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排序方式: 共有910条查询结果,搜索用时 31 毫秒
41.
Amorn Chaiyasat Sirinard Jearanai Lew P Christopher Md Nur Alam 《Polymer International》2019,68(1):102-109
A novel process for the production of superabsorbent materials (hydrogels) from bacterial cellulose (BC) was developed. Prior to crosslinking with a water‐soluble polyethylene glycol diacrylate (PEGDA), BC was first carboxymethylated and functionalized with glycidyl methacrylate. The degree of crosslinking influenced the swelling properties of the hydrogels. The use of greater amounts of PEGDA enhanced the formation of a thicker macromolecular network containing fewer capillary spaces in the crosslinked gel. The maximum water retention value of the hydrogels containing 2.5–3.5 mmol of carboxyl groups per gram of gel reached 125 g g?1 in distilled water, and 29 g g?1 in saline (0.9% NaCl solution). The highly porous hydrogel architecture with a pore size of 350–600 µm created a high specific surface area. This enables rapid mass penetration in superabsorbent applications. The superabsorbent hydrogels reached 80% of their maximum water absorption capacity in 30 min. © 2018 Society of Chemical Industry 相似文献
42.
Nur Hawa Nabilah Azman Md Shuhazlly Mamat @ Mat Nazir Lim Hong Ngee Yusran Sulaiman 《国际能源研究杂志》2018,42(6):2104-2116
The research on electrode materials for supercapacitor application continues to evolve as the request of high‐energy storage system has increased globally due to the demand for energy consumption. Over the past decades, various types of carbon‐based materials have been employed as electrode materials for high‐performance supercapacitor application. Among them, graphene is 1 of the most widely used carbon‐based materials due to its excellent properties including high surface area and excellent conductivity. To exploit more of its interesting properties, graphene is tailored to produce graphene oxide and reduced graphene oxide to improve the dispersibility in water and easy to be incorporated with other materials to form binary composites or even ternary composites. Nowadays, ternary composites have attracted enormous interest as 2 materials (binary composites) cannot satisfy the requirement of the high‐performance supercapacitor. Thus, many approaches have been employed to fabricate ternary composites by combining 3 different types of electroactive materials for high‐performance supercapacitor application. This review focuses on the supercapacitive performance of graphene‐based ternary composites with different types of active materials, ie, conducting polymers, metal oxide, and other carbon‐based materials. 相似文献
43.
Anomaly localization in regular textures based on deep convolutional generative adversarial networks
Oz Muhammed Ali Nur Mercimek Muharrem Kaymakci Ozgur Turay 《Applied Intelligence》2022,52(2):1556-1565
Applied Intelligence - Pixel-level anomaly localization is a challenging problem due to the lack of abnormal training samples. The existing adversarial network methods attempt to segment anomalies... 相似文献
44.
Siti Norhamimah Mohamed Yunus Faridah Abas Ahmad Haniff Jaafar Awanis Azizan Nur Khaleeda Zulaikha Zolkeflee Siti Zulaikha Abd Ghafar 《Food science and biotechnology》2021,30(2):195
The 70% ethanolic extracts from eight neglected fruits; Muntingia calabura, Leucaena leucocephala, Spondias dulcis, Syzygium jambos, Mangifera caesia, Ardisia elliptica, Cynometra cauliflora and Ficus auriculata were evaluated for their 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging, α-glucosidase inhibitory activities as well as total phenolic content. The results of this study revealed that M. caesia fruit extract demonstrated the most potent radical scavenging activity. Among the fruits examined for α-glucosidase inhibitory activity, M. calabura and F. auriculata exhibited strong activity with no significant difference. The Pearson correlation indicated that the activities of M. caesia and F. auriculata contributed by phenolic compounds. A total of 65 metabolites were tentatively identified by using ultra-high-performance liquid chromatography tandem mass spectrometry (UHLPC-MS/MS). These findings suggested that the possible application of M. caesia and F. auriculata as a functional food with antioxidant and α-glucosidase inhibitory properties. 相似文献
45.
Esma Nur Cinicioglu Şule Önsel Füsun Ülengin 《Expert systems with applications》2012,39(12):10923-10932
The purpose of this study is to analyze the relations between the factors that enable national competitive advantage and the establishment of competitive superiority in automotive industry through a comprehensive analytical model. Bayesian networks (BN) are used to investigate the associations of different factors in the automotive industry which lead to competitive advantage. The results of the study focus on building a road map for the automotive sector policy makers in their way to improve the competitiveness through scenario analysis. Using the probabilistic dependency structure of the Bayesian network all of the variables in the model can be estimated. Thus, with the proposed model the automotive industry can be analyzed as a whole system and not only in terms of single variables. Findings of the model indicate that technological developments in automotive industry can alter the nature of competition in this industry. 相似文献
46.
Selçuk Bilgen 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2016,38(9):1286-1292
The purpose of this study is to evaluate the chemical exergy (ECH) of liquid products obtained from fast pyrolysis of biomass. I have calculated the chemical exergy values from a formula in literature and have developed a formula for estimating the chemical exergy of biomass from the higher heating value and their ultimate analysis values. The mean differences between these values range from –0.391% to 0.460%. The formula developed for estimating the chemical exergy of biomass from the higher heating value and their ultimate analyses had a correlation coefficient (R2 = 0.9999), and the prediction of this formula is good. The goal is to identify desirable attributes that may serve as the basis for decision-making for future biofuel options. Studies on the pyrolytic oils showed that the oils obtained from chestnut cupulae and maple fruit can be used as a renewable fuel and chemical feedstock. 相似文献
47.
Nur Fatihah Mohd Yatim Masitah Abd. Rahim Kavitha Menon Faisal Muti Al-Hassan Rahimah Ahmad Anita Bhajan Manocha Mohamed Saleem Badrul Hisham Yahaya 《International journal of molecular sciences》2014,15(5):8835-8845
Both α- and β-thalassaemia syndromes are public health problems in the multi-ethnic population of Malaysia. To molecularly characterise the α- and β-thalassaemia deletions and mutations among Malays from Penang, Gap-PCR and multiplexed amplification refractory mutation systems were used to study 13 α-thalassaemia determinants and 20 β-thalassaemia mutations in 28 and 40 unrelated Malays, respectively. Four α-thalassaemia deletions and mutations were demonstrated. −−SEA deletion and αCSα accounted for more than 70% of the α-thalassaemia alleles. Out of the 20 β-thalassaemia alleles studied, nine different β-thalassaemia mutations were identified of which βE accounted for more than 40%. We concluded that the highest prevalence of (α- and β-thalassaemia alleles in the Malays from Penang are −−SEA deletion and βE mutation, respectively. 相似文献
48.
The anti-inflammatory effects of Acanthopanax senticosus leaves (ASL) and the effects of extrusion were evaluated. ASL exhibited in vitro and in vivo antiinflammatory activities in experimental systems. Extrusion increased the effect of ASL. ASL reduced C48/80-induced histamine release from HMC-1 cells as well as in vivo model, suggesting that ASL induces mast cell stabilization and has an anti-histamine activity. The effects of ASL and extruded ASL (ASLE) on pro-inflammatory cytokine production were evaluated. ASL treatment reduced MCP- 1, TNF-α, and IL-1β mRNA expressions and decreased their protein levels in HMC-1 cells. Decreases in serum NO, MDA, and TNF-α levels were observed in acute inflammatory rats, and extrusion increased the effects of ASL in a dose-dependent manner. These data support pharmacological basis of ASL and the effect of extrusion for future treatment of inflammation. 相似文献
49.
Hamizah Md Rasid Nur Hanis Adila Azhar Siti Fairus M. Yusoff 《Journal of Polymer Research》2017,24(7):106
The modification of liquid natural rubber (LNR) has attracted interests among chemists as it brings improvements to several of its properties and widens its application to various fields. LNR can be modified into fluorinated LNR (F-LNR) which is of interest to industries due to its remarkable properties, including low surface energies, high thermal stabilities, together with its significant hydrophobic characters. In this work, a new route to prepare fluorinated rubber was presented. Hydroxylated LNR (OH-LNR) was initially synthesized in good yield via oxidation in the presence of tungsten complex catalyst and acetic acid with hydrogen peroxide as an oxidant. The optimum hydroxyl content of 57.0% was obtained within 6 h reaction time at 90 °C. In the second step, the esterification of OH-LNR using pentadecafluorooctanoyl chloride (PDFOC) under mild conditions was conducted, leading to LNR bearing fluoro groups in the side chain of LNR (F-LNR). ATR-FTIR spectroscopy was used to elucidate the structure and determine any changes in the functional groups that may have been induced during the reaction. 1H NMR spectroscopy was employed to reveal that a high fluorine content of 48.6% was obtained using 3:1 molar ratio of OH-LNR:PDFOC for 8 h at 50 °C. The microstructure of F-LNR was further analyzed using 19F NMR and 13C NMR spectroscopies, and the results confirmed the presence of fluorine in LNR. Thermogravimetric analyses also indicated that the modification improved thermal stability of the LNR. Contact angle measurements were also conducted to verify the hydrophobicity of the fluorinated rubber and the results obtained showed that F-LNR exhibited higher hydrophobicity than LNR. 相似文献
50.
Selçuk Kılınç Gökhan Çabuk 《International Journal of Circuit Theory and Applications》2015,43(3):390-400
In power electronics, the switching elements are controlled by pulse width modulated (PWM) signals making their currents on and off repeatedly. This might cause electromagnetic interference (EMI) problems especially in switched mode power supplies. One method for mitigating the EMI is to use the frequency modulation technique in the control signal of the switching metal–oxide–semiconductor field‐effect transistor. According to this approach, frequency of the PWM signal is modulated in order to spread its spectrum and hence reduce the EMI levels. This paper presents the theoretical analysis for the spectrum of a frequency modulated PWM signal. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献