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Properties of polymer-metal hybrid structure printed by fed friction stir additive manufacturing (FFSAM) were evaluated. FFSAM is advanced solid-state additive manufacturing for the printing of macro-scale components for large stress-bearing situations. With the FFSAM, layer by layer printing of polymer and metal sheets convert to paste phase and join together as a uniform structure. With this process, during printing of hybrid structure, nanocomposite polymer is injected at the interface of base materials to fill voids and recover properties of the polymer matrix: polypropylene (PP) and stainless steel (SS) fabric selected as raw materials. During the printing process, Fe 2 O 3 nanoparticles fed into the interface of PP and steel sheets. The mechanical and metallurgical characterization of printed PP@SS@Fe 2 O 3 nanocomposite structure is evaluated. Macrostructure, tensile strength, hardness, and thermo-chemical properties of the printed structure were assessed and discussed. The result indicated that the In-situ feeding mechanism improves the physical and chemical properties of the printed structure. Reasonable properties achieved due to minimizing shrinkage gap in polymer side and improving sealing adhesion at interfaces of printed materials. [ABSTRACT FROM AUTHOR]

Abstract A mathematical model is used to predict adsorption isotherms from experimentally measured breakthrough curves. Using this approach, by performing only breakthrough experiments for a mixture of two (or more) components, one can obtain pure component adsorption isotherms up to the pressure of the experiment. As a case study, the adsorption of an equimolar mixture of CO 2 and CH 4 in zeolite ITQ-29 is investigated. Pure component linear adsorption isotherms for CO 2 and CH 4 are predicted by fitting the theoretical breakthrough curves to the experimental ones. Henry coefficients obtained from our approach are in excellent agreement with those measured experimentally. A similar procedure is applied to predict the complete Langmuir adsorption isotherm from breakthrough curves at high pressures. The resulting adsorption isotherms are in very good agreement with those measured experimentally. In our model for transient adsorption, mass transfer from the gas phase to the adsorbed phase is considered using the Linear Driving Force model and dispersion of the gas phase in the packed bed is taken into account. IAST is used to compute the equilibrium loadings for a mixture of gases. The influence of the dispersion coefficient and the effective mass transfer coefficient on the shape of breakthrough curves is investigated and discussed. Rough estimations of these values are sufficient to predict adsorption isotherms from breakthrough curves. Graphical abstract Image 1 Highlights • Prediction of adsorption isotherms from breakthrough curves. • Adsorption isotherms are estimated from breakthrough curves. • Effects of dispersion coefficient and mass transfer coefficient on the shape of the breakthrough curves are investigated. • This approach is applicable even for significantly eroded breakthrough curves. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Digital image correlation captures the crack length, tip remodeling, fatigue process zone, and strain. • Microstructurally-small cracking occurs in the HMA where aggregate-asphalt features drive crack propagation. • The cracking mechanisms observed in each specimen are unique; irrespective to temperature. Abstract The objective of this study is to demonstrate that digital image correlation can be employed to track crack propagation and produce more accurate measurements of the fatigue crack growth of hot mix asphalts. Indirect tensile, fracture, and fatigue crack growth (FCG) experiments are performed. Digital image correlation is shown to capture the crack propagation, crack tip remodeling, fatigue process zone, and strain distribution on the surface of the specimens. Microstructurally-small cracking is detected in the FCG data; where cracking is extremely sensitive to microstructural features. Failure analysis finds on the macroscale, the crack bypasses aggregates and propagates primarily through the mastic (bitumen and mineral filler). On the microscale, the temperature-dependent cohesive strength of the mastic governs FCG resistance. [ABSTRACT FROM AUTHOR]

In a world where capture and separation processes represent above 10% of global energy consumption, novel porous materials, such as Metal-Organic Frameworks (MOFs) used in adsorption-based processes are a promising alternative to dethrone the high-energy-demanding distillation. Shape and size tailor-made pores in combination with Lewis acidic sites can enhance the adsorbate-adsorbent interactions. Understanding the underlying mechanisms of adsorption is essential to designing and optimizing capture and separation processes. Herein, we analyze the adsorption behaviour of light hydrocarbons (methane, ethane, ethylene, propane, and propylene) in two synthesized copper-based MOFs, Cu-MOF-74 and URJC-1. The experimental and computational adsorption curves reveal a limited effect of the exposed metal centers on the olefins. The lower interaction Cu-olefin is also reflected in the calculated enthalpy of adsorption and binding geometries. Moreover, the diamond-shaped pores' deformation upon external stimuli is first reported in URJC-1. This phenomenon is highlighted as the key to understanding the adsorbent's responsive mechanisms and potential in future industrial applications. [Display omitted] [ABSTRACT FROM AUTHOR]

• Coal and SCG was co-combusted in a pilot-scale (30 kWth) fluidized bed combustor. • Coal-SCG blend had higher combustion efficiency than coal or coal-wheat straw blend. • Coal-SCG blend had lower tendency of agglomeration than coal-wheat straw blend. • SCG ash was shown to have fusibility temperatures only slightly lower than coal ash. • SCG could be co-combusted with coal without leading to higher NOx emissions. The co-combustion of coal and waste biomass is an advantageous option for combined waste biomass disposal and energy production. However, co-firing coal with waste biomass has to overcome various ash-related operational problems, for example, ash agglomeration and bed defluidisation in fluidised bed boilers. Using spent coffee grounds (SCG) for energy generation via co-combustion is much more sustainable and environmentally friendly than SCG disposal in landfills. The research done so far on the co-combustion of coal and SCG is quite scarce and almost non-existing. Further research is needed to understand how the properties of SCG affect the co-combustion of coal and SCG in existing coal-fired boilers. This study investigates the combustion of a bituminous coal blended with SCG in a pilot-scale (30kWth) bubbling fluidised bed (BFB) combustor focusing on CO and NOx emissions, combustion performance, and agglomeration tendency. The BFB combustion tests were conducted at 900 °C and atmospheric pressure using silica sand as the bed material. For comparison purposes, combustion tests of the same coal in pure and blended with wheat straw pellets at the same blending ratio were also performed. Further, ash fusibility studies were performed to elucidate the interactions between the coal ash and SCG ash, and the effect of ash compositions on the fusibility temperatures. Samples of the used bed material collected from the combustor and cyclone ash were characterised by SEM-EDS and XRF. The BFB combustion test results revealed that SCG could reduce the efficiency loss of coal combustion under co-combustion conditions. Despite the higher K 2 O content in SCG compared to wheat straw, a reduced agglomeration tendency was observed with the BFB combustion of the coal-SCG blends. The results from the characterisation of the used bed material, cyclone ash, and ash fusibility studies confirmed this finding, which was attributed to the formation of high melting temperatures Mg- and Ca-bearing compounds. [ABSTRACT FROM AUTHOR]

Abstract: Important research effort is currently being spent on reduction (if not complete removal) of lubricant consumption in machining operations. While scientific and industrial advances can be found in turning, milling and drilling technologies; advances in fluid reduction in grinding are still very limited. The main reason being abrasive processes generate large amounts of heat due to friction thus, the cooling/lubricant action of the fluid becomes critical. The Minimum Quantity of Lubricant-low temperature gas grinding technology (MCG, Minimum Coolant Grinding) can be considered a recent advance in this field. However, the economic and ecological application of the process requires minimization of both gas and oil consumption. The hypothesis put forward in this paper, is that the amount of lubricant required for the efficient industrial application of the MCG process can be largely reduced by using higher pour point lubricants. Since the explanation of the phenomena involved in the MCG process is that only a thin film of oil is responsible for effective tribo-action, then the amount of oil can be greatly reduced if effective freezing is achieved. The performance of two specifically-designed fluids for this purpose was studied. Experimental results show that even with very low quantities of oil and gas (3 mL/min and 0.2 kg/min) the MCG process produces better results than conventional cooling in terms of specific grinding energy and wheel wear. As far as residual stresses are concerned, results show that under industrial conditions these are similar in nature and magnitude to those generated using conventional cooling. [Copyright &y& Elsevier]

Abstract: In this paper we evaluate a distributed approach which uses numerical simulation and optimization techniques to automatically find remediation solutions to a hypothetical contaminated aquifer. The repeated execution of the numerical simulation model of the aquifer through the optimization cycles tends to be computationally expensive. To overcome this drawback, the numerical simulations are executed in parallel using a network of heterogeneous workstations. Performance metrics for heterogeneous environments are not trivial; a new way of calculating speedup and efficiency for Bag-of-Tasks (BoT) applications is proposed. The performance of the parallel approach is evaluated. [ABSTRACT FROM AUTHOR]

The use of an azine-linked covalent organic framework (ACOF-1) as filler in mixed-matrix membranes (MMMs) has been studied for the separation of CO 2 from N 2 . To better understand the mechanisms that govern separation in complex composites, MMMs were prepared with different loadings of ACOF-1 and three different polymers as continuous phase: low flux-mid selectivity Matrimid ® , mid flux-high selectivity Polyactive™ and high flux-low selectivity 6FDA:DAM. The homogeneous distribution of ACOF-1 together with the good adhesion between the ACOF-1 particles and the polymer matrices were confirmed by scanning electron microscopy. In mixed-gas CO 2 /N 2 separation a clear influence of the polymer used was observed on the performance of the composite membranes. While for Matrimid ® and 6FDA:DAM an overall enhancement of the polymer's separation properties could be achieved, in case of Polyactive™ penetration of the more flexible polymer into the COF porosity resulted in a decreased membrane permeability. The best improvement was obtained for Matrimid ® -based MMMs, for which a selectivity increase from 29 to 35, together with an enhancement in permeability from 9.5 to 17.7 Barrer for 16 wt% COF loading, was observed. Our results demonstrate that the combination of the filler-polymeric matrix pair chosen is crucial. For a given filler the polymer performance improvement strongly depends on the polymeric matrix selected, where a good match between the discontinuous and continuous phase, both in the terms of compatibility and gas separation properties, is necessary to optimize membrane performance. [ABSTRACT FROM AUTHOR]