The Equipment Needs of the Standards for Technological Literacy

These goals were analyzed to produce a standard equipment list for CATTS to recommend for implementation in participating states. It sought to: 1. Determine the equipment needs for elementary education programs implementing the Standards for Technological Literacy; 2. Determine the equipment needs for middle school education programs implementing the Standards for Technological Literacy; 3. Determine the equipment needs for high school education programs implementing the Standard for Technological Literacy

Nuclear Energy and its History: Past Consequences, Present Inadequacies and a Perspective for Success

An attempt is made to locate nuclear technology within a logical context considering history, risks, societal catastrophes and perspectives: the need is identified for a new direction in the exploitation in order to restore the role in energy production. We depict the situation coming from a marvelous history of discoveries started at the beginning of the XX century; heroes are recalled who made possible something that is inconceivable today: design, construction and production of electricity in a few years; that history was tainted by intentional nuclear explosions, i.e. the original sin that we are now paying. Then, we attempt to show that the societal risk is an inherent part of the civilization. Restoring the public trust (towards nuclear fission technology) by matching nuclear safety with the current technological status and advancers in risk assessment is the key objective. The “independent assessment”, or a principle for the exploitation of nuclear energy already stated in the 50’s of the previous century, shall then re-appear. This is used to erect the signpost for a “dynamic barricade” to further reduce the risk of operation of nuclear reactors and to match the design with current technological capabilities and with the frontiers of the research

A computerized Langmuir probe system

For low pressure plasmas it is important to record entire single or double Langmuir probe characteristics accurately. For plasmas with a depleted high energy tail, the accuracy of the recorded ion current plays a critical role in determining the electron temperature. Even for high density Maxwellian distributions, it is necessary to accurately model the ion current to obtain the correct electron density. Since the electron and ion current saturation values are, at best, orders of magnitude apart, a single current sensing resistor cannot provide the required resolution to accurately record these values. We present an automated, personal computer based data acquisition system for the determination of fundamental plasma properties in low pressure plasmas. The system is designed for single and double Langmuir probes, whose characteristics can be recorded over a bias voltage range of ±70 V with 12 bit resolution. The current flowing through the probes can be recorded within the range of 5 nA–100 mA. The use of a transimpedance amplifier for current sensing eliminates the requirement for traditional current sensing resistors and hence the need to correct the raw data. The large current recording range is realized through the use of a real time gain switching system in the negative feedback loop of the transimpedance amplifier

Power generation costs and ultimate thermal hydraulic power limits in hypothetical advanced designs with natural circulation

Maximum power limits for hypothetical designs of natural circulation plants can be described analytically. The thermal hydraulic design parameters are those which limit the flow, being the elevations, flow areas, and loss coefficients. WE have found some simple ``design`` equations for natural circulation flow to power ratio, and for the stability limit. The analysis of historical and available data for maximum capacity factor estimation shows 80% to be reasonable and achievable. The least cost is obtained by optimizing both hypothetical plant performance for a given output,a nd the plant layout and design. There is also scope to increase output and reduce cost by considering design variations of primary and secondary pressure, and by optimizing component elevations and loss coefficients. The design limits for each are set by stability and maximum flow considerations, which deserve close and careful evaluation

The Iowa Homemaker vol.4, no.11

Table of Contents St. Patrick Inspires a Shamrock Luncheon by Alice Ericson and Julia B. Whiteside, page 1 Do You Test Your Textiles? by Mrs. Avis Duffey, page 2 Farm and Home Week Pays by Anne Westrom, page 2 Coffee in a Multitude of Ways by Adele Herbst, page 3 With the Iowa State Home Economics Association, page 4 Another Fuel – Bottled Gas by Florence Forbes, page 5 Iowa Child Welfare Research Station by Agnes Crain, page 6 Editorial, page 7 The Eternal Question, page 8 Who’s There and Where, page

Bolt preload selection for pulsed-loaded vessel closures

Bounding, closed-form solutions are developed for selecting the bolt preload for a square, flat plate closure subjected to a pressure pulse load. The solutions consider the limiting case in which preload is primarily dependent on closure bending response as well as the limiting case in which preload depends on elastic bolt response. The selection of bolt preload is illustrated. Also presented in the paper is a detailed finite element analysis of dynamically loaded, bolted circular closure. The responses of the structure, closure, and bolts are included, and results are obtained for various preloads. The analysis illustrates a method of bolt preload modeling for use in general finite element computer programs

Sodium and potassium intake patterns and trends in South Korea

We examined major trends and patterns regarding sodium and potassium intake and the ratio of sodium and potassium in the diets of South Koreans. We analyzed detailed 24-hour dietary recall data collected from 10,267; 8,819; and 9,264 subjects ages two years and older in the 1998, 2005, and 2009 Korean National Health and Nutrition Examination Surveys, respectively. Mean sodium intake did not change significantly between 1998 and 2009 (4.6 g/d vs 4.7 g/d), while potassium intake increased significantly [2.6 g/d vs. 2.9 g/d (p < 0.001)]. The major dietary sodium sources were kimchi, salt, soy sauce, and soybean paste, and most potassium came from unprocessed foods (white rice, vegetables, kimchi, and fruits). About 50 percent of the participants consumed 4 or more grams of sodium per capita per day. The proportion of respondents consuming 4 to 6 grams of potassium per capita per day increased from 10.3 percent in 1998 to 14.3 percent in 2009 (p < 0.001), and the sodium-potassium ratio decreased from 1.88 to 1.71 (p < 0.001). One major implication is that efforts to reduce sodium in processed foods will be ineffective and future efforts must focus on both education to reduce use of sodium in food preparation and sodium replacement in salt, possibly with potassium

Prevalence and energy intake from snacking in Brazil: analysis of the first nationwide individual survey

Snacking has increased globally. We examine snacking patterns and common snack foods in Brazil