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UV Pre-Treatment for Polycarbonate for Bonding LSR in a Multi-Component Injection Molding Process
(2019-03-01)
In this study, the influence of UVC radiation and the influence of ozone on the surface energy of specimens made of polycarbonate were investigated. In an additional step, the peeling resistance of silicone flaps, which were overmolded, onto pre-treated PC plates of multicomponent specimens were analyzed. For this purpose, the samples were exposed to UVC radiation for different lengths of time, ranging from 5 s to 3 600 s. To further evaluate the influence of the ozone created by the UVC in the presence of oxygen, ...
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Additive manufacturing of Co-Ni-Ga high-temperature shape memory alloy - Processability 3 and phase transformation behavior
(2019)
Co-Ni-Ga high-temperature shape memory alloy is additively processed by selective laser melting for the first time. Reversiblemartensitic transformation of the as-built material is proven by differential scanning calorimetry. Microstructural analysis reveals a columnar-grained microstructure due to epitaxial solidification. Columnar-grained microstructures are characterized by a very low degree of constraints being beneficial for superior functional performance in numerous shape memory alloys. However, process-induced ...
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Investigations on Tightness of Polymer-Metal Hybrids in Environments with Thermal, Media, and Mechanical Loads
(2017-07-31)
With polymer-metal hybrids becoming more commonly used as structural components it was investigated how they perform in complex environments with combined thermal, media, and mechanical loads. Special attention was put on media tightness under said loads. This paper sums up the activities of the polymer technology research group of the University of Kassel on hybrids produced by overmolding metal inserts. Investigations concerning joint strength and influence of (cyclic) temperature loads and chemical corrosion on ...
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Mechanical Properties of Polydimethylsiloxane as a Function of the Amount and Type of Crosslinking Agent
(2017-06-13)
In this investigation, a high-consistency rubber (HCR) was mixed with five different, typically used crosslinking agents that are based on organic peroxide. Furthermore, the amount of crosslinking agent was varied in order to quantify the effect on the mechanical properties. All materials were processed in a hot pressing process, and, subsequently, post-cured. The properties were characterized by the measurement of the swelling ratio, shore A-hardness, rebound resilience and tensile test. We successfully proved that ...
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Pathways towards grain boundary engineering for improved structural performance in polycrystalline Co-Ni-Ga shape memory alloys
(2018)
Co-Ni-Ga high-temperature shape memory alloys attracted a lot of scientific attention due to their superior functional material properties in recent years. In the single crystalline state Co-Ni-Ga HT-SMAs feature a good pseudoelastic response up to 500°C. However, in the polycrystalline condition Co-Ni-Ga suffers significant grain constraints and premature fracture at grain boundaries. In this regard, crystallographic orientation of the grain being involved as well as morphology and geometrical orientation of the ...
Aufsatz
Grounding IPBES experts’ views on the multiple values of nature in epistemology, knowledge and collaborative science
(2019-12-18)
This study identifies and analyses the underlying assumptions of experts involved in the first author meeting (FAM) of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES)’s Values Assessment, and how they shape understandings of the multiple values of nature. We draw from survey data collected from 94 experts attending the FAM. Respondents self-report the tendencies and aims they bring to the assessment (i.e. motivation), the type and amount of evidence they require for knowledge ...
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Alpha-Kurse für alle
(2019)
Unter Inklusiver Bildung verstehen wir hier den gemeinsamen Unterricht behinderter und nichtbehinderter Menschen. Die Teilnehmenden in Alphabetisierungskursen und in Kursen zum Nachholen von Schulabschlüssen (Zweiter Bildungsweg) sind sehr heterogen. Menschen unterschiedlichen Alters, Geschlechts, Herkunft etc. oder mit unterschiedlichen Beeinträchtigungen nehmen an diesen Kursen teil. Alle haben unterschiedliche Lernstände und Gründe für die Teilnahme am Kurs und somit auch unterschiedliche Bedarfe. Wie wird Inklusive ...
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Loving the mess: navigating diversity and conflict in social values for sustainability
(2019-08-24)
This paper concludes a special feature of Sustainability Science that explores a broad range of social value theoretical traditions, such as religious studies, social psychology, indigenous knowledge, economics, sociology, and philosophy. We introduce a novel transdisciplinary conceptual framework that revolves around concepts of ‘lenses’ and ‘tensions’ to help navigate value diversity. First, we consider the notion of lenses: perspectives on value and valuation along diverse dimensions that describe what values focus ...
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Characterization of polyamide 6.10 composites incorporated with microcrystalline cellulose fiber: Effects of fiber loading and impact modifier
(2018-08-14)
Microcrystalline cellulose (MCC) fiber‐reinforced polyamide 6.10 (PA) composites were prepared in the presence of an impact modifier (IM), exxelor VA1803 (VA), by melt compounding process. Fiber loading was considered from 20 to 30 wt.%, whereas IM was varied from 2.0 to 5.0 wt.%. Composites were characterized by tensile test, impact test, dynamic thermal mechanical analysis (DTMA), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and X‐ray diffraction (XRD). Composites’ fractured surfaces ...
Aufsatz
Fabrication and characterization of ethylene–octene copolymer composites with ionic liquid functionalized carbon nanotubes
(2017-10-16)
Modification of multi-walled carbon nanotubes (MWCNTs) by means of imidazolium ionic liquid (IL) was performed. Structural characterization of funtionalized nanofillers (IL-f-MWCNTs) was made by means of Raman spectroscopy and transmission electron microscopy. MWCNTs and IL-f-MWCNTs were introduced within ethylene octane copolymer (EOC) with octene co-monomer content of 17% by using the masterbatch approach. The efficiency of the carbonaceous nanofiller distribution within the polymer matrix was characterized by means ...