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31.
Ojah Namita Thakur Susmita Gogoi Dolly Ahmed Gazi Ameen Mandal Manabendra Doley Robin Choudhury Arup Jyoti 《Plasma Chemistry and Plasma Processing》2022,42(1):147-162
Plasma Chemistry and Plasma Processing - This work reports an investigation of the discharge characteristics of atmospheric dielectric barrier discharge (DBD) plasma in terms of I-V curves and... 相似文献
32.
Sabine Briede Anda Barkane Maksims Jurinovs Vijay Kumar Thakur Sergejs Gaidukovs 《Current Opinion in Green and Sustainable Chemistry》2022
Over the years, eco-friendly raw biomass is being investigated to develop novel green monomer and oligomer components for sustainable polymer materials synthesis. The use of naturally obtained biomass can reduce the dependence on petrochemical suppliers and the impact of petroleum prices. Polymer materials obtained from biomass are a competitive alternative comparing with those made from petrochemicals. Domestically and industrially used vegetable oil derivatives are considered widely available, while cellulose derivatives are the most abundant natural polymers. Biobased acrylic polymers developed from vegetable oils and cellulose are very popular nowadays. Using acrylic derivatives of vegetable oils and cellulose as naturally obtained materials leads to long-lasting biopolymers with a wide range of high exploitation properties and applications. The characteristics of vegetable oil- and cellulose-based acrylate resins of high-biorenewable carbon content are suitable for industrial application, while their role is still underestimated. A brief analysis of biomass-derived biopolymer resin compositions, properties, and applications is critically outlined herein. 相似文献
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34.
Amar Singh Singha Bhanu Priya Thakur 《International Journal of Polymer Analysis and Characterization》2014,19(2):115-123
Grafting of methyl methacrylate (MMA) onto delignified Grewia optiva fiber using ascorbic acid/H2O2 as an initiator was carried out under microwave irradiation. The effects of varying the microwave power, exposure time, and concentration of initiator and monomer of graft polymerization were studied to obtain maximum grafting percentage (26.54%). The experimental results showed that the optimal conditions for grafting were: exposure time, 10min; microwave power, 110 W; ascorbic acid concentration, 3.74mol/L × 10?2; H2O2 concentration, 0.97mol/L × 10?1; monomer concentration, 1.87mol/L × 10?1. The graft copolymers were characterized by Fourier transform-infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). 相似文献
35.
Prof. Daniel W. Armstrong Dr. Mohsen Talebi Nimisha Thakur Dr. M. Farooq Wahab Dr. Alexander V. Mikhonin Matt T. Muckle Dr. Justin L. Neill 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(1):198-202
We designed and demonstrated the unique abilities of the first gas chromatography–molecular rotational resonance spectrometer (GC-MRR). While broadly and routinely applicable, its capabilities can exceed those of high-resolution MS and NMR spectroscopy in terms of selectivity, resolution, and compound identification. A series of 24 isotopologues and isotopomers of five organic compounds are separated, identified, and quantified in a single run. Natural isotopic abundances of mixtures of compounds containing chlorine, bromine, and sulfur heteroatoms are easily determined. MRR detection provides the added high specificity for these selective gas-phase separations. GC-MRR is shown to be ideal for compound-specific isotope analysis (CSIA). Different bacterial cultures and groundwater were shown to have contrasting isotopic selectivities for common organic compounds. The ease of such GC-MRR measurements may initiate a new era in biosynthetic/degradation and geochemical isotopic compound studies. 相似文献
36.
N. Neibolts O. Platnieks S. Gaidukovs A. Barkane V.K. Thakur I. Filipova G. Mihai Z. Zelca K. Yamaguchi M. Enachescu 《Materials Today Chemistry》2020
Sustainable materials have slowly overtaken the nanofiber research field while the tailoring of their properties and the upscaling for industrial production are some of the major challenges. We report preparation of nanofibers that are bio-based and biodegradable prepared from poly (butylene succinate) (PBS) with the incorporation of nanofibrillated cellulose (NFC) and graphene nanoplatelets (GN). NFC and GN were combined as hybrid filler, which led to the improved morphological structure for electrospun nanofibers. A needleless approach was used for solution electrospinning fabrication of nanofiber mesh structures to promote application scalability. The polymer crystallization process was examined by differential scanning calorimetry (DSC), the thermal stability was evaluated by thermal gravimetric analysis (TGA), while the extensive investigation of the nanofibers structure was carried out with scanning electron microscopy (SEM) and atomic force microscopy (AFM). NFC and GN loadings were 0.5 and 1.0 wt %; while poly (ethylene glycol) (PEG) was employed as a compatibilizer to enhance fillers’ interaction within the polymer matrix. The interactions in the interface of the fillers and matrix components were studied by FTIR and Raman spectroscopies. The hybrid filler approach proved to be most suitable for consistent and high-quality nanofiber production. The obtained dense mesh-based structures could have foreseeable potential application in biomedical field like scaffolds for the tissue and bone recovery, while other applications could focus on filtration technologies and smart sensors. 相似文献
37.
Saurav Goel Sara Hawi Gaurav Goel Vijay Kumar Thakur Anupam Agrawal Clare Hoskins Oliver Pearce Tanvir Hussain Hari M. Upadhyaya Graham Cross Asa H. Barber 《Materials Today Chemistry》2020
The world is witnessing tumultuous times as major economic powers including the US, UK, Russia, India, and most of Europe continue to be in a state of lockdown. The worst-hit sectors due to this lockdown are sales, production (manufacturing), transport (aerospace and automotive) and tourism. Lockdowns became necessary as a preventive measure to avoid the spread of the contagious and infectious “Coronavirus Disease 2019” (COVID-19). This newly identified disease is caused by a new strain of the virus being referred to as Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS CoV-2; formerly called 2019-nCoV). We review the current medical and manufacturing response to COVID-19, including advances in instrumentation, sensing, use of lasers, fumigation chambers and development of novel tools such as lab-on-the-chip using combinatorial additive and subtractive manufacturing techniques and use of molecular modelling and molecular docking in drug and vaccine discovery. We also offer perspectives on future considerations on climate change, outsourced versus indigenous manufacturing, automation, and antimicrobial resistance. Overall, this paper attempts to identify key areas where manufacturing can be employed to address societal challenges such as COVID-19. 相似文献
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39.
Reznikov et al. [Phys. Rev. Lett. 75, 3340 (1995)]] have presented definitive observations of nonequilibrium noise in a quantum point contact. Especially puzzling is the "anomalous" peak structure of the excess noise measured at constant current; to date it remains unexplained. We show that their experiment directly reveals the deep link between conservation principles in the electron gas and its low-dimensional, mesoscopic behavior. The keys to that connection are gauge invariance and the compressibility sum rule. These are central not only to the experiment of Reznikov et al., but to the very nature of all mesoscopic transport. 相似文献
40.
Eight new macrocyclic ligands have been prepared by the reaction of the precursor diketone (benzil, glyoxal, diacetyl or 2,3-pentanedione) with a diamine (thiosemicarbazide or semicarbazide). Copper(II) complexes of these ligands have been synthesized and characterized by elemental analysis, molar conductance, magnetic susceptibility, i.r., u.v.–vis, 1H-n.m.r., mass and e.p.r. spectral studies. Mass, n.m.r. and i.r. data indicate the condensation of the diamine and diketone and the whole molecular ion structure. g-Values are calculated for all of the complexes in polycrystalline form as well as in DMSO solution. Spin Hamiltonian values and bonding parameters have also been calculated which indicates that an unpaired electron is present in the
orbital. The metal-ligand bonding parameters shows strong in-plane σ sigma and in-plane π bonding. The magnetic and spectral data indicate tetragonal geometry for all of the complexes except [CuH2L4]Cl2 and [CuH2L4]Cl2 which are square planar. From c.v. data reversible CuII/CuI couples are observed for these complexes. The macrocyclic complexes show more antibacterial and antiviral activity as compared to the ligands. The antibacterial activities of the compounds were tested against S. aureus, S. subtillis and E. coli. 相似文献