@inproceedings{SchwendnerVoellmeckeHoetal.,
  author    = {Schwendner, Sascha and V{\"o}llmecke, Lars and Ho, Ai Phien and Fischer, Jens and Seim, Werner},
  title     = {TESTING OF CONNECTIONS TAKEN FROM OLD NAILED ROOF TRUSSES},
  doi       = {10.25643/bauhaus-universitaet.6362},
  pages     = {8},
  abstract  = {Experimental testing of nailed connections taken from old roof trusses is presented in this paper. To enable the further use and preservation of nailed roof trusses, it is important to understand how the nail corrosion and aging processes of steel and wood affect the load-bearing capacity and deformation behaviour of such structures. The hypothesis was investigated whether corroded nails allow an increase in load-bearing capacity. Several old and new joints were tested in a first test series, and the results were very promising regarding the initial assumption. However, more tests must be carried out to verify the results.},
  subject      = {Holzbau},
  language  = {en}
}
@inproceedings{VoellmeckeSchwendnerHoetal.,
  author    = {V{\"o}llmecke, Lars and Schwendner, Sascha and Ho, Ai Phien and Fischer, Jens and Seim, Werner},
  title     = {Assessment of nailed connections in existing structures},
  doi       = {10.25643/bauhaus-universitaet.6361},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20230609-63615},
  pages     = {7},
  abstract  = {This paper presents the development of an assessment scheme for a visual qualitative evaluation of nailed connections in existing structures, such as board trusses. In terms of further use and preservation, a quick visual inspection will help to evaluate the quality of a structure regarding its load-bearing capacity and deformation behaviour. Tests of old and new nailed joints in combination with a rating scheme point out the correlation between the load-bearing capacity and condition of a joint. Old joints of comparatively good condition tend to exhibit better results than those of poor condition. Moreover, aged joints are generally more load-bearing than newly assembled ones.},
  subject      = {Holzbau},
  language  = {en}
}
@inproceedings{BaronMandavereCheruiyot,
  author    = {Baron, Nicole and Mandavere, Melody and Cheruiyot, Roselyne},
  title     = {SE/ NPO Ecosystems and urban Governance in Johannesburg},
  series = {ISTR, Fifteenth International Conference, Montreal, Canada},
  booktitle = {ISTR, Fifteenth International Conference, Montreal, Canada},
  doi       = {10.25643/bauhaus-universitaet.6364},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20230517-63643},
  pages     = {47},
  abstract  = {This paper presents initial findings from the empirical analysis of community based social enterprise (SE) and non-profit organisation (NPO) ecosystems in Johannesburg. SEs and NPOs are widely recognised as contributors to the resilience of marginalised urban communities. However, the connection between these organisations , urban governance, and community resilience has not yet been sufficiently understood , particularly in African urban contexts. The 'Resilient Urban Communities' project focuses on Johannesburg as a case study to shed light on this under-researched topic. The key to exploring it is understanding SEs and NPOs as providers of public services, job creators, and promoters of good governance, all of which contribute to community resilience. Using this premise as a starting point, this paper investigates ecosystem conditions with a particular focus on state-civil society partnerships. Empirical data was generated through semi-struc-tured interviews and analysed with a grounded theory approach. Preliminary results of this ongoing research reveal that urban geography is a relevant ecosystem factor for SEs and NPOs from marginalised communities. We also suggest that co-production could be an opportunity for growth within the investigated state-civil society partnership.},
  subject      = {S{\"u}dafrika},
  language  = {en}
}
@inproceedings{Dokhanchi,
  author    = {Dokhanchi, Najmeh Sadat},
  title     = {Acoustic travel time tomography: Applicability of an array of directional sound sources},
  editor    = {Arnold, J{\"o}rg},
  doi       = {10.25643/bauhaus-universitaet.4658},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220622-46589},
  abstract  = {The technique of Acoustic travel-time TOMography (ATOM) allows for measuring the distribution of air temperatures throughout the entire room based on the determined sound-travel-times of early reflections, currently up to second order reflections. The number of detected early reflections in the room impulse response (RIR) which stands for the desired sound paths inside the room, has a significant impact on the resolution of reconstructed temperatures. This study investigates the possibility of utilizing an array of directional sound sources for ATOM measurements instead of a single omnidirectional loudspeaker used in the previous studies [1-3]. The developed measurement setup consists of two directional sound sources placed near the edge of the floor in the climate chamber of the Bauhaus-University Weimar and one omnidirectional receiver at center of the room near the ceiling. In order to compensate for the reduced number of sound paths when using directional sound sources, it is proposed to take high-energy early reflections up to third order into account. For this purpose, the simulated travel times up to third-order image sources were implemented in the image source model (ISM) algorithm, by which these early reflections can be detected effectively for air temperature reconstructions. To minimize the uncertainties of travel-times estimation due to the positioning of the sound transducers inside the room, measurements were conducted to determine the exact emitting point of the utilized sound source i.e. its acoustic center (AC). For these measurements, three types of excitation signals (MLS, linear and logarithmic chirp signals) with various frequency ranges were used considering that the acoustic center of a sound source is a frequency dependent parameter [4]. Furthermore, measurements were conducted to determine an optimum excitation signal based on the given condition of the ATOM measurement set-up which defines an optimum method for the RIR estimation correspondingly. Finally, the uncertainty of the measuring system utilizing an array of directional sound sources was analyzed.},
  subject      = {Bauphysik},
  language  = {en}
}
@inproceedings{KieselEngelsVoelker,
  author    = {Kiesel, Gerd and Engels, Merit and V{\"o}lker, Conrad},
  title     = {Energetische Transformation im l{\"a}ndlichen Raum - Aufbau eines prozessorientierten Entwicklungs- und Moderationsmodells},
  series = {Schriftenreihe des Fachgebiets Bauphysik/Energetische Geb{\"a}udeoptimierung},
  booktitle = {Schriftenreihe des Fachgebiets Bauphysik/Energetische Geb{\"a}udeoptimierung},
  editor    = {Kornadt, Oliver and Carrigan, Svenja and Hofmann, Markus and V{\"o}lker, Conrad},
  publisher = {Eigenverlag Technische Universit{\"a}t Kaiserslautern},
  address   = {Kaiserslautern},
  isbn      = {978-3-95974-176-7},
  issn      = {2363-8206},
  doi       = {10.25643/bauhaus-universitaet.4656},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220617-46566},
  pages     = {3},
  abstract  = {Kleine Kommunen im l{\"a}ndlichen Raum sind aufgrund ihrer oft eingeschr{\"a}nkten personellen und finanziellen Kapazit{\"a}ten bisher eher sporadisch in den Themenfeldern Energieeffizienz und Erneuerbare Energien aktiv. Immer wieder stellt sich daher Frage, wie die Klimaschutzstrategien des Bundes und der L{\"a}nder dort mit dem verf{\"u}gbaren Personal kosteng{\"u}nstig realisierbar sind. Vor diesem Hintergrund wird ein Werkzeug entwickelt, mit dessen Hilfe der aktive Einstieg in diese Thematik mit geringen Aufwand und {\"u}berwiegend barrierefrei m{\"o}glich ist. Der Aufbau eines prozessorientierten Entwicklungs- und Moderationsmodells zur Erprobung und Umsetzung bezahlbarer Handlungsoptionen f{\"u}r Energieeinsparungen und effizienten Energieeinsatz im {\"u}berwiegend l{\"a}ndlichen gepr{\"a}gten Raum ist der Schwerpunkt der Softwarel{\"o}sung. Kommunen werden mit deren Hilfe in die Lage versetzt, in die notwendigen Prozesse der Energie- und W{\"a}rmewende einzusteigen. Dabei soll der modulare Aufbau die regul{\"a}ren Schritte notwendiger (integrierter) Planungsprozesse nicht vollst{\"a}ndig ersetzen. Vielmehr k{\"o}nnen innerhalb der Online-Anwendung - {\"u}berwiegend automatisiert - konkrete Maßnahmenvorschl{\"a}ge erstellt werden, die ein solides Fundament der k{\"u}nftigen energetischen Entwicklung der Kommunen darstellen. F{\"u}r eine gezielte Validierung der Ergebnisse und der Ableitung potentieller Maßnahmen werden f{\"u}r die Erprobung Modellkommunen in Th{\"u}ringen, Bayern und Hessen als Reallabore einbezogen. Das Tool steht bisher zun{\"a}chst nur den beteiligten Modellkommunen zur Verf{\"u}gung. Die entwickelte Softwarel{\"o}sung soll k{\"u}nftig Schritt f{\"u}r Schritt allen interessierten Kommunen mit diversen Hilfsmitteln und einer Vielzahl anderer praktischer Bestandteile zur Verf{\"u}gung gestellt werden.},
  subject      = {Modellierung},
  language  = {de}
}
@inproceedings{HartmannAlsaadVoelker,
  author    = {Hartmann, Maria and Alsaad, Hayder and V{\"o}lker, Conrad},
  title     = {Das Potential von Fassadenbegr{\"u}nungen zur Verringerung des W{\"a}rmeinseleffekts: Simulation eines Beispielquartiers},
  series = {Bauphysiktage Kaiserslautern 2022},
  booktitle = {Bauphysiktage Kaiserslautern 2022},
  address   = {Kaiserslautern},
  isbn      = {978-3-95974-176-7},
  issn      = {2363-8206},
  doi       = {10.25643/bauhaus-universitaet.4667},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220713-46676},
  pages     = {147-149},
  abstract  = {Die Auswirkungen einer Fassadenbegr{\"u}nung auf den W{\"a}rmeinseleffekt in Stuttgart wurde f{\"u}r eine Hitzeperiode numerisch simuliert und bewertet. Die Ergebnisse zeigten positive Auswirkungen innerhalb des Simulationsgebiets sowie eine geringe Fernwirkung auf benachbarte Stadtquartiere. Diese {\"A}nderungen k{\"o}nnen zur Verbesserung des thermischen Komforts im Außenraum beitragen. Eine reduzierte Temperatur der Außenoberfl{\"a}che f{\"u}hrt dar{\"u}ber hinaus auch zu einer geringeren Oberfl{\"a}chentemperatur der Wandinnenseite, welche die Innenraumtemperatur beeinflusst. Folglich kann die thermische Behaglichkeit auch im Innenraum erh{\"o}ht werden.},
  subject      = {Mikroklima},
  language  = {de}
}
@inproceedings{GeskeBenzVoelker,
  author    = {Geske, Mara and Benz, Alexander and V{\"o}lker, Conrad},
  title     = {Anwendung georeferenzierter Bilddaten bei energetischen Quartiersanalysen},
  series = {Tagungsband Bauphysiktage Kaiserslautern 2022},
  booktitle = {Tagungsband Bauphysiktage Kaiserslautern 2022},
  editor    = {Kornadt, Oliver and Carrigan, Svenja and Hofmann, Markus and V{\"o}lker, Conrad},
  publisher = {Eigenverlag der Technischen Universit{\"a}t Kaiserslautern},
  address   = {Kaiserslautern},
  isbn      = {987-3-95974-176-7},
  issn      = {2363-8206},
  doi       = {10.25643/bauhaus-universitaet.4654},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220617-46544},
  pages     = {127-129},
  abstract  = {Bei Analysen des Geb{\"a}udebestands im Quartierskontext werden zu Dokumentationszwecken viele Bilddaten erzeugt. Diese Daten sind im Nachhinein h{\"a}ufig keinen eindeutig genauen Standorten und Blickwinkeln auf das Bauwerk zuzuordnen. Insbesondere gilt dies f{\"u}r Ortsunkundige oder f{\"u}r Detailaufnahmen. Eine zus{\"a}tzliche Herausforderung stellt die Aufnahme von W{\"a}rmebr{\"u}cken- oder andersartigen Geb{\"a}udedetails durch Thermogramme dar. In der Praxis kommen hier oftmals analoge, fehleranf{\"a}llige L{\"o}sungen zum Einsatz. Durch die Nutzung von Georeferenzierung kann diese L{\"u}cke geschlossen und eine eindeutige Kommunikation und Auswertung gew{\"a}hrleistet werden. Im Gegensatz zu den {\"u}blichen Kameras sind Smartphones nach Stand der Technik ausreichend ausgestattet, um neben Daten zu Standort auch die Orientierungswinkel einer Bildaufnahme zu dokumentieren. Die georefenzierten Bilder k{\"o}nnen auf Grundlage der in den sogenannten Exif-Daten mitgeschriebenen Informationen h{\"a}ndisch in ein bestehendes Quartiersmodell integriert werden. Anhand eines universit{\"a}ren Musterquartiers wird die nutzerfreundliche Realisierung beispielhaft erprobt und auf ihre Potentiale zur Automatisierung in Python untersucht. Hierf{\"u}r wurde ein bestehendes Quartiersmodell als geometrische Grundlage genutzt und um RGB-Bilder sowie Thermogramme erweitert. Das beschriebene Vorgehen wird im Rahmen der Anwendung auf seinen m{\"o}glichen Einsatz im Rahmen einer energetischen Quartierserfassung sowie einer Bauschadensdokumentation untersucht. Mit dem vorliegenden Beitrag wird dem Nutzenden ein Werkzeug bereitgestellt, das die hochwertige Dokumentation einer Bestandserfassung, auch im Quartierskontext, erm{\"o}glicht.},
  subject      = {Quartiersanalyse},
  language  = {de}
}
@inproceedings{AlsaadVoelker,
  author    = {Alsaad, Hayder and V{\"o}lker, Conrad},
  title     = {Measuring and visualizing the flow supplied by personalized ventilation},
  series = {Proceedings Book Roomvent 2020},
  booktitle = {Proceedings Book Roomvent 2020},
  address   = {Turin, Italy},
  doi       = {10.25643/bauhaus-universitaet.4657},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220622-46573},
  abstract  = {This study investigates the flow supplied by personalized ventilation (PV) by means of anemometer measurements and schlieren visualization. The study was conducted using a thermal manikin to simulate a seated occupant facing a PV outlet. Air velocity was measured at multiple points in the flow field; the collected velocity values were used to calculate the turbulence intensity. Results indicated that PV was supplying air with low turbulence intensity that was able to penetrate the convective boundary layer of the manikin to supply clean air for inhalation. The convective boundary layer, however, obstructed the supplied flow and reduced its velocity by a total of 0.26 m/s. The PV flow preserved its value until about 10 cm from the face where velocity started to drop. Further investigations were conducted to test a PV diffuser with a relatively large outlet diameter (18 cm). This diffuser was developed using 3d-modelling and 3d-printing. The diffuser successfully distributed the flow over the larger outlet area. However, the supplied velocity and turbulence fields were not uniform across the section.},
  subject      = {Bel{\"u}ftung},
  language  = {en}
}
@inproceedings{Dokhanchi,
  author    = {Dokhanchi, Najmeh Sadat},
  title     = {Reconstruction of the indoor air temperature distribution using acoustic travel-time tomography},
  editor    = {Arnold, J{\"o}rg},
  doi       = {10.25643/bauhaus-universitaet.4659},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20220622-46593},
  abstract  = {Acoustic travel-time tomography (ATOM) is being increasingly considered recently as a remote sensing methodology to determine the indoor air temperatures distribution. It employs the relationship between the sound velocities along sound-paths and their related travel-times through measured room-impulse-response (RIR). Thus, the precise travel-time estimation is of critical importance which can be performed by applying an analysis time-window method. In this study, multiple analysis time-windows with different lengths are proposed to overcome the challenge of accurate detection of the travel-times at RIR. Hence, the ATOM-temperatures distribution has been measured at the climate chamber lab of the Bauhaus-University Weimar. As a benchmark, the temperatures of NTC thermistors are compared to the reconstructed temperatures derived from the ATOM technique illustrating this technique can be a reliable substitute for traditional thermal sensors. The numerical results indicate that the selection of an appropriate analysis time-window significantly enhances the accuracy of the reconstructed temperatures distribution.},
  subject      = {Bauphysik},
  language  = {en}
}
@inproceedings{KleinerRoessler,
  author    = {Kleiner, Florian and R{\"o}ßler, Christiane},
  title     = {Utilizing Modern FIB/SEM Technology and EDS for 3D Imaging of Hydrated Alite and its Pore Space},
  series = {ERICA-CASH II Final Converence},
  booktitle = {ERICA-CASH II Final Converence},
  doi       = {10.25643/bauhaus-universitaet.4455},
  url       = {http://nbn-resolving.de/urn:nbn:de:gbv:wim2-20210702-44555},
  pages     = {2},
  abstract  = {The exploration of cementitious materials using scanning electron microscopes (SEM) is mainly done using fractured or polished surfaces. This leads to high-resolution 2D-images that can be combined using EDX and EBSD to unveil details of the microstructure and composition of materials. Nevertheless, this does not provide a quantitative insight into the three-dimensional fine structure of for example C-S-H phases. The focused ion beam (FIB) technology can cut a block of material in thin layers of less than 10 nm. This gives us a volume of 1000 μm³ with a voxel resolution of down to 4 x 4 x 10 nm³. The results can be combined with simultaneously acquired EDX data to improve image segmentation. Results of the investigation demonstrate that it is possible to obtain close-to-native 3D-visualisation of the spatial distribution of unreacted C3S, C-S-H and CH. Additionally, an optimized preparation method allows us to quantify the fine structure of C-S-H phases (length, aspect ratio, …) and the pore space.},
  subject      = {Rasterelektronenmikroskop},
  language  = {en}
}