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In order to study and analyze the causes of perforation failure in 3003 aluminum tubes， used in automobile air conditioning， the reasons for surface perforation defects in these tubes were investigated.This investigation involved macro-morphology analysis，chemical composition analysis， scanning electron microscope micro-morphology analysis and energy spectrum analysis.Results showed that nonmetallic inclusions on the surfaces of the 3003 aluminum tubes damaged the integrity and continuity of these surfaces.This issue prevented the formation of a dense oxide film at the inclusion sites.Under the combined influence of the strongly corrosive elements chlorine (Cl) and sulfur (S)， pitting and perforation failures occurred in the 3003 aluminum tubes.It was suggested that the addition of refining agents should be carefully controlled during the melting process of the 3003 alloy.Additionally， improvements in the filtering of inclusions in the aluminum liquid， as well as enhancements in the surface cleanliness and storage environment of the aluminum tubes， were recommended.These research findings could provide a certain reference for the manufacturing of 3003 aluminum tubes.

This paper investigates the thermo-mechanical volume change behavior of municipal solid waste (MSW) by conducting drained heating-cooling tests at constant stresses and isothermal consolidation tests using a temperature- controlled triaxial apparatus. The experimental results show that the compression and swelling indexes of MSW specimen were temperature independent, and the heating-induced volumetric contraction was partially reversible upon cooling. Different from conventional soils, the thermally induced reversible and irreversible volumetric strains of MSW were much larger and stress level dependent. Apart from the experimental study, an isotropic thermo-elastoplastic constitutive model was developed in the framework of existing modified Cam-clay model, which allows the prediction of thermally induced volume changes of MSW. An important feature in this model was the derivation of thermally induced plastic volumetric strain based on the concept of equivalent stress. The capability of the proposed model was validated against the experimental results and showed good predictions. This paper serves as the first attempt to study the thermo-mechanical volume change behavior of MSW, and has provided additional data for the serviceability evaluation of existing pipes as well as settlement and capacity estimation of MSW landfills at elevated temperatures. Key words: Municipal solid waste, temperature, volume change, constitutive model, thermo-mechanical, 1. Introduction Elevated temperatures (ETs) caused by biochemical degradation of organic wastes within municipal solid waste (MSW) landfills are widely observed and reported, which are usually featured with long periods [...]

ABSTRACT To appropriately simulate the long‐term mechanical behavior of municipal solid waste (MSW), a constitutive model coupling the effects of biodegradation and fibrous reinforcement was developed. In the proposed model, the compressive deformation due to biodegradation was regarded as being caused by an additional equivalent stress. Considering the effect of biodegradation, an evolution equation of the equivalent stress was proposed, and a plastic volumetric strain hardening law was developed. A fibrous reinforcement parameter was introduced, which was associated with the fiber content, stress state, and plastic shear strain of MSW. A plastic shear strain hardening law was developed to model the fibrous reinforcement. Based on the associated flow rule and two plastic strain hardening laws, the proposed model was established. The proposed model well simulated the hardening properties of MSW, as evidenced by the stress‒strain curves and the consistent, nonlinear increase in volumetric strain with axial strain. The differences in the shear strength and volumetric deformation due to the confining stress and fiber content were also well simulated by the model. Furthermore, the model predictions accurately reflected the findings of experiments conducted over a period of 10 years. Finally, parametric investigations were used to calibrate this proposed model, which can well characterize the long‐term MSW mechanical behavior. [ABSTRACT FROM AUTHOR]

In order to study the accuracy of commonly used desorption formulas in describing the gas desorption law of mixed particle coal samples, based on the adsorption and desorption experiments of mixed particle coal and gas under different adsorption pressures, Matlab software was used to fit the correlation coefficient and diffusion coefficient of each desorption formula in different adsorption pressures and time periods, and the fitting results were discussed and analyzed. The results show that the gas desorption amount and initial desorption velocity of mixed particle coal samples increase with the increase of adsorption pressure. The desorption law is suitable for Qin Yueping type, Winter type and Sun Chongxu type, but weak for Bolt type and Barrer type. When the adsorption pressure increases, the correlation coefficient of partial desorption formula also increases, and the diffusion coefficient of different formulas has a significant change trend. As the desorption time goes on, the correlation coefficient of partial desorption formula decreases.

A lithium-ion sieve (H1.6Mn1.6O4) with a porous nanofiber structure imitating the loofah skeleton was prepared in the currently reported work by performing electrospinning and high-temperature calcination. This prepared NFs@LIS-6:6 showed a controllable porous nanofiber structure and abundant Li+ adsorption sites. The separation coefficient for Mg2+ reached 421.68. Surprisingly, compared with particulate adsorbents, NFs@LIS-6:6 showed a 94.44% higher Li+ adsorption rate and 33.90% higher adsorption capacity, indicating an extraordinary potential for extracting Li+ from salt lake brine. [ABSTRACT FROM AUTHOR]

The stress-strain behavior of municipal solid waste (MSW) is important to predicate the deformation of MSW in landfills. Triaxial tests under K consolidation with different stress paths were carried out on MSW samples. Test results of the MSW are compared with that of clays in terms of stress-strain responses and coupled components. In triaxial extension tests, the stress-strain responses of MSW are similar to that of clays reported in literature. In triaxial compression tests, however, the stress-strain responses of the MSW are different from that of the clays, especially a progressively increasing upward curvature is observed at large strains without reaching a peak stress state on the compression stress paths of $$\Delta \sigma_{3}^{{\prime }}$$ ≥ 0. For the stress paths Δ q = 0 and Δ p′ < 0, although the volume of MSW specimen is expanded, the axial strain is increased, which is different from the behavior of the clays. Compared to the clays, the cross-coupling responses of the MSW are more pronounced. The most variations for shear and bulk modulus of MSW occur in q unloading range and p′ unloading range, respectively. The yield surface of MSW in p′ − q space is obtained and the fibrous reinforcement within specimens is confirmed in this study. Consequently, the stress-strain responses, shear and bulk modulus, and yielding characteristics of MSW are all closely related to the stress path. [ABSTRACT FROM AUTHOR]

One-dimensional silver nanomaterials, nanorods, and nanowires (NWs) were achieved by a solution-phase method. The geometry of the silver nanostructures was successfully tuned by adding polyvinylpyrrolidone (PVP) of different molecular weights. A possible mechanism, involving the suppression effect from PVP on the growth rates at different crystal facets, is used to explain the PVP-dependent morphology of the Ag nanowires achieved in this experiment. To evaluate its potential application in transparent electrodes, we also investigated the electrical conductance and optical transmittance after NWs were transferred to transparent polyethylene terephthalate substrates. Our findings indicated a possible and simple approach to control the morphology and then the functional properties of nanostructured silvers. [ABSTRACT FROM PUBLISHER]

The Semi-Flexible Water Retaining Pavement (SFWRP) has the capability to cool down the temperature of the road surface through its evaporation behavior, including absorbing and evaporating water; this is an efficient approach to relieve the heat island effect in a big city. The temperature feedback from different material surface were investigated in this paper in the same test condition, it has been proved that the SFWRP material can remarkably cool down the temperature of the road surface. The mechanism of the material evaporation behavior, including flux calculation formula of the water vapor inside the air void, were studied by inter-phase continuous function, in which the structural properties of the SFWRP material was taken into account. Furthermore, the function calculating the evaporation of the water vapor was then developed in this research through heat and mass transfer analogy. Besides, the calculating results can be captured by the self-coding program in Finite Element Modeling (FEM) for water evaporation simulation. Also, the results of laboratory tests were adopted to validate the calculating model. Finally, it has been proved that the mortar was recommended to be used in semi-flexible water retaining pavement to serve as material with permeable and water retaining property, and the semi-flexible water retaining pavement material is recommended to applied in the surface layer of the permeable pavement. [ABSTRACT FROM AUTHOR]