53 results match your criteria: "Bauhaus University Weimar[Affiliation]"

This dataset presents the indoor air temperature collections using the novel technique of Acoustic travel time TOMography (ATOM) in the ultrasonic frequency range. The presented measuring system employs early reflections as sound propagation paths in addition to the travel time of the direct path, effectively combining room acoustics with tomography techniques. The data was collected across various measurement scenarios within the climate chamber laboratory at the Building Physics Department at the Bauhaus-University Weimar.

View Article and Find Full Text PDF

The present work demonstrates the development of SiC/TiS/AlSi12Cu hybrid functionally graded composite using centrifugal casting and examines its microstructural, mechanical, and tribological properties. A gradient distribution of reinforcement particles was observed with the outer region being particle-rich. EBSD analysis confirms microstructural refinement owing to titanium's grain refining properties and the formation of θ-AlCu intermetallic phase.

View Article and Find Full Text PDF

Planning for social distancing: How the legacy of historical epidemics shaped COVID-19's spread in Madrid.

Urban Stud

July 2023

Universidad de Valladolid Escuela Tecnica Superior de Arquitectura, Spain.

This paper combines historical and contemporary sources to examine 'epidemic urban planning' from the first decades of the 20th century through to the present day. It considers how infamous early 20th-century epidemics triggered the development of several urban regulations that profoundly shaped the city's future. To reduce the risk of contagion in bourgeois space, the city began displacing and spatially segregating the urban poor, leading to deprived neighbourhoods in the city's suburbs.

View Article and Find Full Text PDF

Methodological advancements in road safety research reveal an increasing inclination toward integrating spatial approaches in hot spot identification, spatial pattern analysis, and developing spatially lagged models. Previous studies on hot spot identification and spatial pattern analysis have overlooked crash severities and the spatial autocorrelation of crashes by severity, missing valuable insights into crash patterns and underlying factors. This study investigates the spatial autocorrelation of crash severity by taking two capital cities, Addis Ababa and Berlin, as a case study and compares patterns in low and high-income countries.

View Article and Find Full Text PDF

To accurately simulate the hydration process of cementitious materials, understanding the growth rate of C-S-H layers around clinker grains is crucial. Nonetheless, the thickness of the hydrate layer shows substantial variation around individual grains, depending on their surrounding. Consequently, it is not feasible to measure hydrate layers manually in a reliable and reproducible manner.

View Article and Find Full Text PDF

Characterization of the iPhone LiDAR-Based Sensing System for Vibration Measurement and Modal Analysis.

Sensors (Basel)

September 2023

Chair of Modelling and Simulation of Structures, Bauhaus University Weimar, Marienstr. 13, 99423 Weimar, Germany.

Portable depth sensing using time-of-flight LiDAR principles is available on iPhone 13 Pro and similar Apple mobile devices. This study sought to characterize the LiDAR sensing system for measuring full-field vibrations to support modal analysis. A vibrating target was employed to identify the limits and quality of the sensor in terms of noise, frequency, and range, and the results were compared to a laser displacement transducer.

View Article and Find Full Text PDF

On the Chloride Distribution in Concrete and Mortar Samples after an RCM Test.

Materials (Basel)

April 2023

Centre for Building Materials, Department of Materials Engineering, TUM School of Engineering and Design, Technical University of Munich, Franz-Langinger-Straße 10, 81245 München, Germany.

It is of essential need to face the challenges of CO reduction in industrial cement and concrete production reliable test methods in order to evaluate the performance of concretes, especially with regard to the service life of our infrastructure. The rapid chloride migration test (RCM test) is a standard method to assess the resistance against chloride ingress of concrete. However, during our study, certain critical questions arose with regard to the chloride distribution.

View Article and Find Full Text PDF

Physical exercise demonstrates a special case of aerosol emission due to its associated elevated breathing rate. This can lead to a faster spread of airborne viruses and respiratory diseases. Therefore, this study investigates cross-infection risk during training.

View Article and Find Full Text PDF

This article describes the validation of a 3D dynamic interaction model of the train-track-bridge system on a bowstring-arch railway bridge based on experimental tests. The train, track, and bridge subsystems were modeled on the basis of large-scale and highly complex finite elements models previously calibrated on the basis of experimental modal parameters. The train-bridge dynamic interaction problem, in the vertical direction, was efficiently solved using a dedicated computational application (TBI software).

View Article and Find Full Text PDF

This dataset consists mainly of two subsets. The first subset includes measurements and simulation data conducted to validate the simulation tool ENVI-met. The measurements were conducted at the campus of the Bauhaus-University Weimar in Weimar, Germany and consisted of recording exterior air temperature, globe temperature, relative humidity, and wind velocity at 1.

View Article and Find Full Text PDF

It is widely accepted that most people spend the majority of their lives indoors. Most individuals do not realize that while indoors, roughly half of heat exchange affecting their thermal comfort is in the form of thermal infrared radiation. We show that while researchers have been aware of its thermal comfort significance over the past century, systemic error has crept into the most common evaluation techniques, preventing adequate characterization of the radiant environment.

View Article and Find Full Text PDF

The realistic prediction of material damping is crucial in the design and dynamic simulation of many components in mechanical engineering. Material damping in metals occurs mainly due to the thermoelastic effect. This paper presents a new approach for implementing thermoelastic damping into finite element simulations, which provides an alternative to computationally intensive, fully coupled thermoelastic simulations.

View Article and Find Full Text PDF

Quantification of cracks in concrete thin sections considering current methods of image analysis.

J Microsc

May 2022

F. A. Finger-Institute for Building Material Science, Bauhaus-University Weimar, Coudraystr. 11B, Weimar, Thuringia, 99423, Germany.

Image analysis is used in this work to quantify cracks in concrete thin sections via modern image processing. Thin sections were impregnated with a yellow epoxy resin, to increase the contrast between voids and other phases of the concrete. By the means of different steps of pre-processing, machine learning and python scripts, cracks can be quantified in an area of up to 40 cm .

View Article and Find Full Text PDF

This dataset presents the numerical analysis of the heat and moisture transport through a facade equipped with a living wall system designated for greywater treatment. While such greening systems provide many environmental benefits, they involve pumping large quantities of water onto the wall assembly, which can increase the risk of moisture in the wall as well as impaired energetic performance due to increased thermal conductivity with increased moisture content in the building materials. This dataset was acquired through numerical simulation using the coupling of two simulation tools, namely Envi-Met and Delphin.

View Article and Find Full Text PDF

Integration of a photobioreactor for WWT by microalgae is calculated as a future alternative for cost-efficient and environmentally-friendly nutrient removal for municipal WWTPs. High growth rates and higher biogas yields (compared to conventional sewage sludge) of algal biomass can significantly improve WWTP energy balances. This study focuses on temperate climate zones with changing seasons and discusses energy potential of microalgae-enhanced wastewater treatment for an existing WWTP (32,000 PE) in Central Germany.

View Article and Find Full Text PDF

This article explores a three-dimensional solid isogeometric analysis (3D-IGA) approach based on a nonlocal elasticity theory to investigate size effects on natural frequency and critical buckling load for multi-directional functionally graded (FG) nanoshells. The multi-directional FG material uses a power law rule with three power exponent indexes concerning three parametric coordinates. Nanoshell's geometries include the square plate, cylindrical and spherical panels with the side length considered in a nanoscale with various thickness ratios.

View Article and Find Full Text PDF

Surface chemistry of mineral phases in aqueous environments generates the electrostatic forces involved in particle-particle interactions. However, few models directly take into account the influence of surface speciation and changes in solution speciation when the diffuse layer potential profiles of approaching particles overlap and affect each other. These electrostatic interactions can be quantified, ideally, through charge regulation, considering solution and surface speciation changes upon particle approach by coupling state-of-the-art surface complexation models for the two particle surfaces with a Poisson-Boltzmann type distribution of electrostatic potential and ions in the inter-particle space.

View Article and Find Full Text PDF

Objectives: Severe acute respiratory syndrome coronavirus 2 is transmitted through aerosols and droplets. Nasal high-flow therapy could possibly increase the spreading of exhalates from patients. The aim of this study is to investigate whether nasal high-flow therapy affects the range of the expiratory plume compared with spontaneous breathing.

View Article and Find Full Text PDF

The spread of breathing air when playing wind instruments and singing was investigated and visualized using two methods: (1) schlieren imaging with a schlieren mirror and (2) background-oriented schlieren (BOS). These methods visualize airflow by visualizing density gradients in transparent media. The playing of professional woodwind and brass instrument players, as well as professional classical trained singers were investigated to estimate the spread distances of the breathing air.

View Article and Find Full Text PDF

Properties of Calcium Sulfoaluminate Cement Mortar Modified by Hydroxyethyl Methyl Celluloses with Different Degrees of Substitution.

Molecules

April 2021

Key Laboratory of Advanced Civil Engineering Materials (Tongji University), Ministry of Education, School of Materials Science and Engineering, Tongji University, Shanghai 201804, China.

This paper studies the influence of hydroxyethyl methyl cellulose (HEMC) on the properties of calcium sulfoaluminate (CSA) cement mortar. In order to explore the applicability of different HEMCs in CSA cement mortars, HEMCs with higher and lower molar substitution (MS)/degree of substitution (DS) and polyacrylamide (PAAm) modification were used. At the same time, two kinds of CSA cements with different contents of ye'elimite were selected.

View Article and Find Full Text PDF

Recent experimental advances [Liu , , 2019, , 23] propose the design of graphene nanoribbon springs (GNRSs) to substantially enhance the stretchability of pristine graphene. A GNRS is a periodic undulating graphene nanoribbon, where undulations are of sinus or half-circle or horseshoe shapes. Besides this, the GNRS geometry depends on design parameters, like the pitch's length and amplitude, thickness and joining angle.

View Article and Find Full Text PDF

The rheological properties of fresh cement paste are highly influenced by a large number of parameters, among which the most important factors are the applied shear stress, and the shear history, the age of the sample and the temperature. The effects of these parameters on the yield stress (designated as structural limit stress in this work), the viscosity and the structural recovery rate (i.e.

View Article and Find Full Text PDF

A new method for the nuclear magnetic resonance (NMR) surface relaxivity calibration in hydrated cement samples is proposed. This method relies on a combined analysis of 28-d hydrated tricalcium silicate samples by scanning electron microscopy (SEM) image analysis and H-time-domain (TD)-NMR relaxometry. Pore surface and volume data for interhydrate pores are obtained from high resolution SEM images on surfaces obtained by argon broad ion beam sectioning.

View Article and Find Full Text PDF

Background: The efficiency of the braces designed for scoliotic subjects depends on configurations and also magnitudes of the forces used to stabilize and correct scoliotic curve. However, the effects of various force configurations on the spinal curves in sagittal plane should also be considered. The aim of this study was to determine the efficiency of various force configurations on scoliotic, lordotic and kyphotic curves.

View Article and Find Full Text PDF

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

View Article and Find Full Text PDF