Tuning interfacial domain walls in GdCo/Gd/GdCo′ spring magnets

Under the terms of the Creative Commons Attribution License 3.0 (CC-BY).-- et al.Spring magnets based on GdCo multilayers have been prepared to study the nucleation and evolution of interfacial domain walls (iDWs) depending on layer composition and interlayer coupling. GdCo alloy compositions in each layer were chosen so that their net magnetization aligns either with the Gd (Gd35Co65) or Co(Gd11Co89) sublattices. This condition forces an antiparallel arrangement of the layers' net magnetization and leads to nucleation of iDWs above critical magnetic fields whose values are dictated by the interplay between Zeeman and exchange energies. By combining x-ray resonant magnetic scattering with Kerr magnetometry, we provide detailed insight into the nucleation and spatial profile of the iDWs. For strong coupling (GdCo/GdCo′ bilayer), iDWs are centered at the interface but with asymmetric width depending on each layer magnetization. When interlayer coupling is weakened by introducing a thin Gd interlayer, the exchange spring effect becomes restricted to a lower temperature and field range than observed in the bilayer structure. Due to the ferromagnetic alignment between the high magnetization Gd35Co65 layer and the Gd interlayer, the iDW shrinks and moves into the lower exchange Gd interlayer, causing a reduction of iDW energy.Work supported by Spanish Ministerio de Economía y Competitividad (MINECO) under grant FIS2013-45469 and Spanish Ministerio de Ciencia e Innovacion (MICINN) under grant FIS2008-06249. Work at Argonne was supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.Peer Reviewe

Caracterización de placas de yeso con residuos de espuma de poliuretano reforzadas con fibras de polipropileno

Gypsum plasterboard that incorporates various combinations of polyurethane foam waste and polypropylene fibers in its matrix is studied. The prefabricated material was characterized in a series of standardized tests: bulk density, maximum breaking load under flexion stress, total water absorption, surface hardness, thermal properties, and reaction to fire performance. Polypropylene fibers were added to the polyurethane gypsum composites to improve the mechanical behavior of the plasterboard under loading. The results indicate that increased quantities of polymer waste led to significant reductions in the weight/surface ratio, the mechanical strength and the surface hardness of the gypsum, as well as improving its thermal resistance. The polypropylene fibers showed good adhesion to the polymer and the gypsum matrix, which enhanced the mechanical performance and the absorption capacity of these compounds. The non-combustibility test demonstrated the potential of the new material for use in internal linings.Este artículo presenta un estudio experimental basado en la reutilización de residuos de poliuretano en una matriz de yeso para elaborar una placa de yeso laminado. Las placas fueron caracterizadas mediante los ensayos normalizados de densidad aparente, carga de rotura máxima a flexión, absorción total de agua, dureza superficial y reacción al fuego. Se han introducido fibras de polipropileno en la matriz con el objetivo de aumentar la resistencia mecánica del material. Los resultados muestran que el incremento de residuo polimérico en el material implica importantes reducciones de peso, resistencia mecánica y dureza superficial, a la par que se mejora su resistencia térmica consiguiéndose valores similares a los comerciales. Las fibras de polipropileno mostraron una buena adhesión con el polímero, mejorando el comportamiento mecánico y la capacidad de absorción. El ensayo de reacción al fuego confirmó que los residuos de poliuretano pueden ser empleados en la fabricación de placas de yeso laminado en cumplimiento con la normativa

Control of magnetic domain wall motion in Co microwires by tridimensional e-beam lithographied structures

Resumen del póster presentado al 6th Spanish Workshop in Nanolithography celebrado en Zaragoza (España) del 28 al 30 de octubre de 2014.Work supported by the Spanish MICINN FIS2008-06249 and CSIC JAE Predoc grants.Peer Reviewe

Fluidised-bed incineration bottom ash as the sole precursor of alkali-activated binders: A comparison with bottom ash from grate incinerators

The novel formulation of alkali-activated binders (AABs) using incineration bottom ash (IBA) from fluidised bed (FB) combustion technology as a sole precursor was assessed. In addition, IBA-FB was compared with IBA from moving grate (IBA-MG) combustion technology. The AABs formulated with IBA-FB (AAB-FB) and IBA-MG (AAB-MG) were also evaluated from a physicochemical, mechanical, and environmental perspective. The results revealed that specific surface area in IBA-FB hinders the retention of kneading water of fresh pastes, affecting the workability, consistency, porosity, and mechanical strength of AAB-FB. Moreover, the low calcium content of IBA-FB requires that the formulated AABs must be cured at higher curing temperatures to ensure the formation of (N,C) ASH gels, while the high calcium content of IBA-MG promotes the formation of CSH gels at room temperature. The compressive strength results demonstrated that AAB-MG (≈ 11 MPa) and AAB-FB (≈ 8 MPa) could be used for non-structural purposes

Age at the time of onset of psychosis: A marker of specific needs rather than a determinant of outcome?

While there is suggestion that early onset of psychosis is a determinant of outcome; knowledge regarding correlates of later onset age is more limited. This study explores the characteristics of patients developing psychosis after age 26, towards the end of the usual age range of early intervention programs, in order to identify potential specific needs of such patients. Two hundred and fifty-six early psychosis patients aged 18-35 were followed-up prospectively over 36 months. Patients with onset after 26 ("later onset", LO) were compared to the rest of the sample. LO patients (32% of the sample) had shorter DUP, were less likely to be male, had better premorbid functioning and were more likely to have been exposed to trauma. They had greater insight at presentation and less negative symptoms overall. The trajectories for positive and depressive symptoms were similar in both groups. Evolution of functional level was similar in both groups, but while LO patients recovered faster, they were significantly less likely to return to premorbid functional level. Later psychosis onset correlates with better premorbid functioning and higher rate of trauma exposure; the latter should therefore be a treatment focus in such patients. LO patients were less likely to return to premorbid functional level, which suggests that current treatment strategies may not be efficient to help patients maintain employment. The possibility of distinct illness mechanisms according to onset age and the more central role for trauma in patients with onset after age 26 needs to be further explored

The coupling of low-level auditory dysfunction and oxidative stress in psychosis patients.

Patients diagnosed with schizophrenia often present with low-level sensory deficits. It is an open question whether there is a functional link between these deficits and the pathophysiology of the disease, e.g. oxidative stress and glutathione (GSH) metabolism dysregulation. Auditory evoked potentials (AEPs) were recorded from 21 psychosis disorder patients and 30 healthy controls performing an active, auditory oddball task. AEPs to standard sounds were analyzed within an electrical neuroimaging framework. A peripheral measure of participants' redox balance, the ratio of glutathione peroxidase and glutathione reductase activities (GPx/GR), was correlated with the AEP data. Patients displayed significantly decreased AEPs over the time window of the P50/N100 complex resulting from significantly weaker responses in the left temporo-parietal lobe. The GPx/GR ratio significantly correlated with patients' brain activity during the time window of the P50/N100 in the medial frontal lobe. We show for the first time a direct coupling between electrophysiological indices of AEPs and peripheral redox dysregulation in psychosis patients. This coupling is limited to stages of auditory processing that are impaired relative to healthy controls and suggests a link between biochemical and sensory dysfunction. The data highlight the potential of low-level sensory processing as a trait-marker of psychosis

Effect of Temperature and Humidity on the Synthesis of Alkali-Activated Binders Based on Bottom Ash from Municipal Waste Incineration

Weathered bottom ash (WBA) from municipal solid waste incineration is a calcium aluminosilicate-rich material mainly used in construction and civil engineering as a secondary aggregate. However, its use is also being considered as a precursor in the manufacture of alkali-activated binders (AA-WBA). This preliminary research aimed to deepen understanding of the potential use of WBA (>8 mm fraction) as the sole precursor of alkali-activated binders. To gain better knowledge of this material, the physicochemical, mechanical, and environmental properties of AA-WBA binders were evaluated. In addition, the effect of curing temperature (25 °C, 45 °C, 65 °C, and 85 °C) and humidity conditions (oven and climate chamber) were assessed. The results of this study revealed that temperature and humidity conditions play a fundamental role during the early formation stages of AA-WBA binders. Maximum compactness and compressive strength (29.8 MPa) were obtained in the sample cured at 65 °C in the oven and room humidity. At higher temperatures (85 °C), a substantial decrease in mechanical strength (21.2 MPa) was observed due to a lower cohesion of the binder phases. Curing in the climate chamber led to an increase in humidity, and therefore a decrease in compressive strength. Finally, lower porosity and longer curing time substantially decreased the heavy metals and metalloid leaching concentration of AA-WBA binders

Impaired fornix-hippocampus integrity is linked to peripheral glutathione peroxidase in early psychosis.

Several lines of evidence implicate the fornix-hippocampus circuit in schizophrenia. In early-phase psychosis, this circuit has not been extensively investigated and the underlying mechanisms affecting the circuit are unknown. The hippocampus and fornix are vulnerable to oxidative stress at peripuberty in a glutathione (GSH)-deficient animal model. The purposes of the current study were to assess the integrity of the fornix-hippocampus circuit in early-psychosis patients (EP), and to study its relationship with peripheral redox markers. Diffusion spectrum imaging and T1-weighted magnetic resonance imaging (MRI) were used to assess the fornix and hippocampus in 42 EP patients compared with 42 gender- and age-matched healthy controls. Generalized fractional anisotropy (gFA) and volumetric properties were used to measure fornix and hippocampal integrity, respectively. Correlation analysis was used to quantify the relationship of gFA in the fornix and hippocampal volume, with blood GSH levels and glutathione peroxidase (GPx) activity. Patients compared with controls exhibited lower gFA in the fornix as well as smaller volume in the hippocampus. In EP, but not in controls, smaller hippocampal volume was associated with high GPx activity. Disruption of the fornix-hippocampus circuit is already present in the early stages of psychosis. Higher blood GPx activity is associated with smaller hippocampal volume, which may support a role of oxidative stress in disease mechanisms

Tailoring block copolymer nanoporous thin films with acetic acid as a small guest molecule

Block copolymers offer the fabrication of mesoporous thin films with distinct nanoscale structural features. In this contribution, we present the use of acetic acid (CH3COOH) as a low‐molecular‐weight guest molecule to tune the supramolecular assembly of poly[styrene‐block‐(4‐vinylpyridine)] (PS‐b‐P4VP), offering a versatile and straightforward method to obtain tailored nanostructured films with controlled topography and pore size. Spin‐coating toluene solutions of PS‐b‐P4VP, with a variable amount of CH3COOH, leads to micellar thin films, where the micelles contain the carboxylic acid as a guest molecule. The size can be conveniently modified in these films (from 48 to 75 nm) by varying the amount of organic acid in the starting solutions. Subsequent surface reconstruction of micellar films using ethanol leads to ring‐shaped copolymer nanoporous films with modulated diameter. Controlling the micelle reconstruction process, cylindrical porous films are also obtained. Interestingly, changing the type of aliphatic carboxylic acid leads to a modification of the observed film morphology from micelles to out‐of‐plane P4VP cylinders (or lamellae) in a PS matrix