Average Power Values Research Articles

Reducing Peak Power in a Multiple Load System by Delaying the Activation of Electrical Loads Using a Filter Based on a PI Controller

In a power grid with multiple two-state loads, the total power can vary over a significant range. This results in the inability to supply this system from a low-power source. The solution is an algorithm that shapes energy demand depending on its availability. For this purpose, a new load distribution method is proposed based on introducing a buffer between the temperature controller output and the heater and filtering the load using a master Proportional–Integral (PI) controller. The aim of the work was to evaluate the quality of the developed algorithm for limiting power peaks in the power grid. The research was conducted on a model of the Creep Test Laboratory with 389 heaters simulated in MATLAB Simulink R2023b. The algorithm was tested with various settings of the master controller parameters. By experimentally adjusting these parameters, a ten-fold reduction in peak power was achieved. The standard deviation for the L1 phase was reduced from 7.6 kW to 0.6 kW. Similar results were obtained for phases L2 and L3. The tested control system tracked changes in the average power value by changing the number of loads switched on and by frequency-modulating the signal when the change was less than the power of a single load. It was demonstrated that the controlled delayed switching of electrical loads can modify the shape of the total electric power without affecting their operation. The proposed solution features a low computational complexity, which allows its implementation in various systems.

Rates of ground reaction force development are associated with running speed during sprint acceleration

This study aimed to investigate the relationship between overground sprint performance and rates of force development (RFDs) in ground reaction forces (GRF) during the entire acceleration phase. Thirty-one male sprinters performed 60-m sprints during which the GRF from the start to the 50-m mark were measured. The vertical, braking and propulsive RFDs at each step were calculated as the average rate of change in GRF. Average values for each four steps during the acceleration phase were calculated to examine relationships between running speed or average horizontal external power (AHEP) and RFD values. The RFD values ranged from 859.8 ± 191.1 to 1682.0 ± 258.2 N/s/kg for vertical force, −502.6 ± 215.7 to −1033.8 ± 196.2 N/s/kg for braking force, and 97.2 ± 11.7 to 185.4 ± 32.3 N/s/kg for propulsive force. There were associations of running speed with vertical RFD at the 21st–24th step section (r = 0.385) and with propulsive RFD at the 1st–4th step section and from the 13th–16th to 21st–24th step sections (r = 0.386–0.559). Moreover, AHEP was correlated with vertical RFD from the 13th–16th to 21st–24th step sections (r = 0.442–0.523), with braking RFD at the 17th–20th and 21st–24th step sections (r = −0.423 and −0.448), and with propulsive RFD at every step section (r = 0.374–0.856). In conclusion, greater propulsive RFD throughout the acceleration phase, along with higher braking and vertical RFD during the later acceleration section, may indicate better sprint performance.

Temperature profile during endourological laser activation: introducing the thermal safety distance concept.

To examine temporal-spatial distribution of heat generated upon laser activation in a bench model of renal calyx. To establish reference values for a safety distance between the laser fiber and healthy tissue during laser lithotripsy. We developed an in-vitro experimental setup employing a glass pipette and laser activation under various intra-operative parameters, such as power and presence of irrigation. A thermal camera was used to monitor both temporal and spatial temperature changes during uninterrupted 60-second laser activation. We computed the thermal dose according to Sapareto and Dewey's formula at different distances from the laser fiber tip, in order to determine a safety distance. A positive correlation was observed between average power and the highest recorded temperature (Spearman's coefficient 0.94, p < 0.001). Irrigation was found to reduce the highest recorded temperature, with a maximum average reduction of 9.4°C at 40W (p = 0.002). A positive correlation existed between average power and safety distance values (Spearman's coefficient 0.86, p = 0.001). A thermal dose indicative of tissue damage was observed at 20W without irrigation (safety distance 0.93±0.11mm). While at 40W, irrigation led to slight reduction in mean safety distance (4.47±0.85 vs. 5.22±0.09mm, p = 0.08). Laser settings with an average power greater than 10W deliver a thermal dose indicative of tissue damage, which increases with higher average power values. According to safety distance values from this study, a maximum of 10W should be used in the ureter, and a maximum of 20W should be used in kidney in presence of irrigation.

Anaerobic Abilities Students Using Indirect Tests: Fatigue Index and Peak Power

Background: Most human movements are supported by its functional capabilities of the anaerobic type, which is dominated by submaximal and maximal sports activities performed in a short time. Functional capabilities of the anaerobic type of man participate in most of his movement activities. Conditioned on adequate and extremely good interaction and functioning of the cardiovascular and respiratory systems, morphological status, metabolic processes, muscle structure, nutritional status, physical activity, etc. Purpose: The research was conducted in the conditions of the so-called field testing with the primary goal of assessing the acute state of anaerobic abilities of physical and sports students, by calculating the fatigue index (FI). Methods: The sample included 80 students of Physical and Sports Education, different geographical regions, average weight 77.88±8.49kg, age 20-23 years. The Running Anaerobic Sprint Test (RAST) was used to assess FI, and the basic statistical parameters were calculated. Results: The average value of the student's leg power is 573.89 watts (378.42 watts vs. 817.99watts), and the recorded average (FI) of 8.35 watts/sec (3.97watts/sec. vs. 16.93watts/sec.). Conclusions: The obtained results confirmed the average values of anaerobic capacity which are suitable for the examined population of subjects, while the maximal the value of FI suggests a weaker state of the anaerobic capacity of the individuals (less tolerance to lactates).

Performance improvement of the self-power control valve based on digital twin technology

Providing stable energy for intelligent pipe network systems is a complex problem. Ball valves are widely used in intelligent pipe network systems, and a self-power control valve is designed by integrating a flow-matching wheel in the ball valve. While the spool is throttling the fluid, a part of the energy can be extracted from the fluid and converted into the power. In order to optimize the energy capturing characteristics of the self-power control valve, the shape of the flow-matching wheel must be designed to form a precise match with the valve cavity. In this paper, a lightweight digital twin of the self-power control valve is developed using an agent model. Based on this, an optimized design method for the flow-matching wheel that can dynamically take into account the operating conditions of the valve in real time, is proposed by combining the agent model with the dynamic data from multiple sensor sources. The research results show that after the twin optimization of the flow-matching wheel, the average value of the energy capturing efficiency is improved by 3.21 % compared to the pre-optimization; the average value of the output power is improved by 20.57 % compared to the pre-optimization.

The Effect of Varying Artificial Neural Network and Adaptive Neuro-Fuzzy Inference System Parameters on Wind Energy Prediction: A Comparative Study

Owing to the development of technology, the majority of nations throughout the world now rely on fossil fuels and nuclear power plants to meet their energy needs. However, as academic research on this subject has shown, it has become clear that alternative energy uses are necessary due to the gradual depletion of these fuels and their significant negative effects on the environment. In order to ensure energy diversity and end the energy shortage, the development of renewable energy sources is crucial. The prediction of wind power is crucial for effectively utilizing the potential of wind energy. In this study, an adaptive neuro-fuzzy inference system (ANFIS) and an artificial neural network (ANN) have been developed for the prediction of wind power. In this study, data sets were created by taking the daily average wind speeds of the selected wind turbine, the daily average power values it produces, and the daily average wind speed values in the Velimese region. By creating single-hidden layer and multi-hidden layer ANN models, the network was trained multiple times with different activation functions and different numbers of neurons, and wind power prediction was performed. In the ANFIS model, the number of membership functions is kept constant, and wind power prediction is performed using different membership functions. With these ANFIS and ANN models developed with different parameter combinations, it is aimed to determine the most efficient model by performing daily average wind power prediction. Parameter combinations were tested to determine the appropriate models, and as a result, the ANN and ANFIS models were compared with each other.

Performance evaluation and optimal design for passive turbulence control-based hydrokinetic energy harvester using EWM-based TOPSIS

Passive turbulence control (PTC) in the form of square-shaped rods (SSR) is applied to improve the performance of the flow-induced vibration (FIV)-based energy harvester. The influence of SSR installation positions (θ) on the mechanical power and hydroelastic efficiency of SSR-cylinders is studied experimentally. Vortex-induced vibration (VIV) and VIV-galloping coupling modes are observed in this research. It is found that the SSR-cylinder with θ = 150° (VIV-galloping coupling) achieves the highest mechanical power, while the SSR-cylinder with θ = 180° (VIV) attains the highest hydroelastic efficiency. To evaluate the performance of energy harvesting and find the optimal design of the oscillator, the technique for order of preference by similarity to ideal solution (TOPSIS) is employed. The TOPSIS method considers both the average and maximum values of mechanical power and hydroelastic efficiency, with data-driven and adaptive weights estimated using the entropy weight method (EWM). It is indicated that the SSR installed at 150° obtains the optimal performance in a wide flow velocity range, followed by 140° and 70°. Finally, the effectiveness of the optimal design is validated by comparing it with other harvesters and the rationality of the proposed EWM-based TOPSIS method is analyzed in detail.

Effectiveness of repellent from patchouli (Pogestemon cablin) varieties of Southeast Sulawesi against Aedes aegypti.

The incidence of Dengue Hemorrhagic Fever (DHF) continues to increase over time in the world, including Indonesia. One of the prevention efforts against dengue virus transmission is to avoid vector mosquito bites by the use of repellants. Using repellents can reduce exposure to mosquito bites that may cause infection with the dengue virus. This study aimed to determine the effectiveness of repellent lotion composed of patchouli batik extract (Pogostemon cablin) from Southeast Sulawesi varieties against Aedes aegypti mosquitoes. The research subjects were Aedes aegypti adult mosquitoes. The research consisted of three stages. The first stage was a phytochemical test (qualitative method), the second stage was the analysis of patchouli essential oil (GC-MS method) and the third stage was a test of the effectiveness of lotions made from patchouli extract in lotion preparations against Aedes aegypti. The results of the effectiveness test of patchouli leaf repellent (Pogestemon cablin) lotion preparations were as follows: for a concentration of 2.5%, protective power 81.5%; concentration 5%, protection power 83.67%; concentration 7.5%, protection power 88.64 %; the concentration of 10%, protection power 90.44%, and the concentration of 12.5% had protection power 90.89%. Probit analysis and linear regression showed the value of ProbitLc 50 was 6.631. The results of the effectiveness test of Pogestemon cablin repellent lotion preparations with the most effective concentrations were 10% and 12.5%. The results of ANOVA test indicated there was no difference in the average value of the protection power in patchouli leaves.

The Analysis of the Effects of Interval Training Program on Aerobic and Anaerobic Performance in Slalom and Giant Slalom Athletes

The purpose of this study is to analyze the effects of interval training on the aerobic and anaerobic performance of elite-level athletes in slalom and giant slalom disciplines. The study consisted of thirteen male athletes in the alpine skiing discipline (slalom-giant slalom). The heights of the athletes were measured with a stadiometer with a precision of ±1mm (Holtain, UK). Weight measurements were conducted using a Tanita brand body composition analyzer (BC, 418 Tanita, Japan) with a precision of 100 grams. For aerobic power and capacity testing, a breath-by-breath measurement method was employed using the Cosmed K5 portable gas analysis system (Italy). The MaxVO2 protocol was performed on a cycle ergometer, and the anaerobic power and capacity test were conducted using the Wingate method. Aerobic/anaerobic power values of athletes were measured twice, before and after a 4-week interval training program. An Independent Samples T-Test was used to identify differences between pre-test and post-test values of athletes. Significant relationships were found between pre-test and post-test values of MaxVO2, peak power, average power, and power drop percentage for slalom and giant slalom athletes subjected to interval training (p0.05). In conclusion, interval training was observed to increase body muscle mass, reduce body fat percentage, and enhance aerobic and anaerobic capacity in slalom and giant slalom athletes. Including interval training in the content of athletes' training programs when creating annual training plans is considered to positively influence aerobic and anaerobic performance using the interval training method.

An analysis of the expected wave conditions in the Mediterranean Sea in the context of global warming

The main objective of the work proposed herewith is to assess the climate change impact on sea state conditions in the Mediterranean Sea under Representative Concentration Pathways and Shared Socio-economic Pathways scenarios and its expected dynamics in the near future. To perform this, the analysis is structured in two-time intervals, each one covering 30 years. The first period represents the recent past, while the second comprises the near future (2041–2070) under the RCP8.5 and SSP5-8.5 scenarios. A wave modelling system based on the SWAN (Simulating WAves Nearshore) model is implemented and validated in the target area using ERA5 wind data to drive the wave model for the recent past. Then, for the same period, simulations with the wave modelling system forced by the Regional Climate Model wind fields are carried out. For the near future, wind fields under the above-mentioned scenarios are considered to drive the wave model. Various analyses and comparisons are performed to identify the climate change impacts on the wave climate and wave power, to evaluate the differences between the results obtained for each scenario, and also the evolution of the characteristics of the extreme values in the Mediterranean Sea basin. No high differences between the average values of significant wave height and wave power obtained under the two scenarios along the entire basin of the Mediterranean Sea were found. In the marginal seas sometimes different trends appear, especially in the Aegean and Tyrrhenian Seas. Regarding the 99th percentile of Hs, under the SSP5-8.5 scenario, they are slightly higher than those under the RCP8.5 scenario.

Combined Methods for Developing the Specific Strength of Women Long Jumpers U18

Background and Study Aim. It is well known that neuromuscular electrostimulation and plyometric exercises positively influence the gain of explosive force in the lower limbs. The combination of plyometric method and electrostimulation begins to gain a positive trend, being included in the modern training of athletes due to the important gain of explosive force. The purpose of this study is to investigate the effects of combining plyometric and electrostimulation methods in specific training for the development of lower limb muscle strength in long jumpers. Material and Methods. The study was conducted on 15 women's long jump athletes, age category 18 years ± 1,622, with an average weight of 50.80 kg ± 3,932, height of 165.87cm ±3,292 and foot plant of 39.00 ±1,254. The group carried out the experimental training program for a duration of 12 weeks, with means specific to the two methods, three times a week, lasting 60 minutes. It was assessed: horizontal speed on the last 10m of the run up, 1 RM (a maximum rep for a squat); vertical jump; flight time and performance achieved in the competition. The maximum repetition for a squat was tested with the GykoRePower system, the vertical jump was determined with the OptoJump Next system, and the performance in the test was recorded during the competition. The vertical jump, the average value of power used to develop the explosive force and the length of the jump were evaluated. The recorded data on the muscle profile of the subjects were analyzed with the SPSS statistical analysis program Results. The statistical analysis performed with T-student obtained significant differences between the two tests of the experiment group (p ≤ 0.001): 1RM registers a progress of 10.476 kg with a progress rate of 18.07%, optimal load registers a progress of 3.627 kg with a progress rate of 8.93%, vertical jump achieves a progress of 4.567 cm with a progress rate of 16.09% with a flight time progress of 0.03833 s with a progress rate of 7.39%, and the speed on the last 10 m of run up progresses by 0.5234 s with a progress rate of 6.79%. Subjects recorded a progress for competition performance of 36.467 cm compared to the initial test with a progress rate of 8.50%. Conclusions. The research results are objective arguments that highlight that a specific training based on combining plyometric method with electrostimulation determines significant improvements in the development of explosive force of the lower limbs in long jumps with positive effects on sports performance for long jumpers.

Comparison between Early Clinical Results of Dual-Linear and Conventional Foot-Pedal Control in Phacoemulsification

Background: The aim of this study was to compare early clinical results regarding the safety and efficacy of dual-linear vs. conventional foot-pedal control in cataract surgery. Methods: This was a paired-eye contralateral, retrospective, observational study. Each patient underwent cataract surgery in both eyes: one eye with dual-linear foot-pedal control (study group) and the other eye with conventional foot-pedal control (control group). Absolute phaco time (APT), average phaco power, effective phaco time (EPT), and surgical complications were analyzed and compared. Corneal endothelial cell count, corneal thickness, corneal volume, and best-corrected distance visual acuity (BCDVA) were measured preoperatively and at 1 week, 1 month, and 3 months postoperatively. Results: A total of 94 patients (188 eyes) were enrolled. The respective APT, average phaco power, and EPT values were 7.05 ± 5.31 s, 28.4 ± 1.00, and 2.05 ± 1.56 s in the study group and 6.82 ± 6.48 s, 18.9 ± 1.74, and 1.35 ± 1.35 s in the control group. Conclusions: The average phaco power and EPT values were significantly higher in the study group. The safety of the dual-linear foot pedal was comparable to that of a conventional pedal in terms of endothelial cell loss, central corneal thickness, and surgical complications.

Feeding a Membrane-less Microbial Fuel Cell by Mixed Municipal and Industrial Wastewater

Due to the constant growth of the world's population, the amount of generated wastewater is also constantly increasing. One of the devices that can use wastewater as a raw material for energy production is a microbial fuel cell (MFC). MFCs technology is constantly evolving. However, to increase its use, it is necessary to improve its efficiency. There are various possibilities to ensure this, such as the use of new electrode materials, new cell designs, or the use of wastewaters from different sources. In this paper the analysis of MFC operation (cell voltage, power, and current density) fed by mixed municipal and industrial wastewaters was shown. Moreover, the change in time of COD was analyzed. Due to cost reduction the membrane-less microbial fuel cell (ML-MFC) was chosen. It was noted that the addition of concentrated process wastewater increases the COD reduction time in the ML-MFC. An increase of generated bioelectricity during fed ML-MFC by mixed municipal and industrial (process wastewater from yeast production) wastewater was demonstrated. The highest values of average cell voltage (598 mV), maximum power (4.47 mW) and maximum current density (0.26 mA·cm-2) were obtained for a 10% share of yeast process wastewater in the mixed wastewater, which fed the ML-MFC.

A power-based fault direction estimation method for active distribution networks

This paper presents a strategy for estimating fault direction in active distribution networks, focusing on the high penetration of distributed energy resources, changing operating conditions, untransposed lines, and unbalanced loads.The proposed strategy introduces a power-based directional criterion derived from analysing active power within three-phase unbalanced systems known for their inherent unidirectional nature. The method enables rapid direction estimation by measuring the difference between pre-fault average active power and during-fault average active power values, utilising two moving windows. Notably, this difference is positive for forward faults and negative for backward faults, offering clear directionality insights. The strategy is validated using a modified IEEE 34-bus test system, where it demonstrates feasibility under several fault scenarios, including all fault types, varying fault impedance, operating conditions, noise levels, and sampling frequencies. Additionally, the proposed algorithm is compared with contemporary and conventional approaches, highlighting its effectiveness.

Low repetition rate passive mode-locked semiconductor disk laser

Semiconductor disk lasers (SDLs) have advantages of high output power and good beam quality. Their flexible external cavity provides convenience for inserting additional optical element to start mode locking and produce ultra-short pulse train with duration from picosecond to femtosecond. However, the very short lifetime in a range from about a few nanoseconds to tens of nanoseconds of the carrier in semiconductor gain medium limits the decrease of pulse repetition rate, thus restricting the increase of peak power of the mode-locked laser pulse to some extent. In this work, by using the relatively shallow In&lt;sub&gt;0.2&lt;/sub&gt;GaAs quantum wells, which have a relatively long carrier lifetime in the active region of gain chip, as well as the particularly designed semiconductor saturable absorption mirror (SESAM) that has a relatively small saturation flux, a passively mode-locked SDL with low repetition rate and high peak power is demonstrated. The used six-mirror cavity has a spot radius of about 200 μm on the chip and a 40 μm spot on the SESAM, and the total cavity length is about 1.92 m. The SESAM passively mode-locked SDL produces a stable pulse train with a lowest repetition rate of 78 MHz. When the temperature is 12 ℃ and the transmittance of the output coupler is &lt;i&gt;T&lt;/i&gt; = 3%, an average output power value of 2.1 W and a pulse duration of 2.08 ps are achieved. The corresponding pulse peak power reaches 12.8 kW, which is about twice the reported highest peak power in an SESAM mode-locked SDL. When &lt;i&gt;T&lt;/i&gt; = 2% and &lt;i&gt;T&lt;/i&gt; = 5%, the obtained average output power values are 1.34 W and 1.62 W respectively, and the corresponding pulse peak power values are 8.17 kW and 9.88 kW. Based on the values reported in the literature and the results of pulse repetition rate in our experiments, the estimated lifetime of the carriers of the In&lt;sub&gt;0.2&lt;/sub&gt;GaAs quantum wells in the active region of the gain used chip is 16.4 ns. This high peak power mode-locked semiconductor disk laser has important potential applications in biomedical photonics, chemistry, and nonlinear microscopy.

Spatially Structured Optical Pump for Laser Generation Tuning.

The goal and essential parameter of laser light conversion is achieving emitted radiation of higher brightness. For many applications, the laser beam must have the highest available beam quality and highest achievable power. However, lasers with higher average power values usually have poorer beam quality, limiting the achievable brightness. Here, we present a method for improving the beam quality by using a spatially structured optical pump for a membrane external cavity laser resonator. An increase in brightness is achieved under fixed focusing conditions just by changing the pump intensity profile. A controllable output laser mode can be achieved by using a dynamically changing pump pattern.

SDR-Based Portable System for Evaluating Exposure to Ambient Electromagnetic Fields

This paper discusses the need to accurately determine the population’s exposure to low-intensity radio-frequency electromagnetic fields (RF-EMF) from modern technologies like mobile networks, Wi-Fi, and IoT and proposes a practical solution for this assessment. There is no scientific consensus on the biological effects, mostly due to challenges in conducting accurate biological experiments. Recent research suggests that real-life exposure sources trigger stronger biological responses than laboratory-generated RF-EMF. However, there is a lack of research comparing the effects of these sources. This paper introduces a portable system for assessing and monitoring EMF exposure in urban areas. Employing a Software-Defined Radio (SDR) platform to ensure adaptability, the system incorporates two measurement configurations. The initial version concentrates on determining the average power within a 20 MHz Wi-Fi channel, whereas the subsequent configuration augments its functionality by introducing a frequency sweep. This sweep broadens the scrutinized bandwidth, thereby enriching the captured data content through the storage of spectrum sweeps corresponding to each average power value. These data can be used to create EMF profile maps based on individuals’ geographical coordinates. Compared to current limited-performance commercial exposimeters, the proposed system offers expanded capabilities by broadening the frequency bandwidth, georeferencing measurements, and storing data in an SQL database. Compared to high-performance commercial exposimeters, the major advantage of the system is its ability to detect short-term fluctuations in signal spectra and store the corresponding data for subsequent analysis.

ANALYSIS OF MECHANICAL POWER TRANSFORMATION PROCESSES DURING HARMONIC OSCILLATIONS OF DRIVES IN LOAD-LIFTING, TRANSPORTING AND VIBROFORMING CONCRETE MIXTURE MACHINES AND MECHANISMS

The purpose of the study is to detail the types of mechanical power during harmonic oscillations of drives in load-lifting, transporting and vibroforming concrete mixture machines and mechanisms. Due to the irreversibility of thermal energy, its derivative will take only positive values. However, derivatives can be taken from both potential and kinetic energy. But the most interesting case is the case of harmonic os-cillations in the specified machines and mechanisms drives, for which the derivatives (instantaneous power) are sign-changing functions, that fundamently distinguishes them from thermal power. The analogue of kinetic energy in electric engineering is magnetic field energy in inductor coil, potential energy analogue is capacitor’s electric field energy, and mechanical thermal energy is replaced by thermal energy, which is dissipated by the resistor. It is shown in this study that not only thermal power (with a positive sign) develops during load-lifting, transporting and vibroforming concrete mixture machines and mechanisms drivers mechanical oscillations , but also sign-changing reactive powers, which characterize the kinetic and potential energies inverse. Here, the active power is understood as the average value of the instantaneous power for half a period, and under reactive − amplitude value. The full mechanic power of machines and mechanisms drives, on the one hand, is described by the Pythagorean formula, and from the other − is equal to the product of the harmonic quantities effec-tive values. A feature of the complex representation is that when calculating the full power, one of the vectors that are multiplied must be conjugate. The representation about mechanical reactive, active and full power is a generalization of the corre-sponding consepts from electrical engineering, which is a manifestation of electro-mechanical dualism. Since in most machines and mechanisms the drives are mainly electromechanical, mechanical reactive power transforms into electrical reactive power of the network, thereby worsening the quality of electricity. Therefore, con-sideration of mechanical reactive power is of great importance.

FTTH NETWORK DISTURBANCE ANALYSIS BASED ON ATTENUATION AND RECEPTION POWER ON THE INDIHOME SINGKAWANG NETWORK

Optical fiber is a transmission medium that allows it to meet human needs to be able to transfer data faster because it uses light as a conductor. There is a damping problem in optical fiber, it needs to be accommodated so as to minimize the occurrence of attenuation in optical fiber. With this research, it can be known the magnitude of the value of a fiber optic transmission attenuation through the method of measuring attenuation values and receiving power at the customer's home using OPM, identifying fiber optic channel attenuation that affects the quality of internet services, and knowing the comparison of OPM measurement results with OT data reading. This study uses an analytical descriptive approach where the research will describe what it is about a variable that is processed, as well as the symptoms and conditions to be identified. So the results of the study can be obtained, namely, the amount of attenuation measured in the customer's home is influenced by the attenuation measured in ODP. Attenuation at ODP is small with an average optical power value of -18.39 dB, this makes attenuation in customers' homes, namely ONT, tend to be smaller with an average optical power value of -20.04 dB. There is an additional value of -1.65 dB per transmission. So it is known that the longer the cable used for fiber optic transmission, the greater the attenuation produced so that the optical power emitted by the sender will weaken along with the length of the cable. This is what will affect the quality of internet services.

Solar-Based Smartphone Charging Stations with Voltage, Current, and Power Monitoring

Renewable energy sources continue to be developed as alternative energy sources to reduce the use of fossil energy sources. One of them is a solar power plant that uses a light source from sunlight. For the public, electrical energy is useful to support work and communication activities such as using smartphones, but not many chargers are found in public places to charge smartphone batteries. It has designed and implemented a smartphone charging station to charge smartphone batteries using solar power. The smartphone battery charging on this smartphone charging station can display voltage, current, and power when charging the battery;this tool is equipped with an INA219 sensor, ATmega328 microcontroller, and solar power to make this tool look smart. The purpose of making this tool is to find out the working principle, voltage, current, and power and compare the charging time of the smartphone battery between the smartphone charging station and the manufacturer's charger. The working principle is that when this tool charges the smartphone battery, the INA219 sensor receives output value data in the form of current and voltage. Furthermore, the sensor sends a signal to the ATmega328 to be converted and displayed as data on the LCD so that users can see the output value. The test results of the tool, when charging a smartphone battery using Micro USB, showed the average values of voltage, current, and power, respectively, of 11.7 volts, 0.48 amperes, and 5.98 watts. USB Type C shows the average voltage, current, and power values of 11.33 volts, 0.71 amperes, and 8.37 watts, respectively. The comparison of the duration of battery charging time on the manufacturer's Micro USB with the smartphone charging station has a difference of 27 minutes; the comparison of the duration of the smartphone battery charging time using the manufacturer's USB Type C with the smartphone charging station has a difference of 22 minutes.