Search results for "substrate"
showing 10 items of 1018 documents
Preliminary data set to assess the performance of an outdoor membrane photobioreactor
2019
[EN] This data in brief (DIB) article is related to a Research article entitled 'Optimising an outdoor membrane photobioreactor for tertiary sewage treatment' [1]. Data related to the effect of substrate turbidity, the ammonium concentration at which the culture reaches nitrogen-deplete conditions and the microalgae growth rate under outdoor conditions is provided. Microalgae growth rates under different substrate turbidity were obtained to assess the reduction of the culture's light availability. Lab-scale experiments showed growth rates reductions of 22-44%. Respirometric tests were carried to know the limiting ammonium concentration in thismicroalgae-basedwastewater treatment system. Gro…
Determinants of Substrate Specificity in the NS3 Serine Proteinase of the Hepatitis C Virus
1997
AbstractProcessing of the nonstructural polyprotein of the hepatitis C virus (HCV) requires the serine-type proteinase located in the amino-terminal domain of NS3. To identify residues within NS3 determining substrate specificity, a mutation analysis was performed. Using sequence alignments and three-dimensional structure predictions, amino acids assumed to be important for specificity were replaced and the enzymes were tested in an intracellulartrans-processing assay for their effects on cleavage of an NS4B-5B substrate. For some of the substitutions at positions 133, 134, 135, 136, 138, 152, 155, 157, and 169, slightly reduced processing efficiencies were observed but in no case was the s…
Redox reaction between amino-(3,4-dihydroxyphenyl)methyl phosphonic acid and dopaquinone is responsible for the apparent inhibitory effect on tyrosin…
2002
Amino-(3,4-dihydroxyphenyl)methyl phosphonic acid, the phosphonic analog of 3,4-dihydroxyphenylglycine, had been previously reported as a potent inhibitor of tyrosinase. The mechanism of the apparent enzyme inhibition by this compound has now been established. Amino-(3,4-dihydroxyphenyl)methyl phosphonic acid turned out to be a substrate and was oxidized to o-quinone, which evolved to a final product identified as 3,4-dihydroxybenzaldehyde, the same as for 3,4-dihydroxyphenylglycine. Monohydroxylated compounds (amino-(3-hydroxyphenyl)methyl phosphonic acid and amino-(4-hydroxyphenyl)methyl phosphonic acid) were not oxidized, neither was 4-hydroxy-l-phenylglycine. However, the relatively hig…
Diastereoselective Synthesis of 2-Phenylselenenyl-1,3-anti-Diols and 2-Phenylselenenyl-1,3-anti-Azido-Alcohols via Hydroxy- and Azido-Selenenylation …
2005
A method to synthesize 2-phenylselenenyl-1,3-anti-diols and 2-phenyl- selenenyl-1,3-anti-azidoalcohols via hydroxy- or azido-selenenylation of trans-allylic alcohols is reported. Moreover, the first example of hydroxyl-selenenylation of an allylic azide is presented. Yields ranging from moderate to good and diastereomeric ratios up to 95:5 are achieved.
Unsaturated syn- and anti-1,2-Amino Alcohols by Cyclization of Allylic Bis-trichloroacetimidates. Stereoselectivity Dependence on Substrate Configura…
2014
Disubstituted allylic bis-imidates undergo Lewis acid catalyzed or spontaneous cyclization to oxazolines, which are precursors of unsaturated amino alcohols. Stereoselectivity of the cyclization is mainly determined by the substrate configuration. Highly selective cis-oxazoline formation is achieved starting from anti-E-bis-imidates while trans-oxazoline predominantly forms from anti-Z-bis-imidates. On the basis of DFT calculations, the stereoselectivity trends can be explained by the formation of the energetically most stable carbenium ion conformation, followed by the cyclization via most favorable bond rotations.
The Effect of Electronic Properties of Anodized and Hard Anodized Ti and Ti6Al4V on Their Reactivity in Simulated Body Fluid
2022
The electronic properties of barrier and porous layers on Ti and Ti6Al4V were studied. Barrier anodic oxides grown to 40 V on Ti and on Ti6Al4V are both n-type semiconductors with a band gap of 3.3 eV and 3.4 eV respectively, in agreement with the formation of amorphous TiO2. Anodizing to 200 V at 20 mA cm−2 in calcium acetate and β-glycerol phosphate disodium pentahydrate leads to the formation of Ca and P containing porous films with a photoelectrochemical behaviour dependent on the metallic substrate. A band gap of 3.2 eV and the flat band potential of −0.5 V vs Ag/AgCl were measured for the porous oxide on Ti, while optical transitions at 2.15 eV and a significantly more positive flat b…
Plasmonic effects of ultra-thin Mo films on hydrogenated amorphous Si photovoltaic cells
2012
We report on the improvement of short circuit current (JSC), fill factor (FF), and open circuit resistance (ROC) in hydrogenated amorphous silicon (a-Si:H) photovoltaic cells with a p-type/intrinsic/n-type structure, achieved by the addition of an ultra-thin molybdenum film between the p-type film and the transparent conductive oxide/glass substrate. For suitable conditions, improvements of ≈10% in average internal quantum efficiency and up to 5%–10% under standard illumination in JSC, FF, and ROC are observed. These are attributed to the excitation of surface plasmon polariton modes of the a-Si:H/Mo interface.
Effect of substrate improvement on optimising biogas yield from anaerobic digestion
2014
Masteroppgave i fornybar energi ENE 500 Universitetet i Agder 2014 The anaerobic digestion process involves the decomposition of the organic matter to yield biogas; gas that is mainly composed of methane and carbon dioxide with traces of some other gases. This process is used for different purposes including municipal waste treatment, wastewater treatment, fertilizer production, and farm wastes disposal as well as energy production. It is accomplished in three main stages; hydrolysis, acidogenesis and methanogenesis with each of the stages achieved by specific microorganisms that are active in limited ranges of operational and environmental conditions. These conditions are controlled to ach…
Influence of pH on the degradation kinetics of nitrophenol isomers in a heterogeneous photocatalytic system
1993
Abstract The kinetics of photocatalytic degradation of 2-, 3- and 4-nitrophenol in aqueousdispersions containing TiO2 (anatase) has been investigated at different initial values of pH and concentrations of substrate. A pseudo-first order kinetics with respect to the nitrophenol concentration was found to hold; an increase of the substrate concentration and the initial pH was detrimental on the degradation rate.
Photodegradation kinetics of aniline, 4-ethylaniline, and 4-chloroaniline in aqueous suspension of polycrystalline titanium dioxide
2000
The photodegradation process of aniline, 4-ethylaniline, and 4-chloroaniline in aqueous suspension of irradiated TiO2 (anatase) powder has been investigated. A batch photoreactor with immersed lamp irradiating in the near-UV region has been used for carrying out the reactivity experiments. For each substrate the influence of the initial concentration of organic compound and of pH on the degradation rate has been investigated. The main intermediates and the end products have been identified and determined, the total mass balance being satisfied. The kinetic modelling of the series of reactions occurring in the system has been satisfactorily carried out with a Langmuir-Hinshelwood rate law. T…