Unipolar Type Research Articles

A novel bipolar coil structure with high interoperability performance for electric vehicle wireless charging systems

SummaryThe magnetic couplers play an important role in electric vehicle (EV) wireless power transfer (WPT) systems. Conversational coupling structures are mainly based on unipolar, bipolar, and quadrupole coils, and the interoperability among them cannot be achieved. To solve the interoperability problem in the coupling structure, a novel bipolar coil structure is proposed in this paper. Energy transfer with unipolar and bipolar coils is achieved by interconnecting unipolar and bipolar types crosswise in the same plane and combining them with the corresponding topologies. They are connected in series on the dc side. An experimental prototype is built to verify the interoperability performance of the proposed novel bipolar coil structure. The proposed novel bipolar coil structure can be compatible with unipolar, bipolar, and quadrupole coils and achieve a maximum dc‐dc efficiency of more than 85%.

Coupling coordination and influencing factors of urban spatial accessibility and economic spatial pattern in the New Western Land-Sea Corridor.

The construction of the New Western Land-Sea Corridor is crucial to the economic development of western China and even Southeast Asia. Research analyzes the evolution of urban economic spatial pattern of the New Western Land-Sea Corridor in different years and discusses the coordinated development between economic connection and accessibility and its influencing factors. The research results show that: First, the influence of labor force on the urban centrality of the New Western Land-Sea Corridor is gradually increasing, and the spatial pattern of the urban network has gradually shifted from a unipolar attraction type to a spatial pattern of "one main and multiple subordinates." Second, urban accessibility presents a "core-periphery" spatial pattern, and the coupling coordination degree presents the spatial characteristics of "centro-periphery." The economic correlation strength, spatial accessibility, and the coordinated distribution of the two all have obvious spatial agglomeration characteristics. Third, there are spatial differences in the influencing factors of the coupling coordination degree. Based on this, the research puts forward the development mode of "growth pole," "area," and "axis," attaches importance to the problems of labor force in urban development, and strengthens the level of coupling coordination between regional transportation and economy, to promote the integration of regional transportation, logistics, and economy.

Top electrode dependent resistive switching in M/ZnO/ITO memristors, M = Al, ITO, Cu, and Au

Resistive random access memory or memristive devices has emerged as a new paradigm for non-volatile memory and neuromorphic systems due to low power consumption, smaller footprint, and ultra-fast operation. This paper reports the dependency of top electrode on the resistive switching behavior of ZnO memristive devices. ZnO based memristor with ITO bottom electrode and Al, ITO, Cu or Au as top electrode were fabricated using room temperature radio frequency sputtering. Thickness of the ZnO layer was optimized for Al/ZnO/ITO device structure. Both filament type and interface type resistive switching mechanisms were observed in the devices by changing the top electrode material. Valance change mechanism (VCM) and electrochemical metallization (ECM) were observed in filament type resistive switching depending the type of the top electrode. Al, ITO, and Cu top electrode devices showed bipolar and filament type resistive switching. Unipolar and interface type resistive switching was realized in gold top electrode (Au/ZnO/ITO) device. The conduction mechanisms in these memristors were also investigated.

Analysis of Lightning-Induced Voltages on a Matched Experimental Overhead Line

This article presents an analysis of 64 lightning-induced voltage waveshapes recorded on a 2.7 km long, nonenergized experimental line located on the campus of the University of São Paulo, São Paulo, Brazil. The line had two conductors separated by 6 m crossarms; one was equipped with surge arresters, whereas the other was unprotected. The data presented in this article refer to the unprotected conductor, which was matched at both ends. Although, strictly speaking, all the recorded voltages were bipolar, they were classified into four categories and the parameters which characterize each type are presented and discussed. About 67.2% of the induced voltages were classified as unipolar (Type I) and, except for one case, all of them had positive polarity. About 20.3% of the voltages were classified as Type II, whose waveshape is composed of two semicycles, the first one of positive polarity. About 9.4% of the recorded voltages were classified as Type III, whose waveshape is also composed of two semicycles, but the first one which a much shorter duration and lower magnitude. Only 3.1% were classified as Type IV, whose waveshape has three semicycles and the peak value occurs in the third one, which has negative polarity and the longest duration.

Gas Discharge Atmospheric Pressure Systems for the Biomedical Use

The analysis of world literature is carried out, which indicates the intensive development of the scientific and technical field “Plasma in Medicine” based on the use of different gas-discharges for biomedical purposes. The atmospheric pressure plasma discharge systems have the favorite features and are very suitable for medical physiotherapy, bactericide treating and even for sterilization. The systems with non-thermal plasma are in the most use and one of their applications is generation of gas ozone. The given paper is devoted to looking for atmospheric pressure discharge modes, which are more suitable for ozone therapy equipment taking into account the peculiarities of such type of electronic apparatus. As practice shows, for the generation of ozone, discharges with a secondary-emission cathode and non-thermal plasma are most preferable, and of these two types of discharges are discharges with a dielectric barrier and corona discharges with uncoated metal electrodes. The article focuses on the appropriateness of the use of a corona discharge for ozone therapy equipment. This is justified by the fact that the corona discharge ozonizers have certain design advantages over the ozonizers on the discharge with dielectric barriers, namely that the advantages of the ozonizers on the corona discharge are the absence of a expensive barrier and low resistance to the gas flow, so there is no need to significantly increase the pressure at the ozonizer oxygen inlet, and possibility of power supplying the ozonizer with DC voltage. Also, ozonizers on the corona discharge have a lower cost. From the literature and the authors' own practice, there is a wide variety of configurations of electrode systems for creating the corona discharge, but they always have electrodes with a small radius of curvature of the surface: threads, wires, nets, various pointed needles, serrated electrodes. The article considers the physical mechanism of maintaining the corona discharge of a unipolar or bipolar type and notes the role of secondary electron emission of the cathode. All types of corona discharge are capable of generating ozone because discharge electrons have the energy required to dissociate oxygen molecules in a non-thermal gas environment. Then a free oxygen atom attaches to an oxygen molecule to form a metastable ozone molecule. It is noted that the corona discharge and ozone generation were studied in detail mainly in unipolar point-of-plane or wire-in-pipe systems. The data on ozone generation in bipolar discharge is not enough to develop an ozone therapy apparatus, although this form of discharge is interesting because it requires relatively small values of the supply voltage and operates at a direct current. Based on the review of the prospects for the use of bipolar corona discharge in biomedical apparatus and practical considerations of the realistic and expanded future usage of bipolar corona equipment in the ozone therapy, the tasks have been formulated to be solved. It is necessary to thoroughly study the characteristics of the developed equipment and the influence of various external operational factors and physico-chemical processes in the ozonizer electrode system on them. It is necessary to ensure that the parameters of the equipment are maintained during operation, which means that during the eight-hour working day and with the total time between failures of at least 1000 hours. Also, it is necessary to take into account the effect of the decomposition of ozone molecules at elevated temperatures and not to allow excessive heating of the ozonizer. These requirements must be met by choice of the configuration and materials of the electrode system and must be experimentally verified. It is proposed to ensure the linearity of the calibration characteristics of the ozonizer and to formalize it mathematically to simplify the setting and maintenance of stable operating modes of ozone equipment. It is necessary to prove its therapeutic efficacy, including for sterilization treatment, with the participation of medical specialists.

Neuronal diversity, dendro-spinous characterization in the hippocampal complex of Coracias benghalensis

Coracias benghalensis, a seasonally breeding sub-tropical bird, displays a peculiar rolling behavior to attract the female for courtship and territoriality. The avian hippocampal complex (HCC) is a dorsomedial component of the forebrain and is involved in cognitive functions and sexual behavior. The present study was aimed to identify and characterize the neuronal classes, dendritic arborization, and spines density in the HCC of C. benghalensis during the quiescent phase of the breeding cycle. Adult male birds were collected during the winter season from a wild zone of Prayagraj (25?? 28??? N, 81?? 54??? E), U.P., India. These birds were transcardially perfused, and whole brains were stained with Cresyl-violet and Golgi-Colonnier staining method. We observed unipolar, bipolar, pyramidal, and multipolar types of projection neurons and local circuit (aspinous) neurons with a qualitative and quantitative characterization of soma size, dendritic arborization, and spine density. The multipolar neurons with the highest spine density were predominantly present in the HCC of C. benghalensis. This study concludes that the bird???s neuronal diversity and neuronal characteristics suggest a unique character that helps the bird perform overt rolling behavior as functional (learning and memory) intervention of the HCC.

A Novel Approach on the Unipolar Axial Type Eddy Current Brake Model Considering the Skin Effect

The braking torque mathematical modelling in electromagnetic eddy current brake (ECB) often ignores the skin effect that occurrs during operation. However this phenomenon can not be simply neglected. Therefore, this paper presents a mathematical model of braking torque for a unipolar axial type of ECB system with a non-magnetic disk, which considers the skin effects. The use of mathematical models that consider the existence of skin effects is significant in approaching the braking torque according to the actual condition. The utilization of generic calculations to the model of the ECB braking torque leads to invalid results. Hence, in this paper, the correction factor was added to improve the braking torque calculation as a comparator to the proposed equation. However, the modification and addition of the correction factor were only valid to estimate the low-speed regimes of torque, but very distant for the high-speed condition. From the comparison of calculated values using analytical and 3D modelling, the amount of braking torque at a low speed was found to have an average error for the equation using a correction factor of 1.78 Nm, while after repairing, a value of 1.16 Nm was obtained. For the overall speed, an average error of 14.63 Nm was achieved, while the proposed equation had a small difference of 1.79 Nm. The torque difference from the calculation results of the proposed model with the measurement value in the experiment was 4.9%. Therefore, it can be concluded that the proposed equation provided a better braking torque value approach for both low and high speeds.

Резистивное переключение в мемристорах на основе гетероструктур Ag/Ge/Si

It is shown that two modes of resistive switching – bipolar and volatile unipolar – are peculiar for the Ag/Ge/Si structures with germinating dislocations in the germanium layer. In this modes the structures have stable states of electric current with ION/IOFF ~1.5–2.7. The volatile unipolar type of switching can be caused by the capture of charge carriers to deep levels associated with lattice defects in the Ge film of the memristor. At the same time, bipolar switching is associated with the drift of Ag+ ions along germinating dislocations.

Magnetic Field Effect on Critical Current of Different Structural HTS DC Cables

High-temperature superconducting (HTS) dc cables become viable for future dc electric power transmissions due to their low loss, light weight, high current density, and high transmission capacity. According to the structure, HTS dc cables are commonly divided into unipolar, bipolar coaxial and multicore types. The HTS critical current is magnetic field dependent, while different HTS dc cable structures have different field distribution features. The influence of different HTS dc cable structures on the critical current is analyzed and compared, in order to provide a basis for the design of a practical HTS dc cable.

Hemiarthroplasty in Complex Proximal Humeral Fractures Is uncemented methaphyseal corundum blasted titanium humeral stem an efficent alternative?

The aim of this experimental study is to reveal the design and characteristics of unipolar shoulder prosthesis type Arrow (Groupe FH�, France) as well as to evaluate the outcome of the proximal humerus fracture treated with this implant. 8 patients with a mean age of 62.5 years were operated with immediate passive rehabilitation and active exercises initiated around day 45. All patients had good results with minimal pain, a mean Constant - Murley score of 74 and an acceptable shoulder amplitude. The clinical success was assured by the anatomic union of the tuberosities around the implant. The Arrow metaphyseal corundum blasted humeral titanium stem assures a perfect osseointegration with optimal stability and is an efficient alternative for shoulder hemiarthroplasty.

Mass Emotion and Shared Feelings

Abstract Are mass emotions and shared feelings two different phenomena? In this paper, I investigate two different forms of corporeal interaction; one bipolar and one unipolar. In the bipolar type, two individuals give different impulses, which are aligned with each other. In the unipolar type, the impulse derives from a thing, a task or a person. This impulse creates an identical corporeal dynamic in those involved. This synchronization of the corporeal directions leads to corporeal resonance and a reciprocal intensification. The shared experience of feelings is a part of unipolar corporeal interaction since the impulse for the corporeal dynamic of the individuals departs from one and the same feeling. According to Max Scheler’s analysis of emotional contagion, contagion comes about through imitation; it is merely a fallacy to believe the other person’s feeling is one’s own. In this paper, I argue that emotional contagion and shared feelings cannot be distinguished by virtue of this criterion of genuineness and instead belong to the same type of corporeal interaction. On the whole, I question the assumption that feelings are solely personal states. Individual and collective feelings can only be distinguished unambiguously through concepts, whereas affective phenomena are always tied to others, to norms and discourse.

An All-Organic Composite System for Resistive Change Memory via the Self-Assembly of Plastic-Crystalline Molecules.

An all-organic composite system was introduced as an active component for organic resistive memory applications. The active layer was prepared by mixing a highly polar plastic-crystalline organic molecule (succinonitrile, SN) into an insulating polymer (poly(methyl methacrylate), PMMA). As increasing concentrations of SN from 0 to 3.0 wt % were added to solutions of different concentrations of PMMA, we observed distinguishable microscopic surface structures on blended films of SN and PMMA at certain concentrations after the spin-casting process. The structures were organic dormant volcanos composed of micron-scale PMMA craters and disk type SN lava. Atomic force microscopy (AFM), cross-sectional transmission electron microscopy (TEM), scanning electron microscopy (SEM), and energy dispersive X-ray spectrometer (EDX) analysis showed that these structures were located in the middle of the film. Self-assembly of the plastic-crystalline molecules resulted in the phase separation of the SN:PMMA mixture during solvent evaporation. The organic craters remained at the surface after the spin-casting process, indicative of the formation of an all-organic composite film. Because one organic crater contains one SN disk, our system has a coplanar monolayer disk composite system, indicative of the simplest composite type of organic memory system. Current-voltage (I-V) characteristics of the composite films with organic craters revealed that our all-organic composite system showed unipolar type resistive switching behavior. From logarithmic I-V characteristics, we found that the current flow was governed by space charge limited current (SCLC). From these results, we believe that a plastic-crystalline molecule-polymer composite system is one of the most reliable ways to develop organic composite systems as potential candidates for the active components of organic resistive memory applications.

Memristive properties of In2O3/LaNiO3 heterostructures grown by pulsed laser deposition

Resistance switching properties of nanostructured In2O3 films grown on LaNiO3 (LNO) bottom electrode (BE) have been investigated for non volatile memory applications. Ag/In2O3/LNO/SiO2 heterostructures were fabricated by pulsed laser deposition. Polycrystalline growth of oxides LNO and In2O3 was confirmed by GIXRD, while AFM show nanostructured growth with smooth surface morphology. Two terminal I–V characteristics showed reproducible two distinct resistance states in the film and unipolar type switching. Typical resistance switching ratio (R on /R off ) of the order of 112 % has been estimated at room temperature. A possible mechanism of the formation and rupture of conducting filament is proposed based on the Joule heating effect with external electron injection at the Ag/In2O3 top interface, whereas the LNO BE acts as oxygen reservoir at the In2O3/LNO interface.

Resistive Switching Characteristics of Si-Rich Oxides with Embedding Ti Nanodots

Resistive random access memories (ReRAMs) have been intensively studied as potential candidates for the next generation of memory devices due to their simplicity in structure. Among various switching materials, Si-rich oxide (SiOx) has been received much attention from the viewpoint of the good compatibility to the current Si-ULSI technology. So far, we have studied resistance switching behaviors of SiOx sandwiched with Pt and/or Ni electrodes caused by formation of conducting filament path presumably due to the oxygen deficiency [1, 2]. In addition, from local I-V measurements performed by contacting a single Ni-nanodots (NDs) as a top electrode with a Rh coated-AFM tip, we have confirmed the size scalability of SiOx as a resistive switching material. However, to realize low power switching operation, one of the major concerns is the control of the formation of the conductive filament paths in SiOx. In this work, we have expected that NDs can trigger the formation of the conductive filament path in SiOx, and evaluated an impact of NDs embedding into SiOxon the switching characteristics. MIM diodes consisting of Ni electrodes and SiOx in which Ti-NDs were embedded were fabricated on SiO2/Si(100) by electron beam (EB) deposition and surface treatment using a remote plasma of pure H2 (H2-RP) as follows: At first, a ~15 nm-thick Ni layer was formed as a bottom electrode and followed by the EB deposition of a ~1 nm-thick SiOx layer. And then, Ti-NDs were formed by a combination of a Ge(20 nm)/Ti(3 nm) stacked layer formation and subsequent H2-RP exposure without external heating [3], where Ge layer was used as a barrier layer against oxidation of the ultrathin Ti layer. During the H2-RP exposure, H2 gas pressure and VHF power of a 60 MHz generator were maintained at 24 Pa and 500 W, respectively. After the H2-RP exposure, a ~8 nm-thick SiOx layer and then Ni top electrodes were formed by EB deposition. We also fabricated Ni/SiOx/Ni-MIM diodes without NDs as references. AFM observations showed the formation of Ti-NDs with an areal density as high as 3.3×1011cm-2 was taken after H2-RP exposure. XPS analysis confirmed that the Ge layer was completely etched away by H2-RP exposure and surface oxidation of Ti-NDs proceeds during air exposure. Resistive switching characteristics of SiOx with and without NDs were measured from I-V curves in voltage sweep mode (Figs. 1(a) and (b)). In both cases, a distinct unipolar type resistive-switching was repeatedly observed. However, SET and RESET voltages were well separated by embedding NDs. These results indicate that the NDs in SiOx are likely to act as a trigger for the formation of conductive path in a reproducible fashion. Also, the resistances in high and low resistance states (HRS and LRS) calculated from the current levels at -0.1 V were summarized as functions of the switching cycle (Fig. 2). Obviously, for the diodes with NDs, a stable resistive switching was repeatedly observed in comparison with the diodes without NDs. With embedding NDs, the variations in the resistance of both ON and OFF states became large markedly, and the ON/OFF ratio in resistance was increased from 45 to 150, which indicates that the Ti oxide formed at embedded Ti-NDs surface reduces the current levels through the SiOx. In summary, the embedding of Ti-based NDs in SiOxis very effective to separate the operation voltages between SET and RESET voltages and to increase in the ON/OFF ratio in resistance. Acknowledgements This work was supported in part by Young Scientists (A) No. 15H05520 from the Ministry of Education, Culture, Sports, Science and Technology, Japan and by JSPS Core-to-Core Program of International Collaborative Research Center on Atomically Controlled Processing for Ultra large Scale Integration. References 1) A. Ohta, et al, Jpn. J. Appl. Phys., 52(2012) 06FF02. 2) A. Ohta, et al, IEICE TRANSACTIONS on Electronics, E96-C(2013) 702. 3) K. Makihara, et. al, J. Optoelectronics and Adv. Materials, 12 (2010) 626. Figure 1

Dopant-Free CMOS on SOI: Multi-Gate Si-Nanowire Transistors for Logic and Memory Applications

In CMOS technology, NMOS- and PMOS-FETs are hardware defined by choosing the appropriate doping of source (S) and drain (D) junctions with respect to the substrate. However, in this work we report on a novel CMOS multi-gate (MG) nanowire field-effect transistor (NWFET) architecture on silicon-on-insulator (SOI) material which is virtually free of doping. The fabricated MG-NWFETs are originally ambipolar nanowire devices with midgap Schottky-barriers serving as S/D contacts. A tri-gate structure is used as front-gate for current control across the NWFET whereas a planar back-gate is used to select the desired unipolar device type (i.e. NMOS or PMOS) via field-induced accumulation of electrons or holes, respectively. Both, logic and memory devices can be realized with the same simple nanowire structure.

SISTEM APLIKASI MONITORING RUANGAN BERBASIS WEBCAM

Software design and hardware application system monitoring room webcam based aims to add value to the webcam to be used as part of the security system, implementing the work process of hardware and software monitoring system formed using delphi 7, analyzing the performance o f a stepper motor as the driving platform webcam and documenting object images and sounds in the room activities into a file format AVI (Audio Video Interleave). Webcams are used in this design is equipped with a standard webcam lighting lamps LED (Light Emitting Diode) with a USB data line, while the driver controls the webcam in the design o f this platform using unipolar type stepper motor controlled by a microcontroller, motor drivers and line interface RS232 to USB (Universal Serial Bus) converter. The installation o f the webcam to webcam platform play will lead to the right, left, stop rotating right and or to the left automatically. From the test results it can be concluded that the monitoring system and webcam based indoor stepper motor consists o f webcam applications and motor control applications platform which is separately because both applications use the USB and COM communication channels are opened simultaneously. As for the results o f the motion setting webcam platform proved to have a consistent degree of deviation for the wine and left turn kenanan but still require a series o f additional gears for smooth movement o f the platform and to reduce the effects o f shadow on motion pictures.

Characterization of Resistance-Switching Properties of SiOx Films Using Pt Nanodots Electrodes

Pt-NDs as nano-electrodes were formed on SiOx/TiN stacked structures by exposing an ultrathin Pt layer to remote H2-plasma without external heating and evaluate the scalability of SiOx by using a conductive AFM probe technique. AFM images confirm the formation of Pt-NDs with an areal dot density of ~1.5×10^10 cm-2 as a result of surface migration and agglomeration of Pt atoms promoted by the surface recombination of H radicals. By contacting a single Pt-ND with a Rh coated Si cantilever and applying positive bias with respect to the TiN bottom electrode, the uni-polar type resistance switching behavior was observed in despite of contact area between the ND and the SiOx as small as ~900 nm^2. In addition, after electro-forming process, distinct bi-polar type resistive switching of counter-clockwise rotation was also confirmed repeatedly by sweeping positive bias applied to Pt-ND, which suggests that plasma damages is negligibly small.

Hemiarthroplasties in young patients with osteonecrosis or a tumour of the proximal femur; an observational cohort study

BackgroundThe failure scenario in total hip arthroplasty (THA), in younger patients, is dependent on the fixation and wear of the acetabular component. In selected cases, where endoprosthetic replacement of the femoral head is unavoidable for limb salvage or functional recovery, hemiarthroplasty can be chosen as an alternative. The purpose of this study is to evaluate hemiarthroplasty as treatment strategy for young patients with osteonecrosis or a tumour of the proximal femur.MethodsBetween 1985 and 2008, 42 hemiarthroplasties (unipolar and bipolar) were performed in patients younger than 65 years with osteonecrosis (n=13) or a tumour of the proximal femur (n=29). All patients were seen at yearly follow-up examination and evaluated. Revision or conversion to a THA was regarded as a failure of the implant. A Kaplan Meier analysis was performed. To determine significant differences between categorical groups, the Pearson chi-square test was used. In numerical groups the independent T-test and One-way ANOVA were used.ResultsAfter a mean follow-up of 7.1 years, failure of the hemiarthroplasty occurred 6 times. The Kaplan Meier survival analysis with conversion to THA or revision as endpoint of the bipolar hemiarthroplasties (n=38) shows a 96% survival at 15, and 60% at 20 years. In the unipolar type (n=4) we found a conversion rate of 50% within 3 years.ConclusionsBipolar hemiarthroplasty is a reasonable alternative in a young patient with osteonecrosis or a tumour of the proximal femur as indication. Because of the high conversion rate after unipolar hemiarthroplasties, we would not recommend this type of prosthesis in the young patient.

CMOS without Doping on SOI: Multi-Gate Si-Nanowire Transistors for Logic and Memory Applications

In CMOS technology, NMOS- and PMOS-FETs are hardware defined by choosing the appropriate doping of source (S) and drain (D) junctions with respect to the substrate. However, in this work we report on a novel CMOS multi-gate (MG) nanowire field-effect transistor (NWFET) architecture on silicon-on-insulator (SOI) material which is virtually free of doping. The fabricated MG-NWFETs are originally ambipolar nanowire devices with midgap Schottky-barriers serving as S/D contacts. A tri-gate structure is used as front-gate for current control across the NWFET whereas a planar back-gate is used to select the desired unipolar device type (i.e. NMOS or PMOS) via field-induced accumulation of electrons or holes, respectively. Both, logic and memory devices can be realized with the same simple nanowire structure.

Evaluation of Chemical Composition and Bonding Features of Pt/SiO<sub>x</sub>/Pt MIM Diodes and Its Impact on Resistance Switching Behavior

We have investigated the impact of O2 annealing after SiOx deposition on the switching behavior to gain a better understanding of the resistance switching mechanism, especially the role of oxygen deficiency in the SiOx network. Although resistive random access memories (ReRAMs) with SiOx after 300°C annealing sandwiched with Pt electrodes showed uni-polar type resistance switching characteristics, the switching behaviors were barely detectable for the samples after annealing at temperatures over 500°C. Taking into account of the average oxygen content in the SiOx films evaluated by XPS measurements, oxygen vacancies in SiOx play an important role in resistance switching. Also, the results of conductive AFM measurements suggest that the formation and disruption of a conducting filament path are mainly responsible for the resistance switching behavior of SiOx.