Papers by Keyword: Regeneration

Abstract: Regenerating cellulose (cotton) through anti-solvent precipitation is a promising method for recycling textile waste. The selection of an anti-solvent during the regeneration of cellulose depends on its molecular structure. In this study, dissolved cotton in dimethyl sulfoxide (DMSO) was treated with five different anti-solvents for cellulose: sodium hydroxide (NaOH), hydrochloric acid (HCl), calcium chloride (CaCl₂) solution, ethanol, and water. The results show that water is adequate in regenerating cotton by up to 20%. The FTIR study was performed to analyze changes in the chemical structure of regenerated cotton following regeneration with different solvents. The C-H bend peak observed around 800-900 cm-1 confirmed that the main β-glycosidic bonds in cellulose were retained across all samples after the regeneration process. Each anti-solvent altered the cellulose structure by modifying hydrogen bonding through specific rearrangements in the chain packing. This is reflected in the lateral-order index (LOI), which represents the ratio of crystalline to amorphous regions. By comparing the lateral-order index (LOI) A1430/A886 from FTIR peak and UV-vis absorbance, the result confirmed that the ranking of effective regeneration using anti-solvent was H2O > NaOH > CaCl₂, ethanol > HCl.

Abstract: Regeneration of industrial catalysts is a better way of increasing the catalytic activity of a catalyst. These catalysts are used in the production of sulfuric acid, in the conversion of sulfur dioxide to sulfur trioxide. They lose their efficiency and activity over time, so it is preferable to regenerate the catalyst instead of discarding it as waste, using a thermal regeneration method followed by chemical treatment by impregnation with different percentages of V₂O₅, 10%, 20% and 30%. They are then examined using techniques known as XRD and FTIR. The IR spectrum shows that the catalyst doped with 30% V₂O₅ has the same bands as the fresh catalyst. Finally, the catalytic test carried out by iodometric assay shows that the catalyst regenerated with 20% V₂O₅ has a conversion rate of 63%, identical to that of fresh catalyst.

Abstract: Water pollution by heavy metals constitutes a significant environmental and health risk, necessitating efficient and reusable adsorbents. The current study investigates the application of inexpensive biopolymer chitosan to extract Ni²⁺ and Cd²⁺ ions from aqueous solutions. Material characterization using X-ray diffraction (XRD) showed the amorphous nature (absence of peak at 10°), and Brunauer-Emmett-Teller (BET) analysis exhibited the mesoporous surface area of 302.12 m²/g, suitable for the adsorption of metal ions. The Swan model was parameterized with batch-derived adsorption parameters (i.e., Qₘₐₓ = 220 mg/g for Ni²⁺, 226 mg/g for Cd²⁺) and successfully predicted packed-bed breakthrough curves at optimum pH (7 for Ni²⁺, 6 for Cd²⁺), with transport rates of 3.65 × 10^-11 m²/s (Ni²⁺) and 3.14 × 10^-11 m²⁺/s (Cd²⁺) for a 1.2 m column. The material retained over 95% removal efficiency after five regeneration cycles. These findings show the potential of chitosan for large-scale water treatment with high efficiency, model-driven design, and strong reusability.

Abstract: A proposal has been presented for the regeneration of a spent sorbent mixture, comprising activated carbon (BAU-A brand) and kieselguhr (Bekogur 200 brand), in a mass ratio of 1:3. The effectiveness of the regeneration process and the potential applications of the spent sorbents were determined through X-ray phase analysis methods. The study included an investigation into the adsorption of the primary dye (methylene blue) by activated carbon and various sorbent mixtures. The observed efficiency of regeneration supports the recommendation of using a combination of kieselguhr and activated carbon sorbents for treating wastewater in food industry enterprises.

Abstract: The article analyzes the reasons hindering the mass use of alternative fuels in the field of energy consumption of domestic transport, which for the most part have lower energy and kinetic indicators of combustion in comparison with traditional fuels. A new approach to solving the problem of improving the environmental and energy-saving indicators of combustion of alternative fuels based on their preliminary thermochemical processing - conversion on board a vehicle is presented. The results of a preliminary analytical study of the parameters of the on-board conversion process for a number of potentially acceptable types of alternative fuels are presented in order to assess the efficiency of this process. The possibility of practical implementation of the proposed process for improving the combustion indicators of alternative fuel with an assessment of its efficiency was tested based on the results of experimental approbation in the conditions of full-scale engine tests. According on the results of the study, the expediency of using this process in transport technologies is justified due to the technical simplicity of its implementation and efficiency. Thermocatalytic reactor is the simplest design of a heat exchanger, the mass and dimensional characteristics of which (in the volume of a conventional muffler) ensure the convenience of its installation in the engine exhaust system. The component composition of these products contains reactive compounds that contribute to the improvement of environmental and energy-saving indicators of the fuel combustion process, and an increase in the efficiency of the engine's operating cycle.

Abstract: The sequence and development of the life cycle of a machine-building product are described. Metals recycling, specifically hard alloys, is considered one of the important economically profitable directions of production development. The evaluation of the efficiency of such a method is given in the example of the explosive processing of hard alloys.

Abstract: Bentonite has strong adsorption for cationic dyes. But as dye absorbent, it's difficult for them to recycle and regenerate. In order to solve these problems, a kind of magnetism bentonite composite was prepared by coprecipitation method, and H₂O₂/UV process was attempted to regenerate the spent composite. The results showed that the composite still has high adsorption performance for cationic dye methylene blue (MB), and the introduction of magnetite can achieve rapid solid-liquid seperation of composite in the external magnetic field. For the spent composite, its adsorption performance could be recovered by H₂O₂/UV process. The recovery effect is directly related to the dosage of hydrogen peroxide. In this study, as the dosage of hydrogen peroxide was 3% (volume ratio), the adsorption efficiency of spent composite for MB could almost return to its initial level after 3h regeneration. This research is of great significance to improve the utilization of bentonite adsorbent in water treatment engineering, and can also provide technical reference for the recycle and regeneration of other adsorbent materials.

Abstract: A high risk of complications in burn injuries is associated with the development of systemic inflammatory response syndrome. Thermal injury (burn) causes the release of cytokines and prostaglandia, resulting in increased interaction between leukocytes, platelets and endothelial cells. Activation of leukocytes leads to an increase in the formation of reactive oxygen species (ROS) and nitrogen, which is normally compensated by the activation of protective antioxidant enzymes. An imbalance between the activity of the radical-producing and antioxidant systems leads to an excess of free radicals and the development of oxidative stress. Oxidative stress limits the repair of damaged tissue and also leads to localized chronic inflammation. Thus, the removal of inflammation and a decrease in the ROS level, which exceeds the physiological level in the burn zone, seems to be expedient for accelerating the healing process of burn injuries of the skin. In this study, we used a polysaccharide hydrogel modified with cerium dioxide (CeO₂) nanoparticles, which have unique anti-inflammatory and antioxidant properties, as an effective agent for the treatment of thermal burns. It has been shown that modification of the hydrogel with CeO₂ nanoparticles provides accelerated healing of a model burn wound in rats. Already on the 5th day after the treatment of damage to the skin with the modified hydrogel, a decrease in the area of ​​the burn wound that is different from the control is observed. The use of a hydrogel accelerates the healing process of a burn wound on the 25th day by 25.42% (p <0.05) and ensures complete healing of burn wounds on average 5 days earlier in comparison with the control group with Levomekol ointment. Treatment of burn wounds using a hydrogel leads to the formation of a small post-burn scar. Thus, a polysaccharide hydrogel modified with CeO₂ nanoparticles can be considered as an effective wound healing agent in the treatment of thermal burns and skin lesions of various etiologies.

Abstract: The tissue engineering approach for periodontal tissue regeneration using a combination of stem cells and scaffold has been vastly developed. Mesenchymal Stem Cells (MSCs) seeded with Bovine Teeth Scaffold (BTSc) can repair alveolar bone damage in periodontitis cases. The alveolar bone regeneration process was analyzed by micro-computed tomography (µ-CT) to observe the structure of bone growth and to visualize the scaffold in 3-Dimensional (3D). The purpose of this study is to analyze alveolar bone regeneration by µ-CT following the combination of MSCs and bovine teeth scaffold (MSCs-BTSc) implantation in the Wistar rat periodontitis model. Methods. MSCs were cultured from adipose-derived mesenchymal stem cells of rats. BTSc was taken from bovine teeth and freeze-dried with a particle size of 150-355 µm. MSCs were seeded on BTSc for 24 hours and transplanted in a rat model of periodontitis. Thirty-five Wistar rats were made as periodontitis models with LPS induction from P. gingivalis injected to the buccal section of interproximal gingiva between the first and the second mandibular right-molar teeth for six weeks. There were seven groups (control group, BTSc group on day 7, BTSc group on day 14, BTSc group on day 28, MSCs-BTSc group on day 7, MSCs-BTSc group on day 14, MSCs-BTSc group on day 28). The mandibular alveolar bone was analyzed and visualized in 3D with µ-CT to observe any new bone growth. Statistical Analysis. Group data were subjected to the Kruskal Wallis test followed by the Mann-Whitney (p <0.05). The µ-CT qualitative analysis shows a fibrous structure, which indicates the existence of new bone regeneration. Quantitative analysis of the periodontitis model showed a significant difference between the control model and the model with the alveolar bone resorption (p <0.05). The bone volume and density measurements revealed that the MSCs-BTSc group on day 28 formed new bone compared to other groups (p <0.05). Administration of MSCs-BTSc combination has the potential to form new alveolar bone.

Abstract: Sorangium cellulosum can product many secondary metabolites that is unique structural and makes these microorganisms highly attractive for drug development, especially epothilone, on cancer cells a cytotoxic macrolide which is naturally produced by Soxhlet cellulose that have the action of microtubule stabilization, is a promising anticancer drug. In this research, the factors affecting the regeneration and preparation of the protoplast of Sorangium cellulosum were discussed, those were regeneration media, enzymes and osmotic stabilizers. This study provide the distruction for improving the production of epothilone through genome shuffling, mutation, fusion and transformation.