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Sustainable resilient recycling partner selection for urban waste management: Consolidating perspectives of decision-makers and experts
No full textIn sustainable waste supply chains, selecting recycling partners is an important factor in the decision-making process. Waste supply chains have undergone many fundamental modifications because of the rise of concepts such as sustainability, circular economy, and resilience. To overcome the current shortcomings of the literature on recycling partner selection only based on sustainability aspects, an evaluation framework is developed to address recycling partner selection by considering both sustainability and resilience factors. Although developing a sustainable and resilient evaluation framework improves the process of selecting recycling partners, the problem becomes very complex, and multidimensional decision-makers require reliable and accurate tools to make informed decisions. Multi-criteria decision-making (MCDM) methods are useful decision-making tools with high reliability to address problems under uncertainty. Although previous studies have developed several MCDM methods based on various uncertainty sets, the capability to support efficient and accurate group decision-making by decision-makers’ opinions and experts’ judgments has been a major disadvantage. Therefore, this study develops a novel decision-making approach using Z-numbers based on the best-worst method (Z-BWM) and a combined compromise solution (Z-CoCoSo). The proposed novel approach for addressing a sustainability and resilience management problem in an urban setting is demonstrated in a real-life case study using Tabriz, Iran as a case study. According to the results, net profit and the robustness of the waste supply chain are the most important criteria
Effects of ball milling on biochar adsorption of contaminants in water: A meta-analysis
No full textReckless release of contaminants into the environment causes pollution in various aquatic systems on a global scale.Biochar is potentially an inexpensive and environmentally friendly adsorbent for removing contaminants fromwater. Ball milling has been used to enhance biochar's functionality; however, global analysis of the effect of ball millingon biochar's capacity to adsorb contaminants in aqueous solutions has not yet been done. Here, we conducted ameta-analysis to investigate the effects of ball milling on the adsorption/removal capacity of biochar for contaminantsin aqueous solutions, and to investigate whether ball milling effects are related to biochar production, ball milling, andother experimental variables. Overall, ball milling significantly increased biochar adsorption capacity towards both inorganicand organic contaminants, by 69.9%and 561.9%, respectively. This could be attributed to ball milling increasingbiochar surface area by 2.05-fold, pore volume by 2.39-fold, and decreasing biochar pH by 0.83-fold. The positiveadsorption effects induced by ball milling varied widely, with the most effective being ball milling for 12 to 24 h at 30
Improved Charge Carrier Transport Across Grain Boundaries in N‐type PbSe by Dopant Segregation
No full textAb initio investigation of topological magnetism in two-dimensional van der Waals heterostructures
No full textMagnetism in two-dimensional (2D) van der Walls (vdW) materials is a rapidly evolving field in condensed matter physics and materials science, marked by intriguing discoveries and potential applications. Unlike traditional three-dimensional materials, 2D vdW materials are characterized by their ultra-thin, often single-layer, structure leading to unique magnetic properties triggered by proximity-effects, which are facilitated by the underlying vdW gap. Such properties are not only fundamental for understanding the physics of low-dimensional systems but also hold immense promise for the development of advanced technologies in data storage, spintronics, and quantum computing. Building on the foundational understanding of magnetism in 2D materials, this thesis dives deeper into the specific case of CrTe2 and CrSBr. Based on a multiscale modelling approach that combines first-principles calculations and a Heisenberg model supplied with ab-initio parameters, we report a strong magnetoelastic coupling in a free-standing monolayer of CrTe2. We demonstrate that different crystal structures of a single CrTe2 give rise to non-collinear magnetism through magnetic frustration and the emergence of the Dzyaloshinskii-Moriya interaction (DMI). Utilizing atomistic spin relaxation, we perform a detailed investigation of the complex magnetic properties pertaining to this 2D material impacted by the presence of various types of structural distortions akin to charge density waves. Also, we demonstrate that interfacing a CrTe2 layer with various Te-based layers enables the control of the magnetic exchange and Dzyaloshinskii-Moriya interactions as well as the magnetic anisotropy energy of the whole heterobilayer, and thereby the emergence of topological magnetic phases such as skyrmions and antiferromagnetic N´eel merons. The latter are novel particles in the world of topological magnetism since they arise in a frustrated N´eel magnetic environment and manifest as multiples of intertwined hexamer-textures. Our findings pave a promising road for proximity-induced engineering of both ferromagnetic and long-sought antiferromagnetic chiral objects in the very same 2D material, which is appealing for new information technology devices employing quantum materials. Moreover, we demonstrate the all-electric switching of the topological nature of individual magnetic objects emerging in 2D vdW heterobilayers. We show that an external electric field modifies the vdW gap between CrTe2 and (Rh, Ti)Te2 layers and alters the underlying magnetic interactions. This enables switching between ferromagnetic skyrmions and meron pairs in the CrTe2/RhTe2 heterobilayer while it enhances the stability of frustrated antiferromagnetic merons in the CrTe2/TiTe2 heterobilayer. We envision that the electrical engineering of distinct topological magnetic solitons in a single device could pave the way for novel energy-efficient mechanisms to store and transmit information with applications in spintronics. Finally, via machine learning concepts we integrated linear spin wave theory (LSWT) with activelearning sampling to develop a Kalman Filter Adversarial Bayesian Optimization (KFABO) algorithm. This algorithm excels at managing highly noisy experimental spectra of 2D bulk CrSBr, aiming to map the experimentally extracted magnon spectrum with minimal sampling points and iterations. Additionally, the KFABO algorithm is designed to accurately extract magnetic parameters from inelastic neutron scattering data, significantly enhancing the efficiency and accuracy of experimental measurements
Further development of a Lamb-shift polarimeter
No full textThe Lamb-shift polarimeter (LSP) is a useful detection apparatus to verify nuclear spin polarizationfor atoms, molecules and ions consisting of hydrogen and/or its isotopes. Its functionality relieson the creation of metastable hydrogen atoms via a charge exchange reaction that preserves thenuclear polarization in a strong magnetic field. The nuclear polarization is then determinedby analyzing the relative occupation numbers between different metastable hyperfine states withdifferent nuclear spin projection . This makes the LSP a very rapid and cost efficient detectionmethod for beams with a beam energy in the keV range as no pre-acceleration is needed. In thepast it was shown that many of the above mentioned candidates like , , etc. could bemeasured with success, and in this work an additional ion, i.e. , adds up to the list. Furthermore,the measurements of polarized ions have been performed for pulsed beams as it was in usefor long times at the cooler synchrotron COSY in Jülich. In the second part, a theoretical outlookfor possible adaptations to the spin filter is given, which is an important component of the LSP.This paves the way to realize experiments investigating the bound beta decay or parity violation inmetastable hydrogen atoms. In addition, a short outlook for possible applications of beamsis given
Dynamic Analysis of the Effect of the Device-to-Device Variability of Real-World Memristors on the Implementation of Uncoupled Memristive Cellular Nonlinear Networks
No full textCoherent and non-unitary errors in ZZ-generated gates
No full textVariational algorithms such as the quantum approximate optimization algorithm have attracted attention due to their potential for solving problems using near-term quantum computers. The ZZ interaction typically generates the primitive two-qubit gate in such algorithms applied for a time, typically a variational parameter, γ. Different compilation techniques exist with respect to the implementation of two-qubit gates. Due to the importance of the ZZ-gate, we present an error analysis comparing the continuous-angle controlled phase gate (CP) against the fixed angle controlled Z-gate (CZ). We analyze both techniques under the influence of coherent over-rotation and depolarizing noise. We show that CP and CZ compilation techniques achieve comparable ZZ-gate fidelities if the incoherent error is below 0.03% and the coherent error is below 0.8%. Thus, we argue that for small coherent and incoherent error a non-parameterized two-qubit gate such as CZ in combination with virtual Z decomposition for single-qubit gates could lead to a significant reduction in the calibration required and, therefore, a less error-prone quantum device. We show that above a coherent error of 0.04π (2%), the CZ gate fidelity depends significantly on γ
A Rhizobox-Study Elucidating Biogas-Digestate Fertilization and Soil Compaction Effects on Juvenile Maize Growth and Rhizosphere pH
No full textBiogas digestate (BD) contains nitrogen (N), phosphorus (P), and potassium (K) and is easily and largely available in Germany and other countries in Europe. Nevertheless, few studies compare BD to mineral NPK fertilizer, particularly under soil compaction. The characteristics of these fertilizers and soil compaction may affect rhizosphere pH and root development, thereby affecting nutrient uptake by plants. This 18-day rhizobox study evaluated initial maize growth and root architecture responses to BD (derived from maize silage+chicken manure), mineral NPK, and BD + NPK fertilization under compacted (0–25 cm compacted; 25–55 cm loose) and loose (0–55 cm) substrates. Treatments promoted similar shoot biomass, specific leaf area, and sufficient shoot N, P, and K nutrition. Shoot P content in BD + NPK and NPK was 29–33% higher compared to BD. Root P content in NPK was 26% higher than in BD, independent of compaction, likely favoring root proliferation and explaining the higher root:shoot ratio in NPK. In loose soil, the main root length in NPK was 49% higher compared to BD, but rooting was deeper in BD. Rhizosphere alkalinization measured non-invasively suggested preferential maize N absorption as nitrate. Combining BD with fast-soluble P sources may provide maize performance comparable to mineral NPK
Understanding SOEC Performance and Degradation:A Multiphysics Approach for Experiment-driven Finite-Element-Modeling
No full textThis talk, given at the IET-1 Spring Seminar 2025, discusses a multiphysics approach to modeling Solid Oxide Electrolysis Cells (SOECs), focusing on integrating experimental data with simulation results to better understand performance and degradation mechanisms. A brief overview over the used model is provided and the results of the model's benchmarking and optimization procedure are communicated and discussed. Results highlight the potential for accurately modeling SOEC behavior and but also show potential for further refinement to extedn the model into a platform to predict performance and guide material development