A complete, and somewhat revolutionary, system design approach is needed to exploit the benefits that a more-electric aircraft can provide. Traditional-mounted auxiliary drives, bleed air extraction will disappear, be replaced with integral engine starter/generators electrically driven actuators pumps. five-phase Power Management Distribution System for More-Electric Aircraft (MADMEL) program was awarded by Air Force Northrop/Grumman Military Division in September 1991. The objective of...

To fulfill the future NOx emission regulations, use of exhaust gas recirculation could be necessary for engine starting at cold conditions. In this context, condensation inside line appear, affecting in several ways components and their life span. article, a mathematical model is developed with aim predicting conditions that produce phenomenon to appear circuits an internal combustion working low ambient temperatures (−7 °C). particular, humidity ratio characterize appearance are estimated...

A five-phase Power Management and Distribution System for a More-Electric Aircraft (MADMEL) program was awarded by the Air Force to Northrop/Grumman Military Division in September 1991. The objective of is design, develop, demonstrate an advanced electrical power generation distribution system (MEA). MEA emphasizes use place hydraulics, pneumatic, mechanical optimize performance life cycle cost aircraft. This paper presents overview MADMEL top-level summary results, development test major...

A DC-DC converter and a DC-AC inverter are under development for More Electric Aircraft (MEA) use. They both highly compact designed to operate from 270 Vdc input power produce output that meets requirements fighter aircraft, including compliance with MIL-STD-704E MIL-STD-461D guidelines. Both units be cooled Poly Alpha Olefin (PAO) at 30/spl deg/C maximum inlet temperature least 30 s after loss of coolant flow before shutting down. withstand 20 Gs shock loadings random vibration up 0.04...

The low efficiency of the after-treatment systems during cold start period internal combustion engines leads to excessive pollutant emissions levels. To reduce nitrogen oxide at these conditions, it could be necessary use high- and low-pressure exhaust gas recirculation strategies, even operating temperatures. This article evaluates impact using a cooler bypass in Euro 6 turbocharged diesel engine running under conditions (–7 °C). A new compact line fitted with system for is used aim...

Internal combustion engines working at cold conditions lead to the production of excessive pollutant emissions levels. The use exhaust gas recirculation could be necessary reduce nitrogen oxides emissions, even these conditions. This paper evaluates impact using high-pressure strategy while diesel particulate filter is under active regeneration mode on a Euro 6 turbocharged engine running low ambient temperature (−7°C). evaluated 40 h operation, 20 them two systems in combination. results...

A 400 Hz aircraft power generating system which has been designed to achieve significant improvements in density and reliability is introduced. Design targets for this exploratory development program include (generator-plus-converter) of 1 kVA/lb mean-time-between-failure (MTBF) 500 h. At the heart new variable-speed constant-frequency (VSCF) configuration a high-frequency resonant link inverter so that all switching occurs under zero-voltage conditions. Advantages minimization losses...

We use the relations between braid and mapping class groups of a compact, connected, non-orientable surface N without boundary those its orientable double covering S to study embeddings these their (virtual) cohomological dimensions. first generalise results [4, 14] show that group MCG(N;k) relative k-point subset embeds in MCG(S;2k) 2k-point subset. then compute dimension all connected aspherical surfaces boundary, generalising [15]. Finally, if genus is at least 2, we deduce upper bounds...

The ability to detect and quantify the state of charge (SoC) lithium-ion (Li-ion) batteries - most common energy sources for portable devices using fast nondestructive evaluation techniques is crucial technology. Ten factory-new 18650 were imaged at 100% 0% SoC a Vantage-256 system (Verasonics, Inc.) equipped with 5-MHz 64-element ultrasound array (Imasonic SAS). Quantitative spectroscopy (QUS) parameters, i.e., midbandfit (MBf), spectral slope (SS), intercept (I0), obtained from normalized...

In this work we developed a methodology to manufacture new type of arterial model that could be used in experimental setting instead excised arteries while developing imaging modalities. CT-images the descending aorta were create molds with patient specific morphology. A polyvinyl alcohol (PVA) solution reinforcing cotton mesh was generate models. The is circumferentially elastic non-compliant longitudinally and responsible for non-linear anisotropic mechanical behavior Two models fabricated...

Monitoring lithium-ion batteries (LIBs) degradation is essential for decarbonizing electricity generation and transportation.Key metrics include State of Charge (SOC) Health (SOH).SOC measures the charge level, while SOH represents usable capacity.SOH crucial in determining end-of-life.Even at 70-80% SOH, LIBs can still store energy, finding value as secondlife (SLBs).However, conventional estimation methods SOC/SOH are timeconsuming.Recent research suggests that affects ultrasonic wave...

The aftertreatment systems used in internal combustion engines need high temperatures for reaching its maximum efficiency. By this reason, during the engine cold start period or restart operation, excessive pollutant emissions levels are emitted to atmosphere. This paper evaluates impact of using a new cylinder deactivation strategy on Euro 6 turbocharged diesel running under conditions (−7°C) with aim improving warm-up process. is evaluated two parts. First, an experimental study performed...

This paper is a survey of the relationship between labelled configuration spaces, mapping class groups with marked points and function spaces. In particular, we collect calculations cohomology for low-genus orientable non-orientable surfaces.

Arterial elasticity has become a topic of importance in the past decades, as it shown that can be used to predict cardiovascular diseases and mortality. Several vivo ex techniques have been developed characterize mechanical properties vessels. In tend ignore anisotropicity vessel wall components. While destructive do not account for geometry arteries. this paper we present technique using sonometry study soft tubes excised pig carotids different directions. The method uses piezoelectric...

The mapping class group $\Gamma^k(N_g)$ of a non-orientable surface with punctures is studied via classical homotopy theory configuration spaces. In particular, we obtain version the Birman exact sequence. case $\mathbb R {\rm P}^2$, analize Serre spectral sequence fiber bundle $F_k(\mathbb P}^2)/\Sigma_k \to X_k BSO(3)$ where $X_k$ $K(\Gamma^k(\mathbb P}^2),1)$ and P}^2)/\Sigma_k$ denotes space unordered $k$-tuples distinct points in P}^2$. As consequence, express mod-2 cohomology...

Abstract The mapping class group $\Gamma ^k(N_g)$ of a non-orientable surface with punctures is studied via classical homotopy theory configuration spaces. In particular, we obtain version the Birman exact sequence. case ${\mathbb{R}} \textrm{P}^2$, analyze Serre spectral sequence fiber bundle $F_k({\mathbb{R}}{\textrm{P}}^{2}) / \Sigma _k \to X_k BSO(3)$ where $X_k$ $K(\Gamma ^k({\mathbb{R}} \textrm{P}^2),1)$ and _k$ denotes space unordered $k$-tuples distinct points in \textrm{P}^2$. As...