scholarly journals Crosslinking of Polylactide by High Energy Irradiation and Photo-Curing

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4919
Author(s):  
Melania Bednarek ◽  
Katarina Borska ◽  
Przemysław Kubisa
Keyword(s):  
Biomedical Applications ◽  
Uv Light ◽  
High Energy ◽  
Mechanical And Thermal Properties ◽  
Materials Synthesis ◽  
Shape Stability ◽  
Different Types ◽  
Energy Irradiation ◽  
Higher Temperature ◽  
Photo Curing

Polylactide (PLA) is presently the most studied bioderived polymer because, in addition to its established position as a material for biomedical applications, it can replace mass production plastics from petroleum. However, some drawbacks of polylactide such as insufficient mechanical properties at a higher temperature and poor shape stability have to be overcome. One of the methods of mechanical and thermal properties modification is crosslinking which can be achieved by different approaches, both at the stage of PLA-based materials synthesis and by physical modification of neat polylactide. This review covers PLA crosslinking by applying different types of irradiation, i.e., high energy electron beam or gamma irradiation and UV light which enables curing at mild conditions. In the last section, selected examples of biomedical applications as well as applications for packaging and daily-use items are presented in order to visualize how a variety of materials can be obtained using specific methods.

Observation of intrinsic emission in β-BiNbO4 available for excitation of both UV light and high energy irradiation

2016 ◽  
Vol 18 (34) ◽  
pp. 23702-23708 ◽  
Author(s):  
Ruijin Yu ◽  
Aiping Fan ◽  
Maosen Yuan ◽  
Tianbao Li ◽  
Jinyi Wang
Keyword(s):  
Room Temperature ◽  
Uv Light ◽  
High Energy ◽  
Optical Transitions ◽  
X Ray ◽  
Energy Irradiation ◽  
Intrinsic Emission ◽  
High Energy Irradiation

β-BiNbO4 shows photoluminescence and scintillation emission at room temperature. The excitation is from optical transitions from NbO67− groups and 6s(Bi)–4d(Nb) MMCT states; the intrinsic emission is from 3P1 → 1S0 transitions of Bi3+ ions under UV light and X-ray excitation.

A high-density nanowire electrode on paper for biomedical applications

RSC Advances ◽  
2015 ◽  
Vol 5 (12) ◽  
pp. 8680-8687 ◽  
Author(s):  
P. Mostafalu ◽  
S. Sonkusale
Keyword(s):  
Biomedical Applications ◽  
High Density ◽  
Different Types ◽  
Paper Substrates

Different types of nanowires made from platinum, nickel and copper are fabricated and patterned with microscale resolution on paper substrates and employed for biomedical applications.

Shape-Tailored TiO2 Photocatalysts Obtained in the Presence of Different Types of Carbon Materials

2021 ◽  
Vol 21 (4) ◽  
pp. 2360-2367
Author(s):  
Krisztina Vajda ◽  
Klára Hernádi ◽  
Cosmin Coteţ ◽  
Gábor Kovács ◽  
Zsolt Pap
Keyword(s):  
Carbon Materials ◽  
Uv Light ◽  
Carbon Aerogel ◽  
Low Carbon ◽  
Negative Effects ◽  
Tio2 Photocatalysts ◽  
Uv Light Irradiation ◽  
Specific Morphology ◽  
Different Types ◽  
Photocatalytic Applications

Titania and carbon materials are intensively studied in composite materials including photocatalytic applications. Both positive and negative effects were described in the literature, including charge separation, adsorption enhancement and short-circuiting of the photoelectrons as well. In the present study a more sparsely investigated properties of carbon materials will be highlighted, namely their role as crystallization promoters for titania, during hydrothermal synthesis of the composites. Therefore, carbon nanotubes, carbon coils, activated carbon, graphite and carbon aerogel was used to identify the importance of carbon during the time dependent crystallization of titanium dioxide. The crystal phase composition, morphology, optical properties and photocatalytic activity was followed, and it was found that the anatase and rutile crystallization depended on the used carbon material. The morphology of the particles varied from single anatase sheet-like crystals to hierarchical microball-like structures, while in some cases no specific morphology was observed. Furthermore, it was found that despite the low carbon content (2 wt.%) and microcrystalline structure of TiO2 the composites were proven to be efficient in the degradation of Rhodamine B under UV light irradiation.

Mechanical Characterization of UV Photopolymerized PMMA with Different Photo-Initiator Concentration

2021 ◽  
Vol 903 ◽  
pp. 11-16
Author(s):  
M.A. Manjunath ◽  
K. Naveen ◽  
Prakash Vinod ◽  
N. Balashanmugam ◽  
M.R. Shankar
Keyword(s):  
Mechanical Properties ◽  
Light Source ◽  
Polymethyl Methacrylate ◽  
Biomedical Applications ◽  
Mechanical Characterization ◽  
Uv Light ◽  
Curing Time ◽  
Uv Led ◽  
Pmma Resin

Polymethyl methacrylate (PMMA) is one among few known photo-polymeric resin useful in lithography for fabricating structures having better mechanical properties to meet the requirement in electronics and biomedical applications. This study explores the effect of Photo Initiator (PI) concentration and also curing time on strength and hardness of Polymethyl methacrylate (PMMA) obtained by UV photopolymerization of Methyl methacrylate (MMA) monomer. The UV LED light source operating at the wavelength of 364 nm is used with Benzoin Ethyl Ether (BEE) as photo initiator. The curing of PMMA resin is supported with peltier cooling device placed at the bottom of the UV light source. The characterisation study of UV photo cured PMMA is analysed through nano indenter (Agilent Technologies-G200). The current work investigates the influence of PI concentration and curing time in achieving maximum mechanical properties for UV photopolymerized PMMA.

scholarly journals Temporal Evolution of the High-energy Irradiation and Water Content of TRAPPIST-1 Exoplanets

2017 ◽  
Vol 154 (3) ◽  
pp. 121 ◽  
Author(s):  
V. Bourrier ◽  
J. de Wit ◽  
E. Bolmont ◽  
V. Stamenković ◽  
P. J. Wheatley ◽  
...  
Keyword(s):  
Water Content ◽  
Temporal Evolution ◽  
High Energy ◽  
Energy Irradiation ◽  
High Energy Irradiation

RBS/Channeling Diffusion Studies of High Energy Au Implanted Mg Single Crystals

1991 ◽  
Vol 235 ◽  
Author(s):  
R. C. Da Selva ◽  
M. F. Da Silva ◽  
L. Thomé ◽  
A. A. Melo ◽  
J. C. Soares
Keyword(s):  
Single Crystals ◽  
Temperature Regime ◽  
High Energy ◽  
Back Diffusion ◽  
Thermally Activated ◽  
Diffusion Studies ◽  
Higher Temperature ◽  
Diffusion Behaviour ◽  
Thermally Activated Process

ABSTRACTRBS/channeling analyses of high energy Au implantation into Mg are presented. The diffusion behaviour of Au was studied and the occurrence of essentially two distinct regimes were observed: the segregation regime at lower temperatures correlated with the damage introduced by the high energy implantation and the higher temperature regime as a normal thermally activated process of back-diffusion.

Heavy Fluoride Glasses as an Alternative to Crystals in High Energy Physics Calorimetry

1994 ◽  
Vol 348 ◽  
Author(s):  
I. Dafinei ◽  
E. Auffray ◽  
P. Lecoq ◽  
M. Schneegans
Keyword(s):  
High Energy Physics ◽  
Low Cost ◽  
High Energy ◽  
Attractive Alternative ◽  
Close Collaboration ◽  
Fluoride Glasses ◽  
Different Types ◽  
Electromagnetic Calorimeters ◽  
Physics Experiments ◽  
Energy Physics

ABSTRACTIn the quest for low cost scintillators to equip the very large electromagnetic calorimeters for future High Energy Physics experiments, scintillating glasses can offer an attractive alternative to crystals. The expected production price is indeed supposed to be reduced as compared to crystals, especially for very large volumes. An intense R&D effort has been made by the Crystal Clear collaboration to develop heavy scintillating fluoride glasses in close collaboration with the industry. Results will be shown on the fluorescence and scintillation properties as well as on the radiation resistance of different types of fluoride glasses. Ideas about possible improvement of present performances will also be given.

scholarly journals Visible Light-Enabled Paternò-Büchi Reaction via Triplet Energy Transfer for the Synthesis of Oxetanes

2020 ◽  
Author(s):  
Katie Rykaczewski ◽  
Corinna Schindler
Keyword(s):  
Energy Transfer ◽  
Visible Light ◽  
Uv Light ◽  
Cycloaddition Reaction ◽  
High Energy ◽  
Triplet Energy ◽  
Reaction Conditions ◽  
Triplet Energy Transfer

<div> <p>One of the most efficient ways to synthesize oxetanes is the light-enabled [2+2] cycloaddition reaction of carbonyls and alkenes, referred to as the Paternò-Büchi reaction. The reaction conditions for this transformation typically require the use of high energy UV light to excite the carbonyl, limiting the applications, safety, and scalability. We herein report the development of a visible light-mediated Paternò-Büchi reaction protocol that relies on triplet energy transfer from an iridium-based photocatalyst to the carbonyl substrates. This mode of activation is demonstrated for a variety of aryl glyoxylates and negates the need for both, visible light-absorbing carbonyl starting materials or UV light to enable access to a variety of functionalized oxetanes in up to 99% yield.</p> </div> <br>

scholarly journals A lightweight magnetic gripper for an aerial delivery vehicle: design and applications

ACTA IMEKO ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 61
Author(s):  
Giuseppe Sutera ◽  
Dario Calogero Guastella ◽  
Giovanni Muscato
Keyword(s):  
Energy Consumption ◽  
Permanent Magnets ◽  
High Energy ◽  
Vehicle Design ◽  
Delivery Vehicle ◽  
Delivery Service ◽  
Remote Areas ◽  
Different Types ◽  
Robot Systems ◽  
High Energy Consumption

<p>In recent years, drones have become widely used in many fields. Their vertical flight capability makes these systems suitable for carrying out a variety of tasks. In this paper, the delivery service they provide is analysed. The delivery of goods quickly and to remote areas is a relevant application scenario; however, the systems proposed in the literature use electromagnets, which affect the duration of the flight. In addition, these devices are heavy and suffer from high energy consumption, which reduces the maximum transportable payload. This study proposes a new lightweight magnetic plate composed of permanent magnets, capable of collecting and positioning any object as long as it has a ferromagnetic surface on the top. This plate was developed for the Mohamed Bin Zayed International Robotics Challenge 2020, an international robotics competition for multi-robot systems. Challenge two of this competition required a drone capable of picking up different types of bricks and assembling them to build a wall according to an assigned pattern. The bricks were of different colours and sizes, with weights ranging from 1 to 2 kg. In light of this, it was concluded that weight was the most relevant specification to consider in drone design.</p>

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