Pseudo-document simulation for comparing LDA, GSDMM and GPM topic models on short and sparse text using Twitter data.

Topic models are a useful and popular method to find latent topics of documents. However, the short and sparse texts in social media micro-blogs such as Twitter are challenging for the most commonly used Latent Dirichlet Allocation (LDA) topic model. We compare the performance of the standard LDA topic model with the Gibbs Sampler Dirichlet Multinomial Model (GSDMM) and the Gamma Poisson Mixture Model (GPM), which are specifically designed for sparse data.

Interaction of Cyanoacrylate with Metal Oxide Surfaces (Cu, Al).

The front cover artwork is provided by Prof. Maus-Friedrichs' group at the Clausthal University of Technology. The image shows the molecular interaction formed at the interface between the adhesive cyanoacrylate and a natively oxidized copper or aluminium surface.

Coupled model for microbial growth and phase mass transfer in pressurized batch reactors in the context of underground hydrogen storage.

A rising interest in a strong hydrogen economy as a part of the future net-zero economy results in an increasing necessity to store hydrogen as a raw material or an energy carrier. Experience and studies show that storing hydrogen in deep underground sites could enable microbial conversion of hydrogen. To predict and examine the loss of hydrogen, laboratory studies, and analysis are essential.

Real-Time Liquid Rate and Water Cut Prediction From the Electrical Submersible Pump Sensors Data Using Machine-Learning Algorithms.

This study presents a novel data-driven approach for calculating multiphase flow rates in electrical submersible pumped wells. Traditional methods for estimating flow rates at test separators fail to identify production trends and require additional costs for maintenance. In response, virtual flow metering (VFM) has emerged as an attractive research area in the oil and gas industry.

On the Advantages of Microwave Photonic Interrogation of Fiber-Based Sensors: A Noise Analysis.

Although microwave photonic approaches have been used for fiber sensing applications before, most contributions in the past dealt with evaluating the sensor signal's amplitude. Carrying this topic on, the authors previously presented a scheme for the interrogation of fiber sensors that was based on a fiber Bragg grating's phase response for the electrical signal. However, neither has the measurement setup been analyzed nor have the amplitude and phase-based approaches been compared in detail before.

Anatomic and neurochemical analysis of the palpal olfactory system in the red flour beetle , HERBST.

The paired antennal lobes were long considered the sole primary processing centers of the olfactory pathway in holometabolous insects receiving input from the olfactory sensory neurons of the antennae and mouthparts. In hemimetabolous insects, however, olfactory cues of the antennae and palps are processed separately. For the holometabolous red flour beetle , we could show that primary processing of the palpal and antennal olfactory input also occurs separately and at distinct neuronal centers.

A New Way to 2,3,4-Trisubstituted Benzo[]quinolines: Synthesis, Consecutive Reactions and Cellular Activities †.

The reaction of mercaptoacetic acid esters with pentachloro-2-nitro-1,3-butadiene provides the appropriate precursors for the synthesis of 2,3,4-trisubstituted benzo[]quinolines. These heterocycles are easily accessible via a single-step reaction with naphthalen-1-amine or anthracen-1-amine as the precursor. Due to the steric bulk and high electron density ring, the ring closure of benzo[]quinolines takes place exclusively.

Protein-protein interactions in solutions of monoclonal antibodies probed by the dependence of the high-frequency viscosity on temperature and concentration.

Using a quartz crystal microbalance with dissipation monitoring (QCM-D), the complex high-frequency viscosity, = η' - η'', of concentrated solutions of a monoclonal antibody (mAb) was studied with respect to its dependence on temperature, , and concentration, . Lysozyme and bovine serum albumin (BSA) served as reference materials. Viscoelasticity was found for the mAb solution, while the reference materials behaved like Newtonian liquids.

Social preferences in the public goods game-An Agent-Based simulation with EconSim.

Using a reinforcement-learning algorithm, we model an agent-based simulation of a public goods game with endogenous punishment institutions. We propose an outcome-based model of social preferences that determines the agent's utility, contribution, and voting behavior during the learning procedure. Comparing our simulation to experimental evidence, we find that the model can replicate human behavior and we can explain the underlying motives of this behavior.

Gas Phase Reaction of Silane with Water at Different Temperatures and Supported by Plasma.

The interaction of silane and water is discussed controversially in literature: some authors suggest monosilane and water react kinetically and sufficiently fast enough to remove water, while others state the reaction occurs only at elevated temperatures. This question is of technological interest for the removal of unavoidable water residues in Ar gases. Thermodynamic calculations show that virtually complete removal of water is expected with superstoichiometric silane addition.

Polyether-tethered imidazole-2-thiones, imidazole-2-selenones and imidazolium salts as collectors for the flotation of lithium aluminate and spodumene.

Imidazolium salts were prepared which possess 2-ethoxyethyl pivalate or 2-(2-ethoxyethoxy)ethyl pivalate groups as amphiphilic side chains with oxygen donors as well as -butyl substituents as hydrophobic groups. The N-heterocyclic carbenes of the salts, characterized by Li and C NMR spectroscopy as well as by Rh and Ir complex formation, were used as starting materials for the preparation of the corresponding imidazole-2-thiones and imidazole-2-selenones. Flotation experiments in Hallimond tubes under variation of the air flow, pH, concentration and flotation time were performed.

Interaction of Cyanoacrylate with Metal Oxide Surfaces (Cu, Al).

Cyanoacrylates are an extremely reactive class of adhesives. Despite their commercial use as instant adhesives, the adhesion mechanism, especially to technically relevant oxidized metal surfaces, has not yet been sufficiently investigated. In the present work, ultra-thin ethyl cyanoacrylate films are deposited on copper oxide and aluminum oxide by spin coating and cured there.

Effect of Noise on Determining Ultrathin-Film Parameters from QCM-D Data with the Viscoelastic Model.

Quartz crystal microbalance with dissipation monitoring (QCM-D) is a well-established technique for studying soft films. It can provide gravimetric as well as nongravimetric information about a film, such as its thickness and mechanical properties. The interpretation of sets of overtone-normalized frequency shifts, ∆/, and overtone-normalized shifts in half-bandwidth, ΔΓ/, provided by QCM-D relies on a model that, in general, contains five independent parameters that are needed to describe film thickness and frequency-dependent viscoelastic properties.

Green Manufacturing for Herbal Remedies with Advanced Pharmaceutical Technology.

Herbal remedies are in most cases still manufactured with traditional equipment installations and processes. Innovative chemical process engineering methods such as modeling and process intensification with green technology could contribute to the economic and ecologic future of those botanicals. The integration of modern unit operations such as water-based pressurized hot water extraction and inline measurement devices for process analytical technology approaches in traditional extraction processes is exemplified.

Investigation of an electrolysis system with boron-doped diamond anode and gas diffusion cathode to remove water micropollutants.

Using electrolysis systems to degrade organics in wastewater encourages this technique to remove micropollutants (MPs) in different types of water. In this work, a cell consisting of an anode as a boron-doped diamond (BDD) electrode combined with a gas diffusion (GDE) cathode without a separator showed that MPs degradation can be effectively achieved. Investigating different operating parameters, it was stated that applying a low current density (2 mA/cm) and setting the Reynolds number of the electrolyte flow through the cell at the laminar range raised the treatment time by 3-fold at the same energy demand.

A New Reactor Concept for Single-Chamber Microbial Fuel Cells and Possible Anti-Fouling Strategies for Long-Term Operation.

Microbial fuel cells are a promising technology for future wastewater treatment, as it allows cleaning and power generation simultaneously. The bottleneck of microbial fuel cells is often its cathodes because they determine the power output. Gas diffusion electrodes might overcome this bottleneck due to their low production costs and high oxygen reduction rates.

Fatigue dataset for carbon fibre-reinforced polymers under uni- and multiaxial loads with varying biaxiality and proportional stress ratios.

The experimental data in this submission is related to parts of the dissertation "Bruchkurvenmodellierung von kohlenstofffaserverstärkten Kunststoffen bei mehrachsig nichtproportionaler Ermüdungsbeanspruchung" [1] and partly to further publications on the fatigue of carbon fibre-reinforced plastic [2]. The background to the experimental investigations is the need to better understand the behavior of fiber-reinforced plastics under various multiaxial loads. For this purpose, comprehensive tests ranging from uniaxial tests on unidirectional up to multiaxial tests on multidirectional specimens are conducted.

Corrosion Resistance of 316L/CuSn10 Multi-Material Manufactured by Powder Bed Fusion.

Research and industry are calling for additively manufactured multi-materials, as these are expected to create more efficient components, but there is a lack of information on corrosion resistance, especially since there is a risk of bimetallic corrosion with two metallic components. In this study, the corrosion behaviour of a multi-material made of 316L and CuSn10 is investigated before and after a stress relief annealing using linear sweep voltammetry. For this purpose, a compromise had to be found in the heat treatment parameters in order to be able to treat both materials together.

Entering a New Dimension in Powder Processing for Advanced Ceramics Shaping.

Filigree structures can be manufactured via two-photon polymerization (2PP) operating in the regime of nonlinear light absorption. For the first time, it is possible to apply this technique to the powder processing of ceramic structures with a feature size in the range of the critical defect sizes responsible for brittle fracture and, thus, affecting fracture toughness of high-performance ceramics. In this way, tailoring of advanced properties can be achieved already in the shaping process.

Influencing the froth flotation of LiAlO and melilite solid solution with ionic liquids.

In the present work experiments for single mineral flotation against LiAlO and melilite s.s. were carried out for seven ionic liquids (ILs).

Controlled Release of Tea Tree Oil from a Chitosan Matrix Containing Gold Nanoparticles.

Chitosan is a biopolymer that, due to its versatile bioactive properties, has applications in several areas, including food, medicine and pharmaceuticals. In the field of tissue engineering, chitosan can be used, for example, as a dressing to treat wounds or dermal damage, such as burns or abrasions. This work deals with the controlled release of tea tree oil from chitosan-based polymeric films and droplets containing gold nanoparticles (AuNP).

Modeling acoustic cavitation with inhomogeneous polydisperse bubble population on a large scale.

A model for acoustic cavitation flows able to depict large geometries and time scales is proposed. It is based on the Euler-Lagrange approach incorporating a novel Helmholtz solver with a non-linear acoustic attenuation model. The method is able to depict a polydisperse bubble population, which may vary locally.

Understanding Braess' Paradox in power grids.

The ongoing energy transition requires power grid extensions to connect renewable generators to consumers and to transfer power among distant areas. The process of grid extension requires a large investment of resources and is supposed to make grid operation more robust. Yet, counter-intuitively, increasing the capacity of existing lines or adding new lines may also reduce the overall system performance and even promote blackouts due to Braess' paradox.