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In this study, three hydration heat controlling materials (HHCMs), respectively, containing pure hydroxyl (polyvinyl alcohol, PVA), carboxylic (polyacrylic acid, PAA) and ester groups (maleic acid-ethylene glycol ester, P(MA-EG)) were synthesized and mixed with cement-based materials, and the hydration heat and setting time of cement pastes and the SEMI adiabatic temperature rise and strength of mortars were tested. The results showed that PAA and P(MA-EG) reduced the peak value of hydration exothermic rate by 77.45% and 62.28%, respectively, and prolonged 54.14 h and 15.56 h, respectively. Mechanism studies showed that HHCMs containing carboxylic or hydroxyl groups adsorbed on cement particles by Ca2+ complexation, while HHCMs containing ester groups hydrolyzed to carboxylic groups in alkaline cement pastes, which hydrolysis rate changed with the hydration temperature of cement-based materials to regulate the hydration process. This study aims to provide technical feasibility and theoretical basis for exploring new avenues of synthesizing HHCMs with different functional groups. [ABSTRACT FROM AUTHOR]

Ferroaluminate cement is widely used in marine engineering applications owing to the remarkable durability and strength of its main hydrate, Al(Fe)–ettringite. The structure and performance of Al(Fe)–ettringite still require extensive exploration. An Al(Fe)–ettringite molecular model containing different Fe contents (0%, 25%, 50%, and 75%) was developed via Materials Studio. Radial distribution functions, time-correlated functions, and mean square displacement were used to analyze the structure of Al(Fe)–ettringite, after which Al(Fe)– ettringite was prepared using a coprecipitation method. The hydration of Al(Fe)–ye'elimite, the nanoindentation testing, and compressive strength of four ettringite types were assessed to facilitate a comparison with the simulation results. Increasing the Fe content resulted in increased lattice size and density. Fe atoms mainly reacted with Ohs atoms to form Fe–Ohs bonds, resulting in an increased Fe–Ohs bond length, with the Fe atom density resulting in volume expansion and increased density in Al(Fe)–ettringite. At 25% Fe content, the number of Hw–Ow hydrogen bonds in Al(Fe)–ettringite was 1166.14, the MSD value was 1.53 Å2, and the water molecules diffused the fastest. The improved macromechanical properties obtained by adding Fe atoms demonstrate that Fe atom substitution can enhance the ettringite structure. The experimental results validated the simulation results. [ABSTRACT FROM AUTHOR]

Nitrogen oxide emissions have attracted much attention due to their impact on the atmospheric environment and human health. Combined with NO removal in the cement production process, coal gasification slag was used to prepare denitrification materials to decompose NO in cement kilns without the addition of reducing agents. Denitrification materials were synthesized by a chemical precipitation method at different pH. The denitrification mechanism was proposed in this study. The results indicated that the denitrification material prepared at a pH of 7 exhibited the best denitrification performance. The NO decomposition rate first increased and then decreased below 400°C, and then increased as the temperature increased, reaching over 97% above 700°C. In the low-temperature range, Fe(II) was assumed to be active species, and the absorbed NO on the Fe(II) site obtained an electron, which promoted the decomposition of NO. In the high-temperature range, besides the active element Fe, the residual carbon in the coal gasification slag was prone to oxidation-reduction reactions, reducing nitric oxide to nitrogen. A new waste-to-value concept is introduced in this study, which promotes green technology for sustainable development. [ABSTRACT FROM AUTHOR]

In this paper, the strength development of a pure steel slag (SS) system with various concentrations of N,N,N′,N′-Tetrakis-(2-hydroxyethyl) ethylenediamine (THEED) was investigated. The hydration kinetics, pore structure and microstructure of SS pastes with and without THEED were characterized to underscore the working mechanism of THEED. Results show that THEED additions significantly increase the 3, 7 and 28 days compressive strength of hardened SS pastes. The enhancement effect increases with the dosage of THEED. At a concentration of 2000 ppm, THEED increased the compressive strength by 733%, 665%, and 545% at 3, 7 and 28 days, respectively. It is confirmed that THEED additions improve the hydration degree of SS by accelerating hydration of the aluminum phase (C3A, PDF-38-1429; C12A7, PDF-48-1882) and C2F,(PDF 38-0408) to generate Mc (PDF-41-0219) and Pa (PDF-30-0222) in the presence of CaCO3. Also, the hydration degree of silicates is increased by THEED. In this way, THEED additions refine the pore structure of hardened SS paste by increasing the pore volume with a diameter below 300 nm to achieve enhancement. The chelating effect of THEED results in promoting dissolution of SS, which provides the driving force for accelerating SS hydration. [ABSTRACT FROM AUTHOR]

In this work, a metal organic framework (Fe‐MOF) with the effect of absorbing toxic gases and good compatibility was synthesized by chelating a novel organic ligand contained carbonization groups (reacted by tris(hydroxymethyl) aminomethane and 1,4‐piperazine dialdehyde) with iron salt. Then, it was used as the synergist to improve the efficiency of intumescent flame retardant (IFR) within polystyrene (PS) substrate. With the addition of 20% IFR and 2% Fe‐MOF, the obtained PS composites exhibited a limiting oxygen index (LOI) value of 28.3% and a UL rating of V‐0. Moreover, the peak heat release rate (pHRR), total heat release (THR), and total smoke production (TSP) of PS composites were decreased by 77.6%, 35.2%, and 33.7%, respectively. According to the mechanism analysis, it was found that Fe‐MOF mainly acted in the condensed phase, contributing to the existence of dense char residues with the presence of IFR system. In addition, the good compatibility of organic ligand in Fe‐MOF with PS substrate could partially alleviate the deterioration of mechanical properties due to the addition of IFR. For PS‐20%IFR/2%Fe‐MOF, the impact strength was improved from 1.7 kJ/m2 (PS‐22%IFR) to 2.2 kJ/m2, the tensile strength was also increased from 21.3 MPa (PS‐22%IFR) to 22.4 MPa. [ABSTRACT FROM AUTHOR]

It is possible to remove volatile organic compounds containing chlorine (CVOCs, such as chlorobenzene) in a single device designed for selective catalytic reduction of NOX with NH3 for the industries containing CVOCs and NOX. Breaking the efficiency-selectivity trade-off in chlorobenzene oxidation remains a major challenge due to the conjugation of halogen atoms with the benzene ring and the reducing nature of NH3. A stepwise synthesis strategy is demontrated to disperse dual Ru/Cu Lewis acid sites outside and inside the zeolite channel. Under the confinement of zeolite, the Ru4+ Lewis acid site on the external surface of the zeolite promotes chlorobenzene oxidation by weakening the p-n conjugate structure of Cl and benzene ring, while the Cu2+ Lewis acid site within the internal channel converts NOX and NH3 to N2. The mutual interference between catalytic oxidation and reduction is successfully avoided. Therefore, the low toxic CO2 and HCl selectivity experience a considerable increase from 21% to 86%, and from 51% to 94% with 91% conversion of chlorobenzene, while maintaining excellent elimination performance for NO (with N2 selectivity exceeding 90%). The incorporation of separated active sites and reaction spaces into the design may offer potentials for other energy and environmental applications. [ABSTRACT FROM AUTHOR]

Collaborative disposal of sludge has been applied extensively in cement industry kilns, but the influence of organic components in sludge on the selective non-catalytic reduction (SNCR) denitrification is still in highly demanding. This paper focuses the influence of ethanol, n-octane, benzene, and acetone on the SNCR denitrification, and the influence of ethanol are analyzed on SNCR denitrification under different flue gas condition. The result showed that the presence of organic components reduces the reaction temperature of SNCR. When the temperature of SNCR reaction is at 750 ~ 800 ℃, the denitrification rate of four organic components is ethanol > benzene > n-octane > acetone. The optimum denitrification rate on SNCR can reach as high as 90.377% when the reaction condition is the NH3/NO is 1; the ethanol concentration is 1000 ppm; O2 concentration is 2%; and temperature is 750 ℃. The presence of carbon dioxide inhibits the denitrification reaction. With the increase of temperature, the influence of SO2 on the denitrification reaction first increases and then decreases. In this paper, the influence of organic components in sludge on SNCR denitrification will be analyzed, which provides a theoretical basis for the selection of sludge dosing method for cement kiln collaborative disposal. [ABSTRACT FROM AUTHOR]

Collaborative disposal of sludge has been applied extensively in cement industry kilns, but the influence of organic components in sludge on the selective non-catalytic reduction (SNCR) denitrification is still in highly demanding. This paper focuses the influence of ethanol, n-octane, benzene, and acetone on the SNCR denitrification, and the influence of ethanol are analyzed on SNCR denitrification under different flue gas condition. The result showed that the presence of organic components reduces the reaction temperature of SNCR. When the temperature of SNCR reaction is at 750 ~ 800 ℃, the denitrification rate of four organic components is ethanol > benzene > n-octane > acetone. The optimum denitrification rate on SNCR can reach as high as 90.377% when the reaction condition is the NH3/NO is 1; the ethanol concentration is 1000 ppm; O2 concentration is 2%; and temperature is 750 ℃. The presence of carbon dioxide inhibits the denitrification reaction. With the increase of temperature, the influence of SO2 on the denitrification reaction first increases and then decreases. In this paper, the influence of organic components in sludge on SNCR denitrification will be analyzed, which provides a theoretical basis for the selection of sludge dosing method for cement kiln collaborative disposal. [ABSTRACT FROM AUTHOR]

NOx emission from the cement industry have received much attention. In order to reduce the NOx emission in cement kilns, nickel slag was used to prepare the non-ammonia denitrification material, and a denitrification mechanism was proposed in this study. The results showed that the denitrification material prepared at pH 7 exhibited the best denitrification performance. At low temperature, the highest denitrification performance was achieved between 200 and 300 °C with a NO decomposition rate of approximately 40%. Then, the NO decomposition rate increased as the temperature increased, reaching over 95% above 700 °C. The physicochemical characteristics showed that the material had the highest specific surface area and the highest relative Fe content, which benefited the denitrification performance. The divalent iron of the denitrification material was considered the active site for the reaction, and trivalent iron was not conducive to denitrification performance at a low temperature range. After the denitrification reaction, the Fe3+/Fe2+ increased from 0.89 to 1.31. The proposed denitrification mechanism was the redox process between divalent iron and trivalent iron. This study not only recycles industrial waste to reduce solid waste pollution but also efficiently removes nitrogen oxides from cement kilns without ammonia. [ABSTRACT FROM AUTHOR]

In this study, two types of liquid alkali-free accelerators were prepared by aluminum sulfate (AF1) and aluminum mud wastes (AF2), and the life cycle assessment (LCA) in the preparation of AF1 and AF2 was compared. The LCA was considered from cradle to gate including raw materials used, transportation, and accelerator preparation based on the method ReCiPe2016. The results indicated that AF1 had a higher environmental impact in all midpoint impact categories and endpoint indicators than that of AF2, and AF2 reduced 43.59% emission of CO2, 59.09% emission of SO2, 71% consumption of mineral resources, and 46.67% consumption of fossil resources than that of AF1 respectively. As an environment-friendly accelerator, AF2 had a better application performance than traditional accelerator AF1. When the dosage of accelerators was 7%, the initial setting times of cement pastes containing AF1 and AF2 were 4 min 57 s and 4 min 04 s respectively, the final setting times of cement pastes containing AF1 and AF2 were 11 min 49 s and 9 min 53 s respectively, and the compressive strengths at 1 d of mortars containing AF1 and AF2 were 7.35 MPa and 8.33 MPa respectively. This study aims to provide technical feasibility and environmental impact assessment for exploring new avenues of preparing environment-friendly liquid alkali-free accelerators with aluminum mud solid wastes. It has great potential in reducing carbon and pollution emissions and has a greater competitive advantage due to great application performance. [ABSTRACT FROM AUTHOR]

The combined utilization of mineral accelerators and nano-seeding materials is a novel method to promote the early strength of cement-based materials. In this paper, the effects of nano-C-S-H seed (NCS) on the early compressive strength of the Portland cement (PC)– calcium sulfoaluminate cement (CSA) binder were investigated. The results showed that NCS and CSA synergistically contributed to the early strength of PC. In detail, a 326.3% increase in the 10 h compressive strength of PC paste was obtained through the addition of NCS (2 wt%) and CSA (5%) in common. This was higher than the sum of the increases observed with the single additions of CSA (157.9%) or NCS (87.6%), with the same above dosage, in PC. Meanwhile, the early strength enhancement effects of NCS and CSA, when used together in PC, lasted longer than the effects of either used alone. Moreover, the synergetic effect mechanism was analyzed by isothermal calorimeter, QXRD, TGA, MIP, and SEM techniques. The calorimetry, XRD, and TGA results demonstrated that the synergistic mechanism was associated with the synergistic promotion effects of CSA and NCS on the hydrates. The fast hydration of CSA produced large amounts of ettringite and also consumed partial free water to promote the performance of the seeding effect of NCS which, simultaneously, further accelerated the precipitation of C-S-H gel and CH. The high alkie environment was also beneficial for the continuous generation of ettringite. In addition, the results of MIP and SEM measurements showed that the micro-filling effect of NCS significantly optimized the pore structure of a PC-CSA blend-hardened paste. Thus, the synergistic strength enhancement effects of CSA and NCS on PC were attributed to the matching of the promotion of hydration generation and the optimization of pore structures in hardening cement paste. The results of this article provide a new approach to achieving the rapid development of the early strength of cementitious materials, with potential applications in precast concrete and low-temperature construction. [ABSTRACT FROM AUTHOR]

Contamination of leafy vegetables grown in heavy metal(loid)-polluted mining areas pose serious health risks. This study aimed to explore the heavy metal(loid) contamination of leafy vegetables near two mining areas, by collecting samples from 14 different leafy vegetable species in Yunnan Province, China. The lead (Pb), cadmium (Cd), arsenic (As), and copper (Cu) contents of the samples were determined, and risks to human health were calculated using the hazard quotient and hazard index (HI). Moreover, Malabar spinach was identified as a leafy vegetable that exhibits low accumulation of heavy metal(loid)s. The accumulation capacity of different Malabar spinach varieties was verified, and a Cd soil safety threshold was determined using a pot experiment. Overall, Pb and Cd were the main soil and vegetable contaminants found in both study sites. The HI values for all leafy vegetables, apart from Malabar spinach, were greater than 1, indicating the presence of risks to human health; moreover, the health risks were greater for children than adults. The Malabar spinach pot experiment results showed that only some Cd forms exceeded China's maximum permissible standards. Furthermore, Malabar spinach varieties A (instant Malabar spinach), C (extra-large leaf green vine Malabar spinach), and F (large leaf Malabar spinach) displayed the lowest Cd accumulation. We calculated Cd total and bioavailable soil safety thresholds of 4.75 and 0.77 mg kg-1, respectively. However, further research is required to validate soil heavy metal safety thresholds for different vegetables. Ultimately, the heavy metal(loid) contamination of leafy vegetables described here was more serious than anticipated. Finally, the results of this study can inform residents living near these mining areas of a low-risk leafy vegetable, which will reduce the harm caused by heavy metal(loid) contamination in the area. [ABSTRACT FROM AUTHOR]

Concrete cracking has a negative impact on the durability of the structure. Pre-implanting microcapsules containing healing agents into the concrete are expected to induce the cracks to self-heal. However, the self-healing effect can potentially be influenced by several environmental conditions, thus limiting its applications. To address these challenges, we developed a new type of water-absorbing microcapsules, using calcium alginate hydrogel as the wall material and an adhesive epoxy polymer as the core material, to improve the self-healing adaptability in complex and changing environments. We explored the healing properties and mechanism of cementitious materials containing microcapsules under various environmental conditions. The experimental results showed that the water-absorbent microcapsules exhibit multiple self-healing effects under different external conditions: (1) in an anhydrous environment, fissures prompted the activation of microcapsules, and the epoxy polymer flowed out to seal the cracks. (2) When exposed to water, the microcapsules inflated to form a seal around the fissures. (3) The microcapsules facilitated the autogenous healing of cracks in the cementitious material when wet and dry conditions were alternated. The three self-healing mechanisms worked synergistically and contributed to the effective restoration of the impermeability and strength of concrete under different environments. Particularly, the recovery of compressive strength and impermeability exceeded 100% when the microcapsule content was 4% and the pre-pressure was 40% of fmax. [ABSTRACT FROM AUTHOR]

Ca(OH)2, a widely available and low-cost calcium-based desulfurizer, needs further improvement in calcium utilization in flue gas desulfurization. In this experiment, Ca(OH)2 crystals with different morphologies were prepared by doping impurity ions including SO42− and SiO32− by precipitation method, which played directing role in the process of crystal growth. The prepared Ca(OH)2 crystals were applied to cement kiln flue gas desulfurization environment to investigate the effect of crystal morphology on flue gas desulfurization. The observed results illustrated that Ca(OH)2 prepared by SO42− as impurity ion in hexagonal plate shape presents the best desulfurization performance with desulfurization efficiency up to 93%. The structural characterization of Ca(OH)2 crystals by XRD and SEM, and the investigation of the reasons for desulfurization by BET, EDS, and XPS showed that the hexagonal plate-shaped Ca(OH)2 crystals increased the specific surface area and had the highest elemental sulfur content of 5.04% on the (100) crystal plane, and the high surface energy on the (100) plane led to the high reactivity. This confirms the guiding significance of hexagonal plate-like morphology for improving the desulfurization performance of Ca(OH)2. [ABSTRACT FROM AUTHOR]

Polycarboxylate ether (PCE) superplasticizers are widely used in concrete, but in some cases, PCE aggravates the occurrence of cracks. This study evaluates the shrinkage reduction and plasticizing properties of a newly synthesized shrink-reducing polycarboxylate polymer (KH-SRPC) modified with ester and silane groups. When the KH-SRPC was implemented at a dosage of 0.3% by weight of cement, the adsorption capacity on the surface of the cement particles and the spreading diameter of the cement improved with respect to traditional PCE. Furthermore, the autogenous shrinkage and drying shrinkage of the mortar containing KH-SRPC were also investigated. When the KH-SRPC content was 0.2% of the weight of the cementitious material, the autogenous shrinkage of the KH-SRPC mortars at 3 and 7 days was reduced by 72.6% and 43.5%, respectively. The drying shrinkage of KH-SRPC mortars decreased by 38.3% at 3 days, 39.0% at 7 days, 39.1% at 14 days, and 35.7% at 28 days. It was found that KH-SRPC changed the pore structure of the solidified mortar, reduced the surface tension of the pore solution, and slowed down the rate of hydration, thereby reducing the total shrinkage of the mortar system. [ABSTRACT FROM AUTHOR]

Reducing or eliminating cracks caused by shrinkage of cementitious materials remains a daunting challenge for construction engineers. Drying shrinkage and autogenous shrinkage are the main shrinkage types in the service process of cement-based materials, which have a great impact on engineering applications. If cracks in concrete generate by drying or autogenous shrinkage, the mechanical properties, water resistance and durability of concrete will be also affected. It is an effective method to use chemical admixtures to inhibit the shrinkage of cement-based materials. Polycarboxylate plasticizer (PCE) is an important chemical admixture in cement-based materials and is widely used in practical engineering. It can bring great value by reducing the shrinkage effect through molecular design. Through our innovative design, a series of shrinkage-reducing polycarboxylate superplasticizers (SRPs) were synthesized, their molecular structures were confirmed by Fourier transform infrared spectroscopy (FTIR) and their molecular properties were determined by gel permeation chromatography (GPC). Furthermore, the shrinkage performances at different ages of the mortars containing the synthesized SRPs with different structures were systematically evaluated. The results showed that compared with the blank sample, the dry shrinkage rate and free shrinkage rate of the mortars containing SRP decreased by over 20% and 15%, respectively. Additionally, the shrinkage rates of the mortars containing SRP were significantly lower than that of the mortar containing conventional PCE, and moreover, the water-reducing performance was improved compared to conventional PCE. Based on the experimental results of surface tension and evaporation rate of different SRP solutions, the mechanism of the shrinkage-reducing effect was probed, as expected to provide guidance for the design and development of new shrinkage-reducing admixtures. [ABSTRACT FROM AUTHOR]

This study explored the effects of contributing factors on crash frequency, by injury severity of all, daytime, and nighttime crashes that occurred on freeways. With three injury severity outcomes classified as light injury, minor injury, and severe injury, the effects of the explanatory variables affecting the crash frequency were examined in terms of the crash, traffic, speed, geometric, and sight characteristics. Regarding the model estimations, the lowest AIC and BIC values (2263.87 and 2379.22, respectively) showed the superiority of the random-parameter multivariate negative binomial (RPMNB) model in terms of the goodness-of-fit measure. Additionally, the RPMNB model indicated the highest R2 (0.25) and predictive accuracy, along with a significantly positive α parameter. Moreover, transferability tests were conducted to confirm the rationality of separating the daytime and nighttime crashes. Based on the RPMNB models, several explanatory variables were observed to exhibit relatively stable effects whereas other variables presented obvious variations. This study can be of certain value in guiding highway design and policies and developing effective safety countermeasures. [ABSTRACT FROM AUTHOR]

The wide application of surfactants in cement-based materials requires the understanding of the influence of surfactants on the structure and properties of C–S–H gel. In this study, cation surfactants (CTAB) and anion surfactants (SDS) in ionized type are successfully intercalated into C–S–H gel, generating different molecular models through molecular dynamics simulation. Systematic analysis and quantitative description were performed on the molecular structures, bonding properties together with deformation and fracture mechanisms. It was found that the majority of Br– ionized from CTAB could interact with Ca_interl, forming Br-−Ca_interl bonds. Smaller Na+ ionized from SDS could bond with both O_bri and O_nbri atoms, while O– and O atoms in SDS anions could interact with Ca_interl atoms as well. It is noteworthy that the intercalation of CTAB into C–S–H gel promotes the diffusion of water molecules, whereas the intercalation of SDS into C–S–H gel inhibits the diffusion of water molecules. Uniaxial tensile simulation results reveal that the breakage of both H_water–O_water hydrogen bonds and Ca_interl–O_water bonds dominates the failure process of CTAB/C–S–H gel, while the breakage of H_water–O_water hydrogen bonds governs the fracture of SDS/C–S–H gel. [ABSTRACT FROM AUTHOR]

Background: Triple‐negative breast cancer (TNBC) is a common hypotype of breast cancer. Circular RNAs (circRNAs) are burgeoning serve as vital controllers in numerous tumors. Nevertheless, the expression and regulatory mode of circRNAs in TNBC are still indistinct. This paper aimed to reveal the function and molecular mechanism of circular RNA dehydrodolichyl diphosphate synthase (circDHDDS) in TNBC. Methods: The contents of circDHDDS, DHDDS mRNA, microRNA‐362‐3p (miR‐362‐3p) and DEAD (Asp‐Glu‐Ala‐Asp) box polypeptide 5 (DDX5) were indicated by quantitative real‐time polymerase chain reaction (qRT‐PCR) and western blot. The colony formation assay and 5‐ethynyl‐2'‐deoxyuridine (EdU) assay were executed to assess cell proliferation. The flow cytometry assay was utilized to detect cell apoptosis. The transwell assay and tube formation assay were applied to measure cell migration, invasion and angiogenesis. The targeted relationships of miR‐362‐3p and circDHDDS or DDX5 were forecasted and detected by dual‐luciferase reporter assay. The in vivo test was implemented to confirm the effect of circDHDDS. Results: The contents of circDHDDS and DDX5 were increased, and miR‐362‐3p level was decreased in TNBC. CircDHDDS deficiency reserved cell proliferation, migration, invasion and angiogenesis, while facilitated cell apoptosis in TNBC cells. Furthermore, miR‐362‐3p was validated to exert a tumor repressive effect in TNBC cells by suppressing DDX5. Moreover, DDX5 could regulate the development of TNBC. The experimental data exposed that levels of miR‐362‐3p presented noteworthy negative correlation with circDHDDS and DDX5, while circDHDDS and DDX5 exhibited significant positive correlation. In mechanism, circDHDDS bound to miR‐362‐3p to modulate DDX5 expression. In addition, circDHDDS knock‐down also attenuated tumor growth. Conclusion: CircDHDDS expedited TNBC by swelling DDX5 via adapting miR‐362‐3p. [ABSTRACT FROM AUTHOR]

The wildly‐used charring agent, pentaerythritol (PER), was solely incorporated into polyamide 11 (PA 11) matrix by melt compounding. The addition of 15%PER improved the UL rating of PA 11‐PER composites to V‐0 and reduced the peak heat release rate by 22.1%. Most importantly, the time to ignition had been incredibly increased from 93 s of neat PA 11 to 193 s of PA 11‐15PER sample. The thermal behaviors were investigated by thermogravimetric analysis (TGA) and TGA‐Fourier transform infrared (FTIR). The morphology, chemical structure and physical properties (such as crystallinity and viscosity) of char residues that were collected at ignition point or after MLC tests of PA 11 and PA 11‐15PER composites were fully demonstrated. It was suggested that the interactions between PA 11 and PER led to the rapid formation of a compact char layer which exhibited sufficient viscosity before ignition in the condensed phase, while the early released H2O and CO2 from PER took effects in the gas phase. [ABSTRACT FROM AUTHOR]

The application of cement-based materials in engineering requires the understanding of their characteristics and subsequent deformation and fracture process of C–S–H gel in service. In this work, three types of amine molecules including tetraethylenepentamine (TEPA), polyacrylamide (PAM), and triethanolamine (TEA) were intercalated into C–S–H gel in an unsaturated status successfully. Systematical analysis was performed on the structures and properties for both C–S–H gel and corresponding amine molecules/C–S–H gel. It was found that the unsaturated intercalation of amine molecules into C–S–H gel plays a key role in the geometry and therein density of nanocomposites. Subsequently, radial distribution function (RDF), time-correlated function (TCF), and mean square displacement (MSD) were applied to characterize the structure and dynamic information of the as-generated nanocomposites, demonstrating the occurrence of interaction between amine molecules with Ca–Si layer and acceleration of water diffusion by unsaturated intercalation of amine molecules into the interlayer region in C–S–H gel. Finally, the deformation and fracture process of C–S–H gel and amine molecules/C–S–H gel under uniaxial tensile loads were given by molecular dynamics simulation. It was indicated that the tangent modulus of nanocomposites demonstrates a strain-softening nature, indicating a visco-elastic behavior. The breakage of Ca–O bonds and hydrogen bonds dominates the fracture of C–S–H gel. Weak interaction for TEPA/C–S–H gel or TEA/C–S–H gel leads to a decreased tensile strength. Local stress concentration in other interlayer region governs the deformation and fracture process in spite of the formation of strong interaction between double bonded polar oxygen atoms in PAM molecules and Ca atoms in C–S–H gel. [ABSTRACT FROM AUTHOR]

In this study, a polyphosphate superplasticizer (PPE) used in sulphoaluminate cement was synthesized by using un-saturated phosphate ester as monomer. The effects of molecular structures of polyphosphate superplasticizer on the fluidity of sulphoaluminate cement paste were investigated. When n (HPEG) :n (MOEP) :n (TGA) :n (APS) was 1:4:0.2:0.1, the effect of PPE on the fluidity and fluidity retention of sulphoaluminate cement is better compared to ordinary polycarboxylate superplasticizer (PCE). The mechanism of polyphosphate superplasticizer was probed in detail by X-ray photoelectron spectroscopy (XPS). The results showed that after adding 1% polyphosphate superplasticizer, the peaks of Ca2p and Al2p of sulphoaluminate cement shifted 0.173 eV and 0.175 eV respectively, which were greater than those of ordinary polycarboxylate superplasticizer. Accordingly, this new type of polyphosphate superplasticizer synthesized by us can play its role in dispersing sulphoaluminate cement particles via strong chemisorption on their surfaces. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate how the addition of shrinkage-reducing polycarboxylate superplasticiser (SRPC) affected the shrinkage of cement-based materials (CBMs). SRPCs can significantly reduce the surface tension of cement solutions. In this work, a new molecular structure of SRPC was synthesised; its surface tension was reduced to 34·1 mN/m, which is lower than that of ordinary polycarboxylate superplasticisers (PCEs). Compared with mortars without additives, the shrinkage-reducing ratios of mortars containing SRPC at 7 and 49 d were about 33 and 22%, respectively, for an SRPC dosage of 0·2% by mass of cement. The results showed that the SRPC reduced the shrinkage of CBMs more effectively than an ordinary PCE. Furthermore, the shrinkage mechanism of CBMs containing SRPC was assessed regarding three aspects: the change in the pore size distribution of the cement pastes with pore size below 50 nm, the reduction of the capillary pore pressure in the hardened cement pastes after the addition of a low-surface-tension SRPC and the reduction in the evaporation rate of moisture through SRPC aggregation on the gas–liquid interface in cement pastes. [ABSTRACT FROM AUTHOR]

Biomass char is accepted as an environmentally friendly energy resource, and is promising for NO removal in industrial furnaces. NO reduction with biomass char (rice husk) was investigated in a fixed-bed quartz reactor. The influence of CO concentration, reaction temperature, initial NO concentration, and char loading on the NO reduction were evaluated. The results showed that the overall NO reduction reaction was dominated by the direct reaction of NO with char without CO. Increasing CO concentration resulted in an enhanced catalytic reaction between NO and CO over the char surface and a decreased carbon consumption of char. With decreasing temperature, the influence of CO concentration on NO reduction was strengthened. Over the test temperature range, char provided a surface to catalyze the NO–CO reaction at excess CO/NO ratio. Increasing the initial NO concentration led to an increasingly significant influence on NO reduction with the enhanced CO/NO ratio. With increased char loading, the enhancement of NO reduction became unobservable for excess CO/NO ratio. Reaction orders of NO and activation energy for NO reduction by char were 0.71 and 60.21 kJ·mol−1, respectively, against 0.82 and 34.60 kJ·mol−1, respectively, for NO reduction by CO, catalyzed by char. [ABSTRACT FROM AUTHOR]

This study aims to analyze the effect of high-altitude environment on drivers' mental workload (MW), situation awareness (SA), and driving behaviour (DB), and to explore the relationship among those driving performances. Based on a survey, the data of 356 lowlanders engaging in driving activities at Tibetan Plateau (high-altitude group) and 341 lowlanders engaging in driving activities at low altitudes (low-altitude group) were compared and analyzed. The results suggest that the differences between the two groups are noteworthy. Mental workload of high-altitude group is significantly higher than that of low-altitude group, and their situation awareness is lower significantly. The possibility of risky driving behaviours for high-altitude group, especially aggressive violations, is higher. For the high-altitude group, the increase of mental workload can lead to an increase on aggressive violations, and the situation understanding plays a full mediating effect between mental workload and aggressive violations. Measures aiming at the improvement of situation awareness and the reduction of mental workload can effectively reduce the driving risk from high-altitude environment for lowlanders. [ABSTRACT FROM AUTHOR]

A blended cementitious material consisting of cement and titanium slag in a mass ratio of 1:1 was prepared and the influence of varying dosages of tetrakis (2-hydroxyethyl) ethylenediamine (Theed) on the strength development and hydration process of the blended systems was investigated. The hydration process, pore structure and microstructure at different ages were characterised by isothermal conduction calorimetry, X-ray diffraction, thermogravimetric analysis, mercury intrusion porosimetry and scanning electron microscopy. The results showed that: the addition of Theed (0·01–0·10%) tended to improve the flexural and compressive strength of the blended mortars; the addition of Theed increased the hydration degree of the blended cement pastes before 28 d while delaying the early (before 6 h) hydration, as indicated by isothermal calorimetry measurement; the pore structure of the blended cement pastes after curing for 28 d was modified by Theed, which is beneficial for strength development; the pozzolanic reaction of the titanium slag was enhanced by the presence of Theed, as confirmed by the portlandite content, pore structure measurements and morphological observation. [ABSTRACT FROM AUTHOR]

Purpose: The purposes of this study were to quantify the resource consumption intensity of cement clinker production using natural mineral in China and to determine the influence of the utilization of calcium carbide sludge (CCS) for cement clinker production on the resource-accounting result. Methods: Exergy-based resource accounting method was adopted by this study. Cumulative exergy demand (CExD) was used to characterize the resource consumption intensity of cement clinker production using natural mineral in China. Exergy-based characterization factors of land resource and CO2 emission were employed to determine the resource benefit brought by the substitution of CCS for natural limestone (land saving and CO2 reduction). Results and discussion: The CExD value of cement clinker production using natural mineral as raw material in China is 5005 MJ/t, and the consumption of raw coal is the largest contributor to this result, accounting for approximately 81% of the CExD value. The phenomenon that coal consumption dominates the CExD result may be because, through combustion reactions, the chemical state of carbon contained in coal almost reaches equilibrium with its chemical dead state in terms of exergy and is deeply dissipated; in comparison, the major chemical compound contained in limestone, i.e., calcium oxide, is mostly transformed into cement clinker by the reactions occurred in the production system, instead of being consumed in a deeply dissipated way and emitted to the environment. The major disadvantage of using CCS for cement clinker production is the increase of coal consumption, i.e., 515 MJ/t cement clinker, and the major advantage of using CCS for cement clinker production is the resource benefit brought by CO2 reduction (the avoided biotic resource damage in ecosystem), i.e., 1160 MJ/t cement clinker. Conclusions: From the analysis on the influence of the substitution of CCS for limestone on the resource consumption intensity, we found that the resource consumption intensity of the production system using CCS is approximately 15.5% lower than that of the production system using natural mineral; however, if this resource benefit is neglected, the resource consumption intensity of the production system using CCS is approximately 7.6% higher than that of the production system using natural mineral. We suggest that establishing a theoretical bridge between the characterization models of biotic resource and abiotic resource will still be a significant research direction in the future, which is fundamental in objectively understanding and unifying the issues of emission reduction and resource saving. [ABSTRACT FROM AUTHOR]

Biochar materials are good reducers of nitrogen oxides. The composition and structure of biochar affect significantly its ability to reduce C–NO. In order to study the denitration of flue gases by biochar at high temperature, three kinds of biochar (bamboo charcoal (BC), rice husk ash (RHA), and straw charcoal (SC)) were mixed with cement raw meal in a fixed-bed quartz reactor at the temperature of 800–900 °C and O2 concentration of 0.5%–2%. The results showed that the initial denitration rate of BC was higher than that of RHA, and that of SC was the lowest. RHA had the largest specific surface area, and BC the smallest. The elements C, N, and O and the functional groups of the three types of biochar had a greater influence on the denitration rate than their structures. The denitration rate decreased faster as the O/C ratio increased, and the increase in the relative content of the N element induced the formation of nitrogen-containing functional groups catalyzing C–NO reduction. The content of the C–C bond affected directly the rate of denitration, and both (NCO)x and C–O bonds had a positive effect on the reduction capability of biochar. It can be concluded that the composition of biochar has an important effect on the reduction of C–NO. [ABSTRACT FROM AUTHOR]

To improve the utilization of crop straws as a resource and the compatibility between straw fibers and cement-based materials, the hydration of modified straw fiber cement-based composite (SFCC) was studied. The structural characteristic of SFCC was investigated by FTIR, SEM, and XRD. The results show that the setting time of several modified straw fiber SFCC pastes was shorter than that of the unmodified straw fiber SFCC paste, and the best method of fiber modification to improve the setting time of the SFCC paste is Na2O·nSiO2 treatment. The recommended fiber modification method for improving the compatibility between straw fibers and cement-based materials is alkali modification, followed by pure acrylic emulsion modification and Na2O·nSiO2 modification. To improve the strength of SFCC, the straw fiber should be modified by alkali, followed by pure acrylic emulsion and Na2O·nSiO2 modification and the method of water modification is also recommended. The phase types and relative contents of crystalline hydration products mixed with the modified straw fiber SFCC are significantly higher than those of the unmodified fiber SFCC. The fiber treatment method that was most helpful to increase the structural density of hydrates of SFCC was alkali treatment and pure acrylic emulsion treatment, followed by Na2O·nSiO2 treatment. [ABSTRACT FROM AUTHOR]

In this work, a novel sulfur‐based flame retardant (SA‐M) was synthesized by the self‐assembly of melamine and sulfamic acid. The chemical structure of SA‐M was fully characterized. SA‐M, in company with Al2O3, was then introduced into polyamide 11 (PA 11) by melt compounding in order to improve the fire resistance of the polymer substrate. The observation by scanning electron microscopy (SEM) and electron probe microanalysis (EPMA) indicated the well dispersion of SA‐M in PA 11 matrix. The fire performance of PA 11 composites was evaluated by limiting oxygen index (LOI), vertical burning (UL‐94), and cone calorimeter tests, respectively. The results showed that the presence of 17.5% SA‐M and 2.5% Al2O3 increased the LOI value from 22.4% to 30.9%, upgraded the UL‐94 rating from no rating to V‐0, significantly eliminated the melt dripping, and decreased the peak heat release rate from 1024 to 603 kW/m2. The thermal behaviors were investigated by thermogravimeric analysis (TGA) and TGA‐Fourier transform infrared spectroscopy (FTIR). It was suggested that SA‐M took effects mainly in gas phase by diluting the combustible fuel, leading to the improvement of the fire resistance of PA 11. [ABSTRACT FROM AUTHOR]

The isothermal absorption properties and kinetic model of Cr (VI) and Cr (III) onto ettringite were investigated using the batch adsorption method. IR analysis was used to study the difference and mechanism of the adsorption of chromium ions with different valence states. The results show that the adsorption of Cr(III) onto ettringite at 20 °C agrees with Langmuir's isothermal model. The ion binding stability was significantly greater than that of Cr (VI). While the adsorption of Cr(VI) onto ettringite agrees with Freundlich's isothermal model, the D-R model fits the adsorption isotherms of two types of valence Cr (R2> O.994). It can be concluded that the adsorption of Cr (III) onto ettringite is mainly by chemical adsorption and that the adsorption of Cr (VI) onto ettringite is mainly by physical adsorption. Dynamic model fitting and model parameter analyses show that the adsorption of Cr (III) onto ettringite agrees with the pseudo second order kinetics model given by Lagergren. The formation of chemical bonds is the main factor causing the fast adsorption. Cr (VI) adsorption is mainly dominated by liquid film diffusion, and the adsorption rate is much slower than that of Cr (III) adsorption. [ABSTRACT FROM AUTHOR]

The commercial fluorocarbon surfactant (FCS) DuPont™ Zonyl 321 fluorinated cationic surfactants, was employed to modify both flat‐sheet and hollow‐fiber poly(tetrafluoroethylene) (PTFE) porous membranes. The variation of morphology, wettability, and hydrophilicity durability to acid and alkali as well as the filtration performance of both membranes were investigated. Such superhydrophilic membranes showed better wetting stability and higher resistance to acid and alkali solutions. Moreover, both membranes exhibited good filtration performance. [ABSTRACT FROM AUTHOR]

Compressive stress and tensile stress were applied to concrete specimens using test rigs designed by RILEM TC 246-TDC. Ultrasonic wave velocity and autoclam permeability system were used to characterize the damage variable and gas permeability coefficient of concrete, respectively. The experimental results show that the strain value of concrete increases with the increasing of stress level and loading time. The damage variable and gas permeability coefficient of concrete under compressive stress decrease at first and increase after a threshold value between 0 and 0.6. When the concrete is under tensile load, the damage variable and gas permeability coefficient increase with tensile stress, with a significant increase from 0.3 to 0.6 tensile stress. There is a strong linear relationship between the damage variable and the gas permeability coefficient, suggesting both as good indicators to characterize the damage of concrete under stress. [ABSTRACT FROM AUTHOR]

Urea formaldehyde/epoxy resin microcapsules were prepared by an in situ polymerization method and the effect of emulsifier on the syntheses process of the microcapsules was discussed. The surface morphology of the microcapsules was observed by optical microscopy and scanning electron microscopy (SEM). Chemical structure was characterized by Fourier transform infrared spectroscopy (FTIR). Thermal stability was obtained using simultaneous thermal analysis (STA). The microcapsules were composed of urea-formaldehyde resin shell and epoxy resin core. Emulsifier played an important role in the polymerization process when the core material was packed by pre-polymer, so the effects of different emulsifiers (OP-10, SDS and SDBS) were discussed respectively. Results showed that the particle size of the microcapsules was uniform when SDBS as an emulsifier. Microcapsules showed good thermal stability below 240 °C and the initial decomposition temperature of the microcapsules was 265 °C. The core materials released after microcapsules rupturing, which could be proven by the images of SEM. When implanted in cementitious composites, complete shape of microcapsules and good interface between microcapsules and cement specimen substrate could also be observed. [ABSTRACT FROM AUTHOR]

In this study, the effect of CO2 concentration on carbonation depth, semi-carbonated zone, pore size distribution and carbonation products in concrete were investigated. The CO2 concentration was increased from 0.035 % to 2 % and 20 % at 70 % relative humidity and 20 °C. The results show that the carbonation process of 2 % CO2 was more similar to natural carbonation than 20 % CO2, as evidenced by the better linearity fitness of carbonation depth. The length of semi-carbonated zone was 6 mm at 2 % CO2 and 8 mm at 20 % CO2 within 16 weeks, a number that cannot be ignored when predicting the service life of concrete under carbonation. CH remained in a small amount in the completely carbonated zone instead of being completely consumed, and CH consumed at 20 % CO2 is about 1.5-2.0 times that of 2 % CO2. The content of CaCO3 in the completely carbonated zone at 20 % CO2 was higher than that of 2 % CO2. CaCO3 could fill in large pores between hydration products, so the porosity, average pore size and aperture decreased with CO2 concentration. [ABSTRACT FROM AUTHOR]

Mn-Ni/TiO2catalysts were prepared using a joint precipitation method with acid-dissolved titanium slag as raw material for selective catalytic reduction of nitrogen oxide. The joint precipitation method was accomplished with different precipitants, such as sodium hydroxide, carbamide, ammonia, or hydrogen peroxide. The deNOx activities of the catalysts prepared by different precipitants were investigated with SCR activity reactor within temperatures of 90–350°C. It is evident that the Mn-Ni/TiO2catalyst with carbamide-ammonia-hydrogen peroxide as precipitant has superior catalytic activity, which the NO conversion can reach 90% at 120°C, with a wider temperature window (120–300°C) for the NH3-SCR reaction. H2-TPR results showed that the reduction potential of MnOx species on Mn-Ni/TiO2catalysts is increased compared to that of Mn/TiO2catalysts. Oxygen mobility is enhanced by interaction between Ni and Mn atoms due to use of carbamide-ammonia peroxide as precipitant. XPS results suggest that the presence of MnO2is the major phase in nickel-doped Mn/TiO2catalysts. Our NH3-TPD results illustrated that the catalysts have a lot of acid-active sites, which lead to attracting more ammonia to participate in the catalytic reaction. [ABSTRACT FROM AUTHOR]

Purpose: Cement production is associated with a considerable environmental load, which needs to be fully understood before effective measures can be taken. The existing literature did not give detailed life cycle assessment (LCA) study of China and had limited potential for investigating how best available techniques (BATs) would provide a maximum benefit when they are applied in China. Japan was selected as a good example to achieve better environmental performance of cement production. We identified potentials for reducing emissions and saving energy and natural resources in Chinese cement industry through the comparative analysis. Methods: This paper follows the principal of Life Cycle Assessment and International Reference Life Cycle Data System ( ILCD). The functional units are '1 t of portland cement' and with 42.5 MPa of strength grade. The input (limestone, sandstone, ferrous tailings, coal, and electricity) and output (CO from limestone decomposition and coal combustion, NOx, PM, and SO) of cement manufacturing were calculated by use of on-site measurements, calculation by estimated coefficients, and derivation by mass and heat balance principle. The direct (cement manufacturing) and indirect (electricity production) LCI are added to be total LCI results (cement production). The impact categories of global warming potential (GWP), acidification potential (AP), eutrophication potential (EP), photochemical oxidant formation potential (POCP), and human toxicity potential (HTP) are used to calculate environmental impact. Results and discussion: Only in GWP of cement manufacturing China has advantage. Japanese cement industry shows remarkable superiorities in the environmental impacts of AP, POCP, HTP, and EP due to advanced technologies. SO emissions make the corresponding AP and HTP. PM emissions result in part of HTP. The NOx emissions are the major contributors of POCP, AP, EP, and HTP in China. China emits fewer CO emissions (2.09 %) in cement manufacturing than Japan but finally makes higher total GWP than Japan due to more GWP of electricity generation in power stations. The waste heat recovery technology can save electricity but bring more coal use and CO emissions. The alternative fuel and raw materials usage and denitration and de-dust technologies can relieve the environmental load. Using the functional unit with the strength grade, the life cycle impact assessment (LCIA) results are affected. Conclusions: LCA study allows a clear understanding from the view of total environmental impact rather than by the gross domestic product (GDP) unit from an economic development perspective. In an LCA study, the power generation should be considered in the life cycle of cement production. [ABSTRACT FROM AUTHOR]

The traditional alumina-silicate raw materials, for example, clays, in the precalcining technique of cement production, have been replaced by low grade and high silica content sandstones, shales, and industrial waste residues, including fly ashes, slag, and others. The results are the change of compositions and characteristics of raw materials applied and a great effect on cement calcination process and clinker formation. In this work, the cement clinker formation process of different alumina-silicate raw materials to replace clay raw material was studied by chemical analysis, X-ray diffraction, differential thermal analysis, and high temperature microscope based on the characteristics of the alumina-silicate raw materials. The formation heat of the clinker was determined by the acid dissolution method. Influence of different alumina-silicate raw materials on the clinker burnability and formation process was studied. The results show that the changing of alumina-silicate raw materials, especially using industrial waste residues, can reduce the formation temperature of high temperature liquid phases, improve the burnability of raw materials, reduce the formation temperature and formation heat of clinker. And this study also observed the formation temperature and transformation of high temperature liquid phases in the heating process of raw materials by high temperature microscope. [ABSTRACT FROM AUTHOR]

Sodium lignosulfonate (SL), a byproduct of the pulping industry, was used as a stabilizer for the mineralization of CaCO3. In a calcium acetate-urea-water system, the direct aging of the aqueous solution of calcium acetate and urea resulted in the formation of mixed aragonite and vaterite phases or a pure aragonite phase depending on the aging time. However, SL was introduced into the calcium acetate-urea-water system to markedly stabilize the formation of a thermodynamically unstable vaterite phase. Various morphologies of vaterite structures were observed by adjusting the concentration of urea and SL as well as the aging time. Based on these results, ion exchange, carbonate attacking the calcium(II) ions, aggregations of SL-stabilized primary CaCO3 particles through oriented attachment and Ostwald ripening, as well as mesoscale self-assembly were proposed as mechanisms to elucidate the formation of various morphologies. [ABSTRACT FROM AUTHOR]

Self-healing cementitious materials are a promising means for ensuring sustainable concrete infrastructure and promoting long-term service lives. To obtain microcapsules that are versatile in varying environments, in this study, absorbing microcapsules with calcium alginate as the shell and epoxy resin as the core were prepared. The absorbing microcapsules exhibit self-healing and can reduce the shrinkage of cementitious materials. Volume changes of the microcapsules in the hardened paste with increasing hydration age were observed using three-dimensional X-ray computed tomography. In the hardened cement paste with a water-cement ratio of 0.29, the absorption of the microcapsules lasted for several days, and the release of water lasted for 28 days. The absorption of microcapsules affected the fluidity of cement paste, and it was significantly weakened and delayed due to the lower absorption rate. The addition of absorbing microcapsules significantly reduced the autogenous and drying shrinkage of mortars. For microcapsules with a core content of 55% added at 3.5% of cement weight, autogenous shrinkage was almost eliminated. Most importantly, the addition of absorbing microcapsules could achieve a certain degree of recovery of compressive strength as well as satisfactory recovery of impermeability in dry and wet environments. [ABSTRACT FROM AUTHOR]

This study is based on the three types of residential buildings with framework structures in Beijing: concrete framework construction (CFC), light-gauge steel framework construction (SFC), and wood framework construction (WFC). The analysis of the environmental load across the life cycle of the three types of buildings is conducted using life cycle assessment (LCA) according to the protocols of the International Organization for Standardization (ISO) 14040/44. The functional unit is the three material building designs, which possess the same function and design plan, and are built in concrete, light-gauge steel, and light frame wood, inclusive of their respective envelope materials. Throughout the investigation, the calculations of the environmental load data of materials, energy consumption, and carbon dioxide (CO2) emissions are comprehensively assessed and compared. The study shows that over the life cycle, the energy consumption of CFC is almost the same as that of SFC, and each of them is approximately 30% higher than that of WFC. Building use, steel material production, cement production, gypsum board production, and material transport are the main construction activities related to the energy consumption; the net CO2 emission of CFC is 44% higher than that of SFC and 49% higher than that of WFC. The main source of CO2 emission is the use of electricity; its contributions to the net CO2 emissions of WFC, SFC, and CFC are 67%, 64%, and 44%, respectively. The net CO2 emissions in the transport category cannot be ignored, with proportions amounting to 8%, 12%, and 11% for WFC, SFC, and CFC, respectively. [ABSTRACT FROM AUTHOR]

Abstract  β-1,3-Glucanases are a group of pathogenesis-related proteins that have been reported to be involved in plant defense against pathogens in many other plant-pathogen systems. However, it was not clear if these genes play similar role in wheat (Triticum aestivum L.) against Puccinia striiformis f. sp. tritici (Pst), the stripe rust pathogen. To investigate the role of β-1,3-glucanase (EC 3.2.1.39) in the resistance response of wheat (cv. Suwon 11) to stripe rust, a wheat β-1,3-glucanase gene induced by Pst, designated as TaGlu, was cloned and characterized. TaGlu was predicted to encode a basic protein of 334 amino acids. Quantitative real-time PCR analyses revealed that the transcription of TaGlu was induced during both compatible and incompatible interactions with Pst, but the transcription level was much higher in the incompatible interaction than that in the compatible interaction. TaGlu also showed noticeable induction of gene expression in young green leaf tissues treated with salicylic acid, methyl jasmonate or ethylene. Immunogold labeling assays showed that the enzyme were localized mainly in the host cell wall and over the extrahaustorial matrix, and the labeling densities were found significantly higher in the incompatible interaction than those in the compatible interaction. [ABSTRACT FROM AUTHOR]

In this work, a novel intumescent flame retardant (IFR) system was fabricated by the introduction of chitin as a green charring agent, ammonium polyphosphate (APP) as the acid source, and melamine (MEL) as the gas source. The obtained chitin-based IFR was then incorporated into a polylactic acid (PLA) matrix using melt compounding. The fire resistance of PLA/chitin composites was investigated via the limiting oxygen index (LOI), UL-94 vertical burning, and cone calorimeter (CONE) tests. The results demonstrated that the combination of 10%APP, 5%chitin and 5%MEL could result in a 26.0% LOI, a V-0 rating after UL and a 51.2% reduction in the peak heat release rate during the CONE test. Based on the mechanism analysis from both the morphology and the chemical structure of the char, it was suggested that chitin was a promising candidate as a charring agent for chitin reacted with APP and MEL with the formation of an intumescent layer on the surface. [ABSTRACT FROM AUTHOR]

The potential possibility of blast furnace slag as a low-cost adsorbent to remove lead ions from wastewater was investigated in detail in the present work. Both single factor experiment and orthogonal experiment were performed to reveal the effect of pH, adsorption temperature, contact time and initial concentration of lead ions on the adsorption performance of pristine slag. In order to make clear the correlation between the lead ion adsorption performance and the structure of slag, solid state nuclear magnetic resonance (NMR) was conducted to reveal the network structure and X-ray fluorescence (XRF) was used to calculate the nonbridging oxygen in the network-forming tetrahedra. For the purpose of improving the adsorption performance, γ-aminopropyltriethoxysilane (APTES) was adopted to modify the slag via post-grafting method. The results show that the slag is predominately composed of SiO2, Al2O3, CaO and MgO, exhibiting an amorphous network structure based on SiO4 and AlO4 tetrahedra. The conditions for adsorption can be optimized as follows: a pH of 7, an adsorption temperature of 60 °C, a contact time of 120 min and an initial lead ion concentration of 40 mg·L−1. Under the optimal conditions, a removal rate of 99.98% and an adsorption capacity of 49.99 mg·g−1 are obtained for the pristine slag. The adsorption complies with the Langmuir model thermodynamically and conforms to the pseudo-second order model kinetically. It is noted that aminopropyl-modification has considerably enhanced the removal rate of lead ions from 20.71 to 64.32% and the adsorption capacity from 29.01 to 96.48 mg·g−1 since amino groups (-NH2) are more inclined to form a complex with lead ions than hydroxyl groups due to the higher nucleophilicity of amino groups than that of hydroxyl groups. However, it is necessary to develop more low-cost modification agents in the future work. [ABSTRACT FROM AUTHOR]

The chemical structures of four types of superplasticizers (SPs) and their adsorptive behaviors on β-C2S were investigated. The adsorption properties of SPs on β-C2S were measured and the relationship between the adsorption quantity and the specific surface of β-C2S was analyzed. The experimental results show that the adsorption quantity increases with the surface area increase of β-C2S, but the adsorption quantity per surface area is similar, which means that the main adsorbent is β-C2S itself. Polycarboxylic ester (PCE) showed the highest adsorption amount on β-C2S, followed by β-naphthalene sulfonates (NSF) and formaldehyde-acetone condensates sulfonates (FAS), amino sulphonate (AS) showed the least adsorption amount on β-C2S. PCE affected the surface potential of β-C2S particles in water differently in comparison with other types of SPs. The adsorption capacity of SPs on β-C2S is determined by factors such as molecular structure, functional groups and molecular weight of SPs. [ABSTRACT FROM AUTHOR]

A series of novel comb-like poly(butyl acrylate)-g-poly(dimethylaminoethyl methacrylate) (PBA-g-PDMAEMA) with different side chain lengths were designed and successfully synthesized by the "first main chain then side chain" method. Infrared Spectroscopy (IR), 1H Nuclear Magnetic Resonance (1H NMR), and gel permeation chromatography (GPC) were used for structural confirmation and molecular weight characterization. This polymer exhibited responsive behavior from hydrophilicity to hydrophobicity under the alkaline environment of cement-based materials, with the contact angle of 105.6°, a decreased evaporation rate, and a hydrophile–lipophile balance (HLB) value. A significant internal hydrophobic effect on cement mortar was shown in the water absorption rate, which decreased by 75.2%, and a dry shrinkage-reducing rate of more than 30%. Furthermore, this polymer can effectively slow the exothermic rate, reduce the heat release, and delay the exothermic peak of cement hydration. It was interesting that these properties showed a direct correlation with the side chain length of the comb polymer. The aims of this study are to provide a new avenue to synthesize polymers with the spontaneous hydrophilicity–hydrophobicity transition in the cement system, achieving excellent internal hydrophobicity of cement-based materials, and to offer a promising alternative to resist external erosion for improving the durability and service life of cement-based materials. [ABSTRACT FROM AUTHOR]