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Cyclopentadienyl Complexes of Technetium
Get PDFThe number of structurally investigated cyclopentadienyl (Cp) complexes of technetium is limited in contrast to the situation with its heavier homolog, rhenium. Although this could be attributed to the radioactivity of all isotopes of the radioelement, there are also clear chemical differences to analogous compounds of the other group seven elements, manganese and rhenium. Technetium Cp compounds are known with the metal in the oxidation states “+1” to “+7”, with a clear dominance of Tc(I) carbonyls and nitrosyls. Corresponding carbonyl complexes also play a significant role in the development of Tc-based radiopharmaceuticals with the aromatic ring as an ideal position for the attachment of biomarkers. In this paper, the present status of the synthetic and structural chemistry of technetium with Cp ligands is discussed, together with recent developments in the corresponding Tc labeling chemistry
Interview with Alexander Benlian on the “Center Responsible Digitality” (ZEVEDI, www.zevedi.de)
Get PDFBoundary Value Problems for p-Adic Elliptic Parisi-Zúñiga Diffusion
Get PDFElliptic integral-differential operators resembling the classical elliptic partial differential equations are defined over a compact d-dimensional p-adic domain, together with associated Sobolev spaces relying on coordinate Vladimirov-type Laplacians dating back to an idea of Wilson Zúñiga-Galindo in his previous work. The associated Poisson equations under boundary conditions are solved and their L-spectra are determined. Under certain finiteness conditions, a Markov semigroup acting on the Sobolev spaces which are also Hilbert spaces can be associated with such an operator and the boundary condition. It is shown that this also has an explicitly given heat kernel as an L-function, which allows a Green function to be derived from it
A Taxonomy of Collusion in Information Systems
Get PDFCollusion poses a pervasive threat to information systems (IS), undermining fairness, trust, and system integrity. Existing research, however, often focuses narrowly on specific cases or emphasizes either social or technical aspects, resulting in fragmented insights and limited generalizability. This narrow scope hampers the development of broadly effective protection strategies. Recognizing collusion as a sociotechnical phenomenon shaped by the interplay between social actors and technical artifacts, we developed a case-agnostic taxonomy that helps uncover and classify various forms of collusion in IS. Using an iterative approach, we synthesized insights from multidisciplinary academic literature and descriptive legal cases. Grounded in general systems theory, the taxonomy offers a robust structural foundation for analyzing collusion in IS. This taxonomy benefits practice by capturing the structural characteristics of collusion, enabling more systematic analysis, detection, and mitigation
Development and application of a predictive fermentation model for continuous and pressurized fermentation using Clostridium ljungdahlii
No full textUtilization of CO-containing industrial waste gas emissions as substrates for fermentation with
acetogen bacteria is a novel approach. A key requirement for successful process optimization and the
development of advanced control strategies is a robust model that can sufficiently predict system
responses to varying process conditions. However, few fermentation models have been developed for
continuous cell retention or elevated pressure conditions, which are beneficial for integrating gas
fermentation with CO separation technologies. Therefore, this study adapts a dynamic kinetic model
to simulate these conditions to enable model-supported process design with Clostridium ljungdahlii.
The literature model was modified by adjusting key equations and re-estimating important kinetic
parameters derived from long-term fermentation experiments in a continuous stirred tank reactor.
Addition of a carbon dioxide dependency to the hydrogen uptake rate and the acetate to ethanol
conversion rate improves the model’s accuracy to predict biomass and product concentration trends
under high hydrogen substrate gas and moderately increased pressure conditions. Model predictions indicate that maximum ethanol production is linked with biomass growth and increases more than tenfold when the gas residence time is lowered from 1.80 to 0.09 h, and the H₂ content in the substrate gas is simultaneously raised from 60 to 80%, with the remainder being CO. Maximum acetate production is predicted to increase with lower gas residence time, 50% H₂ in the feedstock gas and a shift from CO to a mixture of CO and CO₂ as a carbon source, with a CO₂ content of up to 30%
Exploring outcome-driven policymaking on protected areas with an endogenous institutional model
No full textLISA: A Lithium-Ion Solid-State Assistant using large language models for knowledge defragmentation in battery science and beyond
No full textAssignment of Si-O vibrational modes in the IR spectra of C-S-H phases based on single-crystal polarized IR and Raman spectra of 14 A tobermorite, jennite, and jaffeite
No full textThis article explains the vibrational modes in the Si–O stretching range in the IR spectra of synthetic C-S-H phases with varying C/S ratios. These are compared with selected in situ spectra of hydrates of OPC, and those of synthetic crystalline hydrates. The assignments were supported by 29Si NMR and trimethylsilylation (TMS) data. IR and Raman polarized spectra of oriented crystals of 14 Å tobermorite, jennite and jaffeite enabled direct observation of the Si–O vibrational modes. They were successfully resolved based on the involvement of specific silicon (paired, bridging) and oxygen (bridging, non-bridging) atoms, and were compared with existing theoretical data. The resemblance between the IR spectra of synthetic C-S-H and those formed upon hydration of OPC, proves the suitability of model C-S-H phases for understanding hydration processes. Some uncertainties in the assignment of the C-S-H bands observed in existing in situ IR experiments are discussed, and potential sources of error identified
Characterization of the Regional Climate and Large‐Scale Atmospheric Circulation in the Caspian Sea Region During the Last Glacial Maximum
No full textThe Caspian Sea is the largest inland water body on Earth. Still, this region is often not considered
in paleoclimate model analyses. In this study, we examine the climate of the Caspian Sea region during the Last
Glacial Maximum (LGM) and its driving large‐scale atmospheric circulation using data from two global climate
models (AWI‐ESM‐1‐1LR and MPI‐ESM1.2‐LR) within the PMIP4 framework. We validate the simulation
output against proxy data, including information derived from pollen, lake sediments, and loess deposits. Our
results demonstrate that the global climate simulations align more closely with proxy data within the Caspian
Sea region (mostly within one standard deviation) than the Mediterranean and Western Europe and can thus be
further exploited. The subtropical jet stream is dominant in winter exhibiting higher wind speeds than in
summer, where the jet stream undergoes a transition from a zonal structure under preindustrial conditions to a
wave‐like pattern during the LGM. Furthermore, there is an increase in extratropical cyclone activity during the
LGM. The analysis of the near‐surface circulation reveals the dominance of an anticyclonic flow in summer,
which becomes even more frequent during the LGM (increase by up to 20%). The general characteristics of the
rotational circulation weather types change toward an intensification during the LGM. Overall, the models
demonstrate greater agreement at larger scales. However, to enable a more direct comparison with local proxy
data, especially in the topographically complex region along the southern coast of the Caspian Sea, we suggest a
follow‐up study employing high‐resolution climate simulations
