Preliminary analysis of measured sound propagation over various seasonal snow covers

Measurements of acoustic pulse propagation in the 5 to 500-Hz frequency band were conducted under various snow cover conditions during the 1989 to 1990 winter in New Hampshire. The objective was to determine the effect of snow cover thickness and other snow properties on the absorption of acoustic pulses. Blank pistol shots were used as the source of the acoustic waves, and geophones and microphones in an 80 m-long linear array served as receivers. Snow thicknesses ranged from 0.05 to 0.35 m, and densities varied from 100 to 350 kg m(sup -3) during the 10 separate measurement days. Preliminary analysis indicates that the peak pulse amplitude decayed in proportion to approx. gamma (sup -1.7) for most conditions and that the acoustic-to-seismic ratios varied from about 4 to 15 x 10(exp -6) m s(sup -1) Pa(sup -1). Theoretical waveforms were calculated for propagation in a homogeneous atmosphere using Attenborough's model of ground impedance. An automatic fitting procedure for the normalized experimental and theoretical waveforms was used to determine the effective flow resistivity of the snow covers, and gave values of 10 to 35 kN s m(sup -4), in agreement with earlier results

Assessing the Impact of Organizational Practices on the Productivity of University Technology Transfer Offices: An Exploratory Study

We present quantitative and qualitative evidence (field research) on university technology transfer offices (TTOs). These offices negotiate licensing agreements with firms to commercialize university-based technologies. A stochastic frontier production function framework is used to assess the relative productivity of 113 university TTOs. Our field research provided a useful reality check on the specification of the econometric model. The empirical findings imply that licensing activity is characterized by constant returns to scale. Environmental and institutional factors appear to explain some of the variation in TTO efficiency. Relative productivity may also depend on organizational practices in university management of intellectual property, which potentially attenuate palpable differences in the motives, incentives, and organizational cultures of the parties to licensing agreements. Unfortunately, there are no existing data on such practices, so we rely on inductive, qualitative methods to identify them. We present detailed information on our use of these methods. This information may be useful to economists who are contemplating fieldwork. Based on 55 interviews of managers/entrepreneurs and administrators at five research universities, we conclude that the most critical organizational factors are likely to be reward systems for faculty, TTO staffing and compensation practices, and actions taken by administrators to extirpate informational and cultural barriers between universities and firms.

Design considerations for space radiators based on the liquid sheet (LSR) concept

Concept development work on space heat rejection subsystems tailored to the requirements of various space power conversion systems is proceeding over a broad front of technologies at NASA LeRC. Included are orbital and planetary surface based radiator concepts utilizing pumped loops, a variety of heat pipe radiator concepts, and the innovative liquid sheet radiator (LSR). The basic feasibility of the LSR concept was investigated in prior work which generated preliminary information indicating the suitability of the LSR concept for space power systems requiring cycle reject heat to be radiated to the space sink at low-to-mid temperatures (300 to 400 K), with silicon oils used for the radiator working fluid. This study is directed at performing a comparative examination of LSR characteristics as they affect the basic design of low earth orbit solar dynamic power conversion systems. The power systems considered were based on the closed Brayton (CBC) and the Free Piston Stirling (FPS) cycles, each with a power output of 2 kWe and using previously tested silicone oil (Dow-Corning Me2) as the radiator working fluid. Conclusions indicate that, due to its ability for direct cold end cooling, an LSR based heat rejection subsystem is far more compatible with a Stirling space power system than with a CBC, which requires LSR coupling by means of an intermediate gas/liquid heat exchanger and adjustment of cycle operating conditions

Mutiny on the Bounty - A Cornucopia of Fruits and Invectives

The article was originally published in The Pitcairn Log.On April 28, 1789, the most infamous of mutinies occurred in the South Pacific Ocean within sight of an erupting volcano on Tofua. Acting Lieutenant Fletcher Christian deposed “Captain” William Bligh and eighteen men in the Bounty’s 23-foot launch to an almost certain death. After an unsuccessful settlement attempt on Tubuai, 350 miles south of Tahiti, Christian and eight mutineers, together with 19 Polynesians (six men, twelve women, and one infant girl), circuitously rediscovered Pitcairn Island on January 15, 1790. Being 212 miles east of its recorded position, this remote, isolated, and deserted island was an ideal outpost for renegades of the British Admiralty. Miraculously, Bligh sailed the launch successfully to Coupang, Timor, and eventually returned to England on March 14, 1790. Whereas Christian established a nascent settlement on a level patch of land above Bounty Bay accessible via an arduous path that became known as the “Hill of Difficulty.” While the story of the mutiny on the Bounty is well known, this version focuses on fruits as backdrop and springboard to conflict occurring during and after the mutiny. Bounty enthusiasts know that the original purpose of this voyage was to secure breadfruit saplings for the British West Indies as a cheap food source for plantation slaves. Sir Joseph Banks, President of the Royal Society in London and life-long supporter of William Bligh spearheaded this economic-botanical expedition. Beyond breadfruit, other fruits including coconuts and pumpkins became the impetus for igniting Bligh’s explosive temper. This account of the mutiny on the Bounty and its aftermath uses fruits as an unusual framework to view this romance on the high seas. Just note Richard Crane and David Essex’s concept album and musical about the H.M.S. Bounty in 1983 and 1985, respectively, which supports this notion. The album/musical included songs and scenes titled “Breadfruit” and “Pumpkin,” so the fruits motif is not an entirely an off-the-wall association

MARY ANN CHRISTIAN, EXERCISING SOCIAL AND SPATIAL AGENCY: An isolated island case

Article originally published in ShimaMary Ann Christian (1793-1866) was the only daughter of chief Bounty mutineer Fletcher Christian and his Tahitian consort Mauatua who settled on Pitcairn Island in 1790. After a violent first decade, and one death to a natural cause, the male population was reduced to a sole male survivor – John Adams. This created a female- dominated milieu within which Many Ann Christian operated with a strong degree of agency across social hierarchies involving island and empire actors, and spatially with her on- and off-island movements. While still a teenager, Mary Ann Christian became the inspiration for Mary Russell Mitford’s exquisite protagonist in Christina: The Maid of the South Seas: A Poem (1811). Almost three decades later, Lieutenant Lowry visiting from the Sparrowhawk dubbed her a cantankerous “old maid” for her concern that girls aged 13, 14, and 15 were too young for marriage; male dominance had reasserted itself. Primary and other credible sources, including demographics, document the events surrounding Herstory

Cytoplasmic DNA in the unfertilized sea urchin egg: Physical properties of circular mitochondrial DNA and the occurrence of catenated forms

The mitochondrial DNA in the unfertilized egg of the sea urchin Lytechinus pictus is present in an amount approximately seven times that of the haploid nuclear DNA.(1) The mitochondrial DNA has a higher buoyant density than the nuclear DNA and consists of circular duplex molecules of a uniform size of about 5µ. The circular DNA has been recovered(1) in both the intact (closed) and nicked (open) states characteristic of the circular duplex viral DNA's(2) and the mitochondrial DNA's from birds and mammals.(3, 4

An Empirical Analysis of the Propensity of Academics to Engage in Informal University Technology Transfer

Formal university technology transfer mechanisms, through licensing agreements, research joint ventures, and university-based startups, have attracted considerable attention in the academic literature. Surprisingly, there has been little systematic empirical analysis of the propensity of academics to engage in informal technology transfer. This paper presents empirical evidence on the determinants of three types of informal technology transfer by faculty members: knowledge transfer, joint publications with industry scientists, and consulting. We find that male and tenured faculty members are more likely to engage in all three forms of informal technology transfer. We also find that academics who allocate a relatively higher percentage of their time to grants-related research are more likely to engage in informal commercial knowledge transfer.

An architecture for intelligent health assessment enabled IEEE 1451 compliant smart sensors

As systems become increasingly complex and costly, potential failure mechanisms and indicators are numerous and difficult to identify, while the cost of loss is very expensive - human lives, replacement units, and impacts to national security. In order to ensure the safety and long-term reliability of vehicles, structures, and devices attention must be directed toward the assessment and management of system health. System health is the key component that links data, information, and knowledge to action. Integrated Systems Health Management (ISHM) doctrine calls for comprehensive real-time health assessment and management of systems where the distillation of raw data into information takes place within sensors and actuators. This thesis develops novel field programmable health assessment capability for sensors and actuators in ISHM. Health assessment and feature extraction algorithms are implemented on a sensor or actuator through the Embedded Routine Manager (ERM) API. Algorithms are described using Health Electronic Datasheets (HEDS) to provide more flexible run-time operation. Interfacing is accomplished through IEEE Standard 1451 for Smart Sensors and Actuators, connecting ISHM with the instrumentation network of the future. These key elements are validated using exemplar algorithms to detect noise, spike, and flat-line events onboard the ISHM enabled Methane Thruster Testbed Project (MTTP) at NASA Stennis Space Center in Mississippi