2,463 results match your criteria insulating properties

Ion Exchange Lithography: Localized Ion Exchange Reactions for Spatial Patterning of Perovskite Semiconductors and Insulators.

Adv Mater 2021 Apr 12:e2005291. Epub 2021 Apr 12.

AMOLF, Science Park 104, Amsterdam, 1098 XG, The Netherlands.

Patterning materials with different properties in a single film is a fundamental challenge and essential for the development of next-generation (opto)electronic functional components. This work introduces the concept of ion exchange lithography and demonstrates spatially controlled patterning of electrically insulating films and semiconductors with tunable optoelectronic properties. In ion exchange lithography, a reactive nanoparticle "canvas" is locally converted by printing ion exchange "inks. Read More

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Environmental conditions but not nest composition affect reproductive success in an urban bird.

Ecol Evol 2021 Apr 12;11(7):3084-3092. Epub 2021 Mar 12.

Department of Biodiversity, Ecology and Evolution Universidad Complutense de Madrid Madrid Spain.

Adjusting the composition of their nests, breeding birds can influence the environmental conditions that eggs and offspring experience. Birds often use feathers to build nests, presumably due to their insulating properties. The amount of feathers in nests is often associated with increased nestling survival and body condition. Read More

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Optical Properties of the Infinite-Layer La_{1-x}Sr_{x}NiO_{2} and Hidden Hund's Physics.

Phys Rev Lett 2021 Mar;126(12):127401

Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08856, USA.

We investigate the optical properties of the normal state of the infinite-layer La_{1-x}Sr_{x}NiO_{2} using density functional theory plus dynamical mean-field theory. We find a correlated metal which exhibits substantial transfer of spectral weight to high energies relative to the density functional theory. The correlations are not due to Mott physics, which would suppress the charge fluctuations and the integrated optical spectral weight as we approach a putative insulating state. Read More

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Self-reinforced poly(ether ether ketone) and polyethylene composite gaskets for prevention of mechanically-assisted corrosion in modular taper junctions: Seating, micromotion and short-term fretting corrosion.

J Mech Behav Biomed Mater 2021 Mar 27;119:104454. Epub 2021 Mar 27.

Syracuse Biomaterials Institute, Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, NY, 13244, USA; Clemson Department of Bioengineering, USA; Clemson - Medical University of South Carolina Bioengineering Program, USA. Electronic address:

Mechanically-assisted crevice corrosion (MACC) is a phenomenon known to cause complications in modular orthopedic implants, particularly at metal-metal taper junctions. Previous studies of the properties and corrosion performance of an interfacial polymeric self-reinforced composite (SRC) gaskets have shown its capability as a high-strength, insulating barrier against oxide abrasion and metal degradation of metal-metal (or metal-hard) contacts in MACC conditions. This study characterizes the short-term tribocorrosion performance of poly (ether ether ketone) SRCs (SRC-PEEK) and polyethylene SRC (SRC-PE) films under in vitro test conditions for head-neck modular junction designs in hip replacement devices. Read More

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Magnetic Texture in Insulating Single Crystal High Entropy Oxide Spinel Films.

ACS Appl Mater Interfaces 2021 Apr 6. Epub 2021 Apr 6.

Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.

Magnetic insulators are important materials for a range of next-generation memory and spintronic applications. Structural constraints in this class of devices generally require a clean heterointerface that allows effective magnetic coupling between the insulating layer and the conducting layer. However, there are relatively few examples of magnetic insulators that can be synthesized with surface qualities that would allow these smooth interfaces and precisely tuned interfacial magnetic exchange coupling, which might be applicable at room temperature. Read More

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Direct Detection of Circularly Polarized Light Using Chiral Copper Chloride-Carbon Nanotube Heterostructures.

ACS Nano 2021 Apr 6. Epub 2021 Apr 6.

Materials Science Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States.

The emergent properties of chiral organic-inorganic hybrid materials offer opportunities in spin-dependent optoelectronic devices. One of the most promising applications where spin, charge, and light are strongly coupled is circularly polarized light (CPL) detection. However, the performance of state-of-the-art CPL detectors using chiral hybrid metal halide semiconductors is still limited by the low anisotropy factor, poor conductivity, and limited photoresponsivity. Read More

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Hexagonal Boron Nitride Crystal Growth from Iron, a Single Component Flux.

ACS Nano 2021 Apr 5. Epub 2021 Apr 5.

Tim Taylor Department of Chemical Engineering, Kansas State University, Manhattan, Kansas 66506, United States.

The highest quality hexagonal boron nitride (hBN) crystals are grown from molten solutions. For hBN crystal growth at atmospheric pressure, typically the solvent is a combination of two metals, one with a high boron solubility and the other to promote nitrogen solubility. In this study, we demonstrate that high-quality hBN crystals can be grown at atmospheric pressure using pure iron as a flux. Read More

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Thickness-Dependent Band Gap Modification in BaBiO.

Nanomaterials (Basel) 2021 Mar 30;11(4). Epub 2021 Mar 30.

MESA+ Institute for Nanotechnology, University of Twente, 7500 AE Enschede, The Netherlands.

The material BaBiO3 is known for its insulating character. However, for thin films, in the ultra-thin limit, metallicity is expected because the oxygen octahedra breathing mode will be suppressed as reported recently. Here, we confirm the influence of the oxygen breathing mode on the size of the band gap. Read More

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Sustainable Lightweight Insulation Materials from Textile-Based Waste for the Automobile Industry.

Materials (Basel) 2021 Mar 5;14(5). Epub 2021 Mar 5.

Institute for Frontier Materials, Deakin University, Geelong, VIC 3216, Australia.

Globally, automotive manufacturers are looking for ways to produce environmentally sustainable and recyclable materials for automobiles to meet new regulations and customer desires. To enable the needs for rapid response, this study investigated the feasibility of using waste and virgin wool fibres as cost-effective and sustainable alternatives for automotive sound and heat insulation using a chemical-free approach. Several properties of the currently available commercial automotive insulators were investigated in order to facilitate the designing of green wool-based needle-punched nonwoven materials. Read More

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Durability of Thermal Renders with Lightweight and Thermal Insulating Aggregates: Regranulated Expanded Cork, Silica Aerogel and Expanded Polystyrene.

Gels 2021 Mar 25;7(2). Epub 2021 Mar 25.

CERIS, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.

Following the trend of energy-efficient construction, renders with thermal insulation properties have been studied for replacing conventional renders. However, there are still few studies on the durability of these renders that may become a barrier for their implementation. In this study, the performance of lightweight renders for thermal insulation to accelerated aging cycles and freeze/thaw cycles is discussed. Read More

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Effects of Physical and Chemical Modification of Sunflower Cake on Polyurethane Composite Foam Properties.

Materials (Basel) 2021 Mar 15;14(6). Epub 2021 Mar 15.

Institute of Polymer & Dye Technology, Lodz University of Technology, 90-924 Lodz, Poland.

Sunflower cake (SC), which is waste during the production of sunflower oil, was selected as a modifier of properties in polyurethane (PUR) foams. The SC was chemically modified with triphenylsilanol (SC_S) and physically modified with rapeseed oil (SC_O). The influence of SC on the rheological properties of the polyol and the kinetics of foam growth were investigated. Read More

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Improved Breakdown Strength of Polypropylene Film by Polycyclic Compounds Addition for Power Capacitors.

Materials (Basel) 2021 Mar 3;14(5). Epub 2021 Mar 3.

Key Laboratory of Smart Grid of Education Ministry, School of Electrical and Information Engineering, Tianjin University, Tianjin 300072, China.

In this paper, an improved method for the electric performance of polypropylene (PP) film was proposed to promote the safety and stability of power capacitors. Modified PP films containing three different polycyclic compounds were prepared, which showed good thermal properties and decreased DC conductivity. The DC breakdown strength of the modified PP films under both positive and negative voltage is increased compared with that of the original film. Read More

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Thermal Conductivity Analysis of Chitin and Deacetylated-Chitin Nanofiber Films under Dry Conditions.

Nanomaterials (Basel) 2021 Mar 8;11(3). Epub 2021 Mar 8.

The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki-shi, Osaka 567-0047, Japan.

Chitin, a natural polysaccharide polymer, forms highly crystalline nanofibers and is expected to have sophisticated engineering applications. In particular, for development of next-generation heat-transfer and heat-insulating materials, analysis of the thermal conductivity is important, but the thermal conductivity properties of chitin nanofiber materials have not been reported. The thermal conductivity properties of chitin nanofiber materials are difficult to elucidate without excluding the effect of adsorbed water and analyzing the influence of surface amino groups. Read More

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Maximizing Oxygen Evolution Performance on a Transparent NiFeO/TaN Photoelectrode Fabricated on an Insulator.

ACS Appl Mater Interfaces 2021 Apr 2. Epub 2021 Apr 2.

Department of Chemical System Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, Japan.

A transparent TaN photoanode is a promising candidate for the front-side photoelectrode in a photoelectrochemical (PEC) cell with tandem configuration (tandem cell), which can potentially provide high solar-to-hydrogen (STH) energy conversion efficiency. This study focuses in particular on the semiconductor properties and interfacial design of transparent TaN photoanodes fabricated on insulating quartz substrates (TaN/SiO), typically the geometric area of 1 × 1 cm in contact with indium on its edge. This material utilizes the self-conductivity of TaN to make the PEC system operational, and the electrode would strongly reflect the intrinsic nature of TaN without a back contact that is commonly introduced. Read More

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Competitive adsorption of residual polyvinylpyrrolidone and detection molecular on flower liked silver nanoparticles.

Spectrochim Acta A Mol Biomol Spectrosc 2021 Mar 23;255:119717. Epub 2021 Mar 23.

College of Optical and Electronic Technology, China Jiliang University, 310018 Hangzhou, China. Electronic address:

The silver nanoparticles have been frequently used in SERS detection, for their unique optical properties and sensitive surface Raman enhancement properties. However, as the preparation of silver nanoparticles will use polyvinylpyrrolidone (PVP) to achieve the effect of reducing agent and surfactant, the surface of the prepared silver nanoparticles will be wrapped by PVP, forming an insulating layer and an ill-defined AgNPs interface, which limits the plasmonic coupling between the laminates of AgNPs. This paper reported a simple method to remove PVP for high performance and reusable SERS substrate, and the residue of PVP was studied after clean centrifugal by ethanol or water. Read More

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Topological protection versus degree of entanglement of two-photon light in photonic topological insulators.

Nat Commun 2021 Mar 30;12(1):1974. Epub 2021 Mar 30.

Max-Born-Institut, Berlin, Germany.

Topological insulators combine insulating properties in the bulk with scattering-free transport along edges, supporting dissipationless unidirectional energy and information flow even in the presence of defects and disorder. The feasibility of engineering quantum Hamiltonians with photonic tools, combined with the availability of entangled photons, raises the intriguing possibility of employing topologically protected entangled states in optical quantum computing and information processing. However, while two-photon states built as a product of two topologically protected single-photon states inherit full protection from their single-photon "parents", a high degree of non-separability may lead to rapid deterioration of the two-photon states after propagation through disorder. Read More

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Characterization of carrier behavior in photonically excited 6H silicon carbide exhibiting fast, high voltage, bulk transconductance properties.

Sci Rep 2021 Mar 25;11(1):6859. Epub 2021 Mar 25.

Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA, 94551, USA.

Unabated, worldwide trends in CO production project growth to > 43-BMT per year over the next two decades. Efficient power electronics are crucial to fully realizing the CO mitigating benefits of a worldwide smart grid (~ 18% reduction for the United States alone). Even state-of-the-art SiC high voltage junction devices are inefficient because of slow transition times (~ 0. Read More

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Highly compressible, heat-insulating and self-extinguishing cellulose nanofiber/aramid nanofiber nanocomposite foams.

Carbohydr Polym 2021 Jun 19;261:117837. Epub 2021 Feb 19.

College of Bioresources Chemical and Materials Engineering, Shaanxi Provincial Key Laboratory of Papermaking Technology and Specialty Paper Development, National Demonstration Center for Experimental Light Chemistry Engineering Education, Shaanxi University of Science & Technology, Xi'an, 710021, China.

Foam as a kind of burgeoning materials with laminated porous 3D structure was realized multifunctional application in diversified fields. In this work, we aimed to prepare a highly compressible and self-extinguishing multifunctional nanocomposite foam with anisotropic porous 3D structure through a green aqueous freeze-drying method. In order to address the inflammable property and brittleness issue of high-loading cellulose nanofiber foam, aramid nanofiber was incorporated into cellulose nanofiber framework, forming the multicomponent and multilevel honeycomb structure of the nanocomposite foam. Read More

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Functionalized CNTs with DOPO and Silicon Containing Agents: Effective Reinforcer for Thermal and Flame Retardant Properties of Polystyrene Nanocomposites.

Front Chem 2020 10;8:627642. Epub 2021 Feb 10.

Beijing Key Lab of MFPTS, China Academy of Safety Science and Technology, Beijing, China.

DOPO and silicon containing agents modified multiwalled carbon nanotubes (MCNTs) were synthesized through sol-gel process and MCNTs are introduced into polystyrene (PS) through polymerization. TEM observations and FTIR results of MCNTs demonstrated that the MCNT nanofillers were coated with the organic/inorganic flame retardant compound. Moreover, the TEM results of the composites indicate that MCNTs dispersed in polystyrene PS matrix uniformly due to the modification. Read More

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February 2021

Atomic Force Microscopy: Single-Molecule Imaging and Force Spectroscopy in the Study of Flavoproteins Ligand Binding and Reaction Mechanisms.

Methods Mol Biol 2021 ;2280:157-178

Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, Universidad de Zaragoza, Zaragoza, Spain.

Atomic force microscopy (AFM) is one of the most versatile tools currently used in nanoscience. AFM allows for performing nondestructive imaging of almost any sample in either air or liquid, regardless whether the specimen is insulating, conductive, transparent, or opaque. It also allows for measuring interaction forces between a sharp probe and a sample surface, therefore allowing to probe nanomechanical properties of the specimen by either applying a controlled force or pulling the sample. Read More

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January 2021

Experimental evaluation of bamboo fiber/particulate coconut shell hybrid PVC composite.

Sci Rep 2021 Mar 9;11(1):5465. Epub 2021 Mar 9.

Department of Mechanical Engineering, Landmark University, PMB, Omu-Aran, 1001, Kwara State, Nigeria.

Bamboo fibers (BF) treated in 1.3 Molar NaOH and particulate coconut shell (PCS) sieved to - 45 µm were incorporated into polyvinyl chloride (PVC) matrix towards improving the properties of PVC composite for ceiling boards and insulating pipes which sags and degrade with time needing improvement in properties. The process was carried out via compression moulding applying 0. Read More

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Actuator Performance of Dielectric Elastomers Comprising Hydrogenated Carboxylated Acrylonitrile-Butadiene Rubber/Nitrile Group-Modified Titanium Oxide Particles.

ACS Omega 2021 Mar 4;6(10):6965-6972. Epub 2021 Mar 4.

Institute for Materials Chemistry and Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan.

We prepared a dielectric elastomer actuator composed of hydrogenated carboxylated acrylonitrile-butadiene rubber (HXNBR)/nitrile group (CN)-modified and non-modified titanium oxide (TiO) particles with insulation properties. The CN group-containing silane coupling agent was synthesized via a thiol-ene reaction between acrylonitrile and 3-mercaptpropyltrimethoxysilane and immobilized onto the TiO particle surface. The HXNBR/CN-modified and non-modified TiO particle composite elastomer showed a high relative dielectric constant and generated stress in a low electric field. Read More

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Correlation driven topological nodal ring ferromagnetic spin gapless semimetal: CsMnF.

J Phys Condens Matter 2021 Mar 18. Epub 2021 Mar 18.

Department of Physics, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, Hyderabad, Telangana, 502285, INDIA.

The observation of in-plane ferromagnetism in layered magnetic materials in conjunction with the topological nodal-ring dispersion in a spin gapless semimetal (SGS) with 100 % spin polarization has a fertile ground for novel physics, rich scientific significance and for the next-generation advanced spintronic and topological devices. Topological nodal ring spin gapless semimetals (TNRSGSM) with large band gap in the other spin channel prevents the spin leakage and are excellent spintronic materials. On the basis of density functional theory (DFT), we have studied the layered magnetic perovskite, CsMnFwhich is predicted to be a ferromagnetic insulator though the fellow compounds like AMnF(A = Na, K, Rb) are anti-ferromagnetic in nature. Read More

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Pentagonal B2N3-Based 3D Metallic Boron Nitride with High Energy Density.

J Phys Condens Matter 2021 Mar 18. Epub 2021 Mar 18.

Center for Applied Physics and Technology, Peking University, 5 Yiheyuan Road, Beijing, 100871, CHINA.

Different from conventional insulating or semiconducting boron nitride, metallic BN has received increasing attention in recent years because of its intrinsically high electric conductivity and its potential for broad applications. In this study, by assembling the experimentally synthesized pentagonal B2N3 units, we have proposed the first pentagon-based three dimensional (3D) metallic boron nitride, labelled penta-B4N7. First-principles calculations together with molecular dynamics simulations and convex hull diagram show that penta-B4N7 is not only thermally, dynamically and mechanically stable, but also three-dimensionally metallic. Read More

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Switchable dual-band to broadband terahertz metamaterial absorber incorporating a VO phase transition.

Opt Express 2021 Feb;29(4):5437-5447

We design and demonstrate a thermally switchable terahertz metamaterial absorber consisting of an array of orthogonal coupled split-ring metal resonators involving a VO phase transition. Numerical results indicate that the active metamaterial always absorbs the TE wave in dual-band regardless of insulating and metallic VO, while the insulator-to-metal phase transition enables a switchable effect between dual-band and broadband absorption of the TM wave with the resonant frequency tunability of 33%. Especially under the metallic VO state, the absorption properties are polarization-dependent and exhibit a switching effect between dual-band and broadband absorption with the increase of the polarization angle. Read More

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February 2021

Contrasting recruitment of skin-associated adipose depots during cold challenge of mouse and human.

J Physiol 2021 Mar 16. Epub 2021 Mar 16.

McArdle Laboratory for Cancer Research, University of Wisconsin-Madison.

Key Points: Several distinct strategies produce and conserve heat to maintain body temperature of mammals, each associated with unique physiologies, with consequence for wellness and disease susceptibility Highly regulated properties of skin offset the total requirement for heat production  We hypothesize that the adipose component of skin is primarily responsible for modulating heat flux; here we evaluate the relative regulation of adipose depots in mouse and human, to test their recruitment to heat production and conservation We found that insulating mouse dermal white adipose tissue accumulates in response to environmentally- and genetically-induced cool stress; this layer is one of two adipose depots closely apposed to mouse skin, where the subcutaneous mammary gland fat pads are actively recruited to heat production In contrast, the body-wide adipose depot associated with human skin produces heat directly, potentially creating an alternative to the centrally regulated brown adipose tissue ABSTRACT: Mammalian skin impacts metabolic efficiency system-wide, controlling the rate of heat loss and consequent heat production. Here we compare the unique fat depots associated with mouse and human skin, to determine whether they have corresponding function and regulation. For human, we assay a skin-associated fat (SAF) body-wide depot to distinguish it from the subcutaneous fat pads characteristic of abdomen and upper limbs. Read More

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Strategic Customization of Polymeric Nanocomposites Modified by 2D Titanium Oxide Nanosheet for High-k and Flexible Gate Dielectrics.

Small 2021 Mar 14:e2007213. Epub 2021 Mar 14.

Thin Film Materials Research Center, Korea Research Institute of Chemical Technology (KRICT), 141 Gajeong-ro, Yuseong-gu, Daejeon, 34114, Republic of Korea.

Organic polymer-based dielectrics with intrinsic mechanical flexibility and good processability are excellent candidates for the dielectric layer of flexible electronics. These polymer films can become even more rigid and electrically robust when modified through cross-linking processes. Moreover, the composites formed by dispersing nanoscale inorganic fillers in a polymer matrix can exhibit further improved polarization property. Read More

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Optimized atomic layer deposition of homogeneous, conductive AlO coatings for high-nickel NCM containing ready-to-use electrodes.

Phys Chem Chem Phys 2021 Mar 12;23(11):6725-6737. Epub 2021 Mar 12.

Center for Materials Research (LaMa), Justus Liebig University Giessen, Heinrich-Buff-Ring 16, 35392 Giessen, Germany.

Atomic layer deposition (ALD) derived ultrathin conformal AlO coating has been identified as an effective strategy for enhancing the electrochemical performance of Ni-rich LiNiCoMnO (NCM; 0 ≤x, y, z < 1) based cathode active materials (CAM) in Li-ion batteries. However, there is still a need to better understand the beneficial effect of ALD derived surface coatings on the performance of NCM based composite cathodes. In this work, we applied and optimized a low-temperature ALD derived AlO coating on a series of Ni-rich NCM-based (NCM622, NCM71. Read More

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Spin-state-dependent electrical conductivity in single-walled carbon nanotubes encapsulating spin-crossover molecules.

Nat Commun 2021 Mar 11;12(1):1578. Epub 2021 Mar 11.

IMDEA Nanociencia, Campus de Cantoblanco, Madrid, Spain.

Spin crossover (SCO) molecules are promising nanoscale magnetic switches due to their ability to modify their spin state under several stimuli. However, SCO systems face several bottlenecks when downscaling into nanoscale spintronic devices: their instability at the nanoscale, their insulating character and the lack of control when positioning nanocrystals in nanodevices. Here we show the encapsulation of robust Fe-based SCO molecules within the 1D cavities of single-walled carbon nanotubes (SWCNT). Read More

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[Martinite: an alternative to asbestos insulation available since XIX Century].

Epidemiol Prev 2020 Sep-Dec;44(5-6):402-404

Dipartimento di statistica medica, Dipartimento di medicina traslazionale, Università del Piemonte Orientale, Novara.

New findings and technical investigations carried out on the material called Martinite have found that, already at the end of the Nineteenth century, this material, with excellent insulating properties, free from asbestos and other substances harmful to human health, was available on the national and international markets. At the beginning of the Twentieth century, Martinite was used in warships of the Italian Royal Navy and, in 1950, the Italian national naval certification body (UNAV) authorized it to be used on all ships. It also had other uses, including the construction of civil power plants. Read More

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