A Power Dense Planetary Drive for Rotorcraft Applications

2013 ◽  
Author(s):  
Xiaolan Ai ◽  
Curtis Orkin ◽  
Randy Kruse
Keyword(s):  
Power Density ◽  
High Performance ◽  
Power Flow ◽  
Load Sharing ◽  
Advanced Materials ◽  
The Novel ◽  
Powertrain System ◽  
Planet Gear ◽  
Primary Focus ◽  
Rotary Wing

Increasing power density is an on-going objective for engineers of fixed wing and rotary wing aircraft. The powertrain system is one of the largest contributors to the total mass of the aircraft and the geartrain is the largest contributor to the mass of the powertrain system. As such, the geartrain becomes the primary focus of many power density studies and is the focus of this paper. Epicyclic geartrains are known to provide high power density and have become the geartrain of choice for the main power flow in virtually all aircraft designs. This paper presents a unique compound planetary design targeting a helicopter main gearbox transmission application. The design significantly improves power density through its innovative planet gear load-sharing configuration along with the utilization of high-performance materials for gears and bearings. Design studies were conducted comparing the power density of this new design to a baseline gearbox design. The results of these studies demonstrate an estimated 38% power density improvement over the baseline configuration. Of the total improvement, 86% is attributed to the novel load-sharing configuration while 14% is attributed to utilization of advanced materials and processes.

A High Ratio Power Dense Planetary Drive for Rotorcraft Applications

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Xiaolan Ai ◽  
Curtis Orkin ◽  
Randy Kruse
Keyword(s):  
Power Density ◽  
High Performance ◽  
Power Flow ◽  
Load Sharing ◽  
High Ratio ◽  
Advanced Materials ◽  
The Novel ◽  
Design Studies ◽  
Planet Gear ◽  
Unique Compound

Epicyclic geartrains are known to provide high power density and have become the geartrain of choice for the main power flow in virtually all rotorcraft designs. This paper presents a unique compound planetary design targeting a helicopter main gearbox transmission application. The design significantly improves power density over conventional geartrains through its innovative planet gear load-sharing configuration along with the utilization of high-performance materials for gears and bearings. Design studies were conducted comparing the power density of this new design to a baseline gearbox design. The results of these studies demonstrate an estimated 38% power density improvement over the baseline configuration. Of the total improvement, 86% is attributed to the novel load-sharing configuration while 14% is attributed to utilization of advanced materials and processes.

scholarly journals Design and Regulation of Novel MnFe2O4@C Nanowires as High Performance Electrode for Supercapacitor

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 777 ◽  
Author(s):  
Lei Geng ◽  
Fengfeng Yan ◽  
Chenhao Dong ◽  
Cuihua An
Keyword(s):  
Energy Density ◽  
Electric Conductivity ◽  
Power Density ◽  
High Performance ◽  
High Specific Capacitance ◽  
The Novel ◽  
Micro Emulsion ◽  
High Electric Conductivity

Bimetallic oxides have been considered as potential candidates for supercapacitors due to their relatively high electric conductivity, abundant redox reactions and cheapness. However, nanoparticle aggregation and huge volume variation during charging-discharging procedures make it hard for them to be applied widely. In this work, one-dimensional (1D) MnFe2O4@C nanowires were in-situ synthesized via a simply modified micro-emulsion technique, followed by thermal treatment. The novel 1D and core-shell architecture, and in-situ carbon coating promote its electric conductivity and porous feature. Due to these advantages, the MnFe2O4@C electrode exhibits a high specific capacitance of 824 F·g−1 at 0.1 A·g−1 and remains 476 F·g−1 at 5 A·g−1. After 10,000 cycles, the capacitance retention of the MnFe2O4@C electrode is up to 93.9%, suggesting its excellent long-term cycling stability. After assembling with activated carbon (AC) to form a MnFe2O4@C//AC device, the energy density of this MnFe2O4@C//AC device is 27 W·h·kg−1 at a power density of 290 W·kg−1, and remains at a 10 W·h·kg−1 energy density at a high power density of 9300 W·kg−1.

Novel Catalytic Electrodes for High Performance Solid Oxide Fuel Cells Operated at Intermediate Temperatures

2007 ◽  
Vol 336-338 ◽  
pp. 428-433 ◽  
Author(s):  
Bin Zhu ◽  
Xiang Rong Liu ◽  
Ye Cheng ◽  
Mi Lin Zhang
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Power Density ◽  
High Performance ◽  
The Novel ◽  
Composite Electrodes ◽  
Composite Electrolytes ◽  
Coal Gas ◽  
Internal Reforming ◽  
Special Cases ◽  
Novel Catalyst

The all-ceria-composite ITSOFCs have demonstrated extraordinary fuel cell performances since the ceria-composite electrodes are very catalytic and conductive, and the ceria-composite electrolytes are highly conductive and also electrolytic, in addition to excellent compatibility between the electrolyte and electrodes based on the same ceria-based composite materials. The power density outputs from 200 to 800 mWcm-2, were obtained for temperatures between 400 and 700°C. The maximum power density 0.72 Wcm-2 (1500 mAcm-2) at 600°C and 0.82 Wcm-2 (1800 mAcm-2) at 700°C were achieved, respectively. These highly catalytic electrodes functioned extensively for many different fuels, such as hydrogen and hydrocarbon fuels, e.g., natural gas, coal gas, methanol and ethanol etc. In some special cases, the ITSOFCs with the ceria-composite electrodes could also work at as low as 200°C. All these good performances are based on the novel catalyst function of the ceria-composite electrodes and internal reforming mechanism.

scholarly journals Benefits of Higher-Temperature Operation in Boosted SI Engines Enabled by Advanced Materials

2018 ◽  
Author(s):  
Zachary G. Mills ◽  
Charles E. A. Finney ◽  
K. Dean Edwards ◽  
J. Allen Haynes
Keyword(s):  
Power Density ◽  
High Speed ◽  
High Performance ◽  
Direct Injection ◽  
Fuel Efficiency ◽  
Advanced Materials ◽  
Valuable Insight ◽  
Light Duty ◽  
Selective Cooling ◽  
Si Engines

To meet the demand for greater fuel efficiency in passenger vehicles, various strategies are employed to increase the power density of light-duty SI engines, with attendant thermal or system efficiency increases. One approach is to incorporate higher-performance alloys for critical engine components. These alloys can have advantageous thermal or mechanical properties at higher temperatures, allowing for components constructed from these materials to meet more severe pressure and temperature demands, while maintaining durability. Advanced alloys could reduce the need for charge enrichment to protect certain gas-path components at high speed and load conditions, permit more selective cooling to reduce heat-transfer losses, and allow engine downsizing, while maintaining performance, by achieving higher cylinder temperatures and pressures. As a first step in investigating downsizing strategies made possible through high-performance alloys, a GT-Power model of a 4-cylinder 1.6L turbocharged direct-injection SI engine was developed. The model was tuned and validated against experimental dynamometer data collected from a corresponding engine. The model was then used to investigate various operating strategies for increasing power density. Results from these investigations will provide valuable insight into how new materials might be utilized to meet the needs of future light-duty engines and will serve as the basis for a more comprehensive investigation using more-detailed thermo-mechanical modeling.

Insights into Transdermal Drug Delivery: Approaches for Redressal of a Burgeoning Issue of Osteoporosis

2020 ◽  
Vol 20 (10) ◽  
pp. 1682-1695
Author(s):  
Foziyah Zakir ◽  
Kanchan Kohli ◽  
Farhan J. Ahmad ◽  
Zeenat Iqbal ◽  
Adil Ahmad
Keyword(s):  
Drug Delivery ◽  
Transdermal Delivery ◽  
Oral Delivery ◽  
Calcium Absorption ◽  
Early Stage ◽  
Osteoporotic Fractures ◽  
The Novel ◽  
Systemic Delivery ◽  
Primary Focus ◽  
The Cost

Osteoporosis is a progressive bone disease that remains unnoticed until a fracture occurs. It is more predominant in the older age population, particularly in females due to reduced estrogen levels and ultimately limited calcium absorption. The cost burden of treating osteoporotic fractures is too high, therefore, primary focus should be treatment at an early stage. Most of the marketed drugs are available as oral delivery dosage forms. The complications, as well as patient non-compliance, limit the use of oral therapy for prolonged drug delivery. Transdermal delivery systems seem to be a promising approach for the delivery of anti-osteoporotic active moieties. One of the confronting barriers is the passage of drugs through the SC layers followed by penetration to deeper dermal layers. The review focuses on how anti-osteoporotic drugs can be molded through different approaches so that they can be exploited for the skin to systemic delivery. Insights into the various challenges in transdermal delivery and how the novel delivery system can be used to overcome these have also been detailed.

scholarly journals Pocket MUSE: an affordable, versatile and high-performance fluorescence microscope using a smartphone

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yehe Liu ◽  
Andrew M. Rollins ◽  
Richard M. Levenson ◽  
Farzad Fereidouni ◽  
Michael W. Jenkins
Keyword(s):  
High Performance ◽  
Point Of Care ◽  
Low Cost ◽  
Consumer Electronics ◽  
Practical Implementation ◽  
The Novel ◽  
Point Of Care Diagnostics ◽  
Optical Module ◽  
Optical Configuration ◽  
User Friendly

AbstractSmartphone microscopes can be useful tools for a broad range of imaging applications. This manuscript demonstrates the first practical implementation of Microscopy with Ultraviolet Surface Excitation (MUSE) in a compact smartphone microscope called Pocket MUSE, resulting in a remarkably effective design. Fabricated with parts from consumer electronics that are readily available at low cost, the small optical module attaches directly over the rear lens in a smartphone. It enables high-quality multichannel fluorescence microscopy with submicron resolution over a 10× equivalent field of view. In addition to the novel optical configuration, Pocket MUSE is compatible with a series of simple, portable, and user-friendly sample preparation strategies that can be directly implemented for various microscopy applications for point-of-care diagnostics, at-home health monitoring, plant biology, STEM education, environmental studies, etc.

scholarly journals Reliability-Oriented Design of Inverter-Fed Low-Voltage Electrical Machines: Potential Solutions

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4144
Author(s):  
Yatai Ji ◽  
Paolo Giangrande ◽  
Vincenzo Madonna ◽  
Weiduo Zhao ◽  
Michael Galea
Keyword(s):  
Power Density ◽  
High Speed ◽  
High Performance ◽  
Low Voltage ◽  
Electrical Machines ◽  
Design Stage ◽  
Switching Frequency ◽  
Special Focus ◽  
Electrical Machine ◽  
Engineering Approach

Transportation electrification has kept pushing low-voltage inverter-fed electrical machines to reach a higher power density while guaranteeing appropriate reliability levels. Methods commonly adopted to boost power density (i.e., higher current density, faster switching frequency for high speed, and higher DC link voltage) will unavoidably increase the stress to the insulation system which leads to a decrease in reliability. Thus, a trade-off is required between power density and reliability during the machine design. Currently, it is a challenging task to evaluate reliability during the design stage and the over-engineering approach is applied. To solve this problem, physics of failure (POF) is introduced and its feasibility for electrical machine (EM) design is discussed through reviewing past work on insulation investigation. Then the special focus is given to partial discharge (PD) whose occurrence means the end-of-life of low-voltage EMs. The PD-free design methodology based on understanding the physics of PD is presented to substitute the over-engineering approach. Finally, a comprehensive reliability-oriented design (ROD) approach adopting POF and PD-free design strategy is given as a potential solution for reliable and high-performance inverter-fed low-voltage EM design.

scholarly journals The acquisition and generalization of fear of touch

2020 ◽  
Vol 20 (4) ◽  
pp. 809-819 ◽  
Author(s):  
Emma E. Biggs ◽  
Ann Meulders ◽  
Amanda L. Kaas ◽  
Rainer Goebel ◽  
Johan W. S. Vlaeyen
Keyword(s):  
Chronic Pain ◽  
Stimulus Generalization ◽  
Spontaneous Pain ◽  
The Novel ◽  
Vibrotactile Stimulation ◽  
Differential Acquisition ◽  
New Locations ◽  
Conditioned Responses ◽  
Primary Focus ◽  
Post Hoc

AbstractObjectivesContemporary fear-avoidance models of chronic pain posit that fear of pain, and overgeneralization of fear to non-threatening stimuli is a potential pathway to chronic pain. While increasing experimental evidence supports this hypothesis, a comprehensive investigation requires testing in multiple modalities due to the diversity of symptomatology among individuals with chronic pain. In the present study we used an established tactile fear conditioning paradigm as an experimental model of allodynia and spontaneous pain fluctuations, to investigate whether stimulus generalization occurs resulting in fear of touch spreading to new locations.MethodsIn our paradigm, innocuous touch is presented either paired (predictable context) or unpaired (unpredictable context) with a painful electrocutaneous stimulus (pain-US). In the predictable context, vibrotactile stimulation to the index or little finger was paired with the pain-US (CS+), whilst stimulation of the other finger was never paired with pain (CS−). In the unpredictable context, vibrotactile stimulation to the index and little fingers of the opposite hand (CS1 and CS2) was unpaired with pain, but pain-USs occurred unpredictable during the intertrial interval. During the subsequent generalization phase, we tested the spreading of conditioned responses (self-reported fear of touch and pain expectancy) to the (middle and ring) fingers between the CS+ and CS−, and between the CS1 and CS2.ResultsDifferential fear acquisition was evident in the predictable context from increased self-reported pain expectancy and self-reported fear for the CS + compared to the CS−. However, expectancy and fear ratings to the novel generalization stimuli (GS+ and GS−) were comparable to the responses elicited by the CS−. Participants reported equal levels of pain expectancy and fear to the CS1 and CS2 in the unpredictable context. However, the acquired fear did not spread in this context either: participants reported less pain expectancy and fear to the GS1 and GS2 than to the CS1 and CS2. As in our previous study, we did not observe differential acquisition in the startle responses.ConclusionsWhilst our findings for the acquisition of fear of touch replicate the results from our previous study (Biggs et al., 2017), there was no evidence of fear generalization. We discuss the limitations of the present study, with a primary focus on procedural issues that were further investigated with post-hoc analyses, concluding that the present results do not show support for the hypothesis that stimulus generalization underlies spreading of fear of touch to new locations, and discuss how this may be the consequence of a context change that prevented transfer of acquisition.

scholarly journals Estimations on Properties of Redox Reactions to Electrical Energy and Storage Device of Thermoelectric Pipe (TEP) Using Polymeric Nanofluids

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1812
Author(s):  
Qin Gang ◽  
Rong-Tsu Wang ◽  
Jung-Chang Wang
Keyword(s):  
Thermal Conductivity ◽  
Power Density ◽  
Heat Dissipation ◽  
Electrical Energy ◽  
Steel Tube ◽  
Storage Device ◽  
Stainless Steel Tube ◽  
The Novel ◽  
Empirical Formulas ◽  
Dissipative Heat

A thermoelectric pipe (TEP) is constructed by tubular graphite electrodes, Teflon material, and stainless-steel tube containing polymeric nanofluids as electrolytes in this study. Heat dissipation and power generation (generating capacity) are both fulfilled with temperature difference via the thermal-electrochemistry and redox reaction effects of polymeric nanofluids. The notion of TEP is to recover the dissipative heat from the heat capacity generated by the relevant machine systems. The thermal conductivity and power density empirical formulas of the novel TEP were derived through the intelligent dimensional analysis with thermoelectric experiments and evaluated at temperatures between 25 and 100 °C and vacuum pressures between 400 and 760 torr. The results revealed that the polymeric nanofluids composed of titanium dioxide (TiO2) nanoparticles with 0.2 wt.% sodium hydroxide (NaOH) of the novel TEP have the best thermoelectric performance among these electrolytes, including TiO2 nanofluid, TiO2 nanofluid with 0.2 wt.% NaOH, deionized water, and seawater. Furthermore, the thermal conductivity and power density of the novel TEP are 203.1 W/(m·K) and 21.16 W/m3, respectively.

High-performance Pd nanocatalysts based on the novel N-doped Ti3C2 support for ethanol electrooxidation in alkaline media

2021 ◽  
pp. 138902
Author(s):  
Zhangxin Chen ◽  
Binbin Yu ◽  
Jiajie Cao ◽  
Xiuli Wen ◽  
Minghui Luo ◽  
...  
Keyword(s):  
High Performance ◽  
Alkaline Media ◽  
The Novel ◽  
Ethanol Electrooxidation
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