The digital agenda of virtual currencies: Can BitCoin become a global currency?

This paper identifies and analyzes BitCoin features which may facilitate BitCoin to become a global currency, as well as characteristics which may impede the use of BitCoin as a medium of exchange, a unit of account and a store of value, and compares BitCoin with standard currencies with respect to the main functions of money. Among all analyzed BitCoin features, the extreme price volatility stands out most clearly compared to standard currencies. In order to understand the reasons for such extreme price volatility, we attempt to identify drivers of BitCoin price formation and estimate their importance econometrically. We apply time-series analytical mechanisms to daily data for the 2009–2014 period. Our estimation results suggest that BitCoin attractiveness indicators are the strongest drivers of BitCoin price followed by market forces. In contrast, macro-financial developments do not determine BitCoin price in the long-run. Our findings suggest that as long as BitCoin price will be mainly driven by speculative investments, BitCoin will not be able to compete with standard currencies.     

Bovine serum albumin gel/polyelectrolyte complex of hyaluronic acid and chitosan based microcarriers for Sorafenib targeted delivery

The development of systems for targeted delivery of Sorafenib in unresectable hepatocellular carcinoma to reduce the systemic toxicity is a challenge. In our article, we successfully prepared core-shell microcapsules based on bovine serum albumin gel with polyelectrolyte complex multilayer shell of polysaccharides with opposite charges, hyaluronic acid, and chitosan, encapsulating Sorafenib, as targeting delivery system for improved hepatocellular carcinoma therapy. A bovine serum albumin gel core was formed by a method based on a sacrificial CaCO₃ template, followed by the multilayer shell build-up of Ca²⁺ cross-linked hyaluronic acid hydrogel, and subsequently alternating multilayers of the polyelectrolyte complex formed between hyaluronic acid and chitosan. The following techniques: Fourier-transform infrared and UV–Vis spectroscopy, X-ray diffraction, differential scanning calorimetry, confocal laser scanning microscopy, atomic force microscopy, and scanning electron microscopy were used for the physicochemical characterization. These tests revealed the spherical shape of core-shell type, the micro-size, as well as the composition of microcapsules after their synthesis and proved the successful encapsulation and release of the drug. The promising results regarding encapsulation efficiency, Sorafenib release profile and cytotoxicity on HepG2 and mesenchymal stem cells, recommend Sorafenib loaded microcapsules as suitable targeted drug carriers for further in vivo studies for hepatocellular carcinoma therapy.     

Investigation of phantom circuit benefits for next generation xDSL systems

This paper is focused on measurements and analysis of phantom mode benefits in G.fast and next generation xDSL systems. The investigation is based on real measurements performed for a multi‐quad metallic cable together with theoretical evaluations of phantom circuit potentials. Because the presence of phantom circuits leads into increasing the summary crosstalk level in a metallic cable, the application of a phantom mode is questionable in practice. That is why the investigation was performed, and conclusions provided in this paper can be helpful to decide potential benefits of this method for future applications. The elimination of a crosstalk can be performed by using advanced modulation techniques such as vectored discrete multi‐tone modulation (VDMT); however, its application in practice is limited because of its complexity and computational demands. That is why several scenarios are currently being discussed with either no VDMT application or with only partial crosstalk compensation. Because of that, this paper is focused on comparing the results for a first scenario without using any far‐end crosstalk (FEXT) elimination technique, whereas a second scenario is based on partial FEXT suppression by VDMT application, to decide the effectiveness of using phantom modes in practice. Copyright © 2014 John Wiley & Sons, Ltd.     

Determinants of the emergence of modern scientific knowledge in mineralogy (Mexico, 1975–1849): a geohistoriometric approach

Scientometrics - There is increasing interest in rethinking the history of science according to the geographical locations in which production of scientific knowledge occurs. This movement is...     

Model of megalopolises in the tool path optimisation for CNC plate cutting machines

We consider the issues of tool path optimisation under constraints and formulate a mathematical problem of visiting megalopolises. The megalopolises model is the result of the discretisation of the tool path problem for CNC plate cutting machines. The order of visits is subject to precedence constraints. In addition, the cost functions depend on the set of pending tasks. The quality criterion is a variety of the additive criterion. The problem is established within the dynamic programming framework, however, a heuristic is proposed and implemented to solve practical problems of large dimensionality.     

Comparative study of Yb:Lu3Al5O12 and Yb:Lu2O3 laser ceramics produced from laser-ablated nanopowders

We present a comparative study of two Lu-based oxide ceramics doped with Yb³⁺ ions, namely Yb:Lu₃Al₅O₁₂ (garnet) and Yb:Lu₂O₃ (sesquioxide), promising for thin-disk lasers. The ceramics are fabricated using nanopowders of 3.6 at.% Yb:Lu₂O₃ and Al₂O₃ produced by laser ablation: Yb:Lu₃Al₅O₁₂ – by vacuum sintering at 1800 °C for 5 h with the addition of 1 wt% TEOS as a sintering aid, and Yb:Lu₂O₃ – by vacuum pre-sintering at 1250 °C for 2 h followed by Hot Isostatic Pressing at 1400 °C for 2 h under Ar gas pressure of 207 MPa. The comparison includes the structure, Raman spectra, transmission, optical spectroscopy and laser operation. The crystal-field splitting of Yb³⁺ multiplets is revealed for Lu₃Al₅O₁₂. A continuous-wave (CW) Yb:Lu₃Al₅O₁₂ ceramic microchip laser generates 5.65 W at 1031.1 nm with a slope efficiency of 67.2%. In the quasi-CW regime, the peak power is scaled up to 8.83 W. The power scaling for the Yb:Lu₂O₃ ceramic laser is limited by losses originating from residual coloration and inferior thermal behavior.     

Algorithms and implementation of a set partitioning approach for modular machining line design

A transfer line design problem is considered. Transfer lines are sequences of workstations equipped with processing modules called blocks each of which performs specific operations. These lines are used for mass production of one type of product and thus execute repetitively a given set of operations. The machine parts move along the stations in the same direction. An identical cost is associated with each station and differing costs are associated with the blocks. The problem is to determine the number of stations, select a set of blocks and assign selected blocks to the stations so that operations of the selected blocks constitute the original set of operations and the total cost is minimized. A distinct feature of the problem is that operations at the same station are performed in parallel. Plus, there are inclusion, exclusion and precedence relations that restrict the assignment of the blocks and operations to the same station as well as the processing order of the operations on the transfer line. We implement a novel set partitioning formulation of this design problem with pre-processing procedures and heuristics. The presented approach has the best performance among the existing methods in terms of solution time and quality.     

Carbon nanowalls decorated with silicon for lithium-ion batteries

Carbon nanowalls (CNWs) are suggested as a promising nanostructured substrate for 3D anodes of lithium-ion batteries. Silicon sputtering onto CNWs results in improved electrochemical performance due to either a large surface area of free-standing CNWs or easy adhesion of deposited silicon clusters via the SiC interface layer formation. The 3D silicon-decorated nanowall framework (SDNF) could give the possibility to minimize the lithium diffusion length and make charge collection more effective yielding better cycling performance at high rates exceeding 2000 mA h per 1 g of silicon in the range of 0.05–2.00 V at 1.5 C rate.