scholarly journals Novel Method for NTC Thermistor Production by Aerosol Co-Deposition and Combined Sintering

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1632 ◽  
Author(s):  
Michaela Schubert ◽  
Christian Münch ◽  
Sophie Schuurman ◽  
Véronique Poulain ◽  
Jaroslaw Kita ◽  
...  
Keyword(s):  
Energy Demand ◽  
Single Phase ◽  
Mechanical Stability ◽  
Temperature Treatment ◽  
Specific Resistivity ◽  
Electrode Structure ◽  
High Reproducibility ◽  
Ntc Thermistor ◽  
Stage Process ◽  
Novel Method

A novel three-stage process to produce NTCR sensors is presented. In this process, an uncalcined powder mixture of NiO and Mn2O3 was deposited onto an alumina substrate via aerosol co-deposition (AcD). Then, an electrode structure was screen-printed onto the surface and the composite film was sintered in a multifunctional temperature treatment. Thereby, the sintering of the electrode, the formation of the NiMn2O4 spinel and the removal of film strains took place simultaneously. This enabled a significant reduction in energy demand and workload. The manufactured sensors, both as first prototypes, as well as miniaturized chip components, were characterized by a single-phase cubic NiMn2O4 spinel structure, mechanical stability and electrical properties that were similar to those of classical NiMn2O4 bulk ceramics or tempered aerosol deposited (AD) NiMn2O4 films. Particularly noteworthy was the high reproducibility and low variation of the NTCR parameters, such as the specific resistivity at 25 °C ρ25, the electrical resistance at 25 °C R25 and the thermistor constant B. The NTCR parameters were as aging-stable as for NiMn2O4 bulk ceramics or tempered NiMn2O4 AD-films and could even be further improved by thermal post-treatment.

In-line single-phase extraction for direct determination of total iron in oils using CdTe quantum dots and a flow-batch system

2015 ◽  
Vol 7 (18) ◽  
pp. 7707-7714 ◽  
Author(s):  
Marcelo B. Lima ◽  
Stéfani Iury E. Andrade ◽  
Inakã S. Barreto ◽  
Mário César U. Araújo
Keyword(s):  
Quantum Dots ◽  
Single Phase ◽  
Direct Determination ◽  
Total Iron ◽  
Cdte Quantum Dots ◽  
Phase Extraction ◽  
Batch System ◽  
System P ◽  
Novel Method

In this work, a novel method for direct determination of total iron in viscous samples is presented.

A Novel Method of Fault Location for Single-Phase Microgrids

2015 ◽  
pp. 1-11 ◽  
Author(s):  
Jiajun Duan ◽  
Kaifeng Zhang ◽  
Liang Cheng
Keyword(s):  
Fault Location ◽  
Single Phase ◽  
Novel Method

Direct Preparation of Ce0.8Sm0.2O1.9 Powders Oxidized With H2O2 for Low Temperature SOFCs Application

2005 ◽  
Author(s):  
Jianbing Huang ◽  
Zongqiang Mao ◽  
Bin Zhu ◽  
Lizhai Yang ◽  
Ranran Peng ◽  
...  
Keyword(s):  
Single Phase ◽  
Fluorite Structure ◽  
X Ray Diffraction ◽  
Composite Electrolyte ◽  
Xrd Pattern ◽  
Transmission Electron ◽  
Direct Preparation ◽  
Novel Method ◽  
Power Densities

A novel method was developed to prepare fine doped ceria (DCO) powders directly. Ceria doped with 20 mol. % of samarium (Ce0.8Sm0.2O1.9, SDC) was prepared by in-situ oxidization of hydroxide precipitates with H2O2 in the solutions. The resultant powder desiccated at 85°C overnight was characterized by X-ray diffraction (XRD), thermogravimetry /differential thermal analysis (TG/DTA), and transmission electron microscopy (TEM). The XRD pattern showed that the as-dried SDC powder is single phase with a cubic fluorite structure like that of pure CeO2. An anode-supported SOFC was also fabricated based on SDC and 20wt. % (62mol. %Li2CO3–38 mol. %K2CO3) composite electrolyte, LiNiO2 as cathode and NiO as anode, by cold pressing. Using hydrogen as the fuel and air as the oxidant, the I-V and I-P characteristics exhibit excellent performances and the maximum power densities are about 696, 469, 377 and 240 mWcm−2 at 650, 600, 550 and 500°C, respectively.

Effect of Nb2O5 Addition to the Electrical Properties of Fe2TiO5 Ceramics-Based NTC Thermistor

2015 ◽  
Vol 827 ◽  
pp. 262-265 ◽  
Author(s):  
Wiendartun ◽  
Risdiana ◽  
Fitrilawati ◽  
Rustam E. Siregar
Keyword(s):  
Activation Energy ◽  
Grain Size ◽  
Electrical Properties ◽  
Electrical Resistance ◽  
Single Phase ◽  
Mixed Powder ◽  
Ntc Thermistor ◽  
Constant Activation Energy

The aims of this research is to identify the effect of Nb2O5addition on the electrical properties of Fe2TiO5ceramics-based NTC thermistor.The concentration of Fe2O3and TiO2was proportional to Fe2TiO5, whereas the concentration value of Nb2O5were 0, 0.5 and 1.0 mole %, respectively. Within two hours, the mixed powder was pressed at 4 ton/cm2to form pellets and sintered at 1300 °C in air. It can perceived from the XRD data that the sintered ceramics had single phase of Fe2TiO5, pseudobrookite. From SEM data, it is found that addition of Nb2O5decreases the grain size. The addition of Nb2O5increases thermistor constant, activation energy and electrical resistance of Fe2TiO5ceramics. The values of thermistor constant of Nb2O5added-Fe2TiO5ceramics were relatively large, indicated that the ceramics were aplicable as the NTC thermistor.

Novel method to synthesis of single phase zirconolite ceramic

2014 ◽  
Vol 114 (3) ◽  
pp. 188-190 ◽  
Author(s):  
S. Wang ◽  
Z. Song ◽  
Y. Teng ◽  
L. Wang
Keyword(s):  
Single Phase ◽  
Novel Method

scholarly journals Noise Reduction Design with Trapezoidal Back-EMF and Asymmetric Air-Gap for Single-Phase BLDC Refrigerator Cooling Fan Motor

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5467
Author(s):  
Jin-Hwan Lee ◽  
Sang-Yong Jung
Keyword(s):  
Single Phase ◽  
Three Dimensional ◽  
Torque Ripple ◽  
Air Gap ◽  
Manufacturing Cost ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Novel Method ◽  
The Dead ◽  
Three Dimensional Finite Element

In this study, a novel method for reducing the noise generated by single-phase claw-pole motors employed as refrigerator fan blowers is proposed. A single-phase claw-pole motor has the advantages of low manufacturing cost, easy manufacturing, and a high number of turns. However, in such motors, current delays occur owing to a high inductance; therefore, it is necessary to merge the back-electromotive force and current phases into the same phase using the phase advance method. Additionally, a single-phase motor exhibits dead torque and zero torque at an electrical angle of 180° owing to its electrical characteristics, and the dead torque deteriorates the average torque and torque ripple characteristics of the motor. In this study, a novel method is proposed to make the air gap asymmetrical by tilting the claw to reduce the noise generated by single-phase claw-pole motors. An asymmetric air gap allows the cogging torque to eliminate the dead torque caused by alignment torques, causing the torque ripple to decrease. To validate the effectiveness of the proposed method, the proposed model is compared with a base model via three-dimensional finite element analysis. Furthermore, the two models are manufactured and a noise test is conducted in an anechoic chamber to compare the noise difference between the two models.

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