ABSTRACT. An updated compilation of published and new data of major-ion (Ca, Cl, K, Mg, Na, NO 3 , SO 4 ) and methylsulfonate (MS) concentrations in snow from 520 Antarctic sites is provided by the national ITASE (International Trans-Antarctic Scientific Expedition) programmes of Australia, Brazil, China, Germany, Italy, Japan, Korea, New Zealand, Norway, the United Kingdom, the United States and the national Antarctic programme of Finland. The comparison shows that snow chemistry concentrations vary by up to four orders of magnitude across Antarctica and exhibit distinct geographical patterns. The Antarctic-wide comparison of glaciochemical records provides a unique opportunity to improve our understanding of the fundamental factors that ultimately control the chemistry of snow or ice samples. This paper aims to initiate data compilation and administration in order to provide a framework for facilitation of Antarctic-wide snow chemistry discussions across all ITASE nations and other contributing groups. The data are made available through the ITASE web page (http:// www2.umaine.edu/itase/content/syngroups/snowchem.html) and will be updated with new data as they are provided. In addition, recommendations for future research efforts are summarized.
Abstract. The article presents overview of additive manufacturing for concrete structures. Study focuses on specific tests used to determine suitability of high performance mixes for 3D printing. The tests include determination of compressive strength and evaluation of printing speed, extrudability and overall surface quality. Tests were performed on a HighPerformance Concrete mix with fine natural aggregate up to 2 mm. Mineral additives such as silica fume and fly ash, and superplasticizer were added to obtain proper consistency. The tests were performed using specially designed site consisting of Cartesian robot and pumping module. The design of printed paths were tailored for specific tests. The evaluation of pump performance was made by measuring pumped mix volume in time. The determination of correct pumping speed was made based on the visual quality of the printed layers. Study determines also the ability to print multilayered structures and printability window of proposed mix.
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