A review on the utilization of fly ash

Phase change materials for thermal energy storage

Thermal energy storage (TES) systems using phase change material (PCM) have been recognized as one of the most advanced energy technologies in enhancing the energy efficiency and sustainability of buildings. Now the research is focus on suitable method to incorporate PCMs with building. There are several methods to use phase change materials (PCMs) in thermal energy storage (TES) for different applications. Microencapsulation is one of the well known and advanced technologies for better utilization of PCMs with building parts, such as, wall, roof and floor besides, within the building materials. Phase change materials based microencapsulation for latent heat thermal storage (LHTS) systems for building application offers a challenging option to be employed as effective thermal energy storage and a retrieval device. Since the particular interest in using microencapsulation PCMs for concrete and wall/wallboards, the specific research efforts on both subjects are reviewed separately. This paper presents an overview of the previous research work on microencapsulation technology for thermal energy storage incorporating the phase change materials (PCMs) in the building applications, along with few useful conclusive remarks concluded from the available literature.

Development of phase change materials based microencapsulated technology for buildings: a review

Microencapsulation of phase change materials (PCMs) is an effective way of enhancing their thermal conductivity and preventing possible interaction with the surrounding and leakage during the melting process, where there is no complete overview of the several methods and techniques for microencapsulation of different kinds of PCMs that leads to microcapsules with different morphology, structure, and thermal properties. In this paper, microencapsulation methods are perused and classified into three categories, i.e. physical, physic-chemical, and chemical methods. It summarizes the techniques used for microencapsulation of PCMs and hence provides a useful tool for the researchers working in this area. Among all the microencapsulation methods, the most common methods described in the literature for the production of microencapsulated phase change materials (MEPCMs) are interfacial polymerization, suspension polymerization, coacervation, emulsion polymerization, and spray drying.

A review of microencapsulation methods of phase change materials (PCMs) as a thermal energy storage (TES) medium

Various types of solid–liquid phase change materials (PCMs) have been reviewed for thermal energy storage applications. The review has shown that organic solid–liquid PCMs have much more advantages and capabilities than inorganic PCMs but do possess low thermal conductivity and density as well as being flammable. Inorganic PCMs possess higher heat storage capacities and conductivities, cheaper and readily available as well as being non-flammable, but do experience supercooling and phase segregation problems during phase change process. The review has also shown that eutectic PCMs have unique advantage since their melting points can be adjusted. In addition, they have relatively high thermal conductivity and density but they possess low latent and specific heat capacities. Encapsulation technologies and shell materials have also been examined and limitations established. The morphology of particles was identified as a key influencing factor on the thermal and chemical stability and the mechanical strength of encapsulated PCMs. In general, in-situ polymerization method appears to offer the best technological approach in terms of encapsulation efficiency and structural integrity of core material. There is however the need for the development of enhancement methods and standardization of testing procedures for microencapsulated PCMs.

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Review of solid–liquid phase change materials and their encapsulation technologies

Study on fired bricks with replacing clay by fly ash in high volume ratio

Microencapsulation of butyl stearate as a phase change material by interfacial polycondensation in a polyurea system

Dolomite Used as Raw Material to Produce MgO-based Expansive Agent

Background: As an anti-inflammatory prodrug, loxoprofen is metabolized into transloprofenol to treat diseases related to pain and inflammation. Although loxoprofen has fewer adverse effects than other NSAIDs, the safety of its usage during pregnancy remains unclear and needs to be considered. Fortunately, the toxicokinetics and tissue distribution study of transloxoprofen-alcohol in pregnant rats can resolve the problem. Objective: The purpose of this study is to establish a simple, sensitive, and effective LC-MS/MS analysis method for determining the concentration of trans-loxoprofen alcohol in plasma and tissues. Method: The analytic samples were precipitated by methanol in one step and separated using a reverse-phase Poroshell 120 EC-C18 column (4.6 mm×50 mm; 2.7 μm). And the mobile gradient phase at a flow rate of 0.6 mL/min was composed of acetonitrile and 0.1% formic acid in water. The quantitative detection was achieved by multiple-reaction monitoring mode with a positive electrospray ionization source, transitional ion pairs of m/z 265.9>184.8 for trans-loxoprofenalcohol, and 268.8>187.9 for rac-trans-loxoprofen-D3 alcohol (Internal standard). Result: A good linearity of calibration curves for plasma and tissues was observed in the concentration range from 5.0 to 5000 ng/mL, and the lower limit of quantification was detected at 5.0 ng/mL. The intra-day and inter-day precision in plasma and tissues were within 8.94% and 7.26%, respectively. The mean extraction recovery and matrix effects in plasma and tissues were in the range of 89.08~109.27% and 89.00~106.80%, respectively. Precision of stability in plasma and tissues was within 8.91% and 7.08%, respectively. Conclusion: Complying with the requirements of bioanalytical guidelines by validation, this method was successfully adopted to the toxicokinetics and tissue distribution study after intravenously administrated trans-loxoprofen-alcohol into pregnant SD rats. A R T I C L E H I S T O R Y Received: September 04, 2020 Revised: November 11, 2020 Accepted: November 18, 2020 DOI: 10.2174/157341291766620122210051 8

Determination of Trans-loxoprofen-alcohol Tromethamine in Pregnant SD Rats by a Validated LC-MS/MS Method：Application to a Toxicokinetics and Tissue Distribution Study

In order to improve dimensional stability of cementitious materials, synergistic effect of shrinkage reducing admixtures (mixture of glycol ethers and siloxane, SRA) and MgO-based expansive agent (MEA) burned at 850, 950, 1050 and 1200°C for 1 hour on the deformation of cement paste curried in water and sealed by polyethylene sheet at 20, 40, and 60°C was investigated in this paper. The results illustrated that combined use of MEA (850-950) and SRA could compensate the shrinkage of cement paste effectively, MEA also could make up for the shortage of SRA whose shrinkage-reducing ratio decreases at later age. Then hydration of MEA in the presence of SRA was examined by DSC/TG and gravimetry. The results indicated that the presence of SRA retarded the hydration of MEA because SRA decreased the polarity of solvent and adsorbed on the surface of MEA, but with prolonged curing, the hydration degree of MEA with or without SRA tended to be the same.

Xu Lingling

Papers

Study on fired bricks with replacing clay by fly ash in high volume ratio

Microencapsulation of butyl stearate as a phase change material by interfacial polycondensation in a polyurea system

Dolomite Used as Raw Material to Produce MgO-based Expansive Agent

Determination of Trans-loxoprofen-alcohol Tromethamine in Pregnant SD Rats by a Validated LC-MS/MS Method：Application to a Toxicokinetics and Tissue Distribution Study

Synergistic Effect of MgO-Based Expansive Agent and Shrinkage-Reducing Admixture on Compensating the Shrinkage of Cementitious Materials