Abstract: Polycrystalline samples of A(2)LaFe(2)SbO(9) (A = Ca, Sr, Ba) perovskites appeared monophasic to X-ray or neutron powder diffraction but a single-crystal study utilising transmission electron microscopy revealed a greater level of complexity. Although local charge balance is maintained, compositional and structural variations are present among and within the submicron-sized crystals. Despite the inhomogeneity, A = Ca is monophasic with a partially-ordered distribution of Fe3+ and Sb5+ cations across two crystallographically-distinct octahedral sites, i.e. Ca2La(Fe1.25Sb0.25)(2d) (Fe0.75Sb0.75)(2c)O-9. For A = Sr or Ba, the inhomogeneities result in differences in the filling patterns of the octahedra and the ordering of the B cations. Particles of A = Sr contain a phase (Fe:Sb similar to 2:1) without B cation ordering and one (Fe:Sb similar to 1:1) with B cation ordering. Monophasic A = Ba lacks long-range cation order although ordered nanodomains are present within the disordered phase. The temperature dependence of the magnetic properties of each sample is discussed.

Abstract: As decentralized electricity generation is supporting grid development into the prosumer era, this paper investigates the economic viability of adding batteries to residential microgrids powered by photovoltaic units, under various electricity pricing schemes. Batteries bring the benefits of grid-stabilization and congestion relief, and they are also becoming cheaper. The problem identified is that the main grid effectively acts as a lossless storage system, especially under the net-metering scheme, whereas using a battery involves investment costs and energy losses. This mismatch is addressed by analysing residential microgrid projects under seven tariff designs, each in seven countries of the European Union, and compare the economic viability of photovoltaic systems with and without batteries. The findings show that the conditions most favourable to batteries are given by a capacity tariff scheme allowing price arbitrage. Based on these findings, the paper discusses possibilities for further support in order to bring the economic viability of microgrids with batteries on par with that of microgrids without batteries.

Abstract: The pursuit of two-dimensional (2D) borides, MBenes, has proven to be challenging, not the least because of the lack of a suitable precursor prone to the deintercalation. Here, we studied room-temperature topochemical deintercalation of lithium from the layered polymorphs of the LiNiB compound with a considerable amount of Li stored in between [NiB] layers (33 at. % Li). Deintercalation of Li leads to novel metastable borides (Li similar to 0.5NiB) with unique crystal structures. Partial removal of Li is accomplished by exposing the parent phases to air, water, or dilute HCl under ambient conditions. Scanning transmission electron microscopy and solid-state Li-7 and B-1(1) NMR spectroscopy, combined with X-ray pair distribution function (PDF) analysis and DFT calculations, were utilized to elucidate the novel structures of (Li similar to 0.5NiB) and the mechanism of Li-deintercalation. We have shown that the deintercalation of Li proceeds via a “zip-lock” mechanism, leading to the condensation of single [NiB] layers into double or triple layers bound via covalent bonds, resulting in structural fragments with Li[NiB](2) and Li[NiB](3) compositions. The crystal structure of Li similar to 0.5NiB is best described as an intergrowth of the ordered single [NiB], double [NiB](2), or triple [NiB](3) layers alternating with single Li layers; this explains its structural complexity. The formation of double or triple [NiB] layers induces a change in the magnetic behavior from temperature-independent paramagnets in the parent LiNiB compounds to the spin-glassiness in the deintercalated Li similar to 0.5NiB counterparts. LiNiB compounds showcase the potential to access a plethora of unique materials, including 2D MBenes (NiB).

Abstract: The organic components in metal-organic frameworks (MOFs) are unique: they are embedded in a crystalline lattice, yet, as they are separated from each other by tunable free space, a large variety of dynamic behavior can emerge. These rotational dynamics of the organic linkers are especially important due to their influence over properties such as gas adsorption and kinetics of guest release. To fully exploit linker rotation, such as in the form of molecular machines, it is necessary to engineer correlated linker dynamics to achieve their cooperative functional motion. Here, we show that for MIL-53, a topology with closely spaced rotors, the phenylene functionalization allows researchers to tune the rotors' steric environment, shifting linker rotation from completely static to rapid motions at frequencies above 100 MHz. For steric interactions that start to inhibit independent rotor motion, we identify for the first time the emergence of coupled rotation modes in linker dynamics. These findings pave the way for function-specific engineering of gear-like cooperative motion in MOFs.

Abstract: Single-shot structured light profilometry (SLP) aims at reconstructing the 3D height map of an object from a single deformed fringe pattern and has long been the ultimate goal in fringe projection profilometry. Recently, deep learning was introduced into SLP setups to replace the task-specific algorithm of fringe demodulation with a dedicated neural network. Research on deep learning-based profilometry has made considerable progress in a short amount of time due to the rapid development of general neural network strategies and to the transferrable nature of deep learning techniques to a wide array of application fields. The selection of the employed loss function has received very little to no attention in the recently reported deep learning-based SLP setups. In this paper, we demonstrate the significant impact of loss function selection on height map prediction accuracy, we evaluate the performance of a range of commonly used loss functions and we propose a new mixed gradient loss function that yields a higher 3D surface reconstruction accuracy than any previously used loss functions.

Abstract: This study investigates farmers' preferences and willingness to pay for cropland attributes in Bahir Dar, north-west Ethiopia. A choice experiment is used to elicit farmers' preferences between different land use attributes, including a monetary attribute. The study was conducted in the croplands that are threatened by land expro-priation for urban expansion. A survey was undertaken with 144 farmers in four rural kebeles surrounding the city (Addis Alem, Weramit, Wereb and Zenzelima). In the survey, respondents were provided with hypothetical land purchasing decisions, with three alternatives (i.e., two hypothetical parcels and an opt-out option). A choice experiment was undertaken to measure farmers' interest in different types of croplands, which varies with respect to irrigability, number of trees per ha, soil erosion resistance and water holding capacity of the cropland. Estimation of two mixed logit models was carried out. The estimation results show that, although the farmers did not show strong preferences for each attribute of the cropland, many farmers in the area showed interest in the proposed alternative croplands. Farmers show more interest for the land that is irrigable, gentle slope and with medium water holding capacity. The results also indicate that farmers assign highest marginal willingness to pay (MWTP) (79.01 ETB per square meter) for irrigated land, followed by medium water holding capacity with MWTP of 52.13 ETB per square meter. We believe that the results of this study would help land use policy and decision makers in the study area to consider the various attributes of cropland in land use planning, including land expropriation programs, which assures the sustainability of ecosystem services.

Abstract: The first covalently linked conjugate of metal phthalocyaninate and chlorin e(6) derivative has been obtained by transesterification of alpha-ketomethyl ester in methylpheophorbide a with zinc(II) 2-(2-hydroxymethylbenzyloxy)-9(10),16(17),23(24)-tri-tert-butylphthalocyaninate under mild conditions. The dyad exhibits a panchromatic nature revealing both the phthalocyanine and pheophorbide derived bands in the UV-Vis absorption spectrum. The H-1 NMR spectroscopy data combined with theoretical calculations indicate the presence of spatial intramolecular interactions between the phthalocyanine, pheophorbide and spacer fragments of the dyad allowing to forecast its enhanced nonlinear optical properties, as well as the characteristic energy transfer from the excited pheophorbide subunit to the phthalocyanine core. Indeed, when excited in the UV-Vis range, the conjugate shows red fluorescence with the spectral maximum at 686 nm, which is close to the one of the initial zinc phthalocyaninate. Furthermore, the dyad effectively generates singlet oxygen and, in the presence of polyvinylpyrrolidone (PVP) as biocompatible solubilizer, forms stable micellar saline solutions with the particles ranged in size between 40 and 100 nm. These nanoparticles represent promising third-generation photosensitizing systems for application in theranostics.

Abstract: We study the magnetic properties of platinum diselenide (PtSe2) intercalated with Ti, V, Cr, and Mn, using first-principle density functional theory (DFT) calculations and Monte Carlo (MC) simulations. First, we present the equilibrium position of intercalants in PtSe2 obtained from the DFT calculations. Next, we present the magnetic groundstates for each of the intercalants in PtSe2 along with their critical temperature. We show that Ti intercalants result in an in-plane AFM and out-of-plane FM groundstate, whereas Mn intercalant results in in-plane FM and out-of-plane AFM. V intercalants result in an FM groundstate both in the in-plane and the out-of-plane direction, whereas Cr results in an AFM groundstate both in the in-plane and the out-of-plane direction. We find a critical temperature of <0.01 K, 111 K, 133 K, and 68 K for Ti, V, Cr, and Mn intercalants at a 7.5% intercalation, respectively. In the presence of Pt vacancies, we obtain critical temperatures of 63 K, 32 K, 221 K, and 45 K for Ti, V, Cr, and Mn-intercalated PtSe2, respectively. We show that Pt vacancies can change the magnetic groundstate as well as the critical temperature of intercalated PtSe2, suggesting that the magnetic groundstate in intercalated PtSe2 can be controlled via defect engineering.

Abstract: Electronic, optical, and thermoelectric properties of the beta-antimonene (beta-Sb) monolayer under the external biaxial strain effects are fully investigated through the first-principles calculations. The studied two-dimensional (2D) system is dynamically and structurally stable as examined via phonon spectrum and cohesive energy. At equilibrium, the beta-Sb single layer exhibits an indirect band gap of 1.310 and 1.786 eV as predicted by the PBE and HSE06 functionals, respectively. Applying external strain may induce the indirect-direct gap transition and significant variation of the energy gap. The calculated optical spectra indicate the enhancement of the optical absorption in a wide energy range from infrared to ultraviolet as induced by the applied strain. In the visible and ultraviolet regime, the absorption coefficient can reach values as large as 82.700 (10(4)/cm) and 91.458 (10(4)/cm). Results suggest that the thermoelectric performance may be improved considerably by applying proper external strain with the figure of merit reaching a value of 0.665. Our work demonstrates that the external biaxial strains may be an effective method to make the beta-Sb monolayer prospective 2D material for optoelectronic and thermoelectric applications.

Abstract: Time evolution of precipitates related to age-hardening in Ti-2.3 wt pct Cu alloys was investigated by electron microscopy. In isothermal aging at 723 K, the hardness increases continuously owing to precipitation strengthening, whereas in two-step aging where the aging temperature is switched from 673 K to 873 K after 100 hours, the hardness is found to drastically drop after the aging temperature switches. In isothermal aging, metastable and stable precipitates are independently nucleated, whereas characteristic V-shaped clusters of precipitates are observed during the two-step aging. It is revealed by atomic-scale observations that the V-shaped clusters are composed of metastable and stable precipitates and each type of precipitate has a different orientation relationship with the alpha phase: (10 (3) over bar)//(0001)(alpha) and [0 (1) over bar0]//respectively. The drop in hardness during two-step aging can be explained by a synergistic effect of decreased precipitation strengthening and solid solution strengthening. (C) The Minerals, Metals & Materials Society and ASM International 2021

Abstract: Multiplex detection of emerging pollutants is essential to improve quality control of water treatment plants, which requires portable systems capable of real-time monitoring. In this paper we describe a flexible, dual electrochemical sensing device that detects nonylphenol and paroxetine in tap water samples. The platform contains two voltammetric sensors, with different working electrodes that were either pretreated or functionalized. Each working electrode was judiciously tailored to cover the concentration range of interest for nonylphenol and paroxetine, and square wave voltammetry was used for detection. An electrochemical pretreatment with sulfuric acid on the printed electrode enabled a selective detection of nonylphenol in 1.0-10 x 10(-6) mol L-1 range with a limit of detection of 8.0 x 10(-7) mol L-1. Paroxetine was detected in the same range with a limit of detection of 6.7 x 10(-7) mol L-1 using the printed electrode coated with a layer of carbon spherical shells. Simultaneous detection of the two analytes was achieved in tap water samples within 1 min, with no fouling and no interference effects. The long-term monitoring capability of the dual sensor was demonstrated in phosphate buffer for 45 days. This performance is statistically equivalent to that of high-performance liquid chromatography (HPLC) for water analysis. The dual-sensor platform is generic and may be extended to other water pollutants and clinical biomarkers in real-time monitoring of the environment and health conditions.

Abstract: The invention of silicon drift detectors has resulted in an unprecedented improvement in detection efficiency for energy-dispersive X-ray (EDX) spectroscopy in the scanning transmission electron microscope. The result is numerous beautiful atomic-scale maps, which provide insights into the internal structure of a variety of materials. However, the task still remains to understand exactly where the X-ray signal comes from and how accurately it can be quantified. Unfortunately, when crystals are aligned with a low-order zone axis parallel to the incident beam direction, as is necessary for atomic-resolution imaging, the electron beam channels. When the beam becomes localized in this way, the relationship between the concentration of a particular element and its spectroscopic X-ray signal is generally nonlinear. Here, we discuss the combined effect of both spatial integration and sample tilt for ameliorating the effects of channeling and improving the accuracy of EDX quantification. Both simulations and experimental results will be presented for a perovskite-based oxide interface. We examine how the scattering and spreading of the electron beam can lead to erroneous interpretation of interface compositions, and what approaches can be made to improve our understanding of the underlying atomic structure.

Abstract: The properties of correlated oxides can be manipulated by forming short-period superlattices since the layer thicknesses are comparable with the typical length scales of the involved correlations and interface effects. Herein, we studied the metal-insulator transitions (MITs) in tetragonal NdNiO3/SrTiO3 superlattices by controlling the NdNiO3 layer thickness, n in the unit cell, spanning the length scale of the interfacial octahedral coupling. Scanning transmission electron microscopy reveals a crossover from a modulated octahedral superstructure at n = 8 to a uniform nontilt pattern at n = 4, accompanied by a drastically weakened insulating ground state. Upon further reducing n the predominant dimensionality effect continuously raises the MIT temperature, while leaving the antiferromagnetic transition temperature unaltered down to n = 2. Remarkably, the MIT can be enhanced by imposing a sufficiently large strain even with strongly suppressed octahedral rotations. Our results demonstrate the relevance for the control of oxide functionalities at reduced dimensions.

Abstract: We report the formation of nanobubbles on graphene with a radius of the order of 1 nm, using ultralow energy implantation of noble gas ions (He, Ne, Ar) into graphene grown on a Pt(111) surface. We show that the universal scaling of the aspect ratio, which has previously been established for larger bubbles, breaks down when the bubble radius approaches 1 nm, resulting in much larger aspect ratios. Moreover, we observe that the bubble stability and aspect ratio depend on the substrate onto which the graphene is grown (bubbles are stable for Pt but not for Cu) and trapped element. We interpret these dependencies in terms of the atomic compressibility of the noble gas as well as of the adhesion energies between graphene, the substrate, and trapped atoms.