36 research outputs found
Water Quality Parameters and Monitoring Soft Surface Water Quality Using Statistical Approaches
Water is the matrix of life and is indispensable on Earth. Water has a multitude of applications and all known life forms depend on it. Therefore, water quality is important for all of us. Water quality can be represented by a set of physical, chemical, biological and bacteriological characteristics. These parameters allow water to be classified in multiple categories leading to its use for a specific purpose. This chapter establishes the connections between external causes and their effect on water quality parameters. In order to provide information on water quality, different Water Quality Index (WQI) models can be used. In order to study the association between water quality parameters, several correlation coefficients have been developed. For a coherent statistical approach, we have used Pearson and Spearman correlations. In order to exemplify the manner in which WQI can be calculated and interpreted, we used a series of data from our previous work, consisting of 13 parameters measured for water samples taken from the Danube River, from Galati City area, Romania
A Logarithmic Mean Divisia Index Decomposition of CO Emissions from Energy Use in Romania
Carbon emissions have become a specific alarming indicators and intricate
challenges that lead an extended argue about climate change. The growing trend
in the utilization of fossil fuels for the economic progress and simultaneously
reducing the carbon quantity has turn into a substantial and global challenge.
The aim of this paper is to examine the driving factors of CO emissions
from energy sector in Romania during the period 2008-2022 emissions using the
log mean Divisia index (LMDI) method and takes into account five items: CO
emissions, primary energy resources, energy consumption, gross domestic product
and population, the driving forces of CO emissions, based on which it was
calculated the contribution of carbon intensity, energy mixes, generating
efficiency, economy, and population. The results indicate that generating
efficiency effect -90968.57 is the largest inhibiting index while economic
effect is the largest positive index 69084.04 having the role of increasing
CO emissions
Productivity differences between southern and northern slopes of Southern Carpathians (Romania) for Norway spruce, silver fir, birch and black alder
Forest vegetation across Southern Carpathians is distributed in altitudinal layers. The aim of this study was to highlight the productivity differences between the Southern and Northern slopes of the Southern Carpathians for Norway spruce, silver fir, birch and black alder. Data from 45 forest management plans (46.329 stands from the Southern slopes and 32.787 stands from the Northern slopes) were used. For each stand, the mean diameter, mean height, age, standing volume, current volume increment and production class were assessed. Elementary statistical methods were used to identify the factors influencing productivity. Significant differences between the Southern and Northern slopes were recorded for silver fir. The volume and the current volume increment were higher on the Northern slopes. In the case of birch and black alder, the same two parameters recorded higher values on the Southern slopes. As regards Norway spruce, insignificant differences were recorded between the two slopes. The correlation between structure type and stand volume was positive and statistically significant in the case of Norway spruce, silver fir and birch, but it was negative in the case of alder. Analysing the correlation between stand volume and the main stand characteristics also revealed a statistically significant positive correlation between age and stand volume for all analysed species. The results of this study are especially interested for the forest managers and forest owners whose aim is to obtain a higher productivity for the studied species
The influence of the specificity of sports specializations on the values of muscle power for female university students
Background: Explosive strength or muscle power plays a decisive role in the motor performance of all athletes. Purpose: Analysis of muscle strength variations for female students of the Faculty of Physical Education and Sport/undergraduate level, according to sports specializations. Mate-rial and method: The study included 77 women (age = 20.48 ± 1.37 years, weight = 58.79 ± 8.92 kg, height = 166.24 ± 7.13 cm), divided into 3 evaluation subgroups (Non-athletes/NA = 40 cases, Team sports games/TSG = 17 cases and IS/Individual sports = 20 cases). Explosive strength rating was based on 7 lower body tests and 6 upper body tests. Manova parametric techniques were applied. Results: The analysis of variance indicates significant differences between the 3 defined groups, the F values correspond to thresholds p 0.05). Top performance values are dominated by sprinters and volleyball players for the low-er body, respectively by handball, volleyball and karate players for the upper body, as-pects confirmed by the studied sources. Conclusion: We did not identify significant differences be-tween the groups of athletes (TSG and IS), and the top values according to sports specialization reinforce the results of other similar studies, the specific effort obviously infusing the perfor-mance in the muscle strength tests
Effectiveness of ballistic exercises for increasing upper body explosive power in physical education lessons for university students
Background and Study Aim. Explosive power is an important element of fitness levels, with fast muscle contractions being required in most physical activities. Study implements and verifies the effects of ballistic exercises with medicine balls of various weights on upper body explosive strength for non-sporting university students.
Material and Methods. The study involved 184 male and 143 female undergraduate students, all 21 years old. These students had no medical contraindications to participating in the activities required by the physical education program. The development of upper body explosive strength was conducted using ballistic exercises, specifically various types of medicine ball throws, over one academic year. The evaluation comprised six tests: Overhand Ball Throw, Overhead Medicine Ball Throw-forward, Overhead Medicine Ball Throw-backward, Medicine Ball Chest Throw, Shot Put - Track and Field, and 30 s Plyometric Push-Ups. These tests were scheduled at three different times during the academic year: October, December, and May.
Results. The results of the Analysis of Variance (ANOVA) with repeated measurements indicate F values associated with statistically significant thresholds (p < 0.05). In contrast, partial eta squared (η²p) values demonstrate a stronger effect of ballistic exercise application for the male group. Significant improvements in results were observed for both genders from one test to another. The differences were notably larger between the test conducted before the winter holiday (December) and the test at the end of the second semester (May) compared to those between the test at the beginning of the academic year (October) and the one before the winter holiday (December). This pattern indicates a clear improvement in muscle strength in the second semester (January-May). The only test where high percentages of men, and especially women, encountered problems was the 30-second Plyometric Push-Ups. In the final tests, 10% of males and 40% of females scored zero.
Conclusions. Ballistic exercises based on various medicine ball throws prove to be an attractive and effective solution to improve upper body muscle strength for non-sporting university students. The application of these exercises can significantly enhance physical education programs by providing clear benefits in terms of strength development. This is particularly evident in environments aimed at general student populations rather than athletes. Furthermore, while the exercises are broadly beneficial, they may require modifications to address the challenges some students face