On-site pXRF analysis of glaze composition and colouring agents of “Iznik” tiles at Edirne mosques (15th and 16th-centuries)

The production of the tiles in Ottoman Empire had begun as a continued workshop of Seldjuk ceramic art, and after this initial phase, its own technology was introduced into Ottoman art by local craftsmen. Iznik tiles are among the most appreciated pottery masterpieces, and wall decoration in tiles is a significant asset of Unesco World Heritage Edirne mosques. Rare glaze composition studies have been made, which justify the need for more comprehensive studies. We present here the first on-site elemental analyses performed with portable XRF instrument in four of the most representative mosques in Edirne (?ah Melek Pa?a (1429), Muradiye (1435–1436), Üç ?erefeli (1410–1447) and Selimiye (1569–1575)). A handheld 785?nm Raman spectrometer was used as a complementary technique to identify some pigments. About forty tiles have been analysed in this research. Additionally, two tiles from Ye?ilce Mosque (1442, Edirne) have been analysed at the Selimiye Foundation Museum. The weight percent of the elements measured with pXRF are normalized by Si amount in order to eliminate the variation due to the positioning shifts. Different glazing technologies are evidenced (Master of Tabriz Sn-free glazed tiles, Hünkar Mahfili Sn-poor glazed tiles, and Sn-(Bi) rich ones). At least three different cobalt ores have been used (with characteristic Cu, Ni, Mn and Bi content) in blue decors. Use of a chromium-based ore is demonstrated for some Selimiye Hünkar Mahfili tiles. The link between ?ah Melek Pa?a and polychrome (mihrab) Muradiye tiles and Seldjuk production is established. On the contrary, the technology of Üç ?erefeli and blue-and-white Muradiye tiles is unique and appears a precursor of 16th-century Iznik production. Bismuth, Sn/Pb, Co/Mn, and Co/Ni ratio appears very useful to compare the different glazes and to identify mining sources of cobalt.     

Multimodal concept detection in broadcast media: KavTan

Concept detection stands as an important problem for efficient indexing and retrieval in large video archives. In this work, the KavTan System, which performs high-level semantic classification in one of the largest TV archives of Turkey, is presented. In this system, concept detection is performed using generalized visual and audio concept detection modules that are supported by video text detection, audio keyword spotting and specialized audio-visual semantic detection components. The performance of the presented framework was assessed objectively over a wide range of semantic concepts (5 high-level, 14 visual, 9 audio, 2 supplementary) by using a significant amount of precisely labeled ground truth data. KavTan System achieves successful high-level concept detection performance in unconstrained TV broadcast by efficiently utilizing multimodal information that is systematically extracted from both spatial and temporal extent of multimedia data.     

Skeleton-based edge bundling for graph visualization

In this paper, we present a novel approach for constructing bundled layouts of general graphs. As layout cues for bundles, we use medial axes, or skeletons, of edges which are similar in terms of position information. We combine edge clustering, distance fields, and 2D skeletonization to construct progressively bundled layouts for general graphs by iteratively attracting edges towards the centerlines of level sets of their distance fields. Apart from clustering, our entire pipeline is image-based with an efficient implementation in graphics hardware. Besides speed and implementation simplicity, our method allows explicit control of the emphasis on structure of the bundled layout, i.e. the creation of strongly branching (organic-like) or smooth bundles. We demonstrate our method on several large real-world graphs.     

Deconfinement leads to changes in the nanoscale plasticity of silicon

Silicon crystals have an important role in the electronics industry, and silicon nanoparticles have applications in areas such as nanoelectromechanical systems, photonics and biotechnology. However, the elastic-plastic transition observed in silicon is not fully understood; in particular, it is not known if the plasticity of silicon is determined by dislocations or by transformations between phases. Here, based on compression experiments and molecular dynamics simulations, we show that the mechanical properties of bulk silicon and silicon nanoparticles are significantly different. We find that bulk silicon exists in a state of relative constraint, with its plasticity dominated by phase transformations, whereas silicon nanoparticles are less constrained and display dislocation-driven plasticity. This transition, which we call deconfinement, can also explain the absence of phase transformations in deformed silicon nanowedges. Furthermore, the phenomenon is in agreement with effects observed in shape-memory alloy nanopillars, and provides insight into the origin of incipient plasticity.     

Direct numerical simulation of pipe flow using a solenoidal spectral method

In this study, a numerical method based on solenoidal basis functions, for the simulation of incompressible flow through a circular–cylindrical pipe, is presented. The solenoidal bases utilized in the study are formulated using the Legendre polynomials. Legendre polynomials are favorable, both for the form of the basis functions and for the inner product integrals arising from the Galerkin-type projection used. The projection is performed onto the dual solenoidal bases, eliminating the pressure variable, simplifying the numerical approach to the problem. The success of the scheme in calculating turbulence statistics and its energy conserving properties is investigated. The generated numerical method is also tested by simulating the effect of drag reduction due to spanwise wall oscillations.     

Utilization of Olive-Pomace Oil for Enzymatic Production of Cocoa Butter-like Fat

Refined olive-pomace oil (ROPO) was utilized as a source for the production of a cocoa butter (CB)-like fat. Immobilized sn-1,3 specific lipase-catalyzed acidolysis of ROPO with palmitic (PA) and stearic (SA) acids was performed at various substrate mole ratios (ROPO:PA:SA) to produce major triacylglycerols (TAGs) of CB. Products obtained for various substrate mole ratios were compared to a commercial CB in terms of TAG content, melting profile, solid fat content (SFC) and microstructure. The fat produced at a substrate mole ratio of 1:2:6 was the most similar to CB. The product contained 11% POP, 21.8% POS, 15.7% SOS while commercial CB contained 18.9% POP, 33.1% POS and 24.7% SOS. The product had a melting peak of 29.9 °C while CB had one of 28.5 °C. Polarized light microscope (PLM) images showed that fat crystal network microstructures of this product and CB were very similar.     

Overview of Poly(lactic acid) (PLA) fibre

Poly(lactic acid) (PLA) is an aliphatic polyester which can be derived from 100% renewable resources. PLA fibres can be dyed with disperse dyes, just like PET fires, although a modifid wet processing processes are employed. A variety of wet processing applications (pretreatment, dyeing, clearing, and subsequent finishing treatments) that imparts the greatest chemical and physical effect on the PLA fires necessitate major attention. Part II of this review reviews the wet processing (pretreatment, dyeing, clearing, subsequent finishing treatments, washing etc.) of PLA fibre and its effects on the fibre. This was accomplished through a broad literature survey including recent research and development in the area.     

Experimental observation of the effect of cleansing agents on the performance of polymer electrolyte fuel cells

Regular maintenance/cleaning of fuel pipeline and system hardware is an essential requirement in fuel cell operation to prevent contamination. An experimental and analytical study is performed to aid the selection of appropriate cleansers to be used as cleaning agents in polymer electrolyte fuel cell (PEFC). Screening tests for several cleansers are carried out during the injection of samples into the PEFC cathode inlet. One proper agent (naphtha) has shown a fully recoverable and minimal effect on the fuel cell performance and as such is determined as the best cleansing agent. Unlike other samples, naphtha does not contain any metallic components such as sodium or potassium in its composition. Furthermore, PEFC can still operate at ～0.4 V at constant current (1 A/cm²) even with a considerable flow rate (250 μl/min) of the selected cleanser. Detailed analytical analysis of this cleanser is provided by curve fitting the electrochemical impedance spectroscopy data, and evaluation of binary gas diffusion coefficients. It is indicated that performance loss during naphtha exposure is mainly due to the adsorption of contaminants on active Pt sites and an increase in mass transfer resistance.