Search results for " Paper"
showing 10 items of 1695 documents
Biomass Waste Processing into Artificial Humic Substances
2021
Abstract To address the biomass waste processing problem and transform it into refractory forms of carbon, recently suggested hydrothermal carbonization (HTC) of biomass in alkaline environment can be considered as a prospective and climate neutral approach. Biomass HTC provides possibilities to obtain form of biochar (hydrochar) and artificial humic substances, however the conditions of the HTC have not been much studied. Optimization by Response Surface Methodology of the HTC using microwave treatment with three experimental variables (treatment temperature, length of microwave treatment, amount of biomass per volume) provides the possibility to significantly increase the yield of humic s…
Co-reductive fabrication of carbon nanodots with high quantum yield for bioimaging of bacteria
2018
A simple and straightforward synthetic approach for carbon nanodots (C-dots) is proposed. The strategy is based on a one-step hydrothermal chemical reduction with thiourea and urea, leading to high quantum yield C-dots. The obtained C-dots are well-dispersed with a uniform size and a graphite-like structure. A synergistic reduction mechanism was investigated using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The findings show that using both thiourea and urea during the one-pot synthesis enhances the luminescence of the generated C-dots. Moreover, the prepared C-dots have a high distribution of functional groups on their surface. In this work, C-dots proved …
Relationship between authors’ keywords in journal papers and indexing terms in databases ISOC, IME and ICYT
2005
The keywords provided by authors in their scientific articles and the descriptors assigned to those articles in various databases are analysed to find out the role played by these keywords during the indexing process. In order to do that, 108 periodical publications proportionally distributed between Social Sciences and Humanities (36 journals), Science and Technology (36) and Medical and Health Sciences (36) were selected. Ten articles were selected from each of the 108 journals from different years, so that we worked altogether on 1080 articles meeting two conditions: including keywords and being indexed in the databases ISOC, ICYT or IME. Then, we proceeded to draw a comparison between t…
The Nanoeconomics of Firm‐Level Decision‐Making and Industry Evolution : Evidence from 200 Years of Paper and Pulp Making
2020
Research summary We explore the qualitative differences in entries and exits over time. Using qualitative and quantitative data on 96 firms over 200 years, we study industry evolution from the perspective of individual decision‐making situations. Our historical and statistical analyses reveal the vital role of technology investments in determining firm outcomes, and the technological, institutional and governance dynamics that lead firms to invest or to abstain. Our main theoretical and methodological contribution concerns the importance of the multiplicity of firm‐level rationalities and decisions as fundamentals in theorizing on industry evolution. Managerial summary What determines firm …
Halogen bonding and host-guest chemistry between
2019
Single crystal X-ray structures of halogen-bonded assemblies formed between host N-hexylammonium resorcinarene bromide (1) or N-cyclohexylammonium resorcinarene chloride (2), and 1,4-diiodooctafluorobutane and accompanying small solvent guests (methanol, acetonitrile and water) are presented. The guests’ inclusion affects the geometry of the cavity of the receptors 1 and 2, while the divalent halogen bond donor 1,4-diiodooctafluorobutane determines the overall nature of the halogen bond assembly. The crystal lattice of 1 contains two structurally different dimeric assemblies A and B, formally resulting in the mixture of a capsular dimer and a dimeric pseudo-capsule. 1H and 19F NMR analyses …
(Z)-1-Chloro-1-[2-(2-nitrophenyl)hydrazinylidene]propan-2-one
2012
The title molecule, C9H8ClN3O3, lies on a mirror plane. Intramolecular N—H...O and N—H...Cl hydrogen bonds occur. One of the nitro O atoms is disordered (site occupancy ratio = 0.40:0.10).
The enrichment ratio of atomic contacts in crystals, an indicator derived from the Hirshfeld surface analysis
2014
An enrichment ratio is derived from the decomposition of the crystal contact surface between pairs of interacting chemical species. The propensity of different contact types to form is investigated.
Synergistic Anticancer Therapy by Ovalbumin Encapsulation-Enabled Tandem Reactive Oxygen Species Generation
2020
Abstract The anticancer efficacy of photodynamic therapy (PDT) is limited due to the hypoxic features of solid tumors. We report synergistic PDT/chemotherapy with integrated tandem Fenton reactions mediated by ovalbumin encapsulation for improved in vivo anticancer therapy via an enhanced reactive oxygen species (ROS) generation mechanism. O2 .− produced by the PDT is converted to H2O2 by superoxide dismutase, followed by the transformation of H2O2 to the highly toxic .OH via Fenton reactions by Fe2+ originating from the dissolution of co‐loaded Fe3O4 nanoparticles. The PDT process further facilitates the endosomal/lysosomal escape of the active agents and enhances their intracellular deliv…
Effective Recovery Process of Copper from Waste Printed Circuit Boards Utilizing Recycling of Leachate
2020
AbstractThis study presents an optimized leaching and electrowinning process for the recovery of copper from waste printed circuit boards including studies of chemical consumption and recirculation of leachate. Optimization of leaching was performed using response surface methodology in diluted sulfuric acid and hydrogen peroxide media. Optimum leaching conditions for copper were found by using 3.6 mol L−1 sulfuric acid, 6 vol.% hydrogen peroxide, pulp density of 75 g L−1 with 186 min leaching time at 20°C resulting in complete leaching of copper followed by over 92% recovery and purity of 99.9% in the electrowinning. Study of chemical consumption showed total decomposition of hydrogen pero…
Novel supramolecular affinity materials based on (−)-isosteviol as molecular templates
2013
The readily available ex-chiral-pool building block (−)-isosteviol was combined with the C3-symmetric platforms hexahydroxytriphenylene and hexaaminotriptycene providing large and rigid molecular architectures. Because of the persistent cavities these scaffolds are very potent supramolecular affinity materials for head space analysis by quartz crystal microbalances. The scaffolds serve in particular as templates for tracing air-borne arenes at low concentration. The affinities of the synthesized materials towards different air-borne arenes were determined by 200 MHz quartz crystal microbalances.