Extern
Refine
Year of publication
- 2023 (55) (remove)
Document Type
- Article (25)
- Doctoral Thesis (17)
- Working Paper (6)
- Review (5)
- Bachelor Thesis (1)
- Master's Thesis (1)
Language
- English (55) (remove)
Keywords
- Diversity (2)
- Virus (2)
- cosmic rays (2)
- kosmische Strahlung (2)
- virus (2)
- 5-methoxycarbonylmethyl-2-thiouridine (1)
- AC Elektrokinetik (1)
- AC Elektroosmosis (1)
- AC electrokinetics (1)
- AC electroosmosis (1)
- Altiplano (1)
- Anden (1)
- Andes (1)
- Antikörper (1)
- Arctic aerosol (1)
- Arctic haze (1)
- Assemblierungsfaktor (1)
- Bachelor (1)
- Bindungsinteraktion (1)
- Biogenese (1)
- Biomoleküle (1)
- Bioraffinerie (1)
- Bodenunruhe (1)
- Bruchmodel (1)
- Bulge (1)
- Caco-2 (1)
- Carbon Capture (1)
- Carbon Dioxide Removal (1)
- Citrazinsäure (1)
- Climate Policy (1)
- Clustering (1)
- Course development (1)
- Course marketing (1)
- Courses for female students (1)
- Cu doped InP (1)
- Cu-dotiertes InP (1)
- Curricula Development (1)
- Curriculum analysis (1)
- DAS (1)
- Deformation (1)
- Deoxyfructosazin (1)
- Dielektrophorese (1)
- Einzelatomkatalyse (1)
- Emulsion (1)
- English and Physics teacher trainees (1)
- Ethics (1)
- Etna (1)
- Fernerkundung (1)
- Flache Subduktion (1)
- Flat subduction (1)
- Foreland (1)
- Galaxie: allgemein (1)
- Galaxien (1)
- Galaxienhaufen (1)
- Gender (1)
- Geodynamics (1)
- Geodynamik (1)
- Geschwindigkeitsmodell (1)
- Grüne Chemie (1)
- Gyrochronologie (1)
- H/V (1)
- H2S biosynthesis (1)
- HVSR (1)
- HepG2 (1)
- High growth firms (1)
- Immunoassay (1)
- Impermanence (1)
- Influenza (1)
- Informatics (1)
- Intersectionality (1)
- Inversion (1)
- Kohlenstoffnitriden (1)
- LOC (1)
- Li-Ionen-Kondensator (1)
- Li-ion capacitor (1)
- Lidar (1)
- Lyman-Alpha-Emitter (1)
- Lyman-alpha emitters (1)
- MSPAC (1)
- Magnetohydrodynamik (1)
- Mikrofluidik (1)
- Mikrokapseln (1)
- Mikrowellensynthese (1)
- Mikrozonierung (1)
- Moco biosynthesis (1)
- N400 (1)
- Nanoelektroden (1)
- Oberflächenchemie (1)
- Orogen (1)
- Ortscharakterisierung (1)
- Ortseffekte (1)
- PBCEC (1)
- POC (1)
- Photosynthese (1)
- Photosystem I (1)
- Piano delle Concazze (1)
- Pipistrellus nathusii (1)
- Polymernetzwerk (1)
- Puna (1)
- QD device (1)
- QD stability (1)
- QD-Gerät (1)
- QD-Stabilität (1)
- Quality of regional governments (1)
- Regions (1)
- Regulation (1)
- Repetition (1)
- Rezeptor (1)
- Rotation (1)
- SEPE Factors (1)
- SEPS factors (1)
- SPAC (1)
- STEM (1)
- Salzschmelze-Templating (1)
- Scheibe (1)
- Seismologie (1)
- Selen (1)
- Selenonein (1)
- Shortening (1)
- Sierras Pampeanas (1)
- Social Cost of Carbon (1)
- Social impact (1)
- Sociotechnical Design (1)
- St. Nicolas House Analysis (1)
- Statistical Exercise (1)
- Statistik (1)
- Sterne: Entfernungen (1)
- Stimuli-Sensitivität (1)
- Subduction (1)
- Subduktion (1)
- Summer Schools (1)
- Tektonik (1)
- Thylakoidmembran (1)
- Verkürzung (1)
- Vorland (1)
- Women and IT (1)
- achilles tendinopathy (1)
- acoustic communication (1)
- active galactic nuclei (1)
- aerosol: hygroscopic growth (1)
- aerosol: hygroskopisches Wachstum (1)
- aerosol: optical properties (1)
- aerosol: optische Eigenschaften (1)
- aktive Galaxienkerne (1)
- ambient vibration (1)
- animal migration (1)
- anterior PNP (1)
- antibody (1)
- arktischer Dunst (1)
- arktisches Aerosol (1)
- assembly factor (1)
- athletes (1)
- bats (1)
- binding interactions (1)
- biogenesis (1)
- biomechanics (1)
- biomolecule (1)
- biorefinery (1)
- body proportions (1)
- bulge (1)
- capabilities (1)
- carbon nitrides (1)
- catch-up-growth (1)
- cellular bioenergetics (1)
- changepoint analysis (1)
- changepoint detection (1)
- child growth (1)
- citrazinic acid (1)
- clustering (1)
- colloidal quantum dot (1)
- complex emulsion (1)
- constraint (1)
- cytosolic tRNA thiolation (1)
- decomposition (1)
- deep eutectic solvents (1)
- deoxyfructosazine (1)
- depressive disorder (1)
- design thinking (1)
- dielectrophoresis (1)
- digital technologies (1)
- digital transformation (1)
- disc (1)
- eavesdropping (1)
- echolocation (1)
- education (1)
- electromyography (1)
- elf-determination theory (1)
- emotional regulation (1)
- emulsion (1)
- entropy (1)
- expandierbar (1)
- expansion (1)
- food access (1)
- frustration (1)
- fundamental parameters (1)
- fundamentale Parameter (1)
- galaxies (1)
- galaxy clusters (1)
- galaxy: general (1)
- gemeinsame Inversion (1)
- green chemistry (1)
- großräumige Struktur des Universums (1)
- gyrochronology (1)
- height in history (1)
- heteroatom-doped carbons (1)
- heteroatom-dotierte Kohlenstoffe (1)
- heterogene Katalyse (1)
- heterogene Photokatalyse (1)
- heterogeneous catalysis (1)
- heterogeneous photocatalysis (1)
- high-redshift (1)
- hoher Rotverschiebung (1)
- horizontal-vertikales Spektralverhältnis (1)
- immunoassay (1)
- inequality (1)
- inequality of opportunity (1)
- influenza (1)
- intracluster medium (1)
- inversion (1)
- joint inversion (1)
- kinematics (1)
- kinetics (1)
- kolloidaler Quantenpunkt (1)
- komplexe Emulsion (1)
- lab-on-chip (1)
- large-scale structure (1)
- lösungsmittelfreie Synthese (1)
- magnetohydrodynamics (1)
- malnutrition (1)
- microcapsules (1)
- microfluidics (1)
- microwave synthesis (1)
- microzonation (1)
- migration (1)
- mini growth spurt (1)
- mixed methods (1)
- modifizierte räumliche Autkorrelationsmethode (1)
- multiresponsiv (1)
- multiresponsive (1)
- nanoelectrodes (1)
- neuromuscular (1)
- numerical astrophysics (1)
- numerische Astrophysik (1)
- nutrition (1)
- organic synthesis (1)
- organische Synthese (1)
- ortsverteile faseroptische Dehnungsmessung (1)
- pace of life (1)
- performance evaluation (1)
- phonotaxis (1)
- photosynthesis (1)
- photosystem I (1)
- physical fitness (1)
- physical time (1)
- playback (1)
- point-of-care (1)
- polymer network (1)
- porous materials (1)
- poröse Materialien (1)
- posterior P600 (1)
- predictability (1)
- probabilistic processing (1)
- psychopathology (1)
- pubertal timing (1)
- public health (1)
- receptor (1)
- reflective breadth (1)
- reflective depth (1)
- reflective skills (1)
- remote sensing (1)
- response styles theory (1)
- rotation (1)
- rumination (1)
- runners (1)
- räumliche Autkorrelationsmethode (1)
- räumliche Autokorrelation (1)
- salt melt templating (1)
- secular changes (1)
- seismic noise (1)
- seismisches Rauschen (1)
- seismology (1)
- selenium (1)
- selenoneine (1)
- short-term growth (1)
- single-atom catalysis (1)
- site characterization (1)
- site effects (1)
- skills (1)
- social network (1)
- socioeconomy (1)
- solvent-free reactions (1)
- source model (1)
- spatial autocorrelation (1)
- spindown (1)
- stark eutektisches Lösungsmittel (1)
- stars: distances (1)
- statistics (1)
- stellar content (1)
- stellarer Inhalt (1)
- stimuli-sensitivity (1)
- stunting (1)
- sulfite oxidase (1)
- surface chemistry (1)
- switchSENSE (1)
- switchSENSE Technologie (1)
- tectonics (1)
- thylakoid membranes (1)
- velocity model (1)
- volcanic tremor (1)
- vulkanischer Tremor (1)
- wealth (1)
- Ätna (1)
Institute
- Extern (55)
- Vereinigung für Jüdische Studien e. V. (12)
- Institut für Biochemie und Biologie (10)
- Institut für Physik und Astronomie (7)
- Institut für Chemie (6)
- Institut für Geowissenschaften (4)
- Center for Economic Policy Analysis (CEPA) (3)
- Fachgruppe Volkswirtschaftslehre (2)
- MenschenRechtsZentrum (2)
- Strukturbereich Kognitionswissenschaften (2)
Earthquake modeling is the key to a profound understanding of a rupture. Its kinematics or dynamics are derived from advanced rupture models that allow, for example, to reconstruct the direction and velocity of the rupture front or the evolving slip distribution behind the rupture front. Such models are often parameterized by a lattice of interacting sub-faults with many degrees of freedom, where, for example, the time history of the slip and rake on each sub-fault are inverted. To avoid overfitting or other numerical instabilities during a finite-fault estimation, most models are stabilized by geometric rather than physical constraints such as smoothing.
As a basis for the inversion approach of this study, we build on a new pseudo-dynamic rupture model (PDR) with only a few free parameters and a simple geometry as a physics-based solution of an earthquake rupture. The PDR derives the instantaneous slip from a given stress drop on the fault plane, with boundary conditions on the developing crack surface guaranteed at all times via a boundary element approach. As a side product, the source time function on each point on the rupture plane is not constraint and develops by itself without additional parametrization. The code was made publicly available as part of the Pyrocko and Grond Python packages. The approach was compared with conventional modeling for different earthquakes. For example, for the Mw 7.1 2016 Kumamoto, Japan, earthquake, the effects of geometric changes in the rupture surface on the slip and slip rate distributions could be reproduced by simply projecting stress vectors. For the Mw 7.5 2018 Palu, Indonesia, strike-slip earthquake, we also modelled rupture propagation using the 2D Eikonal equation and assuming a linear relationship between rupture and shear wave velocity. This allowed us to give a deeper and faster propagating rupture front and the resulting upward refraction as a new possible explanation for the apparent supershear observed at the Earth's surface.
The thesis investigates three aspects of earthquake inversion using PDR: (1) to test whether implementing a simplified rupture model with few parameters into a probabilistic Bayesian scheme without constraining geometric parameters is feasible, and whether this leads to fast and robust results that can be used for subsequent fast information systems (e.g., ground motion predictions). (2) To investigate whether combining broadband and strong-motion seismic records together with near-field ground deformation data improves the reliability of estimated rupture models in a Bayesian inversion. (3) To investigate whether a complex rupture can be represented by the inversion of multiple PDR sources and for what type of earthquakes this is recommended.
I developed the PDR inversion approach and applied the joint data inversions to two seismic sequences in different tectonic settings. Using multiple frequency bands and a multiple source inversion approach, I captured the multi-modal behaviour of the Mw 8.2 2021 South Sandwich subduction earthquake with a large, curved and slow rupturing shallow earthquake bounded by two faster and deeper smaller events. I could cross-validate the results with other methods, i.e., P-wave energy back-projection, a clustering analysis of aftershocks and a simple tsunami forward model.
The joint analysis of ground deformation and seismic data within a multiple source inversion also shed light on an earthquake triplet, which occurred in July 2022 in SE Iran. From the inversion and aftershock relocalization, I found indications for a vertical separation between the shallower mainshocks within the sedimentary cover and deeper aftershocks at the sediment-basement interface. The vertical offset could be caused by the ductile response of the evident salt layer to stress perturbations from the mainshocks.
The applications highlight the versatility of the simple PDR in probabilistic seismic source inversion capturing features of rather different, complex earthquakes. Limitations, as the evident focus on the major slip patches of the rupture are discussed as well as differences to other finite fault modeling methods.
Properties of Arctic aerosol in the transition between Arctic haze to summer season derived by lidar
(2023)
During the Arctic haze period, the Arctic troposphere consists of larger, yet fewer, aerosol particles than during the summer (Tunved et al., 2013; Quinn et al., 2007). Interannual variability (Graßl and Ritter, 2019; Rinke et al., 2004), as well as unknown origins (Stock et al., 2014) and properties of aerosol complicate modeling these annual aerosol cycles. This thesis investigates the modification of the microphysical properties of Arctic aerosols in the transition from Arctic haze to the summer season. Therefore, lidar measurements of Ny-Ålesund from April 2021 to the end of July 2021 are evaluated based on the aerosols’ optical properties. An overview of those properties will be provided. Furthermore, parallel radiosonde data is considered for indication of hygroscopic growth.
The annual aerosol cycle in 2021 differs from expectations based on previous studies from Tunved et al. (2013) and Quinn et al. (2007). Developments of backscatter, extinction, aerosol depolarisation, lidar ratio and color ratio show a return of the Arctic haze in May. The haze had already reduced in April, but regrew afterwards.
The average Arctic aerosol displays hygroscopic behaviour, meaning growth due to water uptake. To determine such a behaviour is generally laborious because various meteorological circumstances need to be considered. Two case studies provide further information on these possible events. In particular, a day with a rare ice cloud and with highly variable water cloud layers is observed.
Supporting reflection in preservice during university-based training is, without doubt, a crucial aspect in attaining teacher professionalism. Therefore, an on-campus seminar designed to relate theory to practice and vice versa – the so-called ‘Lehr-Lern-Labor-Seminar (LLLS)’ – was implemented over the course of five terms to stimulate reflective skills of English and Physics teacher trainees. Investigations on the effectiveness of three types of the LLLS (no video and two types of video-supported reflections) compared to a parallel group (PG) and a control group (CG) occurred in a mixed methods quasi-experimental study. Reflective skills were elicited with vignettes, relevant covariates with questionnaires. Reflective development was then traced in the dimensions depth and breadth employing a qualitative content analysis. MANCOVA (Multivariate Analysis of Covariance) and regression analyses revealed a substantive increase of reflective depth for English and Physics teacher trainees and breadth development for English LLLS-participants in contrast to both, a PG and a CG, even when controlling for the subjects’ individual prerequisites.
In the present thesis, AC electrokinetic forces, like dielectrophoresis and AC electroosmosis, were demonstrated as a simple and fast method to functionalize the surface of nanoelectrodes with submicrometer sized biological objects. These nanoelectrodes have a cylindrical shape with a diameter of 500 nm arranged in an array of 6256 electrodes. Due to its medical relevance influenza virus as well as anti-influenza antibodies were chosen as a model organism. Common methods to bring antibodies or proteins to biosensor surfaces are complex and time-consuming. In the present work, it was demonstrated that by applying AC electric fields influenza viruses and antibodies can be immobilized onto the nanoelectrodes within seconds without any prior chemical modification of neither the surface nor the immobilized biological object. The distribution of these immobilized objects is not uniform over the entire array, it exhibits a decreasing gradient from the outer row to the inner ones. Different causes for this gradient have been discussed, such as the vortex-shaped fluid motion above the nanoelectrodes generated by, among others, electrothermal fluid flow. It was demonstrated that parts of the accumulated material are permanently immobilized to the electrodes. This is a unique characteristic of the presented system since in the literature the AC electrokinetic immobilization is almost entirely presented as a method just for temporary immobilization. The spatial distribution of the immobilized viral material or the anti-influenza antibodies at the electrodes was observed by either the combination of fluorescence microscopy and deconvolution or by super-resolution microscopy (STED). On-chip immunoassays were performed to examine the suitability of the functionalized electrodes as a potential affinity-based biosensor. Two approaches were pursued: A) the influenza virus as the bio-receptor or B) the influenza virus as the analyte. Different sources of error were eliminated by ELISA and passivation experiments. Hence, the activity of the immobilized object was inspected by incubation with the analyte. This resulted in the successful detection of anti-influenza antibodies by the immobilized viral material. On the other hand, a detection of influenza virus particles by the immobilized anti-influenza antibodies was not possible. The latter might be due to lost activity or wrong orientation of the antibodies. Thus, further examinations on the activity of by AC electric fields immobilized antibodies should follow. When combined with microfluidics and an electrical read-out system, the functionalized chips possess the potential to serve as a rapid, portable, and cost-effective point-of-care (POC) device. This device can be utilized as a basis for diverse applications in diagnosing and treating influenza, as well as various other pathogens.
Late-type stars are by far the most frequent stars in the universe and of fundamental interest to various fields of astronomy – most notably to Galactic archaeology and exoplanet research. However, such stars barely change during their main sequence lifetime; their temperature, luminosity, or chemical composition evolve only very slowly over the course of billions of years. As such, it is difficult to obtain the age of such a star, especially when it is isolated and no other indications (like cluster association) can be used. Gyrochronology offers a way to overcome this problem.
Stars, just like all other objects in the universe, rotate and the rate at which stars rotate impacts many aspects of their appearance and evolution. Gyrochronology leverages the observed rotation rate of a late-type main sequence star and its systematic evolution to estimate their ages. Unlike the above-mentioned parameters, the rotation rate of a main sequence star changes drastically throughout its main sequence lifetime; stars spin down. The youngest stars rotate every few hours, whereas much older stars rotate only about once a month, or – in the case of some late M-stars – once in a hundred days. Given that this spindown is systematic (with an additional mass dependence), it gave rise to the idea of using the observed rotation rate of a star (and its mass or a suitable proxy thereof) to estimate a star’s age. This has been explored widely in young stellar open clusters but remains essentially unconstrained for stars older than the sun, and K and M stars older than 1 Gyr.
This thesis focuses on the continued exploration of the spindown behavior to assess, whether gyrochronology remains applicable for stars of old ages, whether it is universal for late-type main sequence stars (including field stars), and to provide calibration mileposts for spindown models. To accomplish this, I have analyzed data from Kepler space telescope for the open clusters Ruprecht 147 (2.7 Gyr old) and M 67 (4 Gyr). Time series photometry data (light curves)
were obtained for both clusters during Kepler’s K2 mission. However, due to technical limitations and telescope malfunctions, extracting usable data from the K2 mission to identify (especially long) rotation periods requires extensive data preparation.
For Ruprecht 147, I have compiled a list of about 300 cluster members from the literature and adopted preprocessed light curves from the Kepler archive where available. They have been cleaned of the gravest of data artifacts but still contained systematics. After correcting them for said artifacts, I was able to identify rotation periods in 31 of them.
For M 67 more effort was taken. My work on Ruprecht 147 has shown the limitations imposed by the preselection of Kepler targets. Therefore, I adopted the time series full frame image directly and performed photometry on a much higher spatial resolution to be able to obtain data for as many stars as possible. This also means that I had to deal with the ubiquitous artifacts in Kepler data. For that, I devised a method that correlates the artificial flux variations with the ongoing drift of the telescope pointing in order to remove it. This process was a large success and I was able to create light curves whose quality match and even exceede those that were created by the Kepler mission – all while operating on higher spatial resolution and processing fainter stars. Ultimately, I was able to identify signs of periodic variability in the (created) light curves for 31 and 47 stars in Ruprecht 147 and M 67, respectively. My data connect well to bluer stars of cluster of the same age and extend for the first time to stars redder than early-K and older than 1 Gyr. The cluster data show a clear flattening in the distribution of Ruprecht 147 and even a downturn for M 67, resulting in a somewhat sinusoidal shape. With that, I have shown that the systematic spindown of stars continues at least until 4 Gyr and stars continue to live on a single surface in age-rotation periods-mass space which allows gyrochronology to be used at least up to that age. However, the shape of the spindown – as exemplified by the newly discovered sinusoidal shape of the cluster sequence – deviates strongly from the expectations.
I then compiled an extensive sample of rotation data in open clusters – very much including my own work – and used the resulting cluster skeleton (with each cluster forming a rip in color-rotation period-mass space) to investigate if field stars follow the same spindown as cluster stars. For the field stars, I used wide binaries, which – with their shared origin and coevality – are in a sense the smallest possible open clusters. I devised an empirical method to evaluate the consistency between the rotation rates of the wide binary components and found that the vast majority of them are in fact consistent with what is observed in open clusters. This leads me to conclude that gyrochronology – calibrated on open clusters – can be applied to determine the ages of field stars.
Ethical issues surrounding modern computing technologies play an increasingly important role in the public debate. Yet, ethics still either doesn’t appear at all or only to a very small extent in computer science degree programs. This paper provides an argument for the value of ethics beyond a pure responsibility perspective and describes the positive value of ethical debate for future computer scientists. It also provides a systematic analysis of the module handbooks of 67 German universities and shows that there is indeed a lack of ethics in computer science education. Finally, we present a principled design of a compulsory course for undergraduate students.
A degree course in IT and business administration solely for women (FIW) has been offered since 2009 at the HTW Berlin – University of Applied Sciences. This contribution discusses student motivations for enrolling in such a women only degree course and gives details of our experience over recent years. In particular, the approach to attracting new female students is described and the composition of the intake is discussed. It is shown that the women-only setting together with other factors can attract a new clientele for computer science.
Both horizontal-to-vertical (H/V) spectral ratios and the spatial autocorrelation method (SPAC) have proven to be valuable tools to gain insight into local site effects by ambient noise measurements. Here, the two methods are employed to assess the subsurface velocity structure at the Piano delle Concazze area on Mt Etna. Volcanic tremor records from an array of 26 broadband seismometers is processed and a strong variability of H/V ratios during periods of increased volcanic activity is found. From the spatial distribution of H/V peak frequencies, a geologic structure in the north-east of Piano delle Concazze is imaged which is interpreted as the Ellittico caldera rim. The method is extended to include both velocity data from the broadband stations and distributed acoustic sensing data from a co-located 1.5 km long fibre optic cable. High maximum amplitude values of the resulting ratios along the trajectory of the cable coincide with known faults. The outcome also indicates previously unmapped parts of a fault. The geologic interpretation is in good agreement with inversion results from magnetic survey data. Using the neighborhood algorithm, spatial autocorrelation curves obtained from the modified SPAC are inverted alone and jointly with the H/V peak frequencies for 1D shear wave velocity profiles. The obtained models are largely consistent with published models and were able to validate the results from the fibre optic cable.
Reactive eutectic media based on ammonium formate for the valorization of bio-sourced materials
(2023)
In the last several decades eutectic mixtures of different compositions were successfully used as solvents for vast amount of chemical processes, and only relatively recently they were discovered to be widely spread in nature. As such they are discussed as a third liquid media of the living cell, that is composed of common cell metabolites. Such media may also incorporate water as a eutectic component in order to regulate properties such as enzyme activity or viscosity. Taking inspiration form such sophisticated use of eutectic mixtures, this thesis will explore the use of reactive eutectic media (REM) for organic synthesis. Such unconventional media are characterized by the reactivity of their components, which means that mixture may assume the role of the solvent as well as the reactant itself.
The thesis focuses on novel REM based on ammonium formate and investigates their potential for the valorization of bio-sourced materials. The use of REM allows the performance of a number of solvent-free reactions, which entails the benefits of a superior atom and energy economy, higher yields and faster rates compared to reactions in solution. This is evident for the Maillard reaction between ammonium formate and various monosaccharides for the synthesis of substituted pyrazines as well as for a Leuckart type reaction between ammonium formate and levulinic acid for the synthesis of 5-methyl-2-pyrrolidone. Furthermore, reaction of ammonium formate with citric acid for the synthesis of yet undiscovered fluorophores, shows that synthesis in REM can open up unexpected reaction pathways.
Another focus of the thesis is the study of water as a third component in the REM. As a result, the concept of two different dilution regimes (tertiary REM and in REM in solvent) appears useful for understanding the influence of water. It is shown that small amounts of water can be of great benefit for the reaction, by reducing viscosity and at the same time increasing reaction yields.
REM based on ammonium formate and organic acids are employed for lignocellulosic biomass treatment. The thesis thereby introduces an alternative approach towards lignocellulosic biomass fractionation that promises a considerable process intensification by the simultaneous generation of cellulose and lignin as well as the production of value-added chemicals from REM components. The thesis investigates the generated cellulose and the pathway to nanocellulose generation and also includes the structural analysis of extracted lignin.
Finally, the thesis investigates the potential of microwave heating to run chemical reactions in REM and describes the synergy between these two approaches. Microwave heating for chemical reactions and the use of eutectic mixtures as alternative reaction media are two research fields that are often described in the scope of green chemistry. The thesis will therefore also contain a closer inspection of this terminology and its greater goal of sustainability.
The Lyman-𝛼 (Ly𝛼) line commonly assists in the detection of high-redshift galaxies, the so-called Lyman-alpha emitters (LAEs). LAEs are useful tools to study the baryonic matter distribution of the high-redshift universe. Exploring their spatial distribution not only reveals the large-scale structure of the universe at early epochs, but it also provides an insight into the early formation and evolution of the galaxies we observe today. Because dark matter halos (DMHs) serve as sites of galaxy formation, the LAE distribution also traces that of the underlying dark matter. However, the details of this relation and their co-evolution over time remain unclear. Moreover, theoretical studies predict that the spatial distribution of LAEs also impacts their own circumgalactic medium (CGM) by influencing their extended Ly𝛼 gaseous halos (LAHs), whose origin is still under investigation. In this thesis, I make several contributions to improve the knowledge on these fields using samples of LAEs observed with the Multi Unit Spectroscopic Explorer (MUSE) at redshifts of 3 < 𝑧 < 6.