Electronic Load Controller based on Dimmer Circuit and Stepper Motor for 5 kW Micro-Hydro Power Plant

This paper presents the results of research on a new schematic generator load controller simulation, namely an electronic load controller based on a dimmer circuit and a stepper motor for a small-scale 5 kW micro-hydro. The load controller is built from a dimmer circuit and a stepper motor with program control using Matlab software, and the PPI 8255 interface device. Using a dimmer circuit built from diac, triac, a variable resistor (pot), and capacitor components. As well as using a 28BYJ-48 stepper motor. Simulation is made to determine the performance of the load controller in controlling the distribution of power to the ballast load when the generator supplies power to consumers less than the full load of the generator. By using the simulation data of 45 variations of the consumer load sample, the result is that there are only 4 samples where the load controller is not working well. For the 4 samples, the generator was loaded beyond its full load tolerance limit (full load tolerance of 5kW ± 5 %). Overall, based on the simulation results, it can be said that the generator load controllers tested in this study have good performance. HIGHLIGHTS Methods and power electronic configurations used in electronic load controllers for micro-hydropower plants from 1980 until now. In the future, the use of low-power micro hydro and pico hydro power plants is also in great demand, especially for rural areas The utilization of micro-hydro in Indonesia, especially low-power micro-hydro, has been utilized by the community in Bulukumba Regency, South Sulawesi Province. A 5 kW generator has been operated in Katimbang Village, Borong Rappoa District, Kindang Regency, Bulukumba Regency, South Sulawesi Province to distribute electrical energy to 15 households This research proposes a new electronic load control scheme for a simple and inexpensive 5 kW micro-hydro power plant, namely a dimmer circuit and stepper motor-based generator load controller. With the consideration that the main components that make up this controller are not expensive GRAPHICAL ABSTRACT

Regulating Movement Frequency and Speed: Implications for Lumbar Spine Load Management Strategies Demonstrated Using an In Vitro Porcine Model

The relationship between internal loading dose and low-back injury risk during lifting is well known. However, the implications of movement parameters that influence joint loading rates—movement frequency and speed—on time-dependent spine loading responses remain less documented. This study quantified the effect of loading rate and frequency on the tolerated cumulative loading dose and its relation to joint lifespan. Thirty-two porcine spinal units were exposed to biofidelic compression loading paradigms that differed by joint compression rate (4.2 and 8.3 kN/s) and frequency (30 and 60 cycles per minute). Cyclic compression testing was applied until failure was detected or 10,800 continuous cycles were tolerated. Instantaneous weighting factors were calculated to evaluate the cumulative load and Kaplan–Meier survival probability functions were examined following nonlinear dose normalization of the cyclic lifespan. Significant reductions in cumulative compression were tolerated when spinal units were compressed at 8.3 kN/s (P < .001, 67%) and when loaded at 30 cycles per minute (P = .008, 45%). There was a positive moderate relationship between cumulative load tolerance and normalized cyclic lifespan (R2 = .52), which was supported by joint survivorship functions. The frequency and speed of movement execution should be evaluated in parallel to loading dose for the management of low-back training exposures.

OVERTRAINING SYNDROME IN ATHLETES

Aim: The aim of our study is to reveal the effect of training overload on athletes. Overtraining syndrome (overtraining) is a very difficult, systemic and complex condition to diagnose. This syndrome occurs with decrease in performance, fatigue, deterioration in sleep patterns, and changes in social behavior when the training load increases unconsciously. Many factors affect the rate and recovery time of overtraining syndrome. These factors are the result of continuous loading, load differential, load tolerance and recovery. The coach needs to plan both the training and the recovery process well. Because optimal performance depends on maintaining the delicate balance between training and recovery. Method: Our study is a compilation obtained to provide information from studies on overtraining syndrome. Findings: In the literature, the symptoms of overtraining are examined under 3 headings as sympathetic, parasympathetic and other symptoms. Conclusion: In order to prevent overtraining syndrome, it is necessary to avoid possible effects that harm team performance. Trainers can facilitate this by changing the training period with the recovery period. In addition, they can help their athletes get rid of this syndrome by using techniques such as mild aerobic activities, massage, hot and cold baths, diet, adequate sleep and psychological relaxation. Recommendation: Nutrition, sleep and rest patterns, recovery efforts (regeneration), emotional support, oxygen administration, medication, etc. are the factors that can treat overtraining syndrome.

The effect of various phases of the menstrual cycle on the tolerance of a statoergonometric test

Relevance.Nowadays, there is a worldwide practice of training women for piloting combat aircraft. An important problem arises of studying the tolerability of aerobatic overload by the female body, including during various periods of the ovarian-menstrual cycle. The main aim of the studyis to assess the tolerance of prolonged static tension of the muscles of the lower extremities and the abdominal press, as an equivalent to the tolerance of overload, by women in various phases of ovarian-menstrual cycle. Methods.The static tension of the muscles of the legs and abdominal muscles is modeled using a five-step statergometric test. Tolerance is evaluated by the dynamics of indicators of computer stabilization before and after the test. The study involves 15 healthy women aged 21-23 years. Registration of estimated indicators is carried out in different phases of the ovarian-menstrual cycle. Results.It is established that the postmenstrual phase of ovarian-menstrual cycle is characterized by good tolerance to long-term static tension of the muscles of the legs and abdominal muscles. Load tolerance decreases in the premenstrual phase. Conclusion.The obtained data suggest that the tolerance of aerobatic overload in women may decrease in the premenstrual phase compared with the postmenstrual phase.

Morphology and composition play distinct and complementary roles in the tolerance of plantar skin to mechanical load

Plantar skin on the soles of the feet has a distinct morphology and composition that is thought to enhance its tolerance to mechanical loads, although the individual contributions of morphology and composition have never been quantified. Here, we combine multiscale mechanical testing and computational models of load bearing to quantify the mechanical environment of both plantar and nonplantar skin under load. We find that morphology and composition play distinct and complementary roles in plantar skin’s load tolerance. More specifically, the thick stratum corneum provides protection from stress-based injuries such as skin tears and blisters, while epidermal and dermal compositions provide protection from deformation-based injuries such as pressure ulcers. This work provides insights into the roles of skin morphology and composition more generally and will inform the design of engineered skin substitutes as well as the etiology of skin injury.