Compositional effects of rice husk based activated carbon on properties of steel waste derived magnetite nanoparticles

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A strong societal and political drive is motivating the development and optimization of novel energy conversion and storage systems for decarbonization. The successful implementation of solid state devices such as fuel cells and secondary batteries depends, however, on achieving ambitious targets in terms of performance, reliability and cost competitiveness. Research and technology are addressing these needs through a holistic approach including exploration of new materials and nano

Early identification of neurodevelopmental disorders relies on accurate segmentation of brain structures in infancy, a task complicated by rapid brain growth, poor tissue contrast, and motion artifacts in pediatric MRI. These challenges are further exacerbated in ultra-low-field (ULF, 0.064 T) MRI, which, despite its lower image quality, offers an affordable, portable, and sedation-free alternative for use in low-resource settings. In this work, we propose a domain randomization (DR) framework to bridge the

Designing oxide-supported noble-metal catalysts that deliver high activity with long operating cycle at low metal loadings remains a central challenge for renewable chemistry. Deactivation by sintering, surface poisoning, and irreversible restructuring often offsets the benefits of atom-efficient formulations, while regeneration protocols can further degrade structure-performance relationships. This thesis advances a surface-chemistry-led approach on commercial Al2O3 that couples (i) bottom-up dispersion im

• Efficient bonding and debonding of composite laminates and sandwich structures. • Primer enables on-demand thermal separation of thermoset composite layers. • Co-curing strategy for integrating the primer into high-performance composites. • Process windows were validated via thermo-mechanical characterization. • Assessed the primer effect on sandwich structures’ thermomechanical response. Disassembly of constituent layers in composite laminates remains a major challenge in repair and end-of-life recycling

Electron magnetic circular dichroism (EMCD) in transmission electron microscopy (TEM) enables element-specific measurement of spin and orbital magnetic moments, analogous to x-ray magnetic circular dichroism (XMCD). While the EMCD technique offers unmatched spatial resolution, its quantitative accuracy remains under scrutiny, particularly in beam-splitter geometries with convergent probes. Here, we systematically evaluate the limits of quantitative EMCD analysis using the first-order magnetostructural trans

The destructive impact of the construction industry on the planet and its inhabitants is no longer in question. Global warming, waste management, depletion of natural resources, air and soil pollution are all issues that must be urgently addressed. They are also challenging the current economy, whose growth is directly correlated to the extraction of raw materials, the manufacture of new products and, ultimately, to their increased consumption. Besides, the constant transformation of the built environment a

Seismic risk analysis, at large scale and local scale, is fundamental support for mitigating the investment costs and recovery works, impacting society's economy. The presented article's main purpose is to present a mechanicalbased model to evaluate the fragility curves through nonlinear static analysis. The results achieved from statistical analysis allows defining a representative building stock for two height classes. Material properties for typical masonry typologies that characterise the unreinforced m

We investigated the magnetic properties of individual Ho atoms adsorbed on the (111) surface of Pt, which have been recently claimed to display single ion magnetic behavior. By combining x-ray absorption spectroscopy and magnetic dichroism measurements with ligand field multiplet calculations, we reveal a ground state which is incompatible with long spin relaxation times, in disagreement with former findings. A comparative study of the ground state and magnetic anisotropy of Ho and Er on Pt(111) and Cu(111)

We show that the formation of a gel by conducting colloidal particles leads to a dramatic enhancement in bulk conductivity, due to interparticle electron tunneling, combining predictions from molecular-dynamics simulations with structural measurements in an experimental colloid system. Our results show how colloidal gelation can be used as a general route to huge enhancements of conductivity, and suggest a feasible way for developing cheap materials with novel properties and low metal content.

The development of new technologies to monitor drugs concentration directly in patient’s blood is absolutely required to succeed in personalized drug therapies. In this study, Etoposide - a well-known anti-cancer drug - has been chosen as model for cyclic voltammetry detection of drugs. Carbon nanotubes are chosen as electron-transfer mediators to enhance the system sensitivity. A very low frequency and low slope triangular-wave potential is required to acquire cyclic voltammograms. Cyclic voltammograms are

Electronic band gaps and dielectric constants are obtained for amorphous hafnium silicates using first-principles methods. Models of amorphous (HfO2)(x)(SiO2)(1-x) for varying x are generated by ab initio molecular dynamics. The calculations show that the presence of Hf gives rise to low-lying conduction states which explain the experimentally observed nonlinear dependence of the band gap on hafnium content. Static dielectric constants are found to depend linearly on x, supporting recent experimental data.

We compare defect energy levels of point defects in alpha-quartz using density functionals of different accuracy: a standard generalized-gradient-approximation functional and a hybrid functional. The latter is known to improve the description of band gaps through the incorporation of a fraction of Hartree-Fock exchange. The separations between the defect levels are found to be preserved when going from the standard to the more accurate hybrid functional, indicating that they are already well described with

Incorporation of nanoparticles into photostructurable polymer materials enables the engineering of novel, highly integrated micro/nanosystems (MEMS/NEMS) with enhanced intrinsic functional properties. For instance, nanoparticles with (semi)conducting, optical or magnetic properties can be incorporated into polymers in order to convey their inherent functionalities to the final material, which can then be exploited for sensor and actuator applications. The current challenge is two-fold: (a) the incorporation

This paper describes a new method to estimate the standstill position of Permanent Magnet Synchronous Motors (PMSM). The method is based on the anisotropic properties of permanent magnets and is therefore referred to as Magnetic Anisotropy Method (MAM). The MAM method differs significantly from all standard standstill position detection methods previously presented in the literature. The proposed method is totally independent of saliency and saturation effects and can therefore be used in many types of PMSM

Synthetic boron-doped diamond thin film is a new promising anode material. Because of its properties (high anodic stability under drastic conditions and wide potential window), it is widely investigated for numerous possible electrochemical applications such as electrosynthesis, preparation of powerful oxidants and electroincineration. In the first part of this work, simple charge transfer was investigated at boron-doped diamond electrode through the study of an outer sphere system in the potential region o

The spectroscopic and electrochemical properties of two-dimensional electrostatic assembly of Au nanocrystals are examined on poly-L-lysine (pLys) modified gold electrodes. The surface preparation for the nanoparticle deposition involved the self-assembly of a monolayer of 11-mercaptoundecanoic acid on the electrode surface, followed by the electrostatic deposition of pLys from aqueous solution. The polyelectrolyte layer acts as the electrostatic anchor for the Au particles. Electrostatically stabilised Au

Gold nanoparticles of 2–5 nm supported on woven fabrics of activated carbon fibers (ACF) were effective during CO oxidation at room temperature. To obtain a high metal dispersion, Au was deposited on ACF from aqueous solution of ethylenediamine complex [Au(en)2]Cl3 via ion exchange with protons of surface functional groups. The temperature-programmed decomposition method showed the presence of two main types of functional groups on the ACF surface: the first type was associated with carboxylic groups easily

Ultra-High Performance Fibre-Reinforced Concretes (UHPFRC) have high mechanical strengths (fU,c > 150 MPa, fU,t > 6 MPa) and exhibit quasi-strain hardening in tension. Their very low permeability prevents the ingress of detrimental substances. In composite structural elements formed of normal strength reinforced concrete and Advanced Cementitious Materials (ACM), UHPFRC offer a high potential in view of the load carrying and protection function of the ACM layer. The objectives of the study described in this

This thesis is concerned with the theoretical study of the adsorption of molecules and thin films to single-crystal metal surfaces. First-principles electronic calculations are performed in the framework of density functional theory in the local density approximation (LDA-DFT), by using a plane-wave formalism, norm-conserving pseudopotentials and the supercell method. For the calculation of the electronic ground state and the subsequent structural optimizations we use the Car-Parrinello technique, modified

Laser light is an invaluable tool for detailed experimental studies of chemical reactions. The ability to prepare reagent molecules in specific quantum states and to resolve the quantum state distribution of reaction products using laser radiation has been key to the field of chemical reaction dynamics, which studies chemistry at a fundamental microscopic level. Today, state-resolved experiments are common for unimolecular and bi-molecular reactions in the gas phase, but equivalent measurements for gas/surf

Compositional effects of rice husk based activated carbon on properties of steel waste derived magnetite nanoparticles

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Roadmap on advanced and / real-time characterisation of solid state materials and devices for energy applications

Segmenting Infant Brains Across Magnetic Fields: Domain Randomization and Annotation Curation in Ultra-low Field MRI

Surface Engineering of Oxide-Supported Catalysts for Renewable Chemistry

Design of debondable composite sandwich structures containing a primer based on thermally expandable microspheres: process window & thermomechanical performance evaluation

Sub-10-nm quantification of spin and orbital magnetic moment across the metamagnetic phase transition in FeRh using EMCD

Steel, a material to reuse

Fragility curves for special types of Switzerland buildings

Magnetism of Ho and Er Atoms on Close-Packed Metal Surfaces

Enhanced tunneling conductivity induced by gelation of attractive colloids

Nano-Sensor and Circuit Design for Anti-Cancer Drug Detection

Band gaps and dielectric constants of amorphous hafnium silicates: A first-principles investigation

Effect of improved band-gap description in density functional theory on defect energy levels in alpha-quartz

High-aspect ratio three-dimensional photoresin-based microstructures doped with luminescent nanocrystals

A new standstill position detection technique for non-salient PMSM's using the Magnetic Anisotropy Method (MAM)

Electrochemical oxygen transfer reaction on synthetic boron-doped diamond thin film electrode

Electrochemical and optical properties of two dimensional electrostatic assembly of Au nanocrystals

Highly dispersed gold on activated carbon fibers for low temperature CO oxidation

Structural behaviour of elements combining ultra-high performance fibre reinforced concretes (UHPFRC) and reinforced concrete

First-principles molecular-dynamics study of metal-supported nanosystems

Quantum state resolved studies of gas/surface reaction dynamics