A robust method for axis identification

The present paper proposes a new method for axis identification in discrete axially symmetrical geometric models. This method is based on-a-never-used-before property of the axially symmetrical surfaces for which the symmetry line of any section curve of the surface (or of a portion of it in the case of an incomplete axially symmetrical surface) always intersects the axis of symmetry of the surface. Thus the working principle of the method makes it very robust to local defectiveness, measurement noise and outliers.In order to compare it with the most cited methods presented in literature, several types of tests have been designed and performed. The robustness of those methods, on the one hand, has been evaluated by defining the Statistical Confidence Boundary at 1σ confidence level. The trueness of the method, on the other hand, has been evaluated on geometric models obtained by measuring real objects. The high robustness, which characterizes the proposed method, makes it particularly suitable for product geometric inspection where high accuracy is required.     

Efficient hydrogen production for industry and electricity storage via high-temperature electrolysis

The paper describes the development status of Sunfire's reversible solid oxide cell (RSOC) technology. Here, Sunfire is a pioneer in the field of high-temperature electrolysers (HTE) for renewable hydrogen production which can be operated as a fuel cell for power generation in a reverse mode. The maturity of the technology is improved stepwise so that first applications in the field of hydrogen production for industry and electricity storage can be tackled. Three application examples where larger scale prototype has been installed will be discussed: 1) A power-to-power electricity storage based on hydrogen, 2) a RSOC unit that is installed in an iron and steel works, and 3) a pressurized SOEC prototype which will be integrated with a methanation unit. Results show the potentials of the technology in connection with fluctuating renewable energy sources.     

Quaternary nitrogen activated carbons for removal of perchlorate with electrochemical regeneration

Positively charged nitrogen functional groups were introduced onto the surface of granular activated carbon (GAC), and these increased perchlorate anion removal from drinking water sources. Nitrogen functionalization involved three treatment steps: (1) introducing oxygen groups onto the GAC, (2) incorporating nitrogen groups by thermal treatment in ammonia flow to replace O with N, and (3) quaternerizing pyridine-like groups to create positively charged pyridinium-like groups. Functionalized bituminous GAC provided 6 times more perchlorate removal than its predecessor, pristine bituminous GAC. The conversion of pyridine-like groups (after step 2) to pyridinium-like groups by quaternization (step 3) was confirmed by analysis of the XPS N 1s signals and surface charge analysis. Redox peaks, observed during cyclic voltammetry analysis of the functionalized GAC, evidenced that these nitrogen functional groups were electrochemically active, so that they sorbed perchlorate when they were oxidized, and then desorbed perchlorate when reduced. Moreover, after sorbing perchlorate onto pyridinium-GAC in RSSCTs, the GAC media could be regenerated by electrochemical reduction, and its capacity for perchlorate adsorption was mostly restored. This tailored functionality and redox regeneration of a relatively inexpensive media such as activated carbon could offer novel opportunity to the adsorption industry.     

Reduction of excessive energy in the four-noded membrane quadrilateral element. Part I: Linear theory-compressible materials

The objective of the paper is to set forth, in a consistent manner, reasons for the appearance of excessive energy in the four-noded membrane quadrilateral element and to propose a formulation leading to simple and reliable elements that are less sensitive to distortions of the geometrical shape. By presenting the differential geometry, emphasis is placed upon those geometrical attributes which are inherently related to the quadrilateral. A modified version of the functional of Hu-Washizu is employed for the discretization. Appropriate approximations for the displacements/rotations are chosen and the physical meaning of the various parameters is identified. A systematic procedure is followed for the approximation of stress and strain. The convergence of the formulation is investigated by examining the inf–sup condition and applying the patch test. Also, results of numerical examples and comparisons with other elemental formulations are presented.     

Simultaneous determination of cholesterol oxides,cholesterol and fatty acids in processed turkey meat products

Cholesterol oxides, cholesterol, total lipids and fatty acids were determined in the lipid extracts from eight processed turkey meat products (blanquet, frankfurter, ham, meatball, smoked breast, smoked ham and roule). Cholesterol and cholesterol oxides were determined simultaneously by high performance liquid chromatography using a diode array detector at 210 nm and a refractive index detector. Only two cholesterol oxides were identified, 7-ketocholesterol (not detected up to 184 μg/100 g) and β-epoxycholesterol (not detected up to 450 μg/100 g). With the exception of the meatballs, hamburger and frankfurters, all the turkey meat products showed less than 5% fat, and could thus be considered as low fat foods. The cholesterol content varied from 32 to 43 mg/100 g, the ratio of polyunsaturated:saturated fatty acids varied from 1.1 to 1.8 and the ratio of ω6:ω3 from 18 to 28. Trans fatty acids were present in significant amounts in both hamburger and meatball.     

Synthesis and light emitting properties of fluorene–carbazole-based conjugated copolymers

A novel series of soluble conjugated copolymers comprised of 9,9′-bis(2-ethylhexylfluorene) and comonomer included carbazole moiety, 3,6-bis[1-{4-bromobenz(1-cyanovinylene)}]-9-(2-ethylhexyl)-carbazole (BCEC), were synthesized by nickel-catalyzed Yamamoto coupling reaction. The resulting copolymers exhibit good solubility in common organic solvents such as chloroform, chlorobenzene, etc. and good thermal stability. The copolymers are also easily cast in thin film on glass substrate. By means of the feed ratio, the electronic and optical properties of the polymers were tuned. The UV-Vis spectra of polymers exhibit absorption band at about 382 nm. These polymers showed photoluminescence (PL) maxima at 466 and 479 nm, respectively. The electroluminescence (EL) spectrum results were similar to the PL spectra. However, the EL spectra showed the possibility of the white light emission through the electroplex emission around 700 nm from the single polymer device. The EL spectra of the devices were little changed with the various current densities.