scholarly journals New materials used for the consolidation of archaeological wood–past attempts, present struggles, and future requirements

2012 ◽  
Vol 13 (3) ◽  
pp. S183-S190 ◽  
Author(s):  
Mikkel Christensen ◽  
Hartmut Kutzke ◽  
Finn Knut Hansen
Keyword(s):  
New Materials ◽  
Archaeological Wood ◽  
Materials Used

Possible Causes in Breaking of Dental Implants Research

2017 ◽  
Vol 907 ◽  
pp. 104-118
Author(s):  
Maria Stoicănescu ◽  
Eliza Buzamet ◽  
Dragos Vladimir Budei ◽  
Valentin Craciun ◽  
Roxana Budei ◽  
...  
Keyword(s):  
Dental Implants ◽  
Dental Implant ◽  
Scientific Literature ◽  
Surface Characteristics ◽  
Raw Material ◽  
New Materials ◽  
Materials Used ◽  
Type Of Failure ◽  
First Time ◽  
Consequent Increase

Dental implants are becoming increasingly used in current dental practice. This increased demand has motivated manufacturers to develop varieties of product through design, but also looking for new materials used to improve surface characteristics in order to obtain a better osseointegration. But the increase in the use of implants goes to a consequent increase in the number of failures. These failures are caused either by treatment complications (peri-implantitis), by fatigue breakage under mechanical over-stress, by defective raw material, or due to errors during the insertion procedures. Although they are rare, these complications are serious in dentistry. Before to market a dental implant to clinical practitioners, the product is validated among other determinations in number of biocompatibility research. Raw material issues, details about its structure and properties are less published by the scientific literature, but all this are subject of a carefully analysis of the producers. Breaking of dental implants during surgical procedures, during the prosthetic procedures or during use (chewing, bruxism, accidents, etc.), is the second most common cause of loss of an implant after consecutive peri-implantitis rejection. Although the frequency of this type of failure for a dental implant is much smaller than those caused by the peri-implantitis, a detailed study of broken implants can explain possible causes. The use of scanning electron microscopy (SEM) in the study of the cleave areas explain the production mechanism of cleavages, starting from micro-fissures in the alloy used for the production of dental implants. These micro-fissures in weak areas of the implant (anti-rotational corners of the polygons, etc.) could generate a serious risk of cleavage first time when a higher force is applied.

scholarly journals Essential Oils as Alternative Biocides for the Preservation of Waterlogged Archaeological Wood

2020 ◽  
Vol 8 (12) ◽  
pp. 2015
Author(s):  
Federica Antonelli ◽  
Marco Bartolini ◽  
Marie-Laure Plissonnier ◽  
Alfonso Esposito ◽  
Giulia Galotta ◽  
...  
Keyword(s):  
Essential Oils ◽  
Inhibitory Concentration ◽  
Treated Wood ◽  
Biological Degradation ◽  
Archaeological Wood ◽  
Waterlogged Archaeological Wood ◽  
Materials Used ◽  
And Storage ◽  
Generation Sequencing

Waterlogged archaeological wood is exposed to a high risk of biological degradation during the post-excavation phases of storage and restoration. For this reason, often biocides must be used to preserve wooden remains. In the present work three essential oils (cinnamon, wild thyme, and common thyme) were tested as possible alternative biocides to use in the preservation of waterlogged archaeological wood. The oils were first tested in vitro to establish the minimum inhibitory concentration (MIC) and to evaluate the biocidal activity on selected fungal strains. Then, the established MIC was applied on waterlogged archaeological wood samples and during an actual restoration treatment. The effectiveness of the oils was evaluated through cultural analyses, ATP quantification, and next-generation sequencing. The results showed that the oils caused a significant decrease in the vitality of fungal mycelia grown in vitro and of the microbiota present in treated wood and storage water. Furthermore, an influence on the composition of the bacterial communities of treated wood samples was observed. Although further tests are needed to evaluate interferences with the materials used during restoration procedures, essential oils could be considered as a possible alternative to the currently used biocide.

scholarly journals Synthesis and characterisation of lignin-like oligomers as a bio-inspired consolidant for waterlogged archaeological wood

2016 ◽  
Vol 88 (10-11) ◽  
pp. 969-977 ◽  
Author(s):  
Emily McHale ◽  
Susan Braovac ◽  
Calin C. Steindal ◽  
Richard B. Gillis ◽  
Gary G. Adams ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Ethyl Acetate ◽  
Cell Walls ◽  
Water Soluble ◽  
Wood Structure ◽  
New Materials ◽  
Archaeological Wood ◽  
Waterlogged Archaeological Wood ◽  
Maximum Water ◽  
Maximum Water Content

AbstractThe development of new materials for the consolidation of waterlogged archaeological wood from sustainable sources is an important area of research, as the most widely used consolidant today is petroleum based. Ideally a new consolidant will interact with the existing wood structure, ensuring maximum compatibility. Lignin is often the major component remaining in archaeological wood, as it is less susceptible to degradation than holocellulose. Therefore, in order to maximise the potential for interaction with the wood cells, lignin-like oligomers have been synthesized from isoeugenol using a water soluble copper salen catalyst at pH 10, giving a weight average Mw of 1.6 kDa. Analysis by NMR spectroscopy has shown that the oligomers have a lignin-like structure with β-O-4′, β-β′ and β-5′ connections. A 10 w/w% solution of the oligomers in ethyl acetate was found to thoroughly penetrate 1 cm3 samples of waterlogged archaeological wood (density of 0.146 g/mL, maximum water content of 620%) after 14 days impregnation, as determined by FTIR spectroscopy. No impregnation material could be seen by SEM, suggesting that it coats the cell walls upon drying. This indicates that dehydrogenated polymers penetrate waterlogged archaeological wood well and have the potential to be developed into consolidants.

NEW MATERIALS USED AS OPTICAL WINDOW IN THIN FILM SOLAR CELLS

2002 ◽  
Vol 09 (05n06) ◽  
pp. 1675-1680 ◽  
Author(s):  
G. GORDILLO
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Thin Film Solar Cells ◽  
Morphological Properties ◽  
New Materials ◽  
Optical Window ◽  
Force Microscopy ◽  
Atomic Force ◽  
Window Systems ◽  
Materials Used

The purpose of this work is to investigate new materials which present good properties to be used as optical window and buffer layer in thin film solar cells based on CdTe and CuInSe 2. As potential candidates for optical windows, two different bilayer systems were studied: ZnO/In x Se y and ZnO/ZnSe. They are planned to be used later in the fabrication of solar cells with structures CuInSe 2/ In x Se y/ ZnO and ZnO/ZnSe/CdTe. The methods used to prepare the different window materials, as well as the technological stages of the solar cell fabrication, will be described. Additionally, the optical and morphological properties of the window systems will be studied through transmittance and atomic force microscopy (AFM) measurements. Preliminary results obtained with Cu(In,Ga)Se 2 solar cells, fabricated using ZnO/In x Se y as optical window, will be reported. They will be compared with those obtained using ZnO/CdS as optical window, which is regularly used in this type of cells.

scholarly journals Optimization of thermal efficiency of a parabolic trough solar collector (PTSC) based on new materials application for the absorber tube selective coating and glass cover

2018 ◽  
Vol 16 (5) ◽  
Author(s):  
Hamzeh Jamali
Keyword(s):  
Thermal Efficiency ◽  
Material Selection ◽  
New Materials ◽  
Selective Coating ◽  
Glass Cover ◽  
Optical And Mechanical Properties ◽  
Materials Used ◽  
Heat Transfers ◽  
Parabolic Trough Solar Collector

This article aims to demonstrate a solution in order for an optimization of PTSCs thermal efficiency. The solution focuses on the radiative heat transfers occurring within the absorber tube of a PTSC unit of a solar power plant situated in Shiraz, Iran as the paper case study. Since the existing heat transfers procedure all comes down to the optical properties of the materials used in the absorber tube of a PTSC unit, an ideal material selection can directly influence the heat transfers and consequently improve the thermal efficiency of a PTSC unit to a great extent. This paper comes up with new materials selection in which graphene nanostructure and BOROFLOAT 33 are respectively used as absorber tube coating and absorber tube glass cover for their exceptional optical and mechanical properties. Meanwhile, a numerical and analytical comparison is made between the thermal efficiencies of a PTSC unit in different states.

scholarly journals Problems of Increasing the Biocompatibility of Materials Used in Medicine

2021 ◽  
Vol 8 (7) ◽  
pp. 419
Author(s):  
Marufjon Mukhtorovich Mamajonov ◽  
Pavel Evgenievich Lushchik ◽  
Murodjon Turgunbaevich Botirov ◽  
Yuri Gennadievich Alekseev
Keyword(s):  
Mechanical Properties ◽  
Physicochemical Properties ◽  
Medical Devices ◽  
Rapid Development ◽  
Science And Technology ◽  
Modern Literature ◽  
New Materials ◽  
Advantages And Disadvantages ◽  
Materials Used ◽  
Modern Technologies

A review of modern literature on the development of biocompatible implants based on modern technologies, including bioengineering and nanostructuring, is presented. The advantages and disadvantages of implants based on metals and alloy, ways of improving their biological and mechanical properties are shown. In connection with the rapid development of many branches of science and technology, as well as in medicine, the problem arose of obtaining new materials, in particular, alloys with valuable physicochemical properties, which are used for the implant of cardiology, traumatology, orthopedics and other industries. Study of biocompatibility of medical devices based on metals and alloys, search for ways to overcome the low engraftability of implanted structures.

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