Formation of valine microcrystals through rapid antisolvent precipitation

In this work we have experimentally studied concentration effects on antisolvent precipitation of valine (an amino acid) from aqueous isopropanol solutions. Our experiments showed that the valine precipitation is very sensitive to both the supersaturation and to the water content in the final solution. Results from spectrophotometric measurements and supersaturation analysis showed that the crystal formation kinetics are strongly dependent on both mixing and concentration profiles in the early stages of the process, even though no visible change in the systems occurs immediately upon mixing with the antisolvent or subsequent dilution. Results from small-angle static light scattering measurements showed that the first visible crystals are of micron size and they grow only little over time, while their number increases gradually. Taken together, these experiments point to intermediate phase separation of (possible amorphous) precursors, being either very small nanoparticles or droplets with their refractive index closely matching that of the continuous phase, which subsequently assemble into micron size valine crystals

The modular method: Milkfish pond culture

The modular method of milkfish culture (Chanos chanos) described in the manual is an improvement over the traditional extensive method. The manual is intended for the use of fish farmers and aquaculturists, extensionists, and students of aquaculture not only in the Philippines, but also in other milkfish-producing countries in Southeast Asia and the world. It covers the following: Interesting facts about milkfish -- biological characteristics, artificial breeding of milkfish; Design and operation of modular pond system -- pond preparation, stocking in the nursery or transition ponds, stocking in the rearing ponds, care of stock, pond utilization and production schedule, harvest and post-harvest; and, Economics and costing

Mudcrab, Scylla spp, production in brackishwater ponds

This manual covers the specifics of grow-out operation — site selection, pond specification, pond preparation, source of juveniles, transport and stocking, care of pond and stock, feeds and feeding, harvest, postharvest. Also includes costs-and-benefits analysis and a list of useful references.Mudcrab (Scylla spp) production in brackishwater ponds is now gaining popularity, especially in communities that need to supplement their income. The manual covers the following: Distribution; Grow-out operation in ponds - site selection, pond specification, pond preparation, source of juveniles, transport and stocking of juveniles, care of pond and stock, feeds and feeding, harvest, post-harvest; Production and profits; Cost and analysis. It is hoped that the manual will be of use to fishfarmers and aquaculturists, extensionists, and students of aquaculture not only in the Philippines but also in other mudcrab producing countries in Southeast Asia

Rietveld Quantitative Phase Analysis of Oil Well Cement: in Situ Hydration Study at 150 Bars and 150 °C

Oil and gas well cements are multimineral materials that hydrate under high pressure and temperature. Their overall reactivity at early ages is studied by a number of techniques including through the use of the consistometer. However, for a proper understanding of the performance of these cements in the field, the reactivity of every component, in real‐world conditions, must be analysed. To date, in situ high energy synchrotron powder diffraction studies of hydrating oil well cement pastes have been carried out, but the quality of the data was not appropriated for Rietveld quantitative phase analyses. Therefore, the phase reactivities were followed by the inspection of the evolution of non‐overlapped diffraction peaks. Very recently, we have developed a new cell specially designed to rotate under high pressure and temperature. Here, this spinning capillary cell is used for in situ studies of the hydration of a commercial oil well cement paste at 150 bars and 150 °C. The powder diffraction data were analysed by the Rietveld method to quantitatively determine the reactivities of each component phase. The reaction degree of alite was 90% after 7 hours, and that of belite was 42% at 14 hours. These analyses are accurate, as the in situ measured crystalline portlandite content at the end of the experiment, 12.9 wt%, compares relatively well with the value determined ex situ by thermal analysis, i.e., 14.0 wt%. The crystalline calcium silicates forming at 150 bars and 150 °C are also discussed.This research was funded by Spanish MINECO, grant number BIA2017‐82391‐R which is co‐funded by FEDER. We thank Marc Malfois for his help during the experiment performed at NCD‐SWEET beamline at ALBA synchrotron. We also thank Marcus Paul (Dyckerhoff GmbH) for providing the OWC sample with its characterization and helpful discussions

Can the use of interactive mediation tools influence the identity proximity between the public and the art museum?

The public and the art museum identity on the one hand, and context on the other hand, seem to influence consumer behaviour in the museum field. It’s not about changing the museum content, but about approaching its identity to the public’s identity, in order to allow access to art. In the first part, we present the theoretical and conceptual framework of the research. A second part will propose the implementation of a qualitative methodological approach and the results exploitation that will let us answer to the previous questions

An Empirical Study of Real-World SPARQL Queries

Understanding how users tailor their SPARQL queries is crucial when designing query evaluation engines or fine-tuning RDF stores with performance in mind. In this paper we analyze 3 million real-world SPARQL queries extracted from logs of the DBPedia and SWDF public endpoints. We aim at finding which are the most used language elements both from syntactical and structural perspectives, paying special attention to triple patterns and joins, since they are indeed some of the most expensive SPARQL operations at evaluation phase. We have determined that most of the queries are simple and include few triple patterns and joins, being Subject-Subject, Subject-Object and Object-Object the most common join types. The graph patterns are usually star-shaped and despite triple pattern chains exist, they are generally short.Comment: 1st International Workshop on Usage Analysis and the Web of Data (USEWOD2011) in the 20th International World Wide Web Conference (WWW2011), Hyderabad, India, March 28th, 201

Synchrotron x-ray pair distribution function: A tool to characterize cement gels

Cement matrices contain large amounts of crystalline phases jointly with amorphous and/or nanocrystalline phases. Consequently, their analyses are very challenging. Synchrotron powder diffraction in combination with the pair distribution function (PDF) methodology is very useful to characterize such complex cement pastes. This work is focused on the study of the short and medium range atomic arrangement(s) in the different nanocrystalline gels which are present in the cement pastes through total scattering Pair Distribution Function quantitative phase analyses.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Acknowledgments: We thank CELLS-ALBA (Barcelona, Spain) for providing synchrotron beam time and the financial support by BIA2014-57658-C2-1-R and BIA2014-57658-C2-2-R, which is co-funded by FEDER. We also thank Dr. Monica Dapiaggi for her contribution with the PDF study of Ca(OH)2 monolayer

Water-to-cement ratio influence on low-carbon cements performances

Portland Cement (PC) is the most important active ingredient in most of the construction concrete. However, the PC production is associated with a high carbon dioxide release (around 1 ton of CO2 per ton of PC). One approach to reduce CO2 emissions consists on the reformulation of the clinker with less calcite demanding phases, such as, belite rich clinkers. The drawback of this kind of clinkers is the low reactivity of belite (beta-belite). In order to compensate this problem, belite rich clinkers can be prepared with ye’elimite and ferrite or with alite [known as belite-ye’elimite-ferrite (BYF) and belite-alite-ye’elimite (BAY), respectively]. In addition, it can be improved by using a high reactive belite polymorph, such as alpha-belite. In this work, the hydration and mechanical behaviour of BYF and BAY cements (with beta and/or alpha-belite) with different water-to-cement ratios have been studied. The clinkers were produced using natural raw materials, and were mixed with anhydrite (CaSO4) to prepare the corresponding cements. At early ages, the main hydration products of these cements were ettringite, calcium monosulfoaluminate and amorphous aluminium hydroxide. At later ages, stratlingite, katoite and amorphous C-S-H were found. The compressive strength values of the corresponding mortars were correlated with the mineralogy evolution of the pastes (mainly obtained by XRD and TGA).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. I3-Ramón y Cajal Universidad de Malag

Nesting of the Aplomado Falcon (<i>Falco f. femoralis </i> )in San Luis province

In this paper we describe the activity of a nesting pair of Aplomado Falcons (Falco f.femoralis) during the first days of the nestling period. The nest was found in a Chañar tree (Geoffroea decorticans) at a heíght of 4.5 m in San Luis province. The female remained at the nest 94.14% of the observation time (brooding: 86.90%) and fed thc nestlings with arate of 0.47 items/h. Feeding periods lasted in average 560 sec (Ra: 360-780 scc; n:9). The male was seen on the nest 1.28% of the obscrvation time and brought prcy with a frequency of 0.41 items/h. Information of nest and nestling characteristics, territory, defense, caching behavior and vocalizations is also given. Finally we provide a compilation about nesting ofthc Aplomado Falcon in Argentina

Synchrotron Radiation Pair Distribution Function Analysis of Gels in Cements

The analysis of atomic ordering in a nanocrystalline phase with small particle sizes, below 5 nm, is intrinsically complicated because of the lack of long-range order. Furthermore, the presence of additional crystalline phase(s) may exacerbate the problem, as is the case in cement pastes. Here, we use the synchrotron pair distribution function (PDF) chiefly to characterize the local atomic order of the nanocrystalline phases, gels, in cement pastes. We have used a multi r-range analysis approach, where the ~4–7 nm r-range allows determining the crystalline phase contents; the ~1–2.5 nm r-range is used to characterize the atomic ordering in the nanocrystalline component; and the ~0.2–1.0 nm r-range gives insights about additional amorphous components. Specifically, we have prepared four alite pastes with variable water contents, and the analyses showed that a defective tobermorite, Ca11Si9O28(OH)2 8.5H2O, gave the best fit. Furthermore, the PDF analyses suggest that the calcium silicate hydrate gel is composed of this tobermorite and amorphous calcium hydroxide. Finally, this approach has been used to study alternative cements. The hydration of monocalcium aluminate and ye’elimite pastes yield aluminum hydroxide gels. PDF analyses show that these gels are constituted of nanocrystalline gibbsite, and the particle size can be as small as 2.5 nmThis work has been supported by Spanish MINECO through BIA2014-57658-C2-2-R, which is co-funded by FEDER, BIA2014-57658-C2-1-R and I3 (IEDI-2016-0079) grants. We also thank CELLS-ALBA (Barcelona, Spain) for providing synchrotron beam time at BL04-MSPD beamline. Finally, we thank Prof. Simon Billinge, Long Yang and Monica Dapiaggi for their help with the PDF script and simulations for Ca(OH)2 scattering dat