2,686 research outputs found
Electroplating on titanium alloy
Activation process forms adherent electrodeposits of copper, nickel, and chromium on titanium alloy. Good adhesion of electroplated deposits is obtained by using acetic-hydrofluoric acid anodic activation process
Solar energy absorption characteristics and the effects of heat on the optical properties of several coatings
The solar energy absorption characteristics of several high temperature coatings were determined and effects of heat on these coatings were evaluated. Included in the investigation were an electroplated alloy of black chrome and vanadium, electroplated black chrome, and chemically colored 316 stainless steel. Each of the coatings possessed good selective solar energy absorption properties at laboratory ambient temperature. Measured at a temperature of 700 K (800 F), the emittances of black chrome, black chrome vanadium, and colored stainless steel were 0.11, 0.61, and 0.15, respectively. Black chrome and black chrome vanadium did not degrade optically in the presence of high heat (811 K (1000 F)). Chemically colored stainless steel showed slight optical degradation when exposed to moderately high heat (616 K (650 F)0, but showed more severe degradation at exposure temperatures beyond this level. Each of the coatings showed good corrosion resistance to a salt spray environment
Investigation of the Technical Micronics Control /TMC/ Process for Electropolishing Various Metals
Technical micronics control process for electropolishing metals and alloy
Solar absorption characteristics of several coatings and surface finishes
Solar absorption characteristics are established for several films potentially favorable for use as receiving surfaces in solar energy collectors. Included in the investigation were chemically produced black films, black electrodeposits, and anodized coatings. It was found that black nickel exhibited the best combination of selective optical properties of any of the coatings studied. A serious drawback to black nickel was its high susceptibility to degradation in the presence of high moisture environments. Electroplated black chrome generally exhibited high solar absorptivities, but the emissivity varied considerably and was also relatively high under some conditions. The black chrome had the greatest moisture resistance of any of the coatings tested. Black oxide coatings on copper and steel substrates showed the best combination of selective optical properties of any of the chemical conversion films studied
Environmental durability of electroplated black chromium
A study was undertaken to determine the durability of nickel-black chromium plated aluminum in an outdoor rural industrial, and seacoast environment. Test panels were exposed to these environments for 60, 36, and 13 months, respectively. The results of this study showed that no significant optical degradation occurred from exposure to either of these environments, although a considerable amount of corrosion occurred on the panels exposed to the seacoast environment. The rural and industrial atmosphere produced only a slight amount of corrosion on test panels
Independent Orbiter Assessment (IOA): Assessment of the data processing system FMEA/CIL
The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the Data Processing System (DPS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL baseline with proposed Post 51-L updates included. A resolution of each discrepancy from the comparison is provided through additional analysis as required. The results of that comparison is documented for the Orbiter DPS hardware
Prediction Markets: Alternative Mechanisms for Complex Environments with Few Traders
Double auction prediction markets have proven successful in large-scale applications such as elections and sporting events. Consequently, several large corporations have adopted these markets for smaller-scale internal applications where information may be complex and the number of traders is small. Using laboratory experiments, we test the performance of the double auction in complex environments with few traders and compare it to three alternative mechanisms. When information is complex we find that an iterated poll (or Delphi method) outperforms the double auction mechanism. We present five behavioral observations that may explain why the poll performs better in these settings
A head restraint device for vestibular studies
Head restraint device based on vacuum bladder technique for use in vestibular studie
Alien Registration- Lowery, James J. (Portland, Cumberland County)
https://digitalmaine.com/alien_docs/22122/thumbnail.jp
A history of the first fifteen years of community colleges in Iowa 1965-1980
The purpose of this study was to trace the events of the transition from the locally-owned public junior colleges in Iowa to the state system of community colleges, and to analyze and record the first 15 years of operation of the new comprehensive community colleges. A review was also made of the two-year colleges on the national level and of earlier efforts to provide postsecondary education at the two-year level in Iowa;The major sources of information were from national and state studies of two-year colleges, the Iowa General Assembly, the Iowa State Board of Education minutes, records from the colleges, annual reports from the Iowa Department of Public Instruction and from personal interviews;Major factors influencing the transition were: (1) the limited access to the locally-owned junior colleges; (2) the movement in the state from a rural to an industrial economy; (3) the infusion of federal dollars into vocational education; and (4) the need to expand postsecondary educational opportunities in the state, especially in vocational education;Institutional topics given major consideration during the 15-year period of operation were students and student services, faculty, instructional programs, campus developments, finances, governance, and the status of the graduates;The findings of the study revealed that over the 15-year period the number of full-time equivalent students attending two-year colleges in Iowa grew from 11,136 in 1966-67 to 48,050 during 1979-80. The headcount enrollment in 1979-80 grew to 498,061. The enrollment in college transfer courses remained rather constant while vocational enrollment showed tremendous growth. The number of vocational programs grew from 12 in 1945 to 145 in 1980. Education for adults of all ages grew tremendously with 48,689 individuals earning a high school diploma or the equivalent between 1966 and 1980. Follow-up studies of the graduates entering employment, showed 85.8 percent were employed in jobs related to their training. Of the graduates transferring to either of the three state universities, a slight drop in grade point average occurred during the first term, but in succeeding terms the grade point improved
- …