Kinetics of the β-picoline oxidation to nicotinic acid over vanadia-titania catalyst. 2. Effect of dioxygen and β-picoline

The effect of the dioxygen and β-picoline concentrations on the oxidation of β-picoline to nicotinic acid was studied at 270°C over a 20% V₂O₅-80% TiO₂ (wt. %) catalyst. The study was performed in a differential reactor at constant concentrations of water and nicotinic acid. A considerable excess of dioxygen was shown to be necessary for the formation of nicotinic acid. It was found that the rates of β-picoline transformation into nicotinic acid, pyridine-3-carbaldehyde, pyridine-3-nitrile, pyridine and carbon oxides as well as selectivities to products and the catalyst state depend strongly on the ratio of dioxygen to β-picoline concentrations. The minimum admissible ratio of these concentrations under industrial conditions was determined.     

Tetranitromethane as an efficient reagent for the conversion of epoxides into β-hydroxy nitrates

A convenient regioselective method for the preparation of β-hydroxy nitrates based on the ring opening reaction of epoxides by tetranitromethane in the presence of triethylamine is described. A series of substituted β-hydroxy nitrates were obtained in high yields under mild conditions.     

Radioactive caesium (134Cs and 137Cs) in mushrooms of the genus Boletus from the Reggio Emilia in Italy and Pomerania in Poland

Activity concentrations of ¹³⁴Cs and ¹³⁷Cs were determined in mushrooms of the Boletus species B. aereus, B. reticulatus, B. appendiculatus, B. calopus, B. edulis, B. erythropus, B. fechtneri, B. pinophilus, B. pseudoregius, B. rhodopurpureus, B. rhodoxanthus collected in the Reggio Emilia, Italy, in 1993 and 1994 and in B. edulis collected in Pomerania in northern Poland in the period from 1995–2015. Boletus edulis from the Reggio Emilia showed presence of ¹³⁷Cs at 330?±?220?Bq?kg^?1 dry biomass in 1993 and at 370?±?180?Bq?kg^?1 dry biomass in 1994. In B. edulis sampled in the Reggio Emilia in 1993 and 1994, the pre-Chernobyl ¹³⁷Cs from global fallout amounted to 39–46?% of the total activity concentrations of isotope ¹³⁷Cs. B. edulis from Pomerania contained ¹³⁷Cs in caps at 270?±?15?Bq?kg^?1 dry biomass in 1995, and in whole fruiting bodies it was found to be 470?±?9?Bq?kg^?1 dry biomass in 2015. The activity concentrations of ¹³⁷Cs determined in fruiting bodies of B. edulis from Pomerania fluctuated but persisted over the period from 1995 to 2015, while the maximum activity concentrations were well below the tolerance limit of 600?Bq?kg^?1 fresh product.     

An Overview on Food Applications of the Instant Controlled Pressure-Drop Technology,an Innovative High Pressure-Short Time Process

Food processing systematically aims at meeting the needs of consumers who are looking for total high quality and perfect food safety. As the various thermal and non-thermal food preservation technologies often affect the natural properties in terms of sensation, flavor, texture, etc., instant controlled pressure drop (DIC) has been conceived as a relevant, innovative process in this field. DIC uses high saturated steam pressure and short duration to provide a new way to expand biological matrices, improve drying, decontaminate, and extract biologically active compounds, among other attributes. Therefore, this review focuses on describing the applications of DIC technology on a wide range of products such as foods and by-products that have been processed both in the laboratory and on an industrial scale. The application of DIC has shown the possibility of a significant leap in quality improvement and cost reduction in the food industry. DIC reduces the drying time of fruits and vegetables, and improves the extraction of essential oils, vegetable oils, and antioxidant components. It also provides strong decontamination, eliminates vegetative microorganisms and spores, and reduces non-nutritional and allergenic components. Over the past 33 years, this technology has continued to expand its food applications and improve its characteristics on an industrial scale. But there are still many food unit operations that can be taken to the next level with DIC.     

Privacy: An Axiomatic Approach

The increasing prevalence of large-scale data collection in modern society represents a potential threat to individual privacy. Addressing this threat, for example through privacy-enhancing technologies (PETs), requires a rigorous definition of what exactly is being protected, that is, of privacy itself. In this work, we formulate an axiomatic definition of privacy based on quantifiable and irreducible information flows. Our definition synthesizes prior work from the domain of social science with a contemporary understanding of PETs such as differential privacy (DP). Our work highlights the fact that the inevitable difficulties of protecting privacy in practice are fundamentally information-theoretic. Moreover, it enables quantitative reasoning about PETs based on what they are protecting, thus fostering objective policy discourse about their societal implementation.     

Improved efficiency of the sputtering technique for pyrite surface and its effect on reduction of electron beam damage

A quick and highly efficient method is described for the preparation of clean and well‐characterised (100) pyrite surfaces on natural crystals based on a sputter/annealing procedure in an ultra‐high vacuum (UHV) chamber. The improvement has been achieved by controlling the ingress of the key contaminants water and oxygen and restricting the annealing temperature to 560 K, which is below the SO₂ dissociation temperature. Low‐energy electron diffraction (LEED) and X‐ray photoelectron spectroscopy (XPS) data were used to study the surface. As well as improving the efficiency of the sputtering technique for this surface, a further major benefit is its high stability against electron beam damage as investigated by a quantitative LEED study. Copyright © 2008 John Wiley & Sons, Ltd.     

Transfer Function and the State Space Model Identification of a Funnel Shaped Piezoelectric Structure for the Controller Design Purposes

For the controller design purposes in order to suppress vibration magnitudes of a funnel shaped piezoelectric shell structure the mathematical model of the structure was identified in the form of the transfer function and the state space representation. The excitation of the structure with different signal types as well as the measurement of the responses were achieved using the piezoelectric actuator and sensor patches attached to the funnel. From the frequency responses obtained as a ratio of the Fast Fourier Transforms between the appropriate sensor and the actuator signals, discrete-time transfer functions were determined by best curve fitting of the model-based frequency response. For the state space model identification the subspace based identification approach was used. Obtained models were used for the optimal LQ controller design. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Immobilized enzymes and cells in poly(N-vinyl caprolactam)-based hydrogels

A one-step mild method for entrapping animal cells and enzymes in macroporous composite poly (N-vinyl caprolactam)-calcium alginate (PVCL-CaAlg) hydrogels is described. Some properties of immobilized enzymes, such as thermal and storage stabilities and stability in water/organic media were investigated. Composite PVCL-CaAlg gels were successfully applied to immobilize a number of proteases, namely, trypsin, α-chymotrypsin, carboxypeptidase B, and thrombin. Thermal stability of the immobilized preparations obtained by entrapment in hydrogel beads allowed us to use them at 65–80†C, while the native enzymes were completely inactivated at 50–55°C. Various applications of enzymes and cells immobilized in beads weredemonstrated. Immobilized trypsin and carboxypeptidase B were applied to prepare human insulin from recombinant proinsulin. The hydrogel beads with entrapped α-chymotrypsin were used in enantioselective hydrolysis of Shiff's base of D,L-phenylalanine ethyl ester (SBPH) in acetonitrile/water medium. Thrombin immobilized in PVCL-based hydrogel films was shown to be a promising compound for wound treatment. To prepare pure preparations of monoclonal antibodies (MAb) several hybridoma cell lines, including hybridoma cell lines producing MAb to interleukin-2, were successfully cultivated in the hydrogel beads.     

Resolving the sign ambiguity in the singular value decomposition

Many modern data analysis methods involve computing a matrix singular value decomposition (SVD) or eigenvalue decomposition (EVD). Principal component analysis is the time‐honored example, but more recent applications include latent semantic indexing (LSI), hypertext induced topic selection (HITS), clustering, classification, etc. Though the SVD and EVD are well established and can be computed via state‐of‐the‐art algorithms, it is not commonly mentioned that there is an intrinsic sign indeterminacy that can significantly impact the conclusions and interpretations drawn from their results. Here we provide a solution to the sign ambiguity problem and show how it leads to more sensible solutions. Copyright © 2008 John Wiley & Sons, Ltd.     

Erratum: Resolving the sign ambiguity in the singular value decomposition

J. Chemometrics 22 (2): 135–140. DOI: 10.1002/cem.1122 It has come to our attention that an error arose during correction of this article. In Figure 3, Step 3 should as appear as follows: