21 research outputs found
M.A.D.:Media Art Database(s)and the Challenges of Taste, Evaluation, and Appraisal
No full textThis essay seeks to delineate the possible mutual benefits that different disciplines such as art history, media studies, computer science, etc. might derive from their specific efforts at formulating requirements and strategies for the appraisal of records and data as well as scientific and other concepts related to media art in its widest sense. In this context, the author presents the M.A.D. Media Art Database project as an information system at the disposal of media art and its history and theory, and as a network interface between archived material and knowledge. With its bottom-up structure, the M.A.D. database is proposed as a decisive motive force in assembling potent aggregates of knowledge and expertise
Gold particles from Kamchatka: a brief look at gold biogeochemical cycling in a distinct environment
No full textKamchatka is a peninsula located on the far eastern side of Russia and is a geologically active region within the Pacific Ring of Fire. Placer gold particles were obtained from a stream located in the Yelizovsky District and were compared to particles from regions at similar latitudes. Russian gold particle surface textures and morphologies were characterised optically and using electron microscopy, and bacteria occurring on the surface of particles were inferred from detected amplicon sequence variants (ASVs). The gold particles contained remarkably variable gold surface textures with an average 70% of surface area containing clay-filled concavities. Particle morphologies, interpreted from axis ratios, suggested that these particles were transported from primary sources. Proteobacteria constituted 60% of all the detected ASVs from the particles. Within this phylum, Gammaproteobacteria was the most dominant class. This study contributes to the understanding of gold biogeochemical cycling in a distinct bioclimatic environment.Maria Angelica D. Rea, Joël Brugger, Barbara Etschmann, Victor Okrugin and Jeremiah Shuste
Toxicity assessment of gold ions and gold nanoparticles to golden perch larvae (Macquaria ambigua)
No full textGolden perch (Macquaria ambigua) is a freshwater game-fish native to central and southeast Australia. Larvae of this fish species were used in two different types of experiments to evaluate the effects of short-term exposures (up to 6 days) to aqueous gold, 5 nm gold nanoparticles (AuNPs), or 50 nm AuNPs. Relative to the control, increased gold concentrations corresponded with yolk-sac edema (swelling). Larvae exposed to 50 μM of 5 nm AuNPs had yolk-sacs that were ~1.5 times larger resulting in the appearance of bent notochords. After two days of exposure, 100% mortality was observed. Total mortalities were <25% in the other larvae–gold systems, suggesting that these larvae can quickly adapt to the presence of gold. In terms of an oxidative stress response, the larvae from all systems did not express high enzymatic activity. The state of the gold determined how much could be taken up (or immobilised) by a larva. Aqueous gold and 5 nm AuNPs easily pass through cells; therefore, larvae exposed to these forms of gold contained the highest concentrations. Scanning electron microscopy confirmed that cells comprising the epithelium and fins contained AuNPs. Aqueous gold was reduced to nanometre-scale particles within cells. Comparatively, 5 nm AuNPs appeared to be aggregated within cells forming clusters hundreds of nanometres in size. On the contrary, 50 nm AuNPs were not observed within cells but were detected within larvae by (single particle) inductively coupled plasma mass spectroscopy, suggesting that these AuNPs were probably taken up through the mouth or gills. The results of the present study demonstrate that exposure to AuNPs had adverse effects on developing golden perch larvae. Additionally, these effects were dependent on the size of the AuNPs.Jeremiah Shuster, Maria A.D. Rea, Bhanu Nidumolu and Anupama Kuma
Textile reinforced double curved concrete elements
No full textThe construction of buildings with free-form concrete surfaces can be accompanied with relatively high costs due to the production of uniquely shaped curved concrete elements. Delft University of Technology researches a method to produce such elements in a cost-efficient way using a re-usable flexible mould. The method requires a flexible reinforcement type for the production of the concrete elements. In this Master’s thesis one of the options to reinforce elements produced with the flexible mould was researched: textiles. In the first part of this project experiments were conducted on the behavior of (ar-glass) textile reinforced concrete in the flexible mould and the mechanical properties of textile reinforced concrete. Additionally the load bearing behavior of textile reinforced concrete was modeled using the finite element method in ANSYS. The second part of the project consisted out of a case study on the application of textile reinforced concrete elements as cladding panels.Structural DesignStructural EngineeringCivil Engineering and Geoscience
Het negatieve effect van grote grazers op broedvogels
No full textDe begeleider en/of auteur heeft geen toestemming gegeven tot het openbaar maken van de scriptie.
The supervisor and/or the author did not authorize public publication of the thesis.
Author Correction: The European Reference Genome Atlas : piloting a decentralised approach to equitable biodiversity genomics
No full textIn the orginial version of this Article, the wrong affiliation was given for Maria Angela Diroma. It should be Department of Biology, University of Florence, Sesto Fiorentino, Italy. In addition, her contributions were also incorrect, they should have been “M.A.D. drafted a supplementary figure/box and reviewed the draft manuscript”. The HTML and PDF versions of the Article have been corrected
The use of SCC and textile reinforcement
No full textIn an earlier article (CPI issue of August 2011 [1]) a method was presented for producing precast curved panels with a thickness of a few centimeters using the 'flexible mould method'. This method is the central theme in the PhD study of the first author on the realization of freeform architecture in concrete. The concrete panels manufactured with the flexible mould method can be applied for many architectural purposes in which curvature is present, such as facade cladding, precast plank floors or roof elements. The method essentially comprises a reusable and bendable smooth surface that can be deformed into a wide range of geometries, including variable curvatures in one or two directions and freely shaped edge contours. In the earlier article in CPI it was concluded that some aspects needed further research, among which were the choice of suitable concrete mixtures and the investigation of fibre reinforcement. This article discusses the results of experiments investigating these aspects: the mixture choice was guided by measuring the workability in time and the ability to undergo deformations after casting without cracking. Furthermore, AR-glass textile was used to strengthen the panels with a flexible reinforcement that allowed deformation in the non-hardened state. Experimental work has been done to check the position of the reinforcement after deformation and the contribution of the textiles to the strength of the panels.Structural EngineeringCivil Engineering and Geoscience
Author Correction:The European Reference Genome Atlas: piloting a decentralised approach to equitable biodiversity genomics (npj Biodiversity, (2024), 3, 1, (28), 10.1038/s44185-024-00054-6)
No full textCorrection to: npj Biodiversityhttps://doi.org/10.1038/s44185-024-00054-6, published online 17 September 2024 In the orginial version of this Article, the wrong affiliation was given for Maria Angela Diroma. It should be Department of Biology, University of Florence, Sesto Fiorentino, Italy. In addition, her contributions were also incorrect, they should have been “M.A.D. drafted a supplementary figure/box and reviewed the draft manuscript”. The HTML and PDF versions of the Article have been corrected.</p
Production of Curved Precast Concrete Elements for Shell Structures and Free-form Architecture using the Flexible Mould Method
No full textFree-form buildings tend to be expensive. By optimizing the production process, economical and well-performing precast concrete structures can be manufactured. In this paper, a method is presented that allows producing highly accurate double curved-elements without the need for milling two expensive mould surfaces per single element. The flexible mould is fully reusable and the benefits of applying self-compacting concrete are utilised. The flexible mould process work as follows: Thin concrete panels are cast in a horizontally positioned flexible mould, using a selflevelling concrete. After a certain initial hardening, the mould is deformed and the concrete is allowed to harden further. The knowledge about rheological characteristics is essential during casting and to find the suitable moment for the mould to be deformed. The behaviour of the concrete in the plastic stage is important: A) to allow the concrete to follow the deformation of the flexible mould, B) to counteract its movement under a slope and C) to prevent cracking in an early phase. After the flexible mould has reached its final position, the concrete develops its strength and can be demoulded in a short production-cycle; aesthetically attractive elements of different and complex geometries can be produced with the same reusable mould.Structural EngineeringCivil Engineering and Geoscience
