The influence of attrition milling on carbon dioxide sequestration on magnesium–iron silicate

Present work evaluates the structural changes in olivine (Mg,Fe)₂SiO₄ (deposit Åheim, Norway) generated by mechanical treatment as well as its adsorption properties for carbon dioxide. The high-energy attrition milling was applied for mechanical activation. Identification of the mechanically-induced changes in the mineral was carried out applying various techniques: scanning electron microscopy, Mössbauer spectroscopy, specific surface measurements, carbon dioxide adsorption and Fourier-transformed infrared spectroscopy. The observed changes in the physico-chemical properties illustrate the possibility of the applied activation to modify the surface and/or bulk properties of olivine. Sensitivity for atmospheric CO₂ sequestration as well as sequestration of CO₂ by chemisorption can be derived from the obtained results.     

Mechanochemically activated synthesis of nanostructured NiFe<Subscript>2</Subscript>O<Subscript>4</Subscript>

Powdery NiFe₂O₄ has been obtained by mechanothermal treatment. Nickel and iron hydroxides are used as initial compounds. For comparison the initial compounds are calcinated without mechanical treatment (samples obtained by direct heating). The characterization of the samples is carried out by XRD analysis and Mössbauer spectroscopy. It is established that single phase NiFe₂O₄ is formed after mechanical activation (5 h) and calcination at 773 K. The ferrite synthesized at this temperature contains a smaller quantity of Fe³⁺ ions in tetrahedral position (31%) than is the case of conventional nickel ferrite (50%). The number of tetrahedrally coordinated iron ions increases with enhancement of the synthesis temperature, approaching the distribution of the tetrahedral and octahedral positions typical of conventional NiFe₂O₄. The samples obtained by direct heating contain unreacted NiO and α-Fe₂O₃ even after calcinations at 1073 K.     

Influence of artificial mediators on yeast-based fuel cell performance

Soluble artificial mediators are often applied to enhance the electron transfer from living cells to an anode in microbial fuel cells. Recently, we have demonstrated that the Candida melibiosica 2491 yeast strain possesses electrogenic properties and can be used as a biocatalyst in yeast-based fuel cells even in the absence of artificial mediators. To enhance the generated electrical power, the potential application of several organic compounds as mediators in a C. melibiosica-based fuel cell was examined in this study. The choice of compounds was based upon observed cyclic voltammetry reversible electrochemical behavior at potentials appropriate for mediated electron transfer. Among the studied mediators, methylene blue, methyl orange, methyl red and neutral red significantly increased the current and power outputs in comparison with those obtained with a mediatorless yeast-based fuel cell.     

The views and attitudes of the Clinic of Emergency Surgery of the Clinical Emergency Medical Center at the Queen Ioanna State University Hospital on the potentials of surgical endoscopy in upper digestive hemorrhages

Transendoscopic sclerotherapy of esophageal varix in children and adults is introduced in the clinic of emergency surgery ever since 1973. In children aged 3 to 14 years presenting preportal block a 100 per cent survivorship is recorded 20 years after the manipulation. The outcome of endoscopy in adult patients is successful in 57.69 per cent. Perilesional sclerosing is introduced in the CES in 1982, with a complete and definitive hemostasis attained in 46.7 per cent of the cases. In 1983, transendoscopic electrocoagulation is practically implemented in the CES, with the rate of successfully cured amounting to 55.49 per cent. Having in mind the limitations and contraindications of therapeutic transendoscopic hemostasis in massive hemorrhages, particularly those of ulcerative origin, preference is given to the safer hemostasis by surgical means.     

Corrosion of aluminium and aluminium alloy in ethylene glycol–water mixtures

Samples of pure aluminium and aluminium alloy were heated at 150 kPa and 130 °C in ethylene glycol (EG)–water mixture (volume ratio 1:1) for 172 h (8–12 h heating, 12–16 h pause). The corrosion of the metals was characterised by the transfer of Al into solution, changes in the surface morphology of the samples and their electrochemical behaviour. Formation of a white crystalline aluminium-organic precipitate was found during the heating of metals and some of its characteristics were determined. The effect of the addition of glycolic, citric and sebacic acid to the EG–water mixture on the metal corrosion behaviour was investigated. A significant corrosive action of glycolic acid and a protective effect of sebacic acid were found.     

Cholesteric Liquid Crystals with a Broad Light Reflection Band

The cholesteric‐liquid‐crystalline structure, which concerns the organization of chromatin, collagen, chitin, or cellulose, is omnipresent in living matter. In technology, it is found in temperature and pressure sensors, supertwisted nematic liquid crystal displays, optical filters, reflective devices, or cosmetics. A cholesteric liquid crystal reflects light because of its helical structure. The reflection is selective – the bandwidth is limited to a few tens of nanometers and the reflectance is equal to at most 50% for unpolarized incident light, which is a consequence of the polarization‐selectivity rule. These limits must be exceeded for innovative applications like polarizer‐free reflective displays, broadband polarizers, optical data storage media, polarization‐independent devices, stealth technologies, or smart switchable reflective windows to control solar light and heat. Novel cholesteric‐liquid‐crystalline architectures with the related fabrication procedures must therefore be developed. This article reviews solutions found in living matter and laboratories to broaden the bandwidth around a central reflection wavelength, do without the polarization‐selectivity rule and go beyond the reflectance limit.     

Synthesis of amphiphilic [PEO(PCL)<Subscript>2</Subscript>] triarm star-shaped block copolymers: a promising system for <Emphasis Type="Italic">in cell</Emphasis> delivery

The paper reports on a simple method of synthesizing [PEO(PCL)₂] triarm star-shaped copolymers by a combination of Michael-addition type reaction and ring-opening polymerization. A Michael-addition reaction yielded a PEO end-capped by two hydroxyl groups—a [PEO(OH)₂] macroinitiator—which was used for sequential building of PCL blocks. The macroinitiator and copolymers were analyzed by FTIR, ¹H NMR spectroscopy and SEC. The self-assembly behavior of the copolymers in aqueous media was studied by UV–Vis spectroscopy. The size and morphology of the obtained micelles were determined by TEM. None of the polymers had cytotoxic effects in vitro. Cellular uptake studies showed the accumulation of neutral red loaded micelles in the perinuclear area of human hepatocellular carcinoma cells revealing a cellular uptake associated with macropinocytosis and caveolae mediated endocytosis. The accumulation had a sustained effect over 3 days pointing at the potential application of the copolymers micelles as a drug delivery system.     

Top++: A program for the calculation of the top-pair cross-section at hadron colliders

We present the program Top++ for the numerical evaluation of the total inclusive cross-section for producing top quark pairs at hadron colliders. The program calculates the cross-section in (a) fixed order approach with exact next-to-next-to leading order (NNLO) accuracy and (b) by including soft-gluon resummation for the hadronic cross-section in Mellin space with full next-to-next-to-leading logarithmic (NNLL) accuracy. The program offers the user significant flexibility through the large number (29) of available options. Top++ is written in C++. It has a very simple to use interface that is intuitive and directly reflects the physics. The running of the program requires no programming experience from the user.