reference. The results suggest that convalescent plasma has the greatest rank and priority in terms of effectiveness and demand, implying that convalescent plasma is the most effective treatment for SARS-CoV-2 in our opinion. Peepli also has the lowest priority in the estimation. 相似文献
88.
Agrawal A Park HS Nathoo S Gieg LM Jack TR Miner K Ertmoed R Benko A Voordouw G 《Environmental science & technology》2012,46(2):1285-1292
Souring in the Medicine Hat Glauconitic C field, which has a low bottom-hole temperature (30 °C), results from the presence of 0.8 mM sulfate in the injection water. Inclusion of 2 mM nitrate to decrease souring results in zones of nitrate-reduction, sulfate-reduction, and methanogenesis along the injection water flow path. Microbial community analysis by pyrosequencing indicated dominant community members in each of these zones. Nitrate breakthrough was observed in 2-PW, a major water- and sulfide-producing well, after 4 years of injection. Sulfide concentrations at four other production wells (PWs) also reached zero, causing the average sulfide concentration in 14 PWs to decrease significantly. Interestingly, oil produced by 2-PW was depleted of toluene, the preferred electron donor for nitrate reduction. 2-PW and other PWs with zero sulfide produced 95% water and 5% oil. At 2 mM nitrate and 5 mM toluene, respectively, this represents an excess of electron acceptor over electron donor. Hence, continuous nitrate injection can change the composition of produced oil and nitrate breakthrough is expected first in PWs with a low oil to water ratio, because oil from these wells is treated on average with more nitrate than is oil from PWs with a high oil to water ratio. 相似文献
89.
Ram Swaroop Verma Rajendra Chandra Padalia Amit Chauhan 《Journal of the science of food and agriculture》2012,92(3):626-631
BACKGROUND: Two Ocimum basilicum cultivars, ‘Vikarsudha’ and ‘CIM‐Saumya’, grown in the Kumaon region of western Himalaya were evaluated for their essential oil yield and composition at different stages of plant growth during two distinct cropping seasons (spring–summer and rain–autumn). RESULTS: The highest yield of essential oil was obtained at full bloom stage in both cultivars in both cropping seasons. The essential oils obtained from different stages in two cropping seasons were analysed by capillary gas chromatography with flame ionisation detection, and gas chromatography–mass spectrometry. The major component of cultivar ‘Vikarsudha’ was methyl chavicol (84.3–94.3%), while for cultivar ‘CIM‐Saumya’ the main components were methyl chavicol (62.5–77.6%) and linalool (14.4–34.1%). CONCLUSION: This study clearly indicated that cultivar, cropping season, plant ontogeny and plant part had significant effects on the yield and quality of the essential oil of O. basilicum. Further, the amount of methyl chavicol in the cultivars grown in this region was higher than in cultivars from other parts of India. Copyright © 2011 Society of Chemical Industry 相似文献
90.
Nanocomposite Hydrogel Materials for Defective Cartilage Repair and Its Mechanical Tribological Behavior—A Review 下载免费PDF全文
Osteoarthritis (OA) is a regressive ailment that affects a large population of patients. The most common symptoms of OA in humans are cartilage abnormalities. Hydrogels are excellent candidates for cartilage regeneration and are widely accepted as implants. In the past few decades, numerous types of hydrogels have been synthesized to repair cartilage defects. This study highlights recent advances in hydrogel development for the treatment of cartilage defects. In addition, the detailed progression of tailored nanocomposite hydrogels is summarized, and emphasis has been placed on the mechanical properties, especially the tribological behavior of the developed nanocomposite hydrogels. 相似文献