The shift to sustainable energy has accelerated the development of thermoelectric (TE) material for direct heat-to-electricity conversion without batteries or grid reliance. Cu-Ni alloys show promise for high-power, thermally stable TE applications like waste heat recovery and electronics cooling but require thermal conductivity and microstructure optimization. This study investigates additive manufacturing (AM) of Cu-Ni alloys via laser powder-directed energy deposition (L-DED), enabling precise control over deposition parameters. Track geometries were analyzed using linear mass density (ML) and linear heat input (HL), which influence deposition quality and microstructural characteristics. A weighted qualitative process parameter decision matrix was developed to evaluate process conditions systematically. Optimal deposition was achieved with HL < 70 J/mm for ML ~0.016–0.021 g/mm and 98 J/mm < HL < 137 J/mm for ML = 0.026 g/mm, corresponding to an energy-to-mass ratio of ~4000 ± 500 kJ/g. While this study does not directly assess thermoelectric properties, it provides essential first-layer insights into how processing conditions affect track geometry, defect formation, and microstructure—information that is foundational for optimizing multi-layer builds and, ultimately, improving thermoelectric performance. These findings mark a critical step toward predictive process optimization and the accelerated design of Cu-Ni-based thermoelectric materials using AM techniques.

Magnetic refrigeration is an energy-efficient, sustainable, environmentally-friendly alternative to the conventional vapor-compression cooling technology. There are several magnetic refrigerator device designs in existence today that are predicted to be highly energy-efficient, on condition that suitable working materials can be developed. This challenge in manufacturing magnetocaloric devices is unresolved, mainly due to issues related to shaping the mostly brittle magnetocaloric alloys into thin-walled channeled regenerator structures to facilitate efficient heat transfer between the solid refrigerant and the heat exchange fluid in an active magnetic regenerator (AMR) cooling device. To address this challenge, a novel extrusion-based additive manufacturing (AM) method has been developed to 3D print microchanneled magnetocaloric structures. The printing ink consists of magnetocaloric powders, a polymer binder, and multiple solvents to achieve desirable shear-thinning property, which is critical for a robust printing process. Acting as a sacrificial binding agent for the magnetic powders, the polymer binder holds the 3D printed structures in place and is removed subsequently using a two-step heat-treatment process. To demonstrate the effectiveness of the fabrication process, spatially designed microchannels with minimum dimensions of 150 mu m were achieved using nanoscaled La0.6Ca0.4MnO3 powders (diameter~10 nm). Results indicate that the crystallographic properties and magnetofunctional response of the sintered 3D printed samples are comparable to that of the precursor powders. Overall, this study provides a promising route for realizing lowcost magnetic regenerators, thus potentially eliminating one of the main barriers to the commercialization of magnetic cooling technology.(c) 2022 Elsevier B.V. All rights reserved.

Y Membrane proteins (MPs) play essential roles in biological and pharmacological processes. Many of them require cholesterol (CHOL) as their structure supportive lipid component and modulator for functionality. Unfortunately, commercially available CHOL and its derivatives have limitations on solubility or bio-activity. We report 4-((cholesteryloxy)-4-oxobut-2-enamido)ethyl) dimethylam-monio) propane-1-sulfonate (CHEAPS), a novel CHOL alternative for MP study. CHEAPS can be readily solubilized in both detergents and membrane-active polymers. Interestingly, it could stabilize and support a new discovered enzyme function of human mitochondrial TSPO. As such CHEAPS may have a broad application for MP structural biology.

Building on previous work finding a significant magnetocaloric effect (MCE) in manganite nanoparticles having the formula La0.60Cax Sr0.40-xMnO3 (0

Caves on Rapa Nui that possess well-constructed tunnel entrance features are currently interpreted as places of temporary refuge (ana kionga) used in the late seventeenth century during a period of internal island conflict. The analysis of the cave interior architecture and artifact assemblage from Site 6-357 suggests an alternate interpretation where the caves may have served as prepared ritual spaces where food consumption, sewing and body adornment were conducted. Radiocarbon and obsidian hydration dating indicate that the caves were most likely constructed after European contact and were not present at an earlier time.

Magnetic nanomaterials have many applications in the fields of catalysis, medicine, and environmental studies. An emerging synthetic method capable of large-scale production of nanomaterials is a continuous-flow microreactor. However, translating known conventional benchtop reactions to a continuous-flow system can be difficult; reaction parameters such as reaction time and viscosity of the solution are significant limitations in flow-based systems. In this study, nanocrystalline Cu-Ni and Cu-Co core-shell materials were successfully synthesized using a capillary microreactor in a one-step process. Ethanol was used as solvent, allowing for faster reaction times and reduced reaction solution viscosity, compared to similar bench top synthetic protocols. Both nanocomposites were tested for activity in Fischer-Tropsch and showed activity above 220 °C. This study shows that a continuous-flow capillary microreactor has the capabilities to make complex metallic nanomaterials at short reaction times with proper selection of reaction solvent systems.

A comparative magnetic study was conducted on Fe3C and Fe3C/CoO for potential enhancement in magnetic properties due to exchange interaction in ferro/antiferromagnetic systems. X-ray diffraction confirmed the presence of iron carbide and CoO while XPS determined presence of a CoFe2O4 and a small percent of FexCoxC at the interface. Transmission electron microscopy showed a polydispersed network of 47 nm of Fe3C coated with 17 nm CoO nanoparticles. Due to the intrinsic nature of the interface an enhanced coercivity (600 Oe) above the blocking temperature was observed in comparison to the bare Fe3C nanoparticles (450 Oe). Upon cooling below the Neel temperature and Verwey temperature for CoO and CoFe2O4 a maximum exchange bias of 150 Oe occurred at 50 K. Results have shown a plausible way to enhance the anisotropy of the iron carbide while broadening its potential applications for spin valve systems. (C) 2017 Elsevier B.V. All rights reserved.

Perovskite manganite La0.6Ca0.4MnO3 (LCMO) nanomaterials were synthesized by a modified Pechini sol–gel process followed by high temperature sintering.

Precise control over the magnetic properties of FeCo alloys is of scientific significance, due to their high Curie points and saturation magnetizations, and of broad interest for applications such as transformer cores, induction motors, switching devices, and hyperthermia. The magnetic properties of FexCo(1-x) alloy-based nanopowders prepared by polyol synthesis and their relationship with morphological features and the evolution of the microstructure were investigated using a design of experiments (DoE) approach. Proportionalities related to the magnetic properties, saturation magnetization (Ms) and coercivity (Hc), were identified where Ms ∝ (110) crystallite size of FeCo (bcc) and Hc ∝ particle diameter for the as-synthesized FexCo(1-x) nanopowders. Adjusting the reaction composition allows for control of the FeCo (bcc) (110) crystallite size from 20-45 nm represented by a response surface model. Morphological features of the as-synthesized nanopowders include particles interlinked as chains, and particles either in the form of cuboids or spheroids, all with diameters ranging from 75-175 nm. FexCo(1-x) alloy was confirmed by XRD in each nanopowder while few contained a combination of phases which include Co (fcc), or ferrite (CoFe2O4), or both. Depending on composition, particle dimension, and microstructure, the Ms ranged from 90-215 emu g-1 with Hc from 90-400 Oe for all nanopowders synthesized by the sub-reflux, isothermal condition (150 °C). Tailoring the magnetic properties of FexCo(1-x) alloy-based nanopowders is accomplished chemically by identifying and regulating significant reaction parameters and conditions.

A phase transition, from orthorhombic Fe3C to hexagonal Fe7C3, was observed using a wet synthesis mediated by hexadecyltrimethylammonium chloride (CTAC). In this study, CTAC has been shown to control carbide phase, morphology, and size of the iron carbide nanostructures. Fe7C3 hexagonal prisms were formed with an average diameter of 960 nm, the thickness of 150 nm, and Fe3C nanostructures with an approximate size of 50 nm. Magnetic studies show ferromagnetic behavior with Ms of 126 emu/g, and Hc of 170 Oe with respect to Fe7C3 and 95 emu/g and 590 Oe with respect to Fe3C. The thermal studies using high temperature x-ray diffraction show stability of Fe7C3 up to 500 °C. Upon slow cooling, the Fe7C3 phase is recovered with an intermediate oxide phase occurring around 300 °C. This study has demonstrated a simple route in synthesizing iron carbides for an in depth magnetic study and crystal phase transition study of Fe7C3 at elevated temperatures.

CuPd bi-metallic nanoparticles prepared by facile oleylamine synthesis as an efficient catalyst in carbon–carbon cross-coupling reactions with multiple recyclability and excellent turnover frequency.

Magnetic Fe and Fe3O4 (magnetite) nanoparticles are successfully synthesized using Aspergillus niger YESM 1 and supercritical condition of liquids. Aspergillus niger is used for decomposition of FeSO4 and FeCl3 to FeS and Fe2O3, respectively. The produced particles are exposed to supercritical condition of ethanol for 1 hour at 300°C and pressure of 850 psi. The phase structure and the morphology measurements yield pure iron and major Fe3O4 spherical nanoparticles with average size of 18 and 50 nm, respectively. The crystal size amounts to 9 nm for Fe and 8 nm for Fe3O4. The magnetic properties are measured to exhibit superparamagnetic- and ferromagnetic-like behaviors for Fe and Fe3O4 nanoparticles, respectively. The saturation magnetization amounts to 112 and 68 emu/g for Fe and Fe3O4, respectively. The obtained results open new route for using the biophysical method for large-scale production of highly magnetic nanoparticles to be used for biomedical applications.

FeCo magnetically aligned linear chains (MALCs) were synthesized using polyol based co-precipitation chemistry under an external dynamic magnetic field and are potential candidates for magnetic switching devices and radar absorbing materials (RAMs).

Attainment of magnetic order in nanoparticles at room temperature is an issue of critical importance for many different technologies. For ordinary ferromagnetic materials, a reduction in size leads to decreased magnetic anisotropy and results in superparamagnetic relaxations. If, instead, anisotropy could be enhanced at reduced particle sizes, then it would be possible to attain stable magnetic order at room temperature. Herein, we provide experimental evidence substantiating the synthesis of a cobalt iron carbide phase (CoFe2C) of nanoparticles. Structural characterization of the CoFe2C carbide phase was performed by transmission electron microscopy, electron diffraction and energy electron spectroscopy. X-ray diffraction was also performed as a complimentary analysis. Magnetic characterization of the carbide phase revealed a blocking temperature, TB, of 790 K for particles with a domain size as small as 5 ± 1 nm. The particles have magnetocrystalline anisotropy of 4.6 ± 2 × 106 J/m3, which is ten times larger than that of Co nanoparticles. Such colossal anisotropy leads to thermally stable long range magnetic order. Moreover, the thermal stability constant is much larger than that of the commonly used FePt nanoparticles. With thermal stability and colossal anisotropy, the CoFe2C nanoparticles have huge potential for enhanced magnetic data storage devices.