Acoustically swept rotor

Impulsive noise reduction is provided in a rotor blade by acoustically sweeping the chord line from root to tip so that the acoustic radiation resulting from the summation of potential singularities used to model the flow about the blade tend to cancel for all times at an observation point in the acoustic far field

The Disembodied Subject: Resistance to Norms of Hegemonic Identity Construction in Carmen Naranjo’s Diario de una multitud

Costa Rica, whose civil war ended in 1948, represents a distinct literary space in which problematics of subjectivity were debated long before such dialectics appeared overtly in the rest of the isthmus. Carmen Naranjo’s novel Diario de una multitud (1974) is situated in this context, and her novel demonstrates a preoccupation with the heterogeneity of tico identity. Naranjo favors a collective representation of the urban citizenry. Through the perceptual liminality of the individual subject, the friction generated by its absence, the constant blurring that resets the boundaries of specific identities, and the disappearance of the private realm, Naranjo avoids inscribing lesbian desire. This novel has a disappeared lesbian. The urban multitudes are a spectacle of diversion that imply a mise en abyme of sexual desire, a speculation on the impossibility of liberating that desire. The blurred melancholy of the multitude replaces the blurred lesbian haunting the pages but never appearing in them. The splintered subjectivities, absence of sexual markers, and secretiveness of private lives imply the violence with which sexuality has been repressed. This study argues that denying embodiment to the subject(s) of Diario’s narration simultaneously obscures the lesbian and resists the violence that definition and even self-definition perpetrate on the subject

Metamorphic and Deformational History of the Standing Pond and Putney Volcanics in Southeastern Vermont

Guidebook for field trips in Vermont: New England Intercollegiate Geological Conference, 79th annual meeting, October 16, 17 and 18, 1987: Trips A-

Hovering impulsive noise: Some measured and calculated results

In-plane impulsive noise radiating from a hovering model rotor was measured in an anechoic environment. The hover acoustic signature was compared with existing theoretical prediction models with previous forward flight experiments using the same model rotor. These hover tests showed good experimental consistency with forward flight measurements, both in pressure level, and waveform character, over the range of Mach numbers tested (0.8 to 1.0). Generally poor correlation, however, was confirmed with current linear theory prediction efforts. Failure to predict both the peak pressure levels and the shape was reported, especially with increasing tip Mach number

Review and analysis of the DNW/Model 360 rotor acoustic data base

A comprehensive model rotor aeroacoustic data base was collected in a large anechoic wind tunnel in 1986. Twenty-six microphones were positioned around the azimuth to collect acoustic data for approximately 150 different test conditions. A dynamically scaled, blade-pressure-instrumented model of the forward rotor of the BH360 helicopter simultaneously provided blade pressures for correlation with the acoustic data. High-speed impulsive noise, blade-vortex interaction noise, low-frequency noise, and broadband noise were all captured in this extensive data base. Trends are presentes for each noise source, with important parametric variations. The purpose of this paper is to introduce this data base and illustrate its potential for predictive code validation

The Efficacy of Guided Imagery / Visualization & Journaling in Patients with Irritable Bowel Syndrome

A guided-imagery/visualization and journaling protocol, as parrtof a multi-component treatment program, was tested as a treatment for irritable bowel syndrome (IBS). IBS is a functional disorder of the lower gastrointestinal tract characterized by abdominal pain and altered bowel habits. It has worldwide prevalence rates ranging between 9 and 23%. It is the most frequently diagnosed GI disorder in both clinical settings and the general population, accounting for an estimated 28% of patients seen by gastroenterologists and approximately 12% of those seen in primary care settings. In comparison to other diseases in the United States, IBS is more prevalent than diabetes (3%), asthma (4%), heart disease (8%), and hypertension (11 %). IBS effects an estimated 10-20% of adolescents and adults, with 14-24% incidence in females and 5-19% in males-a discrepancy that is also common to males in India and Japan and which may reflect increased healthcare-seeking behavior in women. The overall prevalence of IBS fluctuates with age; a prevalence rate of 14% occurs in individuals between 15 and 44 years old, and decreases to approximately 9% after age 45

Helicopter model rotor-blade vortex interaction impulsive noise: Scalability and parametric variations

Acoustic data taken in the anechoic Deutsch-Niederlaendischer Windkanal (DNW) have documented the blade vortex interaction (BVI) impulsive noise radiated from a 1/7-scale model main rotor of the AH-1 series helicopter. Averaged model scale data were compared with averaged full scale, inflight acoustic data under similar nondimensional test conditions. At low advance ratios (mu = 0.164 to 0.194), the data scale remarkable well in level and waveform shape, and also duplicate the directivity pattern of BVI impulsive noise. At moderate advance ratios (mu = 0.224 to 0.270), the scaling deteriorates, suggesting that the model scale rotor is not adequately simulating the full scale BVI noise; presently, no proved explanation of this discrepancy exists. Carefully performed parametric variations over a complete matrix of testing conditions have shown that all of the four governing nondimensional parameters - tip Mach number at hover, advance ratio, local inflow ratio, and thrust coefficient - are highly sensitive to BVI noise radiation