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Photocatalytic degradation of methylene blue using glass fibers catalytic layer covered with red mud
Get PDFThe aim of this paper is to evaluate the degradation of methylene blue using progressive oxidation method. We have examined the effect of the intensity of the UV radiation and the influence of used catalytic layer on the methylene blue degradation efficiency. We have applied red mud catalyst on glass fibers Saertex layer in order to higher the degradation rate. We have found out that higher intensity of UV light of positively affects the efficiency of the degradation. Use of the catalyst layer formed by deposition of alternative catalyst (red mud) on glass fibers has increased the degradation efficiency of methylene blue
Dynamic Analysis of the Infinite Plate on Orthotropic Foundation Subjected to Moving Loads
Get PDFBased on the Kirchhoff thin plate theory and elastodynamics theory, the Kirchhoff small deformation infinite elastic thin plate is adopted to simulate the pavement, and the orthotropic elastic half space is used to simulate subgrade. The mechanical model and dynamic equations in the rectangular coordinate system are established for the infinite elastic plate on orthotropic foundation subjected to moving loads. The integral forms of plane strain dynamic responses are derived by means of Fourier transform and inverse Fourier transform. Numerical examples are conducted on condition that the harmonic vibrating strip load is applied on the plate surface. Studies are conducted to investigate the effect of the soil orthotropic parameters on dynamic response of subgrade and the plate. The results indicate that the anisotropy of the soil has a great influence on the dynamic response of subgrade and pavement interaction, and that dynamic response can be described more accurately by considering the orthogonal anisotropy of foundation
Study on the structure and properties of new metallocene high branched polyethylene
Get PDFThe branching composition, distribution and melting crystallization properties of very low density polyethylenes (VLDPE) with different carbon chain length were studied by means of nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC). The average sequence length (nE, nH, nB), relative monomer distribution (RMD) and monomer reactivity ratio (rE, rH, rB) were selected to analyze the polymerization characteristics. The crystallization characteristics of wafer thickness (L), relative branching degree (S) and crystallinity (Xc) were discussed by means of SSA thermal classification method. It has been found that the comonomer content and branching degree of VLDPE products with hexene (C6) as co monomers is lower than that of butene (C4) copolymer products; while the crystallinity and lamellar thickness is higher than that of C4 products
On the Behavior of Solid Oxide Fuel Cell Anode Materials in a Hydrogen Sulfide Containing Atmosphere
Get PDFThe effect of hydrogen sulfide content in a hydrogenous atmosphere on the structure, physical, and mechanical properties of solid oxide fuel cell (SOFC) anode materials has been studied. A series of specimens of porous nickel and YSZ-Ni cermet have been investigated. In order to obtain the corresponding YSZ-Ni cermet structure, specimens of the YSZ-NiO ceramics were singly reduced in a hydrogenous atmosphere (either Ar-5 vol% H2 mixture or hydrogen of 99.99 vol% H2 purity) for 4 h at 600°C under the pressure of 0.15 MPa. A part of the specimens of each series was then aged in "hydrogen sulfide in Ar-5 vol% H2 mixture" atmosphere for 4 h at 600°C. According to a test mode, the atmosphere contained 7 or 18 vol% H2S. Material microstructure and fracture surface morphology of the specimens as well as the physical and mechanical behaviors were investigated. It was revealed that the atmosphere containing up to 7 vol% H2S does not affect the strength and electrical conductivity of the YSZ-Ni cermet. Increased content of H2S (18 vol%) causes some changes in the YSZ-Ni cermet structure. A large number of completely reduced tiny nickel particles is formed. These nickel particles react with hydrogen sulfide. Sulfur is segregated on the boundaries between the zirconia and nickel phases and pores. Finally, multiple breaking of the zirconia-nickel bonds occurs that results in reduced strength of the cermet (by 39% as compared to as-received ceramics)
Effect of Preparation Technologies on Properties of Reactive Powder Concrete with Nano-zirconia
Get PDFReactive powder concrete filled with 3% content of nano-zirconia (NZ) are fabricated to investigate the effect of preparation technologies on the mechanical strength. The preparation technologies involve internal (NZ is added in RPC and replaced cement )/external mixing(NZ is added in RPC but not replaced cement), ultrasonic time, high mixing speed, saturated lime water/high temperature curing media(curing in water at 90℃). The influencing mechanisms of processing method are revealed through X-ray powder diffraction (XRD) and thermogravimetry (TG) analysis, scanning electron microscope observation. Experiment results showed that high mixing speed and high temperature curing media can improve the mechanical strength obviously. The compressive strength of NZ filled reactive powder concrete with high mixing speed increase 49.9%. The compressive strength, flexural strength and splitting strength of reactive powder concrete with NZ under high temperature curing media increase 35%, 15% and 17% respectively compared with control concrete
A closed-loop technology for metals recovery from e-waste: FENIX Project
Get PDFPrecious metals recovery from waste (in particular, electronic waste) has gained a high interest for the worldwide researchers. This is due to their large number of applications and also to achieve a conservation of primary raw materials. In other words, to apply the principle of circular economy. Therefore, using this approach, we are currently under progress with the development of a closed-loop process where the noble base metals coming from e-waste recycling are further used in the manufacturing of new products. This makes the objective of an European Project with the acronym FENIX which will last till the end of 2020. For the recovery of base and precious metals, innovative bio and hydrometallurgical process will be used. Then, the achieved products will be used for additive manufacturing of new electronic products and jewelries
Effect of Reaction and Regeneration on the Production of Pyridine Bases through Glycerol and Ammonia Route
Get PDFThe HZSM-22-At-acid and HZSM-5-At-acid catalysts were synthesized by alkaline-acid sequential treatment and the ZnO/HZSM-5-At-acid catalyst was synthesized by wet-impregnated method. Influence factors, including the types of reactors, impurities in glycerol and regeneration, were systematically investigated. The catalysts were characterized by XRD, TG, N2-physorption and NH3-TPD techniques. The catalytic evaluation showed that the total yield of pyridine bases in the series-connected two-stage reactors was significantly higher than that of the single reactor while the catalytic pair (HZSM-22-At-acid + ZnO/HZSM-5-At-acid) was employed in these reactors, respectively. It was found that the presence of methanol and sodium chloride in glycerol played a great negative effect on the total yield of pyridine bases. The coke was a key factor leading to the deactivation of catalyst. The catalytic activity was basically restored after the regeneration. The total yield of pyridine bases was increased up to 72% after the 6 th reaction, which was obviously higher than that of the similar reports. The characterization results demonstrated that the larger pore size and the declined concentration of acid site (particularly strong acid site) were main reasons for improving the catalytic activity
Study and modeling of the compressive and splitting tensile strengths of polypropylene fiber reinforced concrete containing recycled asphalt pavement
Get PDFIn a context of sustainable development and material recycling, the present study aims to study mechanical properties of a recycled asphalt pavement (RAP) concrete, reinforced with polypropylene fibers (PF). First, five formulations were designed with different RAP content with a maximum of 50% at a water cement ratio (W/C) of 0,50. Experimental results showed that the more RAP content increases in mix, the more mechanical strengths decrease, mainly due to the weak interfacial transition zone (ITZ) between the mortar and the recycled material. Reinforcement of PF at 0.1% and 1% volume fraction was realized on all mixes and the experimental results showed that the compressive strength is increased while the splitting strength is decreased. Then, an experimental linear relationship between the splitting tensile strength and the compressive strength is proposed. In the second part of the study, the mechanical strengths were modeled using a factorial plan 22, giving a quantification of the individual effect of both introduction of the RAP and the reinforcement and the combined effect, on response in terms of compressive strength and splitting tensile strength. Established model predicted the mechanical strength of a hardened concrete, whatever the RAP content and whatever the PF reinforcement content
Effect of Water Vapor Amount in a Hydrogenous Atmosphere on Structure and Properties of Nickel-Zirconia Anode Materials for Solid Oxide Fuel Cells
Get PDFNickel-zirconia anode ceramics of YSZ-NiO system for solid oxide fuel cells (SOFCs) has been investigated. A series of specimens were singly reduced in hydrogenous atmosphere (the Ar-5 vol%H2 mixture) at 600°C under the pressure of 0.15 MPa or subjected to reduction-oxidation (redox) cyclic treatment at 600°C. Influence of water vapor concentration in hydrogenous atmosphere on structure and properties of the materials was studied. Based on structural changes in the as-received material it was revealed that a small amount of water vapor in Ar-5 vol% H2 mixture (water vapor pressure below 0.03 MPa) accelerates a reduction of the nickel phase at 600°C with formation of nanopores on tiny Ni particles. A higher concentration of water vapor (the pressure above 0.03-0.05 MPa) causes a converse change in the reduction kinetics. For as-received material, such an amount of water vapor in the mixture is an obstacle for its reduction. For the material treated by redox cycling, better physical and mechanical properties were revealed after dwelling at 600°C in a water depleted gas mixture. Based on the SEM microscopy and the data on the conductivity and strength, the dual effect of water vapor on durability of a nickel-zirconia anode is discussed
The Effects of Antibacterial and Flame Resistance Finishing to the Properties of Cotton/Bamboo Pulp Interwoven Fabric
Get PDFIn order to better study the effects of antibacterial and flame resistance finishing to the properties of cotton/bamboo pulp interwoven fabric, a kind of cotton/bamboo pulp interwoven fabric was designed and woven. Fabric properties before and after antibacterial and flame resistance finishing like tensile strength at break, tearing strength, anti-bending stiffness, drapability coefficient, wrinkle recovery angle, air permeability, water vapor permeability, water absorption, dimensional stability to washing, vertical burn damaged length and bacterial inhibition rate etc. were tested. The results show that tensile strength at break, tearing strength, wrinkle recovery angle, air permeability, water vapor permeability, water absorption after antibacterial and flame resistance finishing are worse than those of before finishing. anti-bending stiffness, dynamic drapability coefficient, dimensional stability to washing, vertical burn damaged length, bacterial inhibition rate after antibacterial and flame resistance finishing are better than those of before finishing. Static basically remains the same. It is considered that fabric antibacterial and flame resistance property are better after finishing