Additional pathways for the ethanol electro-reforming knowledge: The role of the initial concentration on the product yields

Nanoemulsions were prepared by using emulsifiers with various sizes of hydrophilic and hydrophobic groups to determine the impact of interfacial characteristics on the stability of α-tocopherol incorporated into the nanoemulsions. The α-tocopherol concentration remaining after 3 weeks of storage at 25°C depended greatly on the type of oxidative stress, which indicated that the environment surrounding the oil droplets could determine the stability of α-tocopherol in nanoemulsions. α-Tocopherol was gradually degraded by radical-mediated oxidation over storage, and approximately 60% of its initial concentration remained after 3 weeks of storage. However, under acid- and iron-mediated oxidation, α-tocopherol concentration steeply decreases for the initial 3-day storage, but the degradation rate of α-tocopherol decreased after 3 days of storage and over 90% of the initial α-tocopherol remained after 3 weeks of storage. Interestingly, and contrary to our expectations, the thickness and/or density of the droplet interfacial membrane rarely affected the stability of α-tocopherol incorporated into nanoemulsions. Although it is difficult to generalize beyond α-tocopherol, we conclude that the properties of oil droplet surfaces had no influence on the storage stability of α-tocopherol encapsulated in the droplets.

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Inhibitory Effect of Hydrilla Verticillata on Planktonic Algae in Eutrophic Water

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.726-731.141 ◽

2013 ◽

Vol 726-731 ◽

pp. 141-146

Author(s):

Hong Jie Gao ◽

Yong Hui Song ◽

Jian Feng Peng ◽

Xiao Min Chen ◽

Mei Wang

Keyword(s):

Hydrilla Verticillata ◽

Inhibitory Effect ◽

High Biomass ◽

Initial Concentration ◽

Planktonic Algae ◽

Inhibition Ratio ◽

Eutrophic Water

The experiment adopted the method of cultivating Hydrilla verticillata and algae in coexistence systems to study the inhibitory effect of Hydrilla verticillata on planktonic algae in eutrophic water. The results showed that allelopathic and competition of nutrition inhibitory effect were both affect the inhibition of Hydrilla verticillata on planktonic algae at initial concentration of 105 cells·mL-1, and the highest inhibition ratio on was 79% at undernutrition condition; opposite, allelopathic inhibitory effect played a major role at nutritional sufficiency, the highest inhibition ratio was 39%. Hydrilla verticillata played a role of “promoting with low biomass while inhibiting with high biomass” on planktonic algae, the optimal biological dosage of Hydrilla verticillata on inhibiting planktonic algae at initial concentration of 105 cells·mL-1 was 12g·L-1. Hydrilla verticillata allproduced inhibitory effect on planktonic algae at different initial concentrations, and the greater the initial concentration of planktonic algae, the higher the inhibition ratio of Hydrilla verticillata on planktonic algae.

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Pyrolysis of Aryl Azides.X. Effects of Azide Concentration on Rate Constants and Product Yields

Australian Journal of Chemistry ◽

10.1071/ch9900997 ◽

1990 ◽

Vol 43 (6) ◽

pp. 997 ◽

Cited By ~ 18

Author(s):

LK Dyall ◽

PAS Smith

Keyword(s):

Free Radical ◽

Rate Constants ◽

Aryl Azides ◽

Radical Chain ◽

Initial Concentration ◽

Azo Compound ◽

Product Yields ◽

First Order ◽

Induced Decomposition ◽

Group Effects

First-order rate constants (k1) have been measured for pyrolysis of azidobenzenes in decalin solution, in the presence of a free-radical chain inhibitor to prevent any induced decomposition. The new values of k1 for the spontaneous unimolecular thermolysis are lower than previously reported ones, and require revision of published neighbouring group effects. Product yields ( azo compound and primary amine) vary with initial concentration of azide in ways which suggest the species responsible for induced decomposition is not triplet arylnitrene , but a solvent-derived free radical. There is no evidence for induced decomposition when nitrobenzene is the solvent. For aryl azides with no neighbouring group effects operating in their pyrolysis, the Arrhenius parameters Eact and ΔSactobey a precise linear relationship.

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Photodegradation of Methylene Green in the Presence of Polypropylene Microfiber Material

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.781.200 ◽

2018 ◽

Vol 781 ◽

pp. 200-205

Author(s):

Angelina Petrova ◽

Olga Tchaikovskaja ◽

Inna Plotnikova

Keyword(s):

Uv Radiation ◽

Uv Irradiation ◽

Photocatalytic Reactor ◽

Initial Concentration ◽

Photochemical Processes ◽

Methylene Green ◽

Photochemical Properties ◽

The Relationship ◽

Oxidizer Concentration

Degradation of toxicants in photocatalytic reactor is studied. To an array of data on the photochemical properties of Methylene Green (MG) when exposed to UV radiation in photoreactors was obtained. Based on the analysis of the results obtained, conclusions can be drawn about the relationship between the structure of pollutants, their initial concentration, oxidizer concentration, etc., with the efficiency of utilization, and schemes for photochemical processes was constructed. The role of polypropylene microfiber materials (PMM) in the degradation of MG under UV irradiation was studied.

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Reactivity of a Carene-Derived Hydroxynitrate in Mixed Organic/Aqueous Matrices: Applying Synthetic Chemistry to Product Identification and Mechanistic Implications

Atmosphere ◽

10.3390/atmos12121617 ◽

2021 ◽

Vol 12 (12) ◽

pp. 1617

Author(s):

Addison B. McAlister ◽

James I. Vesto ◽

Aaron Huang ◽

Kathryn A. Wright ◽

Emily J. McLaughlin Sta. Maria ◽

...

Keyword(s):

Water Concentration ◽

Organic Aerosol ◽

Organic Media ◽

Product Yields ◽

Major Class ◽

Product Identification ◽

Influence Of Water ◽

Condensed Phase Reactions ◽

Carbocation Rearrangement

β-hydroxynitrates (HN) are a major class of products formed during OH and NO3 initiated oxidation of terpenes. Their production contributes significantly to secondary organic aerosol (SOA) formation and NOx sequestration. However, studying the condensed phase reactions of this important class of molecules has been hindered by the lack of commercially available authentic standards. The goal of this work was to examine the influence of water concentration and solvent identity on product yields of a tertiary HN derived from 3-carene prepared in house. To assess the role of water on conversion chemistry, bulk-phase reactions were conducted in DMSO-d6, a non-nucleophilic solvent, with a gradient of water concentrations, and analyzed with 1H NMR. Product identifications were made by comparison with authentic standards prepared in house. Four major products were identified, including an unexpected diol produced from carbocation rearrangement, diol diastereomers, and trans-3-carene oxide, with varying yields as a function of water concentration. Product yields were also measured in two protic, nucleophilic solvents, MeOD-d4 and EtOD-d6. Finally, reactions with added chloride formed alkyl chloride products in yields approaching 30%. These results are among the first to highlight the complexities of nucleophilic reactions of hydroxynitrates in bulk, mixed aqueous/organic media and to identify new, unexpected products.

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THE ROLE OF MRI SCAN WITH CONTRAST AMPLIFICATION AT MULTI-PARAMETRIC MRI IN OPTIMIZATION OF X-RAY THERAPY OF RECURRENT CANCER OF PROSTATE

Medical Journal of the Russian Federation ◽

10.18821/0869-2106-2018-24-3-135-141 ◽

2018 ◽

Vol 24 (3) ◽

pp. 135-141

Author(s):

Filipp A. Kossov ◽

P. V Bulychkin ◽

B. P Olimov ◽

V. O Panov ◽

S. I Tkachev ◽

...

Keyword(s):

Prostate Cancer ◽

Mr Imaging ◽

Prostate Specific Antigen ◽

Intravenous Injection ◽

Specific Antigen ◽

Clinical Recurrence ◽

Initial Concentration ◽

X Ray ◽

Dynamic Mr

The purpose of study is to evaluate the role of dynamic contrast intensification as a constituent of multi-parametric MR-therapy in diagnostic of clinical recurrence of prostate cancer and optimization of salutary X-ray therapy. Materials and method. The sampling consisted of 89 patients with marker (prostate specific antigen) prostate cancer recurrence after radical prostate ectomy. The preliminary examination established no distant metastases. The multi-parametric MR-imaging of pelvis minor was applied both before salutary X-ray therapy and 6 months later after with purpose of applied treatment control. In 44 patients’ analysis was applied to data of dynamic MR-imaging with contrast intensification constituent to multi-parametric MR-imaging with intravenous injection of various MR-mediums (1M Gadobutrol, ½M Gadodiamid and ½M Gadoversetamid). The results. The model of multiple linear regression was applied to demonstrate that square of substrate of clinical recurrence statistically reliably correlates with level of marker of prostate specific antigen (R = 0,74; p < 0,0008) independently of type of injected various MR-mediums. The sensitivity of multi-parametric MR-imaging in detection of clinical recurrence of prostate cancer was evaluated by comparison with levels of prostate specific antigen and amounted to 92%, specificity - to 82%, accuracy - to 88%. The application of technique of hypo-fractionating of radiation dose on area of clinical recurrence of prostate cancer detected by multi-parametric MR-imaging demonstrated more progressive decreasing of marker of prostate specific antigen as compared with standard scheme of salutary X-ray therapy (according McNemarre criterion p < 0,03). The statistically reliable dependence (Mann-Whitney criterion p < 0,018) of alteration of signal in case of dynamic MR-imaging with contrast intensification after intravenous injection of various MR-mediums from square of substrate of clinical recurrence of prostate cancer and initial concentration of injected various MR-mediums between 1M Gadobutrol and ½M Gadodiamid and ½M Gadoversetamid. Conclusion. The multi-parametric MR-imaging has high sensitivity, specificity and accuracy in detection of substrate of clinical recurrence of prostate cancer. The application of in initial concentration of 1M (Gadobutrol) reliably increase validity of detection of local clinical relapse of prostate cancer especially in case of detection of substrate of recurrence of enough little and extra-little sizes. The application of multi-parametric MR-imaging using various MR-mediums marker in initial concentration of 1M (Gadobutrol) prior to course of salutary X-ray therapy enables to plan a supposed zone of X-ray impact with the purpose of more personalized brining of of high tumorocide dose of radiation at the area of clinical recurrence of prostate cancer needed for full resorption of recurrent tumor.

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Stability of wall bounded, shear flows of dense granular materials: the role of the Couette gap, the wall velocity and the initial concentration

Journal of Fluid Mechanics ◽

10.1017/jfm.2016.65 ◽

2016 ◽

Vol 791 ◽

pp. 384-413 ◽

Cited By ~ 4

Author(s):

C. Varsakelis ◽

M. V. Papalexandris

Keyword(s):

Granular Material ◽

Mechanical Model ◽

Particle Migration ◽

Shear Stresses ◽

Initial Concentration ◽

Wall Velocity ◽

Mode Stability ◽

The Stability ◽

Dynamics Simulations

In this paper, the stability of a plane, unidirectional Couette flow of a dense granular material is investigated via the means of a normal mode stability analysis. Our studies are based on a continuum mechanical model for the flows of interest coupled with the constitutive expressions for the normal and the shear stresses of the granular material induced by the ${\it\mu}(I)$-rheology. According to our analysis, both the Couette gap and the wall velocity play a destabilizing role in the flows of interest as opposed to the initial concentration that acts as stabilizer. For sufficiently high Couette gaps and wall velocities, unstable modes are recovered. The predicted instability manifests itself through shear-induced dilatancy that, in turn, engenders particle migration and the formation of bulbs, similar to the ones that have been acquired through molecular dynamics simulations.

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DT-diaphorase-catalysed reduction of 1,4-naphthoquinone derivatives and glutathionyl-quinone conjugates. Effect of substituents on autoxidation rates

Biochemical Journal ◽

10.1042/bj2570561 ◽

1989 ◽

Vol 257 (2) ◽

pp. 561-571 ◽

Cited By ~ 131

Author(s):

G D Buffinton ◽

K Öllinger ◽

A Brunmark ◽

E Cadenas

Keyword(s):

Electrochemical Detection ◽

Reduction Potential ◽

Reference Electrode ◽

Initial Concentration ◽

Quinone Reduction ◽

Half Wave ◽

H2o2 Formation ◽

Dt Diaphorase ◽

Wave Reduction

DT-diaphorase catalysed the reduction of 1,4-naphthoquinones with hydroxy, methyl, methoxy and glutathionyl substituents at the expense of reducing equivalents from NADPH. The initial rates of quinone reduction did not correlate with either the half-wave reduction potential (E1/2) value (determined by h.p.l.c. with electrochemical detection against an Ag/AgCl reference electrode) or the partition coefficient of the quinones. After their reduction by DT-diaphorase the 1,4-naphthoquinone derivatives autoxidized at distinct rates, the extent of which was influenced by the nature of the substituents. Thus for the 1,4-naphthoquinone series the following order of rate of autoxidation was found: 5-hydroxy-1,4-naphthoquinone greater than 3-glutathionyl-1,4-naphthoquinone greater than 5-hydroxy-3-glutathionyl-1,4-naphthoquinone greater than 1,4-naphthoquinone greater than 2-hydroxy-1,4-naphthoquinone. For the 2-methyl-1,4-naphthoquinone (menadione) series the following order was observed: 5-hydroxy-2-methyl-1,4-naphthoquinone greater than 3-glutathionyl-5-hydroxy-2-methyl-1,4-naphthoquinone greater than 3-glutathionyl-2-methyl-1,4-naphthoquinone greater than 2-methyl-1,4-naphthoquinone greater than 3-hydroxy-2-methyl-1,4-naphthoquinone. The autoxidized naphthohydroquinone derivatives were re-reduced by DT-diaphorase, thus closing a cycle of enzymic reduction in equilibrium autoxidation. This was expressed as an excess of NADPH oxidized over the initial concentration of quinone present as well as H2O2 formation. These findings demonstrate that glutathionyl conjugates of 1,4-naphthoquinone and 2-methyl-1,4-naphthoquinone and those of their respective 5-hydroxy derivatives are able to act as substrates for DT-diaphorase and that they also autoxidize at rates higher than those for the unsubstituted parent compounds. These results are discussed in terms of the cellular role of DT-diaphorase in the reduction of hydroxy- or glutathionyl-substituted naphthoquinones as well as the further conjugation of these hydroquinones with glucuronide or sulphate within the cellular milieu, thereby facilitating their disposal from the cells.

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Photocatalytic Degradation of Phenolics by N-Doped Mesoporous Titania under Solar Radiation

International Journal of Photoenergy ◽

10.1155/2012/780562 ◽

2012 ◽

Vol 2012 ◽

pp. 1-10 ◽

Cited By ~ 8

Author(s):

Priti A. Mangrulkar ◽

Sanjay P. Kamble ◽

Meenal M. Joshi ◽

Jyotsna S. Meshram ◽

Nitin K. Labhsetwar ◽

...

Keyword(s):

Photocatalytic Degradation ◽

Phenol Degradation ◽

Catalyst Loading ◽

Operating Parameters ◽

Mesoporous Titania ◽

Templating Method ◽

Initial Concentration ◽

Nitrogen Doped ◽

Coexisting Ions

In this study, nitrogen-doped mesoporous titania was synthesized by templating method using chitosan. This biopolymer chitosan plays the dual role of acting as a template (which imparts mesoporosity) and precursor for nitrogen. BET-SA, XRD, UV-DRS, SEM, and FTIR were used to characterize the photocatalyst. The doping of nitrogen into TiO2lattice and its state was substantiated and measured by XPS. The photocatalytic activity of the prepared N-doped mesoporous titania for phenol ando-chlorophenol degradation was investigated under solar and artificial radiation. The rate of photocatalytic degradation was observed to be higher foro-chlorophenol than that of phenol. The photodegradation ofo-chlorophenol was 98.62% and 72.2%, while in case of phenol, degradation to the tune of 69.25% and 30.58% was achieved in solar and artificial radiation. The effect of various operating parameters, namely, catalyst loading, pH, initial concentration and the effect of coexisting ions on the rate of photocatalytic degradation were studied in detail.

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