335598 research outputs found
Sort by
Potential Energy Curves of Core-Excited States of the U M Absorption Edge Manifold of UO
No full textX-Ray Absorption Near Edge Structure of the U M X-ray absorption edge of UO is analyzed using the potential energy curves of an isolated UO obtained from rigorous, multiconfigurational all-electron ab initio, wavefunctions for the ground and core-excited configurations. The spectroscopic parameters for the potential energy curves are reported.
Two novel theoretical methods have been used as measures of the covalent character of the U-O bond:
(1) The projection of the U(5f) and U(6d) orbitals of the isolated U cation on the orbitals of the ground and the core-excited states of UO and
(2) the size of the orbital charge distributions given by the expectation values.
This gives direct insight into the variation of the electronic structure of the bond as the U-O bond length is changed. The excellent agreement of the simulated with the experimental U M XANES spectrum proves the validity of our theoretical model. The potential energy curves and the simulated XANES spectra for varying bond length together with the information from the two measures about the covalent character allow us to establish a link between X-ray spectroscopy and chemical bonding
„Ein ChatGPt fürs Klima“ – Das WOW-Forschungsprojekt entwickelt ein KI-Weltklimamodell am Karlsruher Institut für Technologie - Campus-Report am 17.02.2026
No full textKünstliche Intelligenz hat die traditionelle Wettervorhersage revolutioniert, ohne dass das in der breiteren Öffentlichkeit so richtig zu Kenntnis genommen wurde. In der Vorhersage bis zu 10 Tagen ist eine KI, die mit Jahrzehnten historischer Wetterdaten trainiert wurde, den traditionellen numerischen Modellen deutlich überlegen. So genannte numerische Modelle versuchen die tatsächlichen physikalischen und chemischen Prozesse im Wetter-geschehen abzubilden. Sie stoßen an ihre Grenzen, wenn es beispielsweise darum geht, genaue Vorhersagen für längere Zeiträume oder ein eng begrenztes Gebiet zu machen. Dabei verbrauchen sie schlicht zu viel Rechenpower. KI-Wettermodelle brauchen in ihrer Trainingsphase ebenfalls enorme Computerressourcen. Sind sie aber einmal etabliert, kommen sie mit Bruchteilen der Rechenleistung und Rechenzeit zurecht. In einem von der Carl-Zeiss-Stiftung geförderten Forschungsprojekt am Karlsruher Institut für Technologie sollen die Vorteile von KI-basierten Modellen jetzt auf das gesamte Klima-Wetter- und Umwelt Geschehen des Planeten angewandt werden. Mit WOW für „a World model of Our World“ soll das komplexe Zusammenspiel von Atmosphäre, Wasser und Landoberflächen einschließlich Starkregen, Dürren und Wolkenbildung mit einer weiterentwickelten KI räumlich hochaufgelöst und auf allen möglichen Zeit Skalen abgebildet werden. Die Hoffnung dabei: ein funktionierendes KI-Weltklimamodell ließe sich auch auf andere hochkomplexe Wissenschaftsgebiete wie beispielsweise die Kosmologie übertragen
Development & characterization of electrodes for large-scale Xenon Time Projection Chambers
No full textDual-phase liquid xenon time projection chambers are the core detector elements of many experiments that conduct searches for Dark Matter and rare events, as well as in neutrino and high-energy physics. As part of this detector technology, high-voltage electrodes are instrumental for the generation of observable signals and their physical interpretation. Thus, electrode design and manufacturing has to fulfill stringent requirements, and their production is associated with significant engineering challenges. In this work we describe the successful development of electrodes on the 1.5 m-scale, from their design and simulation to subsequent assembly and high-voltage testing in a gaseous argon environment. The produced electrodes were recently installed as an anode and a cathode during an upgrade to the XENONnT experiment
A mathematical analysis for spark ignition for premixed flame based on extended perfectly stirred reactor (PSR) model
No full textQBOi El Niño Southern Oscillation experiments: assessing relationships between ENSO, MJO, and QBO
No full textThis study uses an ensemble of climate model experiments coordinated by the Quasi-Biennial Oscillation initiative (QBOi) to analyze the Madden-Julian Oscillation (MJO) in the presence of either perpetual El Niño or La Niña sea surface temperatures during boreal winter. In addition to the prescribed El Niño Southern Oscillation (ENSO) conditions, the nine models internally generate QBOs, meaning each may influence the MJO. Objectives of our analyses are to assess the response of the MJO to strong idealized ENSO forcing and look for evidence of a QBO influence on the MJO in a multi-model context. The diagnostics used include wavenumber-frequency spectra of tropical convective and dynamical fields, measures of MJO lifetime, an evaluation of MJO diversity and visualization of MJO vertical structure, as well as an assessment of QBO morphology and the QBO\u27s impact on tropical convection. Kelvin wave spectral power increases in the El Niño simulations whereas equatorial Rossby waves power is stronger in the La Niña simulations. All models simulate faster MJO propagation under El Niño conditions. This change in speed is corroborated by the MJO diversity analysis, which reveals that models better reproduce the observed “fast propagating” and “standing” MJO archetypes given perpetual El Niño and La Niña, respectively. Regardless of ENSO, QBO descent into the lower stratosphere is underestimated and we detect little QBO influence on tropical tropopause stability and MJO activity. With little influence from the QBO on the MJO activity in these runs, we can be confident that the aforementioned changes in the MJO indeed arise from the different ENSO boundary conditions
Low-filled electrically conductive adhesives based on silver-coated glass and copper particles
No full textReplacing silver in solar module production is the hot topic in metallization and interconnection development. Whereas in metallization mainly silver-coated copper is utilized, the lower electrical requirements for cell interconnection, open up the opportunity to utilize particles with non-conductive cores as well. This study focuses on the development and characterization of an electrically conductive adhesive (ECA) for the shingled cell interconnection based on silver-coated glass and silver-coated copper particles, respectively. The formulated low-filled ECAs were stabilized against sedimentation using a halogen-based additive.
The silver-coated glass particles show good compatibility with the utilized epoxy resin. Employing a mixture of silver-coated glass particles and silver flakes, the silver content in the ECA can be reduced to 25 wt% and the mechanical properties can be adjusted by the fraction of glass particles used. In shingled modules such an ECA shows the same stable performance as the reference based on pure silver particles.
An ECA with only 7 wt% silver was formulated using silver-coated copper particles meeting all requirements for solar cell shingling. Shingled modules build from such an ECA show promising initial efficiency. Damp heat 500 was passed comparable to the silver reference, indicating oxidation stability. However, degradation during accelerated thermal cycling 200 is believed to originate from remaining issues with curing.
This study shows, that by carefully adjusting polymer, particles and additives the silver consumption in ECAs can be significantly reduced without any losses in interconnection performance
Blognotiz 25.01.2026: Trump, Grönland und die Medien: Eine Woche im Januar 2026
No full textDieser Blogbeitrag untersucht das Zusammenspiel zwischen Medienrummel, geopolitischen Dynamiken und akademischer Reflexion, wie es in einem Blogbeitrag vom 25. Januar 2026 dokumentiert ist. Der Autor beobachtet während seiner beruflichen Wiedereingliederung, wie die weltweite Aufmerksamkeit zwischen Grønland, dem Ukraine-Konflikt und den Iran-Protesten schwankt, die aus dem öffentlichen Diskurs weitgehend verschwunden sind. Der Beitrag hebt die Vergänglichkeit des Medieninteresses hervor, insbesondere in Bezug auf Grønland, das aufgrund politischer Rhetorik kurzzeitig internationales Interesse auf sich zog, aber schnell aus den Schlagzeilen verschwand. Der Autor reflektiert über das Vermächtnis von Entdeckern und Geografen wie Jean Malaurie und Christoph Jentsch, deren Arbeit eine ganze Generation von Geografen inspirierte, und stellt dies dem aktuellen Stand der deutschen akademischen Geografie gegenüber, in der solche explorativen Traditionen an Bedeutung verloren haben.
Darüber hinaus kritisiert der Beitrag die Auswirkungen der Trump-Regierung auf die US-Demokratie und äußert Bedenken hinsichtlich der Integrität der bevorstehenden Zwischenwahlen im November 2026. Der Autor weist auch auf einen breiteren gesellschaftlichen Trend in der Rhein-Neckar-Region hin, wo erfahrene Fachkräfte in den Vorruhestand gedrängt werden, was möglicherweise zu einem Verlust an kritischem Fachwissen führt. Auf persönlicher Ebene nimmt der Autor die Lehre eines geoökologischen Seminars wieder auf und knüpft damit an langjährige Forschungsinteressen wie die „Megaherbivore-Theorie” und die Dynamik von Waldbränden an, die wiederkehrende Themen in seiner akademischen Arbeit waren
Open-source data set for characterizing the charging behavior of electric vehicles
No full textThis data publication contains highly frequent measurements for 18 data sets of 16 electrical vehicles (EV) from 12 different manufacturers. It provides information about the charging, the electric vehicle, the charging behaviour and the environment temperature where the charging took place. The measurement data is provided both in low-frequency (LF) and high-frequency (HF) datasets. Each dataset represents an exact point of measurement. It is published with the paper "Open-source data set for characterizing the charging behavior of electric vehicles".
Charging overview and number of measurements
In total, 18 data sets of 16 electrical vehicles (EVs) from 12 manufacturers have been included. The measurements took place from October 28, 2025 to December 02, 2025. A detailed overview of the number of datasets can be obtained from the following table:
Date
Brand
Vehicle type
Number of lf measurements
Number of hf measurements
2025-10-28
Opel
Corsa Electric GS
1,331,504
34,760,000
2025-10-30
VW
e-Golf
1,197,329
125,710,000
2025-11-03
Dacia
Spring
767,515
75,207,650
2025-11-04
Audi
Q4 35 e-tron
1,442,506
151,463,150
2025-11-05
Renault
Zoe
1,396,852
146,670,000
2025-11-06
VW
iD.3
1,392,367
146,198,450
2025-11-07
Nissan
Leaf (ZE1)
1,177,937
123,709,430
2025-11-11
Tesla
Model 3
1,054,758
110,749,450
2025-11-13
MG
4 Luxury
4,296,133
451,093,950
2025-11-14
VW
e-Up!
1,182,875
124,201,900
2025-11-17
Opel
Mokka
1,610,711
186,990,000
2025-11-18
Mini
Cooper E
282,356
30,187,300
2025-11-20
Hyundai
Ioniq 5
2,042,800
239,355,000
2025-11-24
MG
4 Luxury
1,796,051
188,585,350
2025-11-26
KIA
EV6
1,366,135
143,444,200
2025-11-28
Hyundai
Inster
601,559
63,163,650
2025-12-01
KIA
EV6
615,483
64,625,650
2025-12-02
Smart
EQ fortwo
923,020
96,917,150
24,474,687
2,502,695,871
Data format
The data are provided in three formats:
CSV files with default comma-separated values, headers in the first line, uncompressed, and in UTF-8 format (*.csv) - due to the size of the dataset, we only provide a limited amount of data as CSV.
CSV files with default comma-separated values, headers in the first line, gz-compressed, and in UTF-8 format (*.csv.gz) - due to the size of the dataset, we only provide a limited amount of data as compressed CSV.
Apache Parquet files containing highly compressed time series data (*.parquet), equivalent to CSV files for importing into a Database such as DuckDB (recommended approach).
Data tables
The following tables are provided:
Charging overview
File: charging.csv, charging.parqet,
Contains a list of all charging data sets, referencing the date and the car.
Field Name
Format
Description
charging_uuid
String with UUID v4
The UUID of the charging data set, used as the primary key for identification in all other tables
date
date in YYYY-MM-DD format
The date on which the charging session took place
car_brand
String
The name of the brand of the EV
car_model
String
The name of the model of the EV
car_battery_size
Float (or NULL)
The size of the battery if known in kWh
Low-frequency (lf) EV charging data set
File: ev-charging_lf.csv.gz, ev-charging_lf.parquet
Description: Includes all low-frequency measurements of the cars that are involved in the data publication.
Field Name
Format
Unit
Description
charging_uuid
String with UUID v4
The UUID of the charging data set, more information can be obtained from the charging table.
timestamp_ns
Unsigned Integer
The UNIX timestamp in nanoseconds
u_l1_v
Float
V
The measured voltage of the first phase in V
u_l2_v
Float
V
The measured voltage of the second phase in V
u_l3_v
Float
V
The measured voltage of the third phase
i_l1_a
Float
A
The measured amperage of the first phase
i_l2_a
Float
A
The measured amperage of the second phase
i_l3_a
Float
A
The measured amperage of the third phase
p_l1_w
Float
W
The calculated performance of the first phase
p_l2_w
Float
W
The calculated performance of the second phase
p_l3_w
Float
W
The calculated performance of the third phase
q_l1_var
Float
Var
The calculated reactive power of the first phase
q_l2_var
Float
Var
The calculated reactive power of the second phase
q_l3_var
Float
Var
The calculated reactive power of the third phase
s_l1_va
Float
VA
The calculated apparent power of the first phase
s_l2_va
Float
VA
The calculated apparent power of the second phase
s_l3_va
Float
VA
The calculated apparent power of the third phase
phi_l1
Float
°
The calculated phase angle of the first phase
phi_l1
Float
°
The calculated phase angle of the second phase
phi_l1
Float
°
The calculated phase angle of the third phase
soc_percent
Float
%
The measured state of charge of the battery
setpoint_a
Float
A
The setpoint of the current timestamp
High-frequency (hf) EV charging data set
File: ev-charging_hf.parquet
Description: Includes all high-frequency measurements of the cars that are involved in the data publication.
Field name
Format
Unit
Description
charging_uuid
String with UUID v4
The UUID of the charging data set, more information can be obtained from the Charging table.
timestamp_ns
Unsigned Integer
The UNIX timestamp in nanoseconds
u_l1_v
Float
V
The measured voltage of the first phase in V
u_l2_v
Float
V
The measured voltage of the second phase in V
u_l3_v
Float
V
The measured voltage of the third phase
i_l1_a
Float
A
The measured amperage of the first phase
i_l2_a
Float
A
The measured amperage of the second phase
i_l3_a
Float
A
The measured amperage of the second phase
setpoint_a
Float
A
The setpoint of the current timestamp
Environment temperature
File: temperature.csv; temperature.parquet
Description: Contains the environment temperature next to the measuring location (KIT Campus Nord in Eggenstein-Leopoldshafen, Germany).
Field name
Format
Description
Time
Unix-Timestamp
The timestamp of the measurement time
Temperature
Float
The measured temperature in Celsius (°C
Wavelength-resolved heterodimer [2 + 2] photocycloadditions for reversible surface grafting
No full textWe report the first wavelength-dependent quantum yields of a [2 + 2] photocycloaddition generating the heterodimers of 7-hydroxycoumarin (7HCou) and styrene via a photochemical action plot. The wavelength-dependent heterodimer quantum yields are quantified at a constant number of photons at each wavelength between 310 and 370 nm. The resulting wavelength-dependent quantum yields demonstrate that the heterodimer is most efficiently generated at 345 nm, red-shifted by close to 25 nm compared to the absorption maximum of 7HCou at 320 nm. We subsequently translate these findings to photochemical surface functionalization by exploiting heterodimer formation between a surface bound coumarin derivative and para-styrene perfluoroalkyl ether (StyPFA) on surfaces under 345 nm irradiation to reversibly modulate surface hydrophobicity. The reversibility of the surface heterodimerization is demonstrated by removing StyPFA under UVC irradiation, and re-functionalization on the same surface. Functional heterodimer formation and the reversibility of the reaction on surface are followed via surface-sensitive X-ray photoelectron spectroscopy (XPS) and contact angle measurements. We subsequently apply our photochemical surface functionalization strategy to a dual cure photoresin based on a polyurethane-acrylate interpenetrating network, without deterioration of its mechanical properties, thereby confirming the feasibility of a photocycloaddition-based functionalization strategy for photoresins
Exploration and application of high entropy lithium argyrodites as solid electrolytes for all-solid-state batteries
No full textSolid-state batteries (SSBs) are a potentially safe, next-generation energy storage technology. Commercial viability of SSBs relies on the development of solid electrolytes with high ionic conductivity, high (electro)chemical stability, and good processability. A recent innovative approach to modify materials, potentially resulting in improved properties, is the “high-entropy” concept, characterized by ΔSconf > 1.5R (where ΔSconf and R represent the configurational entropy and ideal gas constant, respectively). However, the beneficial influence of a high configurational entropy on ion diffusion remains largely elusive given the absence of systematic studies. Therefore, this doctoral dissertation aimed to apply the high-entropy concept to solid electrolytes, in particular focusing on lithium argyrodites with the goal to achieve superionic conduction (~10 mS cm−1 at room temperature). The scientific objective was to understand the relationship between configurational entropy and charge-transport properties and to evaluate their potential as solid electrolytes for solid-state batteries.
The first part of this thesis mainly focuses on altering configurational entropy via composition of lithium argyrodites by multiple cation and anion substitutions, with the general formula Li6+x[M1aM2bM3cM4d]S5I (M = P, Si, Ge, and Sb) as well as Li5.5PS4.5ClxBr1.5−x. Both strategies enabled ionic conductivities of more than 10 mS cm−1 at room temperature, owing to increased configurational entropy, i.e., occupational disorder. Then, the second part of this work presents a detailed electrochemical performance evaluation of high-entropy lithium argyrodites and the commercially available lithium argyrodite Li6PS5Cl. The outcome shows that solely multi-anion substituted lithium argyrodites possess an enhanced electrochemical stability as compared to the reference solid electrolyte Li6PS5Cl and thus lead to an increased solid-state battery performance, especially at high current rates. In contrast, multi-cation substituted lithium argyrodite solid electrolytes suffer from poor oxidative stability and thus might only be applicable as separator layer in all-solid-state batteries. Altogether, our results indicate the possibility of improving ionic conductivity and electrochemical stability in ceramic ion conductors via entropy engineering, i.e., inducing complex substitution, overcoming compositional limitations for the design of advanced electrolytes and opening up new avenues in the fiel