128 research outputs found
PRIMERA CONTRIBUCIÓN AL CONOCIMIENTO DE LOS BRACONZDAE (HYM., APOCRZTA, TEREBRANTZA) PARASITOIDES DE AGROMYZZDAE (DZPT., CYCLORRAPHA) EN LA PROVINCIA DE SALAMANCA (ESPAÑA)
Four species of Braconidae (Alysiinae) have been found in a suivey conducted in Salamanca dunng the year 1988. Two of them are new records for Spain. Two new host-parasitoide relationships have been settled.En los muestreos llevados a cabo durante el año 1988 en la provincia de Salamanca, se han hallado cuatro especies de Branconidae (Alysiinae), dos de las cuales constituyen nuevas citas para España. Se establecen dos nuevas combinaciones entre insectos hospedadores y parasitoides
FCC testing at bench scale: New units, new processes, new feeds
As the FCC process has evolved over decades, several laboratory scale equipment have appeared to maintain
a proper assessment of catalysts activity. Several laboratory equipments are available for simulating
the FCC process, from the well known fixed bed, MicroActivity Test to newer, fluid bed or transported
bed units. As well, a number of units have been created to simulate other parts of the process such as
regenerator or stripper, The increased pressure for treating non-conventional feeds, from reprocessing
gasoline to extra-heavy feeds or oils produced from biomass containing large amounts of heteroatoms,
increase the needs to have a laboratory test which is as close as possible to the process so that data
extraction from the laboratory test are simplified, thus less prone to errors or misunderstanding.Financial support by MICINN (Consolider-Ingenio 2010 MULTICAT) and MINECO (Project MAT2011-29020-0O2-02 and Subprogram for excellence Severo Ochoa, SEV 2012 0267) is gratefully acknowledged.Corma Canós, A.; Sauvanaud, LL. (2013). FCC testing at bench scale: New units, new processes, new feeds. Catalysis Today. 218-219:107-114. doi:10.1016/j.cattod.2013.03.038S107114218-21
Analysis of the Diversity of Megachilidae Bees on the Northern Subplateau of the Iberian Peninsula
In the western Mediterranean, 772 species of bees in the family Megachilidae have been reported. Special emphasis has been placed on the Iberian Peninsula, where to date 218 species are known. However, few intensive studies providing information about communities of Megachilidae have been carried out. Two earlier works cite 70 species; almost one third of those known on the Peninsula. With an aim of gaining insight into the structure of the communities of Megachilidae and the factors influencing them, an analysis was made of the alpha and beta diversity of different localities in the northern subplateau. Malaise traps (black and white) were used, and 559 specimens belonging to 55 species were identified of which most exhibited a nest-holder-type nesting habit. Abundance and richness were higher for white traps, although a considerable degree of complementarity was observed with the black traps. In the study zone, diversity can be considered medium-high with a phylogenetic diversity corresponding to stable populations. Regarding the composition of the Megachilidae communities, the influence of the landscape structure, of the microhabitat, and of the colour of the trap used to collect the specimens was detected. The following are recommended: (1) the use of both black and white traps, since they show high complementarity and offer different information about community structure, (2) homogenization of the samples in comparisons among communities, owing to the influence of the color of the trap, which masks the importance of ecological factors in community structuring, and (3) the collection of samples from at least two years previous, in view of the elevated “replacement” of species observed with species richness estimators
Ab Initio Screening Approach for the Discovery of Lignin Polymer Breaking Pathways
The directed depolymerization of lignin biopolymers is of utmost relevance for the valorization or commercialization of biomass fuels. We present a computational and theoretical screening approach to identify potential cleavage pathways and resulting fragments that are formed during depolymerization of lignin oligomers containing two to six monomers. We have developed a chemical discovery technique to identify the chemically relevant putative fragments in eight known polymeric linkage types of lignin. Obtaining these structures is a crucial precursor to the development of any further kinetic modeling. We have developed this approach by adapting steered molecular dynamics calculations under constant force and varying the points of applied force in the molecule to diversify the screening approach. Key observations include relationships between abundance and breaking frequency, the relative diversity of potential pathways for a given linkage, and the observation that readily cleaved bonds can destabilize adjacent bonds, causing subsequent automatic cleavage.Massachusetts Institute of Technology (Research Support Corporation, Reed Grant)United States. Dept. of Energy. Computational Science Graduate Fellowship Program (DOE-CSGF)Burroughs Wellcome Fund (Career Award at the Scientific Interface
Mnesic imbalance: a cognitive theory about autism spectrum disorders
Autism is characterized by impairments in social interaction, communicative capacity and behavioral flexibility. Some cognitive theories can be useful for finding a relationship between these irregularities and the biological mechanisms that may give rise to this disorder. Among such theories are mentalizing deficit, weak central coherence and executive dysfunction, but none of them has been able to explain all three diagnostic symptoms of autism. These cognitive disorders may be related among themselves by faulty learning, since several research studies have shown that the brains of autistic individuals have abnormalities in the cerebellum, which plays a role in procedural learning. In keeping with this view, one may postulate the possibility that declarative memory replaces faulty procedural memory in some of its functions, which implies making conscious efforts in order to perform actions that are normally automatic. This may disturb cognitive development, resulting in autism symptoms. Furthermore, this mnesic imbalance is probably involved in all autism spectrum disorders. In the present work, this theory is expounded, including preliminary supporting evidence
Comparison of Ni Based and Rh Based Catalyst Performance in the Oxidative Steam Reforming of Raw Bio-Oil
Selective Production of Aromatics by Crude Bio-oil Valorization with a Nickel-Modified HZSM-5 Zeolite Catalyst
Operating strategies for the oxidative steam reforming (OSR) of raw bio-oil in a continuous two-step system
On the dynamics and reversibility of the deactivation of a Rh/CeO2-ZrO2 catalyst in raw bio-oil steam reforming
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