Stabilization and Consolidation of Historical Multi-Leaf Masonry

Historical masonry structures with a greater thickness can often be made as so called multi-leaf masonry with outer leaves lined with the application of some of the masonry bonding methods and with the inner leave of the so-called cast core formed by fragments of stones of different sizes that are bonded with more mortar. The load capacity, stiffness and the failure mechanism of multi-leaf masonry are influenced by the interaction of individual leaves with different deformation and physico-mechanical properties and the nature of the mutual connection of individual leaves of masonry. The performed analyses showed a significant influence of especially the cast core masonry tensile strength and the contact joint strength between the core masonry and the outer leaves

Differences in Activities of Antioxidant Superoxide Dismutase, Glutathione Peroxidase and Prooxidant Xanthine Oxidoreductase/Xanthine Oxidase in the Normal Corneal Epithelium of Various Mammals

Summary Under normal conditions, antioxidants at the corneal surface are balanced with the production of reactive oxygen species without any toxic effects. Danger from oxidative stress appears when natural antioxidants are overwhelmed leading to antioxidant/prooxidant imbalance. The aim of the present study was to examine the activities of enzymes contributing to the antioxidant/prooxidant balance in normal corneal epithelium of various mammals. The enzyme activities of antioxidant superoxide dismutase and glutathione peroxidase, as well as prooxidant xanthine oxidoreductase/xanthine oxidase were examined using biochemical methods. Results show that superoxide dismutase activity is high in rabbits and guinea pigs, whereas in pigs the activity is low and in cows it is nearly absent. In contrast, glutathione peroxidase activity is high in cows, pigs and rabbits, whereas in guinea pigs the activity is low. As far as prooxidant enzymes are concerned, elevated xanthine oxidoreductase/xanthine oxidase activities were found in rabbits, lower activities in guinea pigs, very low activity in cows and no activity in pigs. In conclusion, the above results demonstrate inter-species variations in activities of enzymes participating in antioxidant/prooxidant balance in the corneal epithelium. It is suggested that the levels of antioxidant and prooxidant enzymes studied in the corneal epithelium might be associated with the diurnal or nocturnal activity of animals. UV rays decompose hydrogen peroxide to damaging hydroxyl radicals and perhaps for this reason large animals with diurnal activity (cow, pig) require more effective peroxide removal (high glutathione peroxidase activity) together with the suppression of peroxide production (low superoxide dismutase activity, low xanthine oxidoreductase activity)

Synthesis and Characterisation of Hierarchically Structured Titanium Silicalite‐1 Zeolites with Large Intracrystalline Macropores

The successful synthesis of hierarchically structured titanium silicalite‐1 (TS‐1) with large intracrystalline macropores by steam‐assisted crystallisation of mesoporous silica particles is reported. The macropore topology was imaged in 3D by using electron tomography and synchrotron radiation‐based ptychographic X‐ray computed tomography, revealing interconnected macropores within the crystals accounting for about 30 % of the particle volume. The study of the macropore formation mechanism revealed that the mesoporous silica particles act as a sacrificial macropore template during the synthesis. Silicon‐to‐titanium ratio of the macroporous TS‐1 samples was successfully tuned from 100 to 44. The hierarchically structured TS‐1 exhibited high activity in the liquid phase epoxidation of 2‐octene with hydrogen peroxide. The hierarchically structured TS‐1 surpassed a conventional nano‐sized TS‐1 sample in terms of alkene conversion and showed comparable selectivity to the epoxide. The flexible synthesis route described here can be used to prepare hierarchical zeolites with improved mass transport properties for other selective oxidation reactions

Greener Method to Obtain a Key Intermediate of Vitamin E over Cu-ZSM-5

The catalytic oxidation of 2,3,5-trimethylphenol was performed over transition metals modified ZSM-5 zeolites employing hydrogen peroxide as oxidant under mild reaction conditions. Catalysts samples were characterized by several techniques (XRD, FTIR, BET, AA) and cristallinity and orthorhombic symmetry were confirmed for all of them. Best catalytic results were obtained for Cu-ZSM-5 sample, so further activity studies were done over this material. 2,3,5-trimethyl-1,4-benzoquinone was obtained as the main product of the selective oxidation. Reaction parameters (nature of the solvent, hydrogen peroxide concentration, reaction time, catalyst mass, substrate initial concentration and reaction temperature) were evaluated to reach the optimum reaction conditions. According to the obtained results, an apparent activation energy of 52.33 kJ/mol was calculated.Fil: Saux, Clara. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Centro de Investigacion y Tecnologia Quimica; Argentina. Universidad Tecnologica Nacional. Facultad Regional Cordoba; ArgentinaFil: Renzini, Maria Soledad. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Centro de Investigacion y Tecnologia Quimica; Argentina. Universidad Tecnologica Nacional. Facultad Regional Cordoba; ArgentinaFil: Gómez, Silvina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Centro de Investigacion y Tecnologia Quimica; Argentina. Universidad Tecnologica Nacional. Facultad Regional Cordoba; ArgentinaFil: Pierella, Liliana Beatriz. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Cordoba. Centro de Investigacion y Tecnologia Quimica; Argentina. Universidad Tecnologica Nacional. Facultad Regional Cordoba; Argentin

Stabilization of Scandium Terephthalate MOFs against Reversible Amorphization and Structural Phase Transition by Guest Uptake at Extreme Pressure

Previous high-pressure experiments have shown that pressure-transmitting fluids composed of small molecules can be forced inside the pores of metal organic framework materials, where they can cause phase transitions and amorphization and can even induce porosity in conventionally nonporous materials. Here we report a combined high-pressure diffraction and computational study of the structural response to methanol uptake at high pressure on a scandium terephthalate MOF (Sc2BDC3, BDC = 1,4-benzenedicarboxylate) and its nitro-functionalized derivative (Sc2(NO2–BDC)3) and compare it to direct compression behavior in a nonpenetrative hydrostatic fluid, Fluorinert-77. In Fluorinert-77, Sc2BDC3 displays amorphization above 0.1 GPa, reversible upon pressure release, whereas Sc2(NO2–BDC)3 undergoes a phase transition (C2/c to Fdd2) to a denser but topologically identical polymorph. In the presence of methanol, the reversible amorphization of Sc2BDC3 and the displacive phase transition of the nitro-form are completely inhibited (at least up to 3 GPa). Upon uptake of methanol on Sc2BDC3, the methanol molecules are found by diffraction to occupy two sites, with preferential relative filling of one site compared to the other: grand canonical Monte Carlo simulations support these experimental observations, and molecular dynamics simulations reveal the likely orientations of the methanol molecules, which are controlled at least in part by H-bonding interactions between guests. As well as revealing the atomistic origin of the stabilization of these MOFs against nonpenetrative hydrostatic fluids at high pressure, this study demonstrates a novel high-pressure approach to study adsorption within a porous framework as a function of increasing guest content, and so to determine the most energetically favorable adsorption sites

Current trend in synthesis, Post-Synthetic modifications and biological applications of Nanometal-Organic frameworks (NMOFs)

Since the early reports of MOFs and their interesting properties, research involving these materials has grown wide in scope and applications. Various synthetic approaches have ensued in view of obtaining materials with optimised properties, the extensive scope of application spanning from energy, gas sorption, catalysis biological applications has meant exponentially evolved over the years. The far‐reaching synthetic and PSM approaches and porosity control possibilities have continued to serve as a motivation for research on these materials. With respect to the biological applications, MOFs have shown promise as good candidates in applications involving drug delivery, BioMOFs, sensing, imaging amongst others. Despite being a while away from successful entry into the market, observed results in sensing, drug delivery, and imaging put these materials on the spot light as candidates poised to usher in a revolution in biology. In this regard, this review article focuses current approaches in synthesis, post functionalization and biological applications of these materials with particular attention on drug delivery, imaging, sensing and BioMOFs

Timing of the Neoglacial onset on the north-eastern Antarctic Peninsula based on lacustrine archive: Dataset from Lake Anónima, Vega Island

Description of this data: Dataset_Lake_Anonima_2013_1.0_(8-11-2018).xlsx Title: Timing of the Neoglacial onset on the north-eastern Antarctic Peninsula based on lacustrine archive: Dataset from Lake Anónima, Vega Island Version: 1.0 Date of Release: 8th November 2018 Identifier: doi:10.17632/kbrxvfmhf6.1 Permalink: http://dx.doi.org/10.17632/kbrxvfmhf6.1 Contact information: Tomáš Čejka, Masaryk University ([email protected]) Dates of data collection: February 2013 Geographic location: Vega Island, Antarctic Peninsula, Antarctica We refer the user to the original manuscript (see above) for additional general information regarding the collection and generation of these data

Ensuring quality control during determination of PBC in beer, using statistic control of surrogate standard.

In the framework of a good laboratory praxis the emphasis is placed to the quality of reproducible results. For this reason are very useful methods of mathematical statistics, which in the form of regulating diagrams, can help to the speed identification of that results, which are outside the required tolerances. There are a lot of various samples used for statistical regulation. One possibility how to control the efficiency of whole analytic process, from prepearing to the final determination, is using of surrogate standard. For PCB determination in various types of water were found as a surrogate standard following two compounds: 2,4,5,6-tetrachlor-m-xylen and decachlorbifenyl. Above mentioned compounds were examined during relativly complicated of PCB in beer. The concentration was determined by Shewhart's diagrams for individual values and sliding span according to standard ČSN ISO 8258. This example of PCB determination in beer indicates the possibility to use surrogate standards as a powerful instrument for determination of results quality.In the framework of a good laboratory praxis the emphasis is placed to the quality of reproducible results. For this reason are very useful methods of mathematical statistics, which in the form of regulating diagrams, can help to the speed identification of that results, which are outside the required tolerances. There are a lot of various samples used for statistical regulation. One possibility how to control the efficiency of whole analytic process, from prepearing to the final determination, is using of surrogate standard. For PCB determination in various types of water were found as a surrogate standard following two compounds: 2,4,5,6-tetrachlor-m-xylen and decachlorbifenyl. Above mentioned compounds were examined during relativly complicated of PCB in beer. The concentration was determined by Shewhart's diagrams for individual values and sliding span according to standard ČSN ISO 8258. This example of PCB determination in beer indicates the possibility to use surrogate standards as a powerful instrument for determination of results quality

Satatystyczna analiza jakości kontroli i zanieczyszczeń piwa za pomocą standardów zastępczych

In the framework of good laboratory praxis the emphasis is placed on the quality of reproducible results. Methods of mathematic statistics are very useful for this reason. In the form of regulating diagrams they can help to quick identification of that results which are outside the required tolerances. There are a lot of various samples used for statistical regulation. One possibility how to control the efficiency of whole analytic process, from preparing to the final determination, is using of surrogate standard. 2,4,5,6-tetrachloro-m-xylene and decachlorobiphenyl were used as surrogate standards for the determination of PCB in various types of water. These compounds were examined during relatively complicate determination of PCB in beer. The concentration was determined by Shewhart’s diagrams for individual values and sliding span according to standard ČSN ISO 8258. This example of PCB determination in beer indicates the possibility of using surrogate standards as a powerful tool for determination of quality results.W ramach dobrej praktyki laboratoryjnej kładzie się nacisk na jakość uzyskanych wyników. Do ich oceny wykorzystuje się matematyczne metody statystyczne. Za pomocą schematycznych diagramów można szybko zidentyfikować wyniki pozostające poza wymaganymi granicami tolerancji. Istnieje wiele różnych metod statystycznych używanych do tych celów. Jedną z możliwości kontroli efektywności całego procesu analitycznego, od przygotowania próbki do końcowego oznaczenia, jest użycie standardów zastępczych. Do oznaczania PCB w różnych rodzajach wody użyto 2,4,5,6-tetrachloro-m-ksylenu i dekachlorobifenylu jako wzorców zastępczych. Związki te zostały zbadane podczas stosunkowo skomplikowanego oznaczania PCB w piwie. Stężenie zostało określone za pomocą schematów Shewharta dla poszczególnych wartości, zgodnie z normą ČSN ISO 8258. Ten przykład oznaczania PCB w piwie wskazuje na możliwość korzystania ze standardów zastępczych jako istotnego narzędzia do określenia jakości wyników

Application of Gel-Permeation Chromatography for Determination of Organic Pollutants in Brewing Barley.

A  method   was  developed  that   enables,  within  one extraction  step,  to  determine  nine  polycyclic  aromatic hydrocarbons    (PAH)   -    benzo(a)anthracene,   chrysene, benzo(b)fluoranthene,  benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene,    indeno(1,2,3-cd)pyrene,dibenzo(a, i)pyrene,   dibenzo(a,h)pyrene   -   and   seven  indicating congeners of polychlorinated biphenyls  (PCB) - congeners of No. 28, 52, 101, 118, 138, 153, 180 - in vegetable matrixes, mainly in  barley and malt.  The assay process  includes the description of  extraction and purification  of the acquired extract by means of the gel-permeation chromatography method with   the  use   of  gel   on  the   basis  of  polymer  of styrenedivinylbenzene   (Bio-Beads  SX-3).In   this  way  an extract   is   obtained   of   sufficient   purity  for  the determination of  both PAH and  PCB. The final  assay of PAH was  carried  out  by  the  method  of high-efficient liquid chromatography and  the assay of  PCB by gas  chromatography using the electron capture detector. All analytes can be set in microgram amounts with a relative authoritative deviation < 25 %.     The study contains characteristics of the method for all stipulated substances and speciment chromatograms.A  method   was  developed  that   enables,  within  one extraction  step,  to  determine  nine  polycyclic  aromatic hydrocarbons    (PAH)   -    benzo(a)anthracene,   chrysene, benzo(b)fluoranthene,  benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene,    indeno(1,2,3-cd)pyrene,dibenzo(a, i)pyrene,   dibenzo(a,h)pyrene   -   and   seven  indicating congeners of polychlorinated biphenyls  (PCB) - congeners of No. 28, 52, 101, 118, 138, 153, 180 - in vegetable matrixes, mainly in  barley and malt.  The assay process  includes the description of  extraction and purification  of the acquired extract by means of the gel-permeation chromatography method with   the  use   of  gel   on  the   basis  of  polymer  of styrenedivinylbenzene   (Bio-Beads  SX-3).In   this  way  an extract   is   obtained   of   sufficient   purity  for  the determination of  both PAH and  PCB. The final  assay of PAH was  carried  out  by  the  method  of high-efficient liquid chromatography and  the assay of  PCB by gas  chromatography using the electron capture detector. All analytes can be set in microgram amounts with a relative authoritative devia