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The Usage of Perlitic Pumice from İzmir-Menderes (Turkey) in the Production of Low-Strength Lightweight Concrete

100%
Ceylan H., Saraç S.
Acta Physica Polonica A
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2017
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vol. 132
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issue 3
667-669
EN
Lightweight aggregates, used to produce cavity blocks in the construction sector, vary according to their technical properties and thus, technical analyses should be performed on lightweight aggregate specimens. Lightweight aggregates, like pumice, are widely employed for the production of construction elements, used as light masonry units. In literature there are studies related to applications of various lightweight aggregates, such as volcanic slag, ignimbrite and expanded clay, in addition to pumice, to produce porous cavity blocks. This study investigates the usability of perlitic pumice formations, present around Menderes, İzmir (Turkey), as lightweight aggregate. Many experiments were conducted to investigate this possibility and to determine the optimum mixing ratios of aggregate. Based on the results, for 10% of cement by volume, the optimum aggregate mixing ratio was 40% 0-4 mm and 60% 4-8 mm.
2
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Direct and Postsynthetic Functionalization of Mesoporous B-SBA-15-SO₃H Acid Catalyst and Application to Methyl Propionate Esterification

100%
Erdem B., Azko Ç., Erdem S., Öksüzoğlu R.
Acta Physica Polonica A
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2017
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vol. 132
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issue 3
756-759
EN
Organic functionality can be added to mesoporous silicates in two ways: either by covalent grafting (postsynthetic) of various functional groups onto the channel walls or by incorporating functionalities directly during the synthesis (one-pot). If the grafted catalytically active groups experience similar environments and are isolated from each other, catalysis process is greatly facilitated. For this purpose, boric acid, as boron source, was added into the initial reaction mixture and then acid functionalization was performed by post and direct method. The obtained acid catalysts were tested in the esterification of propionic acid with methanol and the activity of these new materials was compared to that of SBA-15-SO₃H. Boron addition has facilitated the methyl propionate esterification for both postsynthetic and direct functionalized acid catalyst. Boron incorporated and postsynthetic functionalized mesoporous acid catalyst has highly enhanced the esterification reaction, compared to direct functionalized acid catalyst. The post functionalization method seems to be superior to one-pot functionalization method for preparation of mesoporous acid catalysts.
3
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Properties of Sound Panels Made from Recycled Footwear Treads

100%
Yildiz F., Parlar A., Parlar Z., Bakkal M.
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EN
Natural resources have been decreasing with the large expansion of the world's population. In order to supply raw material for production, new recycling approaches should be developed for waste materials. Worn shoes is one of the most common waste products that can be recycled for this purpose. According to the record, shoes are very complex products, as they can be produced from forty different materials, like leather, rubber, polymers etc. Especially the bottom layers of the shoes are made from sound absorbing materials like polyurethane, thermoplastic rubber and PVC. Because today's technology is not able to separate these materials from each other during recycling, they should be used in a homogenised state. Thus these parts were shredded into small granules and mixed. PU binder and hot press were used to obtain samples for tests. In this paper sound absorption, sound isolation, vibration isolation and thermal insulation properties of the tread mixture are investigated. In addition to that, the mechanical properties of the material were also investigated by measuring the compression strength of the material.
4
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Porosity of Silica Monoliths with Tailored Mesopores of Ink-Bottle Shape Determined by Nitrogen Adsorption and Positron Annihilation Lifetime Spectroscopy

64%
Sienkiewicz A., Kierys A., Gorgol M., Zaleski R.
Acta Physica Polonica A
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2017
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vol. 132
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issue 5
1568-1571
EN
The comparison of pore size distributions obtained with the use of two porosimetric methods: low temperature nitrogen sorption (LN2) and positron annihilation lifetime spectroscopy (PALS), was performed for porous silica monoliths. Four investigated samples were prepared under various synthesis conditions. Nitrogen sorption showed the presence of bottle-shaped pores in all investigated samples. In addition, it seems that the presence of methanol during synthesis influences porosity to a greater extent than organic additives. Quite good agreement between the LN2 and PALS results was observed only for the silica monolith synthesized with β-cyclodextrins as pore directing agent. The biggest discrepancy in the results obtained from these two techniques was observed for the silica gel synthesized with no additives. The origin of such discrepancies, taking into account the shape of pore size distribution and deficiencies of data analysis techniques, is discussed.
5
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Effects of Pre-Forming Process and PVC Foam Reinforcement on the Deformation Behavior of Aluminum Tube under Axial Loading

52%
Ekşi S., Kaptı A., Genel K.
Acta Physica Polonica A
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2017
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vol. 132
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issue 3
875-878
EN
In this study, the effects of pre-forming and foam reinforcement on the axial compression behavior of circular thin-walled aluminum tubes were experimentally investigated. Compression tests were performed in a computer controlled test machine at the cross-head speed of 1 mm/s. Pre-forming has changed the folding behavior of tube and increased the energy absorbing capacity 1.26 times that of empty tube. The PVC reinforcement has increased the energy absorbing capacity 1.22 times. PVC reinforcement increases the stability of tube wall deformation; hence it positively affects the energy absorption. The energy absorbing capacity of pre-formed and PVC foam reinforced tubes increase approximately 1.4 times that of empty tube. It was however shown that the reinforcement and pre-forming had no significant effect on the maximum load.
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