False Turn Research Articles

(Invited, Digital Presentation) Clarification of Possible Factors to Determine Flat-Band Voltage in 4H-SiC Gate Stacks with Nitrogen Passivation Processes

Control of flat-band voltage (Vfb) in 4H-SiC gate stacks is inevitable for high-voltage power MOSFET applications, since a sufficiently large threshold voltage (Vth) is required to suppress the false turn on. However, the increase in channel doping concentration to tune Vth results in a drastic reduction of carrier mobility in the inversion channel, due to Coulomb scattering caused by SiO2/4H-SiC interface [1]. Therefore a negative shift of Vfb is not preferred in terms of channel resistance reduction. The SiC surface nitridation process by a post-oxidation annealing (POA) in NO ambient at elevated temperature is an inevitable technique to suppress the interface defects [2]. However, a serious drawback is the fact that a negative shift of Vfb is often observed by employing NO-POA.Two possible mechanisms are to be considered which cause negative Vfb shifts in SiO2/4H-SiC MOS gate stacks: the generation of positive fixed charges, and the formation of interface dipole layers. We systematically investigated the flat-band voltage of SiO2/4H-SiC (0001) n-type MOS capacitors with various oxide thickness, fabricated by conventional dry oxidation followed by NO-POA at 1150℃ for several hours. When fixed charges are existing at the interface, it is natural to observe a linear relationship between the oxide thickness and Vfb, where we can estimate the fixed charge density from the slope. As a result, we found that the fixed charge densities were quite small after sufficient nitridation processes, however, an anomalous negative shift of Vfb in several hundreds of mV irrespective of oxide thickness was observed, which was enlarged by extending NO annealing duration [3]. This anomalous shift would be explainable by assuming a dipole layer formation at the interface by SiC surface nitridation, which may be caused by polar Si3-N tetrapod structure formation with high density aligned at the interface.Next we studied the impact of additional annealing after nitridation on Vfb, since the SiC device processes in general require such additional annealing including metallization processes. We conducted an additional 1 min rapid thermal annealing in N2 after NO-POA (post-nitridation anneal; PNA) at various temperatures from 800 to 1150℃. As a result, positive interface fixed charges were generated more by the PNA at higher temperatures [4], while fixed charge generation was insignificant by the PNA at low temperature such as 800℃ [4]. Note that interface state density did not change significantly by these PNA processes.Besides the influences on the Vfb shift, the interface dipole layer formation naturally affects the SiO2/4H-SiC band alignment. The conduction band offset, which is one of the critical factors to determine the gate leakage current level, must be dependent on the dipole layer strength. The valence-band spectra analysis using x-ray photoelectron spectroscopy and the energy barrier height characterization of Fowler-Nordheim current analysis tell us that the conduction-band offset at SiO2/SiC interface monotonically becomes larger by increasing the amount of nitrogen at the interface, which is consistent with the negative shift of Vfb observed in MOS capacitors [3]. To our surprise, this trend appeared in opposite direction when the gate stacks were fabricated on 4H-SiC (1-100) wafers [5].Finally we examined another way to tune the Vfb of SiC gate stacks by the introduction of additional dipole layer, by depositing of just a few nm-thick Al2O3 layer on top of SiO2 after NO-POA, based on the concept of oxide interface dipole layers reported for various high-k/SiO2 interfaces. As a result we successfully demonstrated ~1V Vfb shift without any deterioration of interface state density only by Al2O3 deposition [6]. This technique is expected as an additional method to achieve larger Vfb.In conclusion, we found that Vfb of nitrogen passivated SiO2/4H-SiC gate stacks is significantly affected by two factors: the positive fixed charges at the interface mainly introduced by post-nitridation annealing, and the interface dipole layer formation due to the polar structures aligned at the interface, or the intentionally introduced dipole layer by depositing a few nm-thick Al2O3 on top of SiO2.[1] M. Noguchi et al., Jpn. J. Appl. Phys. 58, 031004 (2019).[2] J. Rozen et al., J. Appl. Phys. 105, 124506 (2009).[3] T. H. Kil and K. Kita, Appl. Phys. Lett. 116, 122103 (2020).[4] T. H. Kil and K. Kita, 2021 International Workshop on Dielectric Thin Films for Future Electron Devices: Science and Technology (IWDTF), Nov. 2021.[5] T. H. Kil, A. Tamura, S. Shimizu and K. Kita, Appl. Phys. Express 14, 081005 (2021).[6] T. H. Kil, M. Noguchi, H. Watanabe, and K. Kita, Solid-State Electronics 183, 108115 (2021).

Paul M. van Buren's A Theology of the Jewish-Christian Reality

Paul M. van Buren was the first Christian theologian to argue that the Jewish No to Jesus is a Yes to God. He offered Christians and Jews fresh ways of understanding both themselves and the other. His trilogy, A Theology of the Jewish-Christian Reality, begins by honoring God's enduring covenant with the Jews and then proceeds to identify false turns both traditions have taken in their walks with God. He called both to critical self-reflection in theological conversation with the other's identity and missteps. He turned the church from being against the Jews to being alongside them and called Jews to return to God's covenant with them in order that Christian rethinking not be theologically empty.

Principle of Organization for Laboratory Stand of the Electric Drive with a Real Regulatory System No Time Scaling

The existing practical training of specialists in the field of the electric drive is recognized as insufficient, not allowing them to conduct independently a complex of adjustment works or works on elimination of refusals. All known virtual methods of research of electric drives are scaled in time therefore at the trained skills on use of the measuring and registering devices during the work on real installation don't develop, and also skills on work with real knots of control systems for control of the set drive modes. We propose a stand consisting of a real system of regulation and the model of the power drive to work without time scale, thus significantly closer to the actual laboratory setting drive. The structure of the laboratory stand on the basis of the engine of a direct current of independent excitement with the reversible thyristor converter is in details considered. It is proved that an optimal algorithm for the simulation of three-phase bridge converter operating at anchor chain is an algorithm which rooms include a thyristor and of the remaining thyristors allows you to choose the design scheme and carry out the integration of equations describing electric processes in the circuit detect a change in state of the thyristors and the transition to other design scheme. Given the discrete model and considered design scheme of three-phase bridge Converter in a normal mode switching thyristors and emergency mode, if false turn on of the thyristor during commutation. Mathematical model of the device - the solution of differential equations by numerical integration of the Runge-Kutta. Proposed hardware mathematical model based on the family of microcomputer ARM СortexTM fourth generation.

Quantitative Model-Based False Turn-on Evaluation and Suppression for Cascode GaN Devices in Half-Bridge Applications

Owing to the high operation frequency and fast switching speed, gallium nitride (GaN) devices are prone to the false turn- on phenomenon, causing high switching loss, shoot through, and even sustained oscillation. However, most of research on false turn- on aims at the enhancement-mode GaN devices, whereas there is still little published research on GaN devices in cascode configuration due to the comparatively complicated structure and various parasitic components. This paper conducts a comprehensive and in-depth study for the problem of false turn- on in cascode GaN devices based half-bridge circuits, which has a great guiding significance in the device selection, printed circuit board (PCB) design, and debugging of cascode GaN converters. In this paper, a novel analytical model of the device suffering false turn- on is first developed, with all the parasitic parameters being fully considered. Based on the model, the quantitative and accurate expression of the induced gate-to-source voltage is derived, which can serve as a precise and significant reference for judging and evaluating the false turn- on problems. Then, the influences of device and circuit parameters on the peak value of induced voltage are first investigated in detail, providing a reliable guidance for the usage and PCB design of cascode GaN devices based half-bridge converters. What's more, guidelines to effectively suppress the false turn- on phenomenon are also given, which can be adopted both in the design and debugging process of cascode GaN applications. Finally, all the theoretical calculations and analysis are verified by experiments with satisfying results and performances.

A New Analytical Model for Predicting $dv/ dt$-Induced Low-Side MOSFET False Turn-ON in Synchronous Buck Converters

This paper presents new studies of $dv/ dt$ -induced low-side mosfet false trigger when the high-side mosfet is turned on in synchronous buck converters. New analytical expressions are derived and utilized to predict both the magnitude and duration of the false triggering pulse to reveal more physical insight into the phenomenon. In contrast to the existing simple analytical model, the new model takes into account effects of nonlinear time-varying nature of the low-side mosfet drain-to-source capacitance $dv/ dt$ , the low-side mosfet body-diode reverse-recovery current and common-source inductance during the entire high-side mosfet turn- on transition. On the other hand, unlike the high-order complex model, which can only be solved numerically, the proposed analytical model is expressed explicitly by a set of parasitic parameters, and consequently their effects on the low-side mosfet false trigger can be explored much more easily. The model is mostly suitable for low-voltage applications in which false turn- on of the low-side mosfet could happen more often than under high-voltage conditions due to lower mosfet gate threshold voltage and higher $dv/ dt$ . The model is tested on an experimental 12–1.35 V, 8 A synchronous buck converter, and predictions are compared with experimental data with favorable correlation.

"A Bit of Ashes in Their Hands": The Dysphoria of Success in Sister Carrie

"A Bit of Ashes in Their Hands"The Dysphoria of Success in Sister Carrie J. Bret Maney (bio) And now Carrie had attained that which in the beginning seemed life's object, or, at least, such fraction of it as human beings ever attain of their original desires. She could look about on her gowns and carriage, her furniture and bank account. Friends there were, as the world takes it—those who would bow and smile in acknowledgment of her success. For these she had once craved. Applause there was, and publicity—once far off, essential things, but now grown trivial and indifferent. —Carrie "singing and dreaming" in her rocking chair at the end of Sister Carrie (367–68) When Theodore Dreiser visited Paris in 1926, a dutiful profile of him appeared in the French press. Among general remarks about Dreiser's novels, then little known in France, the critic Victor Llona, the future translator of An American Tragedy, paused to observe that Dreiser's characters "realize that success leaves nothing but a bit of ashes in their hands" (Dreiser, Interviews 130). Llona's figure of speech, which derives from the mythical apple of Sodom—a tree whose fruits, when plucked, supposedly turned into smoke and ash—draws our attention to the slight yield of pleasure that success affords in the Dreiser corpus. While Llona had The Titan (1914) and The "Genius" (1915) in mind, in particular, we may apply his remark with equal, if not greater weight, to Sister Carrie (1900), Dreiser's first novel about a young woman who flees the countryside to seek fame and fortune in the city, yet whose eventual success as a theatrical star is crowned by unhappiness. By foregrounding the marked dysphoria of success in Sister Carrie, this essay helps reframe debates about Dreiser's ambivalent representation of the rewards of capitalist striving and seeks to [End Page 1] place his critique of success in light of current interdisciplinary work in the fields of happiness studies and economics.1 An author whose surname is a near anagram for "desire," Dreiser remains justly famous for his evocation of capitalist desire's power. Indelible scenes of consumer lust like Carrie's acquisitive eyeballing of commodities in The Fair department store have been amply studied by Rachel Bowlby and other critics. Yet the frequent marring of the fruits of capitalist success by unhappiness in Dreiser's writing makes these same market-oriented desires appear distorted and casts doubt on the promise, implicit in consumer capitalism, of mapping the human yearning for happiness onto a quest for goods. Can the fruits of a budding turn-of-the-century consumer culture lead to emotional fulfillment, as Carrie thinks they will when she strolls through the aisles of the department store based on the real-life Marshall Fields, or do they always turn to ashes, as with the apple of Sodom, once the consumer has them in her grasp? Can economic ascent offer a path to self-realization? If not, what is the point of toil in an increasingly affluent American society? These are questions Dreiser may have been asking himself in Paris, in 1926, when he was at the height of his own material success as an author.2 But they are not necessarily questions with which we would frame a conversation about the affective dimensions of success in Sister Carrie. When Carrie's unhappy success is discussed in the critical literature, it is usually cited as evidence to support critics' positions within the larger debate whether Dreiser's first novel is, in Alan Trachtenberg's words, "for or against capitalism" ("Who Narrates" 87). Critics who see Sister Carrie as critical of capitalism argue that the novel devalues Carrie's success. For them, Carrie's rise to affluence and stardom in the commercial theater is a false turn that Carrie must disavow in order to achieve true satisfaction as a serious artist. Ellen Moers, for example, writes forcefully of Dreiser's critique in the novel of "metropolitan success," linking Carrie's misguided pursuit of fame, glittering consumer goods, and money to Dreiser's censorious view of his brother Paul's Broadway success (37, 103). In similar fashion, Richard...

Predicting SiC MOSFET Behavior Under Hard-Switching, Soft-Switching, and False Turn-On Conditions

Circuit-level analytical models for hard-switching, soft-switching, and $dv/ dt$ -induced false turn on of SiC MOSFETs and their experimental validation are described. The models include the high-frequency parasitic components in the circuit and enable fast, accurate simulation of the switching behavior using only datasheet parameters. To increase the accuracy of models, nonlinearities in the junction capacitances of the devices are incorporated by fitting their nonlinear curves to a simple equation. The numerical solutions of the analytical models provide more accurate prediction than an LTspice simulation with a threefold reduction in the simulation time. The analytical models are evaluated at 25 °C and 125 °C. The effect of snubber capacitors on the soft-switching waveforms is explained analytically and validated experimentally, which enables the techniques to be used to evaluate future soft-switching solutions. Finally, the $dv/ dt$ -induced false turn-on conditions are predicted analytically and validated experimentally. It was observed that consideration of nonlinearities in the junction capacitances ensures accurate prediction of false turn on, and that the small shoot-through current due to false turn on can increase the switching loss by 8% for an off-state gate bias of −2 V.

Reading Romans with St. Thomas Aquinas ed. by Matthew Levering, Michael Dauphinais

650 BOOK REVIEWS Reading Romans with St. Thomas Aquinas. Edited by MATTHEW LEVERING and MICHAEL DAUPHINAIS. Washington, D.C.: The Catholic University of America Press, 2012. Pp. 336. $55.00 (cloth). ISBN: 978-0-81321962 -2. This volume comprises a collection of sixteen essays on diverse topics concerning Aquinas’s commentary on Paul’s Letter to the Romans. With ten Catholic and seven Protestant scholars contributing to the book (one article is co-authored), it can be counted an ecumenical effort. In chapter 1, “Aquinas on Paul’s Flesh/Spirit Anthropology in Romans,” Bernhard Blankenhorn first dismisses the notion that Paul’s anthropology offers a simplistic dualism, explaining how according to Paul’s usage, pneuma “does not refer to the individual soul or a spiritual substance” and sarx often refers “to something other than an individual body” (2). Next, Blankenhorn reviews the major lines of Augustine’s interpretation of Paul’s flesh/spirit anthropology, noting the evolution of his exegesis, from which investigation he will be able to determine that Aquinas is strongly influenced for better and for worse by Augustine’s reading (37). Finally, focusing on Aquinas’s commentary on Romans and the Summa Theologiae but also briefly comparing the commentary on Galatians, Blankenhorn concludes that Aquinas’s treatment of Paul’s flesh/spirit anthropology accords with more general characteristics of his exegesis of Paul: that is, although Aquinas does not take note of the literary genre Paul employs, he grasps the essence of Paul’s intended teaching. Blankenhorn faults the Angelic Doctor for not interpreting Paul in his own historical context, concluding that at certain points in his works he misreads (15), misinterprets (16, 25, 37), and is not able to understand Paul (23), but is led astray (24), makes exegetical mistakes (32), takes false turns (38), and in one lectio offers a terribly unsatisfying exegesis (26); yet Blankenhorn recognizes as well that “the theologian’s aim is never simply a faithful historical analysis of the biblical text according to the human author’s original intention” (10 n. 31). Thus it seems that one could understand Aquinas to be engaging in a reverential reading, in which, whether fully aware of it or simply unconcerned, he might assist Paul to reach a true conclusion that Paul himself might not recognize. For readers not already devoted to Aquinas, it could be even more helpful to show his contribution than simply to establish that he was not wrong about the essence of Paul’s intended teaching despite not reading Paul in his own historical context. In the second essay, Markus Bockmuehl, considers “Aquinas on Abraham’s Faith in Romans 4.” He encourages biblical scholars, noting that once they look past the unfamiliar Aristotelian form of highly structured presentation, they will find a careful exegete at work who repeatedly allows his critical questions to be both generated and addressed by a close reading of the biblical text. Bockmuehl asks whether only the uncircumcised Abraham is the forefather of faith in Christ or whether the circumcised Abraham might also be BOOK REVIEWS 651 (39). He notes that in Genesis we can see that Abraham is the chief example of faith-based righteousness, because before he was ever circumcised, he believed in God, and God credited this to him as righteousness (40). Thus Abraham is the father of the covenant for both Jews and Gentiles (42). Bockmuehl suggests that Calvin might even have been able to approve of Aquinas’s explanation of faith and works where it is recognized that a man’s works are not proportioned to cause the habit of righteousness but rather a man must be justified inwardly by God first so that he can perform works proportioned to divine glory (42). Chapter 3 presents Hans Boersma’s contribution of “Ressourcement of Mystery: The Ecclesiology of Thomas Aquinas and the Letter to the Romans.” Boersma follows Yves Congar’s argument that Aquinas’s ecclesiology can serve as a trustworthy source to which we can return in order to find a bridge between Catholic and Protestant theology. Boersma quotes Congar’s assessment that Aquinas holds a happy medium between the Reformation and Jesuitical Romanism—the former neglecting the structure of the Church...

Surface Tensions: Framing the Flow of a Poetry-Film Collaboration

The article is a record of collaboration between a poet and a filmmaker – one undertaken under several people's gaze, becoming aware of itself through the perspectives of the visual and the verbal artist, of the critic and creative maker. It observes the process from the poet's and the filmmaker's sides of the interface, in the language and thought processes that come naturally to each, exploring particularly the use of metaphor to throw light upon the collaborators' investigation of poetry-film. As the project progressed it revealed the tensions between the participants' allegiance to the idea of collaboration and the urge to retain control of one's own medium and ways of working. Tracking the collaboration throughout each stage of development, from initial conversations, through false turns and periods of apparent impasse, the article records the inputs and shifts that led to a final synthesis and publication in an unexpected form.

From Kuramoto to Crawford: exploring the onset of synchronization in populations of coupled oscillators

The Kuramoto model describes a large population of coupled limit-cycle oscillators whose natural frequencies are drawn from some prescribed distribution. If the coupling strength exceeds a certain threshold, the system exhibits a phase transition: some of the oscillators spontaneously synchronize, while others remain incoherent. The mathematical analysis of this bifurcation has proved both problematic and fascinating. We review 25 years of research on the Kuramoto model, highlighting the false turns as well as the successes, but mainly following the trail leading from Kuramoto’s work to Crawford’s recent contributions. It is a lovely winding road, with excursions through mathematical biology, statistical physics, kinetic theory, bifurcation theory, and plasma physics.

Diffusion indexes and a statistical test for predicting turning points in business cycles

This paper presents a non-econometric statistical procedure for testing the significance of turning points in a sample diffusion index of leading indicators, allowing one to make inferences with respect to turning points of the corresponding business cycle. The procedure is applied utilizing 30 leading indicators in the prediction of peaks and troughs in the U.S. business cycle between 1969 and 1982. For this time period, the procedure correctly predicts the four peaks and the four troughs in the U.S. business cycle with a lead time range of from zero to twelve months, although false turns with respect to the prediction of peaks were recorded. This procedure compares very favorable with the Neftci non-econometric statistical test approach for predicting turning points in business cycles. Further, this procedure may be used in conjunction with smoothing and weighting techniques for improving predictions from leading indicators.

A new algorithm for finding the peptide chain turns in a globular protein

An algorithm is presented to identify peptide chain turns from X-ray-elucidated co-ordinate data. Chain turns are those regions in a globular protein where the backbone is folded back upon itself. The concept of a turn is important both because turns constitute recognizable structural units in proteins and because turns are situated at the solvent-accessible surface of the molecule. Current algorithms for turn identification are highly operational in character, often finding false turns and omitting actual ones. The algorithm presented here uses only the C-alpha co-ordinates for every residue in the protein. No other information of any kind is required, and notions about hydrogen bonding at these loci are irrelevant to the geometric nature of the argument. In this sense, the algorithm provides an objective criterion for the recognition of turns as strictly structural components in proteins. The algorithm is used to find the turns in a test set of proteins. Results of this application are in excellent agreement with visual turn identification from physical models.

CONTROL OF DRAFTING BY AIR FALSE TWISTER (II)

In the preceding paper (I), the ability of air twister tube as a substitute for usual twister tube of woollen ring spinning frame was studied.The effects of draft ratio, air pressure and tube dimension on false turns were experimented.The same testing apparatus as in the preceding paper was used in this experiment. The relation between irregularity of sliver and drafting condition-tube position, ratch, thread angle, etc-was investigated. The experimental results suggest the capability of the high drafting of condensed slubbing.The results obtained are as follows.1. The irregularity of slubbing drafted by using air twister tube has the same order as usual false twister. (Figs. 3, 4) These results substantiate the possibility of air twister.2. The tube setting should be decided by fiber length of the condensed slubbing. Each curve of Figs. 5 and 6 has a minimum value at the point of the longest fiber. Getting the ratch short, the irregularity is slightly reformed, and so, the long ratch as the woollen mule spinning is not necessarily reasonable. (Fig. 7)3. Applying air false twister, drafting with 2_??_3 zone is able to draft higher the woollen slubbing than usual single zone. In this case, the draft ratio of each zone should be limited within the range of CVa/CVb<1.

CONTROL OF DRAFTING BY AIR FALSE TWISTER (1)

In the preceding paper (I), the ability of air twister tube as a substitute for usual twister tube of woollen ring spinning frame was studied.The effects of draft ratio, air pressure and tube dimension on false turns were experimented.The same testing apparatus as in the preceding paper was used in this experiment. The relation between irregularity of sliver and drafting condition-tube position, ratch, thread angle, etc-was investigated. The experimental results suggest the capability of the high drafting of condensed slubbing.The results obtained are as follows.1. The irregularity of slubbing drafted by using air twister tube has the same order as usual false twister. (Figs. 3, 4) These results substantiate the possibility of air twister.2. The tube setting should be decided by fiber length of the condensed slubbing. Each curve of Figs. 5 and 6 has a minimum value at the point of the longest fiber. Getting the ratch short, the irregularity is slightly reformed, and so, the long ratch as the woollen mule spinning is not necessarily reasonable. (Fig. 7)3. Applying air false twister, drafting with 2_??_3 zone is able to draft higher the woollen slubbing than usual single zone. In this case, the draft ratio of each zone should be limited within the range of CVa/CVb<1.