As energy use in the building sector is increasing worldwide, building materials with characteristics that save energy are becoming increasingly important; in addition, there is an emerging need for high-performance insulation materials with low thermal conductivity. However, thermal insulation should consider thermal conductivity, which is the main performance parameter, in addition to the water adsorption rate, acidity, and deformation and expansion due to drying conditions. This study evaluated the main performance of 21 insulation materials used at construction sites to objectively and clearly evaluate their overall performance, including their thermal conductivity. Thermal conductivity was measured by the heat flow meter method according to ASTM C518 and ISO 8301 standards; it was also evaluated according to the drying conditions. The water absorption rate was evaluated by ISO 2896 to ensure the sustainability and long-term thermal conductivity performance of the material. Acidity was evaluated with ASTM E861 to reduce the environmental load of the buildings and soil. The results of this study reviewed an appropriate method to measure the main performance according to the type of insulation.

Incessant release of a large spectrum of agro-industrial pollutants into environmental matrices remains a serious concern due to their potential health risks to humans and aquatic animals. Existing remediation techniques are unable to remove these pollutants, necessitating the development of novel treatment approaches. Due to its unique structure, physicochemical properties, and broad application potential, graphene has attracted a lot of attention as a new type of two-dimensional nanostructure. Given its chemical stability, large surface area, electron mobility, superior thermal conductivity, and two-dimensional structure, tremendous research has been conducted on graphene and its derived composites for environmental remediation and pollution mitigation. Various methods for graphene functionalization have facilitated the development of different graphene derivatives such as graphene oxide (GO), functional reduced graphene oxide (frGO), and reduced graphene oxide (rGO) with novel attributes for multiple applications. This review provides a comprehensive read on the recent progress of multifunctional graphene-based nanocomposites and nanohybrids as a promising way of removing emerging contaminants from aqueous environments. First, a succinct overview of the fundamental structure, fabrication techniques, and features of graphene-based composites is presented. Following that, graphene and GO functionalization, i.e., covalent bonding, non-covalent, and elemental doping, are discussed. Finally, the environmental potentials of a plethora of graphene-based hybrid nanocomposites for the abatement of organic and inorganic contaminants are thoroughly covered.

A novel platform and procedure were developed to characterize the ignitability of Alaska North Slope (ANS) crude oil and its water-in-oil products with water content up to 60% at low temperatures (−20–0°C). Time to ignition, critical heat flux, in-depth temperature profiles were investigated. It was observed that a cold boundary and consequent low oil temperature increased the thermal inertia of the oil/mixture and consequently the time to sustained ignition also increased. As the water content in the ANS water-in-oil mixture increased, the critical heat flux for ignition was found to increase. This is mainly because of an increase in the thermal conductivity of the mixture with the addition of saltwater. The results of the study can be used towards design of ignition strategies and technologies for in situ burning of oil spills in cold climates such as the Arctic.

This research aimed to quantify the effects of biochar derived from corn straw on soil thermal conductivity, capacity, and diffusivity. Firstly, the amount of biochar application (w/w) added to light sierozem soil was 0% to 5%, and the mixtures were packed into soil columns at a consistent bulk density (1.20 g.cm-3). Secondly, soil columns with a consistent biochar addition rate (5%) were packed to different bulk densities of 1.30, 1.25, 1.20, 1.15, and 1.10 g.cm-3. Soil thermal characteristics were measured under the control of soil moisture content from 0% to 40%. Under consistent bulk-density conditions, biochar could significantly reduce soil thermal conductivity and diffusivity. Still, there wasn’t a significant influence on soil heat capacity in most soil moisture content levels. With the decrease of soil bulk density, soil thermal conductivity, capacity, and diffusion coefficient reduced significantly. As soil water content increased, all the indexes of thermal properties largely improved, and the effects were much more significant than those of biochar amendment and bulk density change on soil thermal performances. This research could supply an implication to evaluate the influence of biochar amendment on soil thermal performances.

Geothermal energy is one type of renewable source of energy that can be used as shallow geothermal system for the use of cooling and heating of residential and commercial buildings. In this paper, an intense review is carried out on geothermal heating and cooling for air conditioning with a focus on Earth-Air Heat Exchanger (EAHE) and Ground Source Heat Pump (GSHP) systems. The study is carried out to understand the factors which have a significant effect on the performance of the EAHE and GSHP systems. This paper also focuses on the hybrid work of geothermal heating and cooling system with other forms of energy and provides benefits for designing efficient GSHP and EAHE systems. This study indicates that the important parameters for EAHE and GSHP systems are the thermal conductivity of soil, the water content present in the ground will significantly improve the performance of the systems, and further benefits are discussed in this study.

The present work aims to investigate the effects of various additives on the stability of graphene nanoplatelet (GnP)–based nanofluid phase change material (NFPCM) for cold thermal energy storage (CTES). The NFPCMs are prepared by dispersing six different types of surfactants (anionic, cationic, and non-ionic types) in deionized (DI) water at a mass ratio of 1:0.5 GnP to surfactant. NFPCMs can be found to be stable with a suitable surfactant even after 30 days using zeta-potential distribution, UV–vis absorption, visual inspection, and sedimentation tests at low temperature. The maximum enhancement in thermal conductivity of 8.3% and 48.3% is recorded in both liquid and solid states for the NFPCM with gum arabic (GA) respectively. The viscosity was enhanced by the dispersion of non-ionic surfactants, where the anionic surfactant (sodium dodecylbenzene sulfonate (SDBS)) NFPCM had a 29.9% lower augmentation compared to DI water. Furthermore, differential scanning calorimetry (DSC) results demonstrate that the phase change properties of the NFPCM are significantly affected depending on the surfactant type. The maximum phase change enthalpy is lowered (10.6%) in the Tween 80 NFPCM as compared to the base PCM. The long-term stability with the highest thermal transport property of the NFPCM storage unit integrated with the chiller is capable of achieving environmental pollution remediation by minimising the time it takes to charge the PCM.

An effort is being conducted to enhance some characteristics of self-compacted concrete (SCC) and clean the environment through the addition of waste plastic fibers resulting from the cuts of waste medical radiology. A number of tests were carried out to examine the impact of waste medical radiology (WMR) fiber additions with various aspect ratios and various percentages on SCC characteristics. Thus, various SCC mixes were designed at a constant water-to-binder ratio of 0.33 and 550 kg/m³ of binder content. The four groups of WMR fiber content were specified with different aspect ratios of (0, 40, 50, and 60) with various ratios of (1%, 1.25, and 1.5%) by volume of concrete. The workability characteristics of SCC mixes were determined by fresh density, segregation resistance, L-box height ratio, T50 slump with V-funnel flow time, and slump flow diameter. Also, the measurement of thermal conductivity, compressive, flexural, and splitting tensile strengths were performed at 28 days for SCC mixtures. The findings revealed that WMR fibers have a negative impact on the fresh characteristics of SCC except for segregation resistance, which improved. However, the results of splitting tensile and compressive strengths were enhanced at 1% WMR fiber content with various aspect ratios then decreased. However, all results of flexural strength were reduced in comparison with the control mixture excluding samples containing 1% WMR fibers with an aspect ratio of 50 which showed a higher result. The outcomes of thermal conductivity were reduced with the usage of various WMR fiber percentages and various aspect ratios in comparison with the control mixture, and the best result was obtained at 1.25% WMR fiber with an aspect ratio of 50.

The need for environmental preservation requires civil engineering to reach new concepts and technical solutions aiming at the sustainability of its activities and products. In this context, this study aimed to evaluate the effect of using different types and percentages of vegetable particles on the physical, mechanical, and thermal properties of soil–cement bricks. Bamboo, rice husk, and coffee husk particles at 1.5 and 3% percentages and a control treatment not using the particle were evaluated. The chemical properties, shrinkage, compaction, consistency limits, and grain size were characterized for the soil; and the anatomical, chemical, and physical properties for the lignocellulosic particles. The bricks were produced using an automatic press and characterized after the curing process for density, water absorption, porosity, loss of mass by immersion, compressive strength, durability, and thermal conductivity. The increase in the lignocellulosic waste percentage caused a mechanical strength decrease and bricks’ porosity and water absorption increase. However, it caused a decrease in density and an enhancement in loss of mass and thermal insulation properties. The bricks produced with rice husk obtained the best results in terms of mechanical and thermal properties, and were still among the best treatments for physical properties, standing out among the lignocellulosic waste as an alternative raw material source for soil–cement brick production.

Building-integrated photovoltaic systems’ electrical efficiency decreases when their operating temperature increases. To overcome this drawback, the use of the PCM as a passive method to improve the thermal and electrical performances of the system is highly recommended. Yet pure phase change materials are known for low thermal conductivity. Inserting fins in the PCM enhances its thermal conductivity leading therefore to an improvement in the heat transfer rate. The present investigation carried out the optimization of the BIPV-FPCM system to reduce BIPV system temperature at real Tunisian climatic conditions. The best inclination angle of BIPV-FPCM is carried out. Moreover, the suitable depth of the FPCM box is evaluated. BIPV, BIPV-PCM, and BIPV-FPCM systems are compared. In the present thermodynamic work, the fusion and solidification processes of the FPCM were analyzed. In addition, space between successive fin effect, fin length, and position effect on BIPV electrical and thermal performances had been investigated. Interesting findings showed that the decrease in the tilt angle of the module enhances the heat transfer rate in the FPCM due to the improvement of the convection heat transfer rate in the melted PCM. Thirty degrees is found the most optimal tilt angle with respect to the horizontal where the received solar radiation increases with the decrease of the tilt angle from 90° to 30°. Results prove that the best fin number to enhance performances of the BIPV-PCM system is 3 where 6 cm is found to be the best PCM box depth. Eventually, fin positioning is so important to improve the rate of heat transfer rate by promoting natural convection in the PCM. Results reveal that “full fins” and “front fins” scenarios are the best cases for improving the melting rate and performances of the BIPV-FPCM system.

The present research work aims to investigate the energy saving aspects in cool thermal energy storage system (CTES) by improving the thermophysical properties of deionized (DI) water. The influence of phase change enthalpy, specific heat, thermal conductivity, and cooling rate of the DI water for the dispersion of chemically functionalized multi-walled carbon nanotubes (f-MWCNT) is studied experimentally. The covalent functionalization method is used to modify the surface of the multi-walled carbon nanotubes (MWCNT) with the use of concentrated nitric acid. The nanofluid phase change materials (PCMs) in different mass concentrations (0.25%, 0.50%, and 0.75%) were prepared by dispersions of the f-MWCNT in DI water. The minimum reduction in enthalpy (4.01%) was recorded for the nano-PCM with 0.75% f-MWCNT as compared to the base PCM with 0.5% of sodium dodecyl benzene-sulfonate (10%). The thermal conductivity enhancement of 53.15% and 28.2% was recorded in both states for the nano-PCM (with 0.75%) at the temperature of − 10 °C and 5 °C respectively. Also, the enhancement of 30% and 23% in cooling rate is recorded for the dispersion of maximum concentration of f-MWCNT at the HTF temperatures of − 8 °C and − 6 °C, respectively. It is proven from the above findings that the dispersion of f-MWCNT reduces the subcooling and facilitates the running of the CTES system at a higher operating temperature.