Physics Students’ Conceptual Understanding of Electricity and Magnetism in Nine Years Basic Education in Rwanda

We investigate students’ misconceptions in electrostatics, direct current (DC) and magnetism which are important in electricity and magnetism. We developed and administered a multiple-choice questionnaire test to reveal students’ misconceptions related to charged bodies, lightning, electric fields, electric potential, forces, DC resistive electric circuits and magnets. This test aimed at obtaining quantitative information about misconceptions and was administered to 380 senior two students from Nine Year Basic Education (9YBE) Schools. The selected students have some experience with the new Rwandan secondary physics Competence Based Curriculum (CBC) that is currently under implementation. We find that senior two students have several common misconceptions related to these concepts. The data indicate that although students have some backgrounds on the subject matter, they still seem to believe that if the two charges are separated by a distance, a large-charged object exerts a greater force of attraction or repulsion on the small one. Considerable number of participated students held the misconception of considering current consumption in the resistor/bulb or the electrical devices in the circuits. They also believed that the battery was a continuous current source. The findings also revealed that students held a misconception that a bar magnet when broken into pieces, it is demagnetized. Moreover, a considerable number of participants hold the misconception that all metals are attracted by a magnet. Our study also revealed some of the statistically significant differences in terms of either gender or location of schools for some items.

Modelling, Simulation, and Implementation of Effective Controller for KY Stepping Up Converter

This paper studies on a new Hybrid Posicast Control (HPC) for Fundamental KY Boost Converter (FKYBC) worked in Continuous Current Mode (CCM). Posicast is a feed-forward compensator. It reduces the overshoot in the step result of the flippantly damped plant. But the conventional controller approach is sensitive owing to the changes in the natural frequency. So, as to reduce this undesirable sensitivity and load potential control of FKYBC, a HPC is designed in this article. Structure of HPC is posicast with feedback loop. The independent computational time delay is the main design function of the posicast. The enactment of the FKYBC with HPC is confirmed at various operating regions by making the MATLAB/Simulink and experimental model. The posicast function values are implemented in Arduino Uno-ATmega328P microcontroller. The results of new HPC have produced minimal noise in control signal in comparison with traditional PID control.

Gambaran Nyeri Pada Osteoartritis Lutut Setelah Pemberian Intervensi Dengan Modalitas Ultrasound: Literature Review

Knee Osteoarthritis is characterized by pain, deformity, and limitation of movement. To reduce pain in patients with knee osteoarthritis, interventions can be given, one of which is ultrasound with continuous current. Determine the description of pain in knee osteoarthritis after intervention with ultrasound modality. PICO writing method is used as the selection of articles in this literature review research. This article was obtained from PubMed and NCBI with predetermined inclusion and exclusion criteria. The measuring instrument used in the literature review is the visual analogue scale (VAS). The results of the literature review analysis in these five articles showed that pain reduction before the procedure were 6.79 and after the procedure were 3.43 with a difference of 3.36. From the results of the literature review of these five articles, it shows that there is a change in the depiction of pain in knee osteoarthritis patients after being given ultrasound intervention. Keywords: Knee Osteoarthritis; Visual Analogue Scale (VAS), Ultrasound Abstrak Osteortritis lutut ditandai dengan nyeri, deformitas, dan hambatan gerak. Untuk menurunkan nyeri pada pasien osteoartritis lutut dapat diberikan intervensi salah satunya adalah ultrasound dengan arus continuous. Mengetahui gambaran nyeri pada osteoartritis lutut setelah pemberian intervensi dengan modalitas ultrasound. Pemilihan artikel pada penelitian literature review ini menggunakan PICO. Artikel ini didapatkan dari PubMed dan NCBI dengan kriteria inklusi dan kriteria ekslusi yang telah ditentukan. Alat ukur yang digunakan dalam literature review adalah visual analogue scale (VAS). Hasil analisis literature review pada kelima artikel ini menunjukkan bahwa penurunan nyeri sebelum tindakan 6,79 dan sesudah tindakan 3,43 dengan selisih 3,36. Dari hasil literature review kelima artikel ini menunjukkan bahwa ada perubahan gambaran nyeri pada pasien osteoartritis lutut sesudah diberikan intervensi ultrasound. Kata Kunci : Osteoartritis Lutut, Visual Analgogue Scale (VAS), Ultrasound

Gambaran Nyeri Pada Osteoartritis Lutut Setelah Pemberian Intervensi Dengan Modalitas Ultrasound : Literature Review

Knee Osteoarthritis is characterized by pain, deformity, and limitation of movement. To reduce pain in patients with knee osteoarthritis, interventions can be given, one of which is ultrasound with continuous current.. Determine the description of pain in knee osteoarthritis after intervention with ultrasound modality. PICO writing method is used as the selection of articles in this literature review research. This article was obtained from PubMed and NCBI with predetermined inclusion and exclusion criteria. The measuring instrument used in the literature review is the visual analogue scale (VAS). The results of the literature review analysis in these five articles showed that pain reduction before the procedure were 6.79 and after the procedure were 3.43 with a difference of 3.36. From the results of the literature review of these five articles, it shows that there is a change in the depiction of pain in knee osteoarthritis patients after being given ultrasound intervention. Keywords: Knee Osteoarthritis; Visual Analogue Scale (VAS), Ultrasound Abstrak Osteortritis lutut ditandai dengan nyeri, deformitas, dan hambatan gerak. Untuk menurunkan nyeri pada pasien osteoartritis lutut dapat diberikan intervensi salah satunya adalah ultrasound dengan arus continuous. Mengetahui gambaran nyeri pada osteoartritis lutut setelah pemberian intervensi dengan modalitas ultrasound. Pemilihan artikel pada penelitian literature review ini menggunakan PICO. Artikel ini didapatkan dari PubMed dan NCBI dengan kriteria inklusi dan kriteria ekslusi yang telah ditentukan. Alat ukur yang digunakan dalam literature review adalah visual analogue scale (VAS). Hasil analisis literature review pada kelima artikel ini menunjukkan bahwa penurunan nyeri sebelum tindakan 6,79 dan sesudah tindakan 3,43 dengan selisih 3,36. Dari hasil literature review kelima artikel ini menunjukkan bahwa ada perubahan gambaran nyeri pada pasien osteoartritis lutut sesudah diberikan intervensi ultrasound. Kata Kunci : Osteoartritis Lutut, Visual Analgogue Scale (VAS), Ultrasound

Electrochromism of Viologen/Polymer Composite: From Gel to Insulating Bulk for High-Voltage Applications

Power equipment operates under high voltages, inducing space charge accumulation on the surface of key insulating structures, which increases the risk of discharge/breakdown and the possibility of maintenance workers experiencing electric shock accidents. Hence, a visualized non-equipment space charge detection method is of great demand in the power industry. Typical electrochromic phenomenon is based on redox of the material, triggered by a voltage smaller than 5 V with a continuous current in μA~mA level, which is not applicable to high electric fields above 106 V/m with pA~nA operation current in power equipment. Until now, no naked-eye observation technique has been realized for space charge detection to ensure the operation of power systems as well as the safety of maintenance workers. In this work, a viologen/poly(vinylidene fluoride-co-hexafluoropropylene)(P(VDF–HFP)) composite is investigated from gel to insulating bulk configurations to achieve high-voltage electrical-insulating electrochromism. The results show that viologen/P(VDF–HFP) composite bulk can withstand high electric fields at the 107 V/m level, and its electrochromism is triggered by space charges. This electrochromism phenomenon can be visually extended by increasing viologen content towards 5 wt.% and shows a positive response to voltage amplitude and application duration. As viologen/P(VDF–HFP) composite bulk exhibits a typical electrical insulating performance, it could be attached to the surface of insulating structures or clamped between metal and insulating materials as a space charge accumulation indicator in high-voltage power equipment.

Calculation Method of Allowable Continuous Current for Direct Burial Laying HVDC Underground Cable

The calculation of the continuous allowable current of an underground cable is determined by various characteristics. To calculate the allowable current in cables with alternating magnetic fields such as AC, special phenomena such as the proximity effect and skin effect must be applied. However, there are no standards or research related to the calculation of the continuous allowable current of a DC power cable that does not have an alternating magnetic field. In this paper, a quantitative DC cable continuous allowable current calculation formula of direct burial laying was derived by applying the existing AC cable continuous allowable current calculation method to the DC system. We developed a calculation tool that can calculate the continuous allowable current of DC cables using the derived formula. Assuming the cable conditions (cable specification, laying conditions, soil characteristics, arrangement, and number of strands, etc.), a continuous allowable current simulation of DC cables was performed. In addition, the level of contribution to the continuous allowable current value was analyzed by classifying the parameter categories into major and minor factors in the order of influence on the allowable current among the determined calculated parameters. As a result, the effectiveness of the DC cable continuous allowable current calculation tool derived by performing the allowable current calculation simulation was evaluated, and the allowable current calculation method of the HVDC cable was established.

Comparison of electronic load using linear regulator and boost converter

<span lang="EN-US">Direct current (DC) electronic load is a useful equipment for testing the electrical system. It can emulate various load at a high rating. The electronic load requires a power converter to operate and a linear regulator is a common option. Nonetheless, it is hard to control due to the temperature variation. This paper proposed a DC electronic load using the boost converter. The proposed electronic load operates in the continuous current mode and control using the integral controller. The electronic load using the boost converter is compared with the electronic load using the linear regulator. The results show that the boost converter able to operate as an electronic load with an error lower than 0.5% and response time lower than 13 ms.</span>

An IGSVL and SGSVL FinFET 6T SRAM-based novel power reduction technique

The development of future portable integrated circuits will need to focus on power optimization. As the consequence of continuous current flow, the rise in leakage current in VLSI circuits has recently emerged as a significant issue to solve. It is feasible to reduce the threshold voltage while still decreasing leakage, as long as you don't compromise the other design objectives. An integrated circuit's ability to operate at low power will be more essential in the future. Using current scaling technologies, it seems that Fin FET may potentially be a more practical choice for bulk CMOS. Fin FETs are said to be better than ordinary CMOS transistors since they are double gated. For minimizing power usage, you should use twin gates that are driven simultaneously or independently. In this research, T-Spice is used to install Fin FETs in 45nm SRAM cells that were produced using SRAM cells made in various process technologies to reduce leakage in the circuits under discussion.

Compact TSA with Anti-Spiral Shape and Lumped Resistors for UWB Applications

A novel compact tapered-slot-fed antenna (TSA) with anti-spiral shape and lumped resistors is presented for ultra-wideband (UWB) applications. Unique coplanar waveguide (CPW) to coplanar strip (CPS) feeding structure and exponential slot are designed to ensure the continuous current propagation and good impedance matching. With a pair of anti-spiral-shaped structure loadings at the end of the antenna, the radiation performance in lower operating band can be enhanced obviously. The typical resistor loading technique is applied to improve the time domain characteristics and expand the bandwidth. The fabricated prototype of this proposed antenna with a size of 53 × 63.5 mm2 was measured to confirm simulated results. The proposed antenna has S11 less than −10 dB in the range of 1.2–9.8 GHz, and the group delay result is only 0.4 ns. These findings indicate the proposed antenna can be taken as a promising candidate in UWB communication field.