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Bimetallic colloidal CoPt nanoalloys with low platinum content were successfully synthesized following a modified polyol approach. Powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM) studies were performed to estimate the crystal structure, morphology, and surface functionalization of the colloids, respectively, while the room-temperature magnetic properties were measured using a vibrating sample magnetometer (VSM). The particles exhibit excellent uniformity, with a narrow size distribution, and display strong room-temperature hysteretic ferromagnetic behavior even in the as-made form. Upon annealing at elevated temperatures, progressive formation and co-existence of exchange coupled, of both chemically ordered and disordered phases significantly enhanced the room-temperature coercivity. [ABSTRACT FROM AUTHOR]

The article reveals for the first time the features of nanoparticle morphology, phase compositions, and their changes when heating FePt and CoPt nanoalloys. Nanoparticles were obtained by co-reduction of precursor solution mixtures with hydrazine hydrate. The features were found by a complex of methods of X-ray diffraction (in situ XRD and X-ray scattering), TEM HR, and cyclic voltammetry. In addition, adsorbometry results were obtained, and the stability of different nanocluster structures was calculated by the molecular dynamics method. There were only FCC solid solutions in the X-ray patterns of the FePt and CoPt nanoalloys. According to XRD, in the case of nanoparticle synthesis with Fe and Co content less than 10 at. %, the composition of solid solutions was close to or practically equal to the composition of the as-synthesized nanoparticles quantified by inductively coupled plasma optical emission spectrometry. For systems synthesis with Fe and Co content greater than the above, the solubility limits (SLs) of Fe and Co in Pt were set 11.4 ± 0.7 at. % and 17.5 ± 0.6 at. %, respectively. Therefore, there were non-registered XRD extra-phases (XRNDPh-1) in the systems when CFe,Co ≥ SL. This statement was supported by the results of TEM HR and X-ray scattering: the smallest nanocrystals (1–2 nm) and amorphous particles were found, which qualitatively agreed with the sorbometry and SAXS results. Molecular dynamics calculations of stability for FePt and CoPt alloys claimed the structures of the most stable phase corresponded to phase diagrams (A1 and L12). Specific peculiarities of the morphology and compositions of the solid solutions of nanoalloys were established: structural blockiness (domain) and composition heterogeneity, namely, platinum enrichment of internal (deep) layers and homogenization of the nanoalloy compositions at relatively low temperatures (130–200 °C). The suggested model of the formation of nanoalloys during the synthesis, qualitatively, was compliant with the results of electrochemical deposition of FePt films on the surface of various electrodes. When nanocrystals of solid solutions (C(Fe, Co) < SL) were heated above specific temperatures, there were phase transformations with the formation of two-phase regions, with solid solutions enriched with platinum or iron (non-registered XRD phase XRNDPh-2). The newly formed phase was most likely intermetallic compounds, FePt3, CoPt3. As a result of the study, the model was developed, taking into account the nanoscale of the particles: XRDPh (A1, FeaPt1−a) → XRDPh (A1, Fem×a−xPtm−m×a+x) + XRNDPh-2 (Fen×a+yPtn−n×a−y) (here, m + n = 1, m ≤ 1, n ≤ 1). [ABSTRACT FROM AUTHOR]

Nanostructured materials such as CoPt nanoparticles with tunable hard magnetic properties are desirable for a wide range of technological applications. In CoPt nanoparticle systems, a structurally disordered fcc phase may be transformed into an ordered fct L10 phase via annealing. However, the effects of this thermally induced disorder to order transition on the magnetic properties and phase coexistence still need to be understood. Here, we have studied these effects in Co50Pt50 nanoparticles, which were prepared by chemical reduction combined with ultrasound. By varying the annealing temperatures from 450 °C to 700 °C for 1 h, we observe that the magnetic properties are heavily dependent on the annealing temperature. The nanoparticles annealed at 500 °C exhibit the highest coercivity, while the 600 °C annealed nanoparticles possess the largest saturation magnetization. We demonstrate the variation in coercivity with annealing temperature follows that of the order parameter. This study establishes, for the first time, a correlation between the order parameter and the coercivity for annealed CoPt nanoparticles and paves a pathway for the development of nanostructured magnets with tunable magnetic properties.

Fruit nutritional value, plant growth, and yield can be compromised by deficient copper (Cu) bioavailability, which often appears in arable lands. This condition causes low Cu content and modifications in the ripening-associated processes in tomato fruit. This research studies the transcriptomic changes that occur in red ripe tomato fruit grown under suboptimal Cu conditions to shed light on the molecular mechanisms underlying this stress. Comparative RNA-sequencing and functional analyses revealed that Cu deficiency during cultivation activates signals for metal ion transport, cellular redox homeostasis, pyridoxal phosphate binding, and amino acid metabolism while repressing the response to phosphate starvation in harvested fruit. Transcriptomic analyses highlighted a number of novel Cu stress-responsive genes of unknown function and indicated that Cu homeostasis regulation in tomato fruit may involve additional components than those described in model plants. It also studied the regulation of high-affinity Cu transporters and a number of well-known Cu stress-responsive genes during tomato fruit ripening depending on Cu availability, which allowed potential candidates to be targeted for biotechnological improvements in reproductive tissues. We provide the first study characterizing the molecular responses of fruit to Cu deficiency stress for any fruit crop. [ABSTRACT FROM AUTHOR]

In the current situation, when the majority of the planet is urged to tolerate and accept, to promote peace and respect for other people and theyr choices, and culture, our fellow men in Egypt, Coptic Christians are fighting an unprecedented struggle against oppressors who demolish their churches and try to destroy their faith. Although we are far away physically, we cannot remain indifferent to what is happening to the cultural heritage they are trying to keep alive. This article reminds us of the wonderful artistic treasures found in Coptic culture.

Fruit nutritional value, plant growth, and yield can be compromised by deficient copper (Cu) bioavailability, which often appears in arable lands. This condition causes low Cu content and modifications in the ripening-associated processes in tomato fruit. This research studies the transcriptomic changes that occur in red ripe tomato fruit grown under suboptimal Cu conditions to shed light on the molecular mechanisms underlying this stress. Comparative RNA-sequencing and functional analyses revealed that Cu deficiency during cultivation activates signals for metal ion transport, cellular redox homeostasis, pyridoxal phosphate binding, and amino acid metabolism while repressing the response to phosphate starvation in harvested fruit. Transcriptomic analyses highlighted a number of novel Cu stress-responsive genes of unknown function and indicated that Cu homeostasis regulation in tomato fruit may involve additional components than those described in model plants. It also studied the regulation of high-affinity Cu transporters and a number of well-known Cu stress-responsive genes during tomato fruit ripening depending on Cu availability, which allowed potential candidates to be targeted for biotechnological improvements in reproductive tissues. We provide the first study characterizing the molecular responses of fruit to Cu deficiency stress for any fruit crop.

Topologically protected magnetic skyrmions in magnetic materials are stabilized by an interfacial or bulk Dzyaloshinskii-Moriya interaction (DMI). Interfacial DMI decays with an increase of the magnetic layer thickness in just a few nanometers, and bulk DMI typically stabilizes magnetic skyrmions at low temperatures. Consequently, more flexibility in the manipulation of DMI is required for utilizing nanoscale skyrmions in energy-efficient memory and logic devices at room temperature (RT). Here, we demonstrate the observation of RT skyrmions stabilized by gradient DMI (g-DMI) in composition gradient-engineered CoPt single-layer films by employing the topological Hall effect, magnetic force microscopy, and nitrogen-vacancy scanning magnetometry. Skyrmions remain stable over a wide range of applied magnetic fields and are confirmed to be nearly Bloch-type from micromagnetic simulation and analytical magnetization reconstruction. Furthermore, we observe skyrmion pairs, which may be explained by skyrmion-antiskyrmion interactions. Our findings expand the family of magnetic materials hosting RT magnetic skyrmions by tuning g-DMI via gradient polarity and a choice of magnetic elements.

Copper (Cu) plays a key role as cofactor in the plant proteins participating in essential cellular processes, such as electron transport and free radical scavenging. Despite high-affinity Cu transporters (COPTs) being key participants in Cu homeostasis maintenance, very little is known about COPTs in tomato (Solanum lycopersicum) even though it is the most consumed fruit worldwide and this crop is susceptible to suboptimal Cu conditions. In this study, a six-member family of COPT (SlCOPT1-6) was identified and characterized. SlCOPTs have a conserved architecture consisting of three transmembrane domains and β-strains. However, the presence of essential methionine residues, a methionine-enriched amino-terminal region, an Mx 3 Mx 12 Gx 3 G Cu-binding motif and a cysteine rich carboxy-terminal region, all required for their functionality, is more variable among members. Accordingly, functional complementation assays in yeast indicate that SlCOPT1 and SlCOPT2 are able to transport Cu inside the cell, while SlCOPT3 and SlCOPT5 are only partially functional. In addition, protein interaction network analyses reveal the connection between SlCOPTs and Cu P IB -type ATPases, other metal transporters, and proteins related to the peroxisome. Gene expression analyses uncover organ-dependency, fruit vasculature tissue specialization and ripening-dependent gene expression profiles, as well as different response to Cu deficiency or toxicity in an organ-dependent manner. • Six SlCOPT members were identified and characterized in Solanum lycopersicum. • SlCOPT structure is conserved but not the presence of key motifs for their function. • SlCOPT1 and SlCOPT2 can transport Cu from the extracellular matrix to the cytosol. • SlCOPT3 and SlCOPT5 are partially functional and might need to form heterocomplexes. • SlCOPT s respond differently and in an organ-dependent manner to Cu availability. [ABSTRACT FROM AUTHOR]

The moss Physcomitrium (Physcomitrella) patens is a bryophyte that provides genetic information about the adaptation to the life on land by early Embryophytes and is a reference organism for comparative evolutionary studies in plants. Copper is an essential micronutrient for every living organism, its transport across the plasma membrane is achieved by the copper transport protein family COPT/CTR. Two genes related to the COPT family were identified in Physcomitrella patens , Ppa COPT1 and Ppa COPT2. Homology modelling of both proteins showed the presence of three putative transmembrane domains (TMD) and the Mx 3 M motif, constituting a potential Cu + selectivity filter present in other members of this family. Functional characterization of Ppa COPT1 and Ppa COPT2 in the yeast mutant ctr1Δctr3Δ restored its growth on medium with non-fermentable carbon sources at micromolar Cu concentrations, providing support that these two moss proteins function as high affinity Cu + transporters. Localization of Ppa COPT1 and Ppa COPT2 in yeast cells was observed at the tonoplast and plasma membrane, respectively. The heterologous expression of Ppa COPT2 in tobacco epidermal cells co-localized with the plasma membrane marker. Finally, only Ppa COPT1 was expressed in seven-day old protonema and was influenced by extracellular copper levels. This evidence suggests different roles of Ppa COPT1 and Ppa COPT2 in copper homeostasis in Physcomitrella patens. Created with BioRender.com. [Display omitted] • Ppa COPT1 and Ppa COPT2 are phylogenetic related to the COPT family. • Ppa COPT1 and Ppa COPT2 possess three transmembrane domains and methionine motives important for copper selectivity. • Ppa COPT1 and Ppa COPT2 function as copper transporters according to functional complementation of the yeast mutant ctr1Δctr3Δ. • PpaCOPT1 and PpaCOPT2 are differentially localized to the tonoplast and plasma membrane, respectively. • Ppa COPT1 transcript is modulated by extracellular Cu concentrations probably contributing to Cu homeostasis in the moss. [ABSTRACT FROM AUTHOR]

The structural and magnetic properties of Co-Pt clusters up to five atoms with all possible combinations have been studied systematically. The global minimum energy structure of a cluster is obtained by optimizing its different possible geometries by using density functional theory (DFT) approximation. The electronic structure of the clusters were analyzed and found that the hybridization of 3d orbital of Co with the 5d orbital of Pt has enhancement effect on magnetization. The magnetic anisotropy energy of these small clusters is calculated from the free energy difference in two different noncolinear direction of spin alignment. It is found that the cluster with approximately equal number of Co and Pt atoms have larger anisotropy than the clusters with unequal number of Co and Pt of the same size. This can be explained by the combined effect of spin moment, orbital moment and the spin orbit coupling constant of the two materials.

In the current situation, when the majority of the planet is urged to tolerate and accept, to promote peace and respect for other people and theyr choices, and culture, our fellow men in Egypt, Coptic Christians are fighting an unprecedented struggle against oppressors who demolish their churches and try to destroy their faith. Although we are far away physically, we cannot remain indifferent to what is happening to the cultural heritage they are trying to keep alive. This article reminds us of the wonderful artistic treasures found in Coptic culture. [ABSTRACT FROM AUTHOR]

This letter demonstrates the fabrication and characterization of externally switchable electro-permanent magnets (EPMs) microfabricated on silicon wafers. Each EPM comprises a thick-film bilayer of electroplated cobalt-platinum as the hard magnetic phase and screen-printed aluminum-nickel-cobalt/polydimethylsiloxane composite as the soft magnetic phase. The selected magnetic materials and corresponding fabrication methods are compatible with standard semiconductor processes, which enable batch fabrication capability for low-cost and system-on-chip integration. An on/off magnetic moment ratio of 265 is achieved for the miniaturized 3.6 mm × 3.6 mm × 0.3 mm EPM devices by varying the volume ratio of the constituent materials. Scanning electron microscopy and vibrating sample magnetometry are used to characterize the microscopic structure and magnetic performance of the fabricated devices, respectively. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungi are critical participants in plant nutrition in natural ecosystems and in sustainable agriculture. A large proportion of the phosphorus, nitrogen, sulfur, and transition metal elements that the host plant requires are obtained from the soil by the fungal mycelium and released at the arbuscules in exchange for photosynthates. While many of the plant transporters responsible for obtaining macronutrients at the periarbuscular space have been characterized, the identities of those mediating transition metal uptake remain unknown. In this work, MtCOPT2 has been identified as the only member of the copper transporter family COPT in the model legume Medicago truncatula to be specifically expressed in mycorrhizal roots. Fusing a C-terminal GFP tag to MtCOPT2 expressed under its own promoter showed a distribution pattern that corresponds with arbuscule distribution in the roots. When expressed in tobacco leaves, MtCOPT2-GFP co-localizes with a plasma membrane marker. MtCOPT2 is intimately related to the rhizobial nodule-specific MtCOPT1, which is suggestive of a shared evolutionary lineage that links transition metal nutrition in the two main root endosymbioses in legumes. [ABSTRACT FROM AUTHOR]

This is a proposal to add characters for Coptic to the international character encoding standard Unicode. The characters were published in Unicode Standard version 4.1 in March 2005. Before Unicode version 4.1, Coptic was treated as a stylistic variant of Greek. The "Greek and Coptic" block of characters in Unicode included 14 Coptic characters. This document proposed the remaining characters that are needed for the representation of Coptic text. They were published in the "Coptic" block in Unicode 4.1. It includes logotypes used in Coptic as well as Nubian and Old Coptic characters.

For solid-state magnetic memories and other potential devices based on giant magnetoresistance and tunneling magnetoresistance effects, it is invariably required that one ferromagnetic layer remains with its magnetization pinned in a given direction. The other ferromagnetic layer is then free to rotate creating the magnetoresistive effect. The fixing or pinning of one of the ferromagnetic layers can be achieved by using a material with a high coercivity or significantly higher anisotropy than the other layer. In conventional devices with in-plane anisotropy, this is achieved by the use of the exchange bias phenomenon where the pinned layer is coupled to an antiferromagnetic layer typically consisting of IrMn. In this paper, we consider strategies to achieve the exchange bias phenomena in materials with strong perpendicular orientation to the magnetization and the potential for achieving the required exchange bias. We report on successfully achieving this objective in a (Co/Pt)n system. We have achieved values of loop shift approaching 700 Oe at room temperature and blocking temperatures in excess of 500 K. [ABSTRACT FROM AUTHOR]

This paper reports the fabrication and magnetic characterization of very thick ($50+ \mu \text{m}$) and high-performing (coercivity up to 850 kA/m; energy products up to $75 \text{kJ}/\text{m}^{3}$) electroplated permanent magnets microfabricated on silicon substrates. Intended for MEMS applications, the fabrication process yields higher areal magnetic energy density ($5.6 \text{J}/\text{m}^{2}$) and faster plating rates ($42~\mu \text{m}/\text{h}$) compared with previously published work. The magnetic CoPt alloy is co-plated in single electroplating bath and subsequently annealed at 675 °C for 30 min to induce a phase transformation to the high-coercivity $\text{L}1_{0}$ CoPt phase. Compared with the previous literature on electroplated CoPt films, four main accomplishments are reported: 1) optimization of the underlying seed layer metallurgy to improve film adhesion and inhibit interfacial diffusion/reactions; 2) development of a warm-bath (50 °C), high-current-density (300–2000 mA/cm2) electroplating process that dramatically increases plating rate while maintaining good magnetic properties; 3) study of the electroplating bath longevity; and 4) exploration of the nanostructure of the electroplated magnets by TEM/STEM. [2018-0222] [ABSTRACT FROM AUTHOR]

CoxPt100−x nanoparticles (x = 50, 59, and 73) were prepared by the chemical reduction of Cobalt (II) chloride and Chloroplatinic acid, then ultrasonicated for 2 h. After annealing at various temperatures from 450 °C to 700 °C for 1 h, structure change was observed and samples show hard magnetic properties which depend strongly on chemical composition and annealing temperature. The highest coercivity value of 1.15 kOe was obtained at room temperature for sample with x = 50 annealed at 500 °C. Chemical reduction combined with ultrasound is a useful method to prepare CoPt nanoparticles.

Highlights • CoPt-Cu nanoparticles synthesized by a simple one-step polyol process. • Curie temperature of CoPt reduced by Cu incorporation. • High coercivity of 9.5 kOe achieved in CoPt-Cu. • Inter-particle interactions studied through δM measurements. Abstract Co 30 Cu 10 Pt 60 nanoparticles were prepared by a simplified polyol process devoid of any surfactants or capping agents. Thermo-magnetic analysis showed that the addition of 10 at.% Cu reduces the Curie temperature of Co 40 Pt 60 from 492 °C to 435 °C. The incorporation of Cu is effective in reducing the threshold ordering temperature for the A1-fcc to L1 0 -fct phase transformation of CoPt, resulting in coercivity enhancement. Coercivity close to 10 kOe at a lower annealing temperature of 600 °C in Co 30 Cu 10 Pt 60 demonstrates that high coercivity in CoPt can be achieved in non-equiatomic compositions also. Annealing temperature dependent two phase behavior has been understood by δM studies. [ABSTRACT FROM AUTHOR]

In this work, alloying of CoPt and FePt nanoparticles (NPs), i.e. the Co 1-x Fe x Pt NPs (x = 0, 0.25, 0.5, 0.75, 1), were synthesized by the polyol process. These as-synthesized NPs show the A1 phase with a particle size less than 5 nm. After annealing at 700 °C, the A1 (cubic) phase was transformed to L1 0 (tetragonal) phase in all samples. The lattice parameters varied as a function of the composition. The particle size grew larger after annealing and the size distribution was wide ranging from <10 nm to >100 nm. The size and distribution was however independent of the Co(Fe) concentration. X-ray absorption spectroscopy indicated that there was a random distribution of Co and Fe atoms in the layered structure. Magnetic measurements of the annealed NPs showed that the magnetic hysteresis loop depends on the composition. The coercivity (H c ) was very high for the CoPt and FePt NPs, whereas the M s value was maximized for the Co 0.5 Fe 0.5 Pt NPs. The variation of H c was attributed to the change in lattice parameters which could alter the exchange interaction, and thus the magnetocrystalline anisotropy. On the other hand, higher polarization and increased magnetic moments of Fe atoms were believed to be the reason for the enhanced M s in the Co(Fe)Pt NPs. In addition, all NPs were magnetically stable against temperature variation with changes in M s of less than 10%. The Curie temperature was expected to be as high as 800–900 K. Given these properties, these new forms of magnetic nanoparticles may find use in advanced magnetic recording technology. [ABSTRACT FROM AUTHOR]

The effect of nitrogen incorporation on the L 1 0 ordering transformation of CoPt thin films deposited by dc magnetron sputtering on MgO substrate with/without TiN seed layers has been investigated. Without TiN seed layer, CoPt film is subjected to a tensile stress, and the perpendicular magnetic anisotropy (PMA) decreases with N 2 gas flow ratio. This is due to the degradation of tensile stress, which is proven to be beneficial to the ordering transformation of L 1 0 CoPt. On the contrary, when sputtered on TiN seed layer, CoPt film is subjected to a compressive stress and the PMA increases with N 2 gas flow ratio. The increase of PMA is due to the increase in equilibrium vacancy concentration, which also promotes the diffusion of Co and Pt atoms during annealing. On quartz substrate, the maximum perpendicular coercivity of 11 kOe was obtained at the CoPt/TiN bilayer films with 50% partial N 2 gas flow ratio after post annealing at 700 °C. By partially flowing nitrogen during the deposition, a 200 °C reduction of ordering temperature was also obtained. [ABSTRACT FROM AUTHOR]

The thermally activated formation of nanoscale CoPt alloys was investigated, after deposition of self-assembled Co nanoparticles on textured Pt(111) and epitaxial Pt(100) films on MgO(100) and SrTiO3(100) substrates, respectively. For this purpose, metallic Co nanoparticles (diameter 7 nm) were prepared with a spacing of 100 nm by deposition of precursor-loaded reverse micelles, subsequent plasma etching and reduction on flat Pt surfaces. The samples were then annealed at successively higher temperatures under a H2 atmosphere, and the resulting variations of their structure, morphology and magnetic properties were characterized. We observed pronounced differences in the diffusion and alloying of Co nanoparticles on Pt films with different orientations and microstructures. On textured Pt(111) films exhibiting grain sizes (20–30 nm) smaller than the particle spacing (100 nm), the formation of local nanoalloys at the surface is strongly suppressed and Co incorporation into the film via grain boundaries is favoured. In contrast, due to the absence of grain boundaries on high quality epitaxial Pt(100) films with micron-sized grains, local alloying at the film surface was established. Signatures of alloy formation were evident from magnetic investigations. Upon annealing to temperatures up to 380 °C, we found an increase both of the coercive field and of the Co orbital magnetic moment, indicating the formation of a CoPt phase with strongly increased magnetic anisotropy compared to pure Co. At higher temperatures, however, the Co atoms diffuse into a nearby surface region where Pt-rich compounds are formed, as shown by element-specific microscopy.

Monatomic (Fe, Co) and bimetallic (FePt and CoPt) nanoparticles were prepared by exploiting the self-organization of precursor loaded reverse micelles. Achievements and limitations of the preparation approach are critically discussed. We show that self-assembled metallic nanoparticles can be prepared with diameters d = 2–12 nm and interparticle distances D = 20–140 nm on various substrates. Structural, electronic and magnetic properties of the particle arrays were characterized by several techniques to give a comprehensive view of the high quality of the method. For Co nanoparticles, it is demonstrated that magnetostatic interactions can be neglected for distances which are at least 6 times larger than the particle diameter. Focus is placed on FePt alloy nanoparticles which show a huge magnetic anisotropy in the L10 phase, however, this is still less by a factor of 3–4 when compared to the anisotropy of the bulk counterpart. A similar observation was also found for CoPt nanoparticles (NPs). These results are related to imperfect crystal structures as revealed by HRTEM as well as to compositional distributions of the prepared particles. Interestingly, the results demonstrate that the averaged effective magnetic anisotropy of FePt nanoparticles does not strongly depend on size. Consequently, magnetization stability should scale linearly with the volume of the NPs and give rise to a critical value for stability at ambient temperature. Indeed, for diameters above 6 nm such stability is observed for the current FePt and CoPt NPs. Finally, the long-term conservation of nanoparticles by Au photoseeding is presented.

The material and magnetic properties of multi-micron-thick (up to 6 μm) L1 0 CoPt magnetic films electroplated onto silicon substrates are investigated as candidate materials for integration in silicon-based microsystems. The influence of various process conditions on the structure and magnetic properties of electroplated CoPt thick-films is studied in order to better understand the complex process/structure/property relationships associated with the electroplated films. Process variables studied here include different seed layers, electroplating current densities (ranging from 25–200 mA/cm 2 ), deposition times (up to 60 min), and post-deposition annealing times and temperatures. Analyses include film morphology, film thickness, composition, surface roughness, grain size, phase volume fractions, and L1 0 ordering parameter. Key correlations are found relating process and structure variations to the extrinsic magnetic properties (remanence, coercivity, squareness, and energy product). Strong hard magnetic properties ( B r ~0.8 T, H ci ~800 kA/m, squareness close to 0.9, and BH max of 100 kJ/m 3 ) are obtained for films deposited on Si/TiN/Ti/Cu at current densities of 100 mA/cm 2 , pH of 7, and subsequently annealed at 675 °C for 30 min. [ABSTRACT FROM AUTHOR]

This study addresses the adequacy of a generating system considering the impact of operation strategies of storages and hydro energy resources. It is assumed that the installed storage capacity of a system can be assigned for two purposes: first, economical operation which adopts storage to shift electric energy and smooth the load curve; and the second, reliability‐based operation, which deploys storage to avoid load curtailments. The economical operation strategy is represented by starting from time domain data and using the load curve modification method to synthesise the overall impact of storage. The reliability‐based operation is modelled with a new method based on Markov chain model that considers the dynamic behaviour of storage during time. Moreover, a novel state reduction method is presented for decreasing the number of Markov states in applications to large systems. The effectiveness of the presented methods is evaluated by running several simulation scenarios with results presented on three test systems. The results demonstrate that evaluating the system reliability in the presence of energy storage by considering the frequency and duration of system states is more effective than using methods based on the Capacity Outage Probability Table (COPT). [ABSTRACT FROM AUTHOR]

ABA is involved in plant responses to non-optimal environmental conditions, including nutrient availability. Since copper (Cu) is a very important micronutrient, unraveling how ABA affects Cu uptake and distribution is relevant to ensure adequate Cu nutrition in plants subjected to stress conditions. Inversely, knowledge about how the plant nutritional status can interfere with ABA biosynthesis and signaling mechanisms is necessary to optimize stress tolerance in horticultural crops. Here the reciprocal influence between ABA and Cu content was addressed by using knockout mutants and overexpressing transgenic plants of high affinity plasma membrane Cu transporters (pmCOPT) with altered Cu uptake. Exogenous ABA inhibited pmCOPT expression and drastically modified COPT2-driven localization in roots. ABA regulated SPL7, the main transcription factor responsive for Cu deficiency responses, and subsequently affected expression of its targets. ABA biosynthesis (aba2) and signaling (hab1-1 abi1-2) mutants differentially responded to ABA according to Cu levels. Alteration of Cu homeostasis in the pmCOPT mutants affected ABA biosynthesis, transport and signaling as genes such as NCED3, WRKY40, HY5 and ABI5 were differentially modulated by Cu status, and also in the pmCOPT and ABA mutants. Altered Cu uptake resulted in modified plant sensitivity to salt-mediated increases in endogenous ABA. The overall results provide evidence for reciprocal cross-talk between Cu status and ABA metabolism and signaling. [ABSTRACT FROM AUTHOR]

Accumulating evidence highlights mitochondrial dysfunction as a crucial factor in the pathogenesis of acute kidney injury (AKI); thus, novel therapeutic strategies maintaining mitochondrial homeostasis are highly anticipated. Recent studies have shown that cobaltosic oxide has peroxidase-like catalytic activities, although its role and mechanism remain elusive in AKI. In the present study, we synthesized and identified cobaltosic oxide-polyethylene glycol-triphenylphosphine (COPT) nanoparticles by conjugating cobaltosic oxide with polyethylene glycol and triphenylphosphine, to improve its biocompatibility and mitochondria-targeting property. We found that COPT preferentially accumulated in the kidney proximal tubule cells, and significantly alleviated ischemic AKI in mouse models and gentamicin induced-AKI in the zebrafish model. COPT also inhibited the transition from AKI to chronic kidney disease (CKD), with few side effects. Further studies demonstrated that COPT localized in the mitochondria, and ameliorated hypoxia-reoxygenation-mediated mitochondrial damage through enhancing mitophagy in vitro and in vivo. Mechanistically, COPT dose-dependently induced the expression of Bcl-2/adenovirus E1B 19-kDa interacting protein (BNIP3), while knockdown of BNIP3 attenuated COPT-induced mitophagic flux and mitochondrial protection. Thus, our findings suggest that COPT nanoparticles ameliorate AKI and its progression to CKD through inducing BNIP3-mediated mitophagy, indicating that COPT may serve as a promising mitochondria-targeting therapeutic agent against AKI., (Copyright © 2023 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)

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Co 50−X M X Pt 50 (M = Cu or Ru) films were magnetron sputtered on textured Pt(111) underlayer on glass substrate at 350 °C. The results show that perpendicular magnetic anisotropy of superlattice L 1 1 phase can be maintained well with doping Cu element into CoPt film. Out-of-plane coercivity ( H c ⊥ ) was also increased with the increase of Cu content. However, disordered A 1(111) structure and lower H c ⊥ were obtained with the addition of Ru element in CoPt film. The magnetic force microscopy images indicated that doping Cu diminished the domain size. Oppositely, doping Ru made the domain reversed incompletely. Surface morphology of Co 24 Cu 26 Pt 50 thin film was much smoother than that of Co 23 Ru 27 Pt 50 thin film, indicative of maintenance of the epitaxial growth of L 1 1 (111) from flat Pt(111) underlayer. The transmission electron microscopy (TEM) images show that the Cu element could be incorporated in L 1 1 CoPt grains; however, the RuPt alloy was segregated at CoPt grain boundary. The cross section TEM pictures showed that the columnar structures starting from Pt(111) underlayer and extending into magnetic CoCuPt(111) layer confirmed that epitaxy existed at CoCuPt/Pt interface. Our research demonstrates that replacing Co with Cu = 23–26 at.% effectively increases the perpendicular magnetic properties of L 1 1 CoPt phase, which largely increase the potential of L 1 1 films for the application of perpendicular magnetic media and advance spintronic device. [ABSTRACT FROM AUTHOR]

Mixtures of powders of platinum with nickel or cobalt to obtain Ni 0.75 Pt 0.25 or Co 0.75 Pt 0.25 were mechanical alloyed by high energy ball milling. The results of crystal structure, morphology and electrocatalytic performance are presented for mechanically activated powders after 3 and 9 h of ball milling. Total solid solutions of Ni and Co with platinum were analyzed by X-ray diffraction after 3 h of ball milling. After 9 h of ball milling, in both cases, the total solid solution was accompanied by the appearance of NiO or CoO and ZrO associated with a redox reaction with the milling media. The presence of zirconium monoxide was confirmed by energy dispersive spectroscopy analysis. In both cases, an amorphization was detected. X ray absorption spectroscopy measurements showed changes in atomic and electronic environment of platinum, a reduction of the distance to the first coordination sphere and increased d-band vacancy vs pure Pt and Pt nanoparticles were observed for both studied systems. The electrocatalytic activity was determined using cyclic and linear voltammetry. The Co 0.75 Pt 0.25 alloy milled for 9 h showed a higher electrochemical activity for the oxygen reduction reaction (ORR) compared with the other samples, including Pt-Etek. The degree of the ORR electrochemical activity was correlated with the presence of ZrO, which could affect the oxygen adsorption and improve the catalytic activity for the oxygen reduction reaction. [ABSTRACT FROM AUTHOR]

The presence of H along with an inert gas during annealing was considered as a prerequisite in achieving high coercivity in alloys such as FePt and CoPt nanoparticles synthesized through chemical methods. CoPt nanoparticles were synthesized using a one-step polyol process without using any surfactant and annealed at various temperatures in N atmosphere. The magnetic properties of Co Pt sample annealed at 700 C in N atmosphere showed a room temperature coercivity of 8.4 kOe. The magnetic interactions present in the samples were studied using δM measurements. The evolution of high coercivity in the samples annealed at 700 C showed that N is a cheaper alternative to the existing reducing gas mixture. [ABSTRACT FROM AUTHOR]

Co49Pt51 alloy films with strong perpendicular magnetic anisotropy (PMA) have been most often grown on either single crystal or glass substrates with deposition temperature of about 350°C using Pt/Ru as an underlayer. In contrast, in this study, 5-nm thick Co49Pt51 alloy films with significant PMA were fabricated on glass substrates at room temperature (RT) using a combination of Ta and Pt underlayers. The structural and magnetic properties of the Co49Pt51 films obtained at RT (RT-CoPt) were compared with that of those produced by the conventional high-temperature route (HT-CoPt). The x-ray diffraction studies showed the evolution of highly textured Pt (111) peak accompanied by a CoPt (222) shoulder for the RT-CoPt films, similar to that of the HT-CoPt films. The microstructural studies revealed extremely smooth surface with root mean square roughness (R rms) of 0.5nm for the RT-CoPt films, while the HT-CoPt films showed wavy surface with R rms of 2.4nm. The out-of-plane and in-plane hysteresis loops demonstrated the existence of strong PMA for both the RT-CoPt and HT-CoPt films. The estimated magnetic parameters for the RT-CoPt films such as squarness ratio, SQR (0.96), perpendicular coercivity, H c⊥ (822Oe) and magneto-crystalline anisotropy constant, K u (6.4×106 erg/cm3) was found to be comparable to that of those obtained with the HT-CoPt films (SQR=0.96, H c⊥=1810Oe and K u=7.1×106 erg/cm3). [ABSTRACT FROM AUTHOR]

The effects of sputter growth conditions of Ru-SiO2 under-layer (hereafter referred as Rut layer) on the microstructure of this layer were studied. The effects of growth conditions of the Rut layer on the microstructure and magnetic properties of the Co72Pt28-SiO2 top layer were further investigated. Results show that increasing SiO2 content in the Rut layer deteriorates slightly the texture of Ru grains in this layer generally. The high-pressure (1.3 Pa) deposition can better protect the texture of Ru than low-pressure (0.4 Pa) deposition with SiO2 addition. Furthermore, high-pressure deposition of Rut layer with low SiO2 content produces better texture of Co72Pt28 than low pressure. The sizes of Ru grains and Co72Pt28 grains decrease with increasing SiO2 content. A high-pressure deposition of Rut layer further reduces the grain size of Co72Pt28. Both the coercivity and the remanence ratio of Co72Pt28 layer decrease when SiO2 content in the Rut layer exceeds 10 vol.%. High-pressure deposition of Rut layer results in a higher coercivity and remanence ratio of Co72Pt28 layer than those with low-pressure depositions. The above results show that the grain size of Co72Pt28 can be reduced without sacrificing its magnetic properties at small SiO2 content. [ABSTRACT FROM AUTHOR]

This study analyses the relationship between the Coptic community in the United States and Egyptian Copts regarding the status of Coptic citizenship in the Egyptian state. The conception of citizenship for the Coptic Christian minority has been debated since the formation of the modern nation-state and has acquired greater relevance after the revolution that brought the Muslim Brotherhood to power. One primary narrative of citizenship is promoted by the Egyptian Church. It recognises that, while Copts may not feel like equal citizens, they are devoted to their homeland. They try to promote greater equality through civil discourse, opposing foreign intervention and seeking to foster positive relations with Egypt's Muslims. While many Diaspora Copts echo the message of the Egyptian Church, a minority of activist Copts have challenged that narrative. Inculcated with ideas of Islamophobia and neoconservatism, they tend to dismiss hopes of national unity and focus rather on incidents of persecution. These diaspora activist groups continue to challenge the Coptic Church. Their policies have influenced American foreign policy and have broader implications for Muslim-Christian relations in Egypt. [ABSTRACT FROM AUTHOR]

Abstract: L11 type CoPt superstructure, a rhombohedral meta-stable phase, thin films with different thickness (t) were sputtered on glass, Pt/glass, and MgO(111) substrates. Perpendicular magnetic anisotropy (PMA) is obtained as the CoPt films, which are deposited on Pt(111)/glass and MgO substrates. The coercivity (H c) of CoPt/Pt/glass is higher than that of CoPt/MgO(111) film due to the smaller lattice misfit at CoPt/Pt interface and domain wall impedance at CoPt grain boundary. For the CoPt/Pt/glass and CoPt/MgO films, H c usually increases with reducing the t from 50nm to 5nm. This result could be attributed to the roughness effect at CoPt/Pt and CoPt/MgO interfaces. Without Pt underlayer, CoPt thin film exhibits soft magnetic phase on glass substrate. In this study, higher H c of about 141kA/m is shown on 3nm-thick CoPt film on Pt/glass. The improvement of perpendicular magnetic properties are obtained by replacing the MgO(111) with Pt/glass, inducing high potential of L11 CoPt in future applications. [Copyright &y& Elsevier]

Abstract: Magnetic force microscope (MFM) tips are prepared by coating Si tips of 4nm radius with FePd, FePt, and CoPt films of 80nm thickness at room temperature followed by annealing at 600°C. The spatial resolution and the switching field are investigated. The resolution of about 9nm is realized for all the tips. On the contrary, the switching fields of FePd-, FePt-, and CoPt-coated tips are 117.4, 37.8, and 268.6 kA/m, respectively. The crystal structure and the magnetic properties of coated magnetic thin films prepared on flat Si substrates are measured and the interrelationships with the MFM tip characteristics are briefly investigated. [Copyright &y& Elsevier]

Highlights: [•] We propose a mechanism of phase formation in Pt/Co bilayers during ion beam mixing. [•] We examine the influence of heat of formation during ion beam mixing in Pt/Co bilayers. [•] Parameters deciding phase synthesis during ion mixing in Pt/Co bilayers are explored. [ABSTRACT FROM AUTHOR]

Perpendicularly magnetized CoPt films with L11 rhombohedral lattice were deposited on glass substrates with a Pt underlayer. The results show that the magnetic properties of CoPt films are substantially affected by post-annealing time (ta) and temperature (Ta) of Pt underlayer, as well as the thickness of Pt underlayer (tPt). Soft magnetic phase is formed as CoPt is directly deposited on the glass substrate at 350^\circC. Besides, a very low coercivity (H c) of 103 kA/m is obtained when ta, Ta, and tPt are 5 min, 300^\circC, and 20 nm, respectively. Further varying ta, Ta, and tPt to 15 min, 350^\circC, and 25 nm increases Hc to about 207 kA/m. The microstructural studies indicate that the size of CoPt grain is the key factor to determine the magnetic properties, which could be controlled by the formation conditions of Pt underlayer. In this study, the optimum deposition conditions for Pt underlayer to obtain L11 CoPt phase with high Hc are ta = 15 min, Ta = 350^\circC, and tPt = 20\--25 nm. Our study demonstrates that using a Pt underlayer/glass substrate can effectively replace the single-crystal substrate and also enhance Hc of CoPt film, which may increase the application potential of L11 CoPt film in the future. [ABSTRACT FROM AUTHOR]