O adsorption and incipient oxidation of the Mg(0001) surface

First principles density functional calculations are used to study the early oxidation stages of the Mg(0001) surface for oxygen coverages 1/16 <= Theta <= 3 monolayers. It is found that at very low coverages O is incorporated below the topmost Mg layer in tetrahedral sites. At higher oxygen-load the binding in on-surface sites is increased but at one monolayer coverage the on-surface binding is still about 60 meV weaker than for subsurface sites. The subsurface octahedral sites are found to be unfavorable compared to subsurface tetrahedral sites and to on-surface sites. At higher coverages oxygen adsorbs both under the surface and up. Our calculations predict island formation and clustering of incorporated and adsorbed oxygen in agreement with previous calculations. The calculated configurations are compared with the angle-scanned x-ray photoelectron diffraction experiment to determine the geometrical structure of the oxidized Mg(0001) surface.Comment: 10 pages, 5 figure

A qualitative evaluation of the impact of a palliative care course on preregistration nursing students' practice in Cameroon

Background Current evidence suggests that palliative care education can improve preregistration nursing students’ competencies in palliative care. However, it is not known whether these competencies are translated into students’ practice in the care of patients who are approaching the end of life. This paper seeks to contribute to the palliative care evidence base by examining how nursing students in receipt of education report transfer of learning to practice, and what the barriers and facilitators may be, in a resource-poor country. Methods We utilised focus groups and individual critical incident interviews to explore nursing students’ palliative care learning transfer. Three focus groups, consisting of 23 participants and 10 individual critical incident interviews were conducted with preregistration nursing student who had attended a palliative care course in Cameroon and had experience caring for a patient approaching the end of life. Data was analysed thematically, using the framework approach. Results The results suggest that nursing students in receipt of palliative care education can transfer their learning to practice. Students reported recognizing patients with palliative care needs, providing patients with physical, psychosocial and spiritual support and communicating patient information to the wider care team. They did however perceive some barriers to this transfer which were either related to themselves, qualified nurses, the practice setting or family caregivers and patients. Conclusion The findings from this study suggest that nursing student in receipt of palliative care education can use their learning in practice to provide care to patients and their families approaching the end of life. Nevertheless, these findings need to be treated with some caution given the self-reported nature of the data. Demonstrating the link between preregistration palliative care education and patient care is vital to ensuring that newly acquired knowledge and skills are translated and embedded into clinical practice. This study also has implications for advocating for palliative care policies and adequately preparing clinical placement sites for students’ learning and transfer of learning

Study of the properties of thermoset materials derived from epoxidized soybean oil and protein fillers

[EN] Novel bio-based thermoset formulations were prepared by using epoxidized soybean oil (ESBO), nadic methyl anhydride as a hardener and with different types of proteins as fillers. In the first part of the study, the effect of the protein-type (wheat gluten, soy protein, casein and ovalbumin) on cured ESBO materials was investigated. Thermal and mechanical properties were characterized by flexural tests, Shore D hardness, Charpy impact tests, Vicat softening temperature and heat deflection temperature. In addition, a study of the morphology of fractured surfaces by scanning electron microscopy was carried out. In general, the addition of protein-based fillers improved the mechanical and thermal properties. It was found that the highest increase of thermal and mechanical properties was achieved by ovalbumin. In the second part of the work, the effect of the total amount of ovalbumin filler was studied. Bio-based thermoset materials from ESBO and 15 wt % ovalbumin improved flexural modulus more than 150 % when compared to the unfilled material. Similar evolution was observed for other mechanical properties. Moreover, the brittleness of this composition was the minimum from the studied systems. A direct relationship between energy absorption capacity and morphologies of the failure surface was evidenced by SEM.This work is a part of the project IPT-310000-2010-037,"ECOTEXCOMP: Research and development of textile structures useful as reinforcement of composite materials with marked ecological character" funded by the "Ministerio de Ciencia e Innovacion", with an aid of 189540.20 euros, within the "Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica 2008-2011" and funded by the European Union through FEDER funds, Technology Fund 2007-2013, "Operational Programme on R+D+I for and on behalf of the companies". Also, Generalitat Valenciana ACOMP/2012/087 is acknowledged for financial support.Fombuena Borrás, V.; Sánchez Nacher, L.; Samper Madrigal, MD.; Juárez Varón, D.; Balart Gimeno, RA. (2013). Study of the properties of thermoset materials derived from epoxidized soybean oil and protein fillers. Journal of the American Oil Chemists' Society. 90(3):449-457. https://doi.org/10.1007/s11746-012-2171-2S449457903Alonso MV, Oliet M, Garcia J, Rodriguez F, Echeverria J (2006) Gelation and isoconversional kinetic analysis of lignin-phenol-formaldehyde resol resins cure. Chem Eng J 122:159–166Altuna FI, Esposito LH, Ruseckaite RA, Stefani PM (2011) Thermal and mechanical properties of anhydride-cured epoxy resins with different contents of bio-based epoxidized soybean oil. J Appl Polym Sci 120:789–798Boquillon N, Fringant C (2000) Polymer networks derived from curing of epoxidised linseed oil: influence of different catalysts and anhydride hardeners. Polymer 41:8603–8613Boquillon N, Elbez G, Schonfeld U (2004) Properties of wheat straw particleboards bonded with different types of resin. J Wood Sci 50:230–235Chakrapani S, Crivello JV (1998) Synthesis and photoinitiated cationic polymerization of epoxidized castor oil and its derivatives. J Macromol Sci-Pure Appl Chem A35:1–20Chen F, Zhang JW (2009) A new approach for morphology control of poly(butylene adipate-co-terephthalate) and soy protein blends. Polymer 50:3770–3777Cuq B, Contard N, Guilbert S (1998) Proteins as agricultural polymers for packaging production. Am Assoc Cereal Chem 75:1–9Czub P (2006) Application of modified natural oils as reactive diluents for epoxy resins. Macromol Symp 242:60–64DdS Martini, Braga BA, Samios D (2009) On the curing of linseed oil epoxidized methyl esters with different cyclic dicarboxylic anhydrides. Polymer 50:2919–2925Dogan E, Kuesefoglu S (2008) Synthesis and in situ foaming of biodegradable malonic acid ESO polymers. J Appl Polym Sci 110:1129–1135Espinosa-Perez J, Wiesenborn DP, Tostenson K, Ulven CA, Tatlari M (2007) Preparation and partial characterization of canola-based epoxy resins for bio-based plastic composites. ASABE Annual International Meeting, 076079, Minneapolis, MNJin H, Zhang L, Chen F (2003) Effects of lignin as a filler on properties of soy protein plastics. I Lignosulfonate. J Appl Polym Sci 88:3284–3290Liu ZS, Erhan SZ, Calvert PD (2007) Solid freeform fabrication of epoxidized soybean oil/epoxy composite with bis or polyalkyleneamine curing agents. Compos Part A Appl Sci Manuf 38:87–93Matejka L, Lovy J, Pokorny S, Bouchal K, Dusek K (1983) Curing epoxy-resins with anhydrides—model reactions and reaction-mechanism. J Polym Sci Part A Polym Chem 21:2873–2885Miyagawa H, Mohanty AK, Drzal LT, Misra M (2005) Nanocomposites from bio-based epoxy and single-wall carbon nanotubes: synthesis, and mechanical and thermo-physical properties evaluation. Nanotechnology 16:118–124Mohamed A, Finkenstadt VL, Gordon SH, Palmquist DE (2010) Thermal and mechanical properties of compression-molded pMDI-reinforced PCL/gluten composites. J Appl Polym Sci 118:2778–2790Montero de Espinosa L, Ronda JC, Galià M, Cádiz V (2008) A new enone-containing triglyceride derivative as precursor of thermosets from renewable resources. J Polym Sci Part A Polym Chem 46:6843–6850Park SJ, Jin FL, Lee JR (2004) Synthesis and thermal properties of epoxidized vegetable oil. Macromol Rapid Commun 25:724–727Pfister DP, Baker RJ, Henna HP, Lu Y, Larock CR (2008) Preparation and properties of tung oil-based composites using spent germ as a natural filler. J Appl Polym Sci 108:3618–3625Reiznautt QB, Garcia ITS, Samios D (2009) Oligoesters and polyesters produced by the curing of sunflower oil epoxidized biodiesel with cis-cyclohexane dicarboxylic anhydride: synthesis and characterization. Mater Sci Eng C Mater Biol Appl 29:2302–2311Rüsch Gen Klaas M, Warwel S (1999) Complete and partial epoxidation of plant oils by lipase-catalyzed perhydrolysis. Ind Crops Prod 9:125–132Sailaja RRN, Girija BG, Madras G, Balasubramanian N (2008) Effect of compatibilization on mechanical and thermal properties of polypropylene—soy flour composites. J Mater Sci 43:64–67Samper MD, Fombuena V, Boronat T, García-Sanoguera D, Balart R (2012) Thermal and mechanical characterization of epoxy resins (ELO and ESO) cured with anhydrides. J Am Oil Chem Soc 89(8):1521–1528Sharma S (2008) Fabrication and characterization of polymer blends and composites derived from biopolymers. Philosophy Materials Science and Engineering. Graduate School of Clemson University, ClemsonSharma BK, Liu Z, Adhvaryu A, Erhan SZ (2008) One-pot synthesis of chemically modified vegetable oils. J Agric Food Chem 56:3049–3056Sue HJ, Wang S, Jane J (1997) Morphology and mechanical behaviour of engineering soy plastics. J Polym 38:5035Wang S, Sue HJ, Jane J (1996) Effects of polyhydric alcohols on the mechanical properties of soy protein plastics. J Macromol Sci Pure Appl Chem A33:557–569Wazzan AA, Al-Turaif HA, Abdelkader AF (2006) Influence of submicron TiO2 particles on the mechanical properties and fracture characteristics of cured epoxy resin. Polym Plastics Technol Eng 45:1155–116