Advanced sodium storage property in an exfoliated MoO3 anode: the stability and performance improvement by in situ impedance mapping

2017 ◽  
Vol 5 (38) ◽  
pp. 20491-20496 ◽  
Author(s):  
Amlan Roy ◽  
Prasit Kumar Dutta ◽  
Sagar Mitra
Keyword(s):  
Performance Improvement ◽  
High Capacity ◽  
Stepwise Manner ◽  
And Performance ◽  
The Stability ◽  
Sodium Storage ◽  
Storage Property

A two-step modification to morphology in conjunction with in situ PEIS mapping are employed to achieve high capacity and improved retention in a stepwise manner.

Map Width Enhancement Technique for a Turbocharger Compressor

2013 ◽  
Vol 136 (6) ◽  
Author(s):  
Subenuka Sivagnanasundaram ◽  
Stephen Spence ◽  
Juliana Early
Keyword(s):  
Performance Improvement ◽  
Peak Pressure ◽  
Pressure Ratio ◽  
Comparison Study ◽  
Heavy Duty ◽  
Recirculating Flow ◽  
Heavy Duty Diesel ◽  
And Performance ◽  
The Stability ◽  
The Impact

This paper presents an investigation of map width enhancement and the performance improvement of a turbocharger compressor using a series of static vanes in the annular cavity of a classical bleed slot system. The investigation has been carried out using both experimental and numerical analysis. The compressor stage used for this study is from a turbocharger unit used in heavy duty diesel engines of approximately 300 kW. Two types of vanes were designed and added to the annular cavity of the baseline classical bleed slot system. The purpose of the annular cavity vane technique is to remove some of the swirl that can be carried through the bleed slot system, which would influence the pressure ratio. In addition to this, the series of cavity vanes provides a better guidance to the slot recirculating flow before it mixes with the impeller main inlet flow. Better guidance of the flow improves the mixing at the inducer inlet in the circumferential direction. As a consequence, the stability of the compressor is improved at lower flow rates and a wider map can be achieved. The impact of two cavity vane designs on the map width and performance of the compressor was highlighted through a detailed analysis of the impeller flow field. The numerical and experimental study revealed that an effective vane design can improve the map width and pressure ratio characteristic without an efficiency penalty compared to the classical bleed slot system without vanes. The comparison study between the cavity vane and noncavity vane configurations presented in this paper showed that the map width was improved by 14.3% due to a significant reduction in surge flow and the peak pressure ratio was improved by 2.25% with the addition of a series of cavity vanes in the annular cavity of the bleed slot system.

Map Width Enhancement Technique for a Turbocharger Compressor

2012 ◽  
Author(s):  
Subenuka Sivagnanasundaram ◽  
Stephen Spence ◽  
Juliana Early
Keyword(s):  
Performance Improvement ◽  
Peak Pressure ◽  
Pressure Ratio ◽  
Comparison Study ◽  
Heavy Duty ◽  
Recirculating Flow ◽  
Heavy Duty Diesel ◽  
And Performance ◽  
The Stability ◽  
The Impact

This paper presents an investigation of map width enhancement and the performance improvement of a turbocharger compressor using a series of static vanes in the annular cavity of a classical bleed slot system. The investigation has been carried out using both experimental and numerical analysis. The compressor stage used for this study is from a turbocharger unit used in heavy duty diesel engines of approximately 300 kW. Two types of vanes have been designed and added to the annular cavity of the baseline classical bleed slot system. The purpose of the annular cavity vane technique is to remove some of the swirl that can be carried through the bleed slot system, which would influence the pressure ratio. In addition to this, the series of cavity vanes provides a better guidance to the slot recirculating flow before it mixes with the impeller main inlet flow. Better guidance of the flow improves the mixing at the inducer inlet in the circumferential direction. As a consequence, the stability of the compressor is improved at lower flow rates and a wider map can be achieved. The impact of two cavity vane designs on the map width and performance of the compressor has been highlighted through a detailed analysis of the impeller flow field. The numerical and experimental study revealed that an effective vane design can improve the map width and pressure ratio characteristic without an efficiency penalty compared to the classical bleed slot system without vanes. The comparison study between the cavity vane and non-cavity vane configurations presented in this paper showed that the map width was improved by 14.3% due to a significant reduction in surge flow and the peak pressure ratio was improved by 2.25% with the addition of a series of cavity vanes in the annular cavity of the bleed slot system.

scholarly journals Understanding Phase Stability of Metallic 1T-MoS2 Anodes for Sodium-Ion Batteries

2019 ◽  
Vol 4 (2) ◽  
pp. 53 ◽  
Author(s):  
Christopher Lane ◽  
Daxian Cao ◽  
Hongyan Li ◽  
Yucong Jiao ◽  
Bernardo Barbiellini ◽  
...  
Keyword(s):  
Phase Stability ◽  
First Principles ◽  
High Capacity ◽  
Sodium Ion ◽  
Sodium Ion Batteries ◽  
In Situ Raman ◽  
Charging And Discharging Processes ◽  
The Stability ◽  
Insight Into

We discuss metallic 1T-MoS2 as an anode material for sodium-ion batteries (SIBs). In situ Raman is used to investigate the stability of metallic MoS2 during the charging and discharging processes. Parallel first-principles computations are used to gain insight into the experimental observations, including the measured conductivities and the high capacity of the anode.

scholarly journals Measuring Structural Heterogeneities in Metallic Glasses Using Transmission Electron Microscopy

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1085 ◽  
Author(s):  
Lin Tian ◽  
Cynthia A. Volkert
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Metallic Glasses ◽  
Local Density ◽  
Temporal Correlations ◽  
Transmission Electron ◽  
Excellent Spatial Resolution ◽  
And Performance ◽  
The Stability

Local heterogeneities in the structure and properties of metallic glasses have recently been predicted by computer simulations and also observed in experiments. These heterogeneities are important in understanding the stability and performance of metallic glasses. Progress has been made in measuring heterogeneities in elastic properties and local density down to length scales of less than 10 nm. In this review, we focus on studies of structural and mechanical heterogeneities with emphasis on those achieved by transmission electron microscopy which has an excellent spatial resolution, multifunctional detection modes, as well as in-situ testing capabilities. We argue that the next important step in understanding the behavior of metallic glasses lies in understanding the spatial and temporal correlations between the various structural and mechanical heterogeneities.

scholarly journals A State of Art Survey for OS Performance Improvement

2018 ◽  
Vol 6 (3) ◽  
pp. 118-123 ◽  
Author(s):  
Lailan M. Haji ◽  
Subhi R.M. Zeebaree ◽  
Karwan Jacksi ◽  
Diyar Q. Zeebaree
Keyword(s):  
Performance Improvement ◽  
Critical Issue ◽  
The Past ◽  
Performance Requirements ◽  
And Performance ◽  
Measurement And Evaluation ◽  
The Stability ◽  
High Level ◽  
Multiple Metrics ◽  
Selection Of

Through the huge growth of heavy computing applications which require a high level of performance, it is observed that the interest of monitoring operating system performance has also demanded to be grown widely. In the past several years since OS performance has become a critical issue, many research studies have been produced to investigate and evaluate the stability status of OSs performance. This paper presents a survey of the most important and state of the art approaches and models to be used for performance measurement and evaluation. Furthermore, the research marks the capabilities of the performance-improvement of different operating systems using multiple metrics. The selection of metrics which will be used for monitoring the performance depends on monitoring goals and performance requirements. Many previous works related to this subject have been addressed, explained in details, and compared to highlight the top important features that will very beneficial to be depended for the best approach selection.

On Robust Stability and Performance With Time-Varying Control

1995 ◽  
Vol 117 (4) ◽  
pp. 635-637 ◽  
Author(s):  
Mohammed Dahleh
Keyword(s):  
Performance Improvement ◽  
Robust Stabilization ◽  
Point Of View ◽  
Time Varying ◽  
Discrete Time Systems ◽  
And Performance ◽  
The Stability ◽  
Bounded Perturbations ◽  
Time Invariant ◽  
Time Systems

The analysis of time-varying control for robust stabilization and performance improvement is considered. This problem has been investigated in recent years from the point of view of assessing the capabilities of time-varying control to stabilize plants with structured norm bounded perturbations. In this paper, it is shown that time-varying compensation provides no improvement over time-invariant compensation for the stability and performance robustness of discrete-time systems with structured, causal, time-varying, and norm-bounded perturbations, where the norm on the perturbations is the l2-induced norm. The results of this paper help in completing the picture for the case of time-varying perturbations.

Influence of ion-milling on the T2 phase in Al-2.5%Li-2.5%Cu alloy

1989 ◽  
Vol 47 ◽  
pp. 288-289
Author(s):  
J. R. Reed ◽  
D. J. Michel ◽  
P. R. Howell
Keyword(s):  
Thin Foil ◽  
Icosahedral Symmetry ◽  
Ion Milling ◽  
Cu Alloy ◽  
Thin Foils ◽  
Heat Treated ◽  
Aluminum Solid Solution ◽  
In Situ Heating ◽  
The Stability

The Al6Li3Cu (T2) phase, which exhibits five-fold or icosahedral symmetry, forms through solid state precipitation in dilute Al-Li-Cu alloys. Recent studies have reported that the T2 phase transforms either during TEM examination of thin foils or following ion-milling of thin foil specimens. Related studies have shown that T2 phase transforms to a microcrystalline array of the TB phase and a dilute aluminum solid solution during in-situ heating in the TEM. The purpose of this paper is to report results from an investigation of the influence of ion-milling on the stability of the T2 phase in dilute Al-Li-Cu alloy.The 3-mm diameter TEM disc specimens were prepared from a specially melted Al-2.5%Li-2.5%Cu alloy produced by conventional procedures. The TEM specimens were solution heat treated 1 h at 550°C and aged 1000 h at 190°C in air to develop the microstructure. The disc specimens were electropolished to achieve electron transparency using a 20:80 (vol. percent) nitric acid: methanol solution at -60°C.

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