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Purpose: In modern industry, titanium is recognised for its remarkable wear resistance and strength. However, its poor thermal conductivity poses a problem because it shortens the life cycle of cutting tools. Researchers have focused on enhancing the service life of cutting-edge tools, cutting production costs by using new coating materials, and identifying appropriate materials for these coatings. Design/methodology/approach: The experimental design involved tests with controlled cutting speeds of 150, 175, 200, and 225 m/min, feed rates of 0.2, 0.25, and 0.30 mm/rev, and cutting depths of 0.5, 1.0, and 1.2 mm. Titanium with a diameter of 25 mm and a length of 200 mm was prepared for the turning test over a machining distance of 20 mm. The chips obtained from the cutting test were observed and analysed using a scanning electron microscope to investigate the effect of the tool coating on the characteristics of the chip formation mechanism. Findings: The study revealed that inserts coated with AlCrSiTiN produced the characteristic of long twisted chips transitioning into continuous chips with shorter twisting distances than uncoated cermet inserts. The uncoated cermet inserts resulted in a greater twisting distance based on an examination of the chips with a scanning electron microscope, revealing more pronounced jaggedness in the fragments produced by the cermet turning inserts, which also possessed a larger average clearance than the inserts coated with AlCrSiTiN and TiAlSiN. Furthermore, the uncoated cermet inserts showed less wear at lower cutting speeds than the other types of inserts. Conversely, the TiAlSiN-coated inserts exhibited less wear at higher cutting speeds than the inserts of different materials. Research limitations/implications: The triangularly shaped inserts were cermet inserts coated with AlCrSiTiN or TiAlSiN via the PVD method and were used for dry turning. Practical implications: Wear of cutting-edge tools is a problem in turning of titanium. Therefore, it is crucial to identify methods to minimise wear and extend the service life considering the investment worthiness. Likewise, efforts are being made to develop new coatings tailored to the materials. Originality/value: The research could provide guidelines for reducing the wear generated in cutting tools and increasing the service life of cutting edges by adjusting the machining parameters. [ABSTRACT FROM AUTHOR]

An efficient light management technique is proposed and investigated by developing a TCAD model for microcrystalline silicon based thin film solar cell. The model includes physical insight related to some optical phenomenon like scattering and diffusive reflection of light as well as some electrical phenomena like carrier transport at the heterointerfaces. Two different structures, which comprises of sawtooth and grating-type back nanotextured in combination with random front nano-textured absorber layers are considered in this work. It has been observed that sawtooth or grating type back nano-textured absorber layer results in enhanced absorption of incident photons as compared to the planar back absorber layer. Also, the grating type back-textured absorber provides better performance compared to its sawtooth counterparts. Finally, the depth and period of grating are optimized in order to maximize the power conversion efficiency of grating-back-textured with random-front-textured absorber. The optimized structure results in an efficiency of 12.325% which corresponds to an improvement of 3.975% compared to the random front and back nano-textured thin film solar cell. [ABSTRACT FROM AUTHOR]

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To analyze the shear characteristics and mesoscopic failure mechanism of irregular serrated rock discontinuities, a great deal of interview samples of irregular serrated structures were made by 3D printing technology, and laboratory shear tests were carried out on them under different normal stresses. At the same time, PFC numerical simulation software is used to establish relevant models to study the evolution of microcracks and the distribution characteristics of the force chain on the rock discontinuity during the shear process. The results show that the shear mechanical properties of irregular serrated rock discontinuities are affected by normal stress, undulating angle, and undulating height. The shear strength increases with the increase of normal stress and undulating height, and decreases with the increase of undulating angle. The numerical simulation results show that the irregular structural surface cracks under different undulation angles, which first start at the near force end serration root on both sides and further evolve to the adjacent serrations, while the irregular structural surface cracks under different undulation heights, which first start at the serration root with the lowest height and expand to the adjacent serrations. At the same time, the number of cracks increases with the increase of normal stress and the force chain is mainly distributed near the sawtooth surface. The force chain is more concentrated near the near force end sawtooth and at the tip and root of the rest of the sawtooth. At the same time, the direction of the force chain is approximately perpendicular to the force surface of the sawtooth. The research results are helpful in further understanding the shear mechanical properties and differences of irregular serrated rock discontinuities. [ABSTRACT FROM AUTHOR]

This paper shows the performance and scalability evaluation of different blockchain platform implementations. Hyperledger Iroha implementing YAC consensus, Sawtooth implementing PoET algorithm, and Hyperledger Fabric framework implementation. Performance evaluation and scalability assessment were done by varying different sets of parameters such as block size, transaction sending rate, network traffic distribution, and network size. Performance evaluation was done based on average transaction latency, network throughput, and transaction failure rate. Scalability was assessed based on changes in transaction latency and throughput with increasing network size. Test results let to study the impact of a particular parameter on the private blockchain network performance and show how they can be adjusted to improve performance. [ABSTRACT FROM AUTHOR]

We theoretically explore the dynamics of a ferrofluid with temperature and magnetic field-dependent viscosity, which is in a Rayleigh–Bénard situation and is subjected to rotation. The problem considers both sinusoidal and non-sinusoidal time-periodic variations of rotation to study the onset and post-onset regimes of Rayleigh–Bénard ferroconvection. We perform a weakly nonlinear stability analysis using a truncated Fourier series representation and arrive at the third-order Lorenz system for ferrofluid convection with variable viscosity. By using the linearized form of the Lorenz system for ferrofluid convection with variable viscosity, we arrive at the critical Rayleigh number to study the onset of rotating ferroconvection. The heat transport is quantified in terms of the time-averaged Nusselt number and the effects of various parameters on it are studied. The effect of modulated rotation is found to have a stabilizing effect on the onset of ferroconvection while that of variable viscosity has a destabilizing effect. The effects of magnetorheological and thermorheological effects are antagonistic in nature. It is found that the square waveform modulation facilitates maximum heat transport in the system due to advanced onset of ferroconvection. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate a novel salinity sensor based on Tamm-plasmon-polariton (TPP), comprising different shapes of Bragg reflector (ordinary, texturing, and sawtooth) and metallic layer. The finite element method is used to study the considered structure and sensing performance by using the COMSOL multiphysics simulation procedure. Here, we study the effect of surface morphology on the sensitivity; firstly, in the case of one-dimensional photonic crystal-centered defect, it harms the sensitivity; secondly, texturing and sawtooth in the case of Tamm resonance increases the sensitivity, as for texturing the surface, the sensitivity quality factor (Q) = 236 and figure of merit (FOM) = 170. For sawtooth surfaces, Q = 272.4, and FOM = 199. The consequences of structural parameters on the efficiency of sensing are studied, and new procedures are proposed to enhance TPP-based sensors. A simple and functional alternative to conventional salinity sensors may be the proposed solution. [ABSTRACT FROM AUTHOR]

A simple, inexpensive and efficient circuit for generating sawtooth waves is demonstrated in this paper. The novelty of this work lies in the fact that the voltage of a charging capacitor provides linear response when it is charged through a reverse-biased diode. A rectangular wave of extremely high duty cycle is used as a reference signal to drive the passive circuit consists of a diode–capacitor pair. During the on-time of the reference signal, the diode remains in reverse biased condition while charging the capacitor and during charging through the reverse-biased diode, the capacitor voltage produces the required ramp. During the off-time of the reference wave, the diode becomes forward biased and the capacitor discharges very fast through the forward-biased diode and thus a sawtooth wave has resulted. At high frequencies, the parasitic depletion capacitance of the diode cannot be ignored and it limits the frequency of operation. Laboratory experiments, as well as PSPICE circuit simulations, are performed to established our idea of generating sawtooth waveforms. The experiment is found to be repetitive and robust. [ABSTRACT FROM AUTHOR]

Extensive research is carried out in the analysis of non stationary signals. Most of the real time signals are non-stationary in nature. In most cases, these non stationary signals are of types viz defect / non defect, normal / abnormal etc. Hence analysis refers to categorising the signals. Developing a signal processing algorithm for performing the above task is a major challenge. In Machine learning, features are extracted and classifiers are used for categorizing the signals. Feature extraction can be done in time domain, frequency domain and spectral domain. In this paper, feasibility of Singular Value Decomposition (SVD), Framelet Transforms, Discrete Wavelet Transform (DWT) and Discrete Cosine Transform (DCT) for feature extraction is studied. These features are aggregated using statistical parameters, namely mean, skewness and kurtosis. These aggregated features are then fed to Back Propagation Network (BPN). Performance of Back Propagation Network is measured in terms of sensitivity, specificity and accuracy. [ABSTRACT FROM AUTHOR]

The focal aim of this work was to build up an Elitist streamlined sawtooth genetic algorithm (SAWTGA) for anticipating the danger of coronary illness to a patient with the clinical records got from the patients. The classification was performed by machine learning technique to foresee the danger of heart disease. Thirteen features were given as input to the classifier. The proposed system can be utilised by the specialists to anticipate the illness in the previous stages proficiently with improved accuracy. The viability of the methodology has been assessed with the tuples accessible in the informational index. The results exhibited that the proposed calculation outperforms existing method. SAWTGA classifier can anticipate the likelihood of patients with coronary sickness in a more promising manner. The exploratory outcomes have demonstrated that the proposed approach has accomplished improvement in accuracy. This actualises that the elitist streamlined Sawtooth Genetic Algorithm will be a sought-after classifier that could be helpful guide for the specialists to productively and precisely anticipate the coronary illness with improved accuracy. [ABSTRACT FROM AUTHOR]

The paper sheds light on the linear and nonlinear stability of a ferrofluid with the temperature and magnetic-field-dependent viscosity subjected to an imposed time-periodic gravity modulation. The perturbations in the system due to external reasons are expanded in terms of the amplitude of modulation in the case of linear stability and a truncated representation of the Fourier series in the case of nonlinear stability. A nonautonomous Lorenz model for the problem is first obtained, and both linear and nonlinear analyses of the system are performed using this. The expression for the critical Rayleigh number, R0, and the correction Rayleigh number, R2c, is found from the linearized Lorenz model. The Lorenz system of equations is solved for the amplitude to arrive at the Nusselt number (Nu), which quantifies the heat transport. In the study we find that the thermorheological effect and the magnetization effect work in unison to destabilize the system, while the magnetorheological effect and the effect of vertical oscillations stabilize the system. The influence of the parameters on the heat transport is the opposite to their effect on the critical Rayleigh number. The results of the paper agree quite well with those of limiting cases. [ABSTRACT FROM AUTHOR]

Self‐motion perception is a key aspect of higher vestibular processing, suggested to rely upon hemispheric lateralization and alpha‐band oscillations. The first aim of this study was to test for any lateralization in the EEG alpha band during the illusory sense of self‐movement (vection) induced by large optic flow stimuli. Visual stimuli flickered at alpha frequency (approx. 10 Hz) in order to produce steady state visually evoked potentials (SSVEPs), a robust EEG measure which allows probing the frequency‐specific response of the cortex. The first main result was that differential lateralization of the alpha SSVEP response was found during vection compared with a matched random motion control condition, supporting the idea of lateralization of visual–vestibular function. Additionally, this effect was frequency‐specific, not evident with lower frequency SSVEPs. The second aim of this study was to test for a causal role of the right hemisphere in producing this lateralization effect and to explore the possibility of selectively modulating the SSVEP response. Transcranial alternating current stimulation (tACS) was applied over the right hemisphere simultaneously with SSVEP recording, using a novel artefact removal strategy for combined tACS‐EEG. The second main result was that tACS enhanced SSVEP amplitudes, and the effect of tACS was not confined to the right hemisphere. Subsequent control experiments showed the effect of tACS requires the flicker frequency and tACS frequency to be closely matched and tACS to be of sufficient intensity. Combined tACS‐SSVEPs are a promising method for future investigation into the role of neural oscillations and for optimizing tACS. [ABSTRACT FROM AUTHOR]

The sawtooth oscillation involves a topological change of the magnetic field lines in the core of a tokamak discharge. We simulate a steady state sawtoothing discharge using the M3DC¹-code. During the sawtooth the topological structure of the magnetic field is analyzed by tracking the fixed points of the field line map: the mapping induced by the field lines going once around the tokamak. We numerically locate the fixed points of the field line map (of which the magnetic axis is one) and use them construct a Poincaré section that resolves the core region and the (1, 1) island. By following the evolution of the magnetic field through the motion and bifurcation of the fixed points of the field line map we get an intuitive picture of the processes that take place during a Kadomtsev style sawtooth crash. [ABSTRACT FROM AUTHOR]

A special structure with Al-composition graded barriers in the active region was designed to provide a sawtooth layer for the multiple quantum barriers, which were investigated numerically. The simulation demonstrates that the output power of optimized structure has reached to 50 mW and the efficiency droop also has significantly improved. By detailedly analyzing the results, the advantages of the ultraviolet light emitting diodes with sawtooth barriers are attributed to the design, which could enhance the ability of electrons reservoir, modulate carrier distribution and suppress electron spill out from the active region. As a result, it can enhance the rate of carrier radiation recombination and ameliorate internal quantum efficiency. [ABSTRACT FROM AUTHOR]

Purpose. Myopia (short-sightedness) is the commonest visual disorder and greatest risk factor for sight threatening secondary pathologies. Myopia and hyperopia can be induced in animal models by rearing with optical lens defocus of opposite sign. The degree of refractive compensation to lens-induced defocus in chicks has been shown to be modified by directionally drifting sawtooth spatio-temporal luminance diamond plaids, with Fast-ON sawtooth spatio-temporal luminance profiles inhibiting the myopic shift in response to negative lenses, and Fast-OFF profiles inhibiting the hyperopic shift in response to positive lenses. What is unknown is whether similar signof-defocus dependent results produced by spatio-temporal modulation of sawtooth patterns could be achieved by rearing chicks under whole field low temporal frequency sawtooth luminance profiles at 1 or 4 Hz without a spatial component, or whether such stimuli would indiscriminately elicit a myopic shift such as that previously shown with symmetrical (or near-symmetrical) low frequency flicker across a range of species. Methods. Hatchling chicks (n D 166) were reared from days five to nine under one of three defocus conditions (No Lens, C10D lens, or -10D lens) and five light conditions (No Flicker, 1 Hz Fast-ON/Slow-OFF sawtooth flicker, 4 Hz Fast-ON/Slow-OFF sawtooth flicker, 1 Hz Fast-OFF/Slow-ON sawtooth flicker, or 4Hz Fast-OFF/Slow-ON sawtooth flicker). The sawtooth flicker was produced by light emitting diodes (white LEDs, 1.2 -183 Lux), and had no measurable dark phase. Biometrics (refraction and ocular axial dimensions) were measured on day nine. Results. Both 1 Hz and 4 Hz Fast-ON and Fast-OFF sawtooth flicker induced an increase in vitreous chamber depth that was greater in the presence of negative compared to positive lens defocus. Both sawtooth profiles at both temporal frequencies inhibited the hyperopic shift in response to C10D lenses, whilst full myopic compensation (or over-compensation) in response to -10D lenses was observed. Conclusions. Whole field low temporal frequency Fast-ON and Fast-OFF sawtooth flicker induces a generalized myopic shift, similar to that previously shown for symmetrical sine-wave and square-wave flicker. Our findings highlight that temporal modulation of retinal ON/OFF pathways per se (without a spatial component) is insufficient to produce strong sign-of-defocus dependent effect. [ABSTRACT FROM AUTHOR]

This study focuses on the influence of the sawtooth side edges on the cutting force and analyzes the functions of the side edges in wood sawing by separating the total cutting force into the force from the main edge and the side edges. Birch (Betula spp.) is used as the material for conducting the experiment. The influence of the sawtooth side edges with different radial clearance angles on the cutting force was studied by comparing closed cutting with open cutting for different cutting thicknesses, cutting speeds, and directions using a single sawtooth. The cutting force from the side edges accounts for 4.6 % to 16.9 % of the total cutting force when the sawing kerf is 1.6 mm. As the radial clearance angle increases or the cutting thickness decreases, the cutting force from the side edges and the proportion of the force from the side edges decrease. The cutting force from the side edges increases with an increase in the cutting speed but the cutting speed does not have a clear influence on the cutting force from the side edges. For the same radial clearance angle, the cutting force from the side edges is the largest for the (0°–90°), followed by the (90°–0°) and the (90°–90°). [ABSTRACT FROM AUTHOR]

Context Improving surface roughness of wood in rip sawing by optimizing the sawtooth parameters is a significant topic of focus in the research of wood processing. However, existing research focuses mainly on the optimization of the sawtooth parameters of the major cutting edges without taking into account the influences of length and angle of the side edges on surface roughness. Thus, adaptive parameters for the side edges should be proposed. Aims This study analyzes how the different parameters of side edges influence surface roughness when circular saws are used, and aims to resolve disparities between high feed speeds and better surface roughness. Methods In particular, this article presents the use of a sawtooth with a mic-zero-degree radial clearance angle. Northeast China ash (Fraxinus spp.) serves as the material for conducting this rip-sawing experiment. Nine types of sawtooth geometries at different feed speeds are used to study the influences of both the different radial clearance angles and the straight length of the zero-degree radial clearance angle on surface roughness (Ra). Results Surface roughness increases with the increase in feed speed, and the smaller the radial clearance angle of the sawteeth, the smaller the surface roughness. When the sawteeth have a mic-zero-degree radial clearance angle, the sawing surface roughness is lower than that of the value of sawteeth with radial clearance angles, especially when the straight length of the zero-degree radial clearance increases from 0 to 0.5 mm, in which case the decrease is most obvious. Conclusion Surface roughness depends, to a certain extent, on the depth of the saw notch. A small part of the side edge that forms the sawing surface participates in the actual cutting, and the length of this section is approximately equal to the feed per tooth. Sawteeth with mic-zero-degree radial clearance angles can improve the surface quality of sawing. Also, if the other cutting factors remain unchanged, surface roughness can be improved and friction can be reduced between the side edges and the wood by increasing the feed speed. [ABSTRACT FROM AUTHOR]

People can speak, and this provides opportunities to analyze human emotions using perceived experiences communicated via language, as well as through measurement and imaging techniques that are also applicable to other higher animal species. Here I compare four qualitative methodological approaches to test if, and how, thrill depends on fear. I use eight high-risk, high-skill, real-life outdoor adventure recreation activities to provide the test circumstances. I present data from: >4000 person-days of participant observation; interviews with 40 expert practitioners; retrospective autoethnography of 50 critical incidents over 4 decades; and experimental autoethnography of 60 events. Results from different methods are congruent, but different approaches yield different insights. The principal findings are as follows. Individuals differ in their fear and thrill responses. The same individual may have different responses on different occasions. Fear boosts performance, but panic causes paralysis. Anxiety or apprehension prior to a risky action or event differs from fear experienced during the event itself. The intensity of pre-event fear generally increases with the immediacy of risk to life, and time to contemplate that risk. Fear must be faced, assessed and overcome in order to act. Thrill can occur either during or after a high-risk event. Thrill can occur without fear, and fear without thrill. Below a lower threshold of perceived risk, thrill can occur without fear. Between a lower and upper threshold, thrill increases with fear. Beyond the upper threshold, thrill vanishes but fear remains. This there is a sawtooth relation between fear and thrill. Perceived danger generates intense focus and awareness. Fear and other emotions can disappear during intense concentration and focus. Under high risk, the usual emotional sequence is fear before the action or event, then focus during the action or event, then thrill, relief, or triumph afterward. The emotionless state persists only during the most intense concentration. For events long enough to differentiate time within the events, fear and thrill can arise and fade in different fine-scale sequences. [ABSTRACT FROM AUTHOR]

Electroretinogram (ERG) studies have demonstrated that the retinal response to temporally modulated fast-ON and fast-OFF sawtooth flicker is asymmetric. The response to spatiotemporal sawtooth stimuli has not yet been investigated. Perceptually, such drifting gratings or diamond plaids shaded in a sawtooth pattern appear brighter when movement produces fast-OFF relative to fast-ON luminance profiles. The neural origins of this illusion remain unclear (although a retinal basis has been suggested). Thus we presented toad eyecups with sequential epochs of sawtooth, sine-wave, and square-wave gratings drifting horizontally across the retina at temporal frequencies of 2.5-20 Hz. All ERGs revealed a sustained direct-current (DC) transtissue potential during drift and a peak at drift offset. The amplitudes of both phenomena increased with temporal frequency. Consistent with the human perceptual experience of sawtooth gratings, the sustained DC potential effect was greater for fast-OFF cf. fast-ON sawtooth. Modeling suggested that the dependence of temporal luminance contrast on stimulus device frame rate contributed to the temporal frequency effects but could not explain the divergence in response amplitudes for the two sawtooth profiles. The difference between fast-ON and fast-OFF sawtooth profiles also remained following pharmacological suppression of postreceptoral activity with tetrodotoxin (TTX), 2-amino-4-phosphonobutric acid (APB), and 2,3 cis-piperidine dicarboxylic acid (PDA). Our results indicate that the DC potential difference originates from asymmetries in the photoreceptoral response to fast-ON and fast-OFF sawtooth profiles, thus pointing to an outer retinal origin for the motion-induced drifting sawtooth brightness illusion. [ABSTRACT FROM AUTHOR]

Transcranial alternating current stimulation (tACS) has until now mostly been administered as an alternating sinusoidal wave. Despite modern tACS stimulators being able to deliver alternating current with any arbitrary shape there has been no systematic exploration into the relative benefits of different waveforms. As tACS is a relatively new technique there is a huge parameter space of unexplored possibilities which may prove superior or complimentary to the traditional sinusoidal waveform. Here, we begin to address this with an investigation into the effects of sawtooth wave tACS on individual alpha power. Evidence from animal models suggests that the gradient and direction of an electric current should be important factors for the subsequent neural firing rate; we compared positive and negative ramp sawtooth waves to test this. An additional advantage of sawtooth waves is that the resulting artifact in the electroencephalogram (EEG) recording is significantly simpler to remove than a sine wave; accordingly we were able to observe alpha oscillations both during and after stimulation. We found that positive ramp sawtooth, but not negative ramp sawtooth, significantly enhanced alpha power during stimulation relative to sham (p < 0.01). In addition we tested for an after-effect of both sawtooth and sinusoidal stimulation on alpha power but in this case did not find any significant effect. This preliminary study paves the way for further investigations into the effect of the gradient and direction of the current in tACS which could significantly improve the usefulness of this technique. [ABSTRACT FROM AUTHOR]

Compared with powder-based process of additive manufacturing, slurry-based process can fabricate the ceramic components with better green density by casting thinner layers to improve the step effect. The main objective of this study is to develop a reliable slurry-layer casting system for building ceramic green parts. A premetered slurry-feeding mechanism was built to steadily supply the slurry and prevented the ripples on the layer from pulsation. Based on the techniques of slot-die coating and tape casting, a novel coater including a coat hanger distribution chamber and a doctor blade was designed and built to observe the distribution of the specified slurry and verify the feasibility of the slurry-layer casting. The experiment results revealed the distribution chamber with a suitable coat hanger angle that can uniformly deliver the slurry to the lips of the coater. The premetered coating method can simplify the process variables involved in the casting process. The slurry feeder exerts a considerable force on the slurry to overcome the influence of the viscosity. Sawtooth effect in the slurry-layer casting was observed and eliminated through the process of slurry preloading. Furthermore, an online coater cleanup device, which possesses the features of simple structure and high efficiency of residual slurry removal, was proposed. For the slurry with different formation used in the additive manufacturing of ceramic products, this study can be a pattern to build a reliable slurry-layer casting system with the principle of simple design, low cost, and easy cleanup. [ABSTRACT FROM AUTHOR]

Purpose: The d-wave is typically elicited after the termination of an increment flash, but a decrement flash provides an alternative, and perhaps more appropriate, stimulus to elicit the d-wave. Here, we investigated the affects of stimulus polarity on the electroretinogram (ERG) response. Methods: ERG responses elicited to increment and decrement flashes of varying intensity and duration from different background levels were measured from human participants to assess the b-wave and d-wave responses as a function of adaptation level and flash polarity. Response amplitudes were measured using standard metrics for waveform analysis. Results: The amplitude of the b-wave is larger than the d-wave regardless of flash polarity when using different background levels which maximized the dynamic range of the two waveforms. However, when response amplitudes are measured from a common background, the d-wave elicited with decrement flash was larger than the b-wave elicited by an increment flash. This trend was evident across a range of background levels. The b-wave and d-wave become separate entities when flash duration reaches approximately 50 ms. Rapid-on and rapid-off sawtooth stimuli were also tested against increment and decrement step stimuli that were matched in mean luminance. These two stimulus types produced different amplitude b-wave and d-wave responses, suggesting asymmetric effects of the two stimulus types on the retinal response. Conclusions: We conclude that the response properties of the b-wave and d-wave are influenced by the duration, polarity and waveform of the stimulus, as well as the background from which the stimuli arise. [ABSTRACT FROM AUTHOR]

This study presents an investigation on both the processing and morphological aspects of cutting-based metal fibers. A self-designed multi-tooth cutter is used to efficiently make continuous long fibers under a low-speed dry-cutting condition. A finite element method-aided analysis is conducted to elucidate the mechanisms of this method. Based on both simulated and experimental results, it is found that fiber morphology shows different characteristics when different processing parameters are used. Moreover, the fiber structure and appearance also significantly depends on the mechanical properties of raw materials. It is shown that the Cu fiber belongs to flow chip due to highly plastic deformation, while the hardened Cu-Be, Cu-Be-Ni alloy and SUS316L fibers exhibit fractured features. The combined segmented vertical fins and sawtooth structures can be periodically formed on the Cu-Be fibers under an appropriate condition. Besides these findings, the effects of sintering condition on the fiber morphology are also reported in this work. [ABSTRACT FROM AUTHOR]

Sawtooth patterns in the I\--V curves of superlattices result from the bistability induced by the negative differential resistance of the local J-F curve. This behavior has been extensively studied in weakly coupled superlattices from a transport point of view. In this paper, we show that the sawtooth patterns not only affect the dark current but also the noise and responsivity properties of a quantum well infrared photodetector. Their impact on the imaging properties of the detector is also quantified. [ABSTRACT FROM PUBLISHER]

Electrical stimuli pace, cardiovert, or defibrillate the heart by changing transmembrane potential (ΔVm). Recent simulation studies provide insights Into mechanisms by which stimuli establish ΔVm. This review attempts a nonmathematical description of these mechanisms. We start with the cable model in which the intracellular core conductor is bounded by a highly resistive and capacitive membrane that separates the intracellular and extracellular spaces. Intracellular and extracellular resistances are assumed to vary linearly with position. Although this model predicts anodal extracellular stimuli hyperpolarize adjacent tissue and cathodal extracellular stimuli depolarize that tissue, it fails to reproduce regions of opposite ΔVm distant from the electrodes, We then consider the sawtooth model in which microscopic discontinuities in intracellular resistance represent gap junctions. While model studies with such discontinuities demonstrate large ΔVm at cell ends, experimental validation of such ΔVm remains elusive. Extending the analysis to the two- and three-dimensional syncytium, we also consider the bidomain model in which intracellular, extracellular, and interstitial currents are explicitly characterized. Differences in resistance to these currents gives rise to virtual electrodes, which are experimentally observed regions of large ΔVm that arise distant from the stimulating electrode. Distant ΔVm regions are also evident when macroscopic discontinuities in intracellular resistance are introduced into the bidomain model. Such discontinuities are associated with clefts or scars that give rise to "secondary sources." Albeit the cable model offers remarkable insight the bidomain model and the concept of secondary sources provide a more complete understanding of membrane excitation, especially when combined into a unifying activating function. [ABSTRACT FROM AUTHOR]

The structures of three operating regions in HT-6B Tokamak have been studied by soft X-ray tomographic system with high sensibility and high time-space resolution. One of the requisites for forming sawtooth discharge is the effective heating action in the central region. In the sawtooth region there are five evolutional phases and five types of magnetic surface structures correspondingly; that is, the concentric, the eccentric, the double-core, the “MHD-type” and the “ultra-MHD type” magnetic surface structures. In the MHD oscillation region, there is a stable “MHD-type” magnetic surface structure. It consists of a crescent “hot core” and a circular “cold bubble” and rotates in the diamagnetic direction of electrons. In the resonant region, the resonant helical field improves the heating status and suppresses the MHD disturbances; therefore the single “MHD-type” magnetic surface changes into a sawtooth type one. [ABSTRACT FROM AUTHOR]