1,967 research outputs found
Towards highly homogeneous self-regulating heating of smart nanocomposites
Smart self-regulating heating devices utilising the positive temperature coefficient (PTC) effect have shown great potential in advancing applications across healthcare, soft robotics, and energy-efficient manufacturing. However, achieving homogeneous resistive heating within such temperature self-controllable nanocomposites remains a significant challenge, falling short of meeting the requirements of advanced heating systems. This study explores and evaluates multiple innovative strategies aimed at enhancing the temperature uniformity of PTC nanocomposites. By identifying and analysing the primary physical mechanisms behind the inhomogeneous heating observed in conductive polymer composites, we propose a series of targeted strategies, ranging from customised material formulations to novel electrode configurations. Recycled carbon fibres have also been explored and upcycled as an effective solution for homogenous self-regulating heating. Through a comprehensive analysis of experimental results, the effectiveness of each strategy has been evaluated with a significantly improved temperature uniformity (from 32.6 to 2.7 % variation at 125 °C), providing valuable insights for the design and development of advanced self-regulating heating devices based on conductive polymer nanocomposites, while offering promising prospects for achieving more energy-efficient and uniform heating in various industrial applications
Physiological models of body composition and human obesity
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Entanglement in nuclear quadrupole resonance
Entangled quantum states are an important element of quantum information
techniques. We determine the requirements for states of quadrupolar nuclei with
spins >1/2 to be entangled. It was shown that entanglement is achieved at low
temperature by applying a magnetic field to a quadrupolar nuclei possess
quadrupole moments, which interacts with the electricfield gradient produced by
the charge distribution in their surroundings.Comment: 9 pages, 5 figure
Light dark matter in the NMSSM: upper bounds on direct detection cross sections
In the Next-to-Minimal Supersymmetric Standard Model, a bino-like LSP can be
as light as a few GeV and satisfy WMAP constraints on the dark matter relic
density in the presence of a light CP-odd Higgs scalar. We study upper bounds
on the direct detection cross sections for such a light LSP in the mass range
2-20 GeV in the NMSSM, respecting all constraints from B-physics and LEP. The
OPAL constraints on e^+ e^- -> \chi^0_1 \chi^0_i (i > 1) play an important role
and are discussed in some detail. The resulting upper bounds on the
spin-independent and spin-dependent nucleon cross sections are ~ 10^{-42}
cm^{-2} and ~ 4\times 10^{-40} cm^{-2}, respectively. Hence the upper bound on
the spin-independent cross section is below the DAMA and CoGeNT regions, but
could be compatible with the two events observed by CDMS-II.Comment: 17 pages, 3 figure
Cooling of Dark-Matter Admixed Neutron Stars with density-dependent Equation of State
We propose a dark-matter (DM) admixed density-dependent equation of state
where the fermionic DM interacts with the nucleons via Higgs portal. Presence
of DM can hardly influence the particle distribution inside neutron star (NS)
but can significantly affect the structure as well as equation of state (EOS)
of NS. Introduction of DM inside NS softens the equation of state. We explored
the effect of variation of DM mass and DM Fermi momentum on the NS EOS.
Moreover, DM-Higgs coupling is constrained using dark matter direct detection
experiments. Then, we studied cooling of normal NSs using APR and DD2 EOSs and
DM admixed NSs using dark-matter modified DD2 with varying DM mass and Fermi
momentum. We have done our analysis by considering different NS masses. Also DM
mass and DM Fermi momentum are varied for fixed NS mass and DM-Higgs coupling.
We calculated the variations of luminosity and temperature of NS with time for
all EOSs considered in our work and then compared our calculations with the
observed astronomical cooling data of pulsars namely Cas A, RX J0822-43, 1E
1207-52, RX J0002+62, XMMU J17328, PSR B1706-44, Vela, PSR B2334+61, PSR
B0656+14, Geminga, PSR B1055-52 and RX J0720.4-3125. It is found that APR EOS
agrees well with the pulsar data for lighter and medium mass NSs but cooling is
very fast for heavier NS. For DM admixed DD2 EOS, it is found that for all
considered NS masses, all chosen DM masses and Fermi momenta agree well with
the observational data of PSR B0656+14, Geminga, Vela, PSR B1706-44 and PSR
B2334+61. Cooling becomes faster as compared to normal NSs in case of
increasing DM mass and Fermi momenta. It is infered from the calculations that
if low mass super cold NSs are observed in future that may support the fact
that heavier WIMP can be present inside neutron stars.Comment: 24 Pages, 15 Figures and 2 Tables. Version accepted in The European
Physical Journal
Recommended from our members
The nature of ferromagnetism in the chiral helimagnet Cr1/3NbS2
The chiral helimagnet Cr1/3NbS2 hosts exotic spin textures, whose influence on the magneto-transport properties make this material an ideal candidate for future spintronic applications. To date, the interplay between macroscopic magnetic and transport degrees of freedom is believed to result from a reduction in carrier scattering following spin order. Here, we present electronic structure measurements across the helimagnetic transition temperature TC that challenges this view. We show that the Fermi surface is comprised of strongly hybridized Nb- and Cr-derived electronic states, and that spectral weight close to the Fermi level increases anomalously as the temperature is lowered below TC. These findings are rationalized on the basis of first principle density functional theory calculations, which reveal a large nearest-neighbor exchange energy, suggesting the interaction between local spin moments and hybridized Nb- and Cr-derived itinerant states to go beyond the perturbative interaction of Ruderman-Kittel-Kasuya-Yosida, suggesting instead a mechanism rooted in a Hund’s exchange interaction
Chern-Simons black holes: scalar perturbations, mass and area spectrum and greybody factors
We study the Chern-Simons black holes in d-dimensions and we calculate
analytically the quasi-normal modes of the scalar perturbations and we show
that they depend on the highest power of curvature present in the Chern-Simons
theory. We obtain the mass and area spectrum of these black holes and we show
that they have a strong dependence on the topology of the transverse space and
they are not evenly spaced. We also calculate analytically the reflection and
transmission coefficients and the absorption cross section and we show that at
low frequency limit there is a range of modes which contributes to the
absorption cross section.Comment: 19 pages, 18 figures, the title has been changed to reflect the
addition of an another section on the reflection, transmission coefficients
and absorption cross sections of the Chern-Simons black holes. Version to be
published in JHE
Appendectomy and diagnosis-related groups (DRGs): patient classification and hospital reimbursement in 11 European countries
Cardioprotective Effect of Nicorandil, a Mitochondrial ATP-Sensitive Potassium Channel Opener, Prolongs Survival in HSPB5 R120G Transgenic Mice
BACKGROUND: Transgenic (TG) mice with overexpression of an arg120gly (R120G) missense mutation in HSPB5 display desmin-related cardiomyopathy, which is characterized by formation of aggresomes. It is also known that progressive mitochondrial abnormalities and apoptotic cell death occur in the hearts of R120G TG mice. The role of mitochondrial dysfunction and apoptosis in disease progression, however, remains uncertain. METHODS AND RESULTS: Mitochondrial abnormalities and apoptotic cell death induced by overexpression of HSPB5 R120G were analyzed in neonatal rat cardiomyocytes. Overexpression of mutant HSPB5 led to development of aggresomes with a concomitant reduction in cell viability in the myocytes. Overexpression of mutant HSPB5 induced a reduction in the cytochrome c level in the mitochondrial fraction and a corresponding increase in the cytoplasmic fraction in the myocytes. Down-regulation of BCL2 and up-regulation of BAX were detected in the myocytes expressing the mutant HSPB5. Concomitant with mitochondrial abnormality, the activation of caspase-3 and increased apoptotic cell death was observed. Cell viability was dose-dependently recovered in myocytes overexpressing HSPB5 R120G by treatment with nicorandil a mitochondrial ATP-sensitive potassium channel opener. Nicorandil treatment also inhibited the increase in BAX, the decrease in BCL2, activation of caspase-3 and apoptotic cell death by mutant HSPB5. To confirm the results of the in-vitro study, we analyzed the effect of nicorandil in HSPB5 R120G TG mice. Nicorandil treatment appeared to reduce mitochondrial impairment and apoptotic cell death and prolonged survival in HSPB5 R120G TG mice. CONCLUSIONS: Nicorandil may prolong survival in HSPB5 R120G TG mice by protecting against mitochondrial impairments
- …