Study on Road Performance of Cement Fly Ash Stabilized Steel Slag—Concrete Recycled Macadam

In order to promote the application of steel slag in road engineering, improve its utilization rate and solve the environmental problems caused by its large accumulation, unconfined compressive strength (UCS) test, indirect tensile strength (ITS) test, freeze-thaw cycle test, dry shrinkage and temperature shrinkage test tests with different steel slag contents were carried out. And the strength formation mechanism of steel slag in base material was revealed by SEM. The results show that the strength of the mixture initially increased and then decreased with increasing steel slag content. The frost resistance increased with increasing steel slag content, which should be limited to no more than 75%. Increasing the steel slag content improved the drying shrinkage resistance but was not conducive to the temperature shrinkage resistance. Microscopic analysis shows that adding a suitable amount of steel slag generated a gel material that was distributed inside the pores. This increased the density of the hardened slurry structure, which improved the strength. The research can provide scientific basis for the application and promotion of steel slag in road base.

The Effects of Adding Heartwood Extractives from Acacia confusa on the Lightfastness Improvement of Refined Oriental Lacquer

In this study, a renewable polymeric material, refined oriental lacquer (ROL), used as a wood protective coating, and the Acacia confusa Merr. heartwood extractive, which was added as a natural photostabilizer for improving the lightfastness of ROL, were investigated. The best extract conditions for preparing heartwood extractives and the most suitable amount of addition (0, 1, 3, 5, and 10 phr) were investigated. The lightfastness index including brightness difference (ΔL *), yellowness difference (ΔYI), and color difference (ΔE *), and their applied properties of coating and film were measured. In the manufacture of heartwood extractives, the yield of extractives with acetone solvent was 9.2%, which was higher than that from toluene/ethanol solvent of 2.6%, and also had the most abundant total phenolic contents (535.2 mgGAE/g) and total flavonoid contents (252.3 μgRE/g). According to the SEM inspection and FTIR analysis, the plant gums migration to the surface of films and cracks occurred after UV exposure. The phenomena for photodegradation of ROL films were reduced after the addition of heartwood extractives. Among the different amounts of the heartwood extractives, the 10 phr addition was the best choice; however, the 1 phr heartwood extractive addition already showed noticeable lightfastness improvement. The drying times of ROL were extended and film performances worse with higher additions of heartwood extractives. Among the ROL films with different heartwood extractive additions, the ROL film with 1 phr addition had superior films properties, regarding adhesion and thermal stability, compared with the films of raw oriental lacquer.

Performance Characteristics of Epoxy Modified Open Graded Friction Course (OGFC) By Post-doping Methods

To improve drainage properties and increase driver’s safety in wet weather, epoxy modified Open Graded Friction Course (OGFC) by post-doping methods was proposed. The predominant focus of this paper evaluated the performances of epoxy modified Open Graded Friction Course (OGFC) such as rutting resistance at high-temperature, crack resistance at low temperature, friction, moisture resistance and coefficient of permeability. For comparison, the same NMAS Open friction course with epoxy asphalt which was supplied courtesy of ChemCo Systems Ltd and SK High-Viscosity Asphalt were cited. In addition, the harsh construction requirements and application limitations caused by the residence time of epoxy asphalt were solved by the post-mixing process which was produced by two steps, First step, component B of epoxy asphalt was produced in the backyard plant, then suitable amount of component A was added and mixed evenly while paving in site, affecting the holding time only in the two links of paving and rolling, and the time was easy to control. The results show that epoxy modified Open graded friction Course reinforced with Basalt fiber produced by post-mixing methods has good friction resistance and permeability while retaining satisfactory performance and mechanical properties.

Controlled Release Study on Bifidocin A from a Polyvinyl Alcohol/Chitosan Blend Particle-Based Biodegradable and Active Packaging Coupled with Mechanistic Assessment and Experimental Modeling

On the basis of PVA-CS, which is incorporated with Bifidocin A, anti-microbial biodegradable films were prepared, characterized by their abilities to control the Bifidocin A’s total release rate into foods as needed for packaging of active foods. This study aimed to explore the anti-microbial effects and release kinetics of active substances in polyvinyl alcoholchitosan (PVA-CS) particle composite films added with Bifidocin A. Pseudomonas fluorescens was used as indicator bacteria to evaluate the anti-microbial activity of the films. Fick’s law, power law and negative exponential growth model were applied to further study the release kinetics of Bifidocin A. The results revealed that the composite films of PVA and CS had better mechanical properties and anti-microbial activity when the content of Bifidocin A was 50% with 1:1 PVA/CS, but it impairs the structure of the film, which can be resolved by including a suitable amount of grycerol. The anti-microbial was released faster at higher temperature and concentration of Bifidocin A, and the diffusion coeffcients increased significantlywith the increase of temperature and concentration. According to the thermodynamic parameters, the release of Bifidocin A was endothermic and spontaneous. High correlation factors (R2 > 0.99) were acquired by fitting the release data of the Bifidocin A with the negative exponential growth model. The potential of Bifidocin A to deliver from the films into the food analog appropriately at low temperatures favored the obtained active films to be applied on food packaging, especially suitable for refrigerated foods.

Development of nano-activated carbon and apply it for dyes removal from water

The present study investigates the production of nano-activated carbon from banana peels mixed with nylon 6.6 and polyethene. The carbonization process was carried out by mixing accurate percentages of the banana peels with different ratios of nylon 66 and a suitable amount of potassium hydroxide. The fusion carbonization, without solvents, was used in this paper to decompose the nylon mixture, releasing amino and carboxylate roots that can easily react with the carbon chains. The prepared nano-activated carbon was characterized using different technologies, including SEM, AFM, FT-IR, and EDX technologies. The results showed the produced carbon has spherical particles with a pore size of 1.21 nm and a surface area of 1,071.7 m2/gm. Additionally, it was noticed, from the FT-IR spectrum, the prepared carbon does not contain any active groups, which means it is an inert material. X-ray analysis showed the new carbon is made from carbon (78.57%) and oxygen (21.43%). After optimizing the wavelength, the prepared carbon was used to adsorb methylene blue and Eirochrom black T dyes from solutions. The results showed the best equilibrium time, dose of carbon and concentration of dyes was 40–50 minutes, 0.04 g and 20 ppm, respectively.

Reed Biochar Addition to Composite Filler Enhances Nitrogen Removal from BDBR Systems in Eutrophic Rivers Channel

With the rapid development of urbanization in China, the eutrophication or black stink of urban rivers has become a critical environmental problem. As a research hotspot in wastewater purification, biofilm technology has shortcomings, such as insufficient carbon sources for denitrification. This study used a Biofilm Denitrification Batch Reactor (BDBR) system constructed using reed biochar as the carbon source required in denitrification, significantly accelerating the biofilm formation. To determine the suitable amount of biochar for water purification from the urban eutrophic rivers by the BDBR system, 0%, 5%, 10%, and 15% reed biochar was added to the viscose fiber combined packing. The combined packing reactor involved in this study had a high removal efficiency of the eutrophication channel COD throughout the experiment. However, adding 5% and 10% biochar in the combined filler effectively increased the number of nitrifying and denitrifying bacteria on the biofilm, improved the dominant bacteria diversity and microbial activity, and enhanced denitrification efficiency in the BDBR system. It provides new ideas and methods for developing and applying in situ denitrification technology for urban polluted rivers.

Synthesis and Characterization of Epoxy Resins-Modified Waterborne Polyurethane Emulsion

Aqueous polyurethane emulsion was prepared with diphenylmethane diisocyanate (MDI), polybutylene adipate diol (PBA-1000) as main raw materials and 2, 2-dihydroxymethyl propionic acid (DMPA) as hydrophilic chain extender. On this basis, epoxy resin E-44 was introduced to modify the polyurethane prepolymer, and epoxy resin modified waterborne polyurethane emulsion was obtained. In order to obtain better performance waterborne polyurethane, the effect of DMPA content、the amount of epoxy resin added and modification method on the properties of polyurethane was discussed. The results show that when the DMPA content is 4wt%, the overall performance of the emulsion and the film is the best. And the addition of epoxy resin significantly improves the water resistance, solvent resistance and tensile strength of the waterborne polyurethane film, and its hardness and thermal stability are also improved to a certain extent. When the amount of epoxy resin added is 8wt%, the storage stability decreases significantly, the suitable amount of epoxy resin added is 6wt%. The overall performance of the film obtained by chemical modification is better than that of physical modification.

Use of Palm Oil Clinker in Concrete Research: A Review

Palm oil clinker (POC) is a stone like by-product which is formed in the palm oil mill incinerator after extracted palm oil fibres and shells are burt to generate electricity for mill operation. The electricity is continuously generated. Then, the burnt fibres and shells are thrown at dumping areas as waste. This practice consumes a larger area at the landfills, causing environmental pollution. A review on the physical and chemical properties of POC was presented. The effect of using POC as lightweight aggregates and partial cement replacement on the mechanical properties of concrete produced was reviewed. The integration of suitable amount of POC as cement replacement and lightweight aggregates provided good workability and enhanced the concrete strength. Conclusively, this article has presented information regarding the development in POC concrete research, including the research gaps that remain to be filled.

New Perspective on Thermally Stimulated Luminescence and Crystallization of Barium Borate Oxyfluoride Glasses

The demand for modern materials, especially glasses, used in different applications, such as radiation sensors and spectral converters, requires a detailed study of their properties. The incorporation of fluoride compounds in borate glasses and their crystallization at the nanometric scale allows the properties of these materials to be further enhanced. Although many works showed improvements in some of these properties, some critical aspects, such as the crystallization mechanism and the role of the fluorine phase, need more investigation. We worked with xNaF (100 − x)BaO·2B2O3 glasses with x = 0, 5, 10, 15, 20, 25, 30, and 35% (in mol) to increase the knowledge in this field. The structural modifications and the thermally stimulated luminescence of the glasses were studied, and their crystallization was analyzed by thermal analysis and X-ray diffraction. A continuous trap distribution was found, which was responsible for its very good luminescent signal, especially in glasses with 20% NaF. By selecting a suitable amount of NaF, it is possible to obtain nanocrystals of BaF2. These promising results we reached show the applicability of these materials.

Aptamer Laden Liquid Crystals Biosensing Platform for the Detection of HIV-1 Glycoprotein-120

We report a label-free and simple approach for the detection of glycoprotein-120 (gp-120) using an aptamer-based liquid crystals (LCs) biosensing platform. The LCs are supported on the surface of a modified glass slide with a suitable amount of B40t77 aptamer, allowing the LCs to be homeotropically aligned. A pronounced topological change was observed on the surface due to a specific interaction between B40t77 and gp-120, which led to the disruption of the homeotropic alignment of LCs. This results in a dark-to-bright transition observed under a polarized optical microscope. With the developed biosensing platform, it was possible to not only identify gp-120, but obtained results were analyzed quantitatively through image analysis. The detection limit of the proposed biosensing platform was investigated to be 0.2 µg/mL of gp-120. Regarding selectivity of the developed platform, no response could be detected when gp-120 was replaced by other proteins, such as bovine serum albumin (BSA), hepatitis A virus capsid protein 1 (Hep A VP1) and immunoglobulin G protein (IgG). Due to attributes such as label-free, high specificity and no need for instrumental read-out, the presented biosensing platform provides the potential to develop a working device for the quick detection of HIV-1 gp-120.