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991.
Self‐compacting concrete (SCC) was developed in 1988 and introduced by Professor H. Okamura to achieve durability of structures with low skilled laborers. The three properties of SCC that differentiates it from traditional concrete are passing ability, filling ability and segregation resistance. The present study highlights the developments concerning SCC in the period from 1995 to 2017. This information is important for researchers and professionals working in this area. SCC can be optimized to a larger extent to find the best alternative either by use of additives or tailor‐made mix design. Based on different principles and parameters, design methods can be categorized into six classes namely empirical design method, statistical factorial design method, strength‐based design method, rheology of paste method, particle packing method and Eco‐SCC mixture design method. To develop SCC with high quality a suitable method can be chosen depending upon the situation and application. 相似文献
992.
In this study, crosslinking of poly(vinyl alcohol) (PVA) with tartaric acid, as crosslinker, is performed using microwave irradiation. A comparison between the properties of PVA crosslinked using microwave irradiation and conventional heating methods is also discussed. While the water absorption, tensile and thermal properties of PVA crosslinked by either of the methods are comparable, microwave irradiation took only one‐eighth (14 min) of the time compared to conventional heating. In comparison with PVA (42 MPa), the strength of PVA crosslinked with 35% TA increased to 145 and 153 MPa for conventional heating and microwave irradiation, respectively. Water absorption of crosslinked PVA film is successively reduced to less than 30% in comparison with PVA (～200%). Moreover, the crosslinked films are stable at higher temperatures in comparison with PVA. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46125. 相似文献
993.
Senthil Nagappan Sanjay Kumar Verma 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2018,40(24):2933-2940
Microalgae are a potential source of biofuel and nutraceuticals. In the present study, Desmodesmussp. MCC34 was identified as a promising species for biodiesel and omega-3 fatty acid productions after initial screening since it had displayed the highest lipid productivity of 15.9 mg L?1 day?1 and alpha-linolenic acid of 24% of total fatty acids. Using silver ion chromatography, 92% of pure alpha-linolenic acid was selectively removed from total lipid of Desmodesmussp. MCC34, while the residual oil having a higher amount of saturated and monounsaturated fatty acids displayed biodiesel property adhering to international standards, suggesting fuel co-application.Abbreviations: ALA: alpha-linolenic acid methyl ester; GLAME: gamma-linolenic acid methyl ester; FAME: atty acid methyl ester; SFA: aturated fatty acid; MUFA: monounsaturated fatty acid; PUFA: polyunsaturated fatty acid. 相似文献
994.
The variance is a statistical measure widely used in many real-life application areas. This article makes an extensive investigation on variance measure in the case when the uncertainty is not of a probabilistic nature. It generalizes the notion of variance as well as the theory of ordered weighted aggregation operators. First, we extend the idea of representative value/expected value of a decision maker and develop some new deviation measures based on ordered weighted geometric (OWG) average and ordered weighted harmonic average (OWHA) operators. These measures are developed with the consideration that decision maker can represent his/her attitudinal expected value by using any one of the ordered weighted aggregation (OWA) operators. Further, this study proposes some deviation measures by using the generalized-OWA (GOWA) and Quasi-OWA as an expected value of decision maker and discusses their particular cases. Second, a number of generalized deviation measures are introduced by taking the generalized arithmetic mean and quasi-arithmetic means for aggregation of the individual dispersion. This approach provides an ability to the user for considering the deviation under different realistic-scenario. These measures lead to many interesting particular and limiting cases and enrich the use of ordered weighted aggregation operators in the variance. 相似文献
995.
Krishnendu Sarkar Mozakkar Hossain Pooja Devi K. D. M. Rao Praveen Kumar 《Advanced Materials Interfaces》2019,6(20)
The development of self‐powered and broadband (NIR–Vis–UV) photodetectors with high responsivity is essential for energy efficient futuristic optoelectronic devices. A simple approach is reported to formulate inorganic–organic (GaN/rGO: Ag NP) hybrid p–n heterojunction photodetectors clasping with transparent Au nanowire network as the top electrode. The heterojunction demonstrates excellent rectification ratio of 105 and broadband photoresponse due to GaN in ultraviolet (UV) region and silver‐loaded reduced graphene oxide (rGO: Ag NP) in visible to infrared region. Further, the reducing effect of Ag nanoparticles (Ag NPs) to GO along with its localized surface plasmon resonance is utilized to enhance the response in near infrared (NIR) and the visible region in the presented device structure. Transparent Au nanowire network works as an efficient charge collector ensuing high responsivity and fast switching characteristics. The heterojunction exhibits superior photoresponse with high on/off ratio (104), responsivity (0.266 A W‐1), and detectivity of (2.62 × 1011), under the illumination of 360 nm light. Due to the high built‐in‐potential difference at the heterojunctions, self‐powered operation is demonstrated under entire excitation wavelength (360–980 nm) range, which holds great futuristic promises for cost‐effective, stable, and efficient energy conserving electronics. 相似文献
997.
Clean Technologies and Environmental Policy - Development of environmentally benign green processes for utilization of carbon dioxide to synthesize value-added compounds using heterogeneous... 相似文献
998.
Deepika Singh Vikas Kumar Ekta Yadav Neha Falls Manvendra Singh Ujendra Komal Amita Verma 《IET nanobiotechnology / IET》2018,12(6):748
Facile green synthesis of silver nanoparticles (AgNPs) using an aqueous extract of Carissa carandas (C. carandas) leaves was studied. Fabrication of AgNPs was confirmed by the UV–visible spectroscopy which gives absorption maxima at 420 nm. C. carandas leaves are the rich source of the bioactive molecules, acts as a reducing and stabilising agent in AgNPs, confirmed by Fourier transforms infrared spectroscopy. The field emission scanning electron microscope revealed the spherical shape of biosynthesised AgNPs. A distinctive peak of silver at 3 keV was determined by energy dispersive X‐ray spectroscopy. X‐ray diffraction showed the facecentred cubic structure of biosynthesised AgNPs and thermal stability was confirmed by the thermogravimetric analysis. Total flavonoid and total phenolic contents were evaluated in biosynthesised AgNPs. Biosynthesised AgNPs showed free radical scavenging activities against 2, 2‐diphenyl‐1‐picrylhydrazyl test and ferric reducing antioxidant power assay. In vitro cytotoxicity against hepatic cell lines (HUH‐7) and renal cell lines (HEK‐293) were also assessed. Finally, biosynthesised AgNPs were scrutinised for their antibacterial activity against methicillin‐resistant Staphylococcus aureus, Shigella sonnei, Shigella boydii and Salmonella typhimurium. This study demonstrated the biofabrication of AgNPs by using C. carandas leaves extract and a potential in vitro biological application as antioxidant, anticancer and antibacterial agents.Inspec keywords: antibacterial activity, biomedical materials, cancer, tumours, nanomedicine, silver, nanoparticles, reduction (chemical), nanofabrication, ultraviolet spectra, visible spectra, field emission scanning electron microscopy, Fourier transform infrared spectra, X‐ray chemical analysis, X‐ray diffraction, thermal stability, thermal analysis, free radical reactions, toxicology, cellular biophysics, microorganismsOther keywords: total phenolic contents, free radical scavenging activities, 2,2‐diphenyl‐1‐picrylhydrazyl test, ferric reducing antioxidant power assay, in vitro cytotoxicity, hepatic cell lines HUH‐7, renal cell lines HEK‐293, antibacterial activity, methicillin‐resistant Staphylococcus aureus, Shigella sonnei, Shigella boydii, Salmonella typhimurium, biofabrication, in vitro biological application, Ag, total flavonoid contents, thermogravimetric analysis, thermal stability, face‐centred cubic structure, X‐ray diffraction, energy dispersive X‐ray spectroscopy, distinctive peak, spherical shape, field emission scanning electron microscope, Fourier transforms infrared spectroscopy, stabilising agent, reducing agent, bioactive molecules, absorption maxima, UV‐visible spectroscopy, plant extract colour, antibacterial activities, anticancer activities, antioxidant activities, Carissa carandas, aqueous leaves extract, silver nanoparticles, structural characterisation, one‐pot green synthesis 相似文献
999.
Souradip Ganguly;Pooja Basera;Sahnawaz Ahmed;Sukanta Saha;Arnab Dutta;Chanchal Loha;Sirshendu Ghosh; 《Small (Weinheim an der Bergstrasse, Germany)》2024,20(52):2405056
Electro-valorization of biomass-derived chemicals has ensured sustainable production of value-added products, an effective approach for reducing carbon footprint, through renewable energy. Electrochemical oxidation and reduction reactions in aqueous media using H2O as a potential source for active hydrogenated and oxygenated species fulfill the purpose. In this study, Ru─Co2P nanorods are explored as a bifunctional electrocatalyst toward valorization of Organics at basic media. The in-situ electrogenerated Co3+ and Co4+ species act as active oxidants toward product selectivity. An overpotential of 68 mV is found for hydrogen evolution reaction (1 m NaOH) with Ru─Co2P. Further, used as cathode, Ru─Co2P effectively reduces furfuraldehyde to furfuryl alcohol and p-nitrophenol to p-aminophenol. Ru doping enables ease of formation of active species both for reduction and oxidation, faster charge transfer between catalyst to absorbates. Density Functional Theory calculation establishes Ru incorporation in Co2P surface results in enhanced adsorption of substrates. Ru doping modulates the electronic structure of Co2P which changes the density of states resulting in faster water dissociation and water splitting. To reach 10 mA cm−2 current density only 1.6 V is required for water electrolysis, whereas 1.4 V is enough for substrate-paired electrolysis with simultaneous oxidation of benzyl alcohol and reduction of p-nitro phenol. 相似文献
1000.
Harish Verma;Arpita Tripathi;Shail Upadhyay; 《International Journal of Applied Ceramic Technology》2024,21(4):3032-3047
In this work, perovskite oxide SrCeO3 was synthesized using the solution combustion method (SCM). Synthesized samples have been characterized using X-ray diffraction (XRD), Raman, ultra violet (UV)–visible spectroscopy, and scanning electron microscopy (SEM) techniques. The XRD and Rietveld refinement has confirmed the orthorhombic structure with space group Pnma. The average grain size of this ceramic sample is 1.2 µm. The dielectric constant, dissipation factor, modulus, impedance, and alternating current (AC) and direct current (DC) conductivities were analyzed in the temperature range RT to 600°C and frequency range 20 Hz–2 MHz. Further, it was observed that the role of grain boundaries in dielectric and electrical properties is significant, at low temperatures. The origin of the dielectric relaxation and conduction process is the same. The activation energy for DC conduction (Edc) was found to be .79 eV. Electrical conduction/relaxation is assigned to the diffusion of doubly ionized oxygen (Vo··). The value of DC conductivity (1.2 × 10−3 Ω−1 cm−1 at 600°C) and activation energy of .79 eV is very close to the values reported for doped CeO2-based oxide ion conductors for SOFCs. This study has demonstrated that SrCeO3 can be an alternative candidate for the oxide ion conductor electrolyte application and the potential to be used as a thermally stable capacitor application for microwave dielectric applications. 相似文献