Evaluation by IR spectroscopy of the degradation of different types of commercial polyethylene exposed to UV radiation and domestic compost in ambient conditions

2020 ◽  
Vol 138 (14) ◽  
pp. 50158
Author(s):  
Karla I. Martínez ◽  
Rosario González‐Mota ◽  
Juan José Soto‐Bernal ◽  
Iliana Rosales‐Candelas
Keyword(s):  
Ir Spectroscopy ◽  
Uv Radiation ◽  
Ambient Conditions ◽  
Different Types

Rapid authentication and identification of different types of A. roxburghii by Tri-step FT-IR spectroscopy

2018 ◽  
Vol 199 ◽  
pp. 271-282 ◽  
Author(s):  
Ying Chen ◽  
Jinfang Huang ◽  
Zhao Qin Yeap ◽  
Xue Zhang ◽  
Shuisheng Wu ◽  
...  
Keyword(s):  
Ir Spectroscopy ◽  
Different Types ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

The structure and properties of different types of starch exposed to UV radiation: A comparative study

2013 ◽  
Vol 98 (1) ◽  
pp. 477-482 ◽  
Author(s):  
Dagmara Bajer ◽  
Halina Kaczmarek ◽  
Krzysztof Bajer
Keyword(s):  
Comparative Study ◽  
Uv Radiation ◽  
Structure And Properties ◽  
Different Types

scholarly journals Can natural products improve skin photoprotection?

Rodriguésia ◽  
2020 ◽  
Vol 71 ◽  
Author(s):  
Bruna Galdorfini Chiari-Andréo ◽  
Fernanda Borges de Almeida ◽  
Paulo Renato Yamasaki ◽  
Jean Leandro dos Santos ◽  
Marcos Antonio Corrêa ◽  
...  
Keyword(s):  
Natural Products ◽  
Uv Radiation ◽  
Stratospheric Ozone ◽  
Uv Filters ◽  
Skin Damage ◽  
Protective Mechanisms ◽  
Different Types ◽  
Phytochemical Compounds

Abstract Due to increased UV radiation on the Earth’s surface, caused by depletion of the stratospheric ozone, people have become more susceptible to different types of skin damage, such as erythema, sunburns, and cancer; this is especially of concern in tropical countries. Thus, efforts to improve awareness as well as the use of sunscreen are increasing worldwide. However, synthetic UV filters have been associated with deleterious effects such as photosensitization. Natural products have been used by ancient cultures for several purposes, including protecting the skin from the sun. However, there is still doubt today whether photoprotection is a real phenomenom or whether it is simply tanning of the skin. Plants have self-protective mechanisms and produce secondary metabolites that can protect themselves from UV radiation. Yet, can phytochemical compounds protect human skin? This review discusses the paradoxical effect of chemical UV filters and the influence of phytochemicals in in vitro and in vivo tests of photoprotection.

scholarly journals Tracking the light-induced isomerization processes and the photostability of spiropyrans embedded in the pores of crystalline nanoporous MOFs via IR spectroscopy

2020 ◽  
Vol 19 (10) ◽  
pp. 1433-1441
Author(s):  
Heidi A. Schwartz ◽  
Dominik Schaniel ◽  
Uwe Ruschewitz
Keyword(s):  
Ir Spectroscopy ◽  
Merocyanine Form ◽  
Ambient Conditions ◽  
Isomerization Processes

Difference IR spectroscopy of spiropyran@MOF systems to obtain the characteristic signatures of the spiropyran and merocyanine form at ambient conditions.

scholarly journals On Long-Term Stability of Metallic Glasses

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1076 ◽  
Author(s):  
Louzguine-Luzgin ◽  
Jiang
Keyword(s):  
Metallic Glasses ◽  
Surface Oxidation ◽  
Initial Structure ◽  
Ambient Conditions ◽  
Scanning Calorimetry ◽  
Long Term Stability ◽  
Transmission Electron ◽  
Different Types ◽  
Thermal Stability Of

Thermal stability of different types of metallic glasses and partially crystalline alloys stored for at least 15 years at ambient conditions was tested in the present work by differential scanning calorimetry in comparison with that of the original alloys tested in the as-cast state in the earlier works. The structure of the naturally aged alloys was also studied by X-ray diffractometry. The structure of a couple of selected alloys was also tested by transmission electron microscopy. Most of the alloys retained their initial structure and showed only a moderate decrease in the crystallization temperature. Only those alloys which showed visible surface oxidation (Cu-Zr-system based) were partly transformed into a crystalline state forming micron-scale Cu particles in air at ambient conditions.

Shear-Induced Microporous Nanocomposite Epoxy Thermosets (MiNET)

2020 ◽  
Author(s):  
Molla Hasan ◽  
Yogin Patel ◽  
Arielle R. Gamboa ◽  
Michael Grzenda ◽  
Valeria Saro-Cortes ◽  
...  
Keyword(s):  
Domain Size ◽  
High Shear ◽  
Ambient Conditions ◽  
Immiscible Liquids ◽  
Large Domain ◽  
Emulsion Gel ◽  
Porous Architecture ◽  
Wide Range ◽  
Different Types ◽  
Shear Mixing

<p>To create microporous nanocomposite epoxy thermosets (MiNET), a mixing pathway is demonstrated in which a bicontinuous emulsion gel (bijel) like viscous fluid is kinetically trapped by high shear mixing of immiscible liquids, surfactant, and nanoparticles. The MiNETs are prepared from common ingredients, that are widely employed in industry, including epoxy resin, vegetable oil, epoxidized soybean oil, and different types of nanoparticles such as silica, activated carbon, alumina, and zinc oxide. MiNETs prepared by the presented route are processed at ambient conditions and exhibit low shrinkage (less than 2%). Furthermore, they are suitable to erect macro- to microscale structures with high precision and various porosity. The interconnected porous architecture of MiNET is even preserved in microscale features and thus ensures the mass transport in microstructures. With facile processability and tunability of pore sizes in a wide range (~100 nm to few microns), the proposed route overcomes the two major roadblocks – difficulty in fabrication and large domain size (on the order of 5µm or larger) – of bijel-like materials to apply in catalysis, energy storage, and molecular encapsulation. </p>

Research and Development of Calcium Phosphate Cement

2007 ◽  
Vol 353-358 ◽  
pp. 2267-2270
Author(s):  
Chang Sheng Liu
Keyword(s):  
Calcium Phosphate ◽  
Research And Development ◽  
Calcium Phosphate Cement ◽  
Ambient Conditions ◽  
Hard Tissue ◽  
Shape Characteristic ◽  
Different Types ◽  
Tissue Defects

Hydroxyapatite (HAP)-forming calcium phosphate cement (CPC), due to the high biocompatibility, easy-to-shape characteristic, and the capacity to self-setting under ambient conditions, has been widely used for the repair of hard tissue defects. To satisfy the different clinical need, some modified CPC, including porous CPC, fast-biodegradable CPC, injectable CPC, water-resistant CPC, and rhBMP-2/CPC, have been designed and fabricated in recent years. This paper attempts to give an overview of different types of CPC that have being developed at the present time. Meanwhile, the application perspective of these modified CPC is also explored.

scholarly journals SFCA-II type Ca2.46Fe3+8.57 Fe2+0.52Al5.45O24 – an improved structural model for an iron-ore sinter phase

2021 ◽  
Author(s):  
Volker Kahlenberg ◽  
Hannes Krüger ◽  
Martina Tribus ◽  
Benedikt Anwander
Keyword(s):  
Structural Model ◽  
Site Occupancy ◽  
Type I ◽  
Ambient Conditions ◽  
Charge Balance ◽  
Data Space ◽  
Iron Ore Sinter ◽  
Different Types ◽  
Oriented Parallel ◽  
Atomic Coordinates

AbstractSingle crystals of SFCA-II with composition Ca2.46Fe3+8.57Fe2+0.52Al5.45O24 have been obtained from synthesis experiments in the temperature range between 1300 and 1200 °C. Diffraction experiments at ambient conditions yielded the following basic crystallographic data: space group P$$ \overline{1} $$ 1 ¯ , a = 10.3016(4) Å, b = 10.4656(4) Å, c = 17.9553(6) Å, α = 90.062(3), β = 89.977(3)°, γ = 109.510(3)°, V = 1824.66(12) Å3, Z = 4. Structure determination and subsequent least-squares refinements resulted in a residual of R(|F|) = 0.0349 for 7406 independent reflections and 773 parameters. Site occupancy refinements on the 35 octahedral (M) and tetrahedral (T) positions in the asymmetric unit were aided by crystallochemical considerations and the assumption of charge balance between the cations and anions. The derived formula compares well with the outcome of electron microprobe studies. The crystal structure of SFCA-II shows the typical features of the SFCA-family. It can be built from an alternating sequence of two different types of fundamental layers. For SFCA-II, they are oriented parallel to (100). Layer-type I is solely based on [MO6]-octahedra (M: Ca, Fe3+, Al) forming individual five polyhedra wide bands. Within a single band, the octahedra share common edges. Layer-type II, on the other hand, contains [MO6]-octahedra as well as [TO4]-tetrahedra (T: Al, Fe3+, Fe2+). By corner sharing each [MO6]-group is linked to two adjacent tetrahedra into [MT2O12]-clusters or “winged octahedra”. Linkage between neighboring strips of these moieties is provided by additional [TO4]-tetrahedra arranged in vierer single-chains. Our investigation rectifies previous studies on SFCA-II where wrong atomic coordinates have been published.

scholarly journals IR spectroscopy research of the influence of UV radiation on stabilized polyethylene composites

2020 ◽  
Vol 30 ◽  
pp. 105-112
Author(s):  
E.S. Petukhova ◽  
A.L. Fedorov
Keyword(s):  
Ir Spectroscopy ◽  
Uv Radiation ◽  
Spectroscopy Research ◽  
Polyethylene Composites

Weathering of graffiti spray paint on building stones exposed to different types of UV radiation

2020 ◽  
Vol 236 ◽  
pp. 117736 ◽  
Author(s):  
P. Sanmartín ◽  
J.S. Pozo-Antonio
Keyword(s):  
Uv Radiation ◽  
Building Stones ◽  
Different Types
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