Multiferroic (Nd,Fe)-doped PbTiO3 ceramics with coexistent ferroelectricity and magnetism at room temperature

We report the structural, dielectric, elastic, ferroelectric and ferromagnetic properties of multiferroic (Nd, Fe)-doped PbTiO3 perovskite ceramics with composition (Pb 0.88 Nd 0.08 )(Ti 0.94 Fe 0.04 Mn 0.02 )O 3 , prepared by different solid state reaction methods: the first one based on a single-stage calcination (Method I) and the second based on a double-stage calcination (Method II). Structural, dielectric and anelastic measurements evidenced a double phase transition for samples prepared by Method I, which has been attributed to phase separation. This phase separation has been confirmed also by TEM and HRTEM investigations. Samples prepared by Method II showed a single phase transition from paraelectric to ferroelectric phase. We found coexistent ferroelectric and ferromagnetic properties, also at room-temperature, but only for ceramics prepared by Method II. The crucial role of calcination process for avoiding phase separation and obtaining homogeneous structures with ferroelectric and ferromagnetic order is underlined

Hydrogen bonding in Alzheimer's amyloid-β fibrils probed by 15N{17O} REAPDOR solid-state NMR spectroscopy

An exclusive label: 15N{17O} REAPDOR NMR was used to validate intermolecular C17O=H-15N hydrogen bonding in Ac-Aβ(16-22)-NH2 (see scheme) and Aβ(11-25) amyloid fibrils, which are associated with Alzheimer's disease, by selectively labeling them with 17O and 15N. This method was effective for confirming the structure of these fibrils, and could be useful for a number of other biological samples. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

High Molecular Weight Mixed-Linkage Glucan as a Mechanical and Hydration Modulator of Bacterial Cellulose:Characterization by Advanced NMR Spectroscopy

Bacterial cellulose (BC) consists of a complex three-dimensional organization of ultrafine fibers which provide unique material properties such as softness, biocompatibility, and water-retention ability, of key importance for biomedical applications. However, there is a poor understanding of the molecular features modulating the macroscopic properties of BC gels. We have examined chemically pure BC hydrogels and composites with arabinoxylan (BC-AX), xyloglucan (BC-XG), and high molecular weight mixed-linkage glucan (BC-MLG). Atomic force microscopy showed that MLG greatly reduced the mechanical stiffness of BC gels, while XG and AX did not exert a significant effect. A combination of advanced solid-state NMR methods allowed us to characterize the structure of BC ribbons at ultra-high resolution and to monitor local mobility and water interactions. This has enabled us to unravel the effect of AX, XG, and MLG on the short-range order, mobility, and hydration of BC fibers. Results show that BC-XG hydrogels present BC fibrils of increased surface area, which allows BC-XG gels to hold higher amounts of bound water. We report for the first time that the presence of high molecular weight MLG reduces the density of clusters of BC fibrils and dramatically increases water interactions with BC. Our data supports two key molecular features determining the reduced stiffness of BC-MLG hydrogels, that is, (i) the adsorption of MLG on the surface of BC fibrils precluding the formation of a dense network and (ii) the preorganization of bound water by MLG. Hence, we have produced and fully characterized BC-MLG hydrogels with novel properties which could be potentially employed as renewable materials for applications requiring high water retention capacity (e.g. personal hygiene products)

CONSIDERATIONS ON ENERGETIC CROPS POTENTIAL

In order to breathe fresh and clean air, nature and terrestrial atmosphere should be preserved and protected. Carbon emissions represent one of the main enemies of air quality. Recently, carbon emissions have surpassed all the predictions because the excessive industrialization, becoming the determining factor for global warming. A viable alternative to carbon emissions reduction is the utilization of energy sources that can diminish the noxious substances emissions up to zero. This can be done by using the power of wind, sun, water, energy plants, etc. Among the energetic potential plants, the biomass is obtained- a form of renewable energy which final product is biofuel

Incorporating psychology into cyber security education: A pedagogical approach

The role of the human in cyber security is well acknowledged. Many cyber security incidents rely upon targets performing specific behavioural actions, such as opening a link within a phishing email. Cyber adversaries themselves are driven by psychological processes such as motivation, group dynamics and social identity. Furthermore, both intentional and unintentional insider threats are associated with a range of psychological factors, including cognitive load, mental wellbeing, trust and interpersonal relations. By incorporating psychology into cyber security education, practitioners will be better equipped with the skills they need to address cyber security issues. However, there are challenges in doing so. Psychology is a broad discipline, and many theories, approaches and methods may have little practical significance to cyber security. There is a need to sift through the literature to identify what can be applied to cyber security. There are also pedagogical differences in how psychology and cyber security are taught and also psychological differences in the types of student that may typically study psychology and cyber security. To engage with cyber security students, it is important that these differences are identified and positively addressed. Essential to this endeavor is the need to discuss and collaborate across the two disciplines. In this paper, we explore these issues and discuss our experiences as psychology and cyber security academics who work across disciplines to deliver psychology education to cyber security students, practitioners and commercial clients

Toward a structural model for the aluminum tellurite glass system

Neutron diffraction, 27Al MAS NMR, and 27Al Double Quantum MAS NMR results are presented and analyzed to determine the local environments of the cations in a series of aluminum tellurite glasses. Total scattering results show that, within a maximum Te–O distance of 2.36 Å, tellurium exhibits a mix of [TeO3E] and [TeO4E] environments (E = electron lone-pair), with a linear reduction in the average tellurium–oxygen coordination number as Al2O3 is added to the glass. This is accompanied by a linear decrease in the average aluminum–oxygen coordination number as [AlO4] units form at the expense of [AlO6] units, while the fraction of [AlO5] units remains roughly constant. A consideration of the bonding requirements of the five structural units in the glass, [TeO3E], [TeO4E], [AlO4], [AlO5], and [AlO6], has allowed a direct quantitative relationship between tellurium–oxygen and aluminum–oxygen coordination numbers to be derived for the first time, and this has been successfully extended to the boron tellurite system. Double Quantum 27Al MAS NMR indicates that, in contrast to previous reports, the shortest Al...Al separations are significantly smaller (∼3.2 Å) than expected for a uniform distribution and there is a preference for [AlO6]–[AlO6] and [AlO4]–[AlO4] corner sharing polyhedra. These associations support a new structural model which successfully applies the principle of charge balance to describe the interaction of tellurium and aluminum and identifies and explains the clustering of [AlOn] polyhedra in the glass and their preferred associations. [AlO6] and [TeO4E] units dominate the network in TeO2-rich glasses and [AlO4]− units form to stabilize the [TeO3E]+ units as alumina is added to the glass

EQUIPMENT FOR EXTRACTING AND PLANTING EARTH BALE ROOT PLANTS

Trees are one of the biggest  organisms living on the planet and their role is extremely important, namely that to maintain the purity of air we breathe, improve water quality, prevent soil erosion, reduce noise level, ensure food, construction materials and eventually people comfort. Plantation and transplantation of trees by means of specialized equipment  in comparison with human force leads to an increased planting speed and higher yield, economically speaking. This paper is designed to present different constructive variants, at world level, of equipment for extracting and planting trees with earth bale at their roots, necessary for afforestation, landscape design, tree nurseries

Identifying the components of the solid–electrolyte interphase in Li-ion batteries

The importance of the solid–electrolyte interphase (SEI) for reversible operation of Li-ion batteries has been well established, but the understanding of its chemistry remains incomplete. The current consensus on the identity of the major organic SEI component is that it consists of lithium ethylene di-carbonate (LEDC), which is thought to have high Li-ion conductivity, but low electronic conductivity (to protect the Li/C electrode). Here, we report on the synthesis and structural and spectroscopic characterizations of authentic LEDC and lithium ethylene mono-carbonate (LEMC). Direct comparisons of the SEI grown on graphite anodes suggest that LEMC, instead of LEDC, is likely to be the major SEI component. Single-crystal X-ray diffraction studies on LEMC and lithium methyl carbonate (LMC) reveal unusual layered structures and Li+ coordination environments. LEMC has Li+ conductivities of >1 × 10−6 S cm−1, while LEDC is almost an ionic insulator. The complex interconversions and equilibria of LMC, LEMC and LEDC in dimethyl sulfoxide solutions are also investigated

Ectopic callose deposition into woody biomass modulates the nano-architecture of macrofibrils

Plant biomass plays an increasingly important role in the circular bioeconomy, replacing non-renewable fossil resources. Genetic engineering of this lignocellulosic biomass could benefit biorefinery transformation chains by lowering economic and technological barriers to industrial processing. However, previous efforts have mostly targeted the major constituents of woody biomass: cellulose, hemicellulose and lignin. Here we report the engineering of wood structure through the introduction of callose, a polysaccharide novel to most secondary cell walls. Our multiscale analysis of genetically engineered poplar trees shows that callose deposition modulates cell wall porosity, water and lignin contents and increases the lignin–cellulose distance, ultimately resulting in substantially decreased biomass recalcitrance. We provide a model of the wood cell wall nano-architecture engineered to accommodate the hydrated callose inclusions. Ectopic polymer introduction into biomass manifests in new physico-chemical properties and offers new avenues when considering lignocellulose engineering