Regeneration experiments below 10K in a regenerative-cycle cryocooler

At temperatures below 10K, regenerative cycle cryocoolers are limited by regeneration losses in the helium working fluid which result from the decreasing heat capacity of the regenerating material and the increasing density of helium. Experiments examining several approaches to improving the low-temperature regeneration in a four-stage regenerative cycle cooler constructed primarily of fiberglass materials are discussed. Using an interchangeable fourth stage, the experiments included configurations with multiple regeneration passages, and a static helium volume for increased heat capacity. Experiments using helium-3 as the working fluid and a Malone stage are planned. Results indicate that, using these techniques, it should be possible to construct a regenerative cycle cooler which will operate below 6K

A conceptual design study for the secondary mirror drive of the shuttle infrared telescope facility (SIRTF)

Various conceptual designs for the secondary mirror actuator system to be used in the Shuttle Infrared Telescope Facility (SIRTF) were evaluated. In addition, a set of design concepts was developed to assist in the solution of problems crucial for optimum performance of the secondary mirror actuator system. A specific conceptual approach was presented along with a plan for developing that approach and identifying issues of critical importance in the developmental effort

Shipboard fisheries management terminals

The needs of the National Marine Fisheries Service (NMGS), National Weather Service, and the U.S. Coast Guard for locational, biological, and environmental data were assessed. The fisheries conservation zones and the yellowfin tuna jurisdiction of the NMFS operates observer programs on foreign and domestic fishing vessels. Data input terminal and data transfer and processing technology are reviewed to establish available capability. A matrix of implementation options is generated to identify the benefits of each option, and preliminary cost estimates are made. Recommendations are made for incremental application of available off the shelf hardware to obtain improved performance and benefits within a well bounded cost. Terminal recommendations are made for three interdependent shipboard units emphasizing: (1) the determination of location and fishing activity; (2) hand held data inputting and formatting in the fishing work areas; and (3) data manipulation, merging, and editing

Carbon dioxide and water exchange rates by a wheat crop in NASA's biomass production chamber: Results from an 86-day study (January to April 1989)

Gas exchange measurements were taken for a 20 sq m wheat stand grown from seed to harvest in NASA's Biomass Production Chamber. Respiration of the wheat stand caused the CO2 concentrations to rise an average of 440 ppm during the 4-h dark period each day, or 7.2 umol/sq m/sec. Dark period respiration was sensitive to temperature changes and could be increased 70 to 75 percent by raising the temperature from 16 C to 24 C. Stand photosynthesis (measured from the rate of CO2 drawdown immediately after the lights came on each day) peaked at 27 umol/sq m/sec at 25 days after planting and averaged 15 umol/sq m/sec throughout the study. By combining the average light period photosynthesis and average dark period respiration, a net of 860 g or 470 liters of CO2 were fixed per day. Stand photosynthetic rates showed a linear increase with increasing irradiance (750 umol/sq m/sec PPF the highest level tested), with an average light compensation point after day 30 of 190 umol/sq m/sec. Stand photosynthesis decreased slightly when CO2 levels were decreased from 2200 to 800 ppm, but dropped sharply when CO2 was decreased below 700 to 800 ppm. Water production from stand transpiration peaked at 120 L/day near 25 days and averaged about 90 L/day, or 4.5 L/sq m/day throughout the study

The Ku Klux Klan\u27s portrayal of African Americans in mass media technology

The White supremacy group, the Ku Klux Klan was formed in 1866, after the end of the Civil War, in the small town of Pulaski, TN, by six ex-Confederate soldiers. Over the last 143 years the Klan has tried to take full advantage of the media in order to reach the largest audience possible to make its voice heard and spread its ideologies of hate towards African Americans and other minority groups. This study focuses on the similarities and differences in the Klan\u27s portrayal of African Americans between two great technological advances used by the Klan---motion pictures from the twentieth century and Internet websites from the twenty-first century. The study also takes into account the changes and advancements that have taken place in American society culturally that can aid in the explanation of the similarities and differences that exist in the Klan\u27s portrayal of African Americans in the mass media in order to justify the organization and use of recruitment.;The study was conducted using a qualitative content analysis and guided by the cultural approach to organizations theory, as well as semiotics. The sample included The Birth of a Nation, The Toll of Justice, www.kkk.com, www.kkkk.net.;The results of this study indicate that the Ku Klux Klan\u27s portrayal of African Americans in its media propaganda have not changed significantly from the twentieth century to the current time. The two films and two websites mirror each other in that one of each type of medium was found to be more overtly racist than the other of the same medium. Both mediums place great emphasis on the group\u27s denouncement of interracial romantic relationships, as well as African Americans being less intelligent and humane than whites. The biggest difference found was that the films rely heavily on pointing out the physical appearance of African Americans, while the websites focus more on facts and statistics .;The findings of this study would suggests that despite many claims that American society has taken great strides in accepting minorities and making changes that some aspects of our culture never change. Humans will always be afraid of losing power over their own lives, including their land, their family, their jobs and money, and even their respect as human being. This fear is especially strong when the loss may be caused by someone presumed to be less deserving than them. The Ku Klux Klan has continued to spin the same web for centuries to build a white supremacist culture based on fear and power. It has moved from print, to film, and in current time to the Internet, which in itself spins a web of reality created by the user connecting anything he or she wishes, and in the Klan\u27s case a world wide web of hatred and discrimination against African Americans and other minorities

Apple Pie Propaganda? The Smith–Mundt Act Before and After the Repeal of the Domestic Dissemination Ban

For over sixty years, the Smith–Mundt Act prohibited the U.S. Department of State and the Broadcasting Board of Governors (BBG) from disseminating government-produced programming within the United States over fears that these agencies would “propagandize” the American people. However, in 2013, Congress abolished the domestic dissemination ban, which has led to a heated debate about the role of the federal government in free public discourse. Although the 2013 repeal of the domestic dissemination ban promotes greater government transparency and may help counter anti-American sentiment at home, it also gives the federal government great power to covertly influence public opinion. To curb the potential harm of surreptitious government propaganda, while also preserving the benefits of repeal, this Note advocates for requiring the State Department and the BBG to clearly attribute any government-produced programming these agencies disseminate within the United States. This Note contends that attribution can be best accomplished in one of two ways: by passing new attribution legislation similar to that of the failed Truth in Broadcasting Act of 2005 or by expanding the judicially created government speech doctrine to require these agencies to properly attribute any materials they distribute to the American public

Proximate Composition of Seed and Biomass from Soybean Plants Grown at Different Carbon Dioxide (CO2) Concentrations

Soybean plants were grown for 90 days at 500, 1000, 2000, and 5000 ubar (ppm) carbon dioxide (CO2) and compared for proximate nutritional value. For both cultivars (MC and PX), seed protein levels were highest at 1000 (39.3 and 41.9 percent for MC and PX) and lowest at 2000 (34.7 and 38.9 percent for MC and PX). Seed fat (oil) levels were highest at 2000 (21.2 and 20.9 percent for MC and PX) and lowest at 5000 (13.6 and 16.6 percent for MC and PX). Seed carbohydrate levels were highest at 500 (31.5 and 28.4 percent for MC and PX) and lowest at 2000 (20.9 and 20.8 percent for MC and PX). When adjusted for total seed yield per unit growing area, the highest production of protein and carbohydrate occurred with MC at 1000, while equally high amounts of fat were produced with MC at 1000 and 2000. Seed set and pod development at 2000 were delayed in comparison to other CO2 treatments; thus the proportionately high fat and low protein at 2000 may have been a result of the delay in plant maturity rather than CO2 concentration. Stem crude fiber and carbohydrate levels for both cultivars increased with increased CO2. Leaf protein and crude fiber levels also tended to rise with increased CO2 but leaf carbohydrate levels decreased as CO2 was increased. The results suggest that CO2 effects on total seed yield out-weighed any potential advantages to changes in seed composition

Liberation Pragmatism: Dussel and Dewey in Dialogue

Enrique Dussel and John Dewey share commitments to philosophical theory and practice aimed at addressing human problems, democratic modes of inquiry, and progressive social reform, but also maintain productive differences in their fundamental starting point for political philosophy and their use of the social sciences. Dussel provides a corrective to Dewey’s Eurocentrism and to his tendency to underplay the challenges of incorporating marginalized populations by insisting that social and political philosophy begin from the perspective of the marginalized and excluded. Simultaneously, Dewey encourages a modest experimental and fallibilist approach to social transformation that promises more feasible social reforms than Dussel’s approach rooted in phenomenology and the critical social sciences

Effects of elevated atmospheric carbon dioxide concentrations on water and acid requirements of soybeans grown in a recirculating hydroponic system

Establishing mass budgets of various crop needs, i.e. water and nutrients, in different environments is essential for the Controlled Ecological Life Support System (CELSS). The effects of CO2 (500 and 1000 umol mol (exp -1)) on water and acid use (for pH control) by soybeans in a recirculating hydroponic system were examined. Plants of cvs. McCall and Pixie were grown for 90 days using the nutrient film technique (NFT) and a nitrate based nutrient solution. System acid use for both CO2 levels peaked near 4 weeks during a phase of rapid vegetative growth, but acid use decreased more rapidly under 500 compared to 1000 umol mol (exp GR) CO2. Total system water use by 500 and 1000 umol mol (exp -1) plants was similar, leaving off at 5 weeks and declining as plants senesced (ca. 9 weeks). However, single leaf transpiration rates were consistently lower at 1000 umol mol (exp -1). The data suggest that high CO2 concentrations increase system acid (and nutrient) use because of increased vegetative growth, which in turn negates the benefit of reduced water use (lower transpiration rates) per unit leaf area