Search results for "EXPA"
showing 10 items of 820 documents
Resource or waste? A perspective of plastics degradation in soil with a focus on end-of-life options.
2018
‘Capable-of-being-shaped’ synthetic compounds are prevailing today over horn, bone, leather, wood, stone, metal, glass, or ceramic in products that were previously left to natural materials. Plastic is, in fact, economical, simple, adaptable, and waterproof. Also, it is durable and resilient to natural degradation (although microbial species capable of degrading plastics do exist). In becoming a waste, plastic accumulation adversely affects ecosystems. The majority of plastic debris pollutes waters, accumulating in oceans. And, the behaviour and the quantity of plastic, which has become waste, are rather well documented in the water, in fact. This review collects existing information on pla…
Hygro-elasto-plastic model for planar orthotropic material
2015
An in-plane elasto-plastic material model and a hygroexpansivity-shrinkage model for paper and board are introduced in this paper. The input parameters for both models are fiber orientation anisotropy and dry solids content. These two models, based on experimental results, could be used in an analytical approach to estimate, for example, plastic strain and shrinkage in simple one-dimensional cases, but for studies of the combined and more complicated effects of hygro-elasto-plastic behavior, a numerical finite element model was constructed. The finite element approach also offered possibilities for studying different structural variations of an orthotropic sheet as well as buckling behavior…
The Z boson spin observables as messengers of new physics
2017
We demonstrate that the 8 multipole parameters describing the spin state of the $Z$ boson are able to disentangle known $Z$ production mechanisms and signals from new physics at the LHC. They can be extracted from appropriate asymmetries in the angular distribution of lepton pairs from the $Z$ boson decay. The power of this analysis is illustrated by (i) the production of $Z$ boson plus jets; (ii) $Z$ boson plus missing transverse energy; (iii) $W$ and $Z$ bosons originating from the two-body decay of a heavy resonance.
Multimodal quantitative MRI assessment of cortical damage in relapsing-remitting multiple sclerosis
2016
Purpose To investigate magnetization transfer ratio (MTR), T1 relaxation time, and proton density (PD) as indicators of gray matter damage in relapsing-remitting multiple sclerosis (RRMS), reflecting different aspects of microstructural damage and as imaging correlates of clinical disability. We aimed to determine which of these parameters may optimally quantify cortical damage, and serve as an imaging surrogate of clinical disability. In this study, cortical values of MTR, a surrogate for demyelination in MS, of PD, reflecting replacement of neural tissue by water, and of T1 , indicating a complex array of microstructural changes, were assessed in a group of RRMS patients in comparison to …
mRNA COVID-19 vaccines do not increase the short-term risk of clinical relapses in multiple sclerosis
2021
Multiple sclerosis (MS) is a chronic, immune-mediated disorder of the central nervous system. A novel coronavirus, namely SARS-CoV-2, has been recently responsible for the highly infectious disease referred as COVID-19, rapidly spreading all over the world. Many vaccines have been developed to control COVID-19 pandemic, including the mRNA vaccines Pfizer/BioNTech (BNT162b2) and Moderna (mRNA1273).1 The vaccination of people with MS (pwMS) has been recommended by several national and international MS societies. However, effectiveness and safety of anti-COVID-19 mRNA vaccines in MS need to be confirmed. The aim of this study was to evaluate the short-term risk of clinical relapses in pwMS in …
The period function of reversible quadratic centers
2006
Abstract In this paper we investigate the bifurcation diagram of the period function associated to a family of reversible quadratic centers, namely the dehomogenized Loud's systems. The local bifurcation diagram of the period function at the center is fully understood using the results of Chicone and Jacobs [C. Chicone, M. Jacobs, Bifurcation of critical periods for plane vector fields, Trans. Amer. Math. Soc. 312 (1989) 433–486]. Most of the present paper deals with the local bifurcation diagram at the polycycle that bounds the period annulus of the center. The techniques that we use here are different from the ones in [C. Chicone, M. Jacobs, Bifurcation of critical periods for plane vecto…
Scaling property of variational perturbation expansion for a general anharmonic oscillator with xp-potential
1995
We prove a powerful scaling property for the extremality condition in the recently developed variational perturbation theory which converts divergent perturbation expansions into exponentially fast convergent ones. The proof is given for the energy eigenvalues of an anharmonic oscillator with an arbitrary $x^p$-potential. The scaling property greatly increases the accuracy of the results.
Pre-expanded Anterolateral Thigh Perforator Flap for Phalloplasty.
2016
The anterolateral thigh (ALT) perforator flap for phalloplasty is gaining popularity because it avoids the well-known scars of the radial forearm flap. However, scars are not eliminated, just moved to a different location, the thigh, that can for some patients be of great sexual value. Preexpansion of the ALT flap allows primary donor site closure, thus avoiding not only the unsightly appearance of a skin grafted ALT donor site, but also the skin graft donor site scar. Preoperative perforator location by means of computed tomography angiography allows safe expander placement through 2 small remote incisions.
On structural phase transitions in piperidinium halogenoantimonates(III) and bismuthates(III): X-ray, calorimetric, dilatometric, dielectric and Rama…
2000
Abstract Three piperidinium analogues: (C5H10NH2)2BiCl5, (C5H10NH2)2BiBr5 and (C5H10NH2)2SbBr5 have been studied by means of differential scanning calorimetry, thermal expansion, dielectric and Raman scattering techniques. Each piperidinium salt undergoes one high-temperature structural phase transition, which has been classified as an “order–disorder” type. All transitions are connected with onset of reorientational motion of the organic cations. The X-ray studies on (C5H10NH2)2BiCl5 show that it crystallises in orthorhombic Pna21 space group. The structure has been refined to R=0.0336. It consists of one-dimensional (BiCl52−)n polyanionic chains and two non-equivalent piperidinium cations…
Decoupling lattice and magnetic instabilities in frustrated CuMnO$_2$
2021
The $A$MnO$_{2}$ delafossites ($A$=Na, Cu), are model frustrated antiferromagnets, with triangular layers of Mn$^{3+}$~spins. At low temperatures ($T_{N}$=65 K), a $C2/m \rightarrow P\overline{1}$ transition is found in CuMnO$_2$, which breaks frustration and establishes magnetic order. In contrast to this clean transition, $A$=Na only shows short-range distortions at $T_N$. Here we report a systematic crystallographic, spectroscopic, and theoretical investigation of CuMnO$_2$. We show that, even in stoichiometric samples, non-zero anisotropic Cu displacements co-exist with magnetic order. Using X-ray/neutron diffraction and Raman scattering, we show that high pressures acts to decouple the…