scholarly journals KONSENTRASI SEDIMEN SUSPENSI PADA BELOKAN 57° SALURAN TERBUKA

2018 ◽  
Author(s):  
Ady Purnama

Predicting the behavior of the flow in the channel turned quite important, because the channel has turned a fairly high level prone to water damage when compared with the straight line. A phenomenon that often occurs and causes kerugikan in turn channel is the sediment transport phenomena.The phenomenon that occurs in the channel turn can be detected by performing measurements directly in the field. For a case study of parent channel mataram, the research done by measurement of sediment concentration profiles using the tool opcon suspension. The study was conducted on curves that have the angle, α = 57 ° with r = 50 m. From the analysis of the measurements of the concentration of sediment suspensions carried out in an open channel with a bend 57 °, indicating that the concentration of sediment suspension had a trend which is almost equal to the entire face, ie the concentration of sediment suspension is increased toward the base line and decreasing toward the surface of the water with the trend of distribution more upright with values more uniform towards the water surface. In the transverse direction, the concentration of sediment suspension tends to increase toward the inside of the bend when passing through the initial turn, then decreases towards the inside of the bend as it passes through the middle of the turn, and again increased toward the inside of the bend as it passes through the final turn which resulted in the deposition on the inside of the turn ( inner bank) and erosion on the outer side of the bend (outer bank) on the basis of the channel. For the analysis of sediment suspension concentration field measurement results are compared with the analysis of the rouse equation and the equation tanaka-sugimoto show that enough measurement data can predict sediment concentration suspension on curves, although the angle and radius of the bend is varied. Suspension of sediment measurement data value is closer to the data analysis results rouse and tanaka-sugimoto. The results of the analysis of tanaka-sugimoto could provide better results than analysis rouse.

2018 ◽  
Author(s):  
Ady Purnama

Predicting the behavior of the flow in the channel bend quite important, because the channel bend a fairly high degree of cartilage against the destructive force of water when compared to a straight channel. Phenomena that may occur and cause detriment is the phenomenon of sediment transport that passes through the channel bend. The phenomenon that occurs in the channel bend can be detected by measuring the field directly. For a case study of the Irrigation Mataram, research done by the measurement of the concentration profiles of sediment transport using devices Opcon. The study was conducted at a locations with the curves that have angles, α = 55° with Radius = 50 m. From the analysis of the measurement of velocity flow and sediment concentration suspensions were performed at the curves that have angles, α = 55° with Radius = 50 m, indicating that the minimum velocity for trend occurs near the base and the increase in size towards the surface of the stream. Flow velocity acceleration and deceleration experienced when through the turn, which increases the velocity flow in the bend side (inner bank) when passing the initial curves and velocity decreases as it passes through the opposite end of the turn and descent speed on the outside of the bend (outer bank) when passing through curves and initial experience increase in the inside of the turn as it passes through the end of the turn. The concentration of sediment suspensions have almost the same trend for the entire face, the concentration of sediment suspension increases towards the base line and decreased with the trend towards the surface of the water distribution more upright with a more uniform rate towards the surface of the water. In the transverse direction, the concentration of sediment suspension tends to increase towards the inner side of the bend when passing through the initial turn, and then decreases towards the inner side of the bend as it passes through the middle of the turn and increased again towards the inside of the turn as it passes through the final turn which resulted in deposition on the inside of the turn (inner bank) and erosion on the outside of the bend (outer bank) at the base of the channel. For analysis of the consentration of sediment suspension field measurement results are compared with the analysis of the Rouse equation and equation-Sugimoto Tanaka showed that the measurement data can reasonably predict the consentration of sediment suspension on curves, although the angle and bend radius varies. Measurement data of suspended sediment consentration approaching the value of data analysis results Rouse and Tanaka-Sugimoto.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4512
Author(s):  
Kerstin Friebe ◽  
Frank Jenau

Partial discharge measurement is part of the monitoring of equipment in power engineering systems. It provides important information about the condition of the equipment and in particular the condition of the insulation components. This information serves to take necessary preventive measures at an early stage to avoid failures of the affected energy system and thus ensure a high level of energy supply security. Possible causes of partial discharges in energy technology equipment include high field strengths at edges with small radii or defects within insulation materials itself. Depending on the location and extent of the occurrence, partial discharge events may cause lasting damage to components of equipment. In order to be able to interpret the measurement results of partial discharge monitoring with regard to the exact cause and, if necessary, to evaluate them automatically, a precise understanding of the physical phenomena that occur during a partial discharge is necessary. The physical replication of a partial discharge pulse helps to better understand, evaluate, and interpret measurement results and thus create a synergy between measurement data and model-based results.


Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1265 ◽  
Author(s):  
Johanna Geis-Schroer ◽  
Sebastian Hubschneider ◽  
Lukas Held ◽  
Frederik Gielnik ◽  
Michael Armbruster ◽  
...  

In this contribution, measurement data of phase, neutral, and ground currents from real low voltage (LV) feeders in Germany is presented and analyzed. The data obtained is used to review and evaluate common modeling approaches for LV systems. An alternative modeling approach for detailed cable and ground modeling, which allows for the consideration of typical German LV earthing conditions and asymmetrical cable design, is proposed. Further, analytical calculation methods for model parameters are described and compared to laboratory measurement results of real LV cables. The models are then evaluated in terms of parameter sensitivity and parameter relevance, focusing on the influence of conventionally performed simplifications, such as neglecting house junction cables, shunt admittances, or temperature dependencies. By comparing measurement data from a real LV feeder to simulation results, the proposed modeling approach is validated.


Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 41
Author(s):  
Tim Jurisch ◽  
Stefan Cantré ◽  
Fokke Saathoff

A variety of studies recently proved the applicability of different dried, fine-grained dredged materials as replacement material for erosion-resistant sea dike covers. In Rostock, Germany, a large-scale field experiment was conducted, in which different dredged materials were tested with regard to installation technology, stability, turf development, infiltration, and erosion resistance. The infiltration experiments to study the development of a seepage line in the dike body showed unexpected measurement results. Due to the high complexity of the problem, standard geo-hydraulic models proved to be unable to analyze these results. Therefore, different methods of inverse infiltration modeling were applied, such as the parameter estimation tool (PEST) and the AMALGAM algorithm. In the paper, the two approaches are compared and discussed. A sensitivity analysis proved the presumption of a non-linear model behavior for the infiltration problem and the Eigenvalue ratio indicates that the dike infiltration is an ill-posed problem. Although this complicates the inverse modeling (e.g., termination in local minima), parameter sets close to an optimum were found with both the PEST and the AMALGAM algorithms. Together with the field measurement data, this information supports the rating of the effective material properties of the applied dredged materials used as dike cover material.


2021 ◽  
Vol 180 ◽  
pp. 108107
Author(s):  
Guillaume Fromant ◽  
Nicolas Le Dantec ◽  
Yannick Perrot ◽  
France Floc'h ◽  
Anne Lebourges-Dhaussy ◽  
...  

2017 ◽  
Vol 6 (2) ◽  
pp. 279-284 ◽  
Author(s):  
László Hegymegi ◽  
János Szöllősy ◽  
Csaba Hegymegi ◽  
Ádám Domján

Abstract. Geomagnetic observatories use classical theodolites equipped with single-axis flux-gate magnetometers known as declination–inclination magnetometers (DIM) to determine absolute values of declination and inclination angles. This instrument and the measurement method are very reliable but need a lot of handwork and experience. The authors developed and built a non-magnetic theodolite which gives all measurement data in digital form. Use of this instrument significantly decreases the possibility of observation errors and minimises handwork. The new instrument is presented in this paper together with first measurement results in comparison to the classical DIM.


Author(s):  
Mochamad Zaeynuri Setiawan ◽  
Fachrudin Hunaini ◽  
Mohamad Mukhsim

The phenomenon that often arises in a substation is the problem of partial discharge in outgoing cable insulation. Partial discharge is a jump of positive and negative ions that are not supposed to meet so that it can cause a spark jump. If a partial discharge is left too long it can cause insulation failure, the sound of snakes like hissing and the most can cause a flashover on the outgoing cable. Then a partial discharge detection prototype was made in the cable insulation in order to anticipate the isolation interference in the outgoing cable. Can simplify the work of substation operators to check the reliability of insulation on the outgoing side of each cubicle. So it was compiled as a method for measuring sound waves caused by partial discharge in the process of measuring using a microphone sensor, the Arduino Mega 2560 module as a microcontroller, the LCD TFT as a monitoring and the MicroSD card module as its storage. The microphone sensor is a sensor that has a high sensitivity to sound, has 2 analog and digital readings, and is easily designed with a microcontroller. Basically the unit of measure measured at partial discharge is Decibels. The results of the prototype can be applied to the cubicle and the way it works is to match the prototype to the outgoing cubicle cable then measure from the cable boots connector to the bottom of the outgoing cable with a distance of 1 meter. Then the measurement results will be monitored on the TFT LCD screen in the form of measurement results, graphs and categories on partial discharge. In this design the measurement data made by the microphone can be stored with microSD so that it can make an evaluation of partial discharge handling in outgoing cable insulation.


Author(s):  
Timon Hummel ◽  
Claude Coatantiec ◽  
Xavier Gnata ◽  
Tobias Lamour ◽  
Rémi Rivière ◽  
...  

AbstractThe measurement accuracy of recent and future space-based imaging spectrometers with a high spectral and spatial resolution suffer from the inhomogeneity of the radiances of the observed Earth scene. The Instrument Spectral Response Function (ISRF) is distorted due to the inhomogeneous illumination from scene heterogeneity. This gives rise to a pseudo-random error on the measured spectra. In order to assess the spectral stability of the spectrograph, stringent requirements are typically defined on the ISRF such as shape knowledge and the stability of the centroid position of the spectral sample. The high level of spectral accuracy is particularly crucial for missions quantifying small variations in the total column of well-mixed trace gases like $$\hbox {CO}_{2}$$ CO 2 . In the framework of the $$\hbox {CO}_{2}$$ CO 2 Monitoring Mission (CO2M) industrial feasibility study (Phase A/B1 study), we investigated a new slit design called 2D-Slit Homogenizer (2DSH). This new concept aims to reduce the Earth scene contrast entering the instrument. The 2DSH is based on optical fibre waveguides assembled in a bundle, which scramble the light in across-track (ACT) and along-track (ALT) direction. A single fibre core dimension in ALT defines the spectral extent of the slit and the dimension in ACT represents the spatial sample of the instrument. The full swath is given by the total size of the adjoined fibres in ACT direction. In this work, we provide experimental measurement data on the stability of representative rectangular core shaped fibre as well as a preliminary pre-development of a 2DSH fibre bundle. In our study, the slit concept has demonstrated significant performance gains in the stability of the ISRF for several extreme high-contrast Earth scenes, achieving a shape stability of $$<0.5{\%}$$ < 0.5 % and a centroid stability of $$<0.25 \ \text {pm}$$ < 0.25 pm (NIR). Given this unprecedented ISRF stabilization, we conclude that the 2DSH concept efficiently desensitizes the instrument for radiometric and spectral errors with respect to the heterogeneity of the Earth scene radiance.


Author(s):  
Dodi Sofyan Arief ◽  
◽  
Eko Jadmiko ◽  
Adhy Prayitno ◽  
Muftil Badri ◽  
...  

Dial indicator is a comparison device usually used in industrial activities, especially in production. To make measurements at this time must be supported by technology that can facilitate operators when using it and when analyzing measurement results. Involving the programme and microcontroller are a solution to developing in roundness measurement, and then the results can be more accurate or thorough between the readable values read from the measuring instrument with the actual value of varying the amount of data. Roundness application is a program that can input measurement data automatically and can do calculations directly. Then, it can display a reference circle, a table that calculates the values of X, Y, R, X’, Y’, R’, Roundness Deviation, Run out Concentricity or a shift in the center point and also the center point shift or Theta. In measuring roundness, the test object is used the Standard Mandrel which has been certified by PT. Global Quality Indonesia, by determining three points or positions, namely in the first position the amount of data is 180, in the second position the amount of data is 90 and in the third position, the amount of data is 60 with a rotating speed of 15 mm/s. The results of the reference circle can be seen in each calculation in each position, in the second position the roundness deviation values are approaching of the Mandrel.


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