Insights into the Crystal Structure and Clathration Selectivity of Organic Clathrates Formed with Hydroquinone and (CO2 + CH4) Gas Mixtures

Organic clathrates, particularly those formed by hydroquinone (HQ) and gas mixtures, have been far less studied than other inclusion compounds, such as gas hydrates. In this study, experiments and molecular dynamics simulations were performed on mixed (CO2 + CH4)–HQ clathrates. Single crystals were synthesized using gas mixtures with different compositions, ranging from pure CO2 to pure CH4. The crystal structure, the guest occupancy in the clathrates, and the variation of the crystal lattice parameters according to clathrate composition were obtained by X-ray diffraction measurements. In addition, molecular dynamics simulations were performed on the same systems, with state-of-the-art molecular models and force fields. The experimental results obtained and the molecular dynamics simulation estimations were in good agreement. The clathration selectivity was also calculated on the basis of experimental results, and the composition of the solid phase was correlated with the composition of the gas phase at equilibrium. These new insights into these structures will be useful from both a fundamental and a practical point of view, particularly for further developing innovative gas separation techniques using HQ clathrates

Re-irradiation of silver nanoparticles obtained by laser ablation in water and assessment of their antibacterial effect

The rapid evolution of resistant bacteria is a huge problem in medicine because makes the treatment of infections more and more difficult. The bactericidal properties of noble metal nanoparticles could be a solution. In this work silver nanoparticles were produced by using two nanosecond Nd:YVO4 lasers operating at 1064 and 532 nm respectively to ablate a silver target submerged in pure de-ionized water. Part of the resulting colloidal solution was injected as a fine stream by a compressed air system and re-irradiated one and three times with the same laser to resize and get uniform nanoparticles. The obtained nanoparticles by ablation and re-irradiation consisted of crystalline Ag nanoparticles with a bimodal size distribution. The particle size has been reduced by subsequent laser re-irradiation with both laser sources, reaching a 40% of mean size reduction. Inhibitory effects on the proliferation of Staphylococcus aureus was demonstrated on silver nanoparticles obtained after re-irradiation with the infrared laser.Postprint (author's final draft

Validated stability-indicating spectrofluorimetric methods for the determination of ebastine in pharmaceutical preparations

Two sensitive, selective, economic, and validated spectrofluorimetric methods were developed for the determination of ebastine (EBS) in pharmaceutical preparations depending on reaction with its tertiary amino group. Method I involves condensation of the drug with mixed anhydrides (citric and acetic anhydrides) producing a product with intense fluorescence, which was measured at 496 nm after excitation at 388 nm

THE MEDIATED EFFECT OF FORMAL AND INFORMAL CONTROL ON GOVERNANCE FORMS

ABSTRACT The present paper employs the perspective of Transaction Cost Economics (TCE) to analyze the relevance of formal and informal controls in selecting the governance form. The evidence supports the influence of frequency, information sharing and relation-specific investments as a cause of control mechanisms, and the effect of these factors on the choice of the governance form, but there is no evidence about the combined interaction between these variables. The present work proposes that there is a mediation effect of formal and informal norms on the relationship between the TCE variables (frequency, information asymmetry and relation-specific investments) and the governance form. We applied Structural Equation Modelling to companies in the telecommunications sector in Spain. Our results confirm the opposite effect of formal and informal controls on the selection of governance forms and the mediation effect of these mechanisms of control on the selection of the governance form

Badanie czynników generujących jakość w relacjach z klientami i dostawcami

The analysis of interorganizational relationships continues to attract academic research because of the influence that management of supply chain relationships has in business competitiveness. However, there are almost no studies about this decision in the mineral products industry. The purpose of this study is to investigate customer-supplier relationships in the non-metallic mineral products mining and manufacturing industry in order to determine what relational forms enable achieving better business competitiveness and higher quality relationships. To carry out this research, we propose a cohesive model comprising variables to characterize the transactions, the forms of governance and both economic and relational results. The paper is based on a transactional framework; thus, the adoption of one or another form of governance is addressed through the length of the relationship, the transmission of information and the dependencies between the agents. As for the outcome, the quality of the relationship is highlighted because of its importance in business competitiveness. The relational quality is understood as the stability of the relationship or the importance given by the buyer to maintaining the relationship or relational commitment. The hypotheses generated are contrasted by a structural equation model in a sample of 293 Spanish companies. The results confirm the importance of past relationships and integrated forms to get better results. In this sense, managers should encourage trust and dependencies because they positively affect performance. Trust and dependencies determine the choice of a vertical form of governance, and these factors, along with information, intervene in the quality of business relationships. Thus, it is possible to say that forms of governance do have effects on the interrelations between the characteristics of the transactions and the business performance.Analiza powiązań międzyorganizacyjnych jest atrakcyjna dla badań naukowych ze względu na wpływ, jaki ma zarządzanie relacjami w łańcuchu dostaw na konkurencyjność przedsiębiorstw. Niemniej jednak, w decyzjach dotyczących przemysłu mineralnego nie ma prawie żadnych badań na ten temat. W artykule dokonano badań relacji między klientami a dostawcami w przemyśle górniczym i przetwórczym niemetalicznych surowców mineralnych w celu określenia, jakie formy relacyjne umożliwiają osiągnięcie lepszej konkurencyjności przedsiębiorstw i wyższe relacje jakościowe. W celu przeprowadzenia tych badań autorzy proponują spójny model, zawierający zmienne charakteryzujące transakcje, formy zarządzania oraz wyniki ekonomiczne i relacyjne. Artykuł oparty jest na ramach transakcyjnych; tym samym przyjęcie jednej lub innej formy zarządzania jest realizowane poprzez długość relacji, przekazywanie informacji i zależności między agentami. Jeśli chodzi o wynik to jakość relacji jest zaznaczona ze względu na jego znaczenie w konkurencyjności przedsiębiorstw. Jakość relacyjna jest rozumiana jako stabilność relacji lub znaczenie przekazane przez nabywcę do utrzymania relacji lub relacyjnego zaangażowania. Wygenerowane hipotezy są przeciwstawiane modelowi równości strukturalnych na próbie 293 hiszpańskich firm. Wyniki potwierdzają znaczenie wcześniejszych relacji i zintegrowanych form w celu uzyskania lepszych wyników. W tym znaczeniu, menedżerowie powinni zachęcać do zaufania i zależności, ponieważ wpływa to pozytywnie na wydajność. Zaufanie i zależności decydują o wyborze pionowej formy zarządzania, a te czynniki wraz z informacjami wpływają na jakość relacji biznesowych. Można zatem powiedzieć, że formy zarządzania mają wpływ na wzajemne powiązania między charakterystykami transakcji a wynikami działalności

Las Ciencias y Tecnologías Marinas en España

Páginas: 282, Formato: 24x17En un país como el nuestro, con más de 7.800 km de línea de costa y una historia, cultura y economía íntimamente vinculadas al océano, las ciencias y tecnologías marinas están llamadas a jugar un importante papel. La investigación marina cuenta con una gran tradición en nuestro país y un contingente de investigadores que, desde distintas instituciones, realizan una labor de investigación que destaca, por su calidad, entre las aportaciones científicas españolas.Peer reviewe

Development of bioprocesses for the integral valorisation of fish discards

11 pages, 3 figures, 7 tables.In the present work, we have developed a set of sequential and complementary alternatives to valorise five fish discards in order to recover and produce fish mince, oils, gelatins, fish protein hydrolysates (FPHs) with antioxidant and antihypertensive properties and marine peptones. In this last case, microbial bioconversion of marine peptones was studied by Pediococcus acidilacti growth, a well-known valuable lactic acid bacterium, and the concomitant production of lactic acid and pediocin SA-1. Highly digestible FPHs with a good quality of amino acids composition and antioxidant and antihypertensive properties were easily produced. In the same bioprocess, fish oils with a healthy ω-3/ ω-6 ratio were also isolated. The use of peptones derived from FPHs as bacterial media nutrient (source of organic nitrogen) led to reduction of bioproductions costs between 2–5 folds in comparison with commercial culture medium.This research was funded by the projects iSEAS LIFE13 ENV/ES/000131 (LIFE+Programme, EU) and CVMar+i (0302_CVMAR_I_1_P, POCTEP 2015).Peer reviewe