Assessing the impact of alumina nanoparticles in an anaerobic consortium: methanogenic and humus reducing activity

2011 ◽  
Vol 95 (5) ◽  
pp. 1323-1331 ◽  
Author(s):  
Luis H. Alvarez ◽  
Francisco J. Cervantes
Keyword(s):  
Alumina Nanoparticles ◽  
Anaerobic Consortium ◽  
Reducing Activity ◽  
The Impact

scholarly journals Experimental investigations on diesel engine using alumina nanoparticle fuel additive

2021 ◽  
Vol 13 (2) ◽  
pp. 168781402098840
Author(s):  
Mohammed S Gad ◽  
Sayed M Abdel Razek ◽  
PV Manu ◽  
Simon Jayaraj
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Alumina Nanoparticles ◽  
Experimental Investigations ◽  
Fuel Additive ◽  
Alumina Nanoparticle ◽  
Fuel Injectors ◽  
Performance And Emission ◽  
And Performance ◽  
The Impact

Experimental work was done to examine the impact of diesel fuel with alumina nanoparticles on combustion characteristics, emissions and performance of diesel engine. Alumina nanoparticles were mixed with crude diesel in various weight fractions of 20, 30, and 40 mg/L. The engine tests showed that nano alumina addition of 40 ppm to pure diesel led to thermal efficiency enhancement up to 5.5% related to the pure diesel fuel. The average specific fuel consumption decrease about neat diesel fuel was found to be 3.5%, 4.5%, and 5.5% at dosing levels of 20, 30, and 40 ppm, respectively at full load. Emissions of smoke, HC, CO, and NOX were found to get diminished by about 17%, 25%, 30%, and 33%, respectively with 40 ppm nano-additive about diesel operation. The smaller size of nanoparticles produce fuel stability enhancement and prevents the fuel atomization problems and the clogging in fuel injectors. The increase of alumina nanoparticle percentage in diesel fuel produced the increases in cylinder pressure, cylinder temperature, heat release rate but the decreases in ignition delay and combustion duration were shown. The concentration of 40 ppm alumina nanoparticle is recommended for achieving the optimum improvements in the engine’s combustion, performance and emission characteristics.

Development and characterization of structural adhesives for aerospace industry with alumina nanoparticles under shear and thermo-mechanical impact loads

2019 ◽  
Vol 234 (2) ◽  
pp. 490-507 ◽  
Author(s):  
UA Khashaba ◽  
Ramzi Othman ◽  
Ismael MR Najjar
Keyword(s):  
Contact Force ◽  
Bending Stiffness ◽  
Alumina Nanoparticles ◽  
Absorbed Energy ◽  
Impact Machine ◽  
Impact Properties ◽  
Weight Percentage ◽  
Mechanical Impact ◽  
Impact Bending ◽  
The Impact

The present work aims to improve the mechanical properties of Epocast 50-A1/946 epoxy via incorporation of alumina nanoparticles using an ultrasonic agitation method. The optimum weight percentage of alumina nanoparticles was determined based on the improvement in the shear and impact properties of the nanocomposites at room temperature and 50 ℃. Accordingly, neat epoxy panels and nanocomposite panels with 0.5, 1.0, 1.5, and 2.0 wt% alumina nanoparticles were fabricated. The shear and thermo-mechanical impact properties of the panels were measured using an instrumented drop-weight impact machine and an Iosipescu shear test fixture, respectively, according to ASTMs D5379 and D7136. The maximum improvement in shear strength and modulus was 10.9% and 8.1%, respectively, for the nanocomposites containing 1.0 and 1.5 wt% alumina nanoparticles. The predicted shear moduli of the nanocomposites agreed well with the measured values with a maximum error of 6.52%. The optimal performance of impact properties was achieved by incorporating 1.0 wt% of alumina nanoparticles. Namely, the maximum impact-bending stiffness, contact force, and absorbed energy were increased by 12.9%, 13.0%, and 23.4%, respectively. The test temperature of 50 ℃ was found to have a negative effect on the impact-bending stiffness and the maximum contact force. On the other hand, the absorbed energy was increased up to 12.1%.

Morphological and physical properties of kefiran-whey protein isolate bionanocomposite films reinforced with Al2O3 nanoparticles

2020 ◽  
Vol 26 (8) ◽  
pp. 666-675
Author(s):  
Zahra Moradi
Keyword(s):  
Mechanical Properties ◽  
Whey Protein ◽  
Water Solubility ◽  
Whey Protein Isolate ◽  
Protein Isolate ◽  
Alumina Nanoparticles ◽  
Vapor Permeability ◽  
Al2o3 Nanoparticles ◽  
Bionanocomposite Films ◽  
The Impact

Considering environmental pollution caused by the non-biodegradable polymers used in food packaging, developing and enhancing the properties of biodegradable films seem to be necessary. For this aim, in the present study, kefiran-whey protein isolate bionanocomposite films were prepared and the impact of different concentrations (1, 3 and 5% w/w) of Al2O3 (alumina) nanoparticles on their physical, morphological, thermal and mechanical properties was studied. Based on the obtained results, an increase in the nanoparticles content led to a significant decrease (p < 0.05) in the water vapor permeability, moisture absorption, moisture content, and water solubility. Scanning electron microscope images showed a homogeneous structure, confirming the good dispersion of alumina nanoparticles with smooth surface up to concentration of 3%. In addition, both thermal stability and mechanical properties of the films were improved by the increased concentrations of alumina. The results of X-ray diffraction indicated that the intensity of the crystalline peaks of film increased with the addition of Al2O3 to kefiran-whey protein isolate matrix. By considering all results, the concentration of 3% was proposed as the appropriate concentration of Al2O3 for the nano-reinforcement of kefiran-whey protein isolate bionanocomposites.

Impact of centrally applied biogenic amines upon the energy balance of fowl

1977 ◽  
Vol 232 (5) ◽  
pp. R137-R144
Author(s):  
P. E. Hillman ◽  
N. R. Scott ◽  
A. van Tienhoven
Keyword(s):  
Energy Balance ◽  
Body Temperature ◽  
Biogenic Amines ◽  
Thermal Response ◽  
Evaporative Heat Loss ◽  
Ambient Temperatures ◽  
Body Temperature Change ◽  
Intraventricular Injections ◽  
Reducing Activity ◽  
The Impact

The impact of intraventricular injections of 100 microng of the biogenic amines, norepinephrine or dopamine, upon the energy balance of white leghorn hens Gallus domesticus was examined. Both drugs reduce metabolic heat production (about 35% at 9 and 20 degrees C, and about 15% at 35 degrees C) by inhibiting shivering or by reducing activity or both. Also the drugs inhibit the opposing thermal response, evaporative heat loss (about 3% at 9 and 20 degrees C, and about 20% at 35 degrees C) by reducing respiration rate. The relative balance of inhibiting these opposing responses by the drugs results in hypothermia at 9 and 20 degrees C, and hyperthermia or no change in body temperature at 35 degrees C. Both drugs usually caused an initial vasodilation of the feet and comb at all temperatures tested but did not persist long enough to have much of an impact on body temperature. It was concluded that differing ambient temperatures do not alter the action of the biogenic amines upon the modes of physical thermoregulation in chickens even though the direction of body temperature change is reversed at different ambient temperatures.

scholarly journals Experimental and Computational Observations of Immunogenic Cobalt Porphyrin Lipid Bilayers: Nanodomain-Enhanced Antigen Association

Pharmaceutics ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 98
Author(s):  
Jasmin Federizon ◽  
Conrard Giresse Tetsassi Feugmo ◽  
Wei-Chiao Huang ◽  
Xuedan He ◽  
Kazutoyo Miura ◽  
...  
Keyword(s):  
Lipid Bilayers ◽  
Surface Display ◽  
Md Simulations ◽  
Nitrilotriacetic Acid ◽  
Aqueous Environment ◽  
Cobalt Porphyrin ◽  
Physical Mechanisms ◽  
Reducing Activity ◽  
The Impact ◽  
Transmission Blocking Vaccines

Cobalt porphyrin phospholipid (CoPoP) can incorporate within bilayers to enable non-covalent surface-display of antigens on liposomes by mixing with proteins bearing a polyhistidine tag (his-tag); however, the mechanisms for how this occurs are poorly understood. These were investigated using the his-tagged model antigen Pfs25, a protein antigen candidate for malaria transmission-blocking vaccines. Pfs25 was found to associate with the small molecule aquocobalamin, a form of vitamin B12 and a cobalt-containing corrin macrocycle, but without particle formation, enabling comparative assessment. Relative to CoPoP liposomes, binding and serum stability studies indicated a weaker association of Pfs25 to aquocobalamin or cobalt nitrilotriacetic acid (Co-NTA) liposomes, which have cobalt displayed in the aqueous phase on lipid headgroups. Antigen internalization by macrophages was enhanced with Pfs25 bound to CoPoP liposomes. Immunization in mice with Pfs25 bound to CoPoP liposomes elicited antibodies that recognized ookinetes and showed transmission-reducing activity. To explore the physical mechanisms involved, we employed molecular dynamics (MD) simulations of bilayers containing phospholipid, cholesterol, as well as either CoPoP or NTA-functionalized lipids. The results show that the CoPoP-containing bilayer creates nanodomains that allow access for a limited but sufficient amount of water molecules that could be replaced by his-tags due to their favorable free energy properties allowing for stabilization. The position of the metal center within the NTA liposomes was much more exposed to the aqueous environment, which could explain its limited capacity for stabilizing Pfs25. This study illustrates the impact of CoPoP-induced antigen particleization in enhancing vaccine efficacy, and provides molecular insights into the CoPoP bilayer properties that enable this.

Effect of an Anchor Geometry on the Hydrodynamic Characteristics of a Nanofluid in Agitated Tank

2021 ◽  
Vol 409 ◽  
pp. 179-193
Author(s):  
Abderrahim Mokhefi ◽  
Mohamed Bouanini ◽  
Mohammed Elmir ◽  
Pierre Spitéri
Keyword(s):  
Tilt Angle ◽  
Axial Flow ◽  
Alumina Nanoparticles ◽  
Hydrodynamic Characteristics ◽  
Hydrodynamic Behavior ◽  
Flat Bottom ◽  
Nanoparticles Concentration ◽  
Anchor Design ◽  
The Impact

In this paper, the flow of a shear thinning nanofluid in a mechanically stirred tank has been numerically analyzed. This tank is cylindrical with a flat bottom. It is filled with Al2O3 nanoparticles suspended in the base fluid and equipped with an anchor-type stirrer whose shape is tilted upwards at an angle α. The purpose of this research is to study the impact of the tilt angle (0≤α≤π/6) and the effect of the alumina nanoparticles concentration (0≤φ≤0.1) on the hydrodynamic behavior and energy consumption. In the new anchor design (α>0), the fluid volume that is swept during the rotation of the anchor is the same as that in the case of a standard anchor (α=0). The laminar flow of the nanofluid is governed by the continuity and momentum equations taking into account the physical properties of the nanofluid introduced through correlations cited in the literature. The results obtained have shown that the tilt angle significantly contributes to the reduction of the power number, and leads to a decrease in the intensity of the tangential flow at the level of the extreme transverse planes of the tank. However, this reduction in intensity is compensated by increasing the axial flow. The use of nanoparticles in this work aims to show the role of the new design of anchor in creating a vortex at the bottom of the tank and to avoid of particles sedimentation.

Decolorization and biogas production by an anaerobic consortium: effect of different azo dyes and quinoid redox mediators

2015 ◽  
Vol 72 (5) ◽  
pp. 794-801 ◽  
Author(s):  
L. H. Alvarez ◽  
R. Valdez-Espinoza ◽  
R. B. García-Reyes ◽  
D. Olivo-Alanis ◽  
M. T. Garza-González ◽  
...  
Keyword(s):  
Azo Dyes ◽  
Biogas Production ◽  
Inhibitory Effect ◽  
Redox Mediators ◽  
Direct Blue ◽  
Anaerobic Consortium ◽  
The Impact ◽  
Direct Blue 71

The inhibitory effect of azo dyes and quinoid compounds on an anaerobic consortium was evaluated during a decolorization process and biogas production. In addition, the impact of quinoid compounds such as lawsone (LAW) and anthraquinone-2,6-disulfonate (AQDS) on the rate of decolorization of Direct Blue 71 (DB71) was assessed. The anaerobic consortium was not completely inhibited under all tested dye concentrations (0.1–2 mmol l−1), evidenced by an active decolorization process and biogas production. The presence of quinoid compounds at different concentrations (4, 8, and 12 mmol l−1) also inhibited biogas production compared to the control incubated without the quinoid compounds. In summary, the anaerobic consortium was affected to a greater extent by increasing the quantity of azo dyes or quinoid compounds. Nevertheless, at a lower concentration (1 mmol l−1) of quinoid compounds, the anaerobic consortium effectively decolorized 2 mmol l−1 of DB71, increasing up to 5.2- and 20.4-fold the rate of decolorization with AQDS and LAW, respectively, compared to the control lacking quinoid compounds.

The Impact of Ru Contamination of a Pt∕C Electrocatalyst on Its Oxygen-Reducing Activity

2007 ◽  
Vol 10 (9) ◽  
pp. B150 ◽  
Author(s):  
Lajos Gancs ◽  
Brian Nicholas Hult ◽  
Nazih Hakim ◽  
Sanjeev Mukerjee
Keyword(s):  
Reducing Activity ◽  
The Impact

scholarly journals Characterization of an M-Cluster-Substituted Nitrogenase VFe Protein

mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Johannes G. Rebelein ◽  
Chi Chung Lee ◽  
Megan Newcomb ◽  
Yilin Hu ◽  
Markus W. Ribbe
Keyword(s):  
Fine Tuning ◽  
Ambient Conditions ◽  
Protein Scaffold ◽  
Reducing Activity ◽  
Co Reduction ◽  
The Impact ◽  
Protein Environment

ABSTRACTThe Mo- and V-nitrogenases are two homologous members of the nitrogenase family that are distinguished mainly by the presence of different heterometals (Mo or V) at their respective cofactor sites (M- or V-cluster). However, the V-nitrogenase is ~600-fold more active than its Mo counterpart in reducing CO to hydrocarbons at ambient conditions. Here, we expressed an M-cluster-containing, hybrid V-nitrogenase inAzotobacter vinelandiiand compared it to its native, V-cluster-containing counterpart in order to assess the impact of protein scaffold and cofactor species on the differential reactivities of Mo- and V-nitrogenases toward CO. Housed in the VFe protein component of V-nitrogenase, the M-cluster displayed electron paramagnetic resonance (EPR) features similar to those of the V-cluster and demonstrated an ~100-fold increase in hydrocarbon formation activity from CO reduction, suggesting a significant impact of protein environment on the overall CO-reducing activity of nitrogenase. On the other hand, the M-cluster was still ~6-fold less active than the V-cluster in the same protein scaffold, and it retained its inability to form detectable amounts of methane from CO reduction, illustrating a fine-tuning effect of the cofactor properties on this nitrogenase-catalyzed reaction. Together, these results provided important insights into the two major determinants for the enzymatic activity of CO reduction while establishing a useful framework for further elucidation of the essential catalytic elements for the CO reactivity of nitrogenase.IMPORTANCEThis is the first report on thein vivogeneration andin vitrocharacterization of an M-cluster-containing V-nitrogenase hybrid. The “normalization” of the protein scaffold to that of the V-nitrogenase permits a direct comparison between the cofactor species of the Mo- and V-nitrogenases (M- and V-clusters) in CO reduction, whereas the discrepancy between the protein scaffolds of the Mo- and V-nitrogenases (MoFe and VFe proteins) housing the same cofactor (M-cluster) allows for an effective assessment of the impact of the protein environment on the CO reactivity of nitrogenase. The results of this study provide a first look into the “weighted” contributions of protein environment and cofactor properties to the overall activity of CO reduction; more importantly, they establish a useful platform for further investigation of the structural elements attributing to the CO-reducing activity of nitrogenase.

Sign in / Sign up

Export Citation Format

Share Document