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Refereed/Peer-reviewed The mechanisms leading to corrosion in stainless steel containments for thermal energy storage through phase change materials, such as carbonates and chlorides, are crucial for understanding the degradation of these steel alloys. A comprehensive study of this area will allow for down-selection of materials suitable for solar thermal energy storage (TES) operation at an elevated temperature range. Samples of stainless steel (SS) 316L were subjected to a cyclic heat environment of 550–750 °C in air and argon headspace environments, in the presence of a carbonate salt phase change material (PCM). A series of complementary microscopy, spectroscopy and diffractometry analytical techniques were applied to the corroded SS316L. Corrosion rate, interface formation and chemical products with respect to thermal cycling are presented with associated degradation mechanism explained and comparisons are made among different gas environments and varied immersion conditions. In the PCM under ambient air conditions, steel surfaces were mainly corroded by the penetration of oxidants from air, such as H2O or O2, along grain boundaries. SS316L samples demonstrated more severe degradation when exposed to air with a small fraction of PCM vapour present compared to when they were exposed to liquid or solid PCM. Cycling in Ar resulted in less corrosion in samples as opposed to when they were exposed to an air environment. In an Ar environment corrosion is driven via the formation of chromite, while the SS316L showed a less degradation when exposed to Ar with a small fraction of PCM vapour compared to when it was immersed in PCM. The mechanisms for degradation in air and in Ar are common in that the corrosion products of Cr and Ni dissolve in the PCM thus removing any layer that could protect against corrosion. The present study provides insight into corrosion of stainless-steel when exposed to carbonate salts, in air and inert gas environments, and contributes to down-selection of materials for solar thermal energy storage.

Off-gassing and self-heating are the major challenges when it comes to transportation and storage of wood pellets. The heat generated due to self-heating poses a fire risk while off-gassing of toxic gasses such as carbon monoxide (CO) and some volatile organic compounds (VOCs) is an environmental and human health risk. With the increase in production volumes of wood pellets which has subsequently increased the amounts of wood pellets in transportation and storage, there is need to find lasting solutions to off-gassing and self-heating of wood pellets. The objective of this study was to test the off-gassing abilities of Scots pine wood pellets produced from sawdust with varying amounts of extractives. The aim is to come up with raw material pre-treatment measures so as to produce wood pellets that are not liable to off-gassing. Six (6) types of sawdust raw materials namely; fresh pine sawdust (FPS), stored pine sawdust (SPS), sawdust plus pine rosin (PRS), sawdust plus linseed oil (LOS), sawdust plus tall oil (TOS) and acetone extracted sawdust (AES) were used to produce the pellets. The produced pellets were then subjected to off-gassing tests under controlled conditions using the ECOM J2KN analyser. The concentrations of carbon monoxide, carbon dioxide and methane increased with storage time but slowed down towards the end of the nine days test period. The formation of these gasses were largely dependent on the type of extractives present in the raw material and not the total extractive content. The formation of methane started later than the other gases and coincided with the time when residual oxygen was depleted.

Microcapsules consisting of paraffin wax cores with a melting point of approximately 42 °C and a melamine-formaldehyde resin shell were synthesized using in situ polymerization. These microcapsules have a uniform distribution with a spherical shape and an average diameter of approximately 15 μm. The thickness of the shell was approximately 1.5 μm. Shape-stabilized phase change materials (PCM) based on high-density polyethylene (HDPE) mixed with micro-encapsulated paraffin wax were prepared and investigated for application in thermal energy storage. The distribution of the capsules within the HDPE matrix was uniform without any tendency toward agglomeration. The microencapsulated paraffin wax acts as a high-latent-heat material, whereas the HDPE matrix ensures the compact shape, structural compactness and mechanical strength of the final PCM. The periodic temperature method was used to determine the thermal conductivity and thermal diffusivity of the phase change materials. A guarded hot plate unit was used to determine the latent heats of these phase-change materials. The thermal conductivity and diffusivity of the investigated PCMs decreased as the microcapsule content increased. In contrast, the latent, sensible and total heat of the PCMs increased with the paraffin content.

The results of investigation on the ageing of ceramic manganites La1-cSrcMn0.90Ni0.05Ge0.05O3+γ and La1-cSrcMn0.90Zn0.05Ti0.05O3+γ (c = 0.15, 0.17, 0.19) during long-term storage at normal conditions are presented. Unit cell volume of all manganites having rhombohedral structure decreased over time. The width of X-ray diffraction reflexes from (Ni,Ge)-compositions varied irregularly within the measurement error, and the width of reflexes from (Zn,Ti)-contained manganites decreased significantly. Magnetization of all samples increased in the end of storage period. Curie point of compositions with c > 0.17 exhibited some trend of increase. Ageing leaded to the lowering of “metal-semiconductor” transition temperature in (Ni,Ge)-substituted manganites. (Zn,Ti)-contained compositions showed only semiconductor behavior in investigated temperature range from 100 to 300 K, and the changes of their magnetic parameters were most considerable. The increase in magnetization and Curie point reached 7.5 % and 11 %, respectively. Possible mechanisms of ageing in considered materials are discussed in terms of oxidation processes, formation of microinhomogeneities and relaxation of internal stresses.

Porous activated carbon or nanostructured carbon materials have a promising future as hydrogen storage media. The hydrogen storage capacity of nanostructured carbon materials can be further enhanced by spillover of atomic hydrogen from a supported catalyst. In the present work, both of these factors have been put to test to study the hydrogen storage capacity of palladium (Pd) nanoparticles dispersed over the surface of functionalized hydrogen-exfoliated- graphene (Pd/f-HEG). The high-pressure hydrogen storage measurements of HEG and Pd/f-HEG show a hydrogen storage capacity of 0.5 and 1.76 wt % respectively at 25 �C and 2 MPa pressure. Functionalization of graphene facilitates uniform dispersion of Pd nanoparticles, which result in an increased hydrogen storage capacity of graphene by 69%. Heats of adsorption have been calculated for HEG and Pd/f-HEG that are consistent with the theoretical calculations from literature and provide an experimental evidence for the spillover effect. � 2011 American Chemical Society.

The effects of iron addition on the hydriding properties of Mg 6Pd were investigated. It was found that 15 min of co-milling Mg 6Pd and Fe in a high energy mill was sufficient to improve the sorption kinetics. Rietveld refinement of neutron powder diffraction patterns indicated that the presence of iron drastically modifies the system's micro-structure. A possible link between structure and hydrogen storage properties is discussed. © 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.

Minimization of total weight is the major criterion in the design of a solid state hydrogen storage device for mobile or portable applications. The design should also address the requirements such as storage capacity, charge/discharge rates, space constraints, coolant temperature and hydrogen supply pressure. To achieve this, one should be able to reliably predict the dynamic performance of the storage device. In this paper, a parametric study of hydrogen sorption in an air-cooled annular cylindrical hydrogen storage device with external fins is reported. LaNi 5 , which has excellent hydrogen storage properties is used as the hydriding material. The influence of different geometric parameters such as hydride bed thickness and fin height, and operational parameters such as hydrogen supply pressure and cooling air temperature are studied. Copyright , Manchester University Press.

Core-shell structured nanohybrids are currently of significant interest due to their synergetic properties and enhanced performances. However, the restriction of lattice mismatch remains a severe obstacle for heterogrowth of various core-shells with two distinct crystal structures. Herein, a controlled synthesis of lattice-mismatched core-shell TiO2@MoS2 nano-onion heterostructures is successfully developed, using unilamellar Ti0.87O2 nanosheets as the starting material and the subsequent epitaxial growth of MoS2 on TiO2. The formation of these core-shell nano-onions is attributed to an amorphous layer-induced heterogrowth mechanism. The number of MoS2 layers can be well tuned from few to over ten layers, enabling layer-dependent synergistic effects. The core-shell TiO2@MoS2 nano-onion heterostructures exhibit significantly enhanced energy storage performance as lithium-ion battery anodes. The approach has also been extended to other lattice-mismatched systems such as TiO2@MoSe2, thus suggesting a new strategy for the growth of well-designed lattice-mismatched core-shell structures. A controlled synthesis of lattice-mismatched core-shell TiO2@MoS2 nano-onion heterostructures is developed, using unilamellar Ti0.87O2 nanosheets as the starting material and the subsequent epitaxial growth of MoS2 on TiO2. The formation of these core-shell nano-onions is attributed to an amorphous layer-induced heterogrowth mechanism. The core-shell TiO2@MoS2 nano-onion heterostructures exhibit significantly enhanced energy storage performance as lithium-ion battery anodes. 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Scopus

cited By 3; International audience; Adsorption properties of gram-scale samples of different kind of arc discharge nanotubes were studied, namely: (A) raw collaret collected on the cathode, (B) raw soots collected on the lateral reactor wall, (C) thermally treated soot, and (D) thermally then chemically treated soot. The morphology, structure, and composition of these materials were characterized by SEM, TEM, TGA, and BET. In addition, hydrogen adsorption isotherms were recorded experimentally for A, B, and D samples over the pressure range of 0 to 55 bar at ambient temperature. Our experiments indicated a maximum - yet weak - hydrogen storage at room temperature of ∼0.13 H 2 wt% for the purified product (D). Copyright © 2007 American Scientific Publishers All rights reserved.

Background Magnesium alloys are recommended as a potential material for osteosynthesis. It is known that storage-induced property modifications can occur in materials like aluminum. Thus the aim of this study was to analyze the influence of storage durations of up to 48 weeks on the biomechanical, structural, and degradation properties of the degradable magnesium alloy LAE442. Methods Extruded implants (n = 104; Ø 2.5 mm × 25 mm) were investigated after storage periods of 0, 12, 24, and 48 weeks in three different sub-studies: (I) immediately after the respective storage duration and after an additional (II) 56 days of in vitro corrosion in simulated body fluid (SFB), and (III) 48 weeks in vivo corrosion in a rabbit model, respectively. In addition, the influence of a T5-heat treatment (206 °C for 15 h in an argon atmosphere) was tested (n = 26; 0 week of storage). Evaluation was performed by three-point bending, scanning electron microscopy, radiography, µ-computed tomography, evaluation of the mean grain size, and contrast analysis of precipitations (such as aluminum or lithium). Results The heat treatment induced a significant reduction in initial stability, and enhanced the corrosion resistance. In vivo experiments showed a good biocompatibility for all implants. During the storage of up to 48 weeks, no significant changes occurred in the implant properties. Conclusions LAE442 implants can be safely used after up to 48 weeks of storage.

Latent heat thermal storage systems (LHTS) utilize their latent heat capacity to dissipate high heat fluxes while maintaining quasi-isothermal conditions. Phase change materials (PCMs) absorb a large amount of energy during their phase transformation from solid to liquid, maintaining quasi-isothermal conditions. However, they are often beset with low thermal conductivities which necessitate the use of a thermal conductivity enhancer (TCE) as it is impossible to design a device that can completely avoid sensible heat in the premelting or postmelting phase. In this study, the heat transfer performance of LHTS with cross plate fins as a TCE is numerically investigated for different values of fin thicknesses and fin numbers along the length and breadth. A hybrid artificial neural network coupled genetic algorithm (ANN–GA) is then used to obtain the optimized dimensions for the composite heat sink with cross plate fins as TCE for a fixed volume and a specific heat flux input. The numerically optimized configuration is finally validated with in-house experiments.

Carbon materials should have specific centers for hydrogen adsorption/absorption. The Universal Force Field and Density Functional Theory have been used to find the role of heteroatom substitution in carbon nanotubes as an activator. The effect of various heteroatoms like nitrogen, phosphorus, sulphur and boron for hydrogen activation and their geometrical positions has been identified for easy hydrogenation. This will be one of the possible centers where hydrogen adsorption/absorption is initiated. � 2006 Elsevier Ltd. All rights reserved.

In this paper the authors attempt to modify the Brown Gibson Plant location model to consider the objective factors and applied analytic hierarchical process to consider the subjective factors in the decision process of selecting automatic storage and retrieval systems in place of traditional storage systems. ? Springer-Verlag London Limited 2005.

The goal of this study is to propose a cost-effective method for the optimization of the ex situ carbonation of basaltic rocks. The ball milling process was applied to a sample of olivine basalt from the Troodos ophiolite complex (Cyprus) for the first time, in order to fabricate novel nanomaterials for CO2 storage. The purpose was to accelerate the kinetics of rock–fluid reactions during the carbonation procedure. Various methodologies were used for the characterization of the starting rock material and the ball-milled samples. Preliminary results reveal that only a few hours of wet ball milling with ethanol as process control agent can induce significant changes to olivine basalt towards improvement of its performance for CO2 storage. Specifically, CO2 uptake measurements via the use of the temperature-programmed desorption (TPD) technique indicate that 4h of ball milling with 50wt.% ethanol can lead to an enhancement of the carbonation of olivine basalt by 295%. The experimental results strongly suggest that (i) olivine basalts have important CO2-storage capacity and are very promising lithotypes for ex situ carbonation, and (ii) the ball milling process provides hopes for its use at an industrial scale as a preparation technique for the safe and permanent ex situ storage of CO2. •The ball milling process was used to create novel nanomaterials for CO2 capture.•The experiments were carried out using a sample of olivine basalt.•Olivine basalt shows higher CO2 uptake compared to the reference forsterite.•The pore volume principally controls the extent of carbonation.•Ball milling results in an enhancement of the carbonation of olivine basalt by 295%. 273 220 229 220-229

`Electronic nose' applications have been increasing in number in recent years. The reliability of these applications is mainly based on the selectivity properties of the sensors composing the array and on the stability of their characteristics. In this paper an electronic nose based on metalloporphyrins-coated quartz microbalance sensors is described. Due to the nature of the chosen metals, the sensors are particularly suitable to classify environments in which compounds containing donor atoms, such as amines, alcohols and sulphides, play a key role. The aroma of fish during storage is one of these environments. The array has been applied both for classification and for identification of the degree of freshness of stored cod fish. Data on the recognition of storage days and continuous short time monitoring are reported and discussed. Results of the electronic nose response are displayed by a method that is based on the parametrization of the input temporal evolution and allows an adequate representation of the evolving chemical environment.

The use of powerful analytical methodologies for the evaluation of the performance of commercial oxygen storage materials based on oxygen transient isothermal isotopic exchange experiments is illustrated in this study. Ce x Zr1-x O2-based oxygen storage materials were investigated. The materials were characterized for their dynamic oxygen storage and release properties through the pulse injection technique allowing the measurement of the oxygen storage capacity (OSC), and for their surface and bulk oxygen mobility through transient isothermal 18O isotopic exchange experiments. Very high OSC values were obtained after calcination in air at Tcalc. = 700 or 850 °C. However, after thermal aging at 1000 or 1100 °C of the as prepared samples, a significant deterioration of their OSC was observed. This fact was found to correlate with the significant increase in the activation energy of surface oxygen mobility. On the contrary, smaller increase in the activation energy of bulk oxygen diffusion with increasing Tcalc. was observed. © 2009 Springer Science+Business Media, LLC. 52 13-20 2013 2018 Cited By :12