43892
2018
eng
13
22
129
article
Elsevier Science
1
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Monitoring microbial soiling in photovoltaic systems: A qPCR-based approach
Soiling of photovoltaic (PV) systems compromises their performance causing a significant power loss and demanding periodical cleaning actions. This phenomenon raises great concerns in the solar energy field, thus leading to notable research efforts over the last decades. Soiling is caused by a dual action of dust deposition and biofouling. However, surprisingly, the microbiological contribution to PV soiling is often overlooked or underestimated. In this study, a variety of qPCR-based methods have been developed to quantify the microbial load of fungi, bacteria and phototrophs on PV panels. These protocols were evaluated by comparison with culturedependent methods, and were implemented with real solar plants for two years. The results show that the developed molecular methods are highly sensitive and reliable to monitor the microbial component of the soiling. Fungal biomass was clearly dominant in all analysed PV modules, while bacteria and phototrophs showed much lower abundance. Light microscopy and qPCR results revealed that melanised microcolonial fungi and phototrophs are the main biofilm-forming microorganisms on the studied solar panels. In particular, the fungal qPCR protocol is proposed as a useful tool for monitoring of PV soiling, and investigating the microbial contribution to specific soiling cases.
International Biodeterioration & Biodegradation
10.1016/j.ibiod.2017.12.008
0964-8305
26.04.2018
Pedro Maria Martin-Sanchez
Christopher Gebhardt
Jörg Toepel
J. Barry
N. Munzke
Jens Günster
Anna Gorbushina
eng
uncontrolled
Solar panels
eng
uncontrolled
PV modules
eng
uncontrolled
Real-time qPCR
eng
uncontrolled
Bacteria
eng
uncontrolled
Fungi
eng
uncontrolled
Phototrophs
Sanitär- und Kommunaltechnik; Umwelttechnik
4 Material und Umwelt
5 Werkstofftechnik
5.4 Multimateriale Fertigungsprozesse
Energie
Umwelt
Umwelt-Material-Interaktionen
Verlagsliteratur
Datei im Netzwerk der BAM verfügbar ("Closed Access")
4.0 Abteilungsleitung und andere
44157
2018
eng
1298
1307
3
42
article
Wiley & Sons, Ltd.
1
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Sand erosion of solar glass: Specific energy uptake, total transmittance, and module efficiency
Surface roughness, R Z , normal transmittance, Τ N , total transmittance, Τ T , and photovoltaic (PV) module efficiency, η S , were measured for commercial solar glass plates and PV test modules identically sandblasted with different loads of quartz sand (200 – 400 μ m), impact inclination angles, and sand particle speed. Measured data are presented versus the specific energy uptake during sand blasting, E (J/m2). Cracks, adhering particles, and scratch ‐ like textures probably caused by plastic flow phenomena could be observed after sand blasting. Their characteristic size was much smaller than that of sand particles.
After blasting and subsequent cleaning, the glass surface was still covered with adhering glass particles. These particles, cracks, and scratch ‐ like textures could not be removed by cleaning. For sand blasting with α = 30° inclination angle and E = 30 000 J/m2, normal transmittance, total transmittance, and relative module efficiency decreased by 29%, 2% and ∽ 2%, respectively. This finding indicates that diffusive transmission of light substantially contributes to PV module efficiency and that the module efficiency decrease caused by sand erosion can be better estimated from total than by normal transmittance measurements.
International Journal of Energy Research
10.1002/er.3930
1099-114X
0363-907X
01.03.2018
Boris Agea Blanco
Christian Meyer
Ralf Müller
Jens Günster
eng
uncontrolled
Transmittance
eng
uncontrolled
Efficiency
eng
uncontrolled
Photovoltaic modules
eng
uncontrolled
Roughness
eng
uncontrolled
Sand blasting
Angewandte Physik
5 Werkstofftechnik
5.4 Multimateriale Fertigungsprozesse
5.6 Glas
Energie
Verlagsliteratur
Datei im Netzwerk der BAM verfügbar ("Closed Access")
45718
2018
eng
1960
1971
14
33
article
Cambridge University Press
1
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Bioactive glass-ceramic scaffolds by additive manufacturing and sinter-crystallization of fi ne glass powders
Wollastonite (CaSiO 3 ) – diopside (CaMgSi 2 O 6 ) glass-ceramic scaffolds have been successfully fabricated using two different additive manufacturing techniques: powder-based 3D printing (3DP) and digital light processing (DLP), coupled with the sinter-crystallization of glass powders with two different compositions. The adopted manufacturing process depended on the balance between viscous flow sintering and crystallization of the glass particles, in turn in fluenced by the powder size and the sensitivity of CaO – MgO – SiO 2 glasses to surface nucleation. 3DP used coarser glass powders and was more appropriate for low temperature firing (800 – 900 °C), leading to samples with limited crystallization. On the contrary, DLP used finer glass powders, leading to highly crystallized glass-ceramic samples. Despite the differences in manufacturing technology and crystallization, all samples featured very good strength-to-density ratios, which bene fit theiruse for bone tissue engineering applications. The bioactivity of 3D-printed glass-ceramics after immersion in simulated body fluid and the similarities, in terms of ionic releases and hydroxyapatite formation with already validated bioactive glass-ceramics, were preliminarily assessed.
Journal Materials Research
2044-5326
0884-2914
10.1557/jmr.2018.120
15.08.2018
H. Elsayed
Andrea Zocca
J. Schmidt
Jens Günster
P. Colombo
E. Bernardo
eng
uncontrolled
3D-Printing
eng
uncontrolled
Bio Ceramic
eng
uncontrolled
Additive manufacturing
Ingenieurwissenschaften und zugeordnete Tätigkeiten
5 Werkstofftechnik
5.4 Multimateriale Fertigungsprozesse
Material
Verlagsliteratur
Datei im Netzwerk der BAM verfügbar ("Closed Access")
Additive Fertigung
45713
2018
eng
3395
3400
9
38
article
Elsevier Ltd.
1
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3D printing of porcelain by layerwise slurry deposition
The Layerwise Slurry Deposition is a technology for the deposition of highly packed powder layers. A powder bed is achieved by depositing and drying layers of a ceramic suspension by means of a doctor blade. This deposition technique was combined with the binder jetting technology to develop a novel Additive Manufacturing technology, named LSD-print. The LSD-print was applied to a porcelain ceramic. It is shown that it was possible to produce parts with high definition, good surface finish and at the same time having physical and mechanical properties close to those of traditionally processed porcelain, e.g. by slip casting.
This technology shows high future potential for being integrated alongside traditional production of porce-lain, as it is easily scalable to large areas while maintaining a good definition. Both the Layerwise Slurry Deposition method and the binder jetting technologies are readily scalable to areas as large as > 1 m2.
Journal of the European Ceramic Society
0955-2219
10.1016/j.jeurceramsoc.2018.03.014
15.08.2018
Jens Günster
Andrea Zocca
Pedro Lima
W. Acchar
eng
uncontrolled
Binder jetting
eng
uncontrolled
Additive Manufacturing
eng
uncontrolled
3D printing
eng
uncontrolled
Porcelain
Ingenieurwissenschaften und zugeordnete Tätigkeiten
5 Werkstofftechnik
5.4 Multimateriale Fertigungsprozesse
Material
Verlagsliteratur
Datei im Netzwerk der BAM verfügbar ("Closed Access")
Additive Fertigung
45714
2018
eng
1800003-1
1800003-7
5
3
article
Wiley-VCH
Weinheim
1
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3D Printing of Self-Organizing Structural Elements for Advanced Functional Structures
A shape evolution approach based on the thermally activated self-organization of 3D printed parts into minimal surface area structures is presented. With this strategy, the present communication opposes currently established additive manufacturing strategies aiming to stipulate each individual volumetric element (voxel) of a part. Instead, a 3D structure is roughly defined in a 3D printing process, with all its advantages, and an externally triggered self-organization allows the formation of structural elements with a definition greatly exceeding the volumetric resolution of the printing process. For enabling the self-organization of printed objects by viscous flow of material, functionally graded structures are printed as rigid frame and melting filler. This approach uniquely combines the freedom in design, provided by 3D printing, with the mathematical formulation of minimal surface structures and the knowledge of the physical potentials governing self-organization, to overcome the paradigm which strictly orrelates the geometrical definition of 3D printed parts to the volumetric resolution of the printing process. Moreover, a transient liquid phase allows local programming of functionalities, such as the alignment of functional particles, by means of electric or magnetic fields.
Advanced Materials Technologies
10.1002/admt.201800003
2365-709X
15.08.2018
Jinchun Chi
Andrea Zocca
Boris Agea Blanco
J. Melcher
M. Sparenberg
Jens Günster
eng
uncontrolled
Additive Manufacturing
eng
uncontrolled
Self-Assembly
eng
uncontrolled
3D-Printing
eng
uncontrolled
Polymeric Materials
Ingenieurwissenschaften und zugeordnete Tätigkeiten
5 Werkstofftechnik
5.4 Multimateriale Fertigungsprozesse
Material
Verlagsliteratur
Datei im Netzwerk der BAM verfügbar ("Closed Access")
Additive Fertigung
45715
2018
eng
37
41
1
9
article
Göller Verlag
76532 Baden-Baden
1
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Manufacturing of SiO2-Coated b-TCP Structures by 3D Printing using a Preceramic Polymer as Printing Binder and Silica Source
Tricalcium phosphate (b-TCP) can be used as bone graft, exhibiting suitable bioabsorption and osteoconduction properties. The presence of silica may induce the formation of a hydroxyapatite layer, enhancing the integration between implant and bone tissue. Preceramic polymers present silicon in their composition, being a source of SiO2 after thermal treatment. Using the versatility of 3D printing, b-TCP and a polysiloxane were combined to manufacture a bulkb-TCP with a silica coating. For the additive manufacturing process, PMMA powder was used as passive binder for the b-TCP particles, and polymethylsilsesquioxane (MK), dissolved in an organic solvent, was used both as a printing binder (ink) and as the source of SiO2 for the coating. Five distinct coating compositions were printed with increasing amounts of MK. The structures were then submitted to heat treatment at 1180 °C for 4 h. XRD and FTIR showed no chemical reaction between the calcium phosphate and silica. SEM allowed observation of a silicon-based ating on the structure surface. Mechanical strength of the sintered porous structures was within the range of that of trabecular bones.
Journal Ceramic Science Technology
10.4416/JCST2017-00056
15.08.2018
R. Bernardino
C. Wirth
S.L. Stares
G.V. Salmoria
D. Hotza
Jens Günster
eng
uncontrolled
Tricalcium Phosphate
eng
uncontrolled
3D-Printing
eng
uncontrolled
Preceramic polymer
eng
uncontrolled
Bone regeneration
Ingenieurwissenschaften und zugeordnete Tätigkeiten
5 Werkstofftechnik
5.4 Multimateriale Fertigungsprozesse
Material
Verlagsliteratur
Datei im Netzwerk der BAM verfügbar ("Closed Access")
Additive Fertigung
46612
2018
eng
e0204025, 1
7
10
13
article
Public Library of Science
San Francisco, Kalifornien, Vereinigte Staaten
1
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Towards the colonization of Mars by in-situ resource utilization: Slip cast ceramics from Martian soil simulant
Here we demonstrate that by applying exclusively Martian resources a processing route involving suspensions of mineral particles called slurries or slips can be established for manufacturing ceramics on Mars. We developed water-based slurries without the use of additives that had a 51 wt. % solid load resembling commercial porcelain slurries in respect to the particle size distribution and rheological properties. These slurries were used to slip cast discs, rings and vases that were sintered at temperatures between 1000 and 1130 °C using different sintering schedules, the latter were set-up according the results of hot-stage microscopic characterization. The microstructure, porosity and the mechanical properties were characterized by SEM, X-ray Computer tomography and Weibull analysis. Our wet processing of minerals yields ceramics with complex shapes that show similar mechanical properties to porcelain and could serve as a technology for future Mars colonization. The best quality parts with completely vitrificated matrix supporting a few idiomorphic crystals are obtained at 1130 °C with 10 h dwell time with volume and linear shrinkage as much as ~62% and ~17% and a characteristic compressive strength of 51 MPa.
Plos One
1932-6203
10.1371/journal.pone.0204025
16.11.2018
D. Karl
F. Kamutzki
Andrea Zocca
O. Görke
Jens Günster
A. Gurlo
eng
uncontrolled
Ceramic
eng
uncontrolled
Mars
Ingenieurwissenschaften und zugeordnete Tätigkeiten
5 Werkstofftechnik
5.4 Multimateriale Fertigungsprozesse
Material
Verlagsliteratur
Datei im Netzwerk der BAM verfügbar ("Closed Access")
46035
2018
eng
poster
0
--
--
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Bioceramics from Ca3(PO4)2 - CaKPO4 - CaNaPO4 system for bone replacement and grafting
Biomaterials for bone replacement and grafting should possess sufficient strength, be bioresorbable and demonstrate osteoconductivity/osteoinductivity. Nowadays, hydroxyapatite (HA) and tricalcium phosphate (TCP) are the most widespread ceramics for bone grafting at the market, however, their resorption is reported, in some cases, to be not enough. This is why the search for more soluble ceramics compared to HA and TCP looks rather viable.
A possible way to increase ceramics solubility leads to partial substitution of Ca2+-ions in Ca3(PO4)2 by alkali castions, like Na+ or/and K+. Improvement of solubility stems from decreasing lattice energy of a substituted phase, as well as increase in hydration energy of the ions releasing from the phase to ambient solution. From this viewpoint, bioceramics based on compositions from Ca3(PO4)2 - CaKPO4 - CaNaPO4 ternary system seems to be prospective for bone replacement and grafting in sense of resorption properties. At the same time, one should bear in mind that solubility level (resorbability) is governed not only by reduction of lattice energy, but also by microstructure features. Grain sizes and porosity contribute much to dissolution rate making study of sintering of aforementioned ceramics highly important.
Biomaterials and Novel Technologies for Healthcare, 2nd International Biennial Conference BioMaH
Frascati (Rome), Italy
08.10.2018
11.10.2018
Nikolai Orlov
P. Milkin
P Evdokimov
V. Putlayev
Jens Günster
Dagmar Nicolaides
eng
uncontrolled
Bio Ceramics
eng
uncontrolled
Bioresorbable
Ingenieurwissenschaften und zugeordnete Tätigkeiten
5 Werkstofftechnik
5.4 Multimateriale Fertigungsprozesse
Material
Degradation von Werkstoffen
Datei im Netzwerk der BAM verfügbar ("Closed Access")
Präsentation