50 research outputs found
Co-crystal of suberic acid and 1,2-bis(4-pyridyl)ethane: A new case of packing polymorphism
The polymorphic behaviour of a co-crystal composed of neutral suberic acid and 1, 2-bis(4-pyridyl)ethane is reported. A multidisciplinary approach has been employed, using thermal analysis methods (differential scanning calorimetry and polarized light thermomicroscopy), spectroscopic methods (infrared spectroscopy) and X-ray single crystal and powder diffraction. Two new polymorphs, I and III; have been identified, and for one of them the crystal structure has been elucidated and compared to that of a known polymorph, form II, showing that the assembling of the molecules in chains via H-bonds is a common feature of both polymorphs. Polymorph II, obtained by crystallization from an aqueous or ethanol solution or by grinding, undergoes a solid-solid transition to polymorph I, which melts at 180.5 °C. Upon cooling from the melt, polymorph I is obtained, and a solid-solid transformation also occurs, to polymorph III''. Polymorph III was obtained serendipitously in an attempt to prepare a Nd(III) complex. The relative stability of the three polymorphic forms was established
Crude and refined oils from Elaeis guineensis: Facile characterization by FTIR and thermal analysis techniques
From an industrial perspective, fast characterization of raw materials provides an important tool for preventing manufacturing problems and contributes to assure the quality of the final products. In this work, several fast, cheap, and simple methods (Fourier transform infrared spectroscopy (FTIR) and various thermoanalytical techniques) were used for screening and characterization of crude and refined palm oils and other palm-derived products. The FTIR spectra allowed for ready distinction between mesocarp-derived products and those obtained from the kernel. The same applied to high-temperature differential scanning calorimetry (DSC) and differential thermal analysis (DTA) thermograms and the low-temperature DSC curves, in which the peak values and the presence or absence of certain peaks also permitted to differentiate among the various oils and fractions. Correspondences of mesocarp-derived oils with olein and kernel-derived oils with stearin were confirmed by both analytical methods and from the crystallization study. The relationship between the triglyceride composition and the FTIR and thermal profiles of the various palm-derived products has potential to be utilized as a facile quality control method in mill plants and laboratories
Vibrational and thermal studies of essential oils derived from Cistus ladanifer and Erica arborea shrubs
Producción CientíficaEssential oils from the two most representative shrub species from the Iberian Peninsula (namely Cistus ladanifer L. and Erica arborea L.) have been characterized by Fourier transform infrared spectroscopy (FTIR) and thermoanalytical techniques (TG/DTG and DSC). Vibrational spectra have been compared with those of components of the plants, and with those of oils, gums and resins from other species. The different content in terpenoids of C. ladanifer oil (mainly mono- and sesquiterpenoids) and E. arborea oil (mainly triterpenoids) is reflected in the ATR-FTIR by the position of the bands at around 2873 cm−1, 1730 cm−1 and 1678 cm−1. As regards their thermal behavior, C. ladanifer-derived oil evinced higher thermal stability than that of obtained from E. arborea: the pyrolysis of the former was sensitized at 210°C, whereas for the later it occurred at 143°C. These temperatures are high enough to state that thermolabile constituents such as terpenoids are conserved in the hydrodistillation and that this extraction process ensures the recovery of the main constituents of both essential oils.Programa LIFE+ de la Unión Europea (Proyecto LIFE11 ENV/ ES/000535)Fundação para a Ciência e a Tecnologia (FCT) (Proyecto UID/QUI/UI0313/2013
Genetic variation of cork oak a tool for improving regeneration of cork oak woodlands
The European Academies' Science Advisory Council (2017) reports that the Mediterranean forest
is already being affected by climate change (IPCC, 2014) and cork oak woodlands are particularly vulnerable
to high-end climate scenarios that go above the Paris Agreement 2° C increase in temperature. Since longer,
more frequent, and more intense drought periods are expected, stress caused by the expansion of arid and
semi-arid climate will affect the species distribution. Consequently, not only established stands may be prone
to tree mortality, but also the current reforestation effort may be jeopardized by low survival rates attributed
to the use of unsuitable genetic material.
It is expected that, through genetic adaptation and/or phenotypic plasticity, cork oak populations may have
developed significant differences in fitness and the traits related to it. In this context, provenance and
progeny trials are the best resource of material to assess the variability between and within populations from
seed sources sampled in a wide range of locations (stands) covering the geographical distribution of the
species. Profiting from the multi-locality provenance and progeny trials belonging to a Network, established
in 1998, in the initiative frame of FAIR I CT 0202 for the evaluation of genetic resources of cork oak for
appropriate use in breeding and gene conservation strategies”, where 35 cork oak populations covering all
the natural distribution area are represented. The provenance trials that where set up in different countries
are entering now the age of first debarking and this should allow to have first data about the influence of
genetics on production by different site qualities. INCREDIBLE project should document this knowledgeFAIR I CT 0202info:eu-repo/semantics/publishedVersio
Ensaios de proveniência de sobreiro (Quercus suber) - resultados aos cinco anos
Congresso Florestal Nacional: a floresta e as gentes - Actas das ComunicaçõesA adaptabilidade do sobreiro às condições ambientais está pouco estudada e o uso de recursos genéticos inapropriados é uma das causas do insucesso de reflorestação tanto no curto como no longo prazo. Os resultados do esforço de florestação com sobreiro têm sido muito díspares, com valores médios de sobrevivência de 50% que oscilam entre o insucesso total e uma sobrevivência que, em alguns casos, atinge os 100%. A eventual alteração climática acentua a necessidade da utilização de material de reprodução adaptado, como meio de promover a sustentabilidade do montado e das florestas de sobreiro. A caracterização dos recursos genéticos desta espécie poderá contribuir também para a viabilidade económica e ambiental deste sistema ao identificar as populações mais adaptadas e os indivíduos produtores de melhor cortiça.
A rede de ensaios de proveniência de sobreiro instalados em 1998, no âmbito da acção concertada “FAIR 1CT 95 0202”, onde estão representadas 35 populações cobrindo toda a sua área de distribuição natural são um excelente instrumento para a avaliação da adaptabilidade. Ainda que as respostas ao nível da qualidade da cortiça só possam ser obtidas tardiamente, o acompanhamento de parâmetros adaptativos ao longo do crescimento das árvores é importante e poderá fornecer informação relevante para a compreensão do funcionamento do sistema. Nesta comunicação apresentam-se os resultados obtidos, 5 anos após a instalação, nos ensaios de proveniência estabelecidos na Mata Nacional das Virtudes e no Monte da Fava relativamente a características adaptativas tais como: a sobrevivência, a eficiência do uso da água, o abrolhamento dos gomos foliares e o crescimento. Ao nível da sobrevivência as populações de origem francesa revelaram-se as menos adaptadas em ambos os locais. Quanto à altura, as 35 populações apresentaram crescimentos significativamente diferentes entre si nos dois ensaios, tendo as populações marroquinas registado os valores mais elevados. Relativamente ao abrolhamento dos gomos foliares observou-se um comportamento semelhante em termos das populações mais tardias e mais temporãs em ambos os ensaios. Geograficamente as primeiras localizam-se numa área mais ocidental da zona de distribuição natural da espécie enquanto que populações mais temporãs, com comportamento significativamente diferente das anteriores são originárias da região mais oriental
Provenance behavior in the cork-oak International network trials fair 202
The international network of provenance trials in cork-oak was established as a result of the EU Concerted Action FAIR 202, 1995-2000. 34 provenances were selected in the natural range of cork oak and trials were established in 1996/97 in France, Italy, Portugal, Tunisia and Spain. This study compares the behavior of provenances in the trials of Grighini (Sardinia), Monte Fava and Quinta da Nogueira (Portugal), Monfrague (Spain), Les Maures (France) and Tebabe (Tunisia). Observations on total height (Ht) and diameter at beast height (DBH) are used to compare and assess adaptation within sites and among sites. Climate at the provenance site seed collection and at trials sites is used to characterize the behavior of provenances. The results reveal that the provenances, ES 5 (1063 mm), IT16 (910 mm), IT12 (937 mm), 937, TU32 (948 mm), FR2 (958 mm, FR1 (963 mm, MA31 (970 mm), ES8 (993 mm) are able to adapt and show good growth under conditions of decrease of total annual rainfall and strong decrease in case of TU33 (1610mm), MA27 (1280 mm). On the other hand provenances coming from sites of low precipitation not always show relevant performance in sites of higher precipitation as IT14 (448 mm), ES10 (455 mm), MA29 (479 mm). These results are discussed in the impact climate change (CC) may have in adaptation and evolution of cork oak. Our results show that cork oak will not face serious threats if drought increases in the Mediterranean region, since some populations are showing capable to cope successfully with decrease of total precipitation. The ongoing results from the cork-oak international network trials FAIR 202 show the importance of this line of research and the need to establish harmonized criteria on data collection to enhance the comparability. As cork quality is a key issue on cork-oak economic sustainability it is critical to establish harmonized criteria in cork harvesting for further studies to compare cork quality with special reference for the assessment of the genetic control of cork production and heritability.info:eu-repo/semantics/publishedVersio
Évaluation préliminaire des essais de provenances de chêne-liège et perspectives de recherche
Le réseau international des essais de provenance et de descendance de chêne-liège (établie dans le cadre du projet Action Concertée FAIR CT 95-202 “European network for the evaluation of genetic resources of cork oak for appropriate use in breeding and gene conservation strategies” financé par l’Union Européenne) constitue un matériel vivant unique pour la recherche, qu’elle soit appliquée, ou fondamental, sur l’espèce.
Les essais génétiques ont été réalisés sur une base méthodologique harmonisée au niveau des plants utilisés (tous les plants ont été élevées dans une même pépinière au Portugal) et sur terrain un même dispositif expérimental a été suivi.
En 1997/98, 13 essais de provenances ont été établis. Ceux ayant réussi sont situés en Espagne (2), France (1), Italie (3), Portugal (3) et Tunisie (1). Concernent les essais de descendances il existe 4 des 5 initiales - Espagne (1), Portugal (2) et Tunisie (1).
Dans ce travail nous présentons quelques résultats du comportement des provenances à travers des caractéristiques adaptatifs tels que la survie, l’efficacité d’utilisation de l’eau et des études de génomique. Nous avons procédé à la comparaison de chaque provenance dans les essais - niveau horizontal- et à la comparaison de chaque provenance entre les essais - niveau vertical afin de discuter la plasticité phénotypique et l’interaction génotype X environnement.
Les données disponibles pour hauteur en 2006 montre des différences de comportement entre provenances et entre les essais. Par exemple, les provenances du Maroc montre une croissance supérieure dans l’essai plus au Sud au Portugal et aussi dans un essai en Espagne. Pour l’essai de Sardaigne les meilleures provenances sont de Tunisie et d’Espagne.
A la fin on discute sur les avantages des essais comme matériel vivant dénominateur commun pour une recherche avancée, multidisciplinaire, synergétique, transnational et concertée. Les perspectives pour la recherche sur les grands thèmes tels que la gestion durable du chêne-liège, notamment la sélection, amélioration génétique, adaptation aux changements globaux, fluxes génétiques, problèmes phytosanitaires, qualité du liège en liaison avec la respective génomique sont adressées.PTDC/AGR-AAM/104364/200