CARDIAC FUNCTION OF BASKETBALL PLAYERS UNDER STRESS TRAINING

ABSTRACT Introduction: Basketball can enhance the physical fitness of young people, promote the growth and development of their bodies, and improve health and athletic ability. Objective: To explore the characteristics of basketball players’ cardiac response to increasing load training. Methods: By analyzing 12 juvenile male amateur basketball training athletes, when performing incremental load exercises on the treadmill, using a 12-lead electrocardiograph to record the electrocardiogram, HR, and blood pressure responses for each level of exercise. Results: The mean heart rate of the basketball players before movement was 82.45± 11.44 bpm, slightly higher than the heart rate at rest. Depending on the exercise load, the blood pressure should increase by 5 to 12 mmHg. Under different load training conditions, each level of blood pressure in the Bruce treadmill test procedure should increase 12.5 ~ 44mmHg. The basketball player’s systolic pressure increased by 2.25 ~ 15.7mmHg, diastolic pressure increased by 0.43 to 11.37 mmHg. Conclusions: In basketball players, the psychological stress is less than that of the average person performing the same exercise. The strong ability to adapt to exercise under incremental load training, the contractility of the ventricular muscles and the development of the heart are good. Level of evidence II; Therapeutic studies - investigation of treatment results.

Investigation of the adherence between clay blocks and grouts

This study aims to evaluate the adherence between clay blocks and grouts. For this purpose, push-out and pull-out tests were performed to assess the adherence presented by different combinations of five types of clay blocks and two types of grouts. The results demonstrated that the geometry of the cells of the clay blocks has a preponderant role in their adherence with grout, as the extent of the contact area between grout and block depends on the geometry of the cell. The shrinkage of the grout can cause the formation of cracks at the interface between block and grout, reducing the adherence between the materials. The shrinkage formed inside each type of block can be estimated based on the testing procedure developed in this research and used in conjunction with the geometric characteristics of the cells of the blocks to estimate the maximum load in the push-out tests. The test procedure developed to estimate the percentage of contact area lost due to grouts shrinkage shows to be promising, since its results were used in the equation to estimate the bond strength between blocks and grouts and shown good correlation. However, more study must be done because there are other variables that can affect the results. These results show that it is possible to use different characteristics of blocks and grouts to increase the adherence between these materials and provide a better behavior for reinforced masonry structures. However, it looks like if block types with a grooved hollow cell are used, a bigger contact surface is produced, and a higher bond strength appears to be assured.

Methods for estimating the durability of the needle bearing of the piston head of the connecting rod of a transportation diesel

The article presents the results of an experimental study and analytical evaluation calculations to check service life and increase durability of the needle bearing of piston head of connecting rod of a transport diesel engine. The primary reasons for the violation of the nominal operation of the main units of this mechanism have been established. Corresponding recommendations are proposed for carrying out accelerated tests for durability, reducing the thermal loads of the bearing operation and, as a consequence, improving the quality and service life of its entire piston group. Theoretical and experimental methods for determining the nominal life of the needle bearing of the piston head of the connecting rod (PHCR) of a transport diesel engine are proposed. The theoretical methodology allows obtaining reliable values of durability, taking into account the distribution of the working load over the rolling elements, as well as the mobility of the piston pin and sleeve. The performed calculations make it possible to correct and clarify the standard mathematical model for determining the nominal life of the PHCR needle bearing, depending on the distribution of loads on the rolling elements (rollers) under different operating conditions. This experimental technique with an acceleration factor of 10 is based on a twofold increase in the force effect on the elements of the PHCR needle bearing. This was achieved by assembling the bearing using a special technology, which is described in detail in the work. A significant decrease in the thermal effect and a decrease in radial loads on working rollers have been established. For ensure the regular oil supply into bearing during engine operation, a technique was developed to increase the load on the roller in contact zone, which significantly influenced durability and made it possible to conduct accelerated tests with a reliable yield. Its results of operational research and experience in design work correlate and are sufficiently explained by the developed methods, which allows them to be used for the improvement and modernization of connecting rods with needle bearings in PHCR. That is a permission to use these methodic for doing perfect and modern the needle bearing of the connecting-rod piston. Keywords: diesel, test procedure, needle bearing, rollers, piston head of the connecting rod, durability.

Validation of a Platform for the Electrostatic Characterization of Textile

Floor covering samples of different thickness, pile height, pile design, materials, construction methods, and applied finishes were selected for electrostatic characterization with a standard plotter platform and a newly designed digital platform. There is an existing standard ISO 6356 in which the voltage generated by a human walking on the carpet is measured with human involvement under controlled conditions. A walking person performs the original test procedure to generate the electrostatic charge and manually calculates results. In contrast, the newly designed system does not require a person to calculate peaks and valleys for the generated electrostatic charges, which offers advantages in terms of accuracy, consistency, and reproducibility, and eliminates human error. The electronic platform is extended with an automated foot for a fully automated test, called “automatic mode”, that has a fixed capacitive and resistive circuit, in replace of human body resistance, and capacitance that varies from person to person and over time. The procedure includes both the old and new platforms, where the new platform is placed in a “human walking” mode to compare the two and validate the new device. Next, all the floor coverings are tested in automatic mode with the automated foot to compare and validate results. We conclude that the new testing device can fully characterize the electrostatic behavior of textile without the involvement of a human, which offers advantages in terms of accuracy, consistency, and reproducibility.

Investigation of the Effect of Agarose Gel Concentration and Culture Period on Bio and Mechanical Properties of Chondrocyte Tissue Engineering

As a gel scaffold for chondrocyte tissue engineering, agarose concentration plays a significant role in the relationship between porosity and nutrition. In this work, the effect of concentration and period cultured on Glycosaminoglycan (GAG) and mechanical properties have been studied. A bovine chondrocytes have been isolated and seeded in different agarose gel scoffed concentrations, about 4% and 6%, for different period cultured, 0 and 7 days. The MTS machine and Spectrophotometric with calibration curve method were used to measure mechanical properties, and GAG concentration of the prepared samples, respectively. The results of mechanical tests and GAG contents shown that there are a wide range of dispersion in the most of the samples, which attribute to different factors. For mechanical properties, these factors could be attributed to anisotropic of the produced chondrocyte with agarose scaffolds, insufficient cells' dispersion within the gel scaffold during seeding and cultured time, and some test procedure condition, such as EBSS hydration. While for GAG results, those factors could be the differences of the cell growth environment between in-vitro and in vivo media.

Mosquito Species Composition And Insecticide Resistance Status of Anopheles Arabiensis In Itang Special Woreda, Gambella, Southwestern Ethiopia

Introduction: Anopheles arabiensis, member species of the Anopheles gambiae complex, is the primary vector of malaria widely distributed in Ethiopia. Anopheles funestus, An. pharoensis and An. nili are secondary vectors occurring with limited distribution in the country. Indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs) are pillars for the interventions against malaria control and elimination efforts in Ethiopia. However, the emergence and widespread of insecticide resistance in the major malaria vector, An. arabiensis, might compromise the efforts of the country. The aim of this study was to investigate composition of mosquito species and insecticide resistance status of An. arabiensis in Itang special woreda (district), Gambella, southwestern Ethiopia.Materials and methods: Adult mosquitoes were sampled from September 2020 to Feburary 2021 using Centers for Disease Control and Prevention (CDC) light trap and Pyrethrum Spray Catch (PSC). Moreover, mosquito larvae were also collected from different breeding sites and reared to adults to assess susceptibility status of populations of An. gambiae s.l. in the study area. Susceptibility tests were conducted on two to three days old non blood fed female An. gambiae s.l using insecticide impregnated papers with deltamethrin (0.05%), alpha-cypermethrin (0.05%), propoxur (0.1%), pirimiphos-methyl (0.25%) and bendiocarb (0.1%) following World Health Organization (WHO) standard susceptibility test procedure. Molecular diagnostics were done for the identification of member species of An. gambiae s.l and detection of knockdown resistance (kdr) allele using species specific polymerase chain reaction (PCR) and allele specific PCR. Results: In total, 468 adult mosquitoes were collected from different houses. Culex mosquitoes were the most dominant (80.4%) followed by Anopheles mosquitoes. Three species of Anopheles mosquitoes (An. coustani, An. pharoensis, and An. gambiae (s.l.)) were identified, of which An. coustani was the dominant (8.1%) species. WHO bioassay tests revealed that the populations of An. gambiae s.l in the study area are resistant against alpha-cypermethrin and deltamethrin whereas, susceptible to bendiocarb, pirimiphos-methyl and propoxur. Out of the total 86 An. gambiae s.l specimens assayed, 79 (92%) successfully amplified and identified as An. arabiensis. West African Kdr (L1014F) mutation was detected with high Kdr allele frequency ranging from 67-88%.Conclusion: The detection of target site mutation, kdr L1014F allele, coupled with the phenotypic resistance against alpha-cypermethrin and deltamethrin call for continuous resistance monitoring.

The carrier wave design for the synthesis of non-Gaussian and non-stationary signals using the amplitude modulation method

The methods of generating stationary random signals, both Gaussian and non-Gaussian, are quite complete, but the researches on the non-stationary signals are insufficient. Especially, the current methods seldom provide mathematical bases about the kurtoses of the produced signals such that the generations of non-stationary non-Gaussian signals with the desired kurtoses are inefficient, which also decrease the flexibility of the real-time control in shaker table tests. In the article, the amplitude modulation method is employed to realize the signal synthesis. The carrier waves of the method are investigated considering the bursts overlapping situations. At first, the explicit equations between the kurtoses of the synthesized signals and the three crucial parameters (the offset, the distance between a pair of adjacent bursts and the parameter of the Beta-distributed random variables) are deduced for the carrier waves with both overlapped bursts and non-overlapped busts. Meanwhile, to solve the power spectral density variation led by the amplitude modulation method, an explicit expression of a rescaling parameter is also proposed. Furthermore, the impacts of the three parameters are investigated; the focus of the investigation is on how the kurtoses of the synthesized signals are changed by the parameters. Based on the results of the investigation, a test procedure is put forward to apply the proposed equations in a shaker table test. The control process of the test demonstrates that the real-time kurtoses control can be achieved efficiently with the help of the newly proposed equations.

Options to improve the coagulation process operation in a drinking water treatment plant. Case study

Aluminum salts are widely used across Romania in surface water treatment as coagulants. It is well-known that the efficiency of these coagulants has a complex dependency on the nature of the raw water, being affected by temperature, pH, and suspended solids. The objective of this case study was to compare the coagulation-flocculation efficiency process of raw water from the Bega River, at low temperature and turbidity, taking into account the use of alternative coagulating agents such as alum, poly aluminum chloride (PAC), and their mixing in 1:1 ratio. The raw water samples were treated using the "Jar Test" procedure, comparable with the current plant conditions at Timisoara Waterworks and taking into account possible operational improvements. For the mixture method applied in which was combined alum and PAC in 1:1 mixing ratio were achieved lower concentrations in aluminum residual, TOC, and turbidity.