Gesellschaft für Elektrometallurgie (Germany)

The magnetic properties of electrical steel sheets, crucial for efficient electrical machine performance, deteriorate through manufacturing processes. This study investigates the impact of different manufacturing steps on magnetization behavior and specific core losses in M270-50A electrical steel, and their influence on the performance of a reluctance synchronous machine (RSM). Magnetic measurements were conducted on three material states: laser-cut strips, assembled stator cores, and press-fitted stator cores. These were integrated into finite element analysis (FEA) models, including an extended two-region stator model that separates yoke and tooth regions to reflect different manufacturing effects. Simulations examined torque characteristics and flux linkage under various loading conditions and were validated using a prototype machine. The findings of magnetic measurements indicate that manufacturing-induced stresses significantly increase magnetization demand and core losses—up to 650% and 53%, respectively. These effects lead to a 4.2% reduction in maximum air gap torque and notable changes in torque characteristic curves and d-axis flux linkage maps. Including realistic magnetic data yielded torque predictions closely aligned with experimental results and reduced discrepancy in core loss simulation by more than 50%. The study’s findings indicate that accounting for manufacturing influences in material characterization enhances modeling accuracy and enables optimized electrical machine designs and control strategies.

This paper uses a permanent reduction of the “tampon tax” in Germany to study the price and unit-sales effects of the tax. Exploiting an extensive data set on the sales and scanner prices of feminine hygiene products in Germany and Italy, our results show that the incidence of tampon taxes is fully on consumers, while demand for these products is price-inelastic. We do not find cross-price effects for a closely related product group, which remained taxed at the standard tax rate. We conclude that reducing taxes on feminine hygiene products could be an effective measure to address “period poverty”.

Objectives: The relationship between oral health and general health of geriatric in-hospital patients (GIH) who are poly-morbid and edentulous is currently unclear. This study determined the relationship between oral health and general health, and further implications and recommendations were derived. Methods: This retrospective cohort study included 81 GIH patients with impairment of oral state and masticatory function and need for immediate prosthetic treatment. The number of medical diagnoses, particularly main diagnoses of being hospitalized, comorbid diagnoses and the dental/oral state, were evaluated. Laboratory data of vitamin D3 and albumin concentrations were measured. Intraoral risk factors (IRF) affecting the masticatory function were intraoral inflammation, mucogingival impairment (MGI) and severe bone crest atrophy (SBCA). Masticatory function was evaluated by DMF*-T Index (number of destroyed/diseased, missing teeth and artificial fabrication), Eichner Index and Scores. The clinical relevance was surveyed by significance and effect size calculations. Results: In GIH, the number of medical diagnoses correlated significantly with the occurrence of IRFs. SBCA was the most affecting IRF, as measured by Eichner Index at baseline (p = 0.001). Single main diagnoses CNS and gastro-intestinal disease (GID) correlated with both deficiency of vitamin D3 levels (p = 0.011; p = 0.028) and hypoalbuminemia (p = 0.013; p = 0.023). Single comorbid diagnoses significantly correlated with both vitamin D3 deficiency and hypoalbuminemia (CVD (p = 0.031); DM (p = 0.042). Hypoalbuminemia was further found to be correlated with the sum of comorbid diagnoses (p = 0.033). Conclusions: GIH patients suffered from general and dental poly-morbidity. The prevalence of diseases was higher due to SBCA and impaired masticatory function. Deficiency of vitamin D3 and hypoalbuminemia were possible malnutrition markers.

Abstract: The development of Situational Judgment Tests (SJTs) is a multi-step procedure that often requires substantial resources and time. ChatGPT as a large language model has already proven helpful for many complex tasks, including the development of psychological questionnaires. However, ChatGPT has so far not been tested for its ability to develop SJT items, which could speed up SJT development and thus contribute to the dissemination of psychometrically well-designed SJTs in practice and also support research requiring specific SJTs or SJT versions. Thus, the current study ( N = 419) examined whether ChatGPT (2023, Feb 13 version using ChatGPT-3.5) can create SJT items, assessing a facet of personality (i.e., gregariousness), that show similar psychometric properties (examined through confirmatory factor, reliability, and correlational analyses) as human-created SJT items. Results revealed that the measurement model for all eleven SJT items that were created by ChatGPT showed a poor model fit, while a reduced set of eight items yielded an acceptable fit. Reliability estimates as well as convergent and discriminant validity evidence were similar for the human-created and the ChatGPT-created SJT. Implications as well as potential boundary conditions of SJT development through ChatGPT are discussed.

This paper illustrates the influence of compressive stresses up to – 175 MPa on the specific core losses and magnetization demand of electrical steel sheets and press-fitted stator cores. Therefore, the press fit of a real motor geometry is designed and the mechanical stresses occurring were calculated numerically at ambient and operating temperature. Furthermore, measurements are done with a single sheet tester under compressive stresses and press fitted stator cores as ring probes. Tests are done with electrical steel sheets made of M270-50A grade at different frequencies, taking into account applications for industrial drives. With rising compressive stress, magnetization demand rises clearly in medium polarization range up to 1500 % at −175 MPa compared to stress-free condition. Specific core losses increase continuously with rising compressive stress, and real geometry stator core results can partially be directly compared to strip probes under compressive stress. For specific core losses a loss separation is done by the Bertotti approach, separating specific hysteresis, specific eddy current and specific excess losses. The results get prepared to be used in modified finite element analysis (FEA) calculations of an electrical machine, taking into account the manufacturing step of press fitting.

We humans sort the world around us into conceptual groups, such as 'the same' or 'different', which facilitates many cognitive tasks. Applying such abstract concepts can improve problem-solving success and is therefore worth the cognitive investment. In this study, we investigated whether ants (Lasius niger) can learn the relational rule of 'the same' or 'different' by training them in an odour match-to-sample test over 48 visits. While ants in the 'different' treatment improved significantly over time, reaching around 65% correct decisions, ants in the 'same' treatment did not. Ants did not seem able to learn such abstract relational concepts, but instead created their own individual strategy to try to solve the problem: some ants decided to 'always go left', others preferred a 'go to the more salient cue' heuristic which systematically biased their decisions. These heuristics even occasionally lowered the success rate in the experiment below chance, indicating that following any rule may be more desirable then making truly random decisions. As the finding that ants resort to heuristics when facing hard-to-solve decisions was discovered post-hoc, we strongly encourage other researchers to ask whether employing heuristics in the face of challenging tasks is a widespread phenomenon in insects.

The article contains sections titled:1.History2.Properties3.Occurrence4.Processing of the Raw Materials to Vanadium Compounds4.1.Iron Ores and Titanomagnetites as Raw Materials4.2.Processing of Other Raw Materials5.Production of Vanadium, Ferrovanadium, and Other Alloys5.1.Reduction Behavior of Vanadium Oxides5.2.Production of Vanadium Metal and its Alloys5.3.Ferrovanadium5.3.1.Production from Vanadium Oxides5.3.2.Direct Production from Slags and Residues5.4.Production of Other Vanadium Master Alloys6.Uses7.Vanadium Compounds8.Analysis9.Economic Aspects10.Environmental Protection and Toxicology

Simulation of ion beam extraction from an Electron Cyclotron Resonance Ion Source (ECRIS) is a fully 3 dimensional problem, even if the extraction geometry has cylindrical symmetry. Because of the strong magnetic flux density, not only the electrons are magnetized but also the Larmor radius of ions is much smaller than the geometrical dimension of the plasma chamber (Ø 64 × 179 mm). If we assume that the influence of collisions is small on the path of particles, we can do particle tracking through the plasma if the initial coordinates of particles are known. We generated starting coordinates of plasma ions by simulation of the plasma electrons, accelerated stochastically by the 14.5 GHz radio frequency power fed to the plasma. With that we were able to investigate the influence of different electron energies on the extracted beam. Using these assumptions, we can reproduce the experimental results obtained 10 years ago, where we monitored the beam profile with the help of viewing targets. Additionally, methods have been developed to investigate arbitrary 2D cuts of the 6D phase space. To this date, we are able to discuss full 4D information. Currently, we extend our analysis tool towards 5D and 6D, respectively.