Estudio del comportamiento de diversos residuos de catalizadores de craqueo catalítico (FCC) en cemento Portland

The fluidized-bed catalytic cracking catalyst (FCC) it is a residue from the industry of the petroleum that shows a high pozzolanic reactivity and, in cementing matrix, it significantly improves their mechanical behaviour as well as durability. In this research a comparative study on residues of catalyst from different sources has been carried out, in order to know if these residues can be used jointly in an indiscriminate way or, on the contrary, it is necessary to classify them according to their characteristics. Thus, a study on five different FCC residues, supplied from different companies, has been carried out, and their physical-chemical characteristics, pozzolanic reactivity by means of thermogravimetric analysis and the evolution of the mechanical strength of mortars were studied. After analyzing all the aspects, it can be concluded that no significant differences among the different tested catalysts were found.El catalizador de craqueo catalítico (FCC) es un residuo de la industria del petróleo que posee una elevada reactividad puzolánica y en matrices cementicias mejora de manera importante los aspectos mecánicos así como de durabilidad. En este trabajo se realiza un estudio comparativo sobre residuos de catalizador de distintos orígenes, para poder conocer si se pueden utilizar conjuntamente de forma indiscriminada o por el contrario hay que catalogarlos según su origen. Para ello, se realizó un estudio sobre cinco residuos de catalizador de craqueo catalítico distintos, suministrados por diferentes empresas y se estudiaron sus características fisicoquímicas, reactividad puzolánica a través de estudios termogravimétricos y la evolución de las resistencias mecánicas en morteros. Tras analizar todos los aspectos se concluye que no existen diferencias significativas entre los distintos catalizadores empleados

Effect of Temperature on 3D Printing of Commercial Potato Puree

[EN] The temperature and composition of food, during the printing process, maybe a key factor impacting on rheological properties. Currently, there is no evidence of authors analysing the effect of printing temperature on the characteristics of final products. The aim of this paper was to study the printability of potato puree when affected by printing variables, such as printing temperature and the composition of the potato puree. The printing temperature was studied at 10 degrees C, 20 degrees C and 30 degrees C, and the effect of the product composition on the printability was studied by analysing the rheological and textural properties. Viscosity-temperature profiles, flow curves and dynamic oscillation frequency analysis of potato puree were some of the techniques used in rheology analysis. Forward extrusion assays of formulated potato puree were used to study the compression force in the 3D printer. Results showed the formulation with higher content of dehydrated potato puree (38g of dehydrated potato puree in 250mL of whole milk) at a temperature of 30 degrees C were the most stable. The printability increase with the amount of the consistency index and the reduction of behaviour index. The mean force from extrusion test was correlated with printability but the effect of temperature did not help define this parameter.Martínez Monzó, J.; Cárdenas, J.; García-Segovia, P. (2019). Effect of Temperature on 3D Printing of Commercial Potato Puree. Food Biophysics. 14(3):225-234. https://doi.org/10.1007/s11483-019-09576-0S225234143G. Ares, A. Giménez, A. Gámbaro, Instrumental methods to characterize nonoral texture of dulce de leche. J. Texture Stud. 37(5), 553–567 (2006). https://doi.org/10.1111/j.1745-4603.2006.00068.xS. Bhattacharya, N. Vasudha, K.S. Krishna Murthy, Rheology of mustard paste: A controlled stress measurement. J. Food Eng. 41(3), 187–191 (1999). https://doi.org/10.1016/S0260-8774(99)00102-8F. Chuanxing, W. Qi, L. Hui, Z. Quancheng, M. Wang, Effects of pea protein on the properties of potato starch-based 3D printing materials. Int. J. Food Eng. 14(3), 1–10 (2018). https://doi.org/10.1515/ijfe-2017-0297I. Dankar, M. Pujolà, F. El Omar, F. Sepulcre, A. Haddarah, Impact of mechanical and microstructural properties of potato puree-food additive complexes on extrusion-based 3D printing. Food Bioprocess Technol. 11(11), 2021–2031 (2018). https://doi.org/10.1007/s11947-018-2159-5A. Derossi, R. Caporizzi, D. Azzollini, C. Severini, Application of 3D printing for customized food. A case on the development of a fruit-based snack for children. J. Food Eng. 220, 65–75 (2018). https://doi.org/10.1016/j.jfoodeng.2017.05.015F.C. Godoi, S. Prakash, B.R. Bhandari, 3d printing technologies applied for food design: Status and prospects. J. Food Eng. 179, 44–54 (2016). https://doi.org/10.1016/j.jfoodeng.2016.01.025C.A. Hamilton, G. Alici, M. in het Panhuis, 3D printing vegemite and marmite: Redefining “breadboards”. J. Food Eng. 220, 83–88 (2018). https://doi.org/10.1016/j.jfoodeng.2017.01.008S. Holland, T. Foster, W. MacNaughtan, C. Tuck, Design and characterisation of food grade powders and inks for microstructure control using 3D printing. J. Food Eng. 220, 12–19 (2018). https://doi.org/10.1016/j.jfoodeng.2017.06.008H.W. Kim, H. Bae, H.J. Park, Classification of the printability of selected food for 3D printing: Development of an assessment method using hydrocolloids as reference material. J. Food Eng. 215, 23–32 (2017). https://doi.org/10.1016/j.jfoodeng.2017.07.017C. Le Tohic, J.J. O’Sullivan, K.P. Drapala, V. Chartrin, T. Chan, A.P. Morrison, et al., Effect of 3D printing on the structure and textural properties of processed cheese. J. Food Eng. 220, 56–64 (2018). https://doi.org/10.1016/j.jfoodeng.2017.02.003M. Lille, A. Nurmela, E. Nordlund, S. Metsä-Kortelainen, N. Sozer, Applicability of protein and fiber-rich food materials in extrusion-based 3D printing. J. Food Eng. 220, 20–27 (2018). https://doi.org/10.1016/j.jfoodeng.2017.04.034H. Lipson, M. Kurman, Fabricated: The New World of 3D Printing (John Wiley and Sons, Inc, New York, 2013)J.I. Lipton, Printable food: The technology and its application in human health. Curr. Opin. Biotechnol. 44, 198–201 (2017). https://doi.org/10.1016/j.copbio.2016.11.015Z. Liu, M. Zhang, B. Bhandari, Y. Wang, 3D printing: Printing precision and application in food sector. Trends Food Sci. Technol. 69, 83–94 (2017a, September). https://doi.org/10.1016/j.tifs.2017.08.018Liu, Z., Zhang, M., Bhandari, B., & Yang, C. (2017b). Impact of Rheological Properties of Mashed Potatoes on 3D Printing. https://doi.org/10.1016/j.jfoodeng.2017.04.017Z. Liu, M. Zhang, B. Bhandari, C. Yang, Impact of rheological properties of mashed potatoes on 3D printing. J. Food Eng. 220, 76–82 (2018a). https://doi.org/10.1016/j.jfoodeng.2017.04.017Z. Liu, M. Zhang, C.h. Yang, Dual extrusion 3D printing of mashed potatoes/strawberry juice gel. Lwt 96(February), 589–596 (2018b). https://doi.org/10.1016/j.lwt.2018.06.014S. Mantihal, S. Prakash, F.C. Godoi, B. Bhandari, Optimization of chocolate 3D printing by correlating thermal and flow properties with 3D structure modeling. Innovative Food Sci. Emerg. Technol. 44(September), 21–29 (2017). https://doi.org/10.1016/j.ifset.2017.09.012F. Ronda, S. Pérez-Quirce, A. Angioloni, C. Collar, Impact of viscous dietary fibres on the viscoelastic behaviour of gluten-free formulated rice doughs: A fundamental and empirical rheological approach. Food Hydrocoll. 32(2), 252–262 (2013). https://doi.org/10.1016/j.foodhyd.2013.01.014C. Severini, A. Derossi, D. Azzollini, Variables affecting the printability of foods: Preliminary tests on cereal-based products. Innov. Food Sci. Emerg. Technol. 38, 281–291 (2016). https://doi.org/10.1016/j.ifset.2016.10.001C. Severini, A. Derossi, I. Ricci, R. Caporizzi, A. Fiore, Printing a blend of fruit and vegetables. New advances on critical variables and shelf life of 3D edible objects. J. Food Eng. 220, 89–100 (2018). https://doi.org/10.1016/j.jfoodeng.2017.08.025J.R. Stokes, J.H. Telford, Measuring the yield behaviour of structured fluids. J. Non-Newtonian Fluid Mech. 124(1–3 SPEC. ISS), 137–146 (2004). https://doi.org/10.1016/j.jnnfm.2004.09.001J. Sun, Z. Peng, W. Zhou, J.Y.H. Fuh, G.S. Hong, A. Chiu, A review on 3D printing for customized food fabrication. Procedia Manufacturing 1, 308–319 (2015). https://doi.org/10.1016/j.promfg.2015.09.057J. Sun, W. Zhou, L. Yan, D. Huang, L.y. Lin, Extrusion-based food printing for digitalized food design and nutrition control. J. Food Eng. 220, 1–11 (2018). https://doi.org/10.1016/j.jfoodeng.2017.02.028F. Yang, M. Zhang, B. Bhandari, Recent development in 3D food printing. Crit. Rev. 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Electrochemical Oxidation of Small Organic Molecules on Au Nanoparticles with Preferential Surface Orientation

The surface orientation effect on the oxidation of small organic molecules such as methanol, formaldehyde, ethanol, and glycerol has been studied on Au nanoparticles in alkaline medium. Two sets of Au nanoparticles enriched in (100) and (111) facets were synthetized by using colloidal methods in presence of cetyltrimethylammonium bromide. The nanoparticles were physically characterized by using TEM and XRD and electrochemically characterized by using Pb underpotential deposition as a surface-structure probe. It is reported that, although methanol oxidation was similar in both types of nanoparticles, the oxidation of formaldehyde presented a clear surface orientation effect. For this reaction, nanoparticles with (111) preferential orientation presented higher current densities at low potentials, whereas Au(100) nanoparticles exhibited higher activity at potentials more positive than 1.0 V versus RHE. On the other hand, for glycerol and ethanol oxidations, the onset of the reaction was similar in both types of particles, although Au(111) nanoparticles showed higher current densities than the Au(100) ones.P.R. acknowledges financial support from the Netherlands Organization for Scientific Research (NWO) through a VENI grant and the University of Birmingham through a Birmingham Fellowship

Outstanding aspects on the use of spent FCC catalyst in binders

4 pages, 3 fiures, 7 tables.-- En: 1st Spanish National Conference on Advances in Materials Recycling and Eco – Energy Madrid, 12-13 November 2009.-- Editors: F. A. López, F. Puertas, F. J. Alguacil and A. Guerrero.FCC is a waste material from petrochemical plants which has interesting properties for preparing binders. FCC is lightly grey in color, and white FCC-portland cements with L*≥85 can be prepared. FCC reactivity is enhanced by grinding and it is attributed to pozzolanic reaction towards lime. Stratlingite is the main hydrated product from pozzolanic reaction, and CSH and CAH are also formed. Reactivity of FCC is high, and low curing temperature does not affect this contribution to strength in hardened mixtures. Additionally, high strength concrete can be easily prepared, and compressive strength greater 100MPa can be reached. Mixtures with low w/b ratio showed good behaviour in carbonation tests.Authors thank to Ministerio de Ciencia y Tecnología of Spain and FEDER the financial support of MAT 2001-2694 and BIA 2004-0052 projects.Peer reviewe

Use of residual diatomaceous earth as a silica source in geopolymer production

The use of binders as an alternative to Portland cement has gained importance in recent years. Among them, geopolymeric binders, developed by the reaction between an aluminosilicate precursor and a high alkalinity solution, have become one of the most promising alternatives. The activating solution generally comprises waterglass and sodium hydroxide. Since waterglass is the most expensive material and has a high environmental impact, using alternative silica sources will lead to more sustainable binders. Previous studies have successfully used rice husk ash (RHA) as a silica source. This research aims to assess the possibility of using diatomaceous earth (or diatomite) as an alternative silica source, like the previous studies with RHA. Diatomite is a sedimentary rock with a high amorphous silica content formed by fossilized diatom remains. In this work, the geopolymer was obtained using a fluid cracking catalyst residue as the precursor and six different activating solution types prepared with commercial products, residual diatomite (from beer and wine industries) and RHA. The results open a new possible route for the reuse and recovery of diatomaceous earth residue, although the compressive strength results of the mortars were slightly lower than those for mortars prepared with RHA or commercial reagents

NUEVAS TECNOLOGÍAS APLICADAS A LOS CUESTIONARIOS DE FRECUENCIA DE CONSUMO DE ALIMENTOS: UNA PERSPECTIVA ACTUAL

The food frequency questionnaires are widely used in epidemiological researches like dietary assessment method. Traditionally, they have been self-administered in paper but the use of information and communication technologies has led to develop Internet and computerized food frequency questionnaires. It is the objective of this article to offer a global perspective of the new technologies applied to FFQ. It will be presented the purpose of the food frequency questionnaire, the number of strengths of the web-based surveys versus print-surveys and finally, a description of the manuscripts that have used web-based and computerized FFQ.[ES] Resumen Los cuestionarios de frecuencia de consumo de alimentos son muy utilizados en investigaciones epidemiológicas como método para evaluar la dieta. Tradicionalmente, han sido autoadministrados en papel, pero el uso de las tecnologías de la información y la comunicación (TICs) ha permitido desarrollar cuestionarios de frecuencia de consumo de alimentos computerizados y a través de Internet. El objetivo de este artículo es ofrecer una perspectiva actual del uso de las nuevas tecnologías aplicadas al diseño e interpretación de los cuestionarios de frecuencia de consumo de alimentos. En el presente trabajo se resumen los objetivos de los cuestionarios de frecuencia de consumo de alimentos, las ventajas de los cuestionarios autoadministrados por Internet frente a los administrados en papel y finalmente, se describirán diferentes estudios que han usado cuestionarios de frecuencia de consumo de alimentos autoadministrados mediante el uso de ordenador o a través de Internet.Gonzalez-Carrascosa, R. has a predoctoral scholarship from Generalitat Valenciana (Spain).García Segovia, P.; González Carrascosa, R.; Martínez Monzó, J.; Ngo, J.; Serra-Majem, L. (2011). New technologies applied to food frequency questionnaires: a currentperspective. Nutricion Hospitalaria. 26(4):803-806. doi:10.3305/nh.2011.26.4.5154S80380626

Minimization of measuring points for the electric field exposure map generation in indoor environments by means of Kriging interpolation and selective sampling

In a world with increasing systems accessing to radio spectrum, the concern for exposure to electromagnetic fields is growing and therefore it is necessary to check limits in those areas where electromagnetic sources are working. Therefore, radio and exposure maps are continuously being generated, mainly in outdoor areas, by using many interpolation techniques. In this work, Surfer software and Kriging interpolation have been used for the first time to generate an indoor exposure map. A regular measuring mesh has been generated. Elimination of Less Significant Points (ELSP) and Geometrical Elimination of Neighbors (GEN) strategies to reduce the measuring points have been presented and evaluated. Both strategies have been compared to the map generated with all the measurements by calculating the root mean square and mean absolute errors. Results indicate that ELSP method can reduce up to 70% of the mesh measuring points while producing similar exposure maps to the one generated with all the measuring points. GEN, however, produces distorted maps and much higher error indicators even for 50% of eliminated measuring points. As a conclusion, a procedure for reducing the measuring points to generate radio and exposure maps is proposed based on the ELSP method and the Kriging interpolation.This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors

Aggregation Patterns, Sampling Plan, and Economic Injury Levels for the New Citrus Pest Delottococcus aberiae (Hemiptera: Pseudococcidae)

[EN] Delottococcus aberiae De Lotto (Hemiptera: Pseudococcidae) is the latest exotic mealybug species introduced in citrus in the Mediterranean basin. It causes severe distortion and size reduction on developing fruits. Due to its first interaction with citrus, D. aberiae economic thresholds are still unknown for this crop and the current Integrated Pest Management programs have been disrupted. The objectives of this study were to determine the aggregation patterns of D. aberiae in citrus, develop an efficient sampling plan to assess its population density, and calculate its Economic and Economic Environmental Injury Levels (EIL and EEIL, respectively). Twelve and 19 orchards were sampled in 2014 and 2015, respectively. At each orchard, population densities were monitored fortnightly in leaves, twigs, and fruit, and fruit damage was determined at harvest. Our results showed a clumped aggregation of D. aberiae in all organs with no significant differences between generations on fruit. Fruit damage at harvest was strongly correlated with fruit occupation in spring. Based on these results and using chlorpyrifos as the insecticide of reference, the EIL and EEIL were calculated as 7.1 and 12.1% of occupied fruit in spring, respectively. With all this, we recommend sampling 275 fruits using a binomial sampling method or alternatively, 140 fruits with an enumerative method bimonthly between petal fall and July.We would like to thank the owners of the orchards for giving us permission to use their plantations, Aureli Marco and Jesus Marques for finding the orchards, and P. Bru (IVIA) and J. Catalan (IVIA) for their help in sampling. This research was supported by two predoctoral grant (FPU toV. M. and Val I+D to J.P.-R.) from the Spanish Ministry of Education, Culture, and Sport and Generalitat Valenciana, respectively, a national project provided by INIA (Project no. RTA2014-00067) and a European grant (FP7-IAPP324475 'Colbics')Pérez-Rodríguez, J.; Martínez-Blay, V.; Soto Sánchez, AI.; Selfa, J.; Monzó, C.; Urbaneja, A.; Tena, A. (2017). Aggregation Patterns, Sampling Plan, and Economic Injury Levels for the New Citrus Pest Delottococcus aberiae (Hemiptera: Pseudococcidae). Journal of Economic Entomology. 110(6):2699-2706. https://doi.org/10.1093/jee/tox258S269927061106Allsopp, P. G. (1991). Binomial sequential sampling of adult Saccharicoccus sacchari on sugarcane. Entomologia Experimentalis et Applicata, 60(3), 213-218. doi:10.1111/j.1570-7458.1991.tb01540.xBellard, C., Cassey, P., & Blackburn, T. M. (2016). Alien species as a driver of recent extinctions. Biology Letters, 12(2), 20150623. doi:10.1098/rsbl.2015.0623Beltrà, A., Garcia-Marí, F., & Soto, A. (2013). Seasonal Phenology, Spatial Distribution, and Sampling Plan for the Invasive Mealybug Phenacoccus peruvianus (Hemiptera: Pseudococcidae). Journal of Economic Entomology, 106(3), 1486-1494. doi:10.1603/ec13024Boavida, C., Neuenschwander, P., & Schulthess, F. (1992). Spatial distribution ofRastrococcus invadensWilliams (Hom., Pseudococcidae) in mango trees. Journal of Applied Entomology, 114(1-5), 381-391. doi:10.1111/j.1439-0418.1992.tb01141.xBrowning, T. (1959). The long-tailed mealybug, Pseudococcus adonidum (L.) in South Australia. Australian Journal of Agricultural Research, 10(3), 322. doi:10.1071/ar9590322Furness, G. (1976). The Dispersal, Age-Structure and Natural Enemies of the Long-Tailed Mealybug, Pseudococcus Longispinus (Targioni-Tozzetti), in Relation to Sampling and Control. Australian Journal of Zoology, 24(2), 237. doi:10.1071/zo9760237Gaertner, M., Den Breeyen, A., Cang Hui, & Richardson, D. M. (2009). Impacts of alien plant invasions on species richness in Mediterranean-type ecosystems: a meta-analysis. Progress in Physical Geography: Earth and Environment, 33(3), 319-338. doi:10.1177/0309133309341607GEIGER, C. A., & DAANE, K. M. (2001). Seasonal Movement and Distribution of the Grape Mealybug (Homoptera: Pseudococcidae): Developing a Sampling Program for San Joaquin Valley Vineyards. Journal of Economic Entomology, 94(1), 291-301. doi:10.1603/0022-0493-94.1.291Goolsby, J. A., Kirk, A. A., & Meyerdirk, D. E. (2002). SEASONAL PHENOLOGY AND NATURAL ENEMIES OF MACONELLICOCCUS HIRSUTUS (HEMIPTERA: PSEUDOCOCCIDAE) IN AUSTRALIA. Florida Entomologist, 85(3), 494-498. doi:10.1653/0015-4040(2002)085[0494:spaneo]2.0.co;2Groffman, P. M., Baron, J. S., Blett, T., Gold, A. J., Goodman, I., Gunderson, L. H., … Wiens, J. (2006). Ecological Thresholds: The Key to Successful Environmental Management or an Important Concept with No Practical Application? Ecosystems, 9(1), 1-13. doi:10.1007/s10021-003-0142-zHulme, P. E. (2009). Trade, transport and trouble: managing invasive species pathways in an era of globalization. Journal of Applied Ecology, 46(1), 10-18. doi:10.1111/j.1365-2664.2008.01600.xJacas, J. A., & Urbaneja, A. (2010). Biological Control in Citrus in Spain: From Classical to Conservation Biological Control. Integrated Management of Arthropod Pests and Insect Borne Diseases, 61-72. doi:10.1007/978-90-481-8606-8_3Kuno, E. (1991). Sampling and Analysis of Insect Populations. Annual Review of Entomology, 36(1), 285-304. doi:10.1146/annurev.en.36.010191.001441MacDonald, G. K., Brauman, K. A., Sun, S., Carlson, K. M., Cassidy, E. S., Gerber, J. S., & West, P. C. (2015). Rethinking Agricultural Trade Relationships in an Era of Globalization. BioScience, 65(3), 275-289. doi:10.1093/biosci/biu225MAINKA, S. A., & HOWARD, G. W. (2010). Climate change and invasive species: double jeopardy. Integrative Zoology, 5(2), 102-111. doi:10.1111/j.1749-4877.2010.00193.xMartínez-Ferrer, M. T., Ripollés, J. L., & Garcia-Marí, F. (2006). Enumerative and Binomial Sampling Plans for Citrus Mealybug (Homoptera: Pseudococcidae) in Citrus Groves. Journal of Economic Entomology, 99(3), 993-1001. doi:10.1093/jee/99.3.993Meyerson, L. A., & Mooney, H. A. (2007). Invasive alien species in an era of globalization. Frontiers in Ecology and the Environment, 5(4), 199-208. doi:10.1890/1540-9295(2007)5[199:iasiae]2.0.co;2Mgocheki, N., & Addison, P. (2009). Incorporating sampling precision into an action threshold for monitoring ant (Hymenoptera: Formicidae) population levels in vineyards. Crop Protection, 28(3), 257-263. doi:10.1016/j.cropro.2008.10.010Miller, D. R., & Giliomee, J. H. (2011). Systematic Revision of the Mealybug GenusDelottococcusCox & Ben-Dov (Hemiptera: Pseudococcidae). African Entomology, 19(3), 614-640. doi:10.4001/003.019.0306Mudavanhu, P., Addison, P., & Pringle Ken, L. (2011). Monitoring and action threshold determination for the obscure mealybug Pseudococcus viburni (Signoret) (Hemiptera: Pseudococcidae) using pheromone-baited traps. Crop Protection, 30(7), 919-924. doi:10.1016/j.cropro.2011.02.034Navarro-Campos, C., Aguilar, A., & Garcia-Marí, F. (2011). Aggregation pattern, sampling plan, and intervention threshold for Pezothrips kellyanus in citrus groves. Entomologia Experimentalis et Applicata, 142(2), 130-139. doi:10.1111/j.1570-7458.2011.01204.xNestel, D., Cohen, H., Saphir, N., Klein, M., & Mendel, Z. (1995). Spatial Distribution of Scale Insects: Comparative Study Using Taylor’s Power Law. Environmental Entomology, 24(3), 506-512. doi:10.1093/ee/24.3.506PIMENTEL, D., LACH, L., ZUNIGA, R., & MORRISON, D. (2000). Environmental and Economic Costs of Nonindigenous Species in the United States. BioScience, 50(1), 53. doi:10.1641/0006-3568(2000)050[0053:eaecon]2.3.co;2Pimentel, D., Zuniga, R., & Morrison, D. (2005). Update on the environmental and economic costs associated with alien-invasive species in the United States. Ecological Economics, 52(3), 273-288. doi:10.1016/j.ecolecon.2004.10.002Planes, L., Catalán, J., Jaques, J. A., Urbaneja, A., & Tena, A. (2015). Pezothrips kellyanus(Thysanoptera: Thripidae) Nymphs on Orange Fruit: Importance of the Second Generation for Its Management. Florida Entomologist, 98(3), 848-855. doi:10.1653/024.098.0306Roltsch, W. J., Meyerdirk, D. E., Warkentin, R., Andress, E. R., & Carrera, K. (2006). Classical biological control of the pink hibiscus mealybug, Maconellicoccus hirsutus (Green), in southern California. Biological Control, 37(2), 155-166. doi:10.1016/j.biocontrol.2006.01.006Stern, V. M., Smith, R. F., van den Bosch, R., & Hagen, K. S. (1959). The integration of chemical and biological control of the spotted alfalfa aphid: The integrated control concept. Hilgardia, 29(2), 81-101. doi:10.3733/hilg.v29n02p081Sutherland, W. J., Bardsley, S., Bennun, L., Clout, M., Côté, I. M., Depledge, M. H., … Fleishman, E. (2011). Horizon scan of global conservation issues for 2011. Trends in Ecology & Evolution, 26(1), 10-16. doi:10.1016/j.tree.2010.11.002TAYLOR, L. R. (1961). Aggregation, Variance and the Mean. Nature, 189(4766), 732-735. doi:10.1038/189732a0Tena, A., García-Bellón, J., & Urbaneja, A. (2016). Native and naturalized mealybug parasitoids fail to control the new citrus mealybug pest Delottococcus aberiae. Journal of Pest Science, 90(2), 659-667. doi:10.1007/s10340-016-0819-7Waterworth, R. A., Redak, R. A., & Millar, J. G. (2011). Pheromone-Baited Traps for Assessment of Seasonal Activity and Population Densities of Mealybug Species (Hemiptera: Pseudococcidae) in Nurseries Producing Ornamental Plants. Journal of Economic Entomology, 104(2), 555-565. doi:10.1603/ec1031

novel geopolymeric material cured at room temperature

[EN] Alkali activated binders are a new class of binding material with comparable or enhanced performance to Portland cement. These binding materials are obtained by a chemical reaction between an aluminosilicate material and a highly alkaline solution. In most cases, the setting hardening process of this binder is performed at high curing temperatures. In this paper, alkali activated mortars based on vitreous calcium aluminosilicate (VCAS) cured at room temperature are evaluated. Mechanical strength development and microstructural analysis (scanning electron microscopy, thermogravimetric analysis, X-ray diffraction and mercury intrusion porosimetry) of these materials are performed. Mortars yielded compressive strength ¡-89 MPa after 360 days. This is the first time that VCAS is used as aluminosilicate source material in the production of alkali activated mortars cured at room temperature.The authors acknowledge the Ministerio de Ciencia e Innovacio´ n of the Spanish Government (projecto. BIA2011-26947) and the Vitrominerals company for supplying VCAS samples.Mitsuuchi Tashima, M.; Soriano Martínez, L.; Monzó Balbuena, JM.; Borrachero Rosado, MV.; Paya Bernabeu, JJ. (2013). novel geopolymeric material cured at room temperature. Advances in Applied Ceramics. 112:179-183. https://doi.org/10.1179/1743676112Y.0000000056S17918311

Enhanced electrocatalytic activity of Au@Cu core@shell nanoparticles towards CO2 reduction

The development of technologies for the recycling of carbon dioxide into carbon-containing fuels is one of the major challenges in sustainable energy research. Two of the main current limitations are the poor efficiency and fast deactivation of catalysts. Core–shell nanoparticles are promising candidates for enhancing challenging reactions. In this work, Au@Cu core–shell nanoparticles with well-defined surface structures were synthesized and evaluated as catalysts for the electrochemical reduction of carbon dioxide in neutral medium. The activation potential, the product distribution and the long term durability of this catalyst were assessed by electrochemical methods, on-line electrochemical mass spectrometry (OLEMS) and on-line high performance liquid chromatography. Our results show that the catalytic activity and the selectivity can be tweaked as a function of the thickness of Cu shells. We have observed that the Au cubic nanoparticles with 7–8 layers of copper present higher selectivity towards the formation of hydrogen and ethylene; on the other hand, we observed that Au cubic nanoparticles with more than 14 layers of Cu are more selective towards the formation of hydrogen and methane. A trend in the formation of the gaseous products can be also drawn. The H2 and CH4 formation increases with the number of Cu layers, while the formation of ethylene decreases. Formic acid was the only liquid species detected during CO2 reduction. Similar to the gaseous species, the formation of formic acid is strongly dependent on the number of Cu layers on the core@shell nanoparticles. The Au cubic nanoparticles with 7–8 layers of Cu showed the largest conversion of CO2 to formic acid at potentials higher than 0.8 V vs. RHE. The observed trends in reactivity and selectivity are linked to the catalyst composition, surface structure and strain/electronic effects