1,721,123 research outputs found
Protective textiles from the past and for the modern age
No full textOur skin is a delicate environment. Temperature, humidity, UV rays, and other factors might induce unwanted alterations leading first to discomfort and later to skin alteration. For this reason, men always spent time and effort creating new technologies for textiles. Nowadays, protective textiles are well integrated having access to many materials and technologies, including a possible future where textiles are smart and, thanks to their sensors and actuators, can have an active protection. Nevertheless, modernity means use of high amount of natural resources and, in the context of sustainability, we might need to check back to our past and consider again old fibers, like Spanish Broom or Nettle
Chimica. Principi e applicazioni
No full textScritto e pensato in funzione delle esigenze degli studenti, siano essi universitari o più giovani, il manuale "Chimica. Princìpi e applicazioni" nasce dalle esperienze didattiche degli autori e, allo stesso tempo, dalle esperienze di applicazione sul campo dei princìpi della chimica. Dalla teoria alla prassi, dalle più piccole componenti atomiche della materia sino alle grandi centrali per la produzione dell'energia, il volume ci accompagna alla scoperta del complesso mondo che ci circonda, un mondo che viene scomposto e letto attraverso gli elementi della chimica
Selective extraction of liquid fuel from urban wastewater sludge by microwave-controlled pyrolysis
No full textMICROWAVE-ASSISTED PYROLYSIS AS A TECHNOLOGY FOR “BIODIESEL” PRODUCTION FROM WASTEWATER TREATMENT SLUDGE
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Tetrabutylammonium decatungstate-photosensitized alkylation of electrophilic alkenes: conveniente functionalization of aliphatic C-H bonds
No full textInteractions between different solar UVB/UVA filters container in commercial suncream and consequent loss of UV protection
No full textEPR Investigation of sulphur radicals in the mechanism of accelerated sulphur vulcanization of SBR elastomers.
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Inorganic and organic UV filters. Their role and efficacy in suncreens and suncare products
No full textMinerals such as titanium dioxide, TiO2, and zinc oxide, ZnO, are well known active semiconductor photocatalysts used extensively in heterogeneous photocatalysis to destroy environmental pollutants that are organic in nature. They are also extensively used in sunscreen lotions as active broadband sunscreens that screen both UVB (290–320 nm) and UVA (320–400 nm) sunlight radiation and as high SPF makers. When so photoactivated by UV light, however, these two particular metal oxides are known to generate highly oxidizing radicals (OH and O2) and other reactive oxygen species (ROS) such as H2O2 and singlet oxygen, 1O2, which are known to be cytotoxic and/or genotoxic. Hydroxyl (OH) radicals photogenerated from photoactive TiO2 specimens extracted from commercial sunscreen lotions induce damage to DNA plasmids in vitro and to whole human skin cells in cultures. Accordingly, the titanium dioxide particle surface was modified to produce TiO2 specimens of considerably reduced photoactivity. Deactivation of TiO2 diminishes considerably, in some cases completely suppresses damage caused to DNA plasmids, to human cells, and to yeast cells compared to non-modified specimens exposed to UVB/UVA simulated solar radiation. The photostabilities of sunscreen organic active agents in neat polar and apolar solvents and in actual commercial formulations have been examined. With rare exceptions, the active ingredients undergo photochemical changes (in some cases form free radicals)
and the sunscreen lotions lose considerable Sun protection efficacy only after a relatively short time when exposed to simulated
sunlight UVB/UVA radiation, confirming the recent findings by Sayre et al. [R.M. Sayre, J.C. Dowdy, A.J. Gerwig, W.J. Shields,
R.V. Lloyd, Photochem. Photobiol. 81 (2005) 452]
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