Window acoustic study for advanced turboprop aircraft

An acoustic analysis was performed to establish window designs for advanced turboprop powered aircraft. The window transmission loss requirements were based on A-weighted interior noise goals of 80 and 75 dBA. The analytical results showed that a triple pane window consisting of two glass outer panes and an inner pane of acrylic would provide the required transmission loss and meet the sidewall space limits. Two window test articles were fabricated for laboratory evaluation and verification of the predicted transmission loss. Procedures for performing laboratory tests are presented

Sonic environment of aircraft structure immersed in a supersonic jet flow stream

Test methods for determining the sonic environment of aircraft structure that is immersed in the flow stream of a high velocity jet or that is subjected to the noise field surrounding the jet, were investigated. Sonic environment test data measured on a SCAT 15-F model in the flow field of Mach 1.5 and 2.5 jets were processed. Narrow band, lateral cross correlation and noise contour plots are presented. Data acquisition and reduction methods are depicted. A computer program for scaling the model data is given that accounts for model size, jet velocity, transducer size, and jet density. Comparisons of scaled model data and full size aircraft data are made for the L-1011, S-3A, and a V/STOL lower surface blowing concept. Sonic environment predictions are made for an engine-over-the-wing SST configuration

Analytical study of interior noise control by fuselage design techniques on high-speed, propeller-driven aircraft

The acoustical treatment mass penalties required to achieve an interior noise level of 80 dBA for high speed, fuel efficient propfan-powered aircraft are determined. The prediction method used is based on theory developed for the outer shell dynamics, and a modified approach for add-on noise control element performance. The present synthesis of these methods is supported by experimental data. Three different sized aircraft are studied, including a widebody, a narrowbody and a business sized aircraft. Noise control penalties are calculated for each aircraft for two kinds of noise control designs: add-on designs, where the outer wall structure cannot be changed, and advanced designs where the outer wall stiffness level and the materials usage can be altered. For the add-on designs, the mass penalties range from 1.7 to 2.4 percent of the takeoff gross weight (TOGW) of the various aircraft, similar to preliminary estimates. Results for advanced designs show significant reductions of the mass penalties. For the advanced aluminum designs the penalties are 1.5% of TOGW, and for an all composite aircraft the penalties range from 0.74 to 1.4% of TOGW

Urban Planning and Sustainable Storm Water Management: Gaps and Potential for Integration for Climate Adaptation Strategies

While climate change urges cities to define appropriate strategies for climate adaptation, urban planning practices are still unable to encompass a broader understanding of hydraulic hazards and to exploit the mitigation potential of nature-based solutions (NBS) for stormwater management. This inability is particularly deep in the Italian context, where the integration of climate adaptation strategies within urban planning is very limited; thus, one of the planner's overriding needs is to determine where NBS can be most effective. The objective of this paper is to identify key drivers and tools for the introduction of hydrological resilience assessments and sustainable storm water management in urban planning practices, as a contribution to climate adaptation strategies. Through a case study in the city of Bari, the paper proposes a method for identifying the most suitable urban areas for implementing NBS, i.e., areas where NBS are able to intercept runoff. On the other hand, the same approach allows one to evaluate in advance the impact of urban planning choices, or rather of the planned land use change. Finally, the planning tools that may favor the adoption of a NBS approach in urban planning are analyzed, with particular reference to the territorial landscape plan of the Apulia region and urban regeneration plans

Development and testing of cabin sidewall acoustic resonators for the reduction of cabin tone levels in propfan-powered aircraft

The use of Helmholtz resonators to increase the sidewall transmission loss (TL) in aircraft cabin sidewalls is evaluated. Development, construction, and test of an aircraft cabin acoustic enclosure, built in support of the Propfan Test Assessment (PTA) program, is described. Laboratory and flight test results are discussed. Resonators (448) were located between the enclosure trim panels and the fuselage shell. In addition, 152 resonators were placed between the enclosure and aircraft floors. The 600 resonators were each tuned to a propfan fundamental blade passage frequency (235 Hz). After flight testing on the PTA aircraft, noise reduction (NR) tests were performed with the enclosure in the Kelly Johnson Research and Development Center Acoustics Laboratory. Broadband and tonal excitations were used in the laboratory. Tonal excitation simulated the propfan flight test excitation. The resonators increase the NR of the cabin walls around the resonance frequency of the resonator array. Increases in NR of up to 11 dB were measured. The effects of flanking, sidewall absorption, cabin absorption, resonator loading of trim panels, and panel vibrations are presented. Resonator and sidewall panel design and test are discussed

Transport composite fuselage technology: Impact dynamics and acoustic transmission

A program was performed to develop and demonstrate the impact dynamics and acoustic transmission technology for a composite fuselage which meets the design requirements of a 1990 large transport aircraft without substantial weight and cost penalties. The program developed the analytical methodology for the prediction of acoustic transmission behavior of advanced composite stiffened shell structures. The methodology predicted that the interior noise level in a composite fuselage due to turbulent boundary layer will be less than in a comparable aluminum fuselage. The verification of these analyses will be performed by NASA Langley Research Center using a composite fuselage shell fabricated by filament winding. The program also developed analytical methodology for the prediction of the impact dynamics behavior of lower fuselage structure constructed with composite materials. Development tests were performed to demonstrate that the composite structure designed to the same operating load requirement can have at least the same energy absorption capability as aluminum structure

GABAergic Synaptic Transmission Regulates Calcium Influx During Spike-Timing Dependent Plasticity

Coincident pre- and postsynaptic activity of hippocampal neurons alters the strength of gamma-aminobutyric acid (GABAA)-mediated inhibition through a Ca2+-dependent regulation of cation-chloride cotransporters. This long-term synaptic modulation is termed GABAergic spike-timing dependent plasticity (STDP). In the present study, we examined whether the properties of the GABAergic synapses themselves modulate the required postsynaptic Ca2+ influx during GABAergic STDP induction. To do this we first identified GABAergic synapses between cultured hippocampal neurons based on their relatively long decay time constants and their reversal potentials which lay close to the resting membrane potential. GABAergic STDP was then induced by coincidentally (±1 ms) firing the pre- and postsynaptic neurons at 5 Hz for 30 s, while postsynaptic Ca2+ was imaged with the Ca2+-sensitive fluorescent dye Fluo4-AM. In all cases, the induction of GABAergic STDP increased postsynaptic Ca2+ above resting levels. We further found that the magnitude of this increase correlated with the amplitude and polarity of the GABAergic postsynaptic current (GPSC); hyperpolarizing GPSCs reduced the Ca2+ influx in comparison to both depolarizing GPSCs, and postsynaptic neurons spiked alone. This relationship was influenced by both the driving force for Cl− and GABAA conductance (which had positive correlations with the Ca2+ influx). The spike-timing order during STDP induction did not influence the correlation between GPSC amplitude and Ca2+ influx, which is likely accounted for by the symmetrical GABAergic STDP window

Medida Provisória e o Cinema Nacional: uma Nova Possibilidade de Representação

Trabalho de Conclusão de Curso apresentado ao Instituto Latino-Americano de Arte, Cultura e História da Universidade Federal da Integração Latino-Americana, como requisito parcial para a obtenção de título de licenciado em História - Licenciatura.A necessidade de uma indústria cinematográfica que represente a população brasileira de uma forma não estereotipada e pejorativa é de vital importância. O presente trabalho con siste em uma pesquisa qualitativa junto de um referencial teórico que tem como objetivo uma análise crítica do cinema enquanto fonte histórica, para melhor compreender os com portamentos e contextos aos quais a sociedade está sujeita e a forma com que o mesmo responde ao racismo institucional e estrutural que impera na sociedade. Partindo da pre missa de que o cinema nacional é uma extensão da sociedade, notou-se que a teoria do branqueamento e o mito da democracia racial por muito tempo representou uma socieda de brasileira que historicamente ignorou a presença negra como sendo fundamental para a construção do país. O filme Medida Provisória (2020) é utilizado como um objeto de pesquisa que elucida a representação negra dentro do cinema e possui uma relevância política e social para os filmes futuros. Também busca recuperar a identidade e o espaço dos negros e negras dentro da indústria do audiovisual brasileiro, tendo como objetivo uma maior representação racial e uma mudança social urgente

Loss, death, procreation and writing in the metafictive narrative of Rosa Montero

This work argues the purpose of writing for the female protagonists in Montero's Crónica del desamor, La hija del caníbal, La función Delta, Historia del Rey Transparente and La loca de la casa. This project attempts to uncover the connection between writing as a creative process and all its implications, such as its healing qualities for the protagonists. Finally, this study applies the feminist theories of Hélène Cixous, among others, to further connect women's personal and societal need to write. The first chapter of this paper includes a brief look at the author's life and her many accomplishments, as well as her role in women's narrative of post-Franco Spain. This chapter gives special attention to several commonalities of the women writers of the time, such as the use of metafiction, the form of writing fiction within a fiction, which Montero employs in all five novels. The second chapter encompasses the use of writing in order to confront loss. All the protagonists suffer from various losses, such as the loss of youth, love and innocence. Chapter three discusses the structure of the protagonists' writing within the scope of the novel as a metafiction. In the fourth chapter, I expand on the theme of death and how each protagonist uses writing to face their worries about dying, and how some of the protagonists employ writing to actually transcend death. Cixous' theory encourages women's writing through the body; in correlation with this theory, this chapter concentrates on the connection of the ability to procreate through writing. Finally, the conclusion illustrates how Montero actually portrays a positive outlook on life through the protagonists