Search results for "reduction"
showing 10 items of 2058 documents
MWCNTs-Supported Pd(II) Complexes with High Catalytic Efficiency in Oxygen Reduction Reaction in Alkaline Media
2018
We report here the remarkable catalytic efficiency observed for two Pd(II) azamacrocyclic complexes supported on multiwalled carbon nanotubes (MWCNTs) toward oxygen reduction reactions. Beyond a main (90%) 4e
Exploring the potential of some yeast strains in the stereoselective synthesis of aldol reaction products and its reduced 1,3-dialcohol derivatives
2013
Abstract The behavior of two yeast strains has been studied under different conditions. Both microorganims catalyzed the aldol reaction between activated aldehydes and acetone when a large amount of the latter was present in the reaction medium producing, with moderate stereoselectivity, the aldol product with the R configuration. No reduction of any of the products present in the medium was detected. On the other hand, the carbonyl group of the racemic aldol was reduced to produce chiral 1,3-dialcohol derivatives when water was employed as the only solvent. In this case, the resolution of the racemic starting material was also possible with one of the biocatalysts, and the aldol was recove…
Hf27Si6P10, a novel metal-rich compound with P2 groups
2000
The new ternary metal rich compound Hf27Si6P10 has been synthesized by reduction of HfP with Hf and Si; Hf27Si6P10 crystallizes in a new structure type, a characteristic and unexpected feature of which is the presence of P2 groups; the structural results are interpreted with the aid of high-level band structure calculations.
Probing DNA conductivity with photoinduced electron transfer and scanning tunneling microscopy.
2012
Abstract The possibility that the stacked DNA bases can mediate vectorial electron transfer has been examined using two different approaches. Experiments on photoinduced electron transfer with intercalated donors and acceptors (either randomly bound or linked dyads of ruthenium complex and viologen) indicate that while DNA may be a better medium than acetonitrile for electron transfer over short distances (2-3-base pair, equivalent to 10-14Å centre-to-centre separation), it is a poor medium for transport over larger separations. Attempts to measure conductivity of individual DNA molecules using scanning tunneling microscopy to image mixed monolayers of mercaptohexanol (MCH) and 30-mer or 10…
Determination of metal inventory and current efficiency in commercial aluminum reduction cells
1971
A method for the determination of the metal inventory in commercial aluminum reduction cells, based on radioisotope dilution, has been developed, employing a198Au tracer. By taking a large number of samples from the cells, the current efficiency is evaluated from the slope of the cumulative metal inventory vs time data. The method allows a determination of the current efficiency over a period of 2 to 3 days with a relative precision of approximately 1 pct. The paper gives a thorough discussion of the sources of error inherent in the procedure suggested.
Combined theoretical and experimental analysis of processes determining cathode performance in solid oxide fuel cells
2013
Solid oxide fuel cells (SOFC) are under intensive investigation since the 1980's as these devices open the way for ecologically clean direct conversion of the chemical energy into electricity, avoiding the efficiency limitation by Carnot's cycle for thermochemical conversion. However, the practical development of SOFC faces a number of unresolved fundamental problems, in particular concerning the kinetics of the electrode reactions, especially oxygen reduction reaction. We review recent experimental and theoretical achievements in the current understanding of the cathode performance by exploring and comparing mostly three materials: (La,Sr)MnO3 (LSM), (La,Sr)(Co,Fe)O3 (LSCF) and (Ba,Sr)(Co,…
Tertiary cytoreduction in the setting of recurrent ovarian cancer (Review)
2013
Ovarian cancer is the most lethal gynecological malignancy, with aggressive surgical debulking and adjuvant chemotherapy as the main treatment modalities. Optimal debulking during the primary surgery is significantly correlated with prolonged survival. As surgical techniques and chemotherapeutic agents improve, more patients with prolonged survival may face secondary and tertiary recurrences. The role of surgical debulking in secondary cytoreduction (SC) is not clearly defined and is based on retrospective series. The treatment of patients with primary or secondary recurrences generally consists of second-line chemotherapy, but may be performed on medically fit patients in certain circumsta…
When and how to treat acute hepatitis C?
2003
Background: Appropriate treatment of acute hepatitis C is still a matter of controversy due to the lack of large controlled trials. Aim: To assess the effectiveness of interferon as treatment for acute hepatitis C by meta-analysis. Methods: MEDLINE search (1985-2002) was supplemented with manual searches of reference lists. Studies were included if they were controlled trials comparing interferon to no treatment and if they included patients with either post-transfusion or sporadic acute hepatitis C. Twelve trials were analyzed (414 patients). The outcome assessed was the sustained virological response (SVR) rate (undetectable hepatitis C virus RNA in serum at least 6 months after cessation…
Association between residential proximity to environmental pollution sources and childhood renal tumors
2016
FI=3.835 (año 2016), Q1 Background: Few risk factors for childhood renal tumors are well established. While a small fraction of cases might be attributable to susceptibility genes and congenital anomalies, the role of environmental factors needs to be assessed. Objectives: To explore the possible association between residential proximity to environmental pollution sources (industrial and urban areas, and agricultural crops) and childhood renal cancer, taking into account industrial groups and toxic substances released. Methods: We conducted a population-based case-control study of childhood renal cancer in Spain, including 213 incident cases gathered from the Spanish Registry of Childhood T…
Exergoeconomic analysis as support in decision-making for the design and operation of multiple chiller systems in air conditioning applications
2020
Abstract Multiple-chillers systems represent viable solutions for medium/large-scale air conditioning applications characterized by variable cooling demand. The energy efficiency of such systems is influenced by the number of chillers, the combination of cooling capacities, and the load-sharing among the units. Large efforts have been devoted to developing efficient operation strategies for these systems, but rules of thumb are usually adopted for selecting cooling capacities thus leaving room for energy and economic savings. In this paper, exergoeconomic analysis is proposed as a promising method to identify near-optimal design and operation strategies, due to the capability of exergoecono…