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- Baruah, Sunandan, et al.
(författare)
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Perspectives and applications of nanotechnology in water treatment
- 2016
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Ingår i: Environmental Chemistry Letters. - : Springer. - 1610-3653 .- 1610-3661. ; 14:1, s. 1-14
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Forskningsöversikt (refereegranskat)abstract
- Industrialization and excessive use of pesticides for boosting agricultural production have adversely affected the ecosystem, polluting natural water reserves. Remediation of contaminated water has been an area of concern with numerous techniques being applied to improve the quality of naturally available water to the level suitable for human consumption. Most of these methods, however, generate by-products that are sometimes toxic. Heterogenous photocatalysis using metal oxide nanostructures for water purification is an attractive option because no harmful by-products are created. A discussion on possible methods to engineer metal oxides for visible light photocatalysis is included to highlight the use of solar energy for water purification. Multifunctional photocatalytic membranes are considered advantageous over freely suspended nanoparticles due to the ease of its removal from the purified water. An overview of water remediation techniques is presented, highlighting innovations through nanotechnology for possible addressing of problems associated with current techniques.
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| 2. |
- Baruah, S., et al.
(författare)
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pH-dependent growth of zinc oxide nanorods
- 2009
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Ingår i: Journal of Crystal Growth. - : Elsevier. - 0022-0248 .- 1873-5002. ; 311:8, s. 2549-2554
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Tidskriftsartikel (refereegranskat)abstract
- Here we study the effect of pH variation on the dimension and morphology of zinc oxide (ZnO) nanorods grown through hydrothermal process at temperatures less than 100 °C. ZnO nanorods were grown on pre-seeded glass substrates using zinc nitrate hexahydrate as the source of Zn ions and hexamethylenetetramine as the source of hydroxyl ions. The pH of the reaction bath was found to change gradually from 6.4 to 7.3 in 5 h during the growth process. The growth of the ZnO nanorods was observed to be faster, both laterally and longitudinally, when the growth solution was in basic conditions. However, flower petal like ZnO nanostructures were obtained when the growth process was initiated in basic condition (pH 8–12), indicating that initial acidic conditions were required to obtain nanorods with well-defined hexagonal facets. ZnO is known to erode in acidic condition and the final dimension of the nanorods is determined by a competition between crystal growth and etching. ZnO nanorods of different dimensions, both laterally (diameters ranging from 220 nm to 1 μm) and longitudinally (lengths ranging from 1 to 5.6 μm) were successfully synthesized using the same concentration of zinc nitrate and hexamine in the reaction bath and the same growth duration of 5 h simply through appropriate control of the pH of the reactant solution between 6 and 7.3.
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| 5. |
- Fredholm, Kent
(författare)
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När språket flyttar ut på nätet : Exempel på gräsrotsinsatser för att revitalisera ladino
- 2023
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Ladino eller sefardisk spanska är ett judiskt minoritetsspråk baserat på senmedeltida spanska uppblandad med andra romanska språk, turkiska, grekiska och hebreiska. Antalet modersmålstalare beräknas ligga mellan tio och femtio tusen. De flesta är över 60 och språket har i mycket liten utsträckning överförts till yngre generationer. Talarna lever utspridda i östra Medelhavsområdet, Nord- och Sydamerika och andra delar av världen, vilket försvårar kontakten mellan dem som ännu kan språket. Dess möjligheter att överleva beskrivs av alla dessa anledningar som små. Under covid-pandemin inleddes dock en stor mängd insatser online för att revitalisera språket och för att ge dess talare nya möjligheter att mötas. I föredraget ges exempel på sådana insatser. Med utgångspunkt i en nyligen avslutad intervjustudie med lärare i ladino diskuteras också behov för fortsatt språkrevitalisering.
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