This paper presents the findings of a study conducted tn 2010 by NASA Innovation Fund Award project entitled Elastically Shaped Future Air Vehicle Concept. The three themes in support meeting national and global aviation challenges reducing fuel burn for present future systems. first theme addresses drag reduction goal through innovative vehicle configurations via non-planar wing optimization. Two candidate concepts have been identified from optimization: drooped shape an inflected shape. is...

Since 1990 the Hanoi capital region (or metropolitan area) in Vietnam has undergone rapid development, which gone together with increasing socio-economic growth and prosperity. However, environmental degradation that accompanied urban development raised considerable concern from public recent years. This research investigates effects of on sprawl, heat island (UHI), weather phenomena are related to quality life period 1999–2016. To achieve these objectives, remote sensing technologies were...

This study investigated the leaching resistance of alkali activated slag mortars (AAS) under immersion in a 6 M NH4NO3 solution for duration up to 28 days, taking into consideration effect water-to-binder (w/b) ratio. SEM-EDS analysis revealed decalcification, desodiumization, and dealumination AASs during leaching, leading changes microstructure micro-mechanical properties materials. A combination N2-adsorption MIP demonstrated that there was coarsening structure an increase porosity along...

Carbonation of alkali activated materials is one the main deteriorations affecting their durability. However, current understanding structural alteration these exposed to an environment inducing carbonation at nano/micro scale remains limited. This study examined evolution phase assemblages slag mortars subjected accelerated (1% CO2, 60% relative humidity, up 28 day carbonation) using XRD, FTIR and 29Si, 27Al, 23Na MAS NMR. Samples with three water binder (w/b) ratios (0.35, 0.45, 0.55) were...

Geopolymers and other alkali-activated materials were investigated in detail as alternatives to ordinary Portland cement because of their reduced CO2 emissions, high (radionuclide) binding capacities, low permeabilities. The last two properties make them potential for the immobilization several types chemical waste. In this context, direct liquid waste streams would be a useful application. This study aimed develop geopolymers with water-to-binder ratios, but good mechanical strengths, while...

In this study, we investigated the improvement of thermal and mechanical properties Vietnam deproteinized natural rubber (DPNR) via graft copolymerization methyl methacrylate (MMA). The was achieved successfully in latex stage using tert-butyl hydroperoxide (TBHPO) tetra-ethylenepentamine (TEPA) as radical initiators at 30°C. By grafting with various MMA feeds initiator concentration <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"...

Presented here is the evaluation of multiple adaptive control technologies for a generic transport aircraft simulation. For this study, seven model reference (MRAC) based were considered. Each technology was integrated into an identical dynamic-inversion architecture and tuned using methodology on metrics specific design requirements. Simulation tests then performed to evaluate each s sensitivity time-delay, flight condition, uncertainty, artificially induced cross-coupling. The resulting...

Presented herein are the results of an adaptive control simulation study using metrics and pilot handling qualities on a generic commercial aviation aircraft. For this study, seven model reference (MRAC) technologies were identified for investigation. Each technology was tuned consistent methodology based specific design requirements. Additionally, each integrated with preexisting dynamic-inversion baseline architecture. Scenarios evaluation then designed Cooper-Harper criteria. This paper...

This paper presents a new adaptive control approach using Chebyshev orthogonal polynomials as basis functions in least-squares functional approximation. The use of improves the function approximation significantly and enables better convergence parameter estimates. Flight simulations demonstrate effectiveness proposed approach.

In this study, we investigated the improvement of thermal properties Vietnam deproteinized natural rubber (DPNR) via graft copolymerization styrene/acrylonitrile and transfer hydrogenation. The was achieved successfully in latex stage using tert ‐butyl hydroperoxide tetraethylenepentamine as radical initiators at 30°C. obtained copolymer hydrogenated by a diimide reduction system presence different copper (II) homogeneous catalysts. effects styrene to acrylonitrile on total conversion...

An elastic aircraft model is developed for a generic general aviation using finite element and an aerodynamic strip method. The longitudinal adaptive controller designed reference control scheme, modified to use “E-Z fly” decoupled architecture, which tracks vertical flight path angle true airspeed. signal computed weighted least mean square optimization, gives the designer more influence on behavior of adaptation. A notch filter decouple adaptation from structural modes. proposed tuned...

With the evolution of Internet and smartphone devices, advertising has become one most important methods for delivering promotional marketing messages to customers. However, efficiency microenterprise is not very high, since Wi-Fi advertising-which limited by a small router coverage area-is mainly used. Moreover, because lack money, microenterprises have been using low-cost promote their products. Thus, enhancing effectiveness advertising, solving problem cost range views are now an...

The paper discusses the main stages of development and fundamental structure modern green roofs, advantages limitations creating features roofs in Vietnam other countries Asia-Pacific Region, concept “exploited roofing” Russia. authors assessed degree greening center (city) a number major megacities world 2015-2018, level St. Petersburg, qualitative research classification projects for various purposes scale. following key parameters were established, which determined differences...