Evaluation of the Performance and Ductility Index of Concrete Structures Using Advanced Composite Material Strengthening Methods

The performance of concrete structures deteriorates over time. Thus, improving their performance using fiber-reinforced polymers (FRPs), PS strands, and various strengthening methods is important. Reinforced concrete (RC) and prestressed concrete (PSC) structures develop initial cracks in concrete during bending tests, and destruction occurs over a certain period of time after a certain load is generated, and then after the reinforcements and strands yield. However, in the case of FRP structures, after an initial concrete crack occurs, FRPs exhibit a rapid shape deformation of the structure after yielding. Thus, in this study we used FRP and PS strand materials and evaluated the ductility index using the load-displacement results obtained from structural tests conducted using various strengthening methods. The ductility index evaluation method compares and analyzes the change rates in the ductility index of PSC and RC structures based on a method that uses structural deflection and the derivation of the energy area ratio. The ductility evaluation results based on the energy area ratio at the crack, yield, and ultimate points showed that all the RC structures, except for the specimens strengthened with reinforcing materials from company H, were in the ductility and semi-ductility sections. Thus, all the PSC structures, except for the control specimens and PH4NP, were found to be brittle.

Search Engine Optimization Method of Online Course Management Platform

This study proposes a method of keyword selection in search engine optimization to improve the accuracy of search engine and website rankings. To promote the development of scientific and technological innovation, this paper selects the innovation and entrepreneurship curriculum platform as the experimental object. By comparing different search engine optimization strategies, the keyword search volume data is analyzed based on “comprehensive index evaluation method”, which analyzes and calculates the change of keyword search comparison and the number of related keywords. Therefore, this paper will use the comprehensive index evaluation method for keyword selection, and establish a set of practical keyword selection method combined with the actual situation of innovation and enterprise curriculum platform. The results show that this program can improve search accuracy and website ranking.

FEATURES OF THE CLINICAL STATE OF PERIODONTAL TISSUES IN YOUNG PEOPLE

Relevance of the research topic. The authors found that various risk factors play a leading role in changing the clinical state of periodontal tissues. The aim is a comparative assessment of the clinical condition of periodontal tissues based on the correlation of hygienic and periodontal indices depending on age. Material and methods. A comprehensive clinical examination of 765 young people was conducted. The main group consisted of 70 (66.6%) patients with diagnosed chronic gingivitis and 145 (33.35%) patients with mild initial periodontitis due to the presence of conditionally pathogenic and periodontopathogenic types of microorganisms in the microbial biofilm. The control group was formed by 83 patients whose index evaluation revealed the condition of periodontal tissues in the form of clinically healthy gums with intact periodontal and clinically healthy gums with periodontal tissue loss, respectively, in 61.4 and 38.6% of cases of observations. Study results. In 61.4% of persons forming groups with clinically healthy gums, hygienic and periodontal indices are within normal values, in 38.6% of cases of persons there is a tendency to change them from the norm. In 47.7% and 52.3% of cases of individuals with gingivitis and in 48.3% and 51.7% of individuals with initial periodontitis, the OHI-S index correlates with the indicators of PMA, GI and SBI (p < 0.001, p = 0.315). Conclusions. Thus, the revealed changes in the indicators of hygienic and periodontal indices (the Chuprov conjugacy coefficient is 0.64 (p = 0.012), the Kraskel-Wallis criterion (H = 7.89, p < 0.05) makes it possible to clearly determine the clinical condition of periodontal tissues corresponding to modern European criteria.

Evaluation of urban water security based on DPSIR model

Assessment of urban water security is an important scientific basis for the sustainable utilization of urban water resources. This study established an evaluation model for urban water security based on DPSIR model, entropy method and comprehensive index method. The model was applied to Gong Qingcheng City (GQCC) in Jiangxi Province, China. An indicator system is developed based on four aspects including social development, water resources status, water pollution and water resources management, as well as summing up predecessors’ experience. This study analysed per capita domestic water consumption; ratio of ecological water compensation; percentage of water conservancy and public infrastructure investment; and water consumption per ten thousand yuan of industrial output value; where ratio of urban sewage treatment are the main effects on urban water security. The results of single index evaluation show that the change of stress subsystem was most dramatic from 2013 to 2017, while others were relatively stable. This indicates that positive interventions were urgently needed to relieve pressure of the stress subsystem. The results of comprehensive index evaluation show that water security at GQCC was in a critical state. In this paper, the causal relationship between social development and water security was clarified while the main factors and other factors affecting urban water security was identified. Finally, a reference for the formulation of urban development planning based on water resources demand was provided.

Index evaluation of physical development of students

The article presents materials of a comparative study between index estimates of the physical development of students between two ethnic groups. Physical development is one of the most important indicators of the health not only for the young generation, but also for the whole population. The indices of physical development represent the ratios of individual anthropometric characteristics, which allows them to be used for a rough assessment of physical development in the course of mass surveys of the population, as well as for analyzing the influence of various environmental factors on the body. The study involved 336 girls aged 17 to 20 years studying at Kostanay State Pedagogical University. The studies were conducted in accordance with bioethical rules. All studies were conducted in inter-sessional period, in the first half of the day. Depending on nationality, the respondents were divided into two groups: the first group — students of Kazakh nationality, the second group — students of Slavic nationalities. The studied groups identified the main anthropometric (heihth, body weight, chest circumference), physiometric parameters (vital capacity of the lungs, hand strength, blood pressure), anthropometric (Quetelet, Pigne, Manouvrier) and functional indices (Robinson, Skibinsky, life and dynamometric indices). In the studied groups, significant differences were revealed in the main anthropometric indicators, the characteristics of the Manouvrier index, and the index of life. The revealed excess of the average group indicators of the girl students of the second group is due to the genetic predisposition of the morphological and functional characteristics of the organism.