Multilayer ferrite inductors for the use at high temperatures

2020 ◽  
Vol 37 (2) ◽  
pp. 73-78 ◽  
Author(s):  
Heike Bartsch ◽  
Sebastian Thiele ◽  
Jens Mueller ◽  
Dirk Schabbel ◽  
Beate Capraro ◽  
...  
Keyword(s):  
High Temperature ◽  
High Performance ◽  
Content Type ◽  
Ferrite Material ◽  
Nickel Copper ◽  
Copper Zinc ◽  
Higher Temperature ◽  
Silver Palladium ◽  
Increasing Temperature ◽  
First Time

Purpose This paper aims to investigate the usability of the nickel copper zinc ferrite with the composition Ni0.4Cu0.2Zn0.4Fe1.98O3.99 for the realization of high-temperature multilayer coils as discrete components and integrated, buried function units in low temperature cofired ceramics (LTCC). Design/methodology/approach LTCC tapes were cast and test components were produced as multilayer coils and as embedded coils in a dielectric tape. Different metallization pastes are compared. The properties of the components were measured at room temperature and higher temperature up to 250°C. The results are compared with simulation data. Findings The silver palladium paste revealed the highest inductance values within the study. The measured characteristics over a frequency range from 1 MHz to 100 MHz agree qualitatively with the measurements obtained from toroidal test samples. The inductance increases with increasing temperature and this influence is lower than 10%. The characteristic of embedded coils is comparable with this of multilayer components. The effective permeability of the ferrite material reaches values around 130. Research limitations/implications The research results based on a limited number of experiments; therefore, the results should be verified considering higher sample sizes. Practical implications The results encourage the further investigation of the material Ni0.4Cu0.2Zn0.4Fe1.98O3.99 for the use as high-temperature ferrite for the design of multilayer coils with an operation frequency in the range of 5-10 MHz and operation temperatures up to 250°C. Originality/value It is demonstrated for the first time, that the material Ni0.4Cu0.2Zn0.4Fe1.98O3.99 is suitable for the realization of high-temperature multilayer coils and embedded coils in LTCC circuit carriers with high performance.

HIGH TEMPERATURE ULTRA HIGH VOLTAGE SIC THYRISTORS

2010 ◽  
Vol 2010 (HITEC) ◽  
pp. 000167-000173
Author(s):  
R. Singh ◽  
S. Creamer ◽  
E. Lieser ◽  
S. Jeliazkov ◽  
S. Sundaresan
Keyword(s):  
High Temperature ◽  
Voltage Drop ◽  
Carrier Lifetimes ◽  
Edge Termination ◽  
Minority Carrier Lifetimes ◽  
Stable Performance ◽  
Switching Characteristics ◽  
High Yields ◽  
Increasing Temperature ◽  
First Time

Through a systematic study, Silicon Carbide Gate Turn Off (GTO) Thyristors with record performance are demonstrated. Several Anode-Gate interdigitation schemes (raster, hex and involute) were explored to investigate their effect on the static as well as switching characteristics. An optimized edge-termination was employed that resulted in the achievement of near-theoretical forward blocking voltages (>8.1kV), and high yields (>60% on 8mm×8mm) on GTO Thyristors with 60μm/5×1014 cm−3 voltage-blocking epitaxial layers. A low differential specific on-resistance of 2.55 mΩ-cm2, and low on-state voltage drop were measured at 500 A/cm2. High Temperature forward I-V and reverse I-V characteristics show extremely stable performance with temperature, in contrast to state-of-the-art Si GTO Thyristors. Turn-on transient characteristics show a stable delay time of about 400 nano-seconds, and a rise-time that decreases with increasing temperature. Detailed high temperature turn-off measurements conducted using Anode-Switched mode was used to extract the value of minority carrier lifetimes as a function of temperature for the first time.

RBF-based mesh morphing approach to perform icing simulations in the aviation sector

2019 ◽  
Vol 91 (4) ◽  
pp. 620-633 ◽  
Author(s):  
Corrado Groth ◽  
Emiliano Costa ◽  
Marco Evangelos Biancolini
Keyword(s):  
High Performance ◽  
Three Dimensional ◽  
Ansys Fluent ◽  
Content Type ◽  
Mesh Morphing ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Analyses ◽  
2D And 3D ◽  
First Time ◽  
Practical Implications

Purpose Numerical simulation of icing has become a standard. Once the iced shape is known, however, the analyst needs to update the computational fluid dynamics (CFD) grid. This paper aims to propose a method to update the numerical mesh with ice profiles. Design/methodology/approach The present paper concerns a novel and fast radial basis functions (RBF) mesh morphing technique to efficiently and accurately perform ice accretion simulations on industrial models in the aviation sector. This method can be linked to CFD analyses to dynamically reproduce the ice growth. Findings To verify the consistency of the proposed approach, one of the most challenging ice profile selected in the LEWICE manual was replicated and simulated through CFD. To showcase the effectiveness of this technique, predefined ice profiles were automatically applied on two-dimensional (2D) and three-dimensional (3D) cases using both commercial and open-source CFD solvers. Practical implications If ice accreted shapes are available, the meshless characteristic of the proposed approach enables its coupling with the CFD solvers currently supported by the RBF4AERO platform including OpenFOAM, SU2 and ANSYS Fluent. The advantages provided by the use of RBF are the high performance and reliability, due to the fast application of mesh smoothing and the accuracy in controlling surface mesh nodes. Originality/value As far as authors’ knowledge is concerned, this is the first time in scientific literature that RBF are proposed to handle icing simulations. Due to the meshless characteristic of the RBF mesh morphing, the proposed approach is cross solver and can be used for both 2D and 3D geometries.

Parametric study on tensile and flexural properties of ULTEM 1010 specimens fabricated via FDM

2021 ◽  
Vol 27 (2) ◽  
pp. 429-451
Author(s):  
Chrysoula Pandelidi ◽  
Tobias Maconachie ◽  
Stuart Bateman ◽  
Ingomar Kelbassa ◽  
Sebastian Piegert ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Process Parameters ◽  
Computer Aided Design ◽  
High Performance ◽  
Mechanical Performance ◽  
Fused Deposition Modelling ◽  
Controlled Cooling ◽  
Content Type ◽  
Fused Deposition

Purpose Fused deposition modelling (FDM) is increasingly being explored as a commercial fabrication method due to its ability to produce net or near-net shape parts directly from a computer-aided design model. Other benefits of technology compared to conventional manufacturing include lower cost for short runs, reduced product lead times and rapid product design. High-performance polymers such as polyetherimide, have the potential for FDM fabrication and their high-temperature capabilities provide the potential of expanding the applications of FDM parts in automotive and aerospace industries. However, their relatively high glass transition temperature (215 °C) causes challenges during manufacturing due to the requirement of high-temperature build chambers and controlled cooling rates. The purpose of this study is to investigate the mechanical properties of ULTEM 1010, an unfilled polyetherimide grade. Design/methodology/approach In this research, mechanical properties were evaluated through tensile and flexural tests. Analysis of variance was used to determine the significance of process parameters to the mechanical properties of the specimens, their main effects and interactions. The fractured surfaces were analysed by scanning electron microscopy and optical microscopy and porosity was assessed by X-ray microcomputed tomography. Findings A range of mean tensile and flexural strengths, 60–94 MPa and 62–151 MPa, respectively, were obtained highlighting the dependence of performance on process parameters and their interactions. The specimens were found to fracture in a brittle manner. The porosity of tensile samples was measured between 0.18% and 1.09% and that of flexural samples between 0.14% and 1.24% depending on the process parameters. The percentage porosity was found to not directly correlate with mechanical performance, rather the location of those pores in the sample. Originality/value This analysis quantifies the significance of the effect of each of the examined process parameters has on the mechanical performance of FDM-fabricated specimens. Further, it provides a better understanding of the effect process parameters and their interactions have on the mechanical properties and porosity of FDM-fabricated polyetherimide specimens. Additionally, the fracture surface of the tested specimens is qualitatively assessed.

The high performance organization: proposed definition and measurement of its performance

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
André de Waal
Keyword(s):  
Organizational Performance ◽  
High Performance ◽  
Peer Group ◽  
Research Question ◽  
General Definition ◽  
Common Denominator ◽  
Content Type ◽  
Definition Of ◽  
High Performance Organization ◽  
First Time

Purpose The purpose of this paper is to arrive at a general definition of an HPO and a (practical) way to measure an HPO. Managers are looking for techniques to strengthen their organizations in a way that they cannot only cope with threats but could also quickly take advantage of opportunities, and thus, grow and thrive. The academic and especially the practitioner fields reacted on this “thirst for high performance knowledge” with a plethora of books and articles on the topic of high performance organizations (HPOs). These publications each came with their own description and measurement of HPOs, which created a lot of confusion among practitioners. Design/methodology/approach In this study the following reserach question is answered: how can an HPO be defined and its performance measured? So that with the answer, this paper can take away the aforementioned confusion. This paper does this by conducting an extensive systematic review of the literature on HPO, after which this paper synthesizes the findings into a proposal on how to define and measure the HPO. Findings This paper was able to obtain from the literature a list of definitions and measurements for an HPO. The common denominator in these definitions and measurements turned out to be respondents given their opinion on the effects of the organizational practices they apply on organizational performance vis-à-vis that of competitors. This paper concluded therefore that an HPO should be defined and measured relative to competitors and should be based on the perception of managers and employees of the organization: An HPO is an organization that achieves results that are better than those of its peer group over a longer period of time. Research limitations/implications With the answer on the research question, this paper fills the current gap in the definition and measurement literature on HPOs, and thus, has moved the research into HPOs forward, as researchers can use these research results in their future studies on high performance and HPOs. Originality/value Although there is a plethora of literature on high performance and HPOs no univocal definition and measurement of the HPO can be found. This study provides for the first time an academically well-founded definition and measurement method.

High Temperature Ceramifying Behavior of SR/Al2O3 Composites

2010 ◽  
Vol 105-106 ◽  
pp. 168-170
Author(s):  
Yuan Lu Xiong ◽  
Qiang Shen ◽  
Fei Chen ◽  
Jin Zheng ◽  
Lian Meng Zhang
Keyword(s):  
Phase Transformation ◽  
High Temperature ◽  
Flexural Strength ◽  
Chemical Bonds ◽  
Fire Retardancy ◽  
Mullite Phase ◽  
Alumina Composites ◽  
Higher Temperature ◽  
Increasing Temperature ◽  
Silicone Content

In this work, silicone/alumina composites with 33 wt.% silicone content are prepared by compression mould technique. TGA, XRD and SEM were used to characterize the ceramifying behavior when the samples were heated from 600 to 1600°C. XRD results suggest that the ceramic residue of SR could restrain the phase transformation of γ-Al2O3 below 1100°C, indicating that the chemical bonds preserve the mechanism strength of SR/Al2O3 composites under high temperature. The flexural strength increases from 18.19 MPa to 75.31 MPa with the increasing temperature from 600 to 1600°C, owing to the sintering reaction between SiO2 and Al2O3 forming mullite phase under higher temperature. It has low liner shrinkage after firing and nearly no macrocracks or deformation under any temperature, illustrating that the SR/Al2O3 composites can be used as organic fire-retardancy materials.

Creating high performance partnerships in Asia: the case of NEH the Philippines

2019 ◽  
Vol 15 (1) ◽  
pp. 171-188
Author(s):  
André de Waal ◽  
Jeroen de Haas
Keyword(s):  
Value Chain ◽  
High Performance ◽  
Design Methodology ◽  
The Philippines ◽  
Content Type ◽  
A Value ◽  
Partner Firm ◽  
Asian Context ◽  
First Time

Purpose The purpose of this paper is to evaluate a previously developed framework for creating so-called high performance partnerships (HPPs), which yields a competitive advantage for all firms in the partnership, in the Asian context. Design/methodology/approach The HPP framework is evaluated for a Philippine organization that produces, markets and ships bananas in Asia. The evaluation entailed conducting a questionnaire, statistically redeveloping the framework and organizing several feedback workshops with the partner firms, the latter aiming to discuss and agree to improvements that each partner could implement to achieve high performance in the value chain. Findings The results showed that the evaluated HPP framework can be used to score the quality of each partner in the chain and to yield targeted recommendations to improve the performance of each partner firm. The subsequent application of the recommendations derived from applying the HPP framework created substantial profits for the partner firms. Originality/value Originally developed in a western context and applied to a value chain of European organizations, the HPP framework was successfully applied for the first time in the Asian context, to evaluate the performance of an Asian value chain and identify areas for improvement of the Asian partner firms. As such, the results contribute both to the HPP literature, filling a gap therein, and to practice, as Asian organizations can use with confidence a framework which has been validated in their context.

scholarly journals Initial Stage Carbonization of γ-Fe(100) Surface in C2H2 under High Temperature: A Molecular Dynamic Simulation

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5957
Author(s):  
Yu Sun ◽  
Ling Wang ◽  
Hao Wang ◽  
Ziqiang He ◽  
Laihao Yang ◽  
...  
Keyword(s):  
High Temperature ◽  
Molecular Dynamic ◽  
High Performance ◽  
Md Simulation ◽  
Carbonization Process ◽  
Atomic Mechanism ◽  
Initial Stage ◽  
Simulation Based ◽  
Different Temperatures ◽  
Higher Temperature

In the present work, initial stage carbonization of γ-Fe(100) surface in C2H2 from 1000 K to 1600 K has been investigated by a molecular dynamic (MD) simulation, based on which the atomic mechanism of initial stage carbonization was provided. The absorption of C and H atoms during the carbonization process under different temperatures was analyzed. The related distributions of C and H atoms in carbonized layer were provided. The results manifested that higher temperature enhanced the inward diffusion of C and H, meanwhile caused the desorption of H atom. Furthermore, the effect of preset polycrystal γ-Fe on the carbonization process has been discussed, indicating a promoting role to the absorption and inner diffusion of C and H atom. The results of this study may support the optimal design of high-performance steel to some extent.

Design and experimental tests of an active cooling system for a kind of in-vessel inspection manipulator

2020 ◽  
Vol 47 (5) ◽  
pp. 737-745
Author(s):  
Liang Du ◽  
Wei-Jun Zhang ◽  
Jian-Jun Yuan
Keyword(s):  
High Temperature ◽  
System Performance ◽  
Cooling System ◽  
Experimental Tests ◽  
Full Scale ◽  
Content Type ◽  
Temperature Environment ◽  
First Time ◽  
Inspection Task ◽  
High Temperature Environment

Purpose This paper aims to present the design and experimental tests of an active circulating cooling system for the Experimental Advanced Superconducting Tokamak in-vessel inspection manipulator, which will help the current manipulator prototype to achieve a full-scale in-vessel high temperature environment compatibility. Design/methodology/approach The high-temperature effects and heat transfer conditions of the manipulator under in-vessel environment were analyzed. An active circulating cooling system was designed and implemented on the manipulator prototype. A simulative in-vessel inspection task in a high temperature environment of 100°C was carried out to evaluate the performance of the active circulating cooling system. Findings The proposed active circulating cooling system was proved effective in helping the manipulator prototype to achieve its basic in-vessel inspection capability in a high temperature environment. The active circulating cooling system performance can be further improved considering the cooling structure coefficient differences in different manipulator parts. Originality/value For the first time, the active circulating cooling system was implemented and tested on a full-scale of the in-vessel inspection manipulator. The experimental data of the temperature distribution inside the manipulator and the operating status of the circulating system were helpful to evaluate the current active circulating cooling system design and provided effective guidance for improving the overall system performance.

Investigation on Toughness of Fibre Cocktail Reinforced Self Consolidating Concrete after High Temperature

2010 ◽  
Vol 650 ◽  
pp. 67-77
Author(s):  
Yi Ning Ding ◽  
Yue Hua Wang ◽  
Yu Lin Zhang
Keyword(s):  
High Temperature ◽  
High Performance ◽  
Steel Fibers ◽  
Failure Pattern ◽  
Self Consolidating Concrete ◽  
Pull Out ◽  
Hybrid Fibre ◽  
Before And After ◽  
Higher Temperature ◽  
Lower Temperature

The effect of different fibres on the residual load-bearing capacity and the failure pattern of high-performance self consolidating concrete (HPSCC) after exposure to high temperature hass been studied in this work. The polypropylene fibers mitigate the spalling of HPSCC element clearly, but did not show clear effect on the mechanic properties of concrete. The macro steel fiber reinforced HPSCC showed higher flexural toughness and ultimate load before and after high temperatures. The mechanical properties of hybrid fibre reinforced HPSCC (HFHPSCC) after heating were better than that of mono-fibre reinforced HPSCC. The failure mode changed from pull-out of steel fibers at lower temperature to broken down of steel fibers at higher temperature. The use of hybrid fibre can be effective in providing the residual strength and failure pattern, and improving the toughness of HPSCC after high temperature.

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