@article{52097,
  author       = {{Hami Dindar, Iman and Mirzaei, Mona and Baumhögger, Elmar and Lutters, Nicole and Kenig, Eugeny Y.}},
  issn         = {{0021-9568}},
  journal      = {{Journal of Chemical & Engineering Data}},
  keywords     = {{General Chemical Engineering, General Chemistry}},
  publisher    = {{American Chemical Society (ACS)}},
  title        = {{{Experimental and Theoretical Investigation of CO2 Absorption in Aqueous Solution of Glucosamine: Material Property and Equilibrium Data}}},
  doi          = {{10.1021/acs.jced.3c00554}},
  year         = {{2024}},
}

@inproceedings{53822,
  abstract     = {{Piezoelektrische Keramiken finden sowohl in Sensoren als auch in Aktoren Anwendung. Bei Hochleistungs-Ultraschallanwendungen sind diese Komponenten erheblichen elektrischen und mechanischen Belastungen ausgesetzt, was zum Auftreten nichtlinearer Effekte führt. Um das nichtlineare Materialverhalten piezoelektrischer Keramiken zu charakterisieren, kann eine statische mechanische Last aufgebracht werden, die den mechanischen Arbeitspunkt verschiebt. Durch Variation dieser statischen mechanischen Belastung kann das lineare Verhalten in jedem Betriebspunkt charakterisiert werden, woraufhin die nichtlinearen Eigenschaften des Materials angenähert werden können. Allerdings ist die Sicherstellung einer homogenen mechanischen Last anspruchsvoll. Alternativ kann eine hydrostatische Belastung realisiert werden, indem die Probe in einen Behälter gegeben wird, der mit unter Druck stehendem Fluid gefüllt ist. Dadurch wird eine gleichmäßige Lastverteilung über die Oberfläche der Probe erreicht.

In diesem Beitrag wird ein Versuchsaufbau zur Durchführung elektrischer Impedanzmessungen an piezoelektrischen Keramiken in einem Druckbehälter vorgestellt. Die Probe wird im Inneren des Druckbehälters elektrisch kontaktiert. Unter Verwendung von unter Druck stehendem Argon wird auf diese Weise die Messung der elektrischen Impedanz unter hydrostatischer Last von bis zu 200 bar ermöglicht. Anschließend wird ein inverses Verfahren angewendet, um die Materialparameter in Abhängigkeit von der aufgebrachten Last zu ermitteln.}},
  author       = {{Friesen, Olga and Pasha, Muhammad Ahsan and Schwengelbeck, Max and Claes, Leander and Baumhögger, Elmar and Henning, Bernd}},
  booktitle    = {{Fortschritte der Akustik - DAGA 2024}},
  location     = {{Hannover}},
  pages        = {{1117–1120}},
  title        = {{{Untersuchung piezoelektrischer Materialeigenschaften unter hydrostatischer Last}}},
  year         = {{2024}},
}

@article{43391,
  abstract     = {{The technical importance of paraffins as phase change materials (PCM) in heat storage systems increases. Knowledge on the thermal conductivity of paraffins is necessary for the design and optimization of heat storage systems. However, for most paraffins solely the thermal conductivity of the liquid state has been sufficiently investigated. For the solid state, precise thermal conductivity data are only known for a few paraffins, while only generalized values are available for the remainder, some of which contradict each other. In this study, a measurement setup based on the modified guarded hot plate method is developed. It is used to investigate the thermal conductivity of several paraffines in the solid state, including pure n-docosane and its compounds with different types and concentrations of graphite. For n-docosane in the solid state, the thermal conductivity is determined to be 0.49 W/(m K). A particle size of 200 μm with a spherical shape turns out to be optimal to increase the thermal conductivity. This allows the thermal conductivity of a compound with 10% graphite to increase by a factor of three compared to the pure paraffin. Furthermore, significant differences to thermal conductivity data from the literature are found.}},
  author       = {{Paul, Andreas and Baumhögger, Elmar and Dewerth, Mats-Ole and Hami Dindar, Iman and Sonnenrein, Gerrit and Vrabec, Jadran}},
  issn         = {{1388-6150}},
  journal      = {{Journal of Thermal Analysis and Calorimetry}},
  keywords     = {{Physical and Theoretical Chemistry, Condensed Matter Physics}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{Thermal conductivity of solid paraffins and several n-docosane compounds with graphite}}},
  doi          = {{10.1007/s10973-023-12107-2}},
  year         = {{2023}},
}

@inproceedings{43394,
  abstract     = {{Die für die Berechnung des Energieeffizienzindex von Haushaltskältegeräten benötigten Parameter werden durch Norm-Messungen im Neuzustand der Geräte bestimmt. Aus früheren Untersuchungen ist bekannt, dass durch verschiedene technische Alterungsmechanismen der Energieverbrauch über eine Produktlebensdauer von 18 Jahren um bis zu 33 % zunehmen kann. Ziel des vom BMWi geförderten Projekts ALGE war es, die verschie-denen Ursachen und Einflussgrößen für die Alterung von Haushaltskältegeräten zu ermitteln und eine Alterungs-funktion zu bestimmen, die den zeitlichen Verlauf des zunehmenden Energieverbrauchs beschreibt.
In diesem Projekt wurde das Alterungsverhalten von Haushaltskältegeräten durch 100 Normenergieverbrauchs-messungen an 32 real gealterten Geräten untersucht. Aus den gewonnenen Ergebnissen konnte eine Alterungs-funktion bestimmt werden, die den Anstieg des Energieverbrauchs beschreibt. Alle untersuchten Geräte wurden an der Universität Paderborn im Neuzustand vermessen und nach einer Laufzeit von bis zu 21 Jahren erneut geprüft. Bereits nach einem zweijährigen Betrieb konnte ein Mehrverbrauch von bis zu 11 % festgestellt werden. Über die durchschnittliche Produktlebensdauer von Haushaltskältegeräten von ca. 16 Jahren steigert sich der Energieverbrauch um durchschnittlich 27 %.
Im Rahmen des Projekts wurden verschiedene Systemkomponenten, wie Isolierung und Verdichter, hinsichtlich ihres Alterungsverhaltens untersucht. Bei dem im Gehäuse als Isolierung verwendeten PUR-Schaum konnte über einen Zeitraum von 31 Monaten ein Anstieg der Wärmeleitfähigkeit von 19,5 W/(m⋅K) auf 24,5 W/(m⋅K) festge-stellt werden. Zur Untersuchung der Alterung der Verdichter wurden zuvor auf einem Kalorimeterteststand ver-messene Verdichter in Geräte eingebaut. Nach einem zweijährigen Betrieb wurden diese Verdichter wieder aus-gebaut und erneut vermessen. Hierbei konnte keine Änderung des COP festgestellt werden. Zusätzlich zu den technischen Parametern wurde der Einfluss des Verbraucherverhaltens analysiert. Hier zeigte sich, dass bis zu 33 % des Gesamtenergieverbrauchs nach einer mehrjährigen Nutzungsdauer verbraucherinduziert sein können.}},
  author       = {{Paul, Andreas and Baumhögger, Elmar and Elsner, Andreas and Reineke, Michael and Kasper, Tina and Schumacher, Daniel and Vrabec, Jadran and  Hüppe, Christian and  Stamminger, Rainer and Hölscher, Heike and Stoll, Ragnar and Wagner, Hendrik and  Gries, Ulrich and Becker, Wolfgang}},
  isbn         = {{978-3-932715-55-6}},
  keywords     = {{Haushaltskältegeräte, Energieverbrauch, Alterung, Verdichter, PUR-Schaum}},
  location     = {{Magdeburg}},
  publisher    = {{Deutscher Kälte‐ und Klimatechnischer Verein e.V.}},
  title        = {{{Alterungsmechanismen von Haushaltskältegeräten}}},
  year         = {{2023}},
}

@article{29208,
  abstract     = {{The parameters required to calculate the energy efficiency of household refrigerating appliances (i.e. refrigerators, freezers and their combinations) are determined by standard measurements. According to regulations, these measurements are carried out when the appliances are new. It is known from previous studies that various technical aging mechanisms can increase electrical energy consumption by up to 36 % over a product lifespan of 18 years. In order to determine the time dependence of the energy consumption of household refrigerating appliances, repeated measurements are carried out in this work. Eleven new appliances are examined under standard measurement conditions. After just two years of operation, an additional energy consumption of up to 11 % is determined. Furthermore, 21 older appliances that had previously been measured in new condition are tested again after up to 21 years of operation. For these older appliances, an average increase of energy consumption of 28 % is found. For individual appliances, the maximum increase is 36 %. An aging model is developed on the basis of these measurement results, which may help to predict the aging-related increase of energy consumption of household refrigerating appliances. This model shows an average increase in energy consumption of 27 % for an appliance age of 16 years. Supplemental performance tests of eight compressors do not show any significant aging effects related to these devices after two years of operation. Furthermore, measurements of the thermal conductivity of aged polyurethane foam test samples are carried out and an increase of its thermal conductivity of 26 % over a period of about three years is determined.}},
  author       = {{Paul, Andreas and Baumhögger, Elmar and Elsner, Andreas and Reineke, Michael and Hueppe, Christian and Stamminger, Rainer and Hoelscher, Heike and Wagner, Hendrik and Gries, Ulrich and Becker, Wolfgang and Vrabec, Jadran}},
  issn         = {{1359-4311}},
  journal      = {{Applied Thermal Engineering}},
  keywords     = {{Industrial and Manufacturing Engineering, Energy Engineering and Power Technology}},
  publisher    = {{Elsevier BV}},
  title        = {{{Impact of aging on the energy efficiency of household refrigerating appliances}}},
  doi          = {{10.1016/j.applthermaleng.2021.117992}},
  volume       = {{205}},
  year         = {{2022}},
}

@article{30678,
  author       = {{Javed, Muhammad Ali and Vater, Sebastian and Baumhögger, Elmar and Windmann, Thorsten and Vrabec, Jadran}},
  issn         = {{0021-9614}},
  journal      = {{The Journal of Chemical Thermodynamics}},
  keywords     = {{Physical and Theoretical Chemistry, General Materials Science, Atomic and Molecular Physics, and Optics}},
  publisher    = {{Elsevier BV}},
  title        = {{{Apparatus for the measurement of the thermodynamic speed of sound of diethylene glycol and triethylene glycol}}},
  doi          = {{10.1016/j.jct.2022.106766}},
  year         = {{2022}},
}

@article{31808,
  author       = {{Khider Abbas Abbas, Wameedh and Baumhögger, Elmar and Vrabec, Jadran}},
  issn         = {{2590-1745}},
  journal      = {{Energy Conversion and Management: X}},
  keywords     = {{Energy Engineering and Power Technology, Fuel Technology, Nuclear Energy and Engineering, Renewable Energy, Sustainability and the Environment}},
  publisher    = {{Elsevier BV}},
  title        = {{{Experimental investigation of organic Rankine cycle performance using alkanes or hexamethyldisiloxane as a working fluid}}},
  doi          = {{10.1016/j.ecmx.2022.100244}},
  year         = {{2022}},
}

@article{33255,
  author       = {{Betken, Benjamin and Beckmüller, Robin and Ali Javed, Muhammad and Baumhögger, Elmar and Span, Roland and Vrabec, Jadran and Thol, Monika}},
  issn         = {{0021-9614}},
  journal      = {{The Journal of Chemical Thermodynamics}},
  keywords     = {{Physical and Theoretical Chemistry, General Materials Science, Atomic and Molecular Physics, and Optics}},
  publisher    = {{Elsevier BV}},
  title        = {{{Thermodynamic Properties for 1-Hexene – Measurements and Modeling}}},
  doi          = {{10.1016/j.jct.2022.106881}},
  year         = {{2022}},
}

@inproceedings{31243,
  author       = {{Hami Dindar, Iman and Baumhögger, Elmar and Lutters, Nicole and Kenig, Eugeny}},
  booktitle    = {{Jahrestreffen der ProcessNet Fachgruppen Fluidverfahrenstechnik und Hochdruckverfahrenstechnik}},
  location     = {{Frankfurt am Main}},
  title        = {{{Wässrige Aminozuckerlösungen als neue Lösungsmittel zur CO2-Abscheidung}}},
  year         = {{2022}},
}

@article{20925,
  author       = {{Abbas, Wameedh Khider Abbas and Linnemann, Matthias and Baumhögger, Elmar and Vrabec, Jadran}},
  issn         = {{0196-8904}},
  journal      = {{Energy Conversion and Management}},
  title        = {{{Experimental study of two cascaded organic Rankine cycles with varying working fluids}}},
  doi          = {{10.1016/j.enconman.2020.113818}},
  year         = {{2021}},
}

@article{29168,
  abstract     = {{<jats:title>Abstract</jats:title><jats:p>The homogeneous density of the liquid phase is experimentally investigated for methyl diethanolamine. Data are obtained along five isotherms in a temperature range between 300 K and 360 K for pressures up to 95 MPa. Two different apparatuses are used to measure the speed of sound for the temperatures between 322 K and 450 K with a maximum pressure of 95 MPa. These measurements and literature data are used to develop a fundamental equation of state for methyl diethanolamine. The model is formulated in terms of the Helmholtz energy and allows for the calculation of all thermodynamic properties in gaseous, liquid, supercritical, and saturation states. The experimental data are represented within their uncertainties. The physical and extrapolation behavior is validated qualitatively to ensure reasonable calculations outside of the range of validity. Based on the experimental datasets, the equation of state is valid for temperatures from 250 K to 750 K and pressures up to 100 MPa.</jats:p>}},
  author       = {{Neumann, Tobias and Baumhögger, Elmar and Span, Roland and Vrabec, Jadran and Thol, Monika}},
  issn         = {{0195-928X}},
  journal      = {{International Journal of Thermophysics}},
  keywords     = {{Condensed Matter Physics}},
  number       = {{1}},
  publisher    = {{Springer Science and Business Media LLC}},
  title        = {{{Thermodynamic Properties of Methyl Diethanolamine}}},
  doi          = {{10.1007/s10765-021-02933-7}},
  volume       = {{43}},
  year         = {{2021}},
}

@article{22925,
  author       = {{Claes, Leander and Chatwell, René Spencer and Baumhögger, Elmar and Hetkämper, Tim and Zeipert, Henning and Vrabec, Jadran and Henning, Bernd}},
  issn         = {{0263-2241}},
  journal      = {{Measurement}},
  title        = {{{Measurement procedure for acoustic absorption and bulk viscosity of liquids}}},
  doi          = {{10.1016/j.measurement.2021.109919}},
  year         = {{2021}},
}

@article{20921,
  abstract     = {{The increase of the thermal conductivity of PUR foam in the insulation of the cabinet is an important cause for aging processes of household refrigerating appliances. To determine the influence of the PUR foam aging on energy consumption, the development of a new measurement method is necessary be- cause current methods influence the aging behavior of household refrigerators and are therefore not applicable in general. Based on a latent heat sink, constructed as an ice water bucket, a new measure- ment method is developed to determine the k ·A value over time. With this method, the k ·A value of four household refrigerating appliances was determined over an interval of 14 months. The k ·A value increased between 3.6% and 11.5% during this period.}},
  author       = {{Paul, Andreas and Baumhögger, Elmar and Elsner, Andreas and Moczarski, Lukas and Reineke, Michael and Sonnenrein, Gerrit and Hueppe, Christian and Stamminger, Rainer and Hoelscher, Heike and Wagner, Hendrik and Gries, Ulrich and Freiberger, Alfred and Becker, Wolfgang and Vrabec, Jadran}},
  issn         = {{0140-7007}},
  journal      = {{International Journal of Refrigeration}},
  pages        = {{235--242}},
  title        = {{{Determining the heat flow through the cabinet walls of household refrigerating appliances}}},
  doi          = {{10.1016/j.ijrefrig.2020.10.007}},
  year         = {{2021}},
}

@article{17589,
  author       = {{Sonnenrein, G. and Baumhögger, Elmar and Elsner, A. and Morbach, A. and Neukötter, M. and Paul, A. and Vrabec, J.}},
  issn         = {{0140-7007}},
  journal      = {{International Journal of Refrigeration}},
  title        = {{{Improving the performance of household refrigerating appliances through the integration of phase change materials in the context of the new global refrigerator standard IEC 62552:2015}}},
  doi          = {{10.1016/j.ijrefrig.2020.07.025}},
  year         = {{2020}},
}

@article{16848,
  author       = {{Javed, Muhammad Ali and Rüther, Moritz and Baumhögger, Elmar and Vrabec, Jadran}},
  issn         = {{0021-9568}},
  journal      = {{Journal of Chemical & Engineering Data}},
  title        = {{{Density and Thermodynamic Speed of Sound of Liquid Vinyl Chloride}}},
  doi          = {{10.1021/acs.jced.9b01133}},
  year         = {{2020}},
}

@inproceedings{15490,
  author       = {{Claes, Leander and Baumhögger, Elmar and Rüther, Torben and Gierse, Jan and Tröster, Thomas and Henning, Bernd}},
  booktitle    = {{Fortschritte der Akustik - DAGA 2020}},
  pages        = {{1077--1080}},
  title        = {{{Reduction of systematic measurement deviation in acoustic absorption measurement systems}}},
  year         = {{2020}},
}

@article{21514,
  abstract     = {{The influence of latent heat storage elements on the cooling performance and the temperature rise time of household refrigerating appliances is studied experimentally in the context of the “new global refriger- ator standard”IEC 62552:2015. In addition to the daily energy consumption, this international standard- ization introduced performance tests for cooling capacity and temperature rise time. While the cooling capacity has long been anchored in various test procedures of consumer organizations, the temperature rise time, which has only been tested on freezers so far, will be a decisive factor in the future. Moreover, the need for so-called "smart appliances" that may balance power consumption is increasing since such devices may compensate the volatility of renewable energies and thus stabilize the power grid. Against this background, eight commercial household refrigerators and refrigerator-freezers are equipped with polymer-bound phase change materials (PCM) and their performance is determined under the new stan- dard test conditions. The results show that the introduction of PCM increases the cooling capacity by up to 33 % and also increases the temperature rise time by up to 145 %, without affecting power consump- tion, as compared to the unmodified refrigeration appliances.}},
  author       = {{Sonnenrein, Gerrit and Baumhögger, Elmar and Elsner, Andreas and Morbach, A. and Neukötter, Moritz and Paul, Andreas and Vrabec, J.}},
  issn         = {{0140-7007}},
  journal      = {{International Journal of Refrigeration}},
  pages        = {{448--456}},
  publisher    = {{Elsevier}},
  title        = {{{Improving the performance of household refrigerating appliances through the integration of phase change materials in the context of the new global refrigerator standard IEC 62552:2015}}},
  doi          = {{10.1016/j.ijrefrig.2020.07.025}},
  volume       = {{119}},
  year         = {{2020}},
}

@article{16305,
  author       = {{Linnemann, Matthias and Nikolaychuk, Pavel Anatolyevich and Muñoz-Muñoz, Y. Mauricio and Baumhögger, Elmar and Vrabec, Jadran}},
  issn         = {{0021-9568}},
  journal      = {{Journal of Chemical & Engineering Data}},
  pages        = {{1180--1188}},
  title        = {{{Henry’s Law Constant of Noble Gases in Water, Methanol, Ethanol, and Isopropanol by Experiment and Molecular Simulation}}},
  doi          = {{10.1021/acs.jced.9b00565}},
  year         = {{2019}},
}

@article{13143,
  author       = {{Claes, Leander and Hülskämper, Lars Moritz and Baumhögger, Elmar and Feldmann, Nadine and Chatwell, René Spencer and Vrabec, Jadran and Henning, Bernd}},
  issn         = {{2196-7113}},
  journal      = {{tm - Technisches Messen}},
  pages        = {{2--6}},
  title        = {{{Acoustic absorption measurement for the determination of the volume viscosity of pure fluids / Messverfahren für die akustischen Absorption zur Bestimmung der Volumenviskosität reiner Fluide}}},
  doi          = {{10.1515/teme-2019-0038}},
  year         = {{2019}},
}

@article{13158,
  author       = {{Thol, Monika and Javed, Muhammad Ali and Baumhögger, Elmar and Span, Roland and Vrabec, Jadran}},
  issn         = {{0888-5885}},
  journal      = {{Industrial & Engineering Chemistry Research}},
  pages        = {{9617--9635}},
  title        = {{{Thermodynamic Properties of Dodecamethylpentasiloxane, Tetradecamethylhexasiloxane, and Decamethylcyclopentasiloxane}}},
  doi          = {{10.1021/acs.iecr.9b00608}},
  year         = {{2019}},
}