scholarly journals In Situ Spinel Formation in a Smart Nano-Structured Matrix for No-Cement Refractory Castables

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1403 ◽  
Author(s):  
Dominika Madej ◽  
Karina Tyrała
Keyword(s):  
High Performance ◽  
Interlayer Spacing ◽  
Water Molecules ◽  
Coordination Polyhedra ◽  
Structured Matrix ◽  
Oxygen Coordination ◽  
Refractory Castables ◽  
Ceramic Bond ◽  
Spinel Mgal2o4

The hydration of an equimolar mixture of MgO and Al2O3 nano-powders has been proven to be an effective way to synthesize Mg6Al2CO3(OH)16∙4H2O as a component of a nano-structured matrix and magnesia-alumina spinel precursor for high-performance cement-free corundum-spinel refractory castables. (Mg3)–OH–brucite sites (417 °C) formed initially within the magnesia–alumina hydrating blended paste were replaced with (Mg2Al)–OH and (Mg3)–OH hydrotalcite sites, which were dehydroxylated at 420 °C and 322 °C, respectively. This reorganization was connected with the incorporation of anions and water molecules in the interlayer spacing of hydrotalcite, which was dehydrated at 234 °C. Hence, the thermal decomposition of a nano-structured matrix system containing mainly Mg6Al2CO3(OH)16∙4H2O consists of a complex sequence of dehydration, dehydroxylation and decarbonization, and this finally leads to the formation of inverse spinel MgAl2O4 and periclase MgO through many intermediate stages containing the mixed tetrahedral-octahedral Al phase and MgO-like structure. Hence, the hydraulic bond that primarily existed was replaced by a ceramic bond at a relatively low temperature, i.e., 700 °C, where a spinel was formed. Important changes in oxygen coordination polyhedra around Al3+ in the dehydrated-dehydroxylated hydrotalcite occurred between 600 and 1100 °C.

Ulm-12 and Ulm-19: The Hydrated and Anhydrous Forms of the First Synthetic Oxyfluorinated Iron Phosphate with an Open Structure

1996 ◽  
Vol 431 ◽  
Author(s):  
Myriam Cavellec ◽  
Didier Riou ◽  
Jean Marc Grenèche ◽  
Gérard Férey
Keyword(s):  
Single Crystals ◽  
Iron Phosphate ◽  
Mössbauer Spectrometry ◽  
Trigonal Bipyramid ◽  
Water Molecules ◽  
Coordination Polyhedra ◽  
Open Structure ◽  
Mossbauer Spectrometry

AbstractULM-19 or [Fe4(PO4)4F2], [C6H14N2], was obtained in a monocrystalline form from the dehydration of single crystals of ULM-12, or [Fe4(PO4)4F2(H2O)3], [C6H14N2] at 260°C. It is monoclinic (S.G. P21/n) with a = 10.009(7), b = 12.235(8), c = 17.28(2) Å, β = 106.04(5)°, V = 2034(3) Å3, Z = 4. Its structure, which can be described from the corner sharing of hexameric Fe3P3 and dimeric FeP units, directly derives from that of ULM- 12 by the loss, on three of the four Fe(III) polyhedral sites of the structure of ULM-12, of the terminal water molecules. This induces drastic changes in the coordination polyhedra of Fe(III): three octahedra and one square pyramid in ULM-12, and one octahedron, one square pyramid, one trigonal bipyramid and one tetrahedron in ULM-19. These evolutions were confirmed and characterized by in situ Mössbauer spectrometry measurements using a cryofurnace. The loss of water opens 6-ring channels beside the 12-ring tunnels already existing in ULM-12.

High performance Nanogold™-in situ hybridzation and its use in the detection of hybridized and PCR-amplified microscopical preparations

1996 ◽  
Vol 54 ◽  
pp. 896-897
Author(s):  
G. W. Hacker ◽  
I. Zehbe ◽  
J. Hainfeld ◽  
A.-H. Graf ◽  
C. Hauser-Kronberger ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Messenger Rna ◽  
High Performance ◽  
Detection System ◽  
Direct Methods ◽  
Genetic Alterations ◽  
Chain Reaction ◽  
Protein Encoding ◽  
Polymerase Chain

In situ hybridization (ISH) with biotin-labeled probes is increasingly used in histology, histopathology and molecular biology, to detect genetic nucleic acid sequences of interest, such as viruses, genetic alterations and peptide-/protein-encoding messenger RNA (mRNA). In situ polymerase chain reaction (PCR) (PCR in situ hybridization = PISH) and the new in situ self-sustained sequence replication-based amplification (3SR) method even allow the detection of single copies of DNA or RNA in cytological and histological material. However, there is a number of considerable problems with the in situ PCR methods available today: False positives due to mis-priming of DNA breakdown products contained in several types of cells causing non-specific incorporation of label in direct methods, and re-diffusion artefacts of amplicons into previously negative cells have been observed. To avoid these problems, super-sensitive ISH procedures can be used, and it is well known that the sensitivity and outcome of these methods partially depend on the detection system used.

scholarly journals In Situ Thermal-Stage Fitted-STEM Characterization of Spherical-Shaped Co/MoS2 Nanoparticles for Conversion of Heavy Crude Oils

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1239
Author(s):  
Manuel Ramos ◽  
Félix Galindo-Hernández ◽  
Brenda Torres ◽  
José Manuel Domínguez-Esquivel ◽  
Martin Heilmaier
Keyword(s):  
Molybdenum Disulfide ◽  
Sodium Molybdate ◽  
Interlayer Spacing ◽  
Scanning Transmission Electron Microscope ◽  
Interplanar Distance ◽  
Scanning Transmission ◽  
Heavy Crude ◽  
C 50 ◽  
Nano Catalysts

We report the thermal stability of spherically shaped cobalt-promoted molybdenum disulfide (Co/MoS2) nano-catalysts from in-situ heating under electron irradiation in the scanning transmission electron microscope (STEM) from room temperature to 550 °C ± 50 °C with aid of Fusion® holder (Protochip©, Inc.). The catalytic nanoparticles were synthesized via a hydrothermal method using sodium molybdate (Na2MoO4·2H2O) with thioacetamide (CH3CSNH2) and cobalt chloride (CoCl2) as promoter agent. The results indicate that the layered molybdenum disulfide structure with interplanar distance of ~0.62 nm remains stable even at temperatures of 550 °C, as observed in STEM mode. Subsequently, the samples were subjected to catalytic tests in a Robinson Mahoney Reactor using 30 g of Heavy Crude Oil (AGT-72) from the golden lane (Mexico’s east coast) at 50 atm using (ultrahigh purity) UHP hydrogen under 1000 rpm stirring at 350 °C for 8 h. It was found that there is no damage on the laminar stacking of Co/MoS2 with temperature, with interlayer spacing remaining at 0.62 nm; these sulfided catalytic materials led to aromatics rise of 22.65% and diminution of asphaltenes and resins by 15.87 and 3.53%, respectively.

Alkoxide hydrolysis in-situ constructing robust trimanganese tetraoxide/graphene composite for high-performance lithium storage

2021 ◽  
Vol 594 ◽  
pp. 531-539
Author(s):  
Liang Wu ◽  
Shaozhuan Huang ◽  
Wenda Dong ◽  
Yan Li ◽  
Zhouhao Wang ◽  
...  
Keyword(s):  
High Performance ◽  
Lithium Storage ◽  
Graphene Composite

In Situ Assembly of Ordered Hierarchical CuO Microhemisphere Nanowire Arrays for High‐Performance Bifunctional Sensing Applications

Small Methods ◽  
2021 ◽  
pp. 2100202
Author(s):  
Tiantian Dai ◽  
Zanhong Deng ◽  
Xiaodong Fang ◽  
Huadong Lu ◽  
Yong He ◽  
...  
Keyword(s):  
High Performance ◽  
Nanowire Arrays ◽  
Sensing Applications

scholarly journals A thin, deformable, high-performance supercapacitor implant that can be biodegraded and bioabsorbed within an animal body

2021 ◽  
Vol 7 (2) ◽  
pp. eabe3097
Author(s):  
Hongwei Sheng ◽  
Jingjing Zhou ◽  
Bo Li ◽  
Yuhang He ◽  
Xuetao Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Electronic Devices ◽  
Form Factors ◽  
Time Frame ◽  
Water Soluble ◽  
Two Dimensional ◽  
Medical Electronics ◽  
Thin Structure ◽  
Shed Light

It has been an outstanding challenge to achieve implantable energy modules that are mechanically soft (compatible with soft organs and tissues), have compact form factors, and are biodegradable (present for a desired time frame to power biodegradable, implantable medical electronics). Here, we present a fully biodegradable and bioabsorbable high-performance supercapacitor implant, which is lightweight and has a thin structure, mechanical flexibility, tunable degradation duration, and biocompatibility. The supercapacitor with a high areal capacitance (112.5 mF cm−2 at 1 mA cm−2) and energy density (15.64 μWh cm−2) uses two-dimensional, amorphous molybdenum oxide (MoOx) flakes as electrodes, which are grown in situ on water-soluble Mo foil using a green electrochemical strategy. Biodegradation behaviors and biocompatibility of the associated materials and the supercapacitor implant are systematically studied. Demonstrations of a supercapacitor implant that powers several electronic devices and that is completely degraded after implantation and absorbed in rat body shed light on its potential uses.

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