Sine Square Research Articles

Enriched vibrational resonance in certain discrete systems

We wish to report the occurrence of vibrational resonance in certain discrete systems like sine square map and sine circle map, in a unique fashion, comprising of multiple resonant peaks which pave the way for enrichment. As the systems of our choice are capable of exhibiting vibrational resonance behaviour unlike the earlier reports, they are taken for investigation and the necessary numerical and analytical results are presented. Further, we study the effect of external forcing on various attractors of these systems with appropriate bifurcation and Lyapunov exponent diagrams.

Masticatory function induced changes, at subnanostructural level, in proteins and mineral at the resin–dentine interface

ObjectiveThis study evaluated the ability of different in vitro mechanical loading tests to promote new mineral formation at the bonded dentine interfaces created with a two-step self-etching resin adhesive. MethodologyRestored teeth were divided in the following groups: (1) unloaded, load cycling with (2) sine waveform, (3) square waveform, and hold waveform for (4) 24h, and (5) 72h. Raman spectroscopy and cluster analysis were used to assess the resin–dentine interface. ResultsMechanical loading in CSEB-treated samples promoted a generalized increase of relative presence of minerals and ratio of phosphate peaks, except in square waveform, where the nature of collagen resulted damaged. Crystallinity of carbonate was higher than phosphate. The organic component showed, in general terms, an increase in crosslinking. Molecular orientation (α-helices) peaks augmented in all tests. Pentosidine vibration increases in all tests, except in hold 72h. Ratios amide I and II/CH2 incremented, in general. Non uniform parameters of Bis-GMA and adhesive penetration were encountered, as both increased at the bottom of the hybrid layer when loading square and hold 72h were applied. SignificanceFunctional remineralisation at the resin–dentine interface was attained after in vitro mechanical stimuli application. When loading in square waveform, the lowest vibrations to favor remineralisation were attained.

Design of a Functional Signal Generator Based on MAX038 and Microcontroller

Based on SCM STC89C52 and MAX038, a function signal generator for generating a frequency and amplitude can be programmed to adjust the sine wave, square wave and triangular wave signal. MAX038 function generator with a small amount of peripheral devices are responsible for generating waveforms, which then are input into the LM6361 wideband voltage amplifier and a power amplifier is output. Master STC89C52 is responsible for selecting and managing the waveform types, frequency adjustment, output amplitude adjustment, LCD, and keyboard work of each module operation.

“Tone deaf”— The touch based ear-training game

Inspired by the color matching game “Colorblind” by ChewSoft, Tone Deaf is the new game that challenges players to match the pitch and timbre of a note by touching the screen to draw a single cycle of the waveform. The shape of the waveform is then used to determine the appropriate harmonics and their phases, while the length of the cycle determines the frequency. Players will progress through multiple levels of difficulty, starting with simple waveforms such as sine waves, sawtooth waves, and square waves, and finally emulating the complex patterns of instruments such as the piano, trumpet, and violin.

A Study on the Characteristics of a Vibrator Using Flat PCB-Coil

In this study, we developed and evaluateda vibrator using a flat PCB-coil. The flat PCB-coil vibrator was fabricated on a printed circuit board using and etching process. The spiral pattern was etched on a fiberglass cloth with an epoxy resin. To evaluatethe flat PCB-coil vibrator, we generated a sine wave, saw-tooth, and square wave through a custom made wave generator and amplified the waveforms using a power amplifier. A three-axis accelerometer was used to evaluate the performance of the developed vibrator. Even though the developed vibrator is simple, it has a wide range of vibration frequency (50~500 Hz) and vibration amplitude (0~5 V). The vibration amplitude does not change due to frequency change. It is expected that the developed vibrator can be used in a wide variety of applications such as in a tactile stimulator, in elastography, energy harvesting, and in a cooling system.

English

This paper presents a detailed derivation of a permanent magnet synchronous motor, which may be used as the electric power train for the simulation of a hybrid electric vehicle. A torque tracking control of the permanent magnet synchronous motor is developed by using an adaptive proportional-integral-derivative controller. Several tests such as step function, saw tooth function, sine wave function and square wave function were used in order to examine the performance of the proposed control structure. The effectiveness of the proposed controller was verified and compared with the same system under a PID controller and the desired control. The result of the observations shows that the proposed control structure proves to be effective in tracking the desired torque with a good response. The findings of this study will be considered in the design, optimisation and experimentation of series hybrid electric vehicle.

TRANSCRANIAL MAGNETIC STIMULATION WITH APPLIED MULTISTEP DIRECT CURRENT GRAFTING

The controlling method for high-voltage pulse form or pulse parameter is extremely important in high speed switching technique. Function generation can repeatedly make various forms and widths of pulse waves such as low-voltage sine wave, square wave, and sawtooth wave. Waveform control is not easy when voltage exceeds a certain amount of kVs. Pulse forming network (PFN) or pulse forming line (PFL) has been used so far along with trigger gap, rail gap, semiconductor switch, ignitron, cyratron, and autocompression switch, which are used as switching device. For PFN, multistep LC circuit is introduced to widen the pulse width, and for PFL, a method to lengthen the charging line is adopted. These methods are difficult to control because a large number of devices are used, and the devices are getting bigger in terms of size. In order to compensate this weakness, the researchers of this study made self-stimulating pulse forms with various pulse widths by actively engrafting the low-voltage two-step or four-step circuits with the AVR one-chip microprocessor technology, which is widely used for two-step or four-step electric network recently with low price.

Changes in the dynamics of two-dimensional maps by external forcing

Abstract We investigate changes in periodicity, and even its suppression, by external periodic forcing in different two-dimensional maps, namely the Henon map and the sine square map. By varying the amplitude of a periodic forcing with a fixed angular frequency, we show through numerical simulations in parameter-spaces that changes in periodicity may take place. We also show that windows of periodicity embedded in a chaotic region may be totally suppressed.

입력파형에 따른 PZT 바이몰프 진동자의 출력특성

The aim of this study is to research maximum harvesting energy by the optimal input wave condition. The voltage characteristics of the PZT bimorph were investigated in terms of the sine wave, triangle wave and square wave according to frequency range 0~70Hz. It was found that the square wave compared with a triangular wave or square wave was showed the higher output energy. PZT bimorph was mechanically vibrated by solenoid coil experiments, which revealed two voltage peak mode according to frequency. Maximum voltage at second vibration frequency 28Hz demonstrated that the generated DC voltage was proportional to the tip displacement of the bimorph and the phase difference between the input frequency and bimorph vibration frequency was 90 degree. It was expected that optimized design to harvest a much higher energy level from lower frequency vibrations.

Design and Implementation of Digital Signal Generator Based on LPC2132

A design method of the digital signal generator, based on LPC2132 as the master control chip, is introduced in this paper. The system has used of a chip of the direct digital frequency synthesizer (DDS) and a complex programmable logic device(CPLD) to produce the sine wave, square wave and triangle wave, and has designed circuits of analog signal amplification and gain control. Realized the switch of different signal through the keyboard, it is a new kind of the digital signal source, which has performances including stabilizing waveform, higher precision, adjustable amplitude and frequency on the permitted scope.

Conopeptide ρ-TIA Defines a New Allosteric Site on the Extracellular Surface of the α1B-Adrenoceptor

The G protein-coupled receptor (GPCR) superfamily is an important drug target that includes over 1000 membrane receptors that functionally couple extracellular stimuli to intracellular effectors. Despite the potential of extracellular surface (ECS) residues in GPCRs to interact with subtype-specific allosteric modulators, few ECS pharmacophores for class A receptors have been identified. Using the turkey β(1)-adrenergic receptor crystal structure, we modeled the α(1B)-adrenoceptor (α(1B)-AR) to help identify the allosteric site for ρ-conopeptide TIA, an inverse agonist at this receptor. Combining mutational radioligand binding and inositol 1-phosphate signaling studies, together with molecular docking simulations using a refined NMR structure of ρ-TIA, we identified 14 residues on the ECS of the α(1B)-AR that influenced ρ-TIA binding. Double mutant cycle analysis and docking confirmed that ρ-TIA binding was dominated by a salt bridge and cation-π between Arg-4-ρ-TIA and Asp-327 and Phe-330, respectively, and a T-stacking-π interaction between Trp-3-ρ-TIA and Phe-330. Water-bridging hydrogen bonds between Asn-2-ρ-TIA and Val-197, Trp-3-ρ-TIA and Ser-318, and the positively charged N terminus and Glu-186, were also identified. These interactions reveal that peptide binding to the ECS on transmembrane helix 6 (TMH6) and TMH7 at the base of extracellular loop 3 (ECL3) is sufficient to allosterically inhibit agonist signaling at a GPCR. The ligand-accessible ECS residues identified provide the first view of an allosteric inhibitor pharmacophore for α(1)-adrenoceptors and mechanistic insight and a new set of structural constraints for the design of allosteric antagonists at related GPCRs.

Identification of Key Residues Essential for the Structural Fold and Receptor Selectivity within the A-chain of Human Gene-2 (H2) Relaxin

Human gene-2 (H2) relaxin is currently in Phase III clinical trials for the treatment of acute heart failure. It is a 53-amino acid insulin-like peptide comprising two chains and three disulfide bonds. It interacts with two of the relaxin family peptide (RXFP) receptors. Although its cognate receptor is RXFP1, it is also able to cross-react with RXFP2, the native receptor for a related peptide, insulin-like peptide 3. In order to understand the basis of this cross-reactivity, it is important to elucidate both binding and activation mechanisms of this peptide. The primary binding mechanism of this hormone has been extensively studied and well defined. H2 relaxin binds to the leucine-rich repeats of RXFP1 and RXFP2 using B-chain-specific residues. However, little is known about the secondary interaction that involves the A-chain of H2 relaxin and transmembrane exoloops of the receptors. We demonstrate here through extensive mutation of the A-chain that the secondary interaction between H2 relaxin and RXFP1 is not driven by any single amino acid, although residues Tyr-3, Leu-20, and Phe-23 appear to contribute. Interestingly, these same three residues are important drivers of the affinity and activity of H2 relaxin for RXFP2 with additional minor contributions from Lys-9, His-12, Lys-17, Arg-18, and Arg-22. Our results provide new insights into the mechanism of secondary activation interaction of RXFP1 and RXFP2 by H2 relaxin, leading to a potent and RXFP1-selective analog, H2:A(4-24)(F23A), which was tested in vitro and in vivo and found to significantly inhibit collagen deposition similar to native H2 relaxin.

Numerical prediction of the electrical waveform effect on electrocoalescence kinetic

The effect of external electric field characteristics on the binary water droplet coalescence in stagnant oil has been studied using Computational Fluid Dynamics (CFD) simulations. Volume of Fluid (VOF) approach is applied as a multiphase model, in which the hydrodynamic equations consisting of Navier–Stokes and interface tracking equations are solved using finite volume discretization scheme. Dipole-induced-dipole (DID) model is utilized to calculate the electrostatic force on water droplets. Different types of electrical waveforms have been implemented using appropriate potential functions. The studied electrical voltages are sine, triangle, sawtooth, pulsed DC, and bipolar square waveforms. The predicted kinetic for electrocoalescence is in good agreement with the experimental data of the literature. The results demonstrated that a bipolar square wave provided the most efficient waveform, while sine and pulsed DC voltages gave lower efficiencies due to the time variation and off-time intervals, respectively. Triangle and sawtooth waveforms produced the least efficient waveforms. In addition, the effect of frequency has been studied for the aforesaid electrical waveforms in the adopted binary drop system. No significant differences have been proved in the approaching time of the drops from the studied frequencies. The results revealed that the electric fields with higher value of root mean squares (RMS) result in more efficient electrocoalescences. Furthermore, it was manifested that the higher voltage amplitude in every waveform improves this phenomenon.

Effects of periodic and non‐periodic chaotic mixing on morphology development of immiscible polymer blends

AbstractThe effects of periodic and non‐periodic chaotic mixing on the morphology development in the blending of polypropylene as dispersed phase and polyamide 6 as continuous phase in a 2D batch chaotic mixer were investigated with experimental and computational fluid dynamic (CFD) methods. The rotor motions were delivered in steady, periodic (sine waveform and square waveform), and non‐periodic (recursive protocol (RP) and restricted random sequence (RRS)) manners. The mixing efficiency was evaluated with flow number, Poincare map, morphology, droplet size and its distribution. Compared with the sine waveform, RP waveform could eliminate the island structures which existed in the flow domains and its corresponding spatial stretching distribution was more uniform. The recursively generated flow using RP lead to higher mixing efficiency and smaller droplet size with narrow distribution. However, the performance of RRS was ordinary even worse due to its random sequence.© 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Relationships between Harmonic Characteristics and Different Types of Voltage Source

This paper discusses about harmonic characteristics due to different types of voltage sources. Ideal voltage source is sinusoid, unfortunately in actual condition load receives voltage sources from elements which produce the non sinusoidal output voltage, and consequently, the load has non pure sinusoid waveform as an input voltage. Voltage source at power of common coupling (PCC) between transformer and linear load and nonlinear load has become an example of the case. This research has been conducted by using Schhafner Power Quality Analyzer and PM300 Power Quality Analyzer, which was focused to figure out all characteristics related to harmonics such as power, voltage, current, power factor (p.f.), Harmonic Distortion, and harmonic energy losses cost. The selected load is induction motor with Adjustable Speed Drive (ASD) because this typical load is one of electronic device that causes harmonics. The voltage sources in this research are sine wave, square wave and harmonic order combinations of 3 rd , 5 th and 7 th which can create from Schhafner Power Quality Analyzer.

Low-frequency ac electroporation shows strong frequency dependence and yields comparable transfection results to dc electroporation

Conventional electroporation has been conducted by employing short direct current (dc) pulses for delivery of macromolecules such as DNA into cells. The use of alternating current (ac) field for electroporation has mostly been explored in the frequency range of 10kHz–1MHz. Based on Schwan equation, it was thought that with low ac frequencies (10Hz-10kHz), the transmembrane potential does not vary with the frequency. In this report, we utilized a flow-through electroporation technique that employed continuous 10Hz-10kHz ac field (based on either sine waves or square waves) for electroporation of cells with defined duration and intensity. Our results reveal that electropermeabilization becomes weaker with increased frequency in this range. In contrast, transfection efficiency with DNA reaches its maximum at medium frequencies (100–1000Hz) in the range. We postulate that the relationship between the transfection efficiency and the ac frequency is determined by combined effects from electrophoretic movement of DNA in the ac field, dependence of the DNA/membrane interaction on the ac frequency, and variation of transfection under different electropermeabilization intensities. The fact that ac electroporation in this frequency range yields high efficiency for transfection (up to ~71% for Chinese hamster ovary cells) and permeabilization suggests its potential for gene delivery.

Relationships between Harmonic Characteristics and Different Types of Voltage Source

This paper discusses about harmonic characteristics due to different types of voltage sources. Ideal voltage source is sinusoid, unfortunately in actual condition load receives voltage sources from elements which produce the non sinusoidal output voltage, and consequently, the load has non pure sinusoid waveform as an input voltage. Voltage source at power of common coupling (PCC) between transformer and linear load and nonlinear load has become an example of the case. This research has been conducted by using Schhafner Power Quality Analyzer and PM300 Power Quality Analyzer, which was focused to figure out all characteristics related to harmonics such as power, voltage, current, power factor (p.f.), Harmonic Distortion, and harmonic energy losses cost. The selected load is induction motor with Adjustable Speed Drive (ASD) because this typical load is one of electronic device that causes harmonics. The voltage sources in this research are sine wave, square wave and harmonic order combinations of 3 rd , 5 th and 7 th which can create from Schhafner Power Quality Analyzer.

Chaos Suppression in a Sine Square Map through Nonlinear Coupling

We study a pair of nonlinearly coupled identical chaotic sine square maps. More specifically, we investigate the chaos suppression associated with the variation of two parameters. Two-dimensional parameter-space regions where the chaotic dynamics of the individual chaotic sine square map is driven towards regular dynamics are delimited. Additionally, the dynamics of the coupled system is numerically characterized as the parameters are changed.

Self-Optimized Nonlinear PID Controller for Networked Chaotic Systems to Synchronize onto Arbitrary Orbit

Synchronization onto arbitrary orbit for diffusively coupled complex networks is of great application value and was investigated in this paper especially when nodes are chaotic systems. A decentralized nonlinear PID controller was proposed for this purpose. The controller was designed with assistance of associated feedback system of the network. A particle swarm style self-optimization algorithm was provided to find the optimal parameter of the controller online with IAE performance index. Finally a networked Chen system was given to be controlled to track sine wave, square wave and triangular wave simultaneously as the example to verify the method presented.

Accumulative deformation behaviour of loess under cyclic loading

A series of dynamic triaxial tests were carried out in this study, the accumulated plastic strain regulation of the saturated remoulded loess under cyclic loading was studied. Based on the test results, the exponential model applicability of the accumulated plastic strain of loess is discussed and another model of three parameters is proposed. The influences of the dynamic stress amplitude, dynamic loading frequency and wave type of cyclic loading on the accumulated plastic strain of loess are also discussed. With the increase in dynamic stress amplitude, the cycle number becomes less until reaching the same accumulated plastic strain. The accumulated plastic strain has no uniform regulation to the high or low frequency of dynamic loading. In three wave types of cyclic loading, the accumulated plastic strains caused by sine wave and square wave are minimum and maximum respectively. These conclusions can be referred for studying the accumulative behaviour of loess foundation.