UM Shaper Command Inputs for CRONE Control: Application on a DC Motor Bench

This study proposes an approach to synthesize a three-impulse sequence input shaper with a negative impulse, known as Unity Magnitude (UM) shaper. The corresponding analytic model has been already achieved for undamped and low-damped systems. In this paper, the analytic design of UM shaper is demonstrated for the generalized case of damped systems for both types: integer and fractional orders. Hence, the UM shaper model has been designed for second-order systems with damped dynamics, associating a graphical fitting and an analytical procedure; then, it has been extended to explicit fractional derivative systems. Moreover, the feasibility and the effectiveness of the proposed on-off profile prefilter applied on a second-generation controller have been substantiated by experimental results on an instrumented DC motor bench.

On the Characterisations of the Impulse Breakdown in High Resistivity Soils by Field Testing

This paper presents experimental results of high-current impulse tests on six ground electrode configurations. A high impulse current generator is employed to inject different magnitudes of current into these rod electrodes, under both positive and negative impulse polarities. The effect of increasing the number of rod electrodes, hence the resistance at DC or steady-state (RDC), on the impulse response of ground electrodes is analysed. From the analysis of the results, it was found that the larger the size of rod electrodes, the less current-dependent Zimpulse becomes. The percentage of reduction of impulse impedance, Zimpulse from its steady state, and RDC values are found to be independent of impulse polarity. However, as the voltage magnitudes were increased, an occurrence of breakdown was seen, with higher breakdown voltage seen in negative impulse polarity in comparison to positive impulse polarity. Relatively, the higher the breakdown voltage is, seen in the ground electrodes subjected to negative polarity, the faster the time to breakdown is.

Sustainable Energy as a Tool to Reduce the Risk of the Quality of Life Decrease

At present, sustainable energy based on new technologies and dissipative structures is considered as the main tool for combating climate change and reducing anthropogenic impact on the environment. At the same time, the development of dynamic energy that creates flexible and adaptive economic and energy systems is going to become the main factor to reduce negative impact of energy insecurity on the quality of life of the population. This article analyzes the mechanism of propagation of the negative impulse arising from the implementation of threats to energy security, which, passing from element to element of the country's economic system, including energy system, leads to a decrease in the quality of life of the population. Within the framework of the economic system, there is either attenuation or strengthening of the negative initial impulse triggered by the implementation of a particular threat to energy security. In the course of the study, we identified the factors that amplify the negative effect of the passage of an impulse in different segments of the national economy, as well as factors associated with the development of sustainable energy, which contribute to the attenuation of the negative impulse and ensure an increase in the quality of life of the population.

Effect of Impulse Polarity on a New Grounding Device with Spike Rods (GDSR)

The characterizations of grounding systems subjected to high impulse conditions are known to be dependent on the polarity, current to peak time and discharge time, as well as the electrical properties of the soil, and the grounding electrodes themselves. It is therefore important to investigate the behavior of grounding systems under high impulse conditions under negative impulse polarity, and compare it with positive impulse polarity results. Experimental test results for the same grounding systems installed with various earth electrodes at several sites under positive impulse polarity have previously been presented. In comparison, this paper presents the results of negative impulse polarity injected on the same grounding systems. It is found that a significant difference between positive and negative impulse polarities is observed for the grounding systems installed at high soil resistivity.

Understanding the Mechanics of Blast Pressure Waves Inside a Shock-Tube: Effects of Geometry Optimization on the Blast Profile

While many theoretical and numerical studies have been carried out to study blast induced traumatic brain injury (bTBI), validation of simulation results is still a concern due to moral issues and experimental constraints. Shock-tubes are one of the major means for replicating blast waves in a controlled medium. North Dakota State University Shock-tube (NDSUST) has been designed to simulate the blast shockwaves in an attempt to study and investigate bTBI. However, accurate replication of a blast profile in terms of the impulse and overpressure is highly dependent on the geometrical features of the shock-tube. To this end, numerical methods such as computational fluid dynamic (CFD) analysis can help to evaluate and increase the efficiency of the current shock-tubes. The NDSUST contains three major parts, namely, driver (the high pressure container), driven cone, and the chamber to setup the head model. The driver and driven cone are separated by layers of Mylar membrane. Shockwaves are defined by three pressure-time characteristics; positive phase (positive impulse), negative phase (negative impulse), and maximum pressure (overpressure). While the current NDSUST simulated most shockwave characteristics accurately, the negative impulse was observed to be considerably long. The diameter of Mylar membrane interface, the volume of the deriver, and the chamber room cross-section connected to the driven cone, were considered as possible parameters affecting the efficiency of the shock-tube. Accordingly, NDSUST was modeled in ANSYS CFX using its actual dimensions. A transient CFD analysis was carried out using ANSYS CFX to simulate the turbulent, supersonic, and compressible flow upon rupture of the Mylar membrane in order to study the pressure wave propagation inside the shock-tube. No-slip boundary conditions were chosen for the shock-tube walls. Driver and driven sections were considered as two separate domains connected using an interface. The shockwave was generated by setting the driver and driven sections at high and low pressures, respectively and running the simulation for a total time of 1 second. The primary results revealed that the current cross-section at the interface of the driven cone and the square chamber caused the pressure disruption (pressure oscillation) upon entrance of the pressure waves into the chamber room. In addition, it was concluded that the driver volume would affect the negative impulse’s duration and the negative peak pressure.

RESILIENSI PADA REMAJA PUTRI YANG MENGALAMI KEHAMILAN TIDAK DIINGINKAN AKIBAT KEKERASAN SEKSUAL

ABSTRACT This study aims to provide an overview of resilience in teenagers girl who experience unwanted pregnancy due to sexual abuse. The approach used in this study is a qualitative approach with a qualitative case study approach. Data collection techniques used were interviews, observation and documentation. Data were analyzed using qualitative data analysis techniques and techniques of data validity checks using triangulation.These results indicate that both the resilience so that the subject has the ability to positively adapt to the event of unwanted pregnancy due to sexual abuse. Subject I adapt to calm down and think over the matter while subject II adapting to talk to someone nearby. Both subjects also have a seventh aspect of building resilience with the capability of different quality. The subject I is better to regulate and control the negative impulse that is felt while subject II more visible sense of optimism and efficacy of the problem itself. The results also showed that support from the nearest such as family, friends, is one of the most influential factor on the development of resilience both subjects. Keywords: Resilience, teenagers girl, unwanted pregnancy, sexual abuse

Preparation of Three Types of Transformer Oil-Based Nanofluids and Comparative Study on the Effect of Nanoparticle Concentrations on Insulating Property of Transformer Oil

Nanofluids have the potential to become the alternatives of conventional transformer oil for their exquisite electrical and thermal properties. Three kinds of nanoparticles with distinct conductivities, namely, nonconductive nanoparticle Al2O3, conductive nanoparticle Fe3O4, and semiconductive nanoparticle TiO2, with different concentrations from 5% to 40% w/v were selected and suspended into transformer oil to develop nanofluids. The lightening impulse breakdown strengths of the oil samples with and without nanoparticles were measured according to IEC standard methods. The positive impulse breakdown strength indicated that breakdown strength is first increased up to the maximum value at certain concentration and then starts decreasing. The results of negative impulse breakdown manifested that the breakdown voltages of nanofluids with different concentrations were less than the breakdown voltage of pure transformer oil. Different effect mechanisms of dielectric and conductive nanoparticles were also used to describe the difference among three prepared nanofluids.