Toad

Non-fiction by Tom Wille

Lake Attitash Management Plan; 2010

Management Plan and Comprehensive Lake Inventory of Lake Attitash in Amesbury/ Merrimac, M

My Responsibilities as a Twentieth-Century American

Non-fiction by Tom Wille

Learning and Exposure Affect Environmental Perception Less than Evolutionary Navigation Costs

Russell E. Jackson is with University of Idaho, Chéla R. Willey is with University of California Los Angeles, Lawrence K. Cormack is with UT Austin.Most behaviors are conditional upon successful navigation of the environment, which depends upon distance perception learned over repeated trials. Unfortunately, we understand little about how learning affects distance perception–especially in the most common human navigational scenario, that of adult navigation in familiar environments. Further, dominant theories predict mutually exclusive effects of learning on distance perception, especially when the risks or costs of navigation differ. We tested these competing predictions in four experiments in which we also presented evolutionarily relevant navigation costs. Methods included within- and between-subjects comparisons and longitudinal designs in laboratory and real-world settings. Data suggested that adult distance estimation rapidly reflects evolutionarily relevant navigation costs and repeated exposure does little to change this. Human distance perception may have evolved to reflect navigation costs quickly and reliably in order to provide a stable signal to other behaviors and with little regard for objective accuracy.Psycholog

Alien Registration- Willey, Marion E. (Sanford, York County)

https://digitalmaine.com/alien_docs/6055/thumbnail.jp

Two SMA-Actuated Miniature Mechanisms

The figures depict two miniature mechanisms actuated by strips made of shape-memory alloy (SMA). A typical SMA is a nickel-titanium alloy known by the trade name "Flexinol" or "Nitinol." In preparation for a typical application, a suitably sized and shaped piece of an SMA is deformed by a predetermined amount at the lower of two operating temperatures, then mounted in a mechanism. When stroking of the mechanism in one direction is desired, the piece of SMA is heated above a transition temperature to make it return to the "remembered" undeformed state. When stroking of the mechanism in the opposite direction is desired, the SMA is cooled below the transition temperature to make it return to the deformed state. Also, the SMA alloy chosen for a specific application is one that has a transition temperature somewhat above the ambient temperature, so that stroking in one direction or the opposite direction can be achieved by heating the SMA, or refraining from heating the SMA, respectively, above the transition temperature. In the present mechanisms as in typical other SMA mechanisms, the heating is effected by electric currents applied via electrical contacts at the ends of the SMA strips. The purpose served by the mechanism of Figure 1 is to lock or release a flexible latch attachment. In preparation for use in this mechanism, two initially straight SMA strips are deformed into curved springs that, when mounted in the mechanism at ambient temperature, clamp the knob at the lower end of the flexible latch attachment. When heated above their transition temperature by an electric current, the SMA strips return to their original straight configuration, thereby releasing the knob. This mechanism is redundant in the sense that as long as at least one of the two SMA strips straightens when commanded to do so, the knob is released. The mechanism of Figure 2 is suited to any of a variety of applications in which there are requirements for a small mechanism that affords lowtorque rotary actuation through a finite angular range. As shown here, the mechanism is used to rotate a coverlatch pin to a release position. In this case, a straight and flat SMA strip is torsionally deformed to a twist angle of about 90deg by use of a torsion bias spring. When the SMA strip is heated, it rotates to its original straight and flat condition

Soil availability, plant uptake and soil to plant transfer of 99Tc - A review

The fission yield of 99Tc from 239Pu and 235U is similar to that of 137Cs or 90Sr and it is therefore an important component of nuclear weapons fall-out, nuclear waste and releases from nuclear facilities. There is particular current interest in 99Tc transfer from soil to plants for: (a) environmental impact assessments for terrestrial nuclear waste repositories, and (b) assessments of the potential for phytoextraction of radionuclides from contaminated effluent and soil. Vascular plants have a high 99Tc uptake capacity, a strong tendency to transport it to shoot material and accumulate it in vegetative rather than reproductive structures. The mechanisms that control 99Tc entry to plants have not been identified and there has been little discussion of the potential for phytoextraction of 99Tc contaminated effluents or soil. Here we review soil availability, plant uptake mechanisms and soil to plant transfer of 99Tc in the light of recent advances in soil science, plant molecular biology and phytoextraction technologies. We conclude that 99Tc might not be highly available in the long term from up to 50% of soils worldwide, and that no single mechanism that might be easily targeted by recombinant DNA technologies controls 99Tc uptake by plants. Overall, we suggest that Tc might be less available in terrestrial ecosystems than is often assumed but that nevertheless the potential of phytoextraction as a decontamination strategy is probably greater for 99Tc than for any other nuclide of radioecological interest. © 2002 Elsevier Science Ltd. All rights reserved

Tuberculosis in Farm Poultry

Tuberculosis is to some extent prevalent here and there among the poultry flocks of Iowa. That has been brought out In the examination of birds, or their tissues, brought or sent for diagnosis to the veterinary laboratories of the Iowa State College and from field work by the veterlnary and poultry staff of the agricultural extension department. From November 1, 1909, to June 30, 1912, the pathology laboratory examined the tissues of seventy-three birds, two of which, or 2.7% were found to be affected with tuberculosis. From July 1, 1912, to September 11, 1915, two hundred fifty-five fowls were examined and It was found that In forty-three, or 16.86%, tuberculosis was the cause of sickness or death. From September 11, 1915, to June 1, 1918, there were examined In the laboratory of the Department of Veterinary Investigation two hundred and twenty-seven fowls. Eighty-three or 36.57% were found to be affected with tuberculosis. These birds or tissues came from many different flocks In various parts of the state

Miniature Linear Actuator for Small Spacecraft

A report discusses the development of a kit of mechanisms intended for use aboard future spacecraft having masses between 10 and 100 kg. The report focuses mostly on two prototypes of one of the mechanisms: a miniature linear actuator based on a shape-memory-alloy (SMA) wire. In this actuator, as in SMA-wire actuators described previously in NASA Tech Briefs, a spring biases a moving part toward one limit of its stroke and is restrained or pulled toward the other limit of the stroke by an SMA wire, which assumes a slightly lesser or greater "remembered" length, depending on whether or not an electric current is applied to the wire to heat it above a transition temperature. Topics addressed in the report include the need to develop mechanisms like these, the general approach to be taken in designing SMA actuators, tests of the two prototypes of the miniature linear actuators, and improvements in the second prototype over the first prototype resulting in reduced mass and increased stroke. The report also presents recommendations for future development, briefly discusses problems of tolerances and working with small parts, states a need for better understanding of behaviors of SMAs, and presents conclusions