Sono state eseguite alcune reazioni di modificazione su poIibutadieni liquidi, aventi struttura 1,4 oppure prevalente 1,2, per addizione, indotta da radiazioni UV, di composti tiolici con!enenti gruppi funzionali quali l'acido 3-tiopropionico o il mercapto-propil-trietossi-silano oppure di CBr4 sui doppi Iegami del polibutadiene. I prodotti contene...
Published in Canadian family physician Médecin de famille canadien
The absorption of ultraviolet (UV) light by stratospheric ozone is crucial to the provision of an environment suitable for terrestrial life. Ultraviolet radiation is the part of the solar spectrum with wavelengths between 240 and 400 nm. Photons at wavelengths below about 320 nm can produce photochemical damage to the cells of living organisms. Dat...
The present investigation shows a possibility to reach an excellent sterilization rate of high resistant microorganisms on food packaging materials in a split second using UV-C-irradiation. This was enabled by means of the large power-density of the high-power-UV-C-lamp UVATEC-series (Dr. K. Hönle GmbH, Planegg), used. The inactivation of Aspergill...
Physical stress to seaweeds and hunger stress of herbivores can influence the outcome of chemically mediated seaweed—herbivore interactions. The unpalatable brown seaweed Dictyota ciliolata produces the diterpenoid secondary metabolites pachydictyol A, dictyol B acetate, and dictyodial. At natural concentrations, pachydictyol A deterred the sea urc...
Medições da coluna total de ozônio e da radiação UV-B (280 - 320 nm) estão sendo realizadas desde julho de 1992 em Punta Arenas, Chile, num esforço conjunto entre a Universidade de Magallanes - UMAG, Chile e o Instituto Nacional de Pesquisas Espaciais - INPE, Brasil. Punta Arenas é uma cidade de aproximadamente 100.000 habitantes, que se encontra e...
An experimental program was devised by the authors to firstly, provide students with practical ‘hands-on’ experience of concepts of physics, and secondly, increase awareness of the dangers of UV radiation by a series of scientific measurements on UV irradiance levels. A group of grade 10 students undertook the experiment and sample results are pres...
Experiments on wakeful rats revealed that the second phase of hyperthermal response evoked by intraperitoneal administration of endotoxin is eliminated after intravascular irradiation of venous blood in the ultraviolet range during the first phase of experimental fever.
Published in Journal of Atmospheric Chemistry
A calibrated spectroradiometer was used for the measurement of spectra of the absolute actinic flux Fλ during the POPCORN field campaign in Pennewitt (53.8° N, 11.7° E, sea level) in August 1994. The obtained set of actinic flux spectra was used to determine the photolysis frequencies J(O1D), J(NO2), J(HCHO), J(H2O2), J(HONO), and J(CH3CHO), using ...
Published in Aquatic Ecology
We used a device called a Phototron to measure the effects of UV radiation on the cosmopolitan algae, Cryptomonas erosa, grown in continuous cultures. In the Phototron, we investigated changes in photosynthetic parameters (Pmax – specific production rate at optimal light intensity; α – initial slope of the linear portion of the Photosynthesis-Irrad...
