The Performance of Small‐Pore Microporous Aluminophosphates in Low‐Temperature Solar Energy Storage: The Structure–Property Relationship

The utilization of the reversible chemical and physical sorption of water on solids provides a new thermal energy storage concept with a great potential for lossless long‐term storage. The performance of microporous aluminophosphates in heat storage applications is highlighted by a comparative thermogravimetric and calorimetric study of three known materials (SAPO‐34, AlPO₄‐18, APO‐Tric) and is correlated with their structural features. The maximum water sorption capacity is similar for all three samples and results in a stored energy density of 240 kWh m^?3 in the 40–140 °C range. The elemental composition influences the gradual (silicoaluminophosphate SAPO‐34) or sudden (aluminophosphates AlPO₄‐18, APO‐Tric) water uptake, with the latter being favourable in storage systems. The driving force for the determined sorption process is the formation of highly ordered water clusters in the pores, which is enabled by rapid and reversible changes in the Al coordination and optimal pore diameters. The ease with which changes in the Al coordination can occur in APO‐Tric is related to the use of the fluoride route in the synthesis. The understanding of these fundamental structure/sorption relationships forms an excellent basis for predicting the storage potential of numerous known or new microporous aluminophosphates and other porous materials from their crystal structures.     

Free amino acid profile during ripening of ewe's milk cheese from the Croatian island Krk

The aim of this study was to determine the content of free amino acids (FAA) and their ratio in ewe's milk cheese from the island Krk during its ripening. FAA content was determined by reversed phase HPLC (RP‐HPLC) of cheese aqueous/ethanol extracts after FAA were transformed into their 6‐aminoquinolyl‐N‐hydroxysuccinimidyl carbamate derivatives. Their concentration increased during ripening, reaching the value of 5% in cheese dry matter. The dominant FAA were glutamic acid>leucine>valine>aspartic acid>phenylalanine>serine>proline, and higher content of nonessential vs essential FAA was revealed. Krk cheese has, in relation to other cheeses, higher values for glutamic acid/leucine, glutamic acid/phenylalanine, glutamic acid/proline and smaller values for leucine/aspartic acid, valine/aspartic acid, phenylalanine/aspartic acid ratios, while other ratios are comparable to those of other hard ovine cheeses.     

Relevance for food sciences of quantitative spatially resolved element profile investigations in wheat (Triticum aestivum) grain

Bulk element concentrations of whole grain and element spatial distributions at the tissue level were investigated in wheat (Triticum aestivum) grain grown in Zn-enriched soil. Inductively coupled plasma mass spectrometry and inductively coupled plasma optical emission spectrometry were used for bulk analysis, whereas micro-proton-induced X-ray emission was used to resolve the two-dimensional localization of the elements. Soil Zn application did not significantly affect the grain yield, but did significantly increase the grain Ca, Fe and Zn concentrations, and decrease the grain Na, P and Mo concentrations; bulk Mg, S, K, Mn, Cu, Cd and Pb concentrations remained unchanged. These changes observed in bulk element concentrations are the reflection of tissue-specific variations within the grain, revealing that Zn application to soil can lead to considerable alterations in the element distributions within the grain, which might ultimately influence the quality of the milling fractions. Spatially resolved investigations into the partitioning of the element concentrations identified the tissues with the highest element concentrations, which is of utmost importance for accurate prediction of element losses during the grain milling and polishing processes.     

Water‐blown polyurethane/polyisocyanurate foams made from recycled polyethylene terephthalate and liquefied wood‐based polyester polyol

Depolymerized polyethylene terephthalate and liquefied wood polyesters can be used as a polyol for the production of polyurethane/polyisocyanurate foams. In this research, liquefied wood was synthesized by using a combination of diethylene glycol and glycerol and due to the possibility of using glycerol that is a by‐product in biodiesel production, our goal was to use as much glycerol in the liquefaction reagent as possible. We determined the properties of the polyols, properties of produced foams, and explained their correlation. Greater amount of glycerol in the liquefaction reagent resulted in higher OH number, molecular weight, functionality, and viscosity of the polyol, as well as in longer cream time and tack free time in foam preparation. Glass transition temperature, density, and water absorption of the foam increased with increasing amount of glycerol in liquefied wood. Compressive stress increased up to 30% of the glycerol in the reagent and then reduced, while thermal conductivity was not affected. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41522.     

Influence of ionic strength and HPMC viscosity grade on drug release and swelling behavior of HPMC matrix tablets

Matrix tablets containing paracetamol and hydroxypropyl methylcellulose (HPMC 2906) of different viscosity grades (50, 400, 1500, and 4000 mPa·s) were evaluated for drug release and change in matrix tablet mass [ΔM (%)] after exposure to 0.09, 0.15, 0.31, and 0.52M ionic strengths of dissolution media. At 0.09 and 0.15M ionic strength, drug‐release profiles reflected the extended release characteristic; in addition the increase in ΔM was slow and continuous within first few hours. At 0.31M the higher viscosity grade matrices showed extensive initial swelling and the loss of extended release whereas at 0.52M a similar tablet performance is observed for the matrices of all viscosity grades. Notably, when extensive increase in ΔM occurs in the very beginning of exposure to medium the loss of extended release from the matrix is expected. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43604.     

Synthesis and Characterization of Rutile TiO2 Nanopowders Doped with Iron Ions

Titanium dioxide nanopowders doped with different amounts of Fe ions were prepared by coprecipitation method. Obtained materials were characterized by structural (XRD), morphological (TEM and SEM), optical (UV/vis reflection and photoluminescence, and Raman), and analytical techniques (XPS and ICP-OES). XRD analysis revealed rutile crystalline phase for doped and undoped titanium dioxide obtained in the same manner. Diameter of the particles was 5–7 nm. The presence of iron ions was confirmed by XPS and ICP-OES. Doping process moved absorption threshold of TiO₂ into visible spectrum range. Photocatalytic activity was also checked. Doped nanopowders showed normal and up-converted photoluminescence.     

Hyperpolarized 129Xe NMR and N2 sorption cross-investigations of the crystallization of Al-SBA-15 amorphous walls into ZSM-5 type materials

The present work deals with the study of the parameters which govern the partial conversion of the amorphous walls of Al-SBA-15 supports into ZSM-5 type deposits under alkaline aqueous conditions. The influence of the mode of insertion of aluminium into Al-SBA-15 as well as of the quantities of ammonium fluoride and ZSM-5 template (TPABr) has been investigated. XRD and nitrogen sorption data indicate that the mesopore network is very fragile under the conditions required for the crystallization of ZSM-5. A compromise was found by using a TPABr/Al molar ratio lower than 1, thus affording materials containing both mesopores and zeolite-type micropores. The combined use of hyperpolarized (HP) ¹²⁹Xe NMR and α-plot studies gave evidence for the ZSM-5 nature of the micropores as well as some indications in favour of the interconnection of the different pore networks. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

The utilisation of grapeseed oil in improving the quality of dry fermented sausages

This study aims to examine the scope of changes in colour, texture and sensory characteristics of fermented sausages by substituting 20% of backfat with grapeseed oil prepared as liquid (GS), encapsulated (EGS) and pre‐emulsified [with soy protein isolate (GSI) and alginate (GSA)], and their stability during 30 days of refrigerated storage. Protein and fat contents, pH and TBA values were not significantly different between products after production and storage. Treatments with added oil had higher weight loss (1.5–2.5%), while moisture content was significantly lowest in GS. Internal product colour evaluation showed the highest values of L*, b* and hue angle in GSI. GSI had the highest hardness and chewiness. Storage affected more surface than internal product colour, hardness was significantly changed only in GSI (lower) and EGS (higher), and increasing of TBA did not lead to significant differences between treatments. The study showed that GSA was the most promising of all treatments investigated.     

Dynamics of capillary water absorption in natural stone

Two natural carbonate stones from Croatia (Kirmenjak avorio and Veselje unito) were analyzed to assess their properties for use in masonry buildings. The results indicated considerable differences in the water absorption (expressed in g/m²) shown as a function of elapsed time. The petrographic analyses highlighted different characteristics as important for the absorption of water in natural stone, including composition, structure, texture and pore system. The importance of assessing the movement of water in the stone relative to its bedding and the construction in which it will be placed is emphasized.