In this paper we present an analysis to simulate heating within an isolated carbon nanotube (CNT) attached to an etched tungsten tip during field emission of an electron beam. The length, radius, wall thickness and shape of the tip (closed with a hemispherical shape or open and flat) of the CNT and its separation distance from the flat surface are considered as variables. Using a finite element method, we predict the field enhancement, emission current and temperature of the CNT as a function of these parameters. The electrostatic and transient thermal analyses are integrated with the field-emission models based on the Fowler-Nordheim approximation and heating/cooling due to emitting energetic electrons (the Nottingham effect). These simulations suggest that the main mechanism responsible for heating of the CNT is Joule heating, which is significantly larger than the Nottingham effect. Results also indicate that the electrostatic characteristics of CNTs are very sensitive to the considered parameters whereas the transient thermal response is only a function of the CNT radius and wall thickness. Further, the thermal response of the CNT is independent of its geometry, meaning that, as long as a given set of geometrical conditions are present that result in a given emission current, the maximum temperature a CNT attains will be the same.
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http://dx.doi.org/10.1088/0957-4484/19/7/075702 | DOI Listing |
Inorg Chem
January 2025
Department of Chemistry & CICECO-Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal.
The development of photoresponsive ferroelastics, which couple light-induced macroscopic mechanical and microscopic domain properties, represents a frontier in materials science with profound implications for advanced functional applications. In this study, we report the rational design and synthesis of two new organic-inorganic hybrid ferroelastic crystals, (MA)(MeN)[Fe(CN)(NO)] (MA = methylammonium) () and (MA)(MeNOH)[Fe(CN)(NO)] (), using a dual-organic molecular design strategy that exploits hydrogen-bonding interactions for tailoring ferroelastic properties. Specifically, exhibits a two-step phase transition at 138 and 242 K, while the introduction of a hydroxyl group in stabilizes its ferroelastic phase to a significantly higher temperature, achieving a phase transition at 328 K, 86 K above that of .
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, National & Local Joint Engineering Research Center of Processing Technology for Aquatic Products, Jimei University, Xiamen, Fujian 361021, China.
, a crustacean of substantial importance, is a frequent trigger of food allergies. This study examined the molecular and immunological properties of troponin C from (Scy p TnC) as an allergen. The findings indicated that thermal stability of Scy p TnC comprised 150 amino acids and facilitated the induction of CD63/CD203c in basophils from crab allergy patients.
View Article and Find Full Text PDFNanoscale Horiz
January 2025
London Centre for Nanotechnology, 19 Gordon St, London, WC1H 0AH, UK.
We demonstrate low energy, forming and compliance-free operation of a resistive memory obtained by the partial oxidation of a two-dimensional layered van-der-Waals semiconductor: hafnium disulfide (HfS). Semiconductor-oxide heterostructures are achieved by low temperature (<300 °C) thermal oxidation of HfS under dry conditions, carefully controlling process parameters. The resulting HfOS/HfS heterostructures are integrated between metal contacts, forming vertical crossbar devices.
View Article and Find Full Text PDFHeliyon
January 2025
Department of Mathematics, Bangabandhu Sheikh Mujibur Rahman Science and Technology University, Gopalganj, 8100, Bangladesh.
The numerical analysis examines the attributes of magnetohydrodynamic natural convection in a closed cavity including a circular hollow. Because mono and hybrid nanofluids have many applications in thermal engineering and manufacturing, hybrid nanofluids are utilized as the substance within the entire domain. The investigation centers on a closed, trapezoidal-shaped hollow with a heated surface ring.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
DICP: Chinese Academy of Sciences Dalian Institute of Chemical Physics, State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, CHINA.
Broad-temperature optical thermometry necessitates materials with exceptional sensitivity and stability across varied thermal conditions, presenting challenges for conventional systems. Here, we report a lead-free, vacancy-ordered perovskite Cs2TeCl6, that achieves precise temperature sensing through a novel combination of self-trapped excitons (STEs) photoluminescence (PL) lifetime modulation and unprecedented fifth-order phonon anharmonicity. The STEs PL lifetime demonstrates a highly temperature-sensitive response from 200 to 300 K, ideal for low-to-intermediate thermal sensing.
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