scholarly journals Hydrogen Photo-Production from Glycerol Using Nickel-Doped TiO2 Catalysts: Effect of Catalyst Pre-Treatment

Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3351 ◽  
Author(s):  
Jesús Hidalgo-Carrillo ◽  
Juan Martín-Gómez ◽  
Julia Morales ◽  
Juan Carlos Espejo ◽  
Francisco José Urbano ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Uv Light ◽  
Irradiation Time ◽  
Fold Increase ◽  
Synthetic Methods ◽  
Solar Irradiation ◽  
Catalyst Pretreatment ◽  
Metal Support ◽  
Pre Treatment ◽  
Nickel Species

In the present piece of research, hydrogen production via the photo-reforming of glycerol (a byproduct from biodiesel generation) is studied. Catalysts consisted of titania modified by Ni (0.5% by weight) obtained through deposition–precipitation or impregnation synthetic methods (labelled as Ni-0.5-DP and Ni-0.5-IMP, respectively). Reactions were performed both under UV and solar irradiation. Activity significantly improved in the presence of Ni, especially under solar irradiation. Moreover, pre-reduced solids exhibited higher catalytic activities than untreated solids, despite the “in-situ” reduction of nickel species and the elimination of surface chlorides under reaction conditions (as evidenced by XPS). It is possible that the catalyst pretreatment at 400 °C under hydrogen resulted in some strong metal–support interactions. In summary, the highest hydrogen production value (ca. 2600 micromole H2·g−1) was achieved with pre-reduced Ni-0.5-DP solid using UV light for an irradiation time of 6 h. This value represents a 15.7-fold increase as compared to Evonik P25.

Study on Surface Pre-Treatment of FeCrAl Metallic Substrate for Hydrogen Production Catalysts

2013 ◽  
Vol 813 ◽  
pp. 465-470
Author(s):  
Xiao Xiao Zhang ◽  
Kun Su ◽  
Fan Lin Zeng ◽  
Yu Wen Zhang ◽  
Qi Fei Zhang ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Supported Catalysts ◽  
Element Composition ◽  
Metallic Substrate ◽  
Air Atmosphere ◽  
Fecral Alloy ◽  
Film Adhesion ◽  
Metal Support ◽  
Active Coating ◽  
Pre Treatment

Metal supported catalysts in hydrogen production reactor has a very broad application prospect. However, the film adhesion of active coating with the metal support is the key problem which needed to be solved urgently. In this paper, FeCrAl alloy was chosen as the metallic substrate. The effects of oxidation temperature and time on the morphology, crystal phase and element composition of the metal surface were investigated by XRD, SEM and EDAX. The results show that after pre-treatment of FeCrAl Metallic Substrate,a dense transition layer of α-Al2O3 formed on the surface of the metallic support. Thus the oxidized α-Al2O3 layer and the γ-Al2O3 coating could combine together better. The optimum pre-treatment condition is at 950°C for 10h in air atmosphere.

Selective Inhibition of Thromboxane Synthetase with Dazoxiben - Basis of Its Inhibitory Effect on Platelet Adhesion

1983 ◽  
Vol 49 (02) ◽  
pp. 096-101 ◽  
Author(s):  
V C Menys ◽  
J A Davies
Keyword(s):  
Arachidonic Acid ◽  
Platelet Adhesion ◽  
Fold Increase ◽  
Selective Inhibition ◽  
Inhibitory Effect ◽  
Selective Inhibitor ◽  
Coated Glass ◽  
Thromboxane Synthetase ◽  
Pre Treatment

SummaryPlatelet adhesion to rabbit aortic subendothelium or collagen-coated glass was quantitated in a rotating probe device by uptake of radio-labelled platelets. Under conditions in which aspirin had no effect, dazoxiben, a selective inhibitor of thromboxane synthetase, reduced platelet adhesion to aortic subendothelium by about 40% but did not affect adhesion to collagen-coated glass. Pre-treatment of aortic segments with 15-HPETE, a selective inhibitor of PGI2-synthetase, abolished the inhibitory effect of dazoxiben on adhesion. Concentrations of 6-oxo-PGFlα in the perfusate were raised in the presence of dazoxiben alone, and following addition of thrombin (10 units/ml) there was a 2-3 fold increase in concentration. Perfusion of damaged aorta with platelets labelled with (14C)-arachidonic acid in the presence of thrombin and dazoxiben resulted in the appearance of (14C)-labelled-6-oxo-PGFiα. Inhibition of thromboxane synthetase limits platelet adhesion probably by promoting vascular synthesis of PGI2 from endoperoxides liberated from adherent platelets, which subsequently promotes detachment of cells from the surface.

scholarly journals Straightforward Synthesis of Mn3O4/ZnO/Eu2O3-Based Ternary Heterostructure Nano-Photocatalyst and Its Application for the Photodegradation of Methyl Orange and Methylene Blue Dyes

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4661
Author(s):  
Jayachamarajapura Pranesh Shubha ◽  
Haralahalli Shivappa Savitha ◽  
Syed Farooq Adil ◽  
Mujeeb Khan ◽  
Mohammad Rafe Hatshan ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Methyl Orange ◽  
Irradiation Time ◽  
Solar Irradiation ◽  
Anionic Dyes ◽  
One Pot ◽  
Sunlight Irradiation ◽  
Ft Ir ◽  
Degradation Activity ◽  
Ecological Applications

Zinc oxide-ternary heterostructure Mn3O4/ZnO/Eu2O3 nanocomposites were successfully prepared via waste curd as fuel by a facile one-pot combustion procedure. The fabricated heterostructures were characterized utilizing XRD, UV–Visible, FT-IR, FE-SEM, HRTEM and EDX analysis. The photocatalytic degradation efficacy of the synthesized ternary nanocomposite was evaluated utilizing model organic pollutants of methylene blue (MB) and methyl orange (MO) in water as examples of cationic dyes and anionic dyes, respectively, under natural solar irradiation. The effect of various experimental factors, viz. the effect of a light source, catalyst dosage, irradiation time, pH of dye solution and dye concentration on the photodegradation activity, was systematically studied. The ternary Mn3O4/ZnO/Eu2O3 photocatalyst exhibited excellent MB and MO degradation activity of 98% and 96%, respectively, at 150 min under natural sunlight irradiation. Experiments further conclude that the fabricated nanocomposite exhibits pH-dependent photocatalytic efficacy, and for best results, concentrations of dye and catalysts have to be maintained in a specific range. The prepared photocatalysts are exemplary and could be employed for wastewater handling and several ecological applications.

scholarly journals Solar Thermochemical Hydrogen Production in the USA

2021 ◽  
Vol 13 (14) ◽  
pp. 7804
Author(s):  
Christoph Falter ◽  
Andreas Sizmann
Keyword(s):  
Hydrogen Production ◽  
Large Scale ◽  
Low Cost ◽  
The United States ◽  
Solar Irradiation ◽  
Transport Sector ◽  
Fossil Energy ◽  
The Us ◽  
The Usa ◽  
Solar Thermochemical

Hydrogen produced from renewable energy has the potential to decarbonize parts of the transport sector and many other industries. For a sustainable replacement of fossil energy carriers, both the environmental and economic performance of its production are important. Here, the solar thermochemical hydrogen pathway is characterized with a techno-economic and life-cycle analysis. Assuming a further increase of conversion efficiency and a reduction of investment costs, it is found that hydrogen can be produced in the United States of America at costs of 2.1–3.2 EUR/kg (2.4–3.6 USD/kg) at specific greenhouse gas emissions of 1.4 kg CO2-eq/kg. A geographical potential analysis shows that a maximum of 8.4 × 1011 kg per year can be produced, which corresponds to about twelve times the current global and about 80 times the current US hydrogen production. The best locations are found in the Southwest of the US, which have a high solar irradiation and short distances to the sea, which is beneficial for access to desalinated water. Unlike for petrochemical products, the transport of hydrogen could potentially present an obstacle in terms of cost and emissions under unfavorable circumstances. Given a large-scale deployment, low-cost transport seems, however, feasible.

A sensitive and practical assay for thyroid-stimulating antibodies using FRTL-5 thyroid cells

1987 ◽  
Vol 115 (1) ◽  
pp. 30-36 ◽  
Author(s):  
Kanji Kasagi ◽  
Junji Konishi ◽  
Yasuhiro Iida ◽  
Yasutaka Tokuda ◽  
Keisuke Arai ◽  
...  
Keyword(s):  
Fold Increase ◽  
Graves Disease ◽  
Thyroid Cells ◽  
Thyroid Stimulating Antibodies ◽  
Silent Thyroiditis ◽  
Poorly Differentiated ◽  
Pre Treatment ◽  
Rat Thyroid ◽  
Serum Tsh ◽  
Bovine Tsh

Abstract. A sensitive, precise and practical assay for thyroid stimulating antibodies was developed in which poorly differentiated rat thyroid cells (FRTL-5) were exposed to crude immunoglobulin fractions precipitated from serum with 15% polyethylene glycol under hypotonic conditions. After the incubation at 37°C for 2 h, cAMP released into Hank's medium without NaCl was determined by radioimmunoassay. The removal of NaCl from the isotonic Hank's medium greatly enhanced cAMP production in response to both TSH and thyroid stimulating antibodies. The assay was sensitive enough to elicit an approximately 30-fold increase in cAMP at 10 mU/l bovine TSH. Thyroid stimulating activities measured using FRTL-5 cells significantly correlated with those measured using cultured porcine (r = 0.918, N = 72) or human (r = 0.830, N = 23) thyroid cells. Thyroid stimulating activities were detected in all of the 50 patients with hyperthyroid Graves' disease, the 14 patients with recurrent hyperthyroid Graves' disease, and the 25 patients with ophthalmic Graves' disease. Thyroid stimulating activity was also detected in some patients (9/24, 37.5%) with Hashimoto's thyroiditis whose serum TSH concentrations were higher than 30 mU/l. However, it was completely abolished by pre-treatment of the sera with anti-TSH antibodies. Although thyroid stimulating activities were detected in one of the patients with simple goitre (N = 10) and in one with thyroid cancer (N = 10), none of the patients with silent thyroiditis (N = 7), adenomatous goitre (N = 11), and thyroid adenoma (N = 9) were positive for thyroid stimulating antibodies.

Photodegradation of p-Nitrophenol Catalyzed by ZnO/MWCNTs Composite Catalyst in Water

2012 ◽  
Vol 455-456 ◽  
pp. 1339-1344 ◽  
Author(s):  
Zhe Qi Li ◽  
Jing Yu Liu
Keyword(s):  
Irradiation Time ◽  
Solar Irradiation ◽  
Composite Catalyst ◽  
Catalyst Loading ◽  
Optimal Conditions ◽  
Mass Ratio ◽  
Initial Substrate ◽  
Effects Of Ph ◽  
Potential Use ◽  
Initial Substrate Concentration

Photodegradation ofp-nitrophenol catalyzed by ZnO/MWCNTs composite in water was investigated. The effects of pH, irradiation time, catalyst loading, initial substrate concentration and MWCNTs content on the degradation were investigated. Experiment results revealed that the optimal conditions were ap-nitrophenol concentration of 60.0 mg/L at pH 5.0 with catalyst loading of 10.0 g/L under solar irradiation for the illumination of 180 min. The highest efficiency on photodegradation ofp-nitrophenol can be achieved with an optimal MWCNTs/ZnO mass ratio of 0.16%. Possible decomposing mechanisms were also discussed. The repeatability of photocatalytic activity was tested. The photocatalyst was used ten cycles with degradation efficiency still higher than 95%. The results of the study showed the feasible and potential use of ZnO/MWCNTs composite in degradation of toxic organic pollutants.

scholarly journals Photocatalytic Activity and Optical Properties of Blue Persistent Phosphors under UV and Solar Irradiation

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
C. R. García ◽  
L. A. Diaz-Torres ◽  
J. Oliva ◽  
M. T. Romero ◽  
P. Salas
Keyword(s):  
Photocatalytic Activity ◽  
Annealing Temperature ◽  
Uv Light ◽  
Solar Irradiation ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
X Ray ◽  
Water Cleaning ◽  
Different Temperatures ◽  
The Eu

Blue phosphorescent strontium aluminosilicate powders were prepared by combustion synthesis route and a postannealing treatments at different temperatures. X-ray diffraction analysis showed that phosphors are composed of two main hexagonal phases: SrAl2O4and Sr3Al32O51. The morphology of the phosphors changed from micrograins (1000°C) to a mixture of bars and hexagons (1200°C) and finally to only hexagons (1300°C) as the annealing temperature is increased. Photoluminescence spectra showed a strong blue-green phosphorescent emission centered atλem=455 nm, which is associated with4f65d1→4f6  (8S7/2)transition of the Eu2+. The sample annealed at 1200°C presents the highest luminance value (40 Cd/m2) with CIE coordinates (0.1589, 0.1972). Also, the photocatalytic degradation of methylene blue (MB) under UV light (at 365 nm) was monitored. Samples annealed at 1000°C and 1300°C presented the highest percentage of degradation (32% and 38.5%, resp.) after 360 min. In the case of photocatalytic activity under solar irradiation, the samples annealed at 1000°C, 1150°C, and 1200°C produced total degradation of MB after only 300 min. Hence, the results obtained with solar photocatalysis suggest that our powders could be useful for water cleaning in water treatment plants.

Intense Photoluminescence and Photoluminescence Enhancement of Silicon Nanocrystals by Ultraviolet Irradiation

2007 ◽  
Vol 31 ◽  
pp. 74-76 ◽  
Author(s):  
P.T. Huy ◽  
P.H. Duong
Keyword(s):  
Silicon Nanocrystals ◽  
Room Temperature ◽  
Laser Excitation ◽  
Uv Light ◽  
Irradiation Time ◽  
Excitation Wavelength ◽  
Nonradiative Recombination ◽  
Emission Yield ◽  
Recombination Centers ◽  
Pl Intensity

Photoluminescence (PL) from silicon nanocrystals deposited on top of silica-glass template and from silicon nanocrystals in nc_Si/SiO2 multilayer films were studied as a function of ultraviolet (UV) laser irradiation time in vacuum. Both the films exhibit intense visible PL at room temperature under laser excitation. It was found that upon prolong irradiation time using a He-Cd laser (325 nm) the PL intensity of the films was spectacularly enhanced. The process is reversible and does not happen with excitation wavelength longer than 400 nm. Upon introducing air into the measurement chamber, a rapid decrease of the PL intensity was recorded. This observation suggests that the UV light may lead to modification of nonradiative recombination centers in the films and thus improves the emission yield of silicon nanocrystals.

Photocatalytically Active Cotton Fabrics Produced with Anatase Synthesized Using a Low-Temperature Sol-Gel Process

2018 ◽  
Vol 762 ◽  
pp. 408-412
Author(s):  
Raivis Eglītis ◽  
Gundars Mežinskis
Keyword(s):  
Photocatalytic Activity ◽  
Uv Light ◽  
Sol Gel ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Sol Gel Process ◽  
Anatase Nanoparticles ◽  
Pre Treatment

In this work two different hydrosols were used to impregnate a commercially available cotton fabric with anatase nanoparticles to give it photocatalytic activity. To increase the activity, different pre-treatment methods were applied. The nanoparticle size was determined using dynamic light scattering and x-ray diffraction and the fabrics were examined using scanning electron microscopy. Photocatalytic activity was measured using the degradation of methyl-orange while irradiating the samples with UV light. The synthesis method allowed to produce anatase with an average particle size of 32 to 37 nm depending on the synthesis method used.

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