38 research outputs found
3D-measurements of 3D-deformations of pantographic structures
No full textSamples of differently sized so-called pantographic structures are subjected to large deformation loading tests up to rupture, while their response to the deformation is recorded by an optical 3D-measurement system. Digital image correlation is used to calculate the deformation that took place perpendicular to the reference plane by the help of a four-camera system. Results show that the deformation behavior is strongly non-linear and that the structures are capable to perform large (elastic) deformations without leading to complete failure
The macroscopic behavior of pantographic sheets depends mainly on their microstructure: experimental evidence and qualitative analysis of damage in metallic specimens
No full textRecently the exotic properties of pantographic metamaterials have been investigated, and various mathematical models (both discrete and continuous) have been introduced. However, the experimental evidence available up to now concerns only polyamide specimens. In this paper, we use specimens printed using metallic powder. We prove experimentally that the main qualitative and quantitative features of pantographic sheets in planar deformation are independent of the constituting materials, at least when they can be regarded as homogeneous and isotropic at micro-level. Of course, the absolute value of Young’s modulus of constituent material affects the overall reaction force needed to the hard device to impose a given displacement: A first investigation on this effect is also attempted
Bioethanol fermentation of Jerusalem artichoke using mixed culture of Saccharomyces cerevisiae and Kluyveromyces marxianus
No full textEffects of mixed cultures of Saccharomyces cerevisiae Levuline FB — higher ethanol tolerance — and different Kluyveromyces strains — higher inulinase activity — on the production of ethanol from Jerusalem artichoke extract were investigated. Among the investigated strains, combination of S. cerevisiae and K. marxianus strain Y00959 with simultaneous saccharification and fermentation gave the best efficiency (76%) of bioconversion. The optimal ratio of mixed cultures was determined to be 1:1 of K. marxianus and S. cerevisiae. Central composite design (CCD) was adapted to find the optimum initial substrate concentration and inoculum size for the maximal production of ethanol from Jerusalem artichoke juice. The optimum fermentation conditions were found to be 24% (m/w) substrate concentration and 45 OD600nm ml/100 ml inoculum size of mixed culture. Use of these conditions, about 10.67% (v/v) was produced at 148 h of alcoholic fermentation given. Results of this work provide benefits of mixed culture on production of bioethanol from Jerusalem artichoke
Thermophilic Fungus Thermomyces lanuginosus: Current Review on Potential Source for Thermostable Enzymes
No full textThermomyces lanuginosus is a real thermophilic fungus and can be isolated
worldwide from various substances mainly from compost or soil, thus it is able to
grow and utilise numerous complex and natural substrates. This fungus have been
reported to produce of high levels of different enzymes (cellulase-free xylanase,
lipase, amylolytic enzymes, galactosidases etc.) that are stable up to 60-70 oC for
several hours in broad range of pH. These enzymes are appearing to be more
thermostable than similar ones from mesophilic fungi. X-ray crystal structures of
lipase, xylanase and fatty acid synthase (multienzyme system) from T. lanuginosus
now are available in Protein Database Bank. The catalytic triad in active centre of
lipase was formed like one from serine protease and is secluded by an α-helical lid.
The presence of extra disulfide bridge in structure of xylanase from T. lanuginosus
might contribute to thermostability of it. The genes coding xylanase (XylA) or
phytase (PhyA) have been cloned and expressed in other protein expression
systems, thus giving opportunity to discover and explorer genetical background of
T. lanuginosus. Due to intensive development by Novozymes A/S, lipase produced
by this fungus is commercially available in two forms: soluble form known as
Lipolase® and immobilised form as Lipozyme®. Overall, thermophilic fungus T.
lanuginosus has high potential to be good source for production of thermostable
enzymes having significant important in biotechnology
Bioethanol fermentation of Jerusalem artichoke using mixed culture of Saccharomyces cerevisiae and Kluyveromyces marxianus
No full textEffects of mixed cultures of Saccharomyces cerevisiae Levuline FB — higher ethanol tolerance — and different Kluyveromyces strains — higher inulinase activity — on the production of ethanol from Jerusalem artichoke extract were investigated. Among the investigated strains, combination of S. cerevisiae and K. marxianus strain Y00959 with simultaneous saccharification and fermentation gave the best efficiency (76%) of bioconversion. The optimal ratio of mixed cultures was determined to be 1:1 of K. marxianus and S. cerevisiae. Central composite design (CCD) was adapted to find the optimum initial substrate concentration and inoculum size for the maximal production of ethanol from Jerusalem artichoke juice. The optimum fermentation conditions were found to be 24% (m/w) substrate concentration and 45 OD600nm ml/100 ml inoculum size of mixed culture. Use of these conditions, about 10.67% (v/v) was produced at 148 h of alcoholic fermentation given. Results of this work provide benefits of mixed culture on production of bioethanol from Jerusalem artichoke
Developing Tungsten-Filled Metal Matrix Composite Materials Using Laser Powder Bed Fusion
No full textArt. 8869, 10 S.The additive manufacturing technique laser powder bed fusion (L-PBF) opens up potential to process metal matrix composites (MMCs) with new material pairings free from limitations of conventional production techniques. In this work, we present a study on MMC material development using L-PBF. The generated composite material is composed of an X3NiCoMoTi 18-9-5 steel as matrix and spherical tungsten particles as filler material. A Design of Experiment (DoE)-based process parameter adaption leads to an Archimedean density close to the theoretical density in the case of 60 vol% tungsten content. A maximum ultimate tensile strength of 836 MPa is obtained. A failure analysis reveals a stable bonding of the tungsten particles to the steel matrix. This encourages the investigation of further material combinations. An additional heat treatment of the MMC indicates the potential to design specific material properties; it also highlights the complexity of such treatments.10Nr.2
The Influence of Subcritical Annealing and Cold Working on the Hydrogen Embrittlement Susceptibility of X65 D Pipeline Steel
No full textThis study investigated the effect of subcritical heat treatment and cold work on the hydrogen embrittlement (HE) susceptibility of the X65 D pipeline steel, representative of the Dampier-Bunbury Natural Gas Pipeline (DBNGP). Specimens were subjected to sub-critical annealing at 200°C, 400°C, or 600°C for 2 h or cold drawn to 5% reduction in area. Linearly increasing stress tests (LISTs) indicated subcritical annealing reduced strength and increased ductility, while cold working increased strength and decreased ductility. Hydrogen charging reduced the ductility of all specimens. Both subcritical annealing and cold working decreased somewhat the degree of HE. This was attributed to both treatments stabilising the dislocation distribution which possibly reduced the severity of hydrogen-enhanced localised plasticity (HELP). The novelty of this study lies in the evaluation of practical production changes and their influence on the HE of this steel.Full Tex
NaturalMSEQueries - A natural way to query Materials Science Engineering data experiments
No full textMaterials science experiments involve complex data that are often very heterogeneous and challenging to reproduce. This was observed, for example, in a previous study on harnessing lightweight design potentials via the Materials Data Space [3] for which the data from materials sciences engineering experiments were generated using linked open data principles [1,2], e.g., Resource Description Framework (RDF) as the standard model for data interchange on the Web. However, detailed knowledge of formulating questions in the query language SPARQL is necessary to query the data. A lack of knowledge in SPARQL to query data was observed by domain experts in materials science.
With this work, we aim to develop NaturalMSEQueries an approach for the material science domain expert where instead of SPARQL queries, the user can develop expressions in natural language, e.g., English, to query the data. This will significantly improve the usability of Semantic Web approaches in materials science and lower the adoption threshold of the methods for the domain experts. We plan to evaluate our approach, with varying amounts of data, from different sources. Furthermore, we want to compare with synthetic data to assess the quality of the implementation of our approach.
References
[1] T Berners-Lee, J Hendler, O Lassila - Scientific American, 2001, 284, 34–43.
[2] RDF specification. 2023. available at: https://www.w3.org/RDF/
[3] Huschka M, Dlugosch M, Friedmann V, Trelles EG, Hoschke K, Klotz UE, Patil S, Preußner J, Schweizer C, Tiberto D. The “AluTrace” Use Case: Harnessing Lightweight Design Potentials via the Materials Data Space®
Tectonics and geology of porphyry Cu-Au deposits along the Eastern Sunda Magmatic Arc, Indonesia
No full textThe discovery of the world-class Cu-Au deposit at Tumpangpitu, East Java (1.9 Gt @ 0.45% Cu, 0.45 g/t Au), has reinforced the eastern Sunda arc as a significant metallogenic belt that is highly promising for the discovery of major porphyry deposits. The arc hosts three premier porphyry Cu-Au deposits at Batu Hijau, Elang, and Tumpangpitu (>300 t Au and >5 Mt Cu). These giant porphyry deposits are confined to the eastern segment of the eastern Sunda arc (eastern Java to Sumbawa), constructed on island-arc crust where the Roo Rise is being subducted. By contrast, major epithermal (low-sulfidation dominant) deposits associated with poorly endowed porphyry prospects occur along the western segment of the arc (western Java), developed on thick continental crust on the southern margin of Sundaland associated with subduction of typically thin Indian oceanic crust.Porphyry Cu-Au deposits of the eastern Sunda arc are spatially associated with small, nested, dioritic to tonalitic intrusive complexes with low-K calc-alkaline to weakly alkaline signatures. Hypogene alteration and mineralization developed during three main temporally and spatially overlapping events, termed early, transitional, and late. The hypogene Cu-Au mineralized zone of the giant deposits forms a bell-shaped body of 0.3% Cu shell greater than 1 km in both diameter and vertical extent that is centered on multiphase, elongate, pencil-like tonalite intrusions, 200 to 1,200 m in diameter and >2 km vertical extent. Large (>20 km2) lithocaps associated with high-sulfidation epithermal systems and postporphyry mineralization diatreme breccias characterize productive porphyry districts at Batu Hijau, Elang, and Tumpangpitu. The known porphyry deposits with metal content exceeding 300 t Au and >5 Mt Cu all formed later than 5 Ma, suggesting an important change in the metallogeny of the arc at this time. These giant porphyry deposits formed relatively rapidly, typically over a period of 30 to 860 k.y. during the Pliocene-Pleistocene, between 5 and 2.5 Ma.Porphyry deposits along the eastern Sunda arc display characteristic geologic features similar to porphyry deposits elsewhere. Significant differences include low-K systems, dominance of hydrothermal biotite over K-feldspar, early intense actinolite alteration associated with ore, widespread shreddy chlorite after secondary biotite, narrow quartz-sericite-pyrite alteration zones, lack of development of chalcopyrite veins, large overlying lithocaps, and abundant chalcocite-bornite-covellite veinlets associated with late overprinting epithermal systems. Hydrothermal oligoclase is also more abundant than K-feldspar in the central biotite-magnetite zones.</p
