Search results for "High activity"
showing 10 items of 13 documents
Organocatalytic Oxidation of Secondary Alcohols Using 1,2-Di(1-naphthyl)-1,2-ethanediamine (NEDA)
2014
Diamine, 1,2-di(1-naphthyl)-1,2-ethanediamine (NEDA), efficiently catalyzes the oxidation of alcohols by using TBHP as an oxidant. Notably, secondary benzyl alcohols are oxidized in almost quantitative yields, and the catalyst also displays high activity towards even hindered cycloaliphatic secondary alcohols. With enantiopure (R,R)-NEDA, oxidative kinetic resolution can be realized and depending on the alcohol ee up to 99 % are achieved.
Life-history genotype explains variation in migration activity in Atlantic salmon (Salmo salar)
2021
AbstractOne of the most important life-history continuums is the fast–slow axis, where “fast” individuals mature earlier than “slow” individuals. “Fast” individuals are predicted to be more active than “slow” individuals; high activity is required to maintain a fast life-history strategy. Recent meta-analyses revealed mixed evidence for such integration. Here, we test whether known life-history genotypes differ in activity expression by using Atlantic salmon (Salmo salar) as a model. In salmon, variation in Vgll3, a transcription co-factor, explains ∼40% of variation in maturation timing. We predicted that the allele related to early maturation (vgll3*E) would be associated with increased a…
Stabilized Naked Sub-nanometric Cu Clusters within a Polymeric Film Catalyze C-N, C-C, C-O, C-S, and C-P Bond-Forming Reactions
2015
[EN] Sub-nanometric Cu clusters formed by endogenous reduction of Cu salts and Cu nanoparticles are active and selective catalysts for C−N, C−C, C−O, C−S, and C−P bond-forming reactions. Sub-nanometric Cu clusters have also been generated within a polymeric film and stored with full stability for months. In this way, they are ready to be used on demand and maintain high activity (TONs up to 104 ) and selectivity for the above reactions. A potential mechanism for the formation of the sub-nanometric clusters and their electronic nature is presented.
Serum Malondialdehyde Correlates with Therapeutic Efficiency of High Activity Antiretroviral Therapies (HAART) in HIV-1 Infected Children
2002
Serum malondialdehyde (MDA) levels are increased in human immunodeficiency virus (HIV)-infected children, as it happens also in infected adult individuals. Introduction of high activity antiretroviral therapy (HAART) has promoted an intense decline in morbidity and mortality of these patients. Here we present data on the effect of HAART on serum MDA of HIV+ children and compare them with levels prior to HAART. MDA levels reflect, as other markers do, the HAART-induced clinical improvement and probably also the pro-oxidant/antioxidant side effects of the different drugs used. The results herein allow the proposal of including serum MDA levels as an additional parameter for the clinical manag…
Organometallic vanadium‐based heterogeneous catalysts for ethylene polymerization. Study of the deactivation process
1998
Slurry polymerizations of ethylene over vanadium catalysts (based on VCl4 and VOCl3) and their MgCl2(THF)2-supported equivalents were studied. Unsupported vanadium catalysts were found to be unstable while the vanadium active sites deposited on the MgCl2(THF)2 complex are stable. A sharply outlined correlation was found between the concentration of vanadium(III) and catalyst productivity. The high activity and stability of the vanadium catalyst when supported on the magnesium complex is attributed to the increase of resistance to reduction of active vanadium(III) to inactive vanadium(II) by an organoaluminium co-catalyst.
Monitoring pH and ORP in a SHARON reactor
2011
This paper analyses the valuable information provided by the on-line measurements of pH and oxidation reduction potential (ORP) in a continuous single high ammonia removal over nitrite (SHARON) reactor. A laboratory-scale SHARON reactor equipped with pH, ORP, electric conductivity and dissolved oxygen (DO) probes has been operated for more than one year. Nitrogen removal over nitrite has been achieved by adding methanol at the beginning of anoxic stages. Time evolution of pH and ORP along each cycle allows identifying the decrease in nitritation rate when ammonia is consumed during the aerobic phase and the end of the denitrification process during the anoxic phase. Therefore, monitoring pH…
Enhancing Performance of a Bis(arylimino)pyridine‐Iron Precatalyst for Ethylene Polymerization by Substitution with a 2,4‐Bis(4,4′‐dimethoxybenzhydry…
2021
A series of unsymmetrical 2-(2,4-bis(bis(4-methoxyphenyl)methyl)-6-MeC6H2N)-6-(1-(arylimino)ethyl)pyridine-iron halides has been synthesized and characterized. The molecular structure of two representative species was determined by the single-crystal X-ray diffraction. Activated with either MAO or MMAO, the precatalysts displayed high activity, reaching 2.19×107 g PE (mol Fe)−1 h−1 at 60 °C in ethylene polymerization. The microstructural analysis of the polymers obtained indicates highly linear polyethylene containing a vinyl chain end.
Spanish Photographic Meteor Network: An interdisciplinary crosslink
2001
This paper reports the birth of the Spanish Photographic Meteor Network (SPMN), a project that began their activities in 1997 through professional and amateur astronomers, coinciding with the high activity associated to several stream’s outbursts. One of the objectives of the network is to develop a continuous fireball monitoring in Spain and to obtain orbital and chemical information on meteoroids. Today the SPMN is a solid project under the auspices of three Universities (University Jaume I, University of Valencia and University of Barcelona) and one Space Institute (Catalonian Institute for Space Studies). The National Institute for Aerospace Research (INTA) and the Scientific Research C…
High activity mesoporous copper doped cerium oxide catalysts for the total oxidation of polyaromatic hydrocarbon pollutants
2012
The doping of mesoporous ceria with copper significantly enhances activity for naphthalene total oxidation, the enhanced performance is controlled by the increased concentration of surface oxygen defects.
Solvent free oxidation of primary alcohols and diols using thymine iron(III) catalyst.
2010
In this study, we developed an efficient and selective iron-based catalyst system for the synthesis of ketones from secondary alcohols and carboxylic acids from primary alcohol. In situ generated iron catalyst of thymine-1-acetate (THA) and FeCl(3) under solvent-free condition exhibits high activity. As an example, 1-octanol and 2-octanol were oxidized to 1-octanoic acid and 2-octanone with 89% and 98% yields respectively.