Combined impact of UV radiation and nitric acid on HDPE containers during outdoor exposure

2018 ◽  
Vol 60 (3) ◽  
pp. 257-264
Author(s):  
Anja Geburtig ◽  
Volker Wachtendorf ◽  
Anita Schmidt ◽  
Thomas Goedecke
Keyword(s):  
Nitric Acid ◽  
Uv Radiation ◽  
Outdoor Exposure ◽  
Combined Impact

scholarly journals Evaluation of the Impacts of Four Weathering Methods on Two Acrylic Paints: Showcasing Distinctions and Particularities

Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 121 ◽  
Author(s):  
Antoine Cogulet ◽  
Pierre Blanchet ◽  
Véronic Landry
Keyword(s):  
Uv Radiation ◽  
Outdoor Exposure ◽  
Accelerated Weathering ◽  
Accurate Assessment ◽  
End Use ◽  
Weathering Resistance ◽  
Weathering Process ◽  
Acrylic Paints

Two commercial waterborne wood acrylic paints were applied to wood samples and the weathering resistance of samples was tested using four different weathering methods: outdoor exposure in Arizona (USA), Florida (USA), and the province of Quebec (Canada), and accelerated weathering in a QUV (fluorescent) weatherometer. Degradation was characterised by colorimetric and FTIR analyses. FTIR confirmed the importance of paint composition in the resistance of samples to weathering. Polymer sensitivity to UV radiation was clearly evident. An interpretation of discoloration in terms of either the energy received by the samples or the length of exposure is presented. Strong differences existed between the four weathering methods. Particularities of each method are discussed and recommendations regarding their application for effective testing are proposed. Overall, in addition to accelerated weathering tests, we conclude that it is necessary to test paints in an end-use environment for accurate assessment of their likely performance. This study confirms the multifactorial aspect of the weathering process.

The Effect of Ageing on Rheological Properties and Chemical Conversions of Asphalts

2008 ◽  
Vol 385-387 ◽  
pp. 481-484
Author(s):  
Shao Peng Wu ◽  
Ling Pang ◽  
Guo Jun Zhu
Keyword(s):  
Rheological Properties ◽  
Uv Radiation ◽  
Polymer Networks ◽  
Weight Percent ◽  
Outdoor Exposure ◽  
Laboratory Simulation ◽  
Dynamic Shear ◽  
Styrene Butadiene ◽  
Sbs Modified Asphalt ◽  
The Relationship

Asphalt ageing induced by heat, oxidation and ultraviolet (UV) radiation was investigated using various laboratory simulation ageing methods and outdoor ageing. One normal 70 penetration asphalt and its styrene-butadiene-styrene (SBS) modified asphalt were employed to assess the changes in chemical and rheological properties by infrared spectroscopy and dynamic shear rheometer under various ageing conditions, thus the relationship among rolling thin-film oven(RTFO), pressurized ageing vessel (PAV) and UV radiation ageing was distinguished. Experimental results showed that photodegradation caused by outdoor exposure UV ageing of 50~200µm thin films for a month, was found to be the most severe, following by PAV and then RTFO with respects to rehological and chemical changes. Photodegradation effect decreased as the thickness of asphalt film increases. Dynamic shear tests indicated that polymer networks were gradually destroyed during ageing, but the aged SBS modified asphalts still displayed better rheological properties than the corresponding base asphalt. The weight percent of oxygen as carbonyl increased and of SBS as butadiene decreased after ageing based on infrared spectrums. However, chemical and rheological changes were not generally consistent, and ageing susceptibility may be ranked differently when different evaluation methods were used.

Ectodesmata as Revealed By Freeze-Etch Preparations of Plant Epidermal Cell Walls

1973 ◽  
Vol 31 ◽  
pp. 468-469
Author(s):  
N.C. Lyon ◽  
W. C. Mueller
Keyword(s):  
Electron Microscopy ◽  
Acetic Acid ◽  
Nitric Acid ◽  
Oxalic Acid ◽  
Light Microscopy ◽  
Epidermal Cell ◽  
Cell Walls ◽  
Plant Viruses ◽  
Plant Leaves ◽  
Thin Sections

Schumacher and Halbsguth first demonstrated ectodesmata as pores or channels in the epidermal cell walls in haustoria of Cuscuta odorata L. by light microscopy in tissues fixed in a sublimate fixative (30% ethyl alcohol, 30 ml:glacial acetic acid, 10 ml: 65% nitric acid, 1 ml: 40% formaldehyde, 5 ml: oxalic acid, 2 g: mecuric chloride to saturation 2-3 g). Other workers have published electron micrographs of structures transversing the outer epidermal cell in thin sections of plant leaves that have been interpreted as ectodesmata. Such structures are evident following treatment with Hg++ or Ag+ salts and are only rarely observed by electron microscopy. If ectodesmata exist without such treatment, and are not artefacts, they would afford natural pathways of entry for applied foliar solutions and plant viruses.

Neutrophil Myeloperoxidase Destruction by Ultraviolet Irradiation

1988 ◽  
Vol 46 ◽  
pp. 138-139
Author(s):  
J. Hanker ◽  
B. Giammara ◽  
G. Strauss
Keyword(s):  
Uv Radiation ◽  
Myeloid Leukemia ◽  
Stratospheric Ozone ◽  
Psoriasis Patient ◽  
Whole Body ◽  
Human Neutrophils ◽  
Cupric Nitrate ◽  
The Earth ◽  
Routine Handling ◽  
Uvb Phototherapy

Only a fraction of the UV radiation emitted by the sun reaches the earth; most of the UVB (290-320nm) is eliminated by stratospheric ozone. There is increasing concern, however, that man-made chemicals are damaging this ozone layer. Although the effects of UV on DNA or as a carcinogen are widely known, preleukemia and acute myeloid leukemia (AML) have only rarely been reported in psoriasis patients treated with 8-methoxypsoralen and UV (PUVA). It was therefore of interest to study the effects of UV on the myeloperoxidase (MP) activity of human neutrophils. The peroxidase activity of enriched leukocyte preparations on coverslips was shown cytochemically with a diaminobenzidine medium and cupric nitrate intensification.Control samples (Figs. 1,4,5) of human bloods that were not specifically exposed to UV radiation or light except during routine handling were compared with samples which had been exposed in one of several different ways. One preparation (Fig. 2) was from a psoriasis patient who had received whole-body UVB phototherapy repeatedly.

The Action of Nitric Acid on Aluminium

1916 ◽  
Vol 82 (2122supp) ◽  
pp. 150-150
Author(s):  
R. Seligman ◽  
P. Williams
Keyword(s):  
Nitric Acid

ecovery of Tin and Nitric Acid from Spent Solder Stripping Solutions

2015 ◽  
Vol 53 (6) ◽  
pp. 426-431 ◽  
Author(s):  
Jae-Woo Ahn ◽  
Seong-Hyung Ryu ◽  
Tae-Young Kim
Keyword(s):  
Nitric Acid
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