Physically Based Compact Model for Segmented a-Si:H n-i-p Photodiodes

2008 ◽  
Vol 1066 ◽  
Author(s):  
Jeff Hsin Chang ◽  
Timothy Tredwell ◽  
Gregory Heiler ◽  
Yuri Vygranenko ◽  
Denis Striakhilev ◽  
...  

ABSTRACTHydrogenated amorphous silicon (a–Si:H) n–i–p photodiodes are used as pixel sensor elements in large-area flat-panel detectors for medical imaging diagnostics. Accurate model of the sensor plays an imperative role in determining the performances of the detector systems as well as ascertaining design issues prior to production. This work presents the formulation of a compact model for segmented a–Si:H n–i–p photodiodes suitable for circuit-level simulation. The underlining equations of the model are based on device physics where the parameters are extracted from pertinent measurement results of previously fabricated a–Si:H n–i–p photodiodes. Furthermore, the implemented model allows photoresponse simulation with the addition of an external current source. Results of the simulation demonstrated excellent matching with measurement data for different photodiode sizes at various temperatures. The model is implemented in Verilog-A and simulated under Cadence Virtuoso design environment using device geometry and extracted parameters as inputs. The model formulation and parameter extraction process, as well as measurements and simulation results are presented.

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.


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.


2010 ◽  
Vol 28 (9) ◽  
pp. 1795-1805 ◽  
Author(s):  
S. A. McLay ◽  
C. D. Beggan

Abstract. A physically-based technique for interpolating external magnetic field disturbances across large spatial areas can be achieved with the Spherical Elementary Current System (SECS) method using data from ground-based magnetic observatories. The SECS method represents complex electrical current systems as a simple set of equivalent currents placed at a specific height in the ionosphere. The magnetic field recorded at observatories can be used to invert for the electrical currents, which can subsequently be employed to interpolate or extrapolate the magnetic field across a large area. We show that, in addition to the ionospheric currents, inverting for induced subsurface current systems can result in strong improvements to the estimate of the interpolated magnetic field. We investigate the application of the SECS method at mid- to high geomagnetic latitudes using a series of observatory networks to test the performance of the external field interpolation over large distances. We demonstrate that relatively few observatories are required to produce an estimate that is better than either assuming no external field change or interpolation using latitudinal weighting of data from two other observatories.


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):  
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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