Background: Soil serves as the primary repository for microplastics, yet their impact on soil-dwelling organisms remains insufficiently understood. This study aims to investigate the influence of varying concentrations of microplastics in soil on the absorption of Cd and Cu by Eisenia fetida within an artificial soil matrix. Methods: The artificial soil consisted of kaolinite clay (20% dry weight), quartz sand (70% dry weight), and Sphagnum peat (10% dry weight). Microplastics, derived from worn-out tire rubber, were incorporated into the soil to establish four concentration levels: 5, 25, 50, and 100 grams of tire microplastics per 500 grams of dry soil. Each treatment was inoculated with ten mature earthworms, weighing between 3. 0 and 5. 0 grams. After 14 days, samples were collected for ICP analysis. Results: : The highest accumulation of both metals was observed in treatments with 25, 50, and 100 grams of tire microplastics. The results demonstrated significant disparities in copper and cadmium accumulation in the tissue samples following the introduction of tire wear particles, indicating an augmenting effect of tire particles on metal uptake by the samples. Statistically notable reductions (p < 0. 05) in Cd and Cu concentrations were noted in both the control soil and soil containing microplastics, particularly in the 100-gram microplastic treatment for Cd and the 50-gram microplastic treatment for Cu. Conclusion: Exposure to a combination of microplastics, Cd, and Cu has more pronounced adverse effects on E. fetida, and microplastics enhance the bioavailability of heavy metal ions within the soil environment.

For improvement and stabilization of problematic soils in terms of geotechnical properties, it should be required to use proper materials. Therefore, tire chips is as new option can be suggested. On the other side, disposing of waste tire is one of the environmental problems. In present study, improving bearing capacity of kaolinite clay soil with using granule particle of tire waste (with aim of reducing environmental pollutants) based on laboratory tests have been investigated. Waste tire Granule particles in 1, 3 and 5 mm diameters and 2. 5, 5, 7. 5 and 10 percentage were mixed with clay. For evaluating geotechnical properties of stabilized clayey soil, compaction, uniaxial, direct shear and permeability tests were performed. Results of this study showed that, optimum of particle size and waste tire particle content are respectively 1 mm and 2. 5 percentage (by weight). So that, in this values minimum void ratio significantly decreased in improved specimens. Consequently, bearing capacity and compressibility were growth. Also, with adding waste tire granule particle by a size larger than 1 mm and more 2. 5 % content in improved soil, permeability went up.

The possibility of establishing a correlation between surface characteristics of the components and the distribution morphology of solid particles with mechanical properties of a filled coating is investigated. The surface characteristics of the polymer and filler particle, their adhesion strength and the state of dispersed phase distribution are determined by: contact angle measurement, Butt joint measurement between compact discs of particles and the matrix and scanning electron microscopy, respectively. The results showed that with curing of the unsaturated polyester resin on TiO2 particles, their thermodynamic affinity reduces (contact angle increment). On the other hand, the interfacial adhesion energy between the cured resin and TiO2 surfaces is about 6.7 kJ/m2. Also, with interfacial area increment between the filler and matrix via improvement of the state of mixing, the impact strength (I) and wear (W) of the cured coatings were increased and the W~ I-1 scaling correlation was found between them.

Waste tire rubbers are considered one of the environment pollutants. Increased production of these pollutants has led to more serious consideration of ways to reduce the harms caused by their accumulation in the environment. Therefore, the effects of incorporation of waste rubber crushed particles in two sizes of 1-2 and 3-5 mm and the amounts of 0, 5, 10 and 20 Mg ha-1 in a calcareous soil (0-30 cm depth) on some chemical properties of soil was investigated in Isfahan University of Technology research field (Lavark). This experiment was performed using seven treatments along with a non amended control treatment in a randomized complete block design with three replications in 1387. Eight months after incorporation, soil samples were collected for laboratory analyses. Results of ANOVA tables show that soil pH, electrical conductivity, percentage of total nitrogen and DTPA-extractable concentrations of cadmium, lead, copper and iron were not significantly affected by application of rubber particles. Incorporation of rubber particles into the soil significantly increased soil organic carbon and carbon to nitrogen. Increases in the DTPA-extractable Zn in soils treated with 10 and 20 Mg ha rubber particles in fine and coarse sizes were significant in comparison with the control soil.DTPA-extractable Zn content in the soil treated with 10 and 20 Mg ha 3-5 mm waste tire rubbers particles was about two and three times higher than that in the control treatment, respectively. The results of this study showed that in shorttime, incorporation of crushed tire rubbers particles had no significant effect on most chemical properties of the soil but increased the available Zn content. In this regard, further studies to monitor the effects of adding waste rubber crushed particles on organic matter mineralization, plant toxicity and physical properties of soil in long-term are recommended.

Objective(s): The study aimed to uncover the underlying mechanism linking wear particles to osteoclast differentiation, and we explored the effect of titanium particles of different sizes on CD147 expression and autophagy in macrophages. Materials and Methods: Effects of titanium particles on CD147 and RANKL mRNA were detected by QPCR; protein level of CD147 and Beclin-1 were detected by Western blot; soluble RANKL were detected by ELISA. To determine the effect of CD147 and autophagy, KG-1a cells were transfected with siRNA-CD147 or treated with autophagy inhibitor CQ (chloroquine), and then co-cultured with different sizes of titanium particles. Results: Our results showed that 0. 2-1. 2 μ m and 1. 2-10 μ m titanium particles up-regulate CD147 to activate autophagy, which increase the level of soluble RANKL to promote osteoclastogenesis. Suppression of CD147 with siRNA could diminish particle-induced autophagy and soluble RANKL expression. In addition, CQ could dramatically reduce particle-induced soluble RANKL expression. Conclusion: Our findings suggested a possible mechanism underlying wear debris-induced osteolysis and identified CD147 as a potential therapeutic target in aseptic loosening.

Background and objective: It is a fact that demand for wood products has been increasing with the increasing in the population of the world that adversely influences the sustainable utilization of forest resources. In recent years, there has been widespread interest in the manufacturing of products from recycled materials. Among the waste materials, waste tires are a major concern, because the amount of waste tires is increasing more and more due to the increasing demand for tires and because of their short lifetime, it is therefore necessary to develop methods for recycling waste tires. Effectively recycling waste tires such as manufacturing wood-rubberbased composites could be one of the solutions. This research, physical and mechanical properties of particleboard made from waste tire powder and wood particles were investigated. Materials and methods: The variable in this research were the ratio of waste tire powder to wood chips (at five levels; 0: 100, 10: 90, 20: 80, 30: 70, 40: 60). Industrial wood particles from Sanate Choube Shomal Company were used. Urea formaldehyde resin used at 10 percent level of dry weight of raw material as well as ammonium chloride was used as a catalyst at 2 percent level of the dry weight of adhesive. After the mixing process raw material together, mat at temperature of 170° c for 5 minutes under hot press was placed. Physical and mechanical properties of panels measured according to EN Standard. Also the dispersion of waste tire in particleboard was evaluated by scanning electron microscopy (SEM). Physical and mechanical properties of panels analyzed using variance analysis in 5% probability level. Results: The results showed, increasing waste tire percent resulted in decreasing the bending strength, modulus of elasticity and internal bonding of the boards. Although melting of the tire might be expected to increase bonding strength with the wood, this did not happen at the temperatures applied in this study, because the waste tire might melt at temperatures higher than 170° c. Based on images of scanning electron microscopy, it is clear that tire has not melted at the press temperature and has been created no connection with wood. Water absorption and thickness swelling after 2 and 24 hours immersion in water decreased with increasing of the waste tire content, So that the maximum of WA and TS after 2 and 24 hours of immersion in water were found in control specimens and the minimum value of these factors were found in the boards contain of 40 percent of the waste tire. Conclusion: Results showed, there was usability of the waste tire up to 20 percent for general purpose boards and up to 10 percent for interior fitments (including furniture) for use in dry conditions.

Al-Si alloys are commonly used in the manufacture of auto parts, including pistons. Although this alloy offers desirable properties for use in pistons, several microstructural properties, such as the presence of needle-like silicones or dendrites, interfere with the performance of the components produced. In this study, ZrO2 reinforcing particles were used to produce metal-based composites by friction stir process. First, the microstructural characteristics of the stir zone (SZ) of the samples produced were studied using an optical microscope. The results showed that the friction stir process improves the microstructural properties of the base metal, including the size of the silicon particles, and the distribution of these particles in the base metal. Then the particle distribution and bond quality between ZrO2 and aluminum reinforcing particles were investigated using SEM. Then, hardness and wear tests were performed to determine the wear and hardness of the composites. Pin-on-disk wear tests were performed at speeds of 1 m / s and 2 m / s and normal applied loads of 5 N, 10 N and 20 N. The wear test results showed that the wear resistance of the produced composite was improved by about 172% compared to the base alloy.