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A cost-effective green engineered magnesium oxysulfide cement-based composites (MOSC-ECC) which was prepared with magnesium oxysulfate cement (MOSC) and large-volume solid waste (slag) in this paper. The macro and micro mechanical properties, thermal conductivity, water resistance, evolution of hydration products and microstructure of MOSC-ECC were studied. The energy consumption, carbon emissions, and cost of MOSC-ECC were calculated and compared with traditional ECC. Test results showed that adding slag instead of light-burned MgO can increase the strain-hardening strength and energy indices of MOSC-ECC, and improve the ductility. In addition, the incorporation of slag lowered the proportion of 5Mg(OH) 2 ·MgSO 4 ·7 H 2 O phase (517 phase), led to a decrease in the strength, density and thermal conductivity of the MOSC-ECC. Compared with traditional OPC-based ECCs, the prepared MOSC-ECC showed a reduction in embodied energy by approximately 32 %, a reduction in CO 2 emission of around 60 %, and a reduction in material costs more than 38 %. Therefore, slag can be used as the main component of MOSC-ECC, and the dosage can be up to 50 % by weight of MgO, which has obvious economic and environmental benefits. • Incorporating slag instead of MgO can improve ductility and reduce density and thermal conductivity. • Replacing MgO with slag reduces the formation of 517 phase. • MOSC-ECC shows obvious superiority in environmental impact and material cost. [ABSTRACT FROM AUTHOR]

The influence of NaOH on pore structure, reaction kinetics, volume, and morphology of reaction products in high-volume-fly-ash mixtures was explored by two mixing methods: (i) direct addition of 0.2 M, 0.5 M and 1.0 M NaOH solution into cement-FA powder, and (ii) pre-dissolving FA into NaOH solution before mixing with cement. The pre-dissolution technique improved early-age mechanical performance by enhancing Si release, aiding the expedited precipitation of extra C-A-S-H gel. Both methods improved the degree of FA reaction and alite/belite hydration. However, 1.0 M NaOH negatively affected the strength and microstructure properties due to undesirable silica-gel formation, C-A-S-H gel carbonation, and increased capillary pore volume. NaOH concentration has affected the packing density of C-A-S-H gel, where high-pH systems exhibit loosely packed sheet-like clusters. Ca/Si of C-A-S-H gel in low and high pH systems evolved with increased curing age, with low pH system exhibiting high Ca/Si at 90 days. • Pre-dissolution of fly-ash enhances early age strength of HVFA mixtures. • NaOH addition improves FA reaction degree, and alite and belite hydration. • Morphology of C-A-S-H gel was changed in low pH to high pH environment. • HVFA pastes with high NaOH contents showed lower strength. [ABSTRACT FROM AUTHOR]

Like protein-coding genes, long noncoding RNA (lncRNA) genes are composed of introns and exons. After their transcription, lncRNAs are subject to constitutive and/or alternative splicing. Here, we describe the current knowledge on lncRNA splice variants and their functional implications in cell biology. [ABSTRACT FROM AUTHOR]

In this study, machine controlled high compaction force was used to produce an innovant, sustainable and energy efficient bio-composite based on magnesium phosphate cement (MPC) as binder and corn stalk as bio-aggregate. Characterization of corn stalk was investigated by water absorption, image processing, scanning electron microscopy (SEM), x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis. Mechanical, hygrothermal, aging and microstructural properties of bio-composites were examined. Compressive strength of bio-composites compacted by the machine was considerably higher than the manually compacted bio-composites. Capillary absorption and water absorption of bio-composites were lowered due to high compaction force. Increase in the temperature slightly affected the thermal properties of bio-composites. All the bio-composites were rated from good to excellent hygric regulators based on their moisture buffer performance. Influence of high compaction on the thermal, hygric and moisture buffer properties of bio-composites was discernible. Development of molds was detected on the specimens subjected to higher relative humidity level. Finally, formulated energy-efficient and sustainable bio-composites were classified into structural and insulation grade concrete. [ABSTRACT FROM AUTHOR]

This work addresses the preparation of self-flowing lightweight aggregate foamed concrete (LAFC) resulting from the mixing of stable foam, expanded clay aggregate (ECA) and silica fume (SF) as main raw materials. Formulated LAFC mixtures were tested for the mechanical, thermal, sorption and high-temperature resistance properties. Results showed that the increase in the volume of foam from 0% to 20% considerably improved the flowability of LAFC and LAFC mixtures were categorized into high stable visual stability index. Compressive strength of LAFC mixtures was reduced from 24.75 MPa to 21.10, 15.95 and 12.05 MPa respectively when foam volume was increased from 0% to 10, 15 and 20%. Thermal conductivity of LAFC mixtures was 0.84, 0.77, 0.65 and 0.53 Wm−1K−1 for the 0, 10, 15 and 20% foam volume respectively. The addition of SF enhanced the strength and thermal conductivity of LAFC mixtures. Sorption coefficient and porosity of LAFC were gradually increased from 0.22 to 0.85 kgm−2min−0.5 and 25.68–39.74% by increasing the volume of foam from 0% to 20%. However, incorporation of SF reduced the sorptivity and porosity of LAFC. Effect of high temperature was more prominent on the compressive strength of LAFC as compared to the density of LAFC. [ABSTRACT FROM AUTHOR]

Abstract Chemical fertilizer is a commonly used practice in farms to increase crop quality and yield. Biochar improves nutritional status and quality of the soil. Whereas, there are few relative reports on the effectiveness of soil bacterial community structure and functional diversity by biochar and chemical fertilizer in the red soil. We utilized 16S rRNA sequencing to explore specific changes in structure and functions of bacterial community. The results indicated that amendment of biochar and fertilizer to red soil exhibited a significant effect on Proteobacteria. The combination of biochar and chemical fertilizer (FC) was the most beneficial to the bacterial community changes in red soil. The change of bacterial composition during FC treatment promoted the circulation of soil nutrients, improved the poor nutrient environment, and disease resistance and stress resistance of plants. Through the functional prediction of 16S, we confirmed that FC treatment significantly improved the functional abundance of red soil bacteria. In addition, biochar led to a slight change in the bacterial structure of red soil due to the low abundance of new species. The impact of chemical fertilizer on bacterial community structure was more significant under red soil conditions, but it significantly reduced the functional abundance. It could be suggested that the impact of biochar and chemical fertilizer on the bacteria community and bacterial functional diversity in red soil was different. The most effective treatment in red soil could be the combined application of biochar and fertilizer. Graphical abstract Unlabelled Image Highlights • Examined effect of biochar and fertilizer on soil bacterial community and its functioning for short incubation • Proteobacteria showed highest significant effects by biochar and fertilizer amendment. • Fertilizer amendment led to decrease in bacterial richness and evenness and functional abundance. • Biochar resulted in least influence on functional abundance and bacterial community. • The biochar in combination with fertilizer was most effective compared to corresponding single treatments. [ABSTRACT FROM AUTHOR]

This study investigated the influence of ultrafine fly ash (FA) on the mechanical properties, elevated temperature resistance and water stability of basalt fiber reinforced magnesium phosphate cement, and synergy mechanism was examined with the help of X-ray diffraction (XRD), thermogravimetric analysis (TGA), mercury intrusion porosimeter (MIP) and scanning electron microscopy energy dispersive spectroscopy (SEM/SEM-EDS) analysis techniques. Experimental results showed that incorporation of FA improved the mechanical properties, temperature resistance and water stability of MPC composites. TGA results exhibited that the mass loss of MPC composites was gradually reduced by increasing the percentage of FA. MIP analysis showed that cumulative pore volume, volume percentage of large pores and mean pore diameter of were decreased with the addition of FA. XRD and SEM-EDS analysis of MPC composites revealed the formation of secondary reaction products, that could be possibly responsible for the superior properties of FA/MPC composites. Importantly, the results of all characterization techniques corroborated with the mechanical results of MPC composites. [ABSTRACT FROM AUTHOR]

Highlights • Use of steel slag powder in magnesium phosphate cement (MPC) increased its water resistance. • Significant increase in the compressive strength of MPC mortar specimens with addition of steel slag powder. • Formation of new hydration products which supported the improvement mechanism of steel slag powder. Abstract Magnesium phosphate cement (MPC) belongs to the family of chemically bonded phosphate ceramics and exhibits certain outstanding qualities. The current study investigated the effects of steel slag powder (SSP) on the properties of MPC mortar. MPC mortar specimens with different content of SSP were prepared and their workability, mechanical properties and water resistance were tested. Moreover, microstructure and phase composition of MPC paste were examined by Scanning Electronic Microscopic (SEM) and X-ray diffraction (XRD) techniques. It was found that the incorporation of SSP can promote early hydration rate. A significant improvement in the later stage mechanical strength was observed but early strength was reduced. Water resistance of MPC mortar specimens was improved by increasing the percentage of SSP from 0% to 30%. Finally, XRD and SEM analysis of MPC pastes corroborated with the mechanical strength results and confirmed the formation of secondary reaction products along with the main hydration products struvite and residual magnesia. [ABSTRACT FROM AUTHOR]

Highlights • The effect of SF and BF on the mechanical properties of MPC mortar was investigated. • The addition of SF and BF improved the strength properties of MPC mortar. • Hydration products of MPC system were analyzed using XRD, SEM and SEM-EDS methods. • Secondary hydration products were observed besides the struvite formation. Abstract This paper evaluates the effect of silica fume (SF) and basalt fibers (BF) on the mechanical properties and microstructure of magnesium phosphate cement (MPC) mortar. Several MPC mortar mixtures with different contents of SF and BF were prepared. Experimental results revealed that the compressive strength and flexural strength of MPC mortar was increased by increasing the percentages of SF from 0% to 10%. Incorporation of BF improved the flexural strength and post-peak flexural behaviour of the load-deflection curve of MPC mortars, but its effect on the compressive strength was insignificant. MPC matrix with 10%SF and 0.5%BF demonstrated the highest compressive and flexural strength of 49.42 MPa and 5.31 MPa respectively at the 28 days. XRD and SEM analysis showed that control mixture without SF and BF contained more unreacted magnesia and struvite as compared to MPC mortars containing SF and BF. Moreover, SEM-EDS analysis of MPC mixtures incorporating SF and BF showed that SF and fly ash (FA) reacted within the MPC paste system to produce the secondary hydration products. It was postulated that magnesium silicate, aluminium or silicon phosphate phases were formed during the reaction of SF and FA in the MPC system. These secondary products tend to improve the bonding of solid phase and hence mechanical properties of MPC mortar. Finally, SEM-EDS analysis also confirmed the excellent interaction of BF with the MPC hydration products. [ABSTRACT FROM AUTHOR]

A series of palladium (II) complexes ( 1–8 ) with N-(acyl)-N′,N′-(disubstituted) thioureas and phosphine ligands were synthesized and characterized by FT-IR, multinuclear ( 1 H, 13 C & 31 P) NMR spectroscopy and elemental analysis. The crystal structures of the Pd(II) complexes ( 1 ) & ( 5 ) of the type Pd II (L- O , S )(Ĺ- P )Cl were determined by single crystal X-ray diffraction analysis. They adopted the square planar geometry, where the N-(acyl)-N′, N′-(disubstituted) thioureas showed bidentate coordination mode in a chelating fashion through O and S donor atoms, and phosphine ligands through P atom at palladium centre. In vitro cytotoxic profile of the synthesized palladium(II) complexes ( 1–8 ) was determined against lung squamous carcinoma and breast adenocarcinoma cell lines. These complexes were also tested for promastigote forms of Leishmania tropica to evaluate their antileishmanial activity. The complexes bearing 2,4-dichlorophenyl moiety among the screened complexes were the most active with IC 50 values 1.72 ± 0.27, 2.12 ± 0.44, 1.57 ± 0.16 µM against the targets MDA-MB-231, H-157, Leishmania tropica , respectively. [ABSTRACT FROM AUTHOR]

The Sn-Ag 3 . 0 -Cu 0 . 5 lead free solder ( LFS ) alloy is mostly used as good alternative as compared to conventional Tin-Lead ( Sn-Pb ) due to its good mechanical properties and no harmful effect on environment but it stills has some problems to be solved regarding the growth formation of intermetallic compounds ( IMCs ). The IMCs present inside the bulk tin ( Sn ) matrix grow at high temperature and hence their impact on mechanical properties becomes more significant. In this work the effects of lanthanum ( La ) doping of Sn-Ag 3 . 0 -Cu 0 . 5 is investigated as function of IMCs growth and mechanical properties including yield strength ( YS ) and ultimate tensile strength ( UTS ) under different thermal aging temperatures. The selected La concentration in this study is 0.4 wt%. The aging time is 50 h and thermal aging temperatures are 60 °C, 100 °C and 140 °C. The microstructure examination before and after thermal aging is observed using scanning electron microscopy ( SEM ) followed by image analysis to estimate the nature of IMCs . The chemical composition is confirmed with energy dispersive X-ray ( EDX ). The YS and UTS are also examined before and after thermal aging for the un-doped and doped samples from stress-strain curves using universal testing machine ( UTM ). It is investigated that inclusion of 0.4 wt% La into Sn-Ag 3 . 0 -Cu 0 . 5 solder system results in increasing the IMCs growth rate and hence mechanical properties reduced. It is also observed that the microstructure becomes coarsen after thermal aging due to growth of average IMCs particle size with significant decrease in YS and UTS . Further, mathematical relations with minimum error are developed to predict mechanical properties ( YS and UTS ) at various levels of aging temperature, showing a reciprocal relationship between aging temperature and mechanical properties. [ABSTRACT FROM AUTHOR]

Flue gas residues (FGR), a waste from incineration plant was utilized as an alternative alkaline activator to energy intensive and costly commercial activators. Fly ash (FA) and slag were used as precursors materials along with the FGR to produce low-carbon and cost-effective alkali-activated materials (AAMs). Reaction products and micromechanical properties were investigated by advanced microstructure analysis techniques. Results from the infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and nanoindentation indicated that reaction products were comprised of N-A-S-H gel as a major reaction product along with the hybrid gel (C–N-A-S-H) and C-A-S-H gel. SEM-EDS and nanoindentation results showed that the formation of C-A-S-H gel was directly related to the content of FGR. The increase in volume of Ca-based reaction products (C–N-A-S-H and C-A-S-H) was associated with the activation of slag in presence of Na 2 SO 4. Besides N-A-S-H gel, some new reaction products (zeolite, apatite and berlinite) were also observed from XRD analysis of pastes. The compressive strength of AAMs was in the range of 33.5–39.6 MPa and was in line with microstructure analysis results. Leaching concentrations of Ag, Ba, Cd, Cu and Zn heavy metals in FGR were 0.10, 0.40, 0.63, 0.26 and 1.65 mg/L respectively and below the regulatory limits and it was classified as a non-hazardous material. [ABSTRACT FROM AUTHOR]

This paper provides a detailed underlying mechanism of gel composition of hybrid alkali-activated fly ash/slag (AAFS) pastes prepared by utilizing the air pollution control residue (APCr, a highly alkaline waste containing 38.3% of Na 2 O content by mass) as a partial replacement (8%, 16% and 24% replacement by mass) of energy-intensive commercial sodium silicate (CSS) activator. AAFS pastes containing APCr as a partial replacement of CSS showed the strength, micromechanical and microstructure properties equivalent to the reference AAFS paste without APCr (R-0). SEM-EDS, FTIR spectral subtraction, and nanoindentation results showed that reaction products in AAFS pastes were composed of geopolymer gel (N-A-S-H), cross-linked gel (C–N-A-S-H) and alkali-activated gel (C-A-S-H) contributing to 60–66% of paste volume. Reaction products were more dominated by calcium-rich gels (C-A-S-H or C-(N)-A-S-H) as compared to N-A-S-H gel in all AAFS pastes. The heat of hydration and thermogravimetric results confirmed the slow rate of reaction of APCr-AAFS pastes at the early age but a higher rate of reaction at the silater stage which contributed to achieve a similar strength as control paste (R-0). [ABSTRACT FROM AUTHOR]

Integrating phase change materials (PCMs) into building materials has been widely used to improve the energy efficiency of buildings, in which microencapsulation and shape stabilization of PCMs are considered as two most effective solutions. In this study, artificial geopolymer aggregate (GPA) was employed as a novel PCM carrier for energy storage purposes. Detailed investigations were conducted into the physical, mechanical, and thermal properties of GPA-PCM, which can be engineered through different raw material selections (e.g., slag content, water/binder ratio, and incineration bottom ash (IBA) content). It was demonstrated that increasing the IBA content is an efficient means to increase the porosity of GPA, an index of the capacity to accommodate PCM. Up to 16 wt% PCM could be absorbed into the GPA through vacuum suction, resulting in a significant melting enthalpy of 24.74 J/g. Besides, GPA-PCM could achieve an excellent mechanical strength greater than 53.2 MPa and thermal conductivity of 0.510–0.589 W/mK. The time-temperature history curves of GPA revealed that up to 10.5 °C of thermal regulation was achieved due to PCM impregnation. The developed GPA-PCM composites facilitate an innovative and low-carbon solution for utilizing PCMs in construction for temperature-regulating and energy-saving purposes. [ABSTRACT FROM AUTHOR]

The massive influx of Rohingya refugees in Cox's Bazar district of Bangladesh has created a severe humanitarian crisis, which has been exacerbated by the COVID–19 pandemic. The research focused on the most vulnerable groups (MVGs) of Rohingya and adjacent host communities, such as pregnant and/or lactating women, elderly people (64+ years), persons with disabilities (PWD), single female household heads, and adolescents, with the aim to assess the vulnerability among the MVGs and between the households in both communities by developing a gender-based vulnerability index (GBVI), using data from a cross-sectional study in selected Rohingya camps and surrounding host communities. The GBVI―developed as a linear combination of several indicators under nine different themes reflecting vulnerabilities in humanitarian crises―was used to classify the households of both communities into three levels of vulnerability: low (bottom 33.33%), medium (middle 33.33%) and acute (upper 33.33%). Findings show the intensity of vulnerability is significantly greater among the Rohingya households than those in the host community; almost 65% of Rohingya households were 'acutely vulnerable' compared to 2% of host households. In both communities, female-headed households (including single female) are found to be more vulnerable (the highest percentage of households with acute vulnerability), followed by households with elderly and PWDs. Further analysis suggests that households with acute vulnerability in both communities are deprived of receiving certain services, such as COVID–19 monetary support and disability allowances. It is recommended to identify acutely vulnerable households consisting of MVGs from both communities, understand their needs, and implement urgent policies/interventions. [ABSTRACT FROM AUTHOR]

The pluripotency and differentiation states of embryonic stem cells (ESCs) are regulated by a set of core transcription factors, primarily Sox2, Oct4, and Nanog. Although their transcriptional regulation has been studied extensively, the contribution of posttranslational modifications in Sox2, Oct4, and Nanog are poorly understood. Here, using a CRISPR-Cas9 knockout library screen in murine ESCs, we identify the E3 ubiquitin ligase Stub1 as a negative regulator of pluripotency. Manipulation of Stub1 expression in murine ESCs shows that ectopic Stub1 expression significantly reduces the protein half-life of Sox2, Oct4, and Nanog. Mechanistic investigations reveal Stub1 catalyzes the polyubiquitination and 26S proteasomal degradation of Sox2 and Nanog through K48-linked ubiquitin chains and Oct4 via K63 linkage. Stub1 deficiency positively enhances somatic cell reprogramming and delays differentiation, whereas its enforced expression triggers ESC differentiation. The discovery of Stub1 as an integral pluripotency regulator strengthens our understanding of ESC regulation beyond conventional transcriptional control mechanisms. [Display omitted] • Stub1 maintains protein homeostasis of Sox2, Oct4, and Nanog in ESCs via the proteasome • Stub1 degrades Sox2 and Nanog through K48 linkage and Oct4 through K63 linkage • Stub1 increases trigger ESC differentiation, while its attenuation enhances pluripotency Using gene knockout screening in embryonic stem cells, Mamun et al. reveal that the E3 ligase Stub1 controls the proteostasis of the core pluripotency factors Sox2, Oct4, and Nanog. Subsequent analysis reveals that Stub1 balances cell fate decisions between pluripotency and differentiation in embryonic stem cells. [ABSTRACT FROM AUTHOR]

Highlights: [•] A hybrid machining technique is introduced for the machining of beta titanium alloy. [•] This technique resulted significant reduction in cutting forces and improvement in surface roughness. [•] Experimental results were validated with the developed finite element model. [Copyright &y& Elsevier]

• Mortar composites with different content of PVA fibers were prepared. • Mechanical properties of mortar composites were evaluated. • The addition of PVA fiber improved strength properties and ductility performance. • Water absorption and porosity of mortar composites showed a direct relationship. This paper studies the influence of polyvinyl alcohol (PVA) fibers on the mechanical and water resistance properties of fiber-reinforced magnesium phosphate cement (FR-MPC) mortar composites. The dosage of fiber was kept at 0%, 0.13%, 0.25%, 0.5% and 0.75% respectively. The increase in fiber content gradually reduced the fluidity of FR-MPC composites. The addition of PVA fibers increased the water absorption, porosity, and loss in mass. The compressive, three-point flexural, four-point flexural, and splitting tensile strength were improved with the addition of PVA fibers. In all cases, an amount of 0.5% PVA fiber was found as an optimum dosage. Fracture toughness and ductility performance were enhanced due to inclusion of fibers. However, there was a continuous decrease in water resistance with the increase in fiber content. Observations by SEM revealed that fibers show non-uniform distribution at a high dosage of 0.75%, which also corroborated with the findings of mechanical properties. [ABSTRACT FROM AUTHOR]

Abstract: Accurate weather forecasts are necessary for planning our day-to-day activities. However, dynamic behavior of weather makes the forecasting a formidable challenge. This study presents a soft computing model based on a radial basis function network (RBFN) for 24-h weather forecasting of southern Saskatchewan, Canada. The model is trained and tested using hourly weather data of temperature, wind speed and relative humidity in 2001. The performance of the RBFN is compared with those of multi-layered perceptron (MLP) network, Elman recurrent neural network (ERNN) and Hopfield model (HFM) to examine their applicability for weather analysis. Reliabilities of the models are then evaluated by a number of statistical measures. The results indicate that the RBFN produces the most accurate forecasts compared to the MLP, ERNN and HFM. [Copyright &y& Elsevier]

Due to the recent surge in the lithium slat industry, a high amount of lithium slag (LS) is generated as industrial waste and stacked open, causing environmental pollution and occupying land resources. In this regard, this research very first time investigates the use of LS to prepare and study the physical and mechanical properties of magnesium ammonium phosphate cement (MAPC). It is believed that results will be helpful in reducing the burden of LS on the environment and in improving the construction sector sustainability. For this purpose, LS was replaced with the MAPC by 10%, 20%, 30%, 40%, and 50%. A gradual increase in LS quantity decreased the fluidity and increased the setting time of LS-MAPC mortars. Comparison of results showed that heat curing of samples at 70 °C for 24 h produced LS-MAPC mortars having high strength than the air-curing. Among all mixtures, a replacement level of 10% was found as the optimum dosage and produced the best results as compared to other mixtures. Mechanical properties of LS-MAPC mortars were improved when amount of MAPC replacement by LS was 10%. Water absorption and porosity of mortars showed a direct relationship with the percentage of LS. Reaction products were studied by X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscope analysis and their findings corroborated with experimental results. • Lithium slag was used to replace the magnesium phosphate cement. • Influence of lithium slag on flowability and setting time was studied. • Air curing and heat curing methods were employed to determine the suitable curing regime. • Lithium slag improved the flexural and compressive strength at optimum dosage of 10%. • Microstructure results of cement pastes supported experimental findings. [ABSTRACT FROM AUTHOR]

Traditional binders (ordinary Portland cement; OPC and lime) due to their high alkaline nature show poor bio-compatibility and degradation of hydration products when mixed with the lignocellulosic materials. As a result, produced plant-concrete composites (PCC) exhibit inferior mechanical and durability properties. In this regard, this paper adopts the approach of pretreatment of corn stalk particles (alkalization and hydrophobic pretreatment) and use of alternative binders (geopolymer; GP and magnesium phosphate cements; MPC) to address these performance related issues. Results showed significant improvement in microstructure of PCCs and interface bonding between the binders and corn stalk aggregates due to hydrophobic pretreatment. Among the PCCs containing different type of binders, MPC based PCCs exhibited superior performance in term of strength, and hygroscopic properties as compared to OPC and GP based PCCs. Reduction in porosity and drying shrinkage was also prominent for the PCC prepared with GP and MPC binders and hydrophobic pretreated corn stalk aggregates. However, thermal conductivity of PCCs was increased for PCCs containing pretreated corn stalk aggregates. [ABSTRACT FROM AUTHOR]

• An artificial intelligence-based gene expression programming approach was used for modelling the performance of bio-composites. • Mathematical models were proposed for density, compressive strength and thermal conductivity of bio-composites. • Performance of the proposed mathematical models was validated using statistical parameters and performance indices. • The proposed models depicted high degree of generalization capability and predictability. Giving the high amount of carbon and energy emission from the use of traditional building materials, the use of bio-composites made from industrial crops especially hemp has caught attention from researchers in recent years. These bio-composites not only enhance the thermal performance of buildings but also promote sustainable development due to their eco-friendly nature. Due to their highly heterogeneous nature, however, most of the existing studies on the bio-composites have only focused on experimental investigations, while mathematical modeling of physical, thermal and mechanical properties of bio-composite remains a challenge for the researchers. In this paper, an artificial intelligence (AI) based gene expression programming (GEP) technique is used to develop the mathematical models for predicting the dry density, compressive strength and thermal conductivity of hemp-based bio-composites. A large amount of database was established based on past studies and the most influential parameters were identified by several trial analyses. The proposed mathematical models showed a high correlation with the experimental results. All the models passed the statistical and performance index checks showing strong predictability, generalization capability and high accuracy of GEP-AI models. Comparison of results with the regression analysis techniques further proved the superiority of GEP-AI models over the traditional methods. [ABSTRACT FROM AUTHOR]

[Display omitted] • Vegetal concrete was exposed to extreme weather conditions. • Red mud and fly ash were added to enhance the sustainability of concrete. • Loss in mass and compressive strength of vegetal concrete was measured. • Aging of vegetal concrete does not affect thermal properties of vegetal concrete. This paper studies the durability properties of vegetal concrete exposed to extreme environmental conditions including immersion weathering, outdoor weathering, salt attack, and freeze-thaw attack. Magnesium phosphate cement (MPC) binder containing high percentage of red mud and fly ash was mixed with the corn stalk based vegetal aggregates. It was found that all samples exposed to immersion weathering, outdoor weathering, and freeze-thaw attack showed a loss in mass, reduction in sample area, and decrease in compressive strength, which was associated with the dissolution and leaching out of the binder. Increase in the mass and swelling was observed for the vegetal concrete mixtures immersed into salt solution due to formation of salt layer on the surface of binder and vegetal aggregate. It was concluded that incorporation of fly ash, high compaction of samples, and pretreated aggregates improved the durability performance of vegetal concrete against extreme weather conditions. [ABSTRACT FROM AUTHOR]

• Optimization of three types of binder was conducted. • Effect of type of binder on interface bonding with bio-aggregate was studied. • Influence of alkali and hydrophobic treatment methods was investigated. • Thermal, mechanical and microstructure properties of bio-concrete were studied. Due to their high alkaline natrure, ordinary Portland cement and lime based traditional binders show poor compatibility with the bio-aggregates. As a results, produced bio-concretes show prolonged setting time, poor mechanical and durability properties. In order to use the traditional binders in preparing the bio-concrete, the use of expensive treatment methods to improve bio-comptability of these binders become inevitable. In this regards, this research aims to solve the bio-compatibility issues of traditional binders and develop new green binders to prepare bio-concrete. In the first part, mechanical and chemical characterization (through XRD, DTG/TGA and SEM) of Portland cement (OPC), geopolymer (GP) and magnesium phosphate cement (MPC) binders was carried out. Optimized binders from each group were then further used to produce bio-concretes. In the second part, influence of type of binder and pretreament on the properties of bio-concrete was examined. It was observed that hydrophobic treatment was most efficient and increased the amount of hydration products (studied through XRD, FTIR and SEM) and bio-compatibility of OPC and GP binders. However, MPC binder was naturally compatible with the bio-aggregates due to its low pH value and do not necessarily demand any pretreatment of bio-aggregate. It was concluded that, MPC based bio-concrete shows high performance as compared to OPC and GP based bio-concrete. [ABSTRACT FROM AUTHOR]

• A new bio-based capillary active insulation material was developed. • Mould risk of walls containing capillary insulation material was reduced. • Capillary insulation material reduced the heat loss through the wall. • Uninsulated reference wall showed the higher risk of condensation. This paper studies the influence of a new bio-based capillary active insulation (CAI) materials (corn stalk based vegetal derived concrete namely CS-1 and CS-2) and two traditional insulation materials (aerated autoclaved concrete (AAC) and aerated insulation brick (IB)) on the hygrothermal properties of multilayer wall. The reference wall consists of solid brick masonry plastered on the internal and external sides. Walls based on CAI materials consist of an extra layer of insulation and weather-resistive barrier (WRB) on the façade surface. Simulations were performed under the natural climatic condition of hot-humid and cold regions. Optimum thickness for the bio-based CAI materials to be used as internal insulation was 100 mm beyond which higher insulation thickness triggered the risk of mould growth. All walls based on CAI insulation materials (CS-1, CS-2, AAC, and IB) showed the mould index (MI) within the acceptable range. Bio-based CAI materials showed considerable improvement in the temperature and relative humidity at the interior surface. CAI materials reduced the heat losses through the wall by 58–69% as compared to the reference wall. Drying behavior of the wall was significantly improved with the combination of CAI and WRB and no risk of condensation was observed in the walls. [ABSTRACT FROM AUTHOR]

• One-part Alkali activate mortars based on fly ash and slag were prepared. • Effect of different curing condition on the properties of alkali activate mortar were studied. • Alkali activated mortars exhibited good mechanical properties at ambient condition. • Alkali activated mortars showed good resistance against sulfate and acid attack. One-part AAM is low carbon binder having low energy requirements coupled with excellent working properties and strength characteristics. This study examined the influence of silica fume, magnesia, cement clinker, and metakaolin on the shot term and long term hardened properties and durability performance of one-part alkali-activated (AAM) mortars. The durability of AAM mortars was investigated by exposing the samples to sodium sulfate and sulfuric acid solution for 270 days. Fly ash and ground granulated blast furnace slag were used as main precursors in control mortar and were replaced by silica fume, magnesia, cement clinker, and metakaolin admixtures to evaluate their influence. Admixtures were used at replacement level of 1.5%, 3% and 4.5%. Results revealed a significant improvement in long term compressive strength and water absorption performance of one-part AAM with the increase in admixture content. In addition, the AAM mortar incorporation various admixtures. Mortar specimens did not show any visual signs of discoloration, change in mass, or length during the immersion in sulfate solution. The residual strength of AAM mortars exposed to sulfate solution was in the range of 83–99%. However, mortars samples exposed to sulfuric acid solution underwent cracking and deterioration with the visible leaching out of binder paste accompanied with significant strength loss. AAM mortars containing 4.5% metakaolin showed the highest residual strength against sulfate and acid attack. SEM analysis shows that alkali activated mortars containing admixtures showed no microcracks and micropores and supported the results of mechanical testing. [ABSTRACT FROM AUTHOR]

• Influence of type of binder on properties of plant aggregate concrete was examined. • Mechanical and hygrothermal properties of plant aggregate concrete were studied. • Thermal conductivity of concrete had inverse relationship with size of plant aggregate. • Produced concrete provided the balance between thermal and structural performance. This study investigated the two innovant and high energy efficient corn stalk concretes based on magnesium phosphate cement (MPC) and ordinary Portland cement (OPC) as binders and corn stalk (CS) as plant aggregate. Three different sizes of corn stalks were employed to produce the concrete. The effect of type of binder and size of corn stalk on the hygrothermal, mechanical and microstructure properties of corn stalk concrete were studied. The results revealed that MPC-CS concrete exhibited higher sorption and water vapor permeability as compared to OPC-CS concrete and both binders showed excellent thermal performance. The size of corn stalk was more influential in changing the water absorption, capillary saturation, and thermal properties. Whereas, MPC-CS concrete showed better mechanical performance as compared to OPC-CS concrete. Microstructure analysis of concrete showed that MPC binder had superior cohesion properties and compatibility with corn stalk as compared to OPC binder, which also validated the mechanical results. [ABSTRACT FROM AUTHOR]

This study extends the application of pyrolyzed biochar and investigates its influence on the mechanical, sorption and microstructure properties of magnesium phosphate cement mortar. Biochar was produced by the pyrolysis of wheat straw biomass by controlled burning and its replacement level was kept up to 1.5%. At the age of 30 days, the compressive and flexural strength of mortar containing 1.5% biochar was 17.3% and 9.0% higher as compared to the control mortar, which was associated with the micro-filler and internal reservoir effect of biochar particles. Inclusion of biochar considerably improved the resistance of magnesium phosphate cement in the water environment. Sorptivity and water absorption of mortar containing 1.5% biochar was reduced by 33.8% and 25% respectively than the control mortar. Biochar densified the microstructure of mortars by filling the microcracks and blocking the pores. X-ray diffraction and Fourier transform infrared spectroscopy did not provide any information about the formation of new hydration products. Elemental analysis of mortar samples using energy dispersive spectroscopy showed the presence of some elements, which indicates the possibility of new hydration products. Based on the positive results in this study, future study will include the detailed chemical effect of biochar on magnesium phosphate cement. Unlabelled Image • Influence of biochar on the properties of magnesium phosphate cement was explored. • Improvement in mechanical properties was observed with the addition of biochar. • Use of biochar increased the water resistance of mortars. • Sorptivity and porosity was gradually reduced with the increase in biochar content. [ABSTRACT FROM AUTHOR]