THE INFLUENCE OF CLIMATIC FACTORS ON THE CHANGE IN THE ELASTIC-STRENGTH INDICATORS OF EPOXY POLYMERS BINDERS USED IN LIQUID THERMAL INSULATION COATINGS
Introduction: Thermal insulating coatings are increasingly being introduced into construction practice for internal and external finishing enclosing structures and pipelines. Thermal insulation coatings are usually made based on polymer binder and mineral fillers. The durability and stability of the properties of heat-insulating materials depend on the type of binder. As a rule, polymers are used as a binder: epoxy resin; silicone rubber; urea-formaldehyde resins; aqueous dispersed polymers - styrene-butadiene, polyvinyl acetate, and acrylate (acrylic and styrene-acrylic). The quality indicator of binders can be assessed by the influence of the seasonality of climatic impact, and as a result, the best elastic strength characteristics of binders can be established after one month to a year of field tests. Aim: To determine the influence of climatic factors on the change in the elastic-strength indicators of epoxy polymers binders used in liquid thermal insulation coatings. Methods: A tensile testing machine of the AGS-X series with the TRAPEZIUM X software was used for mechanical tests. The tests were carried out in accordance with GOST 11262-2017 (ISO 527-2: 2012) "Plastics. Tensile test method". Results and Discussion: The paper discusses the results of experimental studies of the compositions of polymer binders and their resistance to various climatic factors, which will later be used as a polymer binder for thermal insulation coatings based on fine mineral granular systems. Conclusions: When analyzing the changes in the characteristics of polymer samples after exposure to climatic factors, it was found that compositions based on Etal-247 epoxy resin, cured with amine hardeners Etal-1440N, Etal-1460, Etal-1472, and Etal-45M, demonstrate the best elastic strength characteristics after one year of full-scale tests. The high stability of the indicators under consideration allows us to conclude that the use of Etal-247 resin as a base leads to creating of the most climate-resistant epoxy coatings.
Read ArticleADSORPTION STUDIES OF ZINC, COPPER, AND LEAD IONS FROM PHARMACEUTICAL WASTEWATER ONTO SILVER-MODIFIED CLAY ADSORBENT
Background: Industrial wastewater contains pollutants that are detrimental to human health in varied proportions. Among the pollutants are heavy metals, including Zn2+, Pb2+, and Cu2+ found in a characterized pharmaceutical wastewater. Several techniques have been proposed for the heavy metal sequester. However, they are with attendant challenges. The adsorption techniques using clay-metal oxide modified adsorbent/composite such as silver-clay adsorbent is considered suitable for an effective sequestering process. Aims: To develop and characterize Ag/clay adsorbent for pharmaceutical wastewater treatment. Methods: The Ag nanoparticles were synthesized using Parkia biglobossa aqueous leaves extract in an optimization study. The raw clay was beneficiated and doped with silver nanoparticles via the wet impregnation method. The silver-clay adsorbent was characterized using FTIR, XRD, SEM, and EDS characterization tools. The developed adsorbent was used for the batch adsorption process of the heavy metal ion removal from the wastewater. Results and Discussion: The phytochemical analysis and FTIR results of the P. biglobosa showed that the leaf contains phenol, tannin, and flavonoids which acts as reducing, capping, and stabilizing agent required for synthesizing the silver nanoparticles. The prepared silver nanoparticles modified clay adsorbent Ag/clay, have evenly distributed stacks of pseudo-hexagonal plates, are rich in silica, possess silver nanoparticles in the frameworks, and contain functional groups suitable for binding heavy metals. The adsorptions of Zn2+, Pb2+, and Cu2+ from pharmaceutical wastewater onto the silver-modified clay were studied as a function of adsorbent dosage and contact time. The percentage removal results obtained showed that the adsorbent had up to 99.96%, 99.5%, and 99.44% removal efficiency for Zn2+, Pb2+, and Cu2+, respectively, which are better compared with previous studies. The adsorption process was feasible, spontaneous, and exothermic, with Langmuir and Pseudo-second-order models as best fits for the process. Conclusions: The adsorption of selected heavy metal ions onto the green synthesized silver-modified clay adsorbent (Ag/clay) was feasible, spontaneous, and exothermic in the order Zn2+>Pb2+>Cu2+ with Langmuir and Pseudo-second-order model best fitted for the process. These show that the synthesized silver oxide nanoparticles supported on local clay can be used as a potentially low-cost adsorbent to remove heavy metal ions from industrial wastewater.
Read ArticleASSESSMENT OF SERUM SCLEROSTIN LEVEL AS A BIOMARKER ASSOCIATED WITH BONE DISORDERS IN Β-THALASSEMIA PATIENTS IN AL- NAJAF CITY, IRAQ
Background: β-thalassemia is a blood disorder in which the body does not make hemoglobin normally. Aim: To assess serum sclerostin in female patients with beta-thalassemia and compare with the healthy controls and to predict its complication associated with the bone pathophysiology, for designed improvement the lifestyle goodliness for these patients. Material and methods: Sixty-nine female beta-thalassemia (βT) patients (54 βT major and 15 βT Intermedia), aged 8-40 years who dependent on transfused blood, and 20 healthy controls were evaluated serum sclerostin, and was examined the relationship with hematological parameters RBC, Hb, PCV, WBC, PLT, BMI, splenic status, iron, and ferritin levels. The information of beta-thalassemia patients was collected and records by the questioner. Results: A significantly increased serum sclerostin level (mean 26.80±0.91) pg/ml was showed in βT patients compared with the healthy controls (10.03±0.68, p smaller than 0.001) pg/ml. Furthermore, a significant decrease (p smaller than 0.05) of the sclerostin level was observed in β-thalassemia major compared to intermedia β-thalassemia patients. Serum sclerostin level revealed a significant increase in progress age; it is highest in the age group (30-40) year as compared with age group (8-18) and (19-29) year respectively. Sclerostin showed no associations with the RBC, Hb, PCV, and significantly positively correlated (p smaller than 0.05) with serum iron, ferritin levels, WBC, and PLT count. Significantly higher sclerostin levels in splenectomized and underweight groups were observed compared to unsplenectomized and normal-weight groups (p smaller than 0.05) of βT patients. Conclusions: Sclerostin plays an important role in beta-thalassemia patients and can serve as a biomarker associated with the bone pathophysiology and indicator to prevent the continuation of such serious diseases caused by iron overload in these patients.
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