762 research outputs found

    Photo-induced luminescence

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    The present paper is a critical review dealing with the characteristics, reaction mechanisms and photoproducts, instrumentation and analytical applications of the photo-induced either chemiluminescence or fluorescence. Special attention is paid to the determination of pesticides by continuous-flow methodologies. The paper is divided into several sections covering the most relevant published papers.Catalá Icardo, M.; Martínez Calatayud, JM. (2008). Photo-induced luminescence. Critical Reviews in Analytical Chemistry. 38(2):118-130. doi:10.1080/10408340802039609S118130382Lukasiewicz, R. J., & Fitzgerald, J. M. (1973). Digital integration method for fluorimetric studies of photochemically unstable compounds. Analytical Chemistry, 45(3), 511-517. doi:10.1021/ac60325a002Aaron, J. J., Villafranca, J. E., White, V. R., & Fitzgerald, J. M. (1976). A Quantitative Photochemical-Fluorimetric Method for Measurement of Nonfluorescent Vitamin K1. Applied Spectroscopy, 30(2), 159-162. doi:10.1366/000370276774456408Coly, A., & Aaron, J.-J. (1998). Fluorimetric analysis of pesticides: Methods, recent developments and applications. Talanta, 46(5), 815-843. doi:10.1016/s0039-9140(97)00366-4Aaron, J.-J., & Coly, A. (2000). Luminescence methods in pesticide analysis. Applications to the environment. Analusis, 28(8), 699-709. doi:10.1051/analusis:2000280699Catalá Icardo, M., Garcı́a Mateo, J. V., & Martı́nez Calatayud, J. (2002). Multicommutation as a powerful new analytical tool. TrAC Trends in Analytical Chemistry, 21(5), 366-378. doi:10.1016/s0165-9936(02)00505-8Coly, A. (1999). Photochemically-induced fluorescence determination of sulfonylurea herbicides using micellar media. Talanta, 49(1), 107-117. doi:10.1016/s0039-9140(98)00349-xWerkhoven-Goewie, C. E., Boon, W. M., Praat, A. J. J., Frei, R. W., Brinkman, U. A. T., & Little, C. J. (1982). Preconcentration and LC analysis of chlorophenols, using a styrene-divinyl-benzene copolymeric sorbent and photochemical reaction detection. Chromatographia, 16(1), 53-59. doi:10.1007/bf02258869Scholten, A. H. M. T., Welling, P. L. M., Brinkman, U. A. T., & Frei, R. W. (1980). Use of PTFE coils in post-column photochemical reactors for liquid chromatograph — application to pharmaceuticals. Journal of Chromatography A, 199, 239-248. doi:10.1016/s0021-9673(01)91376-7Batley, G. E. (1984). Use of Teflon components in photochemical reactors. Analytical Chemistry, 56(12), 2261-2262. doi:10.1021/ac00276a066Engelhardt, H., & Neue, U. D. (1982). Reaction detector with three dimensional coiled open tubes in HPLC. Chromatographia, 15(7), 403-408. doi:10.1007/bf02261598Coly, A., & Aaron, J.-J. (1994). Photochemical–spectrofluorimetric method for the determination of several aromatic insecticides. The Analyst, 119(6), 1205-1209. doi:10.1039/an9941901205ALBERTGARCIA, J., ICARDO, M., & CALATAYUD, J. (2006). Analytical strategy photodegradation/chemiluminescence/continuous-flow multicommutation methodology for the determination of the herbicide Propanil. Talanta, 69(3), 608-614. doi:10.1016/j.talanta.2005.10.044Coly, A., & Aaron, J.-J. (1998). Cyclodextrin-enhanced fluorescence and photochemically-induced fluorescence determination of five aromatic pesticides in water. Analytica Chimica Acta, 360(1-3), 129-141. doi:10.1016/s0003-2670(97)00721-6Poulsen, J. B., Birks, K. S., Gandelman, M. S., & Birks, J. W. (1986). Crocheted PTFE reactors for post-column photochemistry in HPLC. Chromatographia, 22(7-12), 231-234. doi:10.1007/bf02268764Martínez Calatayud, J. 1988.Flow Injection Analysis of Pharmaceuticals. Automation in the Laboratory, 458London, UK: Taylor and Francis Ltd.Palomeque, M., Garcı́a Bautista, J. ., Catalá Icardo, M., Garcı́a Mateo, J. ., & Martı́nez Calatayud, J. (2004). Photochemical-chemiluminometric determination of aldicarb in a fully automated multicommutation based flow-assembly. Analytica Chimica Acta, 512(1), 149-156. doi:10.1016/j.aca.2004.02.031Chivulescu, A., Catalá-Icardo, M., Garcı́a Mateo, J. ., & Martı́nez Calatayud, J. (2004). New flow-multicommutation method for the photo-chemiluminometric determination of the carbamate pesticide asulam. Analytica Chimica Acta, 519(1), 113-120. doi:10.1016/j.aca.2004.05.046PAWLICOVÁ, Z., ALBERT-GARCÍA, J. R., SAHUQUILLO, I., GARCÍA MATEO, J. V., CATALÁ ICARDO, M., & MARTÍNEZ CALATAYUD, J. (2006). Chemiluminescent Determination of the Pesticide Bromoxynil by On-line Photodegradation in a Flow-Injection System. Analytical Sciences, 22(1), 29-34. doi:10.2116/analsci.22.29Mervartová, K., Calatayud, J. M., & Icardo, M. C. (2005). A Fully Automated Assembly Using Solenoid Valves for the Photodegradation and Chemiluminometric Determination of the Herbicide Chlorsulfuron. Analytical Letters, 38(1), 179-194. doi:10.1081/al-200043477Coly, A., & Aaron, J.-J. (1999). Sensitive and rapid flow injection analysis of sulfonylurea herbicides in water with micellar-enhanced photochemically induced fluorescence detection. Analytica Chimica Acta, 392(2-3), 255-264. doi:10.1016/s0003-2670(99)00229-9Garcı́a-Campaña, A. M., Aaron, J.-J., & Bosque-Sendra, J. M. (2001). Micellar-enhanced photochemically induced fluorescence detection of chlorophenoxyacid herbicides. Flow injection analysis of mecoprop and 2,4-dichlorophenoxyacetic acid. Talanta, 55(3), 531-539. doi:10.1016/s0039-9140(01)00470-2Parrilla�V�zquez, P., Gil�Garc�a, M. D., Barranco�Mart�nez, D., & Mart�nez�Galera, M. (2005). Application of coupled-column liquid chromatography combined with post-column photochemically induced fluorimetry derivatization and fluorescence detection to the determination of pyrethroid insecticides in vegetable samples. Analytical and Bioanalytical Chemistry, 381(6), 1217-1225. doi:10.1007/s00216-004-3043-xIrace-Guigand, S., Leverend, E., Seye, M. D. G., & Aaron, J. J. (2005). A new on-line micellar-enhanced photochemically-induced fluorescence method for determination of phenylurea herbicide residues in water. Luminescence, 20(3), 138-142. doi:10.1002/bio.817Liu, L., & Guo, Q.-X. (2002). Journal of Inclusion Phenomena and Macrocyclic Chemistry, 42(1/2), 1-14. doi:10.1023/a:1014520830813Frankewich, R. P., Thimmaiah, K. N., & Hinze, W. L. (1991). Evaluation of the relative effectiveness of different water-soluble .beta.-cyclodextrin media to function as fluorescence enhancement agents. Analytical Chemistry, 63(24), 2924-2933. doi:10.1021/ac00024a023Patel, B. M., Moye, H. A., & Weinberger, R. (1991). Postcolumn formation of fluorophores from nitrogenous pesticides by UV photolysis. Talanta, 38(8), 913-922. doi:10.1016/0039-9140(91)80272-2Torrents, A., Anderson, B. G., Bilboulian, S., Johnson, W. E., & Hapeman, C. J. (1997). Atrazine Photolysis:  Mechanistic Investigations of Direct and Nitrate-Mediated Hydroxy Radical Processes and the Influence of Dissolved Organic Carbon from the Chesapeake Bay. Environmental Science & Technology, 31(5), 1476-1482. doi:10.1021/es9607289Dogliotti, L., & Hayon, E. (1967). Flash photolysis of per[oxydi]sulfate ions in aqueous solutions. The sulfate and ozonide radical anions. The Journal of Physical Chemistry, 71(8), 2511-2516. doi:10.1021/j100867a019Pérez-Ruiz, T. (2001). Flow injection determination of methamidophos using online photo-oxidation and fluorimetric detection. Talanta, 54(5), 989-995. doi:10.1016/s0039-9140(01)00369-1Pérez-Ruiz, T., Martínez-Lozano, C., Tomás, V., & Martín, J. (2002). FLOW INJECTION SPECTROFLUORIMETRIC DETERMINATION OF MALATHION IN ENVIRONMENTAL SAMPLES USING ON-LINE PHOTOOXIDATION. Analytical Letters, 35(7), 1239-1250. doi:10.1081/al-120005976Pérez-Ruiz, T., Martínez-Lozano, C., Tomás, V., & Martín, J. (2002). Fluorimetric determination of arsanilic acid by flow-injection analysis using on-line photo-oxidation. Analytical and Bioanalytical Chemistry, 372(2), 387-390. doi:10.1007/s00216-001-1173-yPérez-Ruiz, T., Martı́nez-Lozano, C., Tomás, V., & Martı́n, J. (2001). Flow-injection fluorimetric method for the determination of dimethylarsinic acid using on-line photo-oxidation. Analytica Chimica Acta, 447(1-2), 229-235. doi:10.1016/s0003-2670(01)01299-5Baird, C. 1995.Environmental Chemistry, 509–510. New York: W. H. Freeman and Company.Bauer, R., & Fallmann, H. (1997). The Photo-Fenton Oxidation — A cheap and efficient wastewater treatment method. Research on Chemical Intermediates, 23(4), 341-354. doi:10.1163/156856797x00565Huston, P. L., & Pignatello, J. J. (1999). Degradation of selected pesticide active ingredients and commercial formulations in water by the photo-assisted Fenton reaction. Water Research, 33(5), 1238-1246. doi:10.1016/s0043-1354(98)00330-3CATASTINI, C., SARAKHA, M., MAILHOT, G., & BOLTE, M. (2002). Iron (III) aquacomplexes as effective photocatalysts for the degradation of pesticides in homogeneous aqueous solutions. The Science of The Total Environment, 298(1-3), 219-228. doi:10.1016/s0048-9697(02)00219-xZepp, R. G., Schlotzhauer, P. F., & Sink, R. M. (1985). Photosensitized transformations involving electronic energy transfer in natural waters: role of humic substances. Environmental Science & Technology, 19(1), 74-81. doi:10.1021/es00131a008Pérez-Ruiz, T., Lozano, C. M., Tomás, V., & Martı́n, J. (2003). Flow injection chemiluminescence determination of carbaryl using photolytic decomposition and photogenerated tris (2,2′-bipyridyl)ruthenium(III). Analytica Chimica Acta, 476(1), 141-148. doi:10.1016/s0003-2670(02)01355-7Pérez-Ruiz, T., Martínez-Lozano, C., Tomás, V., & Martín, J. (2002). Chemiluminescence determination of carbofuran and promecarb by flow injection analysis using two photochemical reactions. The Analyst, 127(11), 1526-1530. doi:10.1039/b207460pMiles, C. J., & Moye, H. A. (1988). Postcolumn photolysis of pesticides for fluorometric determination by high-performance liquid chromatography. Analytical Chemistry, 60(3), 220-226. doi:10.1021/ac00154a007Soto-Chinchilla, J. J., Garcı́a-Campaña, A. M., Gámiz-Gracia, L., Cuadros-Rodrı́guez, L., & Vidal, J. L. M. (2004). Determination of a N-methylcarbamate pesticide in environmental samples based on the application of photodecomposition and peroxyoxalate chemiluminescent detection. Analytica Chimica Acta, 524(1-2), 235-240. doi:10.1016/j.aca.2004.05.084And, S. T., & Aaron, J. J. (1987). Fluorimetric Determination of Non-Fluorescent Dinitroaniline Derivative Herbicides, Using the Photoreduction of Anthraquinone - 2, 6-Disulfonate. Analytical Letters, 20(12), 1995-2009. doi:10.1080/00032718708078040Miles, C. J., & Anson Moye, H. (1987). High performance liquid chromatography with post-column photolysis of pesticides for generation of fluorophores. Chromatographia, 24(1), 628-632. doi:10.1007/bf02688556Patel, B. M., Moye, H. A., & Weinberger, R. (1990). Formation of fluorophores from nitrogenous pesticides by photolysis and reaction with OPA-2-mercaptoethanol for fluorescence detection in liquid chromatography. Journal of Agricultural and Food Chemistry, 38(1), 126-134. doi:10.1021/jf00091a027Durand, G., Barceló, D., Albaigés, J., & Mansour, M. (1990). Utilisation of liquid chromatography in aquatic photodegradation studies of pesticides: A comparison between distilled water and seawater. Chromatographia, 29(3-4), 120-124. doi:10.1007/bf02268696Rosen, J. D., Strusz, R. F., & Still, C. C. (1969). Photolysis of phenylurea herbicides. Journal of Agricultural and Food Chemistry, 17(2), 206-207. doi:10.1021/jf60162a046Lay, J. P., Klein, W., & Korte, F. (1975). Beiträge zur ökologischen Chemie C. Chemosphere, 4(3), 161-168. doi:10.1016/0045-6535(75)90094-6Tanaka, F. S., Hoffer, B. L., & Wien, R. G. (1985). Detection of halogenated biphenyls from sunlight photolysis of chlorinated herbicides in aqueous solution. Pesticide Science, 16(3), 265-270. doi:10.1002/ps.2780160309Pelizzetti, E., Maurino, V., Minero, C., Carlin, V., Tosato, M. L., Pramauro, E., & Zerbinati, O. (1990). Photocatalytic degradation of atrazine and other s-triazine herbicides. Environmental Science & Technology, 24(10), 1559-1565. doi:10.1021/es00080a016Chukwudebe, A., March, R. B., Othman, M., & Fukuto, T. R. (1989). Formation of trialkyl phosphorothioate esters from organophosphorus insecticides after exposure to either ultraviolet light or sunlight. Journal of Agricultural and Food Chemistry, 37(2), 539-545. doi:10.1021/jf00086a058Durand, G., De Bertrand, N., & Barceló, D. (1991). Applications of thermospray liquid chromatography-mass spectrometry in photochemical studies of pesticides in water. Journal of Chromatography A, 554(1-2), 233-250. doi:10.1016/s0021-9673(01)88453-3WOLFE, N., ZEPP, R., & PARIS, D. (1978). Carbaryl, propham and chlorpropham: A comparison of the rates of hydrolysis and photolysis with the rate of biolysis. Water Research, 12(8), 565-571. doi:10.1016/0043-1354(78)90134-3Samanidou, V., Fytianos, K., Pfister, G., & Bahadir, M. (1988). Photochemical decomposition of carbamate pesticides in natural waters of northern Greece. Science of The Total Environment, 76(1), 85-92. doi:10.1016/0048-9697(88)90287-2Konstantinou, I. K., Sakkas, V. A., & Albanis, T. A. (2001). Photocatalytic degradation of the herbicides propanil and molinate over aqueous TiO2 suspensions: identification of intermediates and the reaction pathway. Applied Catalysis B: Environmental, 34(3), 227-239. doi:10.1016/s0926-3373(01)00218-1Machado, F., Collin, L., & Boule, P. (1995). Photolysis of bromoxynil (3,5-dibromo-4-hydroxybenzonitrile) in aqueous solution. Pesticide Science, 45(2), 107-110. doi:10.1002/ps.2780450203Boule, P., Guyon, C., & Lemaire, J. (1982). Photochemistry and environment IV- Photochemical behaviour of monochlorophenols in dilute aqueous solution. Chemosphere, 11(12), 1179-1188. doi:10.1016/0045-6535(82)90031-5Almansa Lopez, E. (2003). Simultaneous quantification of chlorophenoxyacid herbicides based on time-resolved photochemical derivatization to induce fluorescence in micellar medium. Talanta, 60(2-3), 355-367. doi:10.1016/s0039-9140(03)00109-7Garcia, L. F., Eremin, S., & Aaron, J.-J. (1996). Flow-Injection Analysis of Chlorophenoxyacid Herbicides using Photochemically Induced Fluorescence Detectiona. Analytical Letters, 29(8), 1447-1461. doi:10.1080/00032719608001493Lahuerta Zamora, L., Fuster Mestre, Y., Duart, M. J., Antón Fos, G. M., García Doménech, R., Gálvez Álvarez, J., & Martínez Calatayud, J. (2001). Prediction of the Chemiluminescent Behavior of Pharmaceuticals and Pesticides. Analytical Chemistry, 73(17), 4301-4306. doi:10.1021/ac010133iGómez-Taylor Corominas, B. (2003). Prediction of the chemiluminescent behaviour of phenols and polyphenols. Talanta, 60(2-3), 623-628. doi:10.1016/s0039-9140(03)00105-xPolo Martí, E., Catalá Icardo, M., Lahuerta Zamora, L., Antón Fos, G. M., & Martínez Calatayud, J. (2004). Theoretical prediction of the chemiluminescence behaviour of the ergot alkaloids. Analytica Chimica Acta, 527(2), 177-186. doi:10.1016/j.aca.2004.07.026P�rez-Ruiz, T., Mart�nez-Lozano, C., Tom�s, V., Sanz, A., & Garre, R. (2003). Flow Injection Spectrophotometric Determination of Ferbam Based on a Photochemical Reaction. Microchimica Acta, 142(4), 231-235. doi:10.1007/s00604-003-0027-zRoda, A., Rauch, P., Ferri, E., Girotti, S., Ghini, S., Carrea, G., & Bovara, R. (1994). Chemiluminescent flow sensor for the determination of Paraoxon and Aldicarb pesticides. 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    Heterogenization of a Chiral Molecular Catalyst on a Carbon Support using Tryptophan as Anchor Molecule

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    The (R,R)‐RhDuphos chiral catalyst has been heterogenized on the surface of a carbon material with the aid of L‐tryptophan (Trp) as anchor molecule. Trp is effectively adsorbed on the carbon surface through its arene unit and is able to coordinate Rh by means of the carbonyl and amine functional groups. The chiral hybrid catalysts prepared are very active for the asymmetric hydrogenation of 2‐methyl‐acetamidoacrylate with an acceptable enantioselectivity. Besides, when prepared with a high Tpr/Rh ratio they have shown to be stable and reusable.The authors thank funding to the Spanish Ministry of Science, Innovation and Universities, Generalitat Valenciana and FEDER, projects of reference RTI2018-095291-B-I00 and PROMETEO/2018/076 and also University of Alicante (, project VIGROB-136)

    Synthesis and Photophysical Properties of Cycloplatinated(II) Complexes Bearing Isocyanide and Alkynyl Ligands

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    Cyclometalated platinum(II) complexes havegained increasing interest during the last yearsdue to their rich chemistry and uniqueluminescent properties, making them suitablefor light emitting diodes (OLEDs),photocatalysis, bioimaging or chemicalsensors. However, there are very scarceantecedents of heteroleptic cycloplatinated(II)compounds with isocyanide and alkynylligands.1To expand this research, we aimed to prepare anew family of luminescent cycloplatinatedcomplexes with 2-(2,4-difluorophenyl)pyridine(dfppy, a) and 4-(2-pyridyl)benzaldehyde(ppy-CHO, b) as cyclometalating ligands. Thealkynyl/tert-butyl isocyanide complexes[Pt(C^N)(CCR)(CNtBu)], bearing 4-ethynylanisole (2) and 2-ethynylthiophene (3)have obtained from the chloride derivatives[Pt(C^N)Cl(CNtBu)] (C^N = dfppy 1a, ppy-CHO 1b) using the Sonogashira protocol.These systems have been designed by takinginto account features that could make thesecomplexes interesting in biological studies.The complexes have been fully characterizedusing NMR spectroscopy together with X-raydiffraction. Their optical properties have beenstudied in detail and interpreted with the helpof TD-DFT calculations. The dfppy derivativesexhibit a mechanochromic behaviour, relatedto their strong tendency to form stackingstructures or aggregates by Pt···Pt and/or ···interactions

    Insight into the immobilization of ionic liquids on porous carbons

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    Very different carbon materials have been used as support in the preparation of supported ionic liquid phase samples (SILP). Some of them have been oxidized, either strongly (with ammonium persulfate solution) or weakly (with air at 300 °C, 2 h). The purpose is to establish which properties of the supports (e.g., porosity -volume and type-, surface area, oxygen surface chemistry and morphology) determine the IL adsorption capacity and the stability (immobilization) of the supported IL phase. The ionic liquid used in this work is 1-butyl-3-methyl-imidazolium hexafluorophosphate ([bmim][PF6]). For each support, samples with different amounts of ionic liquid have been prepared. The maximum IL that can be loaded depends mainly on the total pore volume of the supports. For comparable pore volumes, the porosity type and the oxygen surface content have no influence on the IL loading. The supported IL fills most of the pores, leaving some blocked porosity. The stability of the supported IL phase (especially important for its subsequent use in catalysis) has been tested in water under general hydrogenation conditions (60 °C and 10 bar H2). In general, leaching is low but it increases with the amount of IL loaded and with the oxidation treatments of the supports.The authors thank the Spanish government for the project MAT2012-32832. M.R.B thanks the FPI scholarship grant associated to project MAT2009-07150

    "Los dioses practican juegos de mesa": un motivo del cine mitológico y sus antecedentes clásicos

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    La principal convención de la epopeya clásica es el desdoblamiento de plano en dos niveles: el Olimpo y la tierra. Los dioses, desde el Olimpo, intervienen en los asuntos humanos que se desarrollan en la tierra. En algunas películas de tema mitológico, como Jasón y los Argonautas (1963) y Furia de Titanes (1981), aparece un motivo peculiar que se incardina dentro de esa convención general: los dioses (destacadamente Zeus) practican un juego de mesa en el que las piezas representan a los humanos. Este trabajo rastrea los antecedentes clásicos de este motivo fílmico, así como las conexiones antropológicas y culturales del mismo, con vistas a sugerir posibles fuentes de los guionistas y a examinar su motivación

    New Genus and First Record of Hybotinae (Diptera: Empidoidea: Hybotidae) in Middle Miocene Dominican Amber.

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    A new fossil genus of the family Hybotidae is described, based on male and female specimens. The new genus is monotypic: Syneproctus caridadi gen. et sp. nov. It belongs to the subfamily Hybotinae and shares some characters with the extant genera Syneches Walker, 1852, Stenoproctus Loew, 1858 and Chillcottomyia Saigusa, 1986; however, the differences, principally in the wing venation (shortened cua cell, horizontal m-cu crossvein) and sclerotized mouthparts, support the description of a new genus. This is the first description of a new taxon of the subfamily Hybotinae from specimens preserved in Dominican amber

    Unravelling the mystery of 'Madagascar copal': Age, origin and preservation of a Recent resin

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    The loss of biodiversity during the Anthropocene is a constant topic of discussion, especially in the top biodiversity hotspots, such as Madagascar. In this regard, the study of preserved organisms through time, like those included in 'Madagascar copal', is of relevance. 'Madagascar copal' originated from the leguminous tree Hymenaea verrucosa, which produced and produces resin abundantly. In the last 20 years, interest has focused on the scientific study of its biological inclusions, mainly arthropods, described in dozens of publications. The age and origin of the deposits of 'Madagascar copal' have not yet been resolved. Our objectives are to determine its age and geographical origin, and thus increase its scientific value as a source of biological/palaeobiological information. Although Hymenaea was established in Madagascar during the Miocene, we did not find geological deposits of copal or amber in the island. It is plausible that the evolution of those deposits was negatively conditioned by the type of soil, by the climate, and by the development of soil/litter microorganisms, which inhibit preservation of the resin pieces in the litter and subsoil over 300 years. Our results indicate that 'Madagascar copal' is a Recent resin, up to a few hundred years old, that originated from Hymenaea trees growing in the lowland coastal forests, one of the most endangered ecosystems in the world. The included and preserved biota is representative of that ecosystem today and during historical times. Inclusions in this Recent resin do not have the palaeontological significance that has been mistakenly attributed to them, but they do have relevant implications for studies regarding Anthropocene biodiversity loss in this hottest hotspot

    A revised definition for copal and its significance for palaeontological and Anthropocene biodiversity‑loss studies

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    The early fossilization steps of natural resins and associated terminology are a subject of constant debate. Copal and resin are archives of palaeontological and historical information, and their study is critical to the discovery of new and/or recently extinct species and to trace changes in forests during the Holocene. For such studies, a clear, suitable definition for copal is vital and is herein established. We propose an age range for copal (2.58 Ma¿1760 AD), including Pleistocene and Holocene copals, and the novel term 'Defaunation resin', defined as resin produced after the commencement of the Industrial Revolution. Defaunation resin is differentiated from Holocene copal as it was produced during a period of intense human transformative activities. Additionally, the 'Latest Amber Bioinclusions Gap' (LABG) since the late Miocene to the end of the Pleistocene is hereby newly defined, and is characterized by its virtual absence of bioinclusions and the consequent lack of palaeontological information, which in part explains the historical differentiation between amber and copal. Crucial time intervals in the study of resin production, and of the biodiversity that could be contained, are now clarified, providing a framework for and focusing future research on bioinclusions preserved in copal and resin

    Cuando la memoria es una condena: análisis narratológico de "Funes el memorioso" de Borges

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    de Jorge Luis Borges. A partir del estudio de la configuración de los subcódigoslitera- rios, tanto en el nivel de la historia como del discurso, se propone una semántica del texto en el marco de los intereses narrativos del autor. Para el hombre normal, vivir consiste en forjarse un mundo simplificado; el hombre que no se conforma con esta “normalidad”, como el protagonista del relato, cuya memoria de los detalles le impi- de abstraer conceptos, incurre en hybris y está abocado a su autodestrucción.Borges is offered. It is demonstrated that all the literary codes of the tale, both at the story- and at the discourse-level, work conjointly to bestow a meaning on the text within the frame of Borges’ usuarequires to forge a simplified world. The main character in the story, who is unable to build abstract concepts due to his extraordinary memory of details, doesn’t fit into the “normal box”, being thus guilty of hybris and doomed t

    Background harmonic distortion measurement at power networks with wind farms

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    Standard IEC 61400-21 specifies that background voltage distortion must be lower than the threshold limits specified in standards. However, this background distortion information is not used for calculating the real harmonic emission from the wind turbine leading to misleading voltage harmonics assessment from the wind turbine. In this paper a methodology for assessing the real harmonic emission from wind turbines is proposed based on current and voltage measurements where the background harmonic distortion at the Point of Common Coupling is considered
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