13,618 research outputs found
Pseudacris clarkii
Number of Pages: 3Integrative BiologyGeological Science
From Scholarship Girls to Scholarship Women: Surviving the Contradictions of Class and Race in Academe
This article explores the dilemmas graduate education poses for women of working-class origin who come from different ethnic and racial backgrounds. It proceeds in a chronological narrative using examples from the authors\u27 personal experiences to make general points about how the intricate web of class, race, and gender relations shaped their experiences in higher education. Both women -- Cucidraz, a Chicana, and Pierce, a white woman -- struggle with the feelings of alienation and marginality as outsiders within the academy as well as their material needs for financial support. Their personal narratives reveal, as well, how race shapes their experiences in the academy. Racism renders Cuadraz\u27 class status visible, whereas whiteness masks Pierce\u27s background. Finally, the authors shift their focus from an examination of the structures which shaped their lives to an exploration of their attempts to find their own voices in academic work, and to resist the very structures which excluded their experiences as women from working-class backgrounds
Comparison of vibrations of a combination of solid-rocket launch vehicle and payload during a ground firing and launching
The results of a study into the environmental vibrations of a payload mounted on the Nike rocket launch vehicle were presented. Data were obtained during the flight acceptance test of the payload, the firing of the total vehicle in a special test stand, and the powered and unpowered flights of the vehicle. The vibrational response of the structure was measured. Data were also obtained on the fluctuating pressure on the outside surface of the vehicle and inside the forward and after ends of the rocket chamber. A comparison of the data from the three test conditions indicated that external pressure fluctuations were the major source of vibrations in the payload area, and pressure fluctuations within the rocket motor were the major source of vibrations contiguous to the payload area
Helicopter vibration suppression using simple pendulum absorbers on the rotor blade
A comprehensive anaytical design procedure for the installation of simple pendulums on the blades of a helicopter rotor to suppress the root reactions is presented. A frequency response anaysis is conducted of typical rotor blades excited by a harmonic variation of spanwise airload distributions as well as a concentrated load at the tip. The results presented included the effect of pendulum tuning on the minimization of the hub reactions. It is found that a properly designed flapping pendulum attenuates the root out-of-plane force and moment whereas the optimum designed lead-lag pendulum attenuates the root in-plane reactions. For optimum pendulum tuning the parameters to be determined are the pendulum uncoupled natural frequency, the pendulum spanwise location and its mass. It is found that the optimum pendulum frequency is in the vicinity of the excitation frequency. For the optimum pendulum a parametric study is conducted. The parameters varied include prepitch, pretwist, precone and pendulum hinge offset
Two phase detonation studies
An experimental study of the passage of a shock wave over a burning fuel drop is described. This includes high speed framing photographs of the interaction taken at 500,000 frames per second. A theoretical prediction of the ignition of a fuel drop by a shock wave is presented and the results compared with earlier experimental work. Experimental attempts to generate a detonation in a liquid fuel drop (kerosene)-liquid oxidizer drop (hydrogen peroxide)-inert gas-environment are described. An appendix is included which gives the analytical prediction of power requirements for the drop generator to produce certain size drops at a certain mass rate. A bibliography is also included which lists all of the publications resulting from this research grant
A Simulation Model to Evaluate the Impact of Provisioning on the Operational Availibility of Navy Training Devices
This paper presents the considerations that must be taken into account when formalizing a simulation model to determine the operational availability of a Navy training device. Consideration is given to those design and logistic support parameters that impact the general simulation model before it is formulated. These parameters, are then used as guidelines to collect and screen the data available for use in the general model. The general model is then translated into a computer simulation model. A specific training site is then chosen and data gathered to be used in the computer model. Design and logistic support parameters given consideration in this specific case were; component Mean-time-between-failures, repair capabilities (manual or automatic test equipment, and depot), spares provisioning, and repair or replacement times. The simulation model was then exercised by changing the provisioning on-site to determine its effect on the trainers operational availability. Of significant notice was the effects that provisioning had on manpower requirements in the area of maintenance
State Equity Crowdfunding and Investor Protection
Since Kansas enacted the first blue sky law in 1911, securities regulation has sought to protect investors from fraud and speculation. Historically, this meant precluding substantial numbers of small businesses from raising capital in the form of equity investments. In order to facilitate small-business capital formation, in 2012 the federal government passed the Jumpstart Our Business Startups Act (JOBS Act). Although Title III of the JOBS Act required the Securities and Exchange Commission to undergo rulemaking to allow for small-dollar equity investments, the agency dragged its feet. In the interim, states anxious to jumpstart their own economies took the initiative. Legislation has now been enacted in over half the states. Although a laudable attempt to make raising capital easier, this legislation potentially provides an avenue for fraudulent offerings and significant investor losses. This Comment reviews the historical context in which state crowdfunding exemptions have been passed and compares enacted state laws to the JOBS Act’s requirements. It argues that in order to effectively prevent fraud while enabling small-business capital formation, states should adopt specific protection measures in their crowdfunding laws. These prophylactic measures, including requirements on both issuers and intermediaries, as well as protections for investors, promise to better help business while also protecting investors
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