2,663 research outputs found
Influence of chemical treatment on the recycling of composites before pyrolysis
Recycling of carbon fibers is one of the upcoming global research topics in composite engineering. This work investigates the influence of chemical treatment on the recovery of carbon fibers from carbon fiber reinforced plastic before pyrolysis. The chemical pretreatment was achieved using a zinc chloride/ethanol solution. The pyrolysis process was conducted in a sliding furnace. The effect of such pre-treatment on thermal degradation behaviour was determined by a thermogravimetric analyser (TGA). An original sample was also investigated for benchmarking. After the thermal pyrolysis process, the fiber tensile properties were measured using a single fiber tester. The surface functional groups and graphitization degree recovered carbon fiber were characterized using X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The surface morphology of recycled carbon fibers was investigated by SEM. Pristine carbon fibers were also included in the study for benchmarking. During the pyrolysis process, the devolatilisation temperature of the pre-impregnated prepregreduced by around 40-50°C and the peak temperature was 40-50°C lower compared to that of the original prepreg. The chemical pre-treatment process reduces the pyrolysis temperature compared to the conventional pyrolysis process. After pyrolysis in nitrogen with a small amount of air, loose carbon fibers were recovered, and their surface was clean. The similar surface functional groups and the decrease of degree of graphitization were detected on the recycled carbon fiber
The relationship between SNPS in the genes of TLR signal transduction pathway downstream elements and rheumatoid arthritis susceptibility
Toll-like receptors (TLRs) play an important role in the induction and regulation of the innate immune system or adaptive immune responses. Genetic variations within human TLRs have been reported to be associated with rheumatoid arthritis (RA). This study was conducted to investigate correlation between SNP of downstream mononucleotide in signal transduction of Toll-like receptors and predisposing genes of RA. There was obviously correlative between single nucleotide polymorphism and predisposing genes of RA. G-type of IL-1RAP rs766442 may be protecting genes of RA, while T-type alleles of IL-6R rs11265618 and IL-1RAP rs766442 may be susceptible genes of RA. In conclusion, the studies on the nucleis acid polymorphism in TLRs signal pathway contribute to disclose genes’ influence on the attack mechanism of RA, early diagnosis and treatment of RA.Толл-подобные рецепторы (TLRs) играют важную роль в индукции и регуляции врожденной иммунной системы или адаптивных иммунных ответах. Показано, что что генетическая изменчивость TLRs человека связана с ревматоидным артритом (РА). Целью настоящей работы было изучение корреляций между однонуклеотидным полиморфизмом в сигнальной трансдукции TLRs и генами предрасположенности к РА. G-тип IL-1RAP rs766442 могут быть генами, предохраняющими от РА, в то время как аллели T-типа IL-6R rs11265618 и IL-1RAP rs766442 могут быть генами чувствительности к РА. Изучение полиморфизма нуклеиновых кислот в сигнальном пути TLRs может внести вклад в выявление участия генов в механизмах приступов РА, раннюю диагностику и лечение РА.The study was supported by Shandong Province young scientist in incentive fund (Grant № 2006BS03018) and National Natural Science Foundation of China (Grant № 30801025)
Cognitive phenotype and differential gene expression in a hippocampal homologue in two species of frog
The complexity of an animal's interaction with its physical and/or social environment is thought to be associated with behavioral flexibility and cognitive phenotype, though we know little about this relationship in amphibians. We examined differences in cognitive phenotype in two species of frog with divergent natural histories. The greenand- black poison frog (Dendrobates auratus) is diurnal, displays enduring social interactions, and uses spatially distributed resources during parental care. Tungara frogs (Physalaemus=Engystomops pustulosus) are nocturnal, express only fleeting social interactions, and use ephemeral puddles to breed in a lek-type mating system. Comparing performance in identical discrimination tasks, we find that D. auratus made fewer errors when learning and displayed greater behavioral flexibility in reversal learning tasks than tungara frogs. Further, tungara frogs preferred to learn beacons that can be used in direct guidance whereas D. auratus preferred position cues that could be used to spatially orient relative to the goal. Behavioral flexibility and spatial cognition are associated with hippocampal function in mammals. Accordingly, we examined differential gene expression in the medial pallium, the amphibian homolog of the hippocampus. Our preliminary data indicate that genes related to learning and memory, synaptic plasticity, and neurogenesis were upregulated in D. auratus, while genes related to apoptosis were upregulated in tungara frogs, suggesting that these cellular processes could contribute to the differences in behavioral flexibility and spatial learning we observed between poison frogs and tungara frogs
A liquid helium target system for a measurement of parity violation in neutron spin rotation
A liquid helium target system was designed and built to perform a precision
measurement of the parity-violating neutron spin rotation in helium due to the
nucleon-nucleon weak interaction. The measurement employed a beam of low energy
neutrons that passed through a crossed neutron polarizer--analyzer pair with
the liquid helium target system located between them. Changes between the
target states generated differences in the beam transmission through the
polarizer--analyzer pair. The amount of parity-violating spin rotation was
determined from the measured beam transmission asymmetries. The expected
parity-violating spin rotation of order rad placed severe constraints
on the target design. In particular, isolation of the parity-odd component of
the spin rotation from a much larger background rotation caused by magnetic
fields required that a nonmagnetic cryostat and target system be supported
inside the magnetic shielding, while allowing nonmagnetic motion of liquid
helium between separated target chambers. This paper provides a detailed
description of the design, function, and performance of the liquid helium
target system.Comment: V2: 29 pages, 14 figues, submitted to Nucl. Instrum. Meth. B. Revised
to address reviewer comment
Charge and spin inhomogeneous phases in the Ferromagnetic Kondo Lattice Model
We study numerically the one-dimensional ferromagnetic Kondo lattice. This
model is widely used to describe nickel and manganese perovskites. Due to the
competition between double and super-exchange, we find a region where the
formation of magnetic polarons induces a charge-ordered state. This ordering is
present even in the absence of any inter-site Coulomb repulsion. There is an
insulating gap associated to the charge structure formation. We also study the
insulator-metal transition induced by a magnetic field which removes
simultaneously both charge and spin ordering.Comment: 7 pages, 11 figure
-- mixing and oblique corrections in an model
A global fit for experiments is included in this revised version.Comment: IFP-460-UNC, TRI-PP-93-11, 20 pages, 2 figures are appende
Quasiparticle photoemission intensity in doped two-dimensional quantum antiferromagnets
Using the self-consistent Born approximation, and the corresponding wave
function of the magnetic polaron, we calculate the quasiparticle weight
corresponding to destruction of a real electron (in contrast to creation of a
spinless holon), as a funtion of wave vector for one hole in a generalized
model and the strong coupling limit of a generalized Hubbard model. The
results are in excellent agreement with those obtained by exact diagonalization
of a sufficiently large cluster. Only the Hubbard weigth compares very well
with photoemission measurements in Sr_2CuO_2Cl_2.Comment: 11 pages, latex, 3 figure
Relation Between Chiral Susceptibility and Solutions of Gap Equation in Nambu--Jona-Lasinio Model
We study the solutions of the gap equation, the thermodynamic potential and
the chiral susceptibility in and beyond the chiral limit at finite chemical
potential in the Nambu--Jona-Lasinio (NJL) model. We give an explicit relation
between the chiral susceptibility and the thermodynamic potential in the NJL
model. We find that the chiral susceptibility is a quantity being able to
represent the furcation of the solutions of the gap equation and the
concavo-convexity of the thermodynamic potential in NJL model. It indicates
that the chiral susceptibility can identify the stable state and the
possibility of the chiral phase transition in NJL model.Comment: 21 pages, 6 figures, misprints are correcte
肥育牛の肉質と血液成分の関係について
In fattened steers of Holstein breed correlation coefficients between factors of the carcass, and between roast grade and size of selected body parts were studied. Study of correlation between roast grade and levels of serumal components of blood taken at slaughter was carried out in the steer above mentioned. Roast grade had minus significant correlation to fat cover depth and daily gain, and plus significant correlation to hips width and thurls width. Correlations between roast grade and concentration of blood serum magnesium or cholesterol were shown, but not significant. There were significant minus correlations between roast grade and concentrations of TP, Al, Gl, Ca, Ca/Mg in the serum. Ratio of Mg/ (Ca+P+Mg) had a significant positive correlation to roast grade. When grouped by sire, steers group with low daily gain had generally a high quality of roast
Bonding in MgSi and AlMgSi Compounds Relevant to AlMgSi Alloys
The bonding and stability of MgSi and AlMgSi compounds relevant to AlMgSi
alloys is investigated with the use of (L)APW+(lo) DFT calculations. We show
that the and phases found in the precipitation sequence are
characterised by the presence of covalent bonds between Si-Si nearest neighbour
pairs and covalent/ionic bonds between Mg-Si nearest neighbour pairs. We then
investigate the stability of two recently discovered precipitate phases, U1 and
U2, both containing Al in addition to Mg and Si. We show that both phases are
characterised by tightly bound Al-Si networks, made possible by a transfer of
charge from the Mg atoms.Comment: 11 pages, 30 figures, submitted to Phys. Rev.
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