2Introduction: Numerous studies have been conducted on the development of modern insulators, including nano-insulators. However, a comprehensive study has yet to be performed to review and investigate the thermal properties of these insulators. Consequently, this study aimed to examine the effect of nanomaterials on thermal insulation function. Material and Methods: In this review, articles were searched for in English databases (PubMed, Web of Science, and ScienceDirect), Persian databases (Magiran, SID), and Google Scholar. The keywords used in the search were Nano Material, Nano insulation, Thermal insulation, Thermal Insulator Stability, and Thermal Conductivity in both English and Persian. Results: Of the 4068 studies identified through search databases, 15 were selected according to the entry criteria. Among the studies, the three types of silicone, composite, and aerogel insulation had the highest frequency (each 26.67%), and SiO2 nanoparticles were the most prevalent nanomaterial (26.67%). According to the studies, the type of nanomaterial used in insulation will improve its properties such as thermal resistance, mechanical strength, dielectric strength, tensile strength, elasticity, and hardness. Conclusion: The results of this study showed that using nanotechnology could be an effective step in improving the properties of insulation materials, the most important of which is increased thermal resistance. Moreover, nanotechnology insulators can prevent thermal energy loss, reduce costs, and provide safety and comfort.

The first solution to increase the efficiency of spacecraft is to decrease the weight of spacecraft which cause an increase in speed and flight range. Since the body of spacecraft tolerates a specific temperature range، the use of thermal protection systems which are designed to increase the weight of the structure in optimal conditions is essential. In this paper، thermal insulation with Heat sink as a body boundary condition is considered in order to lower body temperature. For this purpose، transient thermal conduction equations are written in the curvilinear coordinate system and it is developed for a variety of axially symmetric vehicles geometries. The ablative insulation material is graphite and the effects of pyrolysis layer are ignored. The equations are solved with using discrete finite difference method and governing equations are solved with using alternating direction implicit method (ADI). Then the impact of the Heatsink with different thickness on body temperature was investigated. The numerical results were compared with the exact solution results and they can see that their difference is less than 2% at all times. To reduce the body temperature، the concept of the Heatsink is used and the results show that the Heatsink decrease from 10% to 24% of the body temperature (depending on the thickness of the Heatsink).

The optimum thickness of the building envelope insulation materials depends on a large number of parameters. But the optimum thickness is calculated considering only economic arguments. In this paper, life-cycle assessment of the materials used in the building, and specifically the insulation ones, are included in the process to calculate the optimum insulation thickness from both environmental and energetic points of views. Within this frame, the large influence of the parameters associated with the manufacturing of the materials on the determination of the optimum thickness has been demonstrated: For all the studied cases, the insulation thickness depends in a large way on the unitary economic, energetic and environmental costs. The biggest differences in optimum thicknesses between two different insulation materials correspond to the highest differences in the unitary costs, for all the optimization points of views. The study also demonstrates that increasing values of the characteristic parameters of the manufacturing phase, which depend on the nature of the insulation materials, imply a decrease of the impact of the calculation settings, associated with the use phase of the building.

Traditional roofs can be effectively substituted by reinforced concrete roof slabs while gaining multiple advantages such as cyclonic resistance, possibility of future vertical extension and possibility of utilizing as an extra working space or a rooftop garden. Further, it adds a significant economic benefit from land regaining. However, the immediate space beneath the roof slab results in thermal discomfort and hence the inventions related to insulated roof slab systems have been increased recently. Although the expected thermal comfort could be achieved, most of the inventions use artificial thermal insulation materials such as polystyrene. This paper introduces a novel roof slab insulation system which uses the natural material of transversely cut bamboo layer as the thermal insulator. The proposed system minimizes the negative environmental impacts induced by the use of artificial insulation materials. The optimum insulation layer thickness is found to be 25 mm, which has acquired a 53% peak Heat gain reduction with a decrement factor of 0. 61 and a 3-h time lag.

Monitoring and evaluation of transformers are essential to prevent their insulation failure. In this paper, the use of 2-furan-carboxaldehyde (2-FAL) and methanol (MeOH) concentrations as the main products of paper insulation degradation, and insulation condition markers, has been studied. In order to study the degradation process and production of degradation products, the thermal aging process of the transformer insulation system was implemented in laboratory conditions. The results of laboratory studies show that in the early stages of degradation the amount of MeOH is significant compared to 2-FAL. Also, the estimation of the degree of polymerization (DP) in the early stages of degradation (DP>800) through MeOH concentration and with decreasing DP (DP <800) through 2-FAL concentration is closer to the real value. The results of studies performed on 35 distribution transformers confirm the production of significant amounts of MeOH in the early stages of degradation. Also, the estimated DP values for the studied transformers were obtained through 2-FAL and MeOH concentration. The results show that estimating the amount of DP through MeOH concentration is associated with a probability of error of about 9% compared to estimating DP through 2-FAL concentration.