Design of helicopter rotor blades for optimum dynamic characteristics

NASA Technical Reports Server (NTRS)

Peters, D. A.; Ko, T.; Korn, A.; Rossow, M. P.

1985-01-01

The mass and stiffness distributions for helicopter rotor blades are tailored in such a way to give a predetermined placement of blade natural frequencies. The optimal design is pursued with respect of minimum weight, sufficient inertia, and reasonable dynamic characteristics. Finite element techniques are used as a tool. Rotor types include hingeless, articulated, and teetering.

Rapid Response Risk Assessment in New Project Development

NASA Technical Reports Server (NTRS)

Graber, Robert R.

2010-01-01

A capability for rapidly performing quantitative risk assessments has been developed by JSC Safety and Mission Assurance for use on project design trade studies early in the project life cycle, i.e., concept development through preliminary design phases. A risk assessment tool set has been developed consisting of interactive and integrated software modules that allow a user/project designer to assess the impact of alternative design or programmatic options on the probability of mission success or other risk metrics. The risk and design trade space includes interactive options for selecting parameters and/or metrics for numerous design characteristics including component reliability characteristics, functional redundancy levels, item or system technology readiness levels, and mission event characteristics. This capability is intended for use on any project or system development with a defined mission, and an example project will used for demonstration and descriptive purposes, e.g., landing a robot on the moon. The effects of various alternative design considerations and their impact of these decisions on mission success (or failure) can be measured in real time on a personal computer. This capability provides a high degree of efficiency for quickly providing information in NASA s evolving risk-based decision environment

Aerodynamics of the Viggen 37 aircraft. Part 1: General characteristics at low speed

NASA Technical Reports Server (NTRS)

Karling, K.

1986-01-01

A description of the aerodynamics of the Viggen 37 and its performances, especially at low speeds is presented. The aerodynamic requirements for the design of the Viggen 37 aircraft are given, including the basic design, performance requirement, and aerodynamic characteristics, static and dynamic load test results and flight test results. The Viggen 37 aircraft is designed to be used for air attack, surveillance, pursuit, and training applications. It is shown that this aircraft is suitable for short runways, and has good maneuvering, acceleration, and climbing characteristics. The design objectives for this aircraft were met by utilizing the effect produced by the interference between two triangular wings, positioned in tandem.

An analysis of lateral stability in power-off flight with charts for use in design

NASA Technical Reports Server (NTRS)

Zimmerman, Charles H

1937-01-01

The aerodynamic and mass factors governing lateral stability are discussed and formulas are given for their estimation. Relatively simple relationships between the governing factors and the resulting stability characteristics are presented. A series of charts is included with which approximate stability characteristics may be rapidly estimated. The effects of the various governing factors upon the stability characteristics are discussed in detail. It is pointed out that much additional research is necessary both to correlate stability characteristics with riding, flying, and handling qualities and to provide suitable data for accurate estimates of those characteristics of an airplane while it is in the design stage.

Investigating the impact of design characteristics on statistical efficiency within discrete choice experiments: A systematic survey.

PubMed

Vanniyasingam, Thuva; Daly, Caitlin; Jin, Xuejing; Zhang, Yuan; Foster, Gary; Cunningham, Charles; Thabane, Lehana

2018-06-01

This study reviews simulation studies of discrete choice experiments to determine (i) how survey design features affect statistical efficiency, (ii) and to appraise their reporting quality. Statistical efficiency was measured using relative design (D-) efficiency, D-optimality, or D-error. For this systematic survey, we searched Journal Storage (JSTOR), Since Direct, PubMed, and OVID which included a search within EMBASE. Searches were conducted up to year 2016 for simulation studies investigating the impact of DCE design features on statistical efficiency. Studies were screened and data were extracted independently and in duplicate. Results for each included study were summarized by design characteristic. Previously developed criteria for reporting quality of simulation studies were also adapted and applied to each included study. Of 371 potentially relevant studies, 9 were found to be eligible, with several varying in study objectives. Statistical efficiency improved when increasing the number of choice tasks or alternatives; decreasing the number of attributes, attribute levels; using an unrestricted continuous "manipulator" attribute; using model-based approaches with covariates incorporating response behaviour; using sampling approaches that incorporate previous knowledge of response behaviour; incorporating heterogeneity in a model-based design; correctly specifying Bayesian priors; minimizing parameter prior variances; and using an appropriate method to create the DCE design for the research question. The simulation studies performed well in terms of reporting quality. Improvement is needed in regards to clearly specifying study objectives, number of failures, random number generators, starting seeds, and the software used. These results identify the best approaches to structure a DCE. An investigator can manipulate design characteristics to help reduce response burden and increase statistical efficiency. Since studies varied in their objectives, conclusions were made on several design characteristics, however, the validity of each conclusion was limited. Further research should be conducted to explore all conclusions in various design settings and scenarios. Additional reviews to explore other statistical efficiency outcomes and databases can also be performed to enhance the conclusions identified from this review.

Investigation of Multicultural Education Courses: The Case of Georgia State University

ERIC Educational Resources Information Center

Basbay, Alper

2014-01-01

Multicultural education includes the design of learning environments according to different cultural characteristics and learners' respectful attitudes towards these characteristics. One of the teachers' expected competencies in multicultural education is recognizing learners' cultural characteristics and being respectful of these during the…

A review of hospital characteristics associated with improved performance.

PubMed

Brand, Caroline A; Barker, Anna L; Morello, Renata T; Vitale, Michael R; Evans, Sue M; Scott, Ian A; Stoelwinder, Johannes U; Cameron, Peter A

2012-10-01

The objective of this review was to critically appraise the literature relating to associations between high-level structural and operational hospital characteristics and improved performance. The Cochrane Library, MEDLINE (Ovid), CINAHL, proQuest and PsychINFO were searched for articles published between January 1996 and May 2010. Reference lists of included articles were reviewed and key journals were hand searched for relevant articles. and data extraction Studies were included if they were systematic reviews or meta-analyses, randomized controlled trials, controlled before and after studies or observational studies (cohort and cross-sectional) that were multicentre, comparative performance studies. Two reviewers independently extracted data, assigned grades of evidence according to the Australian National Health and Medical Research Council guidelines and critically appraised the included articles. Data synthesis Fifty-seven studies were reported within 12 systematic reviews and 47 observational articles. There was heterogeneity in use and definition of performance outcomes. Hospital characteristics investigated were environment (incentives, market characteristics), structure (network membership, ownership, teaching status, geographical setting, service size) and operational design (innovativeness, leadership, organizational culture, public reporting and patient safety practices, information technology systems and decision support, service activity and planning, workforce design, staff training and education). The strongest evidence for an association with overall performance was identified for computerized physician order entry systems. Some evidence supported the associations with workforce design, use of financial incentives, nursing leadership and hospital volume. There is limited, mainly low-quality evidence, supporting the associations between hospital characteristics and healthcare performance. Further characteristic-specific systematic reviews are indicated.

Design of hybrid laser structures with QD-RSOA and silicon photonic mirrors

NASA Astrophysics Data System (ADS)

Gioannini, Mariangela; Benedetti, Alessio; Bardella, Paolo; Bovington, Jock; Traverso, Matt; Siriani, Dominic; Gothoskar, Prakash

2018-02-01

We compare the design of three different single mode laser structures consisting in a Reflective Semiconductor Optical Amplifier coupled to a silicon photonic external cavity mirror. The three designs differ for the mirror structure and are compared in terms of SOA power consumption and side mode suppression ratio (SMSR). Assuming then a Quantum Dot active material, we simulate the best laser design using a numerical model that includes the peculiar physical characteristics of the QD gain medium. The simulated QD laser CW characteristics are shown and discussed.

Analysis of design characteristics of a V-type support using an advanced engineering environment

NASA Astrophysics Data System (ADS)

Gwiazda, A.; Banaś, W.; Sękala, A.; Cwikla, G.; Topolska, S.; Foit, K.; Monica, Z.

2017-08-01

Modern mining support, for the entire period of their use, is the important part of the mining complex, which includes all the devices in the excavation during his normal use. Therefore, during the design of the support, it is an important task to choose the shape and to select the dimensions of a support as well as its strength characteristics. According to the rules, the design process of a support must take into account, inter alia, the type and the dimensions of the expected means of transport, the number and size of pipelines, and the type of additional equipment used excavation area. The support design must ensure the functionality of the excavation process and job security, while maintaining the economic viability of the entire project. Among others it should ensure the selection of a support for specific natural conditions. It is also important to take into consideration the economic characteristics of the project. The article presents an algorithm of integrative approach and its formalized description in the form of integration the areas of different construction characteristics optimization of a V-type mining support. The paper includes the example of its application for developing the construction of this support. In the paper is also described the results of the characteristics analysis and changings that were introduced afterwards. The support models are prepared in the computer environment of the CAD class (Siemens NX PLM). Also the analyses were conducted in this design, graphical environment.

Consumer perceptions of specific design characteristics for front-of-package nutrition labels.

PubMed

Acton, R B; Vanderlee, L; Roberto, C A; Hammond, D

2018-04-01

An increasing number of countries are developing front-of-package (FOP) labels; however, there is limited evidence examining the impact of specific design characteristics for these labels. The current study investigated consumer perceptions of several FOP label design characteristics, including potential differences among sociodemographic sub-groups. Two hundred and thirty-four participants aged 16 years or older completed nine label rating tasks on a laptop at a local shopping mall in Canada. The rating tasks asked participants to rate five primary design characteristics (border, background presence, background colour, 'caution' symbol and government attribution) on their noticeability, readability, believability and likelihood of changing their beverage choice. FOP labels with a border, solid background and contrasting colours increased noticeability. A solid background increased readability, while a contrasting background colour reduced it. Both a 'caution' symbol and a government attribution increased the believability of the labels and the perceived likelihood of influencing beverage choice. The effect of the design characteristics was generally similar across sociodemographic groups, with modest differences in five of the nine outcomes. Label design characteristics, such as the use of a border, colour and symbols can enhance the salience of FOP nutrition labels and may increase the likelihood that FOP labels are used by consumers.

Human body as a set of biometric features identified by means of optoelectronics

NASA Astrophysics Data System (ADS)

Podbielska, Halina; Bauer, Joanna

2005-09-01

Human body posses many unique, singular features that are impossible to copy or forge. Nowadays, to establish and to ensure the public security requires specially designed devices and systems. Biometrics is a field of science and technology, exploiting human body characteristics for people recognition. It identifies the most characteristic and unique ones in order to design and construct systems capable to recognize people. In this paper some overview is given, presenting the achievements in biometrics. The verification and identification process is explained, along with the way of evaluation of biometric recognition systems. The most frequently human biometrics used in practice are shortly presented, including fingerprints, facial imaging (including thermal characteristic), hand geometry and iris patterns.

10 CFR 55.41 - Written examination: Operators.

Code of Federal Regulations, 2011 CFR

2011-01-01

... coefficients, and poison effects. (2) General design features of the core, including core structure, fuel elements, control rods, core instrumentation, and coolant flow. (3) Mechanical components and design... changes, and operating limitations and reasons for these operating characteristics. (6) Design, components...

10 CFR 55.41 - Written examination: Operators.

Code of Federal Regulations, 2010 CFR

2010-01-01

... coefficients, and poison effects. (2) General design features of the core, including core structure, fuel elements, control rods, core instrumentation, and coolant flow. (3) Mechanical components and design... changes, and operating limitations and reasons for these operating characteristics. (6) Design, components...

10 CFR 55.41 - Written examination: Operators.

Code of Federal Regulations, 2012 CFR

2012-01-01

... coefficients, and poison effects. (2) General design features of the core, including core structure, fuel elements, control rods, core instrumentation, and coolant flow. (3) Mechanical components and design... changes, and operating limitations and reasons for these operating characteristics. (6) Design, components...

Discharge characteristics of 300 ampere-hour Ni-Zn traction cells

NASA Technical Reports Server (NTRS)

Ewashinka, J. G.

1979-01-01

Preliminary tests were performed on 300 amphere-hour nickel-zinc cells containing the Lewis improved inorganic-organic (I/O) separator. These cells also have other design features included to optimize performance and cycle life. The tests carried out were formation tests and characteristic discharge tests. Information obtained include case temperature and maximum power delivered.

Effect of wing design on the longitudinal aerodynamic characteristics of a wing-body model at subsonic speeds

NASA Technical Reports Server (NTRS)

Henderson, W. P.; Huffman, J. K.

1972-01-01

An investigation has been conducted to determine the effects of wing camber and twist on the longitudinal aerodynamic characteristics of a wingbody configuration. Three wings were used each having the same planform (aspect ratio of 2.5 and leading-edge sweep angle of 44 deg.) but differing in amounts of camber and twist (wing design lift coefficient). The wing design lift coefficients were 0, 0.35, and 0.70. The investigation was conducted over a Mach number range from 0.20 to 0.70 at angles of attack up to about 22 deg. The effect of wing strakes on the aerodynamic characteristics of the cambered wings was also studied. A comparison of the experimentally determined aerodynamic characteristics with theoretical estimates is also included.

Transonic Flow Computations Using Nonlinear Potential Methods

NASA Technical Reports Server (NTRS)

Holst, Terry L.; Kwak, Dochan (Technical Monitor)

2000-01-01

This presentation describes the state of transonic flow simulation using nonlinear potential methods for external aerodynamic applications. The presentation begins with a review of the various potential equation forms (with emphasis on the full potential equation) and includes a discussion of pertinent mathematical characteristics and all derivation assumptions. Impact of the derivation assumptions on simulation accuracy, especially with respect to shock wave capture, is discussed. Key characteristics of all numerical algorithm types used for solving nonlinear potential equations, including steady, unsteady, space marching, and design methods, are described. Both spatial discretization and iteration scheme characteristics are examined. Numerical results for various aerodynamic applications are included throughout the presentation to highlight key discussion points. The presentation ends with concluding remarks and recommendations for future work. Overall. nonlinear potential solvers are efficient, highly developed and routinely used in the aerodynamic design environment for cruise conditions. Published by Elsevier Science Ltd. All rights reserved.

Large space deployable antenna systems

NASA Technical Reports Server (NTRS)

1978-01-01

The design technology is described for manufacturing a 20 m or larger space erectable antenna with high thermal stability, high dynamic stiffness, and minimum stowed size. The selected approach includes a wrap rib design with a cantilever beam basic element and graphite-epoxy composite lenticular cross section ribs. The rib configuration and powered type operated deploying mechanism are described and illustrated. Other features of the parabolic reflector discussed include weight and stowed diameter characteristics, structural dynamics characteristics, orbit thermal aperture limitations, and equivalent element and secondary (on axis) patterns. A block diagram of the multiple beam pattern is also presented.

Design and validation of general biology learning program based on scientific inquiry skills

NASA Astrophysics Data System (ADS)

Cahyani, R.; Mardiana, D.; Noviantoro, N.

2018-03-01

Scientific inquiry is highly recommended to teach science. The reality in the schools and colleges is that many educators still have not implemented inquiry learning because of their lack of understanding. The study aims to1) analyze students’ difficulties in learning General Biology, 2) design General Biology learning program based on multimedia-assisted scientific inquiry learning, and 3) validate the proposed design. The method used was Research and Development. The subjects of the study were 27 pre-service students of general elementary school/Islamic elementary schools. The workflow of program design includes identifying learning difficulties of General Biology, designing course programs, and designing instruments and assessment rubrics. The program design is made for four lecture sessions. Validation of all learning tools were performed by expert judge. The results showed that: 1) there are some problems identified in General Biology lectures; 2) the designed products include learning programs, multimedia characteristics, worksheet characteristics, and, scientific attitudes; and 3) expert validation shows that all program designs are valid and can be used with minor revisions. The first section in your paper.

Preliminary design studies of an advanced general aviation aircraft

NASA Technical Reports Server (NTRS)

Barrett, Ron; Demoss, Shane; Dirkzwager, AB; Evans, Darryl; Gomer, Charles; Keiter, Jerry; Knipp, Darren; Seier, Glen; Smith, Steve; Wenninger, ED

1991-01-01

The preliminary design results are presented of the advanced aircraft design project. The goal was to take a revolutionary look into the design of a general aviation aircraft. Phase 1 of the project included the preliminary design of two configurations, a pusher, and a tractor. Phase 2 included the selection of only one configuration for further study. The pusher configuration was selected on the basis of performance characteristics, cabin noise, natural laminar flow, and system layouts. The design was then iterated to achieve higher levels of performance.

An optimized implementation of a fault-tolerant clock synchronization circuit

NASA Technical Reports Server (NTRS)

Torres-Pomales, Wilfredo

1995-01-01

A fault-tolerant clock synchronization circuit was designed and tested. A comparison to a previous design and the procedure followed to achieve the current optimization are included. The report also includes a description of the system and the results of tests performed to study the synchronization and fault-tolerant characteristics of the implementation.

Assessing performance characteristics of sediment basins constructed in Franklin County.

DOT National Transportation Integrated Search

2012-08-01

The objective of the research project was to monitor the performance of newly designed : sediment basins that were constructed on the ALDOT 502 project in Franklin County. The : project included four tasks: (1) assess performance characteristics of s...

Results from conceptual design study of potential early commercial MHD/steam power plants

NASA Technical Reports Server (NTRS)

Hals, F.; Kessler, R.; Swallom, D.; Westra, L.; Zar, J.; Morgan, W.; Bozzuto, C.

1981-01-01

This paper presents conceptual design information for a potential early MHD power plant developed in the second phase of a joint study of such plants. Conceptual designs of plant components and equipment with performance, operational characteristics and costs are reported on. Plant economics and overall performance including full and part load operation are reviewed. Environmental aspects and the methods incorporated in plant design for emission control of sulfur and nitrogen oxides are reviewed. Results from reliability/availability analysis conducted are also included.

Habitability design elements for a space station

NASA Technical Reports Server (NTRS)

Dalton, M. C.

1983-01-01

Habitability in space refers to the components, characteristics, conditions, and design parameters that go beyond but include the basic life sustaining requirements. Elements of habitability covered include internal environment, architecture, mobility and restraint, food, clothing, personal hygiene, housekeeping, communications, and crew activities. All elements are interrelated and need to be treated as an overall discipline. Designing for a space station is similar to designing on earth but with 'space rules' instead of ground rules. It is concluded that some habitability problems require behavioral science solutions.

Young Tanzanians and the Cinema: A Study of the Effects of Selected Basic Motion Picture Elements and Population Characteristics on Filmic Comprehension of Tanzanian Adolescent Primary School Children.

ERIC Educational Resources Information Center

Giltrow, David Roger

A study was conducted of Tanzanian adolescent school children's responses to filmic elements. The design included a very large sample in a complicated factorial design, varying such factors as color, type of action, background and sound of the film, and the demographic characteristics of the subjects. Results showed that of these variables,…

Vehicle operation characteristic under different ramp entrance conditions in underground road: Analysis, simulation and modelling

NASA Astrophysics Data System (ADS)

Yao, Qiming; Liu, Shuo; Liu, Yang

2018-05-01

An experimental design was used to study the vehicle operation characteristics of different ramp entrance conditions in underground road. With driving simulator, the experimental scenarios include left or right ramp with first, second and third service level, respectively, to collect vehicle speed, acceleration, lateral displacement and location information at the ramp entrance section. By using paired t-test and ANOVA, the influence factors of vehicle operating characteristics are studied. The result shows that effects of ramp layout and mainline traffic environment on vehicle operation characteristics are significant. The regression model of vehicle traveling distance on acceleration lane is established. Suggestions are made for ramp entrance design of underground road.

Developing a 3D Game Design Authoring Package to Assist Students' Visualization Process in Design Thinking

ERIC Educational Resources Information Center

Kuo, Ming-Shiou; Chuang, Tsung-Yen

2013-01-01

The teaching of 3D digital game design requires the development of students' meta-skills, from story creativity to 3D model construction, and even the visualization process in design thinking. The characteristics a good game designer should possess have been identified as including redesign things, creativity thinking and the ability to…

Research design features and patient characteristics associated with the outcome of antidepressant clinical trials.

PubMed

Khan, Arif; Kolts, Russell L; Thase, Michael E; Krishnan, K Ranga Rama; Brown, Walter

2004-11-01

The authors examined which, if any, research design features and patient characteristics would significantly differ between successful and unsuccessful antidepressant trials. Clinical trial data were reviewed for nine antidepressants approved by the Food and Drug Administration between 1985 and 2000. From the antidepressant research programs on these medications, 52 clinical trials were included in the study. The authors evaluated trial design features, patient characteristics, and difference in response between placebo and antidepressant. Nine trial design features and patient characteristics were present in the research programs for all nine of the antidepressants. The severity of depressive symptoms before patient randomization, the dosing schedule (flexible versus fixed), the number of treatment arms, and the percentage of female patients were significantly associated with the difference in response to antidepressant and placebo. The duration of the antidepressant trial, number of patients per treatment arm, number of sites, and mean age of the patients were similar in successful trials (with a greater antidepressant-placebo difference) and less successful trials (with a smaller antidepressant-placebo difference). These findings may help in the design of future antidepressant trials.

An Analytical Design Method for a Regenerative Braking Control System for DC-electrified Railway Systems under Light Load Conditions

NASA Astrophysics Data System (ADS)

Saito, Tatsuhito; Kondo, Keiichiro; Koseki, Takafumi

A DC-electrified railway system that is fed by diode rectifiers at a substation is unable to return the electric power to an AC grid. Accordingly, the braking cars have to restrict regenerative braking power when the power consumption of the powering cars is not sufficient. However, the characteristics of a DC-electrified railway system, including the powering cars, is not known, and a mathematical model for designing a controller has not been established yet. Hence, the object of this study is to obtain the mathematical model for an analytical design method of the regenerative braking control system. In the first part of this paper, the static characteristics of this system are presented to show the position of the equilibrium point. The linearization of this system at the equilibrium point is then performed to describe the dynamic characteristics of the system. An analytical design method is then proposed on the basis of these characteristics. The proposed design method is verified by experimental tests with a 1kW class miniature model, and numerical simulations.

Multivariate Analysis, Retrieval, and Storage System (MARS). Volume 1: MARS System and Analysis Techniques

NASA Technical Reports Server (NTRS)

Hague, D. S.; Vanderberg, J. D.; Woodbury, N. W.

1974-01-01

A method for rapidly examining the probable applicability of weight estimating formulae to a specific aerospace vehicle design is presented. The Multivariate Analysis Retrieval and Storage System (MARS) is comprised of three computer programs which sequentially operate on the weight and geometry characteristics of past aerospace vehicles designs. Weight and geometric characteristics are stored in a set of data bases which are fully computerized. Additional data bases are readily added to the MARS system and/or the existing data bases may be easily expanded to include additional vehicles or vehicle characteristics.

Extravehicular activities guidelines and design criteria

NASA Technical Reports Server (NTRS)

Brown, N. E.; Dashner, T. R.; Hayes, B. C.

1973-01-01

A listing of astronaut EVA support systems and equipment, and the physical, operational, and performance characteristics of each major system are presented. An overview of the major ground based support operations necessary in the development and verification of orbital EVA systems is included. The performance and biomedical characteristics of man in the orbital EV environment are discussed. Major factors affecting astronaut EV work performance are identified and delineated as they relate to EV support systems design. Data concerning the medical and physiological aspects of spaceflight on man are included. The document concludes with an extensive bibliography, and a series of appendices which expand on some of the information presented in the main body.

Improved Steam Turbine Leakage Control with a Brush Seal Design

NASA Astrophysics Data System (ADS)

Turnquist, Norman; Chupp, Raymond E.; Pastrana, Ryan; Wolfe, Chris; Burnett, Mark

2002-10-01

This paper presents an improved steam turbine leakage control system with a brush seal design. The contents include: 1) Typical Design Characteristics; 2) Typical Brush Seal Locations; 3) Reduced Leakage Rates; 4) Performance Benefits; 5) System Considerations; 6) Rotor Dynamics; 7) Laboratory Tests and 8) Field Experience.

Universal Design: Implications for Computing Education

ERIC Educational Resources Information Center

Burgstahler, Sheryl

2011-01-01

Universal design (UD), a concept that grew from the field of architecture, has recently emerged as a paradigm for designing instructional methods, curriculum, and assessments that are welcoming and accessible to students with a wide range of characteristics, including those related to race, ethnicity, native language, gender, age, and disability.…

Spinning characteristics of wings II : rectangular Clark Y biplane cellule: 25 percent stagger; 0 degree decalage; gap/chord 1.0

NASA Technical Reports Server (NTRS)

Bamber, M J

1935-01-01

General methods of theoretical analysis of airplane spinning characteristics have been available for some time. Some of these methods of analysis might be used by designers to predict the spinning characteristics of proposed airplane designs if the necessary aerodynamic data were known. The present investigation, to determine the spinning characteristics of wings, is planned to include variations in airfoil sections, plan forms, and tip shapes of monoplane wings and variations in stagger, gap, and decalage for biplane cellules. The first series of tests, made on a rectangular Clark Y monoplane wing, are reported in reference 1. That report also gives an analysis of the data for predicting the probable effects of various important parameters on the spin for normal airplanes using such a wing. The present report is the second of the series. It gives the aerodynamic characteristics of a rectangular Clark Y biplane cellule in spinning attitudes and includes a discussion of the data, using the method of analysis given in reference 1.

Hydraulic Characteristics Of Two Bicycle-Safe Grate Inlet Designs

DOT National Transportation Integrated Search

1988-12-01

Expert Systems are computer programs designed to include a simulation of the reasoning and decision-making processes of human experts. This report provides a set of general guidelines for the development and distribution of highway related expert sys...

Urban Design, Urban Form, And Employee Travel Behavior

DOT National Transportation Integrated Search

1997-01-01

Personal travel behavior choices made by employees appear to be influenced by a number of urban design and urban form characteristics of their work place. Several important attributes include the density of development and the accessibility of non-wo...

Improving of technical characteristics of launch vehicles with liquid rocket engines using active onboard de-orbiting systems

NASA Astrophysics Data System (ADS)

Trushlyakov, V.; Shatrov, Ya.

2017-09-01

In this paper, the analysis of technical requirements (TR) for the development of modern space launch vehicles (LV) with main liquid rocket engines (LRE) is fulfilled in relation to the anthropogenic impact decreasing. Factual technical characteristics on the example of a promising type of rocket ;Soyuz-2.1.v.; are analyzed. Meeting the TR in relation to anthropogenic impact decrease based on the conventional design approach and the content of the onboard system does not prove to be efficient and leads to depreciation of the initial technical characteristics obtained at the first design stage if these requirements are not included. In this concern, it is shown that the implementation of additional active onboard de-orbiting system (AODS) of worked-off stages (WS) into the onboard LV stages systems allows to meet the TR related to the LV environmental characteristics, including fire-explosion safety. In some cases, the orbital payload mass increases.

Parental and Child Characteristics Related to Early-Onset Disordered Eating: A Systematic Review.

PubMed

Larsen, Pernille Stemann; Strandberg-Larsen, Katrine; Micali, Nadia; Andersen, Anne-Marie Nybo

2015-01-01

After participating in this activity, learners should be better able to: Evaluate the evidence regarding parental and child characteristics related to early-onset disordered eating. Eating disorders are rare in children, but disordered eating is common. Understanding the phenomenology of disordered eating in childhood can aid prevention of full-blown eating disorders. The purpose of this review is to systematically extract and synthesize the evidence on parental and child characteristics related to early-onset disordered eating. Systematic searches were conducted in PubMED/MEDLINE, EMBASE, and PsycInfo using the following search terms: eating disorder, disordered eating, problem eating, anorexia nervosa, bulimia nervosa, binge eating, child, preadolescent, and early onset. Studies published from 1990 to 2013 addressing parental and child characteristics of disordered eating in children aged 6 to 12 years were eligible for inclusion. The search was restricted to studies with cross-sectional, case-control, or longitudinal designs, studies in English, and with abstracts available. Forty-four studies fit these criteria. Most studies were based on community samples with a cross-sectional design. The included studies varied considerably in size, instruments used to assess early-onset disordered eating, and parental and child characteristics investigated. Important determinants included the following: higher body weight, previously reported disordered eating, body dissatisfaction, depression, parental disordered eating, and parental comments/concerns about child's weight and eating. The findings were inconsistent for sex, age, socioeconomic status, ethnicity, self-esteem/worth, and parental body weight. In conclusion, characteristics related to early-onset disordered eating have mainly been explored with a cross-sectional design. Full understanding of causal pathways will require good-quality longitudinal studies designed to address the influence of parental eating behaviors, mental and physical health, family interactions, and child growth patterns.

RF-MEMS Technology for High-Performance Passives; The challenge of 5G mobile applications

NASA Astrophysics Data System (ADS)

Iannacci, Jacopo

2017-11-01

Commencing with a review of the characteristics of RF-MEMS in relation to 5G, the book proceeds to develop practical insight concerning the design and development of RF-MEMS including case studies of design concepts. Including multiphysics simulation and animated figures, the book will be essential reading for both academic and industrial researchers and engineers.

Lithium D-cell study

NASA Technical Reports Server (NTRS)

Size, P.; Takeuchi, Esther S.

1993-01-01

The purpose of this contract is to evaluate parametrically the effects of various factors including the electrolyte type, electrolyte concentration, depolarizer type, and cell configuration on lithium cell electrical performance and safety. This effort shall allow for the selection and optimization of cell design for future NASA applications while maintaining close ties with WGL's continuous improvements in manufacturing processes and lithium cell design. Taguchi experimental design techniques are employed in this task, and allow for a maximum amount of information to be obtained while requiring significantly less cells than if a full factorial design were employed. Acceptance testing for this task is modeled after the NASA Document EP5-83-025, Revision C, for cell weights, OCV's and load voltages. The performance attributes that are studied in this effort are fresh capacity and start-up characteristics evaluated at two rates and two temperatures, shelf-life characteristics including start-up and capacity retention, and iterative microcalorimetry measurements. Abuse testing includes forced over discharge at two rates with and without diode protection, temperature tolerance testing, and shorting tests at three rates with the measurement of heat generated during shorting conditions.

Introduction to Psychology and Leadership. Typological Analysis of Student Characteristics: Preliminary Report.

ERIC Educational Resources Information Center

Bessemer, David W.; Shrage, Jules H.

Recommendations for an alternative plan, based on typological analysis techniques, for the evaluation of student characteristics related to media, presentation design, and academic performance are presented. Difficulties with present evaluation plans are discussed, and different methods of typological analysis are described. Included are…

Optimal control theory investigation of proprotor/wing response to vertical gust

NASA Technical Reports Server (NTRS)

Frick, J. K. D.; Johnson, W.

1974-01-01

Optimal control theory is used to design linear state variable feedback to improve the dynamic characteristics of a rotor and cantilever wing representing the tilting proprotor aircraft in cruise flight. The response to a vertical gust and system damping are used as criteria for the open and closed loop performance. The improvement in the dynamic characteristics achievable is examined for a gimballed rotor and for a hingeless rotor design. Several features of the design process are examined, including: (1) using only the wing or only the rotor dynamics in the control system design; (2) the use of a wing flap as well as the rotor controls for inputs; (3) and the performance of the system designed for one velocity at other forward speeds.

Application of the CSCM method to the design of wedge cavities. [Conservative Supra Characteristic Method

NASA Technical Reports Server (NTRS)

Venkatapathy, Ethiraj; Nystrom, G. A.; Bardina, J.; Lombard, C. K.

1987-01-01

This paper describes the application of the conservative supra characteristic method (CSCM) to predict the flow around two-dimensional slot injection cooled cavities in hypersonic flow. Seven different numerical solutions are presented that model three different experimental designs. The calculations manifest outer flow conditions including the effects of nozzle/lip geometry, angle of attack, nozzle inlet conditions, boundary and shear layer growth and turbulance on the surrounding flow. The calculations were performed for analysis prior to wind tunnel testing for sensitivity studies early in the design process. Qualitative and quantitative understanding of the flows for each of the cavity designs and design recommendations are provided. The present paper demonstrates the ability of numerical schemes, such as the CSCM method, to play a significant role in the design process.

76 FR 75735 - Certification of Part 23 Turbofan- and Turbojet-Powered Airplanes and Miscellaneous Amendments

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-02

... airplanes in air commerce by prescribing minimum standards required in the interest of safety for the design... prescribes new safety standards for the design of normal, utility, acrobatic, and commuter category airplanes... Category To Include Turbojets C. Performance, Flight Characteristics, and Other Design Considerations D...

Methodological characteristics and treatment effect sizes in oral health randomised controlled trials: Is there a relationship? Protocol for a meta-epidemiological study.

PubMed

Saltaji, Humam; Armijo-Olivo, Susan; Cummings, Greta G; Amin, Maryam; Flores-Mir, Carlos

2014-02-25

It is fundamental that randomised controlled trials (RCTs) are properly conducted in order to reach well-supported conclusions. However, there is emerging evidence that RCTs are subject to biases which can overestimate or underestimate the true treatment effect, due to flaws in the study design characteristics of such trials. The extent to which this holds true in oral health RCTs, which have some unique design characteristics compared to RCTs in other health fields, is unclear. As such, we aim to examine the empirical evidence quantifying the extent of bias associated with methodological and non-methodological characteristics in oral health RCTs. We plan to perform a meta-epidemiological study, where a sample size of 60 meta-analyses (MAs) including approximately 600 RCTs will be selected. The MAs will be randomly obtained from the Oral Health Database of Systematic Reviews using a random number table; and will be considered for inclusion if they include a minimum of five RCTs, and examine a therapeutic intervention related to one of the recognised dental specialties. RCTs identified in selected MAs will be subsequently included if their study design includes a comparison between an intervention group and a placebo group or another intervention group. Data will be extracted from selected trials included in MAs based on a number of methodological and non-methodological characteristics. Moreover, the risk of bias will be assessed using the Cochrane Risk of Bias tool. Effect size estimates and measures of variability for the main outcome will be extracted from each RCT included in selected MAs, and a two-level analysis will be conducted using a meta-meta-analytic approach with a random effects model to allow for intra-MA and inter-MA heterogeneity. The intended audiences of the findings will include dental clinicians, oral health researchers, policymakers and graduate students. The aforementioned will be introduced to the findings through workshops, seminars, round table discussions and targeted individual meetings. Other opportunities for knowledge transfer will be pursued such as key dental conferences. Finally, the results will be published as a scientific report in a dental peer-reviewed journal.

ATLAS, an integrated structural analysis and design system. Volume 6: Design module theory

NASA Technical Reports Server (NTRS)

Backman, B. F.

1979-01-01

The automated design theory underlying the operation of the ATLAS Design Module is decribed. The methods, applications and limitations associated with the fully stressed design, the thermal fully stressed design and a regional optimization algorithm are presented. A discussion of the convergence characteristics of the fully stressed design is also included. Derivations and concepts specific to the ATLAS design theory are shown, while conventional terminology and established methods are identified by references.

Effect of external jet-flow deflector geometry on OTW aero-acoustic characteristics

NASA Technical Reports Server (NTRS)

Vonglahn, U.; Groesbeck, D.

1976-01-01

The effect of geometry variations in the design of external deflectors for use with over-the-wing (OTW) configurations was studied at model scale and subsonic jet velocities. Included in the variations were deflector size and angle as well as wing size and flap setting. A conical nozzle (5.2-cm diameter) mounted at 0.1 chord above and downstream of the wing leading edges was used. The data indicate that external deflectors provide satisfactory takeoff and approach aerodynamic performance and acoustic characteristics for OTW configurations. These characteristics together with expected good cruise aerodynamics, since external deflectors are storable, may provide optimum OTW design configurations.

Engineering design manual of parachute decelerator characteristics for space shuttle solid rocket booster recovery

NASA Technical Reports Server (NTRS)

Mansfield, D. L.

1973-01-01

The design criteria and characteristics of parachutes for recovery of the solid rocket boosters used with the space shuttle launch are presented. A computer program for analyzing the requirements of the parachute decelerators is described. The computer inputs for both the drogue and main parachute decelerators are; (1) parachute size, (2) deployment conditions, (3) inflation times, (4) reefing times, (5) mass properties, (6) spring properties, and (7) aerodynamic coefficients. Graphs of the parachute performance are included.

Adaptable structural synthesis using advanced analysis and optimization coupled by a computer operating system

NASA Technical Reports Server (NTRS)

Sobieszczanski-Sobieski, J.; Bhat, R. B.

1979-01-01

A finite element program is linked with a general purpose optimization program in a 'programing system' which includes user supplied codes that contain problem dependent formulations of the design variables, objective function and constraints. The result is a system adaptable to a wide spectrum of structural optimization problems. In a sample of numerical examples, the design variables are the cross-sectional dimensions and the parameters of overall shape geometry, constraints are applied to stresses, displacements, buckling and vibration characteristics, and structural mass is the objective function. Thin-walled, built-up structures and frameworks are included in the sample. Details of the system organization and characteristics of the component programs are given.

The New Generation: Characteristics and Motivations of BME Graduate Entrepreneurs

ERIC Educational Resources Information Center

Hussain, Javed G.; Scott, Jonathan M.; Hannon, Paul D.

2008-01-01

Purpose: The purpose of this paper is to profile the characteristics and entrepreneurial motivations of graduate entrepreneurs from black and minority ethnic (BME) communities. Design/methodology/approach: To gather the data, the authors interviewed selected individuals from within the BME community (including current students and graduates from…

Precision Attitude Determination System (PADS) design and analysis. Two-axis gimbal star tracker

NASA Technical Reports Server (NTRS)

1973-01-01

Development of the Precision Attitude Determination System (PADS) focused chiefly on the two-axis gimballed star tracker and electronics design improved from that of Precision Pointing Control System (PPCS), and application of the improved tracker for PADS at geosynchronous altitude. System design, system analysis, software design, and hardware design activities are reported. The system design encompasses the PADS configuration, system performance characteristics, component design summaries, and interface considerations. The PADS design and performance analysis includes error analysis, performance analysis via attitude determination simulation, and star tracker servo design analysis. The design of the star tracker and electronics are discussed. Sensor electronics schematics are included. A detailed characterization of the application software algorithms and computer requirements is provided.

The 5-kwe reactor thermoelectric system summary

NASA Technical Reports Server (NTRS)

Vanosdol, J. H. (Editor)

1973-01-01

Design of the 5-kwe reactor thermoelectric system was initiated in February 1972 and extended through the conceptual design phase into the preliminary design phase. Design effort was terminated in January, 1973. This report documents the system and component requirements, design approaches, and performance and design characteristics for the 5-kwe system. Included is summary information on the reactor, radiation shields, power conversion systems, thermoelectric pump, radiator/structure, liquid metal components, and the control system.

Some Implications of Cognitive Theory for Instructional Design.

ERIC Educational Resources Information Center

Winn, William

1990-01-01

Examines some of the recent developments in cognitive theory and explores their implications for instructional design. Topics discussed include a shift from emphasis on behavioral theory to cognitive theory; task analysis; instructional objectives; learner characteristics; instructional strategies; metacognition; and the dynamic nature of…

Housing, Design, and Furnishings.

ERIC Educational Resources Information Center

Texas Tech Univ., Lubbock. Home Economics Curriculum Center.

This document contains teacher's materials for a six-unit secondary education vocational home economics course on housing, design, and furnishings. The units cover: (1) the societal aspects of housing (including the relationship between housing and the economy, population trends, and culture-related housing characteristics); (2) family housing…

Global Sentry: NASA/USRA high altitude reconnaissance aircraft design, volume 2

NASA Technical Reports Server (NTRS)

Alexandru, Mona-Lisa; Martinez, Frank; Tsou, Jim; Do, Henry; Peters, Ashish; Chatsworth, Tom; Yu, YE; Dhillon, Jaskiran

1990-01-01

The Global Sentry is a high altitude reconnaissance aircraft design for the NASA/USRA design project. The Global Sentry uses proven technologies, light-weight composites, and meets the R.F.P. requirements. The mission requirements for the Global Sentry are described. The configuration option is discussed and a description of the final design is given. Preliminary sizing analyses and the mass properties of the design are presented. The aerodynamic features of the Global Sentry are described along with the stability and control characteristics designed into the flight control system. The performance characteristics are discussed as is the propulsion installation and system layout. The Global Sentry structural design is examined, including a wing structural analysis. The cockpit, controls and display layouts are covered. Manufacturing is covered and the life cost estimation. Reliability is discussed. Conclusions about the current Global Sentry design are presented, along with suggested areas for future engineering work.

Parametric Study and Design of Tab Shape for Improving Aerodynamic Performance of Rotor Blade

NASA Astrophysics Data System (ADS)

Han, Jaeseong; Kwon, Oh Joon

2018-04-01

In the present study, the parametric study was performed to analyze the effect of the tab on the aerodynamic performance and characteristics of rotor blades. Also, the tab shape was designed to improve the aerodynamic performance of rotor blades. A computational fluid dynamics solver based on three-dimensional Reynolds averaged Navier-Stokes equation using an unstructured mesh was used for the parametric study and the tab design. For airfoils, the effect of length and angle of a tab was studied on the aerodynamic characteristics of airfoils. In addition, including those parameters, the effect of a span of a tab was studied for rotor blades in hovering flight. The results of the parametric study were analyzed in terms of change of the aerodynamic performance and characteristics to understand the effect of a tab. Considering the analysis, the design of tab shape was conducted to improve the aerodynamic performance of rotor blades. The simply attached tab to trailing edge of the rotor blades increases the thrust of the rotor blades without significant changing of aerodynamic characteristics of the rotor blades in hovering and forward flight.

Using Finite Element and Eigenmode Expansion Methods to Investigate the Periodic and Spectral Characteristic of Superstructure Fiber Bragg Gratings

PubMed Central

He, Yue-Jing; Hung, Wei-Chih; Lai, Zhe-Ping

2016-01-01

In this study, a numerical simulation method was employed to investigate and analyze superstructure fiber Bragg gratings (SFBGs) with five duty cycles (50%, 33.33%, 14.28%, 12.5%, and 10%). This study focuses on demonstrating the relevance between design period and spectral characteristics of SFBGs (in the form of graphics) for SFBGs of all duty cycles. Compared with complicated and hard-to-learn conventional coupled-mode theory, the result of the present study may assist beginner and expert designers in understanding the basic application aspects, optical characteristics, and design techniques of SFBGs, thereby indirectly lowering the physical concepts and mathematical skills required for entering the design field. To effectively improve the accuracy of overall computational performance and numerical calculations and to shorten the gap between simulation results and actual production, this study integrated a perfectly matched layer (PML), perfectly reflecting boundary (PRB), object meshing method (OMM), and boundary meshing method (BMM) into the finite element method (FEM) and eigenmode expansion method (EEM). The integrated method enables designers to easily and flexibly design optical fiber communication systems that conform to the specific spectral characteristic by using the simulation data in this paper, which includes bandwidth, number of channels, and band gap size. PMID:26861322

Space telescope optical telescope assembly/scientific instruments. Phase B: -Preliminary design and program definition study; Volume 2A: Planetary camera report

NASA Technical Reports Server (NTRS)

1976-01-01

Development of the F/48, F/96 Planetary Camera for the Large Space Telescope is discussed. Instrument characteristics, optical design, and CCD camera submodule thermal design are considered along with structural subsystem and thermal control subsystem. Weight, electrical subsystem, and support equipment requirements are also included.

Design of prototype charged particle fog dispersal unit

NASA Technical Reports Server (NTRS)

Collins, F. G.; Frost, W.; Kessel, P.

1981-01-01

The unit was designed to be easily modified so that certain features that influence the output current and particle size distribution could be examined. An experimental program was designed to measure the performance of the unit. The program described includes measurements in a fog chamber and in the field. Features of the nozzle and estimated nozzle characteristics are presented.

A phase II flexible screening design allowing for interim analysis and comparison with historical control.

PubMed

Wu, Wenting; Bot, Brian; Hu, Yan; Geyer, Susan M; Sargent, Daniel J

2013-07-01

Sargent and Goldberg [1] proposed a randomized phase II flexible screening design (SG design) which took multiple characteristics of candidate regimens into consideration in selecting a regimen for further phase III testing. In this paper, we extend the SG design by including provisions for an interim analysis and/or a comparison to a historical control. By including a comparison with a historical control, a modified SG design not only identifies a more promising treatment but also assures that the regimen has a clinically meaningful level of efficacy as compared to a historical control. By including an interim analysis, a modified SG design could reduce the number of patients exposed to inferior treatment regimens. When compared to the original SG design, the modified designs increase the sample size moderately, but expand the utility of the flexible screening design substantially. Copyright © 2013 Elsevier Inc. All rights reserved.

Characterization of truck traffic in Michigan for the new mechanistic empirical pavement design guide.

DOT National Transportation Integrated Search

2009-12-01

The purpose of this study is to characterize traffic inputs in support of the new Mechanistic- : Empirical Pavement Design Guide (M-E PDG) for the state of Michigan. These traffic : characteristics include monthly distribution factors (MDF), hourly d...

Orbit Transfer Vehicle (OTV) advanced expander cycle engine point design study, volume 2

NASA Technical Reports Server (NTRS)

1981-01-01

The engine requirements are emphasized and include: high specific impulse within a restricted installed length constraint, long life, multiple starts, different thrust levels, and man-rated reliability. The engine operating characteristics and the major component analytical design are summarized.

45 CFR 287.130 - Can NEW Program activities include job market assessments, job creation and economic development...

Code of Federal Regulations, 2011 CFR

2011-10-01

... Program Design and Operations § 287.130 Can NEW Program activities include job market assessments, job...-sufficiency of program participants; (6) Surveys to collect information regarding client characteristics; and...

45 CFR 287.130 - Can NEW Program activities include job market assessments, job creation and economic development...

Code of Federal Regulations, 2014 CFR

2014-10-01

... Program Design and Operations § 287.130 Can NEW Program activities include job market assessments, job...-sufficiency of program participants; (6) Surveys to collect information regarding client characteristics; and...

Ergonomics for Online Searching.

ERIC Educational Resources Information Center

Wright, Carol; Friend, Linda

1992-01-01

Describes factors to be considered in the design of ergonomically correct workstations for online searchers. Topics discussed include visual factors, including lighting; acoustical factors; radiation and visual display terminals (VDTs); screen image characteristics; static electricity; hardware and equipment; workstation configuration; chairs;…

Design Characteristics Influence Performance of Clinical Prediction Rules in Validation: A Meta-Epidemiological Study

PubMed Central

Ban, Jong-Wook; Emparanza, José Ignacio; Urreta, Iratxe; Burls, Amanda

2016-01-01

Background Many new clinical prediction rules are derived and validated. But the design and reporting quality of clinical prediction research has been less than optimal. We aimed to assess whether design characteristics of validation studies were associated with the overestimation of clinical prediction rules’ performance. We also aimed to evaluate whether validation studies clearly reported important methodological characteristics. Methods Electronic databases were searched for systematic reviews of clinical prediction rule studies published between 2006 and 2010. Data were extracted from the eligible validation studies included in the systematic reviews. A meta-analytic meta-epidemiological approach was used to assess the influence of design characteristics on predictive performance. From each validation study, it was assessed whether 7 design and 7 reporting characteristics were properly described. Results A total of 287 validation studies of clinical prediction rule were collected from 15 systematic reviews (31 meta-analyses). Validation studies using case-control design produced a summary diagnostic odds ratio (DOR) 2.2 times (95% CI: 1.2–4.3) larger than validation studies using cohort design and unclear design. When differential verification was used, the summary DOR was overestimated by twofold (95% CI: 1.2 -3.1) compared to complete, partial and unclear verification. The summary RDOR of validation studies with inadequate sample size was 1.9 (95% CI: 1.2 -3.1) compared to studies with adequate sample size. Study site, reliability, and clinical prediction rule was adequately described in 10.1%, 9.4%, and 7.0% of validation studies respectively. Conclusion Validation studies with design shortcomings may overestimate the performance of clinical prediction rules. The quality of reporting among studies validating clinical prediction rules needs to be improved. PMID:26730980

Design Characteristics Influence Performance of Clinical Prediction Rules in Validation: A Meta-Epidemiological Study.

PubMed

Ban, Jong-Wook; Emparanza, José Ignacio; Urreta, Iratxe; Burls, Amanda

2016-01-01

Many new clinical prediction rules are derived and validated. But the design and reporting quality of clinical prediction research has been less than optimal. We aimed to assess whether design characteristics of validation studies were associated with the overestimation of clinical prediction rules' performance. We also aimed to evaluate whether validation studies clearly reported important methodological characteristics. Electronic databases were searched for systematic reviews of clinical prediction rule studies published between 2006 and 2010. Data were extracted from the eligible validation studies included in the systematic reviews. A meta-analytic meta-epidemiological approach was used to assess the influence of design characteristics on predictive performance. From each validation study, it was assessed whether 7 design and 7 reporting characteristics were properly described. A total of 287 validation studies of clinical prediction rule were collected from 15 systematic reviews (31 meta-analyses). Validation studies using case-control design produced a summary diagnostic odds ratio (DOR) 2.2 times (95% CI: 1.2-4.3) larger than validation studies using cohort design and unclear design. When differential verification was used, the summary DOR was overestimated by twofold (95% CI: 1.2 -3.1) compared to complete, partial and unclear verification. The summary RDOR of validation studies with inadequate sample size was 1.9 (95% CI: 1.2 -3.1) compared to studies with adequate sample size. Study site, reliability, and clinical prediction rule was adequately described in 10.1%, 9.4%, and 7.0% of validation studies respectively. Validation studies with design shortcomings may overestimate the performance of clinical prediction rules. The quality of reporting among studies validating clinical prediction rules needs to be improved.

A compendium of controlled diffusion blades generated by an automated inverse design procedure

NASA Technical Reports Server (NTRS)

Sanz, Jose M.

1989-01-01

A set of sample cases was produced to test an automated design procedure developed at the NASA Lewis Research Center for the design of controlled diffusion blades. The range of application of the automated design procedure is documented. The results presented include characteristic compressor and turbine blade sections produced with the automated design code as well as various other airfoils produced with the base design method prior to the incorporation of the automated procedure.

Perform - A performance optimizing computer program for dynamic systems subject to transient loadings

NASA Technical Reports Server (NTRS)

Pilkey, W. D.; Wang, B. P.; Yoo, Y.; Clark, B.

1973-01-01

A description and applications of a computer capability for determining the ultimate optimal behavior of a dynamically loaded structural-mechanical system are presented. This capability provides characteristics of the theoretically best, or limiting, design concept according to response criteria dictated by design requirements. Equations of motion of the system in first or second order form include incompletely specified elements whose characteristics are determined in the optimization of one or more performance indices subject to the response criteria in the form of constraints. The system is subject to deterministic transient inputs, and the computer capability is designed to operate with a large linear programming on-the-shelf software package which performs the desired optimization. The report contains user-oriented program documentation in engineering, problem-oriented form. Applications cover a wide variety of dynamics problems including those associated with such diverse configurations as a missile-silo system, impacting freight cars, and an aircraft ride control system.

Investigation of High-alpha Lateral-directional Control Power Requirements for High-performance Aircraft

NASA Technical Reports Server (NTRS)

Foster, John V.; Ross, Holly M.; Ashley, Patrick A.

1993-01-01

Designers of the next-generation fighter and attack airplanes are faced with the requirements of good high-angle-of-attack maneuverability as well as efficient high speed cruise capability with low radar cross section (RCS) characteristics. As a result, they are challenged with the task of making critical design trades to achieve the desired levels of maneuverability and performance. This task has highlighted the need for comprehensive, flight-validated lateral-directional control power design guidelines for high angles of attack. A joint NASA/U.S. Navy study has been initiated to address this need and to investigate the complex flight dynamics characteristics and controls requirements for high-angle-of-attack lateral-directional maneuvering. A multi-year research program is underway which includes ground-based piloted simulation and flight validation. This paper will give a status update of this program that will include a program overview, description of test methodology and preliminary results.

Investigation of high-alpha lateral-directional control power requirements for high-performance aircraft

NASA Technical Reports Server (NTRS)

Foster, John V.; Ross, Holly M.; Ashley, Patrick A.

1993-01-01

Designers of the next-generation fighter and attack airplanes are faced with the requirements of good high angle-of-attack maneuverability as well as efficient high speed cruise capability with low radar cross section (RCS) characteristics. As a result, they are challenged with the task of making critical design trades to achieve the desired levels of maneuverability and performance. This task has highlighted the need for comprehensive, flight-validated lateral-directional control power design guidelines for high angles of attack. A joint NASA/U.S. Navy study has been initiated to address this need and to investigate the complex flight dynamics characteristics and controls requirements for high angle-of-attack lateral-directional maneuvering. A multi-year research program is underway which includes groundbased piloted simulation and flight validation. This paper will give a status update of this program that will include a program overview, description of test methodology and preliminary results.

A Wide Band Absorbing Material Design Using Band-Pass Frequency Selective Surface

NASA Astrophysics Data System (ADS)

Xu, Yonggang; Xu, Qiang; Liu, Ting; Zheng, Dianliang; Zhou, Li

2018-03-01

Based on the high frequency advantage characteristics of the Fe based absorbing coating, a method for designing the structure of broadband absorbing structure by using frequency selective surface (FSS) is proposed. According to the transmission and reflection characteristic of the different size FSS structure, the frequency variation characteristic was simulated. Secondly, the genetic algorithm was used to optimize the high frequency broadband absorbing materials, including the single and double magnetic layer material. Finally, the absorbing characteristics in iron layer were analyzed as the band pass FSS structure was embedded, the results showed that the band-pass FSS had the influence on widening the absorbing frequency. As the FSS was set as the bottom layer, it was effective to achieve the good absorbing property in low frequency and the high frequency absorbing performance was not weakened, because the band-pass FSS led the low frequency absorption and the high frequency shielding effect. The results of this paper are of guiding significance for designing and manufacturing the broadband absorbing materials.

FORTRAN program for calculating total efficiency - specific speed characteristics of centrifugal compressors

NASA Technical Reports Server (NTRS)

Galvas, M. R.

1972-01-01

A computer program for predicting design point specific speed - efficiency characteristics of centrifugal compressors is presented with instructions for its use. The method permits rapid selection of compressor geometry that yields maximum total efficiency for a particular application. A numerical example is included to demonstrate the selection procedure.

Predicting Transition to Postsecondary Programs of GED® Earners in a College Setting

ERIC Educational Resources Information Center

Medina, Isabel

2014-01-01

This applied dissertation was designed to identify the characteristics of students enrolled in a GED® preparation program who transitioned to postsecondary programs at the same institution after passing the GED® test. The characteristics studied included age; gender; ethnicity; prematriculation scores in reading, language, and math in the Test of…

Measuring Family System Characteristics in Families Caring for Dementia Patients.

ERIC Educational Resources Information Center

Niederehe, George; And Others

This paper describes an ongoing study evaluating families that provide in-home care to elderly relatives wth dementia. Characteristics of the study, which include a focus on progressive senile dementia, use of a clinical approach, longitudinal design, descriptive nature, focus on the dyad of patient and primary caregiver, and use of videotaping…

Questions for Surveys

PubMed Central

Schaeffer, Nora Cate; Dykema, Jennifer

2011-01-01

We begin with a look back at the field to identify themes of recent research that we expect to continue to occupy researchers in the future. As part of this overview, we characterize the themes and topics examined in research about measurement and survey questions published in Public Opinion Quarterly in the past decade. We then characterize the field more broadly by highlighting topics that we expect to continue or to grow in importance, including the relationship between survey questions and the total survey error perspective, cognitive versus interactional approaches, interviewing practices, mode and technology, visual aspects of question design, and culture. Considering avenues for future research, we advocate for a decision-oriented framework for thinking about survey questions and their characteristics. The approach we propose distinguishes among various aspects of question characteristics, including question topic, question type and response dimension, conceptualization and operationalization of the target object, question structure, question form, response categories, question implementation, and question wording. Thinking about question characteristics more systematically would allow study designs to take into account relationships among these characteristics and identify gaps in current knowledge. PMID:24970951

Review of Combustion Stability Characteristics of Swirl Coaxial Element Injectors

NASA Technical Reports Server (NTRS)

Hulka, J. R.; Casiano, M. J.

2013-01-01

Liquid propellant rocket engine injectors using coaxial elements where the center liquid is swirled have become more common in the United States over the past several decades, although primarily for technology or advanced development programs. Currently, only one flight engine operates with this element type in the United States (the RL10 engine), while the element type is very common in Russian (and ex-Soviet) liquid propellant rocket engines. In the United States, the understanding of combustion stability characteristics of swirl coaxial element injectors is still very limited, despite the influx of experimental and theoretical information from Russia. The empirical and theoretical understanding is much less advanced than for the other prevalent liquid propellant rocket injector element types, the shear coaxial and like-on-like paired doublet. This paper compiles, compares and explores the combustion stability characteristics of swirl coaxial element injectors tested in the United States, dating back to J-2 and RL-10 development, and extending to very recent programs at the NASA MSFC using liquid oxygen and liquid methane and kerosene propellants. Included in this study are several other relatively recent design and test programs, including the Space Transportation Main Engine (STME), COBRA, J-2X, and the Common Extensible Cryogenic Engine (CECE). A presentation of the basic data characteristics is included, followed by an evaluation by several analysis techniques, including those included in Rocket Combustor Interactive Design and Analysis Computer Program (ROCCID), and methodologies described by Hewitt and Bazarov.

Characterization and development of truck load spectra and growth factors for current and future pavement design practices in Louisiana.

DOT National Transportation Integrated Search

2011-07-01

For pavement design practices, several factors must be considered to ensure good pavement performance over the anticipated life cycle. : Such factors include, but are not limited to, the type of paving materials, traffic loading characteristics, prev...

NanoElectronics and BioElectronics

NASA Technical Reports Server (NTRS)

Srivastava, Deepak

2001-01-01

This viewgraph presentation reviews the use of Carbon Nanotube electronics in the bioelectronics. Included is a brief review of the carbon nanotube manufacturing, the use of carbon nanotubes in Atomic Force Microscopy (AFM), and Computational Nanotechnology, that allows designers to understand nanotube characteristics and serves as a design tool.

Cognitive Styles and Distance Education.

ERIC Educational Resources Information Center

Liu, Yuliang; Ginther, Dean

1999-01-01

Considers how to adapt the design of distance education to students' cognitive styles. Discusses cognitive styles, including field dependence versus independence, holistic-analytic, sensory preference, hemispheric preferences, and Kolb's Learning Style Model; and the characteristics of distance education, including technology. (Contains 92…

STV engine design considerations

NASA Technical Reports Server (NTRS)

1991-01-01

The topics covered include the following: (1) engine design criteria and issues; (2) design requirements for man rating; (3) test requirements for man rating; (4) design requirements for space basing; (5) engine operation requirements; (6) health monitoring; (7) lunar transfer vehicle (LTV) feed system; (8) lunar excursion vehicle (LEV) propellant system; (9) area ratio gimbal angle limits; (10) reaction control system; and (11) engine configuration and characteristics. This document is presented in viewgraph form.

Large space telescope, phase A. Volume 3: Optical telescope assembly

NASA Technical Reports Server (NTRS)

1972-01-01

The development and characteristics of the optical telescope assembly for the Large Space Telescope are discussed. The systems considerations are based on mission-related parameters and optical equipment requirements. Information is included on: (1) structural design and analysis, (2) thermal design, (3) stabilization and control, (4) alignment, focus, and figure control, (5) electronic subsystem, and (6) scientific instrument design.

Diagnostic techniques for measurement of aerodynamic noise in free field and reverberant environment of wind tunnels

NASA Technical Reports Server (NTRS)

El-Sum, H. M. A.; Mawardi, O. K.

1973-01-01

Techniques for studying aerodynamic noise generating mechanisms without disturbing the flow in a free field, and in the reverberation environment of the ARC wind tunnel were investigated along with the design and testing of an acoustic antenna with an electronic steering control. The acoustic characteristics of turbojet as a noise source, detection of direct sound from a source in a reverberant background, optical diagnostic methods, and the design characteristics of a high directivity acoustic antenna. Recommendations for further studies are included.

Design and Construction for Community Health Service Precision Fund Appropriation System Based on Performance Management.

PubMed

Gao, Xing; He, Yao; Hu, Hongpu

2017-01-01

Allowing for the differences in economy development, informatization degree and characteristic of population served and so on among different community health service organizations, community health service precision fund appropriation system based on performance management is designed, which can provide support for the government to appropriate financial funds scientifically and rationally for primary care. The system has the characteristic of flexibility and practicability, in which there are five subsystems including data acquisition, parameter setting, fund appropriation, statistical analysis system and user management.

An Evaluation Research Model for System-Wide Textbook Selection.

ERIC Educational Resources Information Center

Talmage, Harriet; Walberg, Herbert T.

One component of an evaluation research model for system-wide selection of curriculum materials is reported: implementation of an evaluation design for obtaining data that permits professional and lay persons to base curriculum materials decisions on a "best fit" principle. The design includes teacher characteristics, learning environment…

A Literature Review of Academic Library Web Page Studies

ERIC Educational Resources Information Center

Blummer, Barbara

2007-01-01

In the early 1990s, numerous academic libraries adopted the web as a communication tool with users. The literature on academic library websites includes research on both design and navigation. Early studies typically focused on design characteristics, since websites initially merely provided information on the services and collections available in…

Revisiting Your Outdoor Environment: Reasons to Reshape, Enrich, Redevelop the Outdoor Space.

ERIC Educational Resources Information Center

Mauffette, Anne Gillain

1998-01-01

Provides suggestions for designing effective outdoor space. Focuses on advocating for space, designing spaces based on children's characteristics and preferences, integrating the outdoors in educational planning, including children in decision making and work, knowing about injury prevention, providing adult models who love the outdoors, and…

Group-sequential three-arm noninferiority clinical trial designs

PubMed Central

Ochiai, Toshimitsu; Hamasaki, Toshimitsu; Evans, Scott R.; Asakura, Koko; Ohno, Yuko

2016-01-01

We discuss group-sequential three-arm noninferiority clinical trial designs that include active and placebo controls for evaluating both assay sensitivity and noninferiority. We extend two existing approaches, the fixed margin and fraction approaches, into a group-sequential setting with two decision-making frameworks. We investigate the operating characteristics including power, Type I error rate, maximum and expected sample sizes, as design factors vary. In addition, we discuss sample size recalculation and its’ impact on the power and Type I error rate via a simulation study. PMID:26892481

48 CFR 1845.7101-1 - Property classification.

Code of Federal Regulations, 2010 CFR

2010-10-01

... aeronautical and space programs, which are capable of stand-alone operation. Examples include research aircraft... characteristics. (ii) Examples of NASA heritage assets include buildings and structures designated as National...., it no longer provides service to NASA operations). Examples of obsolete property are items in...

48 CFR 1845.7101-1 - Property classification.

Code of Federal Regulations, 2011 CFR

2011-10-01

... aeronautical and space programs, which are capable of stand-alone operation. Examples include research aircraft... characteristics. (ii) Examples of NASA heritage assets include buildings and structures designated as National...., it no longer provides service to NASA operations). Examples of obsolete property are items in...

48 CFR 1845.7101-1 - Property classification.

Code of Federal Regulations, 2014 CFR

2014-10-01

... aeronautical and space programs, which are capable of stand-alone operation. Examples include research aircraft... characteristics. (ii) Examples of NASA heritage assets include buildings and structures designated as National...., it no longer provides service to NASA operations). Examples of obsolete property are items in...

48 CFR 1845.7101-1 - Property classification.

Code of Federal Regulations, 2013 CFR

2013-10-01

... aeronautical and space programs, which are capable of stand-alone operation. Examples include research aircraft... characteristics. (ii) Examples of NASA heritage assets include buildings and structures designated as National...., it no longer provides service to NASA operations). Examples of obsolete property are items in...

48 CFR 1845.7101-1 - Property classification.

Code of Federal Regulations, 2012 CFR

2012-10-01

... aeronautical and space programs, which are capable of stand-alone operation. Examples include research aircraft... characteristics. (ii) Examples of NASA heritage assets include buildings and structures designated as National...., it no longer provides service to NASA operations). Examples of obsolete property are items in...

A review on the mechanical design elements of ankle rehabilitation robot.

PubMed

Khalid, Yusuf M; Gouwanda, Darwin; Parasuraman, Subramanian

2015-06-01

Ankle rehabilitation robots are developed to enhance ankle strength, flexibility and proprioception after injury and to promote motor learning and ankle plasticity in patients with drop foot. This article reviews the design elements that have been incorporated into the existing robots, for example, backdrivability, safety measures and type of actuation. It also discusses numerous challenges faced by engineers in designing this robot, including robot stability and its dynamic characteristics, universal evaluation criteria to assess end-user comfort, safety and training performance and the scientific basis on the optimal rehabilitation strategies to improve ankle condition. This article can serve as a reference to design robot with better stability and dynamic characteristics and good safety measures against internal and external events. It can also serve as a guideline for the engineers to report their designs and findings. © IMechE 2015.

Design, fabrication, testing and delivery of a solar collector

NASA Technical Reports Server (NTRS)

Sims, W. H.; Ballheim, R. W.; Bartley, S. M.; Smith, G. W.

1976-01-01

A two phase program encompassing the redesign and fabrication of a solar collector which is low in cost and aesthetically appealing is described. Phase one work reviewed the current collector design and developed a low-cost design based on specific design/performance/cost requirements. Throughout this phase selected collector component materials were evaluated by testing and by considering cost, installation, maintainability and durability. The resultant collector design was composed of an absorber plate, insulation, frame, cover, desiccant and sealant. In Phase two, three collector prototypes were fabricated and evaluated for both nonthermal and thermal characteristics. Tests included static load tests of covers, burst pressure tests of absorber plates, and tests for optical characteristics of selective absorber plate coatings. The three prototype collectors were shipped to Marshall Space Flight Center for use in their solar heating and cooling test facility.

Overview of Faculty Development Programs for Interprofessional Education.

PubMed

Ratka, Anna; Zorek, Joseph A; Meyer, Susan M

2017-06-01

Objectives. To describe characteristics of faculty development programs designed to facilitate interprofessional education, and to compile recommendations for development, delivery, and assessment of such faculty development programs. Methods. MEDLINE, CINAHL, ERIC, and Web of Science databases were searched using three keywords: faculty development, interprofessional education, and health professions. Articles meeting inclusion criteria were analyzed for emergent themes, including program design, delivery, participants, resources, and assessment. Results. Seventeen articles were identified for inclusion, yielding five characteristics of a successful program: institutional support; objectives and outcomes based on interprofessional competencies; focus on consensus-building and group facilitation skills; flexibility based on institution- and participant-specific characteristics; and incorporation of an assessment strategy. Conclusion. The themes and characteristics identified in this literature overview may support development of faculty development programs for interprofessional education. An advanced evidence base for interprofessional education faculty development programs is needed.

Human perceptual deficits as factors in computer interface test and evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowser, S.E.

1992-06-01

Issues related to testing and evaluating human computer interfaces are usually based on the machine rather than on the human portion of the computer interface. Perceptual characteristics of the expected user are rarely investigated, and interface designers ignore known population perceptual limitations. For these reasons, environmental impacts on the equipment will more likely be defined than will user perceptual characteristics. The investigation of user population characteristics is most often directed toward intellectual abilities and anthropometry. This problem is compounded by the fact that some deficits capabilities tend to be found in higher-than-overall population distribution in some user groups. The testmore » and evaluation community can address the issue from two primary aspects. First, assessing user characteristics should be extended to include tests of perceptual capability. Secondly, interface designs should use multimode information coding.« less

The HCMM system: Development and performance

NASA Technical Reports Server (NTRS)

Stuart, L. M., Jr.

1982-01-01

The structure and history of the heat capacity mapping mission program is reviewed and the spacecraft is described including engineering specifications, instrument design, data handling, and image characteristics.

Methodological characteristics and treatment effect sizes in oral health randomised controlled trials: Is there a relationship? Protocol for a meta-epidemiological study

PubMed Central

Saltaji, Humam; Armijo-Olivo, Susan; Cummings, Greta G; Amin, Maryam; Flores-Mir, Carlos

2014-01-01

Introduction It is fundamental that randomised controlled trials (RCTs) are properly conducted in order to reach well-supported conclusions. However, there is emerging evidence that RCTs are subject to biases which can overestimate or underestimate the true treatment effect, due to flaws in the study design characteristics of such trials. The extent to which this holds true in oral health RCTs, which have some unique design characteristics compared to RCTs in other health fields, is unclear. As such, we aim to examine the empirical evidence quantifying the extent of bias associated with methodological and non-methodological characteristics in oral health RCTs. Methods and analysis We plan to perform a meta-epidemiological study, where a sample size of 60 meta-analyses (MAs) including approximately 600 RCTs will be selected. The MAs will be randomly obtained from the Oral Health Database of Systematic Reviews using a random number table; and will be considered for inclusion if they include a minimum of five RCTs, and examine a therapeutic intervention related to one of the recognised dental specialties. RCTs identified in selected MAs will be subsequently included if their study design includes a comparison between an intervention group and a placebo group or another intervention group. Data will be extracted from selected trials included in MAs based on a number of methodological and non-methodological characteristics. Moreover, the risk of bias will be assessed using the Cochrane Risk of Bias tool. Effect size estimates and measures of variability for the main outcome will be extracted from each RCT included in selected MAs, and a two-level analysis will be conducted using a meta-meta-analytic approach with a random effects model to allow for intra-MA and inter-MA heterogeneity. Ethics and dissemination The intended audiences of the findings will include dental clinicians, oral health researchers, policymakers and graduate students. The aforementioned will be introduced to the findings through workshops, seminars, round table discussions and targeted individual meetings. Other opportunities for knowledge transfer will be pursued such as key dental conferences. Finally, the results will be published as a scientific report in a dental peer-reviewed journal. PMID:24568962

College Women Pursuing Careers in Science, Mathematics, and Engineering in the 1970s.

ERIC Educational Resources Information Center

McNamara, Patricia P.; Scherrei, Rita A.

The characteristics and persistence of young women who entered college during the 1970s and expressed an interest in science, math, and engineering (SME) are examined. The study design includes: (1) trend analysis of changes in characteristics of the science-oriented freshman pool from 1971-1979; (2) a longitudinal study of the educational and…

Patients' Characteristics and Providers' Attitudes: Predictors of Screening Pregnant Women for Illicit Substance Use

ERIC Educational Resources Information Center

Kerker, Bonnie D.; Horwitz, Sarah M.; Leventhal, John M.

2004-01-01

Objective: This study's aim was to determine how patients' and providers' characteristics affect hospital providers' decisions to screen pregnant and postpartum women for illicit substances. Methods: A retrospective design was used. Participants included all low-income women (N=1,100) who delivered at an urban teaching hospital over a 12-month…

Characteristics of Difficult-to-Place Youth in State Custody: A Profile of the Exceptional Care Pilot Project Population

ERIC Educational Resources Information Center

Armour, Marilyn P.; Schwab, James

2007-01-01

This study examines the characteristics of Texas youth designated as "most difficult to place" recipients of service under the "Exceptional Care Pilot Project" (N = 46). Findings include, among others, high levels of comorbid psychiatric disturbance (greater than 3 diagnostic groupings), physical (78.3%) and sexual (88%)…

Social Skills Scores: The Impact of Primary School Population Characteristics and Parental Involvement

ERIC Educational Resources Information Center

Dekker, Karien; Kamerling, Margje

2017-01-01

Purpose: The paper aims to examine to what extent and why parental involvement as well as characteristics of ethnic school population influence social skills scores (social position, behavioural skills) of students. Design/methodology/approach: The study used the COOL5-18 database (2010) that included 553 Dutch primary schools and nearly 38,000…

Two new planar coil designs for a high pressure radio frequency plasma source

NASA Astrophysics Data System (ADS)

Munsat, T.; Hooke, W. M.; Bozeman, S. P.; Washburn, S.

1995-04-01

Two planar coil designs for a high pressure rf plasma source are investigated using spectroscopic techniques and circuit analysis. In an Ar plasma a truncated version of the commonly used ``spiral'' coil is found to produce improvements in peak electron density of 20% over the full version. A coil with figure-8 geometry is found to move plasma inhomogeneities off of center and produce electron densities comparable to the spiral coils. Both of these characteristics are advantageous in industrial applications. Coil design characteristics for favorable power coupling are also determined, including the necessity of closed hydrodynamic plasma loops and the drawback of closely situated antiparallel coil currents.

Nanogel Carrier Design for Targeted Drug Delivery

PubMed Central

Eckmann, D. M.; Composto, R. J.; Tsourkas, A.; Muzykantov, V. R.

2014-01-01

Polymer-based nanogel formulations offer features attractive for drug delivery, including ease of synthesis, controllable swelling and viscoelasticity as well as drug loading and release characteristics, passive and active targeting, and the ability to formulate nanogel carriers that can respond to biological stimuli. These unique features and low toxicity make the nanogels a favorable option for vascular drug targeting. In this review, we address key chemical and biological aspects of nanogel drug carrier design. In particular, we highlight published studies of nanogel design, descriptions of nanogel functional characteristics and their behavior in biological models. These studies form a compendium of information that supports the scientific and clinical rationale for development of this carrier for targeted therapeutic interventions. PMID:25485112

Rotary balance data for a typical single-engine general aviation design for an angle-of-attack range of 8 deg to 90 deg. 1: Low-wing model A. [fluid flow and vortices data for general aviation aircraft to determine aerodynamic characteristics for various designs

NASA Technical Reports Server (NTRS)

Hultberg, R. S.; Mulcay, W.

1980-01-01

Aerodynamic characteristics obtained in a rotational flow environment utilizing a rotary balance are presented in plotted form for a 1/5 scale, single engine, low-wing, general aviation airplane model. The configuration tested included the basic airplane, various control deflections, tail designs, fuselage shapes, and wing leading edges. Data are presented without analysis for an angle of attack range of 8 to 90 deg and clockwise and counterclockwise rotations covering a range from 0 to 0.85.

Handling Qualities Implications for Crewed Spacecraft Operations

NASA Technical Reports Server (NTRS)

Bailey, Randall E.; Jackson, E. Bruce; Arthur, J. J.

2012-01-01

Abstract Handling qualities embody those qualities or characteristics of an aircraft that govern the ease and precision with which a pilot is able to perform the tasks required in support of an aircraft role. These same qualities are as critical, if not more so, in the operation of spacecraft. A research, development, test, and evaluation process was put into effect to identify, understand, and interpret the engineering and human factors principles which govern the pilot-vehicle dynamic system as they pertain to space exploration missions and tasks. Toward this objective, piloted simulations were conducted at the NASA Langley Research Center and Ames Research Center for earth-orbit proximity operations and docking and lunar landing. These works provide broad guidelines for the design of spacecraft to exhibit excellent handling characteristics. In particular, this work demonstrates how handling qualities include much more than just stability and control characteristics of a spacecraft or aircraft. Handling qualities are affected by all aspects of the pilot-vehicle dynamic system, including the motion, visual and aural cues of the vehicle response as the pilot performs the required operation or task. A holistic approach to spacecraft design, including the use of manual control, automatic control, and pilot intervention/supervision is described. The handling qualities implications of design decisions are demonstrated using these pilot-in-the-loop evaluations of docking operations and lunar landings.

Brayton Power Conversion System Parametric Design Modelling for Nuclear Electric Propulsion

NASA Technical Reports Server (NTRS)

Ashe, Thomas L.; Otting, William D.

1993-01-01

The parametrically based closed Brayton cycle (CBC) computer design model was developed for inclusion into the NASA LeRC overall Nuclear Electric Propulsion (NEP) end-to-end systems model. The code is intended to provide greater depth to the NEP system modeling which is required to more accurately predict the impact of specific technology on system performance. The CBC model is parametrically based to allow for conducting detailed optimization studies and to provide for easy integration into an overall optimizer driver routine. The power conversion model includes the modeling of the turbines, alternators, compressors, ducting, and heat exchangers (hot-side heat exchanger and recuperator). The code predicts performance to significant detail. The system characteristics determined include estimates of mass, efficiency, and the characteristic dimensions of the major power conversion system components. These characteristics are parametrically modeled as a function of input parameters such as the aerodynamic configuration (axial or radial), turbine inlet temperature, cycle temperature ratio, power level, lifetime, materials, and redundancy.

Designing capture trajectories to unstable periodic orbits around Europa

NASA Technical Reports Server (NTRS)

Russell, Ryan P.; Lam, Try

2006-01-01

The hostile environment of third body perturbations restricts a mission designer's ability to find well-behaved reproducible capture trajectories when dealing with limited control authority as is typical with low-thrust missions. The approach outlined in this paper confronts this shortcoming by utilizing dynamical systems theory and an extensive preexisting database of Restricted Three Body Problem (RTBP) periodic orbits. The stable manifolds of unstable periodic orbits are utilized to attract a spacecraft towards Europa. By selecting an appropriate periodic orbit, a mission designer can control important characteristics of the captured state including stability, minimum altitudes, characteristic inclinations, and characteristic radii among others. Several free parameters are optimized in the non-trivial mapping from the RTBP to a more realistic model. Although the ephemeris capture orbit is ballistic by design, low-thrust is used to target the state that leads to the capture orbit, control the spacecraft after arriving on the unstable quasi-periodic orbit, and begin the spiral down towards the science orbit. The approach allows a mission designer to directly target fuel efficient captures at Europa in an ephemeris model. Furthermore, it provides structure and controllability to the design of capture trajectories that reside in a chaotic environment.

Study of fuel cell powerplant with heat recovery

NASA Technical Reports Server (NTRS)

King, J. M.; Grasso, A. P.; Clausi, J. V.

1975-01-01

It was shown that heat can be recovered from fuel cell power plants by replacing the air-cooled heat exchangers in present designs with units which transfer the heat to the integrated utility system. Energy availability for a 40-kW power plant was studied and showed that the total usable energy at rated power represents 84 percent of the fuel lower heating value. The effects of design variables on heat availability proved to be small. Design requirements were established for the heat recovery heat exchangers, including measurement of the characteristics of two candidate fuel cell coolants after exposure to fuel cell operating conditions. A heat exchanger test program was defined to assess fouling and other characteristics of fuel cell heat exchangers needed to confirm heat exchanger designs for heat recovery.

Preliminary design data package, appendix C. [hybrid electric vehicles

NASA Technical Reports Server (NTRS)

1979-01-01

The data and documentation required to define the preliminary design of a near term hybrid vehicle and to quantify its operational characteristics are presented together with the assumptions and rationale behind the design decisions. Aspects discussed include development requirements for the propulsion system, the chassis system, the body, and the vehicle systems. Particular emphasis is given to the controls, the heat engine, and the batteries.

European Quality--Adding to the Debate?

ERIC Educational Resources Information Center

Birtwistle, Tim

1996-01-01

Two pilot programs designed to improve and maintain quality in European higher education are described and compared: an audit of universities' procedures for quality assurance; and an assessment of programs of study, including teaching and learning, student characteristics, staff, facilities, and quality management. Both include institutional…

Introduction to solar heating and cooling design and sizing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This manual is designed to introduce the practical aspects of solar heating/cooling systems to HVAC contractors, architects, engineers, and other interested individuals. It is intended to enable readers to assess potential solar heating/cooling applications in specific geographical areas, and includes tools necessary to do a preliminary design of the system and to analyze its economic benefits. The following are included: the case for solar energy; solar radiation and weather; passive solar design; system characteristics and selection; component performance criteria; determining solar system thermal performance and economic feasibility; requirements, availability, and applications of solar heating systems; and sources of additional information.more » (MHR)« less

EFFECT OF FLOW CHARACTERISTICS ON DO DISTRIBUTION IN A FULL SCALE OXIDATION DITCH WITH DIFFUSED AERATION AND VERTICAL FLOW BOOSTERS

NASA Astrophysics Data System (ADS)

Nakamachi, Kazuo; Fujiwara, Taku; Kawaguchi, Yukio; Tsuno, Hiroshi

The high loading rate oxidation ditch (OD) system with dual dissolved oxygen (DO) control has been developed for the purpose of advanced wastewater treatment and cost saving. For the purpose of scale-up to the real scale, the clean water experiments were conducted, with the full scale oxidation ditch with diffused aeration and vertical flow boosters, to examine the effect to the dual DO control by the design and operational factors, which include a flow characteristics and a oxygen supply capability. In this study, the flow characteristics of the OD channel were analyzed using a tank number and circulation ratio as the parameters. The analysis showed the complicated flow characteristics of the OD channel, which changed from the plug flow to the completely mixing transiently. Based on the tank number N =65~100 which were obtained from the tracer tests, a model of DO mass balance was constructed, then the accurate method for estimate the overall oxygen transfer coefficients was proposed. The potential error of the conventional method in the specific conditions was indicated. In addition, the effect of the flow characteristics on the design and operational parameters of the dual DO control, which include the circulation time or the DO profile, was clarified.

Characteristics of the Built Environment and the Presence of the Norway Rat in New York City: Results From a Neighborhood Rat Surveillance Program, 2008-2010.

PubMed

Johnson, Sarah; Bragdon, Caroline; Olson, Carolyn; Merlino, Mario; Bonaparte, Sancia

2016-06-01

Characteristics of an urban setting such as New York City (NYC), including readily available putrescible waste and ample underground infrastructure, make it highly attractive to the Norway rat (Rattus norvegicus). To identify property and neighborhood characteristics associated with rat presence, recent inspectional results were analyzed from over 77,000 properties in the Bronx and Manhattan. Variables capturing the location and density of factors believed to promote rat populations were tested individually and in combination in models predicting rat activity. We found that property-specific characteristics typically associated with high garbage volume, including large numbers of residential units, public ownership, and open-space designation (parks, outdoor recreation, or vacant land) were the most important factors in explaining increased rat presence across neighborhoods in NYC. Interventions that involved improved garbage management and street sanitation within a designated area reduced the likelihood of finding rats, especially in medium- and high-poverty neighborhoods. Neighborhood characteristics, such as being near a railroad or subway line, having a school nearby, the presence of numerous restaurants, or having older infrastructure, also contributed to the increased likelihood of rats. Our results support the use of built environment data to target community-level interventions and capture emerging rat infestations.

Study of Civil Markets for Heavy-Lift Airships

NASA Technical Reports Server (NTRS)

Mettam, P. J.; Hansen, D.; Chabot, C.; Byrne, R.

1978-01-01

The civil markets for heavy lift airships (HLAs) were defined by first identifying areas of most likely application. The operational suitability of HLAs for the applications identified were then assessed. The operating economics of HLAs were established and the market size for HLA services estimated by comparing HLA operating and economic characteristics with those of competing modes. The sensitivities of the market size to HLA characteristics were evaluated and the number and sizes of the vehicles required to service the more promising markets were defined. Important characteristics for future HLAs are discussed that were derived from the study of each application, including operational requirements, features enhancing profitability, military compatibility, improved design requirements, approach to entry into service, and institutional implications for design and operation.

Aerodynamic Design Using Neural Networks

NASA Technical Reports Server (NTRS)

Rai, Man Mohan; Madavan, Nateri K.

2003-01-01

The design of aerodynamic components of aircraft, such as wings or engines, involves a process of obtaining the most optimal component shape that can deliver the desired level of component performance, subject to various constraints, e.g., total weight or cost, that the component must satisfy. Aerodynamic design can thus be formulated as an optimization problem that involves the minimization of an objective function subject to constraints. A new aerodynamic design optimization procedure based on neural networks and response surface methodology (RSM) incorporates the advantages of both traditional RSM and neural networks. The procedure uses a strategy, denoted parameter-based partitioning of the design space, to construct a sequence of response surfaces based on both neural networks and polynomial fits to traverse the design space in search of the optimal solution. Some desirable characteristics of the new design optimization procedure include the ability to handle a variety of design objectives, easily impose constraints, and incorporate design guidelines and rules of thumb. It provides an infrastructure for variable fidelity analysis and reduces the cost of computation by using less-expensive, lower fidelity simulations in the early stages of the design evolution. The initial or starting design can be far from optimal. The procedure is easy and economical to use in large-dimensional design space and can be used to perform design tradeoff studies rapidly. Designs involving multiple disciplines can also be optimized. Some practical applications of the design procedure that have demonstrated some of its capabilities include the inverse design of an optimal turbine airfoil starting from a generic shape and the redesign of transonic turbines to improve their unsteady aerodynamic characteristics.

Nature's Miniature Architect

ERIC Educational Resources Information Center

Ross, Irwin

1977-01-01

Specific characteristics of the different spiders' webs are discussed. Photographs illustrate the various web designs and web-making spiders. Included also are the numerous uses a spider makes from its own web. (MA)

Results of design studies and wind tunnel tests of an advanced high lift system for an Energy Efficient Transport

NASA Technical Reports Server (NTRS)

Oliver, W. R.

1980-01-01

The development of an advanced technology high lift system for an energy efficient transport incorporating a high aspect ratio supercritical wing is described. This development is based on the results of trade studies to select the high lift system, analysis techniques utilized to design the high lift system, and results of a wind tunnel test program. The program included the first experimental low speed, high Reynolds number wind tunnel test for this class of aircraft. The experimental results include the effects on low speed aerodynamic characteristics of various leading and trailing edge devices, nacelles and pylons, aileron, spoilers, and Mach and Reynolds numbers. Results are discussed and compared with the experimental data and the various aerodynamic characteristics are estimated.

78 FR 9039 - Notice of Petition for Waiver of BSH Corporation From the Department of Energy Residential...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-07

... B authorizes the Secretary of Energy to prescribe test procedures that are reasonably designed to... was submitted contains one or more design characteristics that prevents testing of the basic model... materially inaccurate comparative data. 10 CFR 430.27(l). Petitioners must include in their petition any...

78 FR 65623 - Decision and Order Granting a Waiver to Samsung From the Department of Energy Residential...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-01

... B authorizes the Secretary of Energy to prescribe test procedures that are reasonably designed to... for which the petition for waiver was submitted contains one or more design characteristics that... to provide materially inaccurate comparative data. 10 CFR 430.27(a)(1). Petitioners must include in...

75 FR 13122 - Energy Conservation Program for Consumer Products: Decision and Order Granting a Waiver to the...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-18

... test procedures that are reasonably designed to produce results that measure energy efficiency, energy... petitioner's basic model contains one or more design characteristics that prevent testing according to the... materially inaccurate comparative data. 10 CFR 430.27(a)(1). Petitioners must include in their petition any...

Rotor systems research aircraft predesign study. Volume 4: Preliminary draft detail specification

NASA Technical Reports Server (NTRS)

Miller, A. N.; Linden, A. W.

1972-01-01

The RSRA requirements are presented in a detail specification format. Coverage of the requirements includes the following headings: (1) aircraft characteristics, (2) general features of design and construction, (3) aerodynamics, (4) structural design criteria, (5) flight control system, (6) propulsion subsystem, and (7) secondary power and distribution subsystem.

Teacher Responses to a Planning Framework for Junior Technology Classes Learning outside the Classroom

ERIC Educational Resources Information Center

Milne, Louise; Eames, Chris

2011-01-01

This paper describes teacher responses to a framework designed to support teacher planning for technology. It includes a learning experience outside the classroom [LEOTC] and is designed specifically for five-year-old students. The planning framework draws together characteristics of technology education, junior primary classrooms and LEOTC to…

Adaptivity in Educational Games: Including Player and Gameplay Characteristics

ERIC Educational Resources Information Center

Vandewaetere, Mieke; Cornillie, Frederik; Clarebout, Geraldine; Desmet, Piet

2013-01-01

The use of educational games for teaching and training is nowadays well-known, although its effectiveness in terms of learning and motivation has not been firmly corroborated. A first reason for this is that research on instructional design research often does not reach the fields of game development and game design. Consequently, instructional…

Computer Code Aids Design Of Wings

NASA Technical Reports Server (NTRS)

Carlson, Harry W.; Darden, Christine M.

1993-01-01

AERO2S computer code developed to aid design engineers in selection and evaluation of aerodynamically efficient wing/canard and wing/horizontal-tail configurations that includes simple hinged-flap systems. Code rapidly estimates longitudinal aerodynamic characteristics of conceptual airplane lifting-surface arrangements. Developed in FORTRAN V on CDC 6000 computer system, and ported to MS-DOS environment.

Open-Ended Learning Environments: A Theoretical Framework and Model for Design.

ERIC Educational Resources Information Center

Hill, Janette R.; Land, Susan M.

This paper presents a framework and model for design of open-ended learning environments (OELEs). First, an overview is presented that addresses key characteristics of OELEs, including: use of meaningful, complex contexts; provision of tools and resources; learner reflection and self-monitoring; and social, material, or technological scaffolding.…

Towards a characterization of information automation systems on the flight deck

NASA Astrophysics Data System (ADS)

Dudley, Rachel Feddersen

This thesis summarizes research to investigate the characteristics that define information automation systems used on aircraft flight decks and the significant impacts that these characteristics have on pilot performance. Major accomplishments of the work include the development of a set of characteristics that describe information automation systems on the flight deck and an experiment designed to study a subset of these characteristics. Information automation systems on the flight deck are responsible for the collection, processing, analysis, and presentation of data to the flightcrew. These systems pose human factors issues and challenges that must be considered by designers of these systems. Based on a previously developed formal definition of information automation for aircraft flight deck systems, an analysis process was developed and conducted to reach a refined set of information automation characteristics. In this work, characteristics are defined as a set of properties or attributes that describe an information automation system's operation or behavior, which can be used to identify and assess potential human factors issues. Hypotheses were formed for a subset of the characteristics: Automation Visibility, Information Quality, and Display Complexity. An experimental investigation was developed to measure performance impacts related to these characteristics, which showed mixed results of expected and surprising findings, with many interactions. A set of recommendations were then developed based on the experimental observations. Ensuring that the right information is presented to pilots at the right time and in the appropriate manner is the job of flight deck system designers. This work provides a foundation for developing recommendations and guidelines specific to information automation on the flight deck with the goal of improving the design and evaluation of information automation systems before they are implemented.

Recyclable automobiles. (Latest citations from Engineered Materials abstracts). Published Search

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

The bibliography contains citations concerning the technology and characteristics of non-metal, recyclable components used in automobiles. Existing polymer, plastic, and composite technology and materials are discussed. The citations also examine design and development of new recyclable materials that are durable. Design features and constraints are included. Some citations address future trends leading to the 100 percent recyclable automobile. (Contains a minimum of 77 citations and includes a subject term index and title list.)

Recyclable automobiles. (Latest citations from Engineered Materials abstracts). Published Search

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

The bibliography contains citations concerning the technology and characteristics of non-metal, recyclable components used in automobiles. Existing polymer, plastic, and composite technology and materials are discussed. The citations also examine design and development of new recyclable materials that are durable. Design features and constraints are included. Some citations address future trends leading to the 100 percent recyclable automobile. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

Recyclable automobiles. (Latest citations from Engineered Materials Abstracts). Published Search

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The bibliography contains citations concerning the technology and characteristics of non-metal, recyclable components used in automobiles. Existing polymer, plastic, and composite technology and materials are discussed. The citations also examine design and development of new recyclable materials that are durable. Design features and constraints are included. Some citations address future trends leading to the 100 percent recyclable automobile. (Contains a minimum of 58 citations and includes a subject term index and title list.)

Design optimisation of powers-of-two FIR filter using self-organising random immigrants GA

NASA Astrophysics Data System (ADS)

Chandra, Abhijit; Chattopadhyay, Sudipta

2015-01-01

In this communication, we propose a novel design strategy of multiplier-less low-pass finite impulse response (FIR) filter with the aid of a recent evolutionary optimisation technique, known as the self-organising random immigrants genetic algorithm. Individual impulse response coefficients of the proposed filter have been encoded as sum of signed powers-of-two. During the formulation of the cost function for the optimisation algorithm, both the frequency response characteristic and the hardware cost of the discrete coefficient FIR filter have been considered. The role of crossover probability of the optimisation technique has been evaluated on the overall performance of the proposed strategy. For this purpose, the convergence characteristic of the optimisation technique has been included in the simulation results. In our analysis, two design examples of different specifications have been taken into account. In order to substantiate the efficiency of our proposed structure, a number of state-of-the-art design strategies of multiplier-less FIR filter have also been included in this article for the purpose of comparison. Critical analysis of the result unambiguously establishes the usefulness of our proposed approach for the hardware efficient design of digital filter.

Designing and evaluating a STEM teacher learning opportunity in the research university.

PubMed

Hardré, Patricia L; Ling, Chen; Shehab, Randa L; Herron, Jason; Nanny, Mark A; Nollert, Matthias U; Refai, Hazem; Ramseyer, Christopher; Wollega, Ebisa D

2014-04-01

This study examines the design and evaluation strategies for a year-long teacher learning and development experience, including their effectiveness, efficiency and recommendations for strategic redesign. Design characteristics include programmatic features and outcomes: cognitive, affective and motivational processes; interpersonal and social development; and performance activities. Program participants were secondary math and science teachers, partnered with engineering faculty mentors, in a research university-based education and support program. Data from multiple sources demonstrated strengths and weaknesses in design of the program's learning environment, including: face-to-face and via digital tools; on-site and distance community interactions; and strategic evaluation tools and systems. Implications are considered for the strategic design and evaluation of similar grant-funded research experiences intended to support teacher learning, development and transfer. Copyright © 2013 Elsevier Ltd. All rights reserved.

Designing a Digital Instructional Management System To Optimize Early Education.

ERIC Educational Resources Information Center

Mooij, Ton

2002-01-01

Discusses digital instructional management systems (DIMSs) and describes a pilot study conducted in two Dutch kindergartens with a prototype DIMS that included individualization and optimization, that is matching curriculum with learner characteristics. Topics include learning processes for children at risk; and future plans. (LRW)

40 CFR 53.52 - Leak check test.

Code of Federal Regulations, 2014 CFR

2014-07-01

... MONITORING REFERENCE AND EQUIVALENT METHODS Procedures for Testing Physical (Design) and Performance Characteristics of Reference Methods and Class I and Class II Equivalent Methods for PM 2.5 or PM 10-2.5 § 53.52... to include the facility, including components, instruments, operator controls, a written procedure...

College Students' Goals, Plans, and Background Characteristics; A Synthesis of Three Empirical Studies.

ERIC Educational Resources Information Center

Fenske, Robert H.; Scott, Craig S.

This study was designed to provide longitudinal data bearing on the change and/or stability of college-bound students' educational and vocational goals, as well as their background characteristics. Data from three studies were contrasted and compared. Included in these studies were: (1) a 2-year followup of 4,009 junior college students; (2) a…

Exploring the Relationship between Career Interests and Work Values as Measured by the Choices Career Information Delivery System

ERIC Educational Resources Information Center

Dobson, Leila Kristine

2010-01-01

Person by environment fit is the most common approach used to support career decision making. In short, individuals learn how their personal characteristics can be "matched" to the occupations that correspond to those characteristics. Various career assessments have been designed to facilitate this matching process, including the O* "NET Interest…

Configuration design studies and wind tunnel tests of an energy efficient transport with a high-aspect-ratio supercritical wing

NASA Technical Reports Server (NTRS)

Henne, P. A.; Dahlin, J. A.; Peavey, C. C.; Gerren, D. S.

1982-01-01

The results of design studies and wind tunnel tests of high aspect ratio supercritical wings suitable for a medium range, narrow body transport aircraft flying near M=0.80 were presented. The basic characteristics of the wing design were derived from system studies of advanced transport aircraft where detailed structural and aerodynamic tradeoffs were used to determine the most optimum design from the standpoint of fuel usage and direct operating cost. These basic characteristics included wing area, aspect ratio, average thickness, and sweep. The detailed wing design was accomplished through application of previous test results and advanced computational transonic flow procedures. In addition to the basic wing/body development, considerable attention was directed to nacelle/plyon location effects, horizontal tail effects, and boundary layer transition effects. Results of these tests showed that the basic cruise performance objectives were met or exceeded.

A survey of Kaufman thruster cathodes

NASA Technical Reports Server (NTRS)

Weigand, A. J.; Nakanishi, S.

1971-01-01

A survey is presented of the various cathodes which were developed and used in the Kaufman ion thruster. The electron bombardment type ion source is briefly described. The general design, operating characteristics, and power requirements are shown for each type of cathode from the refractory metals used in 1960 to the plasma discharge hollow cathodes of today. A detailed discussion of the hollow cathode is given, including starting and cyclic operating characteristics as well as more fundamental design parameters. Tests to date show that the plasma hollow cathode is an efficient electron source with demonstrated durability over 10,000 hours.

Area estimation using multiyear designs and partial crop identification

NASA Technical Reports Server (NTRS)

Sielken, R. L., Jr.

1984-01-01

Statistical procedures were developed for large area assessments using both satellite and conventional data. Crop acreages, other ground cover indices, and measures of change were the principal characteristics of interest. These characteristics are capable of being estimated from samples collected possibly from several sources at varying times, with different levels of identification. Multiyear analysis techniques were extended to include partially identified samples; the best current year sampling design corresponding to a given sampling history was determined; weights reflecting the precision or confidence in each observation were identified and utilized, and the variation in estimates incorporating partially identified samples were quantified.

Overview of Faculty Development Programs for Interprofessional Education

PubMed Central

Zorek, Joseph A.; Meyer, Susan M.

2017-01-01

Objectives. To describe characteristics of faculty development programs designed to facilitate interprofessional education, and to compile recommendations for development, delivery, and assessment of such faculty development programs. Methods. MEDLINE, CINAHL, ERIC, and Web of Science databases were searched using three keywords: faculty development, interprofessional education, and health professions. Articles meeting inclusion criteria were analyzed for emergent themes, including program design, delivery, participants, resources, and assessment. Results. Seventeen articles were identified for inclusion, yielding five characteristics of a successful program: institutional support; objectives and outcomes based on interprofessional competencies; focus on consensus-building and group facilitation skills; flexibility based on institution- and participant-specific characteristics; and incorporation of an assessment strategy. Conclusion. The themes and characteristics identified in this literature overview may support development of faculty development programs for interprofessional education. An advanced evidence base for interprofessional education faculty development programs is needed. PMID:28720924

Refractive and relativistic effects on ITER low field side reflectometer design.

PubMed

Wang, G; Rhodes, T L; Peebles, W A; Harvey, R W; Budny, R V

2010-10-01

The ITER low field side reflectometer faces some unique design challenges, among which are included the effect of relativistic electron temperatures and refraction of probing waves. This paper utilizes GENRAY, a 3D ray tracing code, to investigate these effects. Using a simulated ITER operating scenario, characteristics of the reflected millimeter waves after return to the launch plane are quantified as a function of a range of design parameters, including antenna height, antenna diameter, and antenna radial position. Results for edge/SOL measurement with both O- and X-mode polarizations using proposed antennas are reported.

Theoretical and Measured Attenuation of Mufflers at Room Temperature Without Flow, with Comments on Engine-exhaust Muffler Design

NASA Technical Reports Server (NTRS)

Davis, Don D , Jr; Stevens, George L , Jr; Moore, Dewey; Stokes, George M

1953-01-01

Equations are presented for the attenuation characteristics of several types of mufflers. Experimental curves of attenuation plotted against frequency are presented for 77 different mufflers and the results are compared with theory. The experiments were made at room temperature without flow and the sound source was a loud-speaker. A method is given for including the tail pipe in the calculations. The application of the theory to the design of engine-exhaust mufflers is discussed, and charts have been included for the assistance of the designer.

Review of alternative fuels data bases

NASA Technical Reports Server (NTRS)

Harsha, P. T.; Edelman, R. B.

1983-01-01

Based on an analysis of the interaction of fuel physical and chemical properties with combustion characteristics and indicators, a ranking of the importance of various fuel properties with respect to the combustion process was established. This ranking was used to define a suite of specific experiments whose objective is the development of an alternative fuels design data base. Combustion characteristics and indicators examined include droplet and spray formation, droplet vaporization and burning, ignition and flame stabilization, flame temperature, laminar flame speed, combustion completion, soot emissions, NOx and SOx emissions, and the fuels' thermal and oxidative stability and fouling and corrosion characteristics. Key fuel property data is found to include composition, thermochemical data, chemical kinetic rate information, and certain physical properties.

Dynamic load-sharing characteristic analysis of face gear power-split gear system based on tooth contact characteristics

NASA Astrophysics Data System (ADS)

Dong, Hao; Hu, Yahui

2018-04-01

The bend-torsion coupling dynamics load-sharing model of the helicopter face gear split torque transmission system is established by using concentrated quality standard, to analyzing the dynamic load-sharing characteristic. The mathematical models include nonlinear support stiffness, time-varying meshing stiffness, damping, gear backlash. The results showed that the errors collectively influenced the load sharing characteristics, only reduce a certain error, it is never fully reached the perfect loading sharing characteristics. The system load-sharing performance can be improved through floating shaft support. The above-method will provide a theoretical basis and data support for its dynamic performance optimization design.

Space shuttle seal material and design development for earth storable propellant systems

NASA Technical Reports Server (NTRS)

1973-01-01

The results of a program to investigate and characterize seal materials suitable for space shuttle storable propellant systems are given. Two new elastomeric materials were identified as being potentially superior to existing state-of-the art materials for specific sealing applications. These materials were AF-E-124D and AF-E-411. AF-E-124D is a cured perfluorinated polymer suitable for use with dinitrogen tetroxide oxidizer, and hydrazine base fuels. AF-E-411 is an ethylene propylene terpolymer material for hydrazine base fuel service. Data are presented relative to low and high temperature characteristics as well as propellant exposure effects. Types of data included are: mechanical properties, stress strain curves, friction and wear characteristics, compression set and permeability. Sealing tests with a flat poppet-seal valve were conducted for verification of sealing capability. A bibliography includes over 200 references relating to seal design or materials and presents a concise tabulation of the more useful seal design data sources.

Investigation of cryogenic rupture disc design

NASA Technical Reports Server (NTRS)

Keough, J. B.; Oldland, A. H.

1973-01-01

Rupture disc designs of both the active (command actuated) and passive (pressure ruptured) types were evaluated for performance characteristics at cryogenic temperatures and for capability to operate in a variety of cryogens, including gaseous and liquid fluorine. The test results, coupled with information from literature and industry searches, were used to establish a statement of design criteria and recommended practices for application of rupture discs to cryogenic rocket propellant feed and vent systems.

Quiet aircraft design and operational characteristics

NASA Technical Reports Server (NTRS)

Hodge, Charles G.

1991-01-01

The application of aircraft noise technology to the design and operation of aircraft is discussed. Areas of discussion include the setting of target airplane noise levels, operational considerations and their effect on noise, and the sequencing and timing of the design and development process. Primary emphasis is placed on commercial transport aircraft of the type operated by major airlines. Additionally, noise control engineering of other types of aircraft is briefly discussed.

Biomarker-Guided Adaptive Trial Designs in Phase II and Phase III: A Methodological Review

PubMed Central

Antoniou, Miranta; Jorgensen, Andrea L; Kolamunnage-Dona, Ruwanthi

2016-01-01

Background Personalized medicine is a growing area of research which aims to tailor the treatment given to a patient according to one or more personal characteristics. These characteristics can be demographic such as age or gender, or biological such as a genetic or other biomarker. Prior to utilizing a patient’s biomarker information in clinical practice, robust testing in terms of analytical validity, clinical validity and clinical utility is necessary. A number of clinical trial designs have been proposed for testing a biomarker’s clinical utility, including Phase II and Phase III clinical trials which aim to test the effectiveness of a biomarker-guided approach to treatment; these designs can be broadly classified into adaptive and non-adaptive. While adaptive designs allow planned modifications based on accumulating information during a trial, non-adaptive designs are typically simpler but less flexible. Methods and Findings We have undertaken a comprehensive review of biomarker-guided adaptive trial designs proposed in the past decade. We have identified eight distinct biomarker-guided adaptive designs and nine variations from 107 studies. Substantial variability has been observed in terms of how trial designs are described and particularly in the terminology used by different authors. We have graphically displayed the current biomarker-guided adaptive trial designs and summarised the characteristics of each design. Conclusions Our in-depth overview provides future researchers with clarity in definition, methodology and terminology for biomarker-guided adaptive trial designs. PMID:26910238

An Overview of Structural Characteristics in Problematic Video Game Playing.

PubMed

Griffiths, Mark D; Nuyens, Filip

2017-01-01

There are many different factors involved in how and why people develop problems with video game playing. One such set of factors concerns the structural characteristics of video games (i.e., the structure, elements, and components of the video games themselves). Much of the research examining the structural characteristics of video games was initially based on research and theorizing from the gambling studies field. The present review briefly overviews the key papers in the field to date. The paper examines a number of areas including (i) similarities in structural characteristics of gambling and video gaming, (ii) structural characteristics in video games, (iii) narrative and flow in video games, (iv) structural characteristic taxonomies for video games, and (v) video game structural characteristics and game design ethics. Many of the studies carried out to date are small-scale, and comprise self-selected convenience samples (typically using self-report surveys or non-ecologically valid laboratory experiments). Based on the small amount of empirical data, it appears that structural features that take a long time to achieve in-game are the ones most associated with problematic video game play (e.g., earning experience points, managing in-game resources, mastering the video game, getting 100% in-game). The study of video games from a structural characteristic perspective is of benefit to many different stakeholders including academic researchers, video game players, and video game designers, as well as those interested in prevention and policymaking by making the games more socially responsible. It is important that researchers understand and recognize the psycho-social effects and impacts that the structural characteristics of video games can have on players, both positive and negative.

Lithium batteries. (Latest citations from the COMPENDEX database). Published Search

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1993-05-01

The bibliography contains citations concerning the design, development, and applications of lithium batteries. Topics include electrochemical aspects, cycling characteristics, performance evaluations, and applications in cardiac pacemaker devices. Batteries using organic compounds, chlorides, and metal sulfides are discussed. (Contains 250 citations and includes a subject term index and title list.)

40 CFR 53.52 - Leak check test.

Code of Federal Regulations, 2011 CFR

2011-07-01

... MONITORING REFERENCE AND EQUIVALENT METHODS Procedures for Testing Physical (Design) and Performance Characteristics of Reference Methods and Class I and Class II Equivalent Methods for PM2.5 or PM10â2.5 § 53.52... to include the facility, including components, instruments, operator controls, a written procedure...

40 CFR 53.52 - Leak check test.

Code of Federal Regulations, 2012 CFR

2012-07-01

... MONITORING REFERENCE AND EQUIVALENT METHODS Procedures for Testing Physical (Design) and Performance Characteristics of Reference Methods and Class I and Class II Equivalent Methods for PM2.5 or PM10â2.5 § 53.52... to include the facility, including components, instruments, operator controls, a written procedure...

40 CFR 53.52 - Leak check test.

Code of Federal Regulations, 2010 CFR

2010-07-01

... MONITORING REFERENCE AND EQUIVALENT METHODS Procedures for Testing Physical (Design) and Performance Characteristics of Reference Methods and Class I and Class II Equivalent Methods for PM2.5 or PM10â2.5 § 53.52... to include the facility, including components, instruments, operator controls, a written procedure...

Quiet engine program flight engine design study

NASA Technical Reports Server (NTRS)

Klapproth, J. F.; Neitzel, R. E.; Seeley, C. T.

1974-01-01

The results are presented of a preliminary flight engine design study based on the Quiet Engine Program high-bypass, low-noise turbofan engines. Engine configurations, weight, noise characteristics, and performance over a range of flight conditions typical of a subsonic transport aircraft were considered. High and low tip speed engines in various acoustically treated nacelle configurations were included.

Transparent superstrate terrestrial solar cell module

NASA Technical Reports Server (NTRS)

1977-01-01

The design, development, fabrication, and testing of the transparent solar cell module were examined. Cell performance and material process characteristics were determined by extensive tests and design modifications were made prior to preproduction fabrication. These tests included three cell submodules and two full size engineering modules. Along with hardware and test activity, engineering documentation was prepared and submitted.

78 FR 53448 - Energy Conservation Program for Consumer Products: Decision and Order Granting a Waiver to BSH...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-29

... Secretary of Energy to prescribe test procedures that are reasonably designed to produce results which... conditions is met: (1) The petitioner's basic model contains one or more design characteristics that prevent... to provide materially inaccurate comparative data. (10 CFR 430.27(a)(1)) Petitioners must include in...

76 FR 48149 - Notice of Petition for Waiver of Samsung Electronics America, Inc. From the Department of Energy...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-08

... authorizes the Secretary of Energy to prescribe test procedures that are reasonably designed to produce... waiver was submitted contains one or more design characteristics that prevents testing of the basic model... materially inaccurate comparative data. 10 CFR 430.27(l). Petitioners must include in their petition any...

Advanced Telemetry System Development.

DTIC Science & Technology

Progress in advanced telemetry system development is described. Discussions are included of studies leading to the specification for design...characteristics of adaptive and analytical telemetry systems in which the information efficiently utilizes the data channel capacity. Also discussed are...Progress indicates that further sophistication of existing designs in telemetry will be less advantageous than the development of new systems of

Mutant maize variety containing the glt1-1 allele

DOEpatents

Nelson, Oliver E.; Pan, David

1994-01-01

A maize plant has in its genome a non-mutable form of a mutant allele designated vitX-8132. The allele is located at a locus designated as glt which conditions kernels having an altered starch characteristic. Maize plants including such a mutant allele produce a starch that does not increase in viscosity on cooling, after heating.

77 FR 5782 - Notice of Petition for Waiver of Hill PHOENIX From the Department of Energy Commercial...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-06

... that are reasonably designed to produce results which measure energy efficiency, energy use, or... waiver was submitted contains one or more design characteristics that prevents testing of the basic model... materially inaccurate comparative data. 10 CFR 431.401(f)(4). Petitioners must include in their petition any...

Compilation of Test Data on 111 Free-Spinning Airplane Models Tested in the Langley 15-Foot and 20-Foot Free-Spinning Tunnels

NASA Technical Reports Server (NTRS)

Malvestuto, Frank S.; Gale, Lawrence J.; Wood, John H.

1947-01-01

A compilation of free-spinning-airplane model data on the spin and recovery characteristics of 111 airplanes is presented. These data were previously published in separate memorandum reports and were obtained from free-spinning tests in the Langley 15-foot and the Langley 20-foot free-spinning tunnels. The model test data presented include the steady-spin and recovery characteristics of each model for various combinations of aileron and elevator deflections and for various loadings and dimensional configurations. Dimensional data, mass data, and a three-view drawing of the corresponding free-spinning tunnel model are also presented for each airplane. The data presented should be of value to designers and should facilitate the design of airplanes incorporating satisfactory spin-recovery characteristics.

Lost in translation: bridging gaps between design and evidence-based design.

PubMed

Watkins, Nicholas; Keller, Amy

2008-01-01

The healthcare design community is adopting evidence-based design (EBD) at a startling rate. However, the role of research within an architectural practice is unclear. Reasons for the lack of clarity include multiple connotations of EBD, the tension between a research-driven market and market-driven research, and the competing expectations and standards of design practitioners and researchers. Research as part of EBD should be integral with the design process so that research directly contributes to building projects. Characteristics of a comprehensive programming methodology to close the gap between design and EBD are suggested.

Program Aids Design Of Fluid-Circulating Systems

NASA Technical Reports Server (NTRS)

Bacskay, Allen; Dalee, Robert

1992-01-01

Computer Aided Systems Engineering and Analysis (CASE/A) program is interactive software tool for trade study and analysis, designed to increase productivity during all phases of systems engineering. Graphics-based command-driven software package provides user-friendly computing environment in which engineer analyzes performance and interface characteristics of ECLS/ATC system. Useful during all phases of spacecraft-design program, from initial conceptual design trade studies to actual flight, including pre-flight prediction and in-flight analysis of anomalies. Written in FORTRAN 77.

Consumers' perception of organic product characteristics. A review.

PubMed

Schleenbecker, Rosa; Hamm, Ulrich

2013-12-01

Consumer interest in organic products is growing alongside a diversification of the supply. In order to serve consumers actual needs and wants regarding organic products, those involved in the market need to be informed about consumers' perception of organic products. Therefore, the state of research as regards consumers' perception of organic product characteristics, including basic and additional characteristics, product labelling, product innovations and the range of products on the market is displayed in this contribution. A comprehensive literature analysis was performed uncovering not only the state of the art in the field including employed methodology, but also research needs. Most studies are published on consumers' perception of organic products' design and labelling. A trend towards the so called 'organic-plus' positioning can be perceived, with many consumers expecting an extensive orientation towards sustainability. The diversity of product labels features prominently in related studies. The demand for reliable information, as well as the low degree of awareness of many labels amongst consumers becomes clear in these studies. To date, few results are available on consumers' perception of packaging and design of organic products, and even fewer for consumers' perception of range design. Both consumers' perception of organic product innovation and valued added services are untouched so far. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ceramics for Solar Receivers

NASA Technical Reports Server (NTRS)

Kudirka, A. A.

1984-01-01

Materials for high-temperature use reviewed. Report discusses characteristics of ceramics and assesses potential of candidate materials in solar receivers. Design requirements presented, including those for receiver with fluid exit temperatures up to 1,425 degrees C.

An unmanned probe to Pluto

NASA Technical Reports Server (NTRS)

1990-01-01

Now that Voyager II has completed its grand tour of the solar system, all the planets in the solar system, with the exception of Pluto, have been studied. Even now, missions to return to Mercury, Venus, Mars Jupiter, and Saturn are currently flying or are planned. However, a mission to explore Pluto is not, at the present time, being considered seriously. The design problem presented to the students was very general, i.e., design an unmanned mission to Pluto with a launch window constraint of the years 2000 to 2010. All other characteristics of the mission, such as mission type (flyby, orbiter, lander, penetrator), scientific objectives and payload, and the propulsion system were to be determined by the design teams. The design studies exposed several general problems to be solved. Due to the extreme distance to Pluto (and a corresponding travel time in the range of 10 to 25 years), the spacecraft had to be lighter and more robust than current spacecraft designs. In addition, advanced propulsion concepts had to be considered. These included the new generation of launch vehicles and upper stages and nuclear electric propulsion. The probe design offered an abundance of synthesis and analysis problems. These included sizing trade studies, selection of subsystem components, analysis of spacecraft dynamics, stability and control, structural design and material selection, trajectory design, and selection of scientific equipment. Since the characteristics of the mission, excluding the launch window, were to be determined by the design teams, the solutions varied widely.

Energy efficient engine: Flight propulsion system preliminary analysis and design

NASA Technical Reports Server (NTRS)

Johnston, R. P.; Beitler, R. S.; Bobinger, R. O.; Broman, C. L.; Gravitt, R. D.; Heineke, H.; Holloway, P. R.; Klem, J. S.; Nash, D. O.; Ortiz, P.

1980-01-01

The characteristics of an advanced flight propulsion system (FPS), suitable for introduction in the late 1980's to early 1990's, was more fully defined. It was determined that all goals for efficiency, environmental considerations, and economics could be met or exceeded with the possible exception of NOx emission. In evaluating the FPS, all aspects were considered including component design, performance, weight, initial cost, maintenance cost, engine system integration (including nacelle), and aircraft integration considerations. The current FPS installed specific fuel consumption was reduced 14.2% from that of the CF6-50C reference engine. When integrated into an advanced, subsonic, study transport, the FPS produced a fuel burn savings of 15 to 23% and a direct operating cost reduction of 5 to 12% depending on the mission and study aircraft characteristics relative to the reference engine.

Innovation in Aerodynamic Design Features of Soviet Missiles

NASA Technical Reports Server (NTRS)

Spearman, M. Leroy

2006-01-01

Wind tunnel investigations of some tactical and strategic missile systems developed by the former Soviet Union have been included in the basic missile research programs of the NACA/NASA. Studies of the Soviet missiles sometimes revealed innovative design features that resulted in unusual or unexpected aerodynamic characteristics. In some cases these characteristics have been such that the measured performance of the missile exceeds what might have been predicted. In other cases some unusual design features have been found that would alleviate what might otherwise have been a serious aerodynamic problem. In some designs, what has appeared to be a lack of refinement has proven to be a matter of expediency. It is a purpose of this paper to describe some examples of unusual design features of some Soviet missiles and to illustrate the effectiveness of the design features on the aerodynamic behavior of the missile. The paper draws on the experience of the author who for over 60 years was involved in the aerodynamic wind tunnel testing of aircraft and missiles with the NACA/NASA.

The Effect of Pupils' Race, Class, Test Scores, and Classroom Behavior on the Academic Expectancies of Southern and Non-Southern White Teachers.

ERIC Educational Resources Information Center

Long, Barbara H.; Henderson, Edmund H.

This investigation of the causal dynamics of teacher expectancies is carried out in an artificial setting, making use of contrived stimulus children. Characteristics of stimulus persons were varied in a 2 by 2 factorial design. Pupil characteristics included race (black or white) and class (lower or middle). Different groups of subjects rated each…

InSb charge coupled infrared imaging device: The 20 element linear imager

NASA Technical Reports Server (NTRS)

Thom, R. D.; Koch, T. L.; Parrish, W. J.; Langan, J. D.; Chase, S. C.

1980-01-01

The design and fabrication of the 8585 InSb charge coupled infrared imaging device (CCIRID) chip are reported. The InSb material characteristics are described along with mask and process modifications. Test results for the 2- and 20-element CCIRID's are discussed, including gate oxide characteristics, charge transfer efficiency, optical mode of operation, and development of the surface potential diagram.

An analysis of characteristics of post-authorisation studies registered on the ENCePP EU PAS Register

PubMed Central

Carroll, Robert; Ramagopalan, Sreeram V.; Cid-Ruzafa, Javier; Lambrelli, Dimitra; McDonald, Laura

2017-01-01

Background: The objective of this study was to investigate the study design characteristics of Post-Authorisation Studies (PAS) requested by the European Medicines Agency which were recorded on the European Union (EU) PAS Register held by the European Network of Centres for Pharmacoepidemiology and Pharmacovigilance (ENCePP). Methods: We undertook a cross-sectional descriptive analysis of all studies registered on the EU PAS Register as of 18 th October 2016. Results: We identified a total of 314 studies on the EU PAS Register, including 81 (26%) finalised, 160 (51%) ongoing and 73 (23%) planned. Of those studies identified, 205 (65%) included risk assessment in their scope, 133 (42%) included drug utilisation and 94 (30%) included effectiveness evaluation. Just over half of the studies (175; 56%) used primary data capture, 135 (43%) used secondary data and 4 (1%) used a hybrid design combining both approaches. Risk assessment and effectiveness studies were more likely to use primary data capture (60% and 85% respectively as compared to 39% and 14% respectively for secondary). The converse was true for drug utilisation studies where 59% were secondary vs. 39% for primary. For type 2 diabetes mellitus, database studies were more commonly used (80% vs 3% chart review, 3% hybrid and 13% primary data capture study designs) whereas for studies in oncology, primary data capture were more likely to be used (85% vs 4% chart review, and 11% database study designs). Conclusions: Results of this analysis show that PAS design varies according to study objectives and therapeutic area. PMID:29188016

Earth radiation budget measurement from a spinning satellite: Conceptual design of detectors

NASA Technical Reports Server (NTRS)

Sromovsky, L. A.; Revercomb, H. E.; Suomi, V. E.

1975-01-01

The conceptual design, sensor characteristics, sensor performance and accuracy, and spacecraft and orbital requirements for a spinning wide-field-of-view earth energy budget detector were investigated. The scientific requirements for measurement of the earth's radiative energy budget are presented. Other topics discussed include the observing system concept, solar constant radiometer design, plane flux wide FOV sensor design, fast active cavity theory, fast active cavity design and error analysis, thermopile detectors as an alternative, pre-flight and in-flight calibration plane, system error summary, and interface requirements.

Multidisciplinary design optimization of aircraft wing structures with aeroelastic and aeroservoelastic constraints

NASA Astrophysics Data System (ADS)

Jung, Sang-Young

Design procedures for aircraft wing structures with control surfaces are presented using multidisciplinary design optimization. Several disciplines such as stress analysis, structural vibration, aerodynamics, and controls are considered simultaneously and combined for design optimization. Vibration data and aerodynamic data including those in the transonic regime are calculated by existing codes. Flutter analyses are performed using those data. A flutter suppression method is studied using control laws in the closed-loop flutter equation. For the design optimization, optimization techniques such as approximation, design variable linking, temporary constraint deletion, and optimality criteria are used. Sensitivity derivatives of stresses and displacements for static loads, natural frequency, flutter characteristics, and control characteristics with respect to design variables are calculated for an approximate optimization. The objective function is the structural weight. The design variables are the section properties of the structural elements and the control gain factors. Existing multidisciplinary optimization codes (ASTROS* and MSC/NASTRAN) are used to perform single and multiple constraint optimizations of fully built up finite element wing structures. Three benchmark wing models are developed and/or modified for this purpose. The models are tested extensively.

Demonstration of decomposition and optimization in the design of experimental space systems

NASA Technical Reports Server (NTRS)

Padula, Sharon; Sandridge, Chris A.; Haftka, Raphael T.; Walsh, Joanne L.

1989-01-01

Effective design strategies for a class of systems which may be termed Experimental Space Systems (ESS) are needed. These systems, which include large space antenna and observatories, space platforms, earth satellites and deep space explorers, have special characteristics which make them particularly difficult to design. It is argued here that these same characteristics encourage the use of advanced computer-aided optimization and planning techniques. The broad goal of this research is to develop optimization strategies for the design of ESS. These strategics would account for the possibly conflicting requirements of mission life, safety, scientific payoffs, initial system cost, launch limitations and maintenance costs. The strategies must also preserve the coupling between disciplines or between subsystems. Here, the specific purpose is to describe a computer-aided planning and scheduling technique. This technique provides the designer with a way to map the flow of data between multidisciplinary analyses. The technique is important because it enables the designer to decompose the system design problem into a number of smaller subproblems. The planning and scheduling technique is demonstrated by its application to a specific preliminary design problem.

Double-injection, deep-impurity switch development

NASA Technical Reports Server (NTRS)

Selim, F. A.; Whitson, D. W.

1983-01-01

The overall objective of this program is the development of device design and process techniques for the fabrication of a double-injection, deep-impurity (DI)(2) silicon switch that operates in the 1-10 kV range with conduction current of 10 and 1A, respectively. Other major specifications include a holding voltage of 0 to 5 volts at 1 A anode current, 10 microsecond switching time, and power dissipation of 50 W at 75 C. This report describes work that shows how the results obtained at the University of Cincinnati under NASA Grant NSG-3022 have been applied to larger area and higher voltage devices. The investigations include theoretical, analytical, and experimental studies of device design and processing. Methods to introduce deep levels, such as Au diffusion and electron irradiation, have been carried out to "pin down' the Fermi level and control device-switching characteristics. Different anode, cathode, and gate configurations are presented. Techniques to control the surface electric field of planar structures used for (DI)(2) switches are examined. Various sections of this report describe the device design, wafer-processing techniques, and various measurements which include ac and dc characteristics, 4-point probe, and spreading resistance.

Implementation of a Smart Phone for Motion Analysis.

PubMed

Yodpijit, Nantakrit; Songwongamarit, Chalida; Tavichaiyuth, Nicha

2015-01-01

In today’s information-rich environment, one of the most popular devices is a smartphone. Research has shown significant growth in the use of smartphones and apps all over the world. Accelerometer within smartphone is a motion sensor that can be used to detect human movements. Compared to other major vital signs, gait characteristics represent general health status, and can be determined using smartphones. The objective of the current study is to design and develop the alternative technology that can potentially predict health status and reduce healthcare cost. This study uses a smartphone as a wireless accelerometer for quantifying human motion characteristics from four steps of the system design and development (data acquisition operation, feature extraction algorithm, classifier design, and decision making strategy). Findings indicate that it is possible to extract features from a smartphone’s accelerometer using a peak detection algorithm. Gait characteristics obtain from the peak detection algorithm include stride time, stance time, swing time and cadence. Applications and limitations of this study are also discussed.

The development of an augmentor wing jet STOL research aircraft (modified C-8A). Volume 2: Analysis of contractor's flight test

NASA Technical Reports Server (NTRS)

Skavdahl, H.; Patterson, D. H.

1972-01-01

The initial flight test phase of the modified C-8A airplane was conducted. The primary objective of the testing was to establish the basic airworthiness of the research vehicle. This included verification of the structural design and evaluation of the aircraft's systems. Only a minimum amount of performance testing was scheduled; this has been used to provide a preliminary indication of the airplane's performance and flight characteristics for future flight planning. The testing included flutter and loads investigations up to the maximum design speed. The operational characteristics of all systems were assessed including hydraulics, environmental control system, air ducts, the vectoring conical nozzles, and the stability augmentation system (SAS). Approaches to stall were made at three primary flap settings: up, 30 deg and 65 deg, but full stalls were not scheduled. Minimum control speeds and maneuver margins were checked. All takeoffs and landings were conventional, and STOL performance was not scheduled during this phase of the evaluation.

Improving estimates of streamflow characteristics using LANDSAT-1 (ERTS-1) imagery. [Delmarva Peninsula

NASA Technical Reports Server (NTRS)

Hollyday, E. F. (Principal Investigator)

1975-01-01

The author has identified the following significant results. Streamflow characteristics in the Delmarva Peninsula derived from the records of daily discharge of 20 gaged basins are representative of the full range in flow conditions and include all of those commonly used for design or planning purposes. They include annual flood peaks with recurrence intervals of 2, 5, 10, 25, and 50 years, mean annual discharge, standard deviation of the mean annual discharge, mean monthly discharges, standard deviation of the mean monthly discharges, low-flow characteristics, flood volume characteristics, and the discharge equalled or exceeded 50 percent of the time. Streamflow and basin characteristics were related by a technique of multiple regression using a digital computer. A control group of equations was computed using basin characteristics derived from maps and climatological records. An experimental group of equations was computed using basin characteristics derived from LANDSAT imagery as well as from maps and climatological records. Based on a reduction in standard error of estimate equal to or greater than 10 percent, the equations for 12 stream flow characteristics were substantially improved by adding to the analyses basin characteristics derived from LANDSAT imagery.

Control group design, contamination and drop-out in exercise oncology trials: a systematic review.

PubMed

Steins Bisschop, Charlotte N; Courneya, Kerry S; Velthuis, Miranda J; Monninkhof, Evelyn M; Jones, Lee W; Friedenreich, Christine; van der Wall, Elsken; Peeters, Petra H M; May, Anne M

2015-01-01

Important considerations for exercise trials in cancer patients are contamination and differential drop-out among the control group members that might jeopardize the internal validity. This systematic review provides an overview of different control groups design characteristics of exercise-oncology trials and explores the association with contamination and drop-out rates. Randomized controlled exercise-oncology trials from two Cochrane reviews were included. Additionally, a computer-aided search using Medline (Pubmed), Embase and CINAHL was conducted after completion date of the Cochrane reviews. Eligible studies were classified according to three control group design characteristics: the exercise instruction given to controls before start of the study (exercise allowed or not); and the intervention the control group was offered during (any (e.g., education sessions or telephone contacts) or none) or after (any (e.g., cross-over or exercise instruction) or none) the intervention period. Contamination (yes or no) and excess drop-out rates (i.e., drop-out rate of the control group minus the drop-out rate exercise group) were described according to the three design characteristics of the control group and according to the combinations of these three characteristics; so we additionally made subgroups based on combinations of type and timing of instructions received. 40 exercise-oncology trials were included based on pre-specified eligibility criteria. The lowest contamination (7.1% of studies) and low drop-out rates (excess drop-out rate -4.7±9.2) were found in control groups offered an intervention after the intervention period. When control groups were offered an intervention both during and after the intervention period, contamination (0%) and excess drop-out rates (-10.0±12.8%) were even lower. Control groups receiving an intervention during and after the study intervention period have lower contamination and drop-out rates. The present findings can be considered when designing future exercise-oncology trials.

Distributed digital signal processors for multi-body structures

NASA Technical Reports Server (NTRS)

Lee, Gordon K.

1990-01-01

Several digital filter designs were investigated which may be used to process sensor data from large space structures and to design digital hardware to implement the distributed signal processing architecture. Several experimental tests articles are available at NASA Langley Research Center to evaluate these designs. A summary of some of the digital filter designs is presented, an evaluation of their characteristics relative to control design is discussed, and candidate hardware microcontroller/microcomputer components are given. Future activities include software evaluation of the digital filter designs and actual hardware inplementation of some of the signal processor algorithms on an experimental testbed at NASA Langley.

First year progress report on the development of the Texas flexible pavement database.

DOT National Transportation Integrated Search

2008-01-01

Comprehensive and reliable databases are essential for the development, validation, and calibration of any pavement : design and rehabilitation system. These databases should include material properties, pavement structural : characteristics, highway...

Elephants: Big, Strong and Wise. Young Discovery Library Series.

ERIC Educational Resources Information Center

Pfeffer, Pierre

This book is written for children ages 5 through 10. Part of a series designed to develop their curiosity, fascinate them and educate them, this volume examines the characteristics and natural history of elephants. Topics included are: (1) elephant's ancestors; (2) elephant life; and (3) training elephants for work. Quiz items are included. (YP)

45 CFR 287.130 - Can NEW Program activities include job market assessments, job creation and economic development...

Code of Federal Regulations, 2012 CFR

2012-10-01

... Program Design and Operations § 287.130 Can NEW Program activities include job market assessments, job...) Communication with any training, research, or educational agencies that have produced economic development plans...-sufficiency of program participants; (6) Surveys to collect information regarding client characteristics; and...

45 CFR 287.130 - Can NEW Program activities include job market assessments, job creation and economic development...

Code of Federal Regulations, 2013 CFR

2013-10-01

... Program Design and Operations § 287.130 Can NEW Program activities include job market assessments, job...) Communication with any training, research, or educational agencies that have produced economic development plans...-sufficiency of program participants; (6) Surveys to collect information regarding client characteristics; and...

45 CFR 287.130 - Can NEW Program activities include job market assessments, job creation and economic development...

Code of Federal Regulations, 2010 CFR

2010-10-01

... Program Design and Operations § 287.130 Can NEW Program activities include job market assessments, job...) Communication with any training, research, or educational agencies that have produced economic development plans...-sufficiency of program participants; (6) Surveys to collect information regarding client characteristics; and...

Lithium batteries. (Latest citations from the EI Compendex*plus database). Published Search

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1994-12-01

The bibliography contains citations concerning the design, development, and applications of lithium batteries. Topics include electrochemical aspects, cycling characteristics, performance evaluations, and applications in cardiac pacemaker devices. Batteries using organic compounds, chlorides, and metal sulfides are discussed. (Contains 250 citations and includes a subject term index and title list.)

Lithium batteries. (Latest citations from the EI Compendex*plus database). Published Search

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1994-03-01

The bibliography contains citations concerning the design, development, and applications of lithium batteries. Topics include electrochemical aspects, cycling characteristics, performance evaluations, and applications in cardiac pacemaker devices. Batteries using organic compounds, chlorides, and metal sulfides are discussed. (Contains 250 citations and includes a subject term index and title list.)

Design and material selection for inverter transformer cores

NASA Technical Reports Server (NTRS)

Mclyman, W. T.

1973-01-01

Report is announced which studied magnetic properties of candidate materials for use in spacecraft transformers, static inverters, converters, and transformer-rectifier power supplies. Included are material characteristics for available alloy compositions in tabular form, including: trade names, saturated flux density, dc coercive force, loop squareness, material density, and watts per pound at 3 KHz.

A suite of phantom-based test methods for assessing image quality of photoacoustic tomography systems

NASA Astrophysics Data System (ADS)

Vogt, William C.; Jia, Congxian; Wear, Keith A.; Garra, Brian S.; Pfefer, T. Joshua

2017-03-01

As Photoacoustic Tomography (PAT) matures and undergoes clinical translation, objective performance test methods are needed to facilitate device development, regulatory clearance and clinical quality assurance. For mature medical imaging modalities such as CT, MRI, and ultrasound, tissue-mimicking phantoms are frequently incorporated into consensus standards for performance testing. A well-validated set of phantom-based test methods is needed for evaluating performance characteristics of PAT systems. To this end, we have constructed phantoms using a custom tissue-mimicking material based on PVC plastisol with tunable, biologically-relevant optical and acoustic properties. Each phantom is designed to enable quantitative assessment of one or more image quality characteristics including 3D spatial resolution, spatial measurement accuracy, ultrasound/PAT co-registration, uniformity, penetration depth, geometric distortion, sensitivity, and linearity. Phantoms contained targets including high-intensity point source targets and dye-filled tubes. This suite of phantoms was used to measure the dependence of performance of a custom PAT system (equipped with four interchangeable linear array transducers of varying design) on design parameters (e.g., center frequency, bandwidth, element geometry). Phantoms also allowed comparison of image artifacts, including surface-generated clutter and bandlimited sensing artifacts. Results showed that transducer design parameters create strong variations in performance including a trade-off between resolution and penetration depth, which could be quantified with our method. This study demonstrates the utility of phantom-based image quality testing in device performance assessment, which may guide development of consensus standards for PAT systems.

Advanced supersonic technology concept study: Hydrogen fueled configuration

NASA Technical Reports Server (NTRS)

Brewer, G. D.

1974-01-01

Conceptual designs of hydrogen fueled supersonic transport configurations for the 1990 time period were developed and compared with equivalent technology Jet A-1 fueled vehicles to determine the economic and performance potential of liquid hydrogen as an alternate fuel. Parametric evaluations of supersonic cruise vehicles with varying design and transport mission characteristics established the basis for selecting a preferred configuration which was then studied in greater detail. An assessment was made of the general viability of the selected concept including an evaluation of costs and environmental considerations, i.e., exhaust emissions and sonic boom characteristics. Technology development requirements and suggested implementation schedules are presented.

A compact roller-gear pitch-yaw joint module: Design and control issues

NASA Technical Reports Server (NTRS)

Dohring, Mark E.; Anderson, William J.; Newman, Wyatt S.; Rohn, Douglas A.

1993-01-01

Robotic systems have been proposed as a means of accomplishing assembly and maintenance tasks in space. The desirable characteristics of these systems include compact size, low mass, high load capacity, and programmable compliance to improve assembly performance. In addition, the mechanical system must transmit power in such a way as to allow high performance control of the system. Efficiency, linearity, low backlash, low torque ripple, and low friction are all desirable characteristics. This work presents a pitch-yaw joint module designed and built to address these issues. Its effectiveness as a two degree-of-freedom manipulator using natural admittance control, a method of force control, is demonstrated.

Design of power-plant installations pressure-loss characteristics of duct components

NASA Technical Reports Server (NTRS)

Henry, John R

1944-01-01

A correlation of what are believed to be the most reliable data available on duct components of aircraft power-plant installations is presented. The information is given in a convenient form and is offered as an aid in designing duct systems and, subject to certain qualifications, as a guide in estimating their performance. The design and performance data include those for straight ducts; simple bends of square, circular, and elliptical cross sections; compound bends; diverging and converging bends; vaned bends; diffusers; branch ducts; internal inlets; and an angular placement of heat exchangers. Examples are included to illustrate methods of applying these data in analyzing duct systems. (author)

Mutant maize variety containing the glt1-1 allele

DOEpatents

Nelson, O.E.; Pan, D.

1994-07-19

A maize plant has in its genome a non-mutable form of a mutant allele designated vitX-8132. The allele is located at a locus designated as glt which conditions kernels having an altered starch characteristic. Maize plants including such a mutant allele produce a starch that does not increase in viscosity on cooling, after heating. 2 figs.

Insulated Masonry Cavity Walls. Proceedings of the Research Correlation Conference by the Building Research Institute, Division of Engineering and Industrial Research. (April 1960).

ERIC Educational Resources Information Center

National Academy of Sciences - National Research Council, Washington, DC.

Publication of conference paper texts include --(1) history and development of masonry cavity walls, (2) recent research related to determination of thermal and moisture resistance, (3) wall design and detailing, (4) design for crack prevention, (5) mortar specification characteristics, (6) performance experience with low-rise buildings, (7)…

Mechanical design and performance specifications of anthropomorphic prosthetic hands: a review.

PubMed

Belter, Joseph T; Segil, Jacob L; Dollar, Aaron M; Weir, Richard F

2013-01-01

In this article, we set forth a detailed analysis of the mechanical characteristics of anthropomorphic prosthetic hands. We report on an empirical study concerning the performance of several commercially available myoelectric prosthetic hands, including the Vincent, iLimb, iLimb Pulse, Bebionic, Bebionic v2, and Michelangelo hands. We investigated the finger design and kinematics, mechanical joint coupling, and actuation methods of these commercial prosthetic hands. The empirical findings are supplemented with a compilation of published data on both commercial and prototype research prosthetic hands. We discuss numerous mechanical design parameters by referencing examples in the literature. Crucial design trade-offs are highlighted, including number of actuators and hand complexity, hand weight, and grasp force. Finally, we offer a set of rules of thumb regarding the mechanical design of anthropomorphic prosthetic hands.

The characteristics and interpretability of land surface change and implications for project design

USGS Publications Warehouse

Sohl, Terry L.; Gallant, Alisa L.; Loveland, Thomas R.

2004-01-01

The need for comprehensive, accurate information on land-cover change has never been greater. While remotely sensed imagery affords the opportunity to provide information on land-cover change over large geographic expanses at a relatively low cost, the characteristics of land-surface change bring into question the suitability of many commonly used methodologies. Algorithm-based methodologies to detect change generally cannot provide the same level of accuracy as the analyses done by human interpreters. Results from the Land Cover Trends project, a cooperative venture that includes the U.S. Geological Survey, Environmental Protection Agency, and National Aeronautics and Space Administration, have shown that land-cover conversion is a relatively rare event, occurs locally in small patches, varies geographically and temporally, and is spectrally ambiguous. Based on these characteristics of change and the type of information required, manual interpretation was selected as the primary means of detecting change in the Land Cover Trends project. Mixtures of algorithm-based detection and manual interpretation may often prove to be the most feasible and appropriate design for change-detection applications. Serious examination of the expected characteristics and measurability of change must be considered during the design and implementation phase of any change analysis project.

Design forms of total knee replacement.

PubMed

Walker, P S; Sathasivam, S

2000-01-01

The starting point of this article is a general design criterion applicable to all types of total knee replacement. This criterion is then expanded upon to provide more specifics of the required kinematics, and the forces which the total knee must sustain. A characteristic which differentiates total knees is the amount of constraint which is required, and whether the constraint is translational or rotational. The different forms of total knee replacement are described in terms of these constraints, starting with the least constrained unicompartments to the almost fully constrained fixed and rotating hinges. Much attention is given to the range of designs in between these two extreme types, because they constitute by far the largest in usage. This category includes condylar replacements where the cruciate ligaments are preserved or resected, posterior cruciate substituting designs and mobile bearing knees. A new term, 'guided motion knees', is applied to the growing number of designs which control the kinematics by the use of intercondylar cams or specially shaped and even additional bearing surfaces. The final section deals with the selection of an appropriate design of total knee for specific indications based on the design characteristics.

Model Test of the Aerospace Laser Propulsion Engine

NASA Astrophysics Data System (ADS)

Ageichik, Alexander A.; Egorov, Maxim S.; Ostapenko, Svetlana V.; Rezunkov, Yuri A.; Safronov, Alexander L.; Stepanov, Vladimir V.

2005-04-01

One of the main results of the experimental and theoretical investigations made under the ISTC Project ♯ 1801 is the original design of Aerospace Laser Propulsion Engine (ASLPE) developed. The designed characteristics of the ASLPE flight model are experimentally approved, including the test experiments with a solid propellant. The obtained momentum coupling coefficient is rather high and comparable one with respect to the coefficient obtained by other researchers. Moreover, it is experimentally demonstrated that the thrust characteristics of the ASLPE flight model does not depend on angular aberrations of the beam coming onto the beam concentrator of the model with the incident angle of 0.01 radian. The experiments also demonstrated that successful launching of the vehicle with the ASLPE under the laser characteristics is possible also if the vehicle mass will be decreased and the thermal blooming effect will be eliminated.

Space shuttle booster separation motor design

NASA Technical Reports Server (NTRS)

Smith, G. W.; Chase, C. A.

1976-01-01

The separation characteristics of the space shuttle solid rocket boosters (SRBs) are introduced along with the system level requirements for the booster separation motors (BSMs). These system requirements are then translated into specific motor requirements that control the design of the BSM. Each motor component is discussed including its geometry, material selection, and fabrication process. Also discussed is the propellant selection, grain design, and performance capabilities of the motor. The upcoming test program to develop and qualify the motor is outlined.

Solar Concentrator Advanced Development Program

NASA Technical Reports Server (NTRS)

Knasel, Don; Ehresman, Derik

1989-01-01

The Solar Concentrator Advanced Development Project has successfully designed, fabricated, and tested a full scale prototypical solar dynamic concentrator for space station applications. A Truss Hexagonal Panel reflector was selected as a viable solar concentrator concept to be used for space station applications. This concentrator utilizes a modular design approach and is flexible in attainable flux profiles and assembly techniques. The detailed design of the concentrator, which included structural, thermal and optical analysis, identified the feasibility of the design and specific technologies that were required to fabricate it. The needed surface accuracy of the reflectors surface was found to be very tight, within 5 mrad RMS slope error, and results in very close tolerances for fabrication. To meet the design requirements, a modular structure composed of hexagonal panels was used. The panels, made up of graphite epoxy box beams provided the strength, stiffness and dimensional stability needed. All initial project requirements were met or exceeded by hardware demonstration. Initial testing of structural repeatability of a seven panel portion of the concentrator was followed by assembly and testing of the full nineteen panel structure. The testing, which consisted of theodolite and optical measurements over an assembly-disassembly-reassembly cycle, demonstrated that the concentrator maintained the as-built contour and optical characteristics. The facet development effort within the project, which included developing the vapor deposited reflective facet, produced a viable design with demonstrated optical characteristics that are within the project goals.

The study of vehicle classification equipment with solutions to improve accuracy in Oklahoma.

DOT National Transportation Integrated Search

2014-12-01

The accuracy of vehicle counting and classification data is vital for appropriate future highway and road : design, including determining pavement characteristics, eliminating traffic jams, and improving safety. : Organizations relying on vehicle cla...

Improving Factor Score Estimation Through the Use of Observed Background Characteristics

PubMed Central

Curran, Patrick J.; Cole, Veronica; Bauer, Daniel J.; Hussong, Andrea M.; Gottfredson, Nisha

2016-01-01

A challenge facing nearly all studies in the psychological sciences is how to best combine multiple items into a valid and reliable score to be used in subsequent modelling. The most ubiquitous method is to compute a mean of items, but more contemporary approaches use various forms of latent score estimation. Regardless of approach, outside of large-scale testing applications, scoring models rarely include background characteristics to improve score quality. The current paper used a Monte Carlo simulation design to study score quality for different psychometric models that did and did not include covariates across levels of sample size, number of items, and degree of measurement invariance. The inclusion of covariates improved score quality for nearly all design factors, and in no case did the covariates degrade score quality relative to not considering the influences at all. Results suggest that the inclusion of observed covariates can improve factor score estimation. PMID:28757790

Water quality and habitat conditions in upper Midwest streams relative to riparian vegetation and soil characteristics, August 1997 : study design, methods, and data

USGS Publications Warehouse

Sorenson, S.K.; Porter, S.D.; Akers, K.B.; Harris, M.A.; Kalkhoff, S.J.; Lee, K.E.; Roberts, L.; Terrio, P.J.

1999-01-01

Water-chemistry, biological, and habitat data were collected from 70 sites on Midwestern streams during August 1997 as part of an integrated, regional water-quality assessment by the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program. The study area includes the Corn Belt region of southern Minnesota, eastern Iowa, and west-central Illinois, one of the most intensive and productive agricultural regions of the world. The focus of the study was to evaluate the condition of woodedriparian zones and the influence of basin soildrainage characteristics on water quality and biological-community responses. This report includes a description of the study design and site-characterization process, sample-collection and processing methods, laboratory methods, quality-assurance procedures, and summaries of data on nutrients, herbicides and metabolites, stream productivity and respiration, biological communities, habitat conditions, and agriculturalchemical and land-use information.

Tank Investigation of a Powered Dynamic Model of a Large Long-Range Flying Boat

NASA Technical Reports Server (NTRS)

Parkinson, John B; Olson, Roland E; Harr, Marvin I

1947-01-01

Principles for designing the optimum hull for a large long-range flying boat to meet the requirements of seaworthiness, minimum drag, and ability to take off and land at all operational gross loads were incorporated in a 1/12-size powered dynamic model of a four-engine transport flying boat having a design gross load of 165,000 pounds. These design principles included the selection of a moderate beam loading, ample forebody length, sufficient depth of step, and close adherence to the form of a streamline body. The aerodynamic and hydrodynamic characteristics of the model were investigated in Langley tank no. 1. Tests were made to determine the minimum allowable depth of step for adequate landing stability, the suitability of the fore-and-aft location of the step, the take-off performance, the spray characteristics, and the effects of simple spray-control devices. The application of the design criterions used and test results should be useful in the preliminary design of similar large flying boats.

Development and Evaluation of a Performance Modeling Flight Test Approach Based on Quasi Steady-State Maneuvers

NASA Technical Reports Server (NTRS)

Yechout, T. R.; Braman, K. B.

1984-01-01

The development, implementation and flight test evaluation of a performance modeling technique which required a limited amount of quasisteady state flight test data to predict the overall one g performance characteristics of an aircraft. The concept definition phase of the program include development of: (1) the relationship for defining aerodynamic characteristics from quasi steady state maneuvers; (2) a simplified in flight thrust and airflow prediction technique; (3) a flight test maneuvering sequence which efficiently provided definition of baseline aerodynamic and engine characteristics including power effects on lift and drag; and (4) the algorithms necessary for cruise and flight trajectory predictions. Implementation of the concept include design of the overall flight test data flow, definition of instrumentation system and ground test requirements, development and verification of all applicable software and consolidation of the overall requirements in a flight test plan.

Simulations of Atmospheric Plasma Arcs

NASA Astrophysics Data System (ADS)

Pearcy, Jacob; Chopra, Nirbhav; Jaworski, Michael

2017-10-01

We present the results of computer simulation of cylindrical plasma arcs with characteristics similar to those predicted to be relevant in magnetohydrodynamic (MHD) power conversion systems. These arcs, with core temperatures on the order of 1 eV, place stringent limitations on the lifetime of conventional electrodes used in such systems, suggesting that a detailed analysis of arc characteristics will be crucial in designing more robust electrode systems. Simulations utilize results from NASA's Chemical Equilibrium with Applications (CEA) program to solve the Elenbaas-Heller equation in a variety of plasma compositions, including approximations of coal-burning plasmas as well as pure gas discharges. The effect of carbon dioxide injection on arc characteristics, emulating discharges from molten carbonate salt electrodes, is also analyzed. Results include radial temperature profiles, composition maps, and current-voltage (IV) characteristics of these arcs. Work supported by DOE contract DE-AC02-09CH11466.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Palomar, J.; Wyman, R.

This document provides recommendations to guide reviewers in the application of Programmable Logic Controllers (PLCS) to the control, monitoring and protection of nuclear reactors. The first topics addressed are system-level design issues, specifically including safety. The document then discusses concerns about the PLC manufacturing organization and the protection system engineering organization. Supplementing this document are two appendices. Appendix A summarizes PLC characteristics. Specifically addressed are those characteristics that make the PLC more suitable for emergency shutdown systems than other electrical/electronic-based systems, as well as characteristics that improve reliability of a system. Also covered are PLC characteristics that may create anmore » unsafe operating environment. Appendix B provides an overview of the use of programmable logic controllers in emergency shutdown systems. The intent is to familiarize the reader with the design, development, test, and maintenance phases of applying a PLC to an ESD system. Each phase is described in detail and information pertinent to the application of a PLC is pointed out.« less

Trust in automation: designing for appropriate reliance.

PubMed

Lee, John D; See, Katrina A

2004-01-01

Automation is often problematic because people fail to rely upon it appropriately. Because people respond to technology socially, trust influences reliance on automation. In particular, trust guides reliance when complexity and unanticipated situations make a complete understanding of the automation impractical. This review considers trust from the organizational, sociological, interpersonal, psychological, and neurological perspectives. It considers how the context, automation characteristics, and cognitive processes affect the appropriateness of trust. The context in which the automation is used influences automation performance and provides a goal-oriented perspective to assess automation characteristics along a dimension of attributional abstraction. These characteristics can influence trust through analytic, analogical, and affective processes. The challenges of extrapolating the concept of trust in people to trust in automation are discussed. A conceptual model integrates research regarding trust in automation and describes the dynamics of trust, the role of context, and the influence of display characteristics. Actual or potential applications of this research include improved designs of systems that require people to manage imperfect automation.

Topics in LIFE Target Survival: 11-SI-004 Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miles, Robin; Benett, Bill; Bond, Tiziana

The LIFE target design incorporates many considerations to generate the desired fusion gain including the physics design, the cost of manufacturing of the target, the injectability of the target, the aerodynamic flight characteristics of the target, the ability to track and engage the target and to maintain the structural and thermal integrity of the target. This document describes the effort that was made in support of issues of survivability of the target during injection which included issues massmanufactural materials and processes which could be used in the target.

Sealed nickel cadmium batteries

NASA Astrophysics Data System (ADS)

Raudszus, W.; Kiehne, H. A.; Cloke, F. R.

1982-10-01

The design, manufacture, and application of maintenance-free sealed NiCd batteries are surveyed. The principles of electrochemical power supplies and the history of the development of NiCd cells are reviewed. The batteries produced by Varta Batterie AG are presented; topics discussed include design parameters, electrical and physical characteristics, performance under adverse conditions, type range, production, and quality control. Application techniques, including cell-type choice, charging units and charging circuits, and the construction of standby power supplies, are considered, with reference to national and international standards of performance and classification. No individual items are abstracted in this volume

Flat conductor cable design, manufacture, and installation

NASA Technical Reports Server (NTRS)

Angele, W.; Hankins, J. D.

1973-01-01

Pertinent information for hardware selection, design, manufacture, and quality control necessary for flat conductor cable interconnecting harness application is presented. Comparisons are made between round wire cable and flat conductor cable. The flat conductor cable interconnecting harness systems show major cost, weight, and space savings, plus increased system performance and reliability. The design application section includes electrical characteristics, harness design and development, and a full treatise on EMC considerations. Manufacturing and quality control sections pertain primarily to the developed conductor-contact connector system and special flat conductor cable to round wire cable transitions.

Optimal Design of Spring Characteristics of Damper for Subharmonic Vibration in Automatic Transmission Powertrain

NASA Astrophysics Data System (ADS)

Nakae, T.; Ryu, T.; Matsuzaki, K.; Rosbi, S.; Sueoka, A.; Takikawa, Y.; Ooi, Y.

2016-09-01

In the torque converter, the damper of the lock-up clutch is used to effectively absorb the torsional vibration. The damper is designed using a piecewise-linear spring with three stiffness stages. However, a nonlinear vibration, referred to as a subharmonic vibration of order 1/2, occurred around the switching point in the piecewise-linear restoring torque characteristics because of the nonlinearity. In the present study, we analyze vibration reduction for subharmonic vibration. The model used herein includes the torque converter, the gear train, and the differential gear. The damper is modeled by a nonlinear rotational spring of the piecewise-linear spring. We focus on the optimum design of the spring characteristics of the damper in order to suppress the subharmonic vibration. A piecewise-linear spring with five stiffness stages is proposed, and the effect of the distance between switching points on the subharmonic vibration is investigated. The results of our analysis indicate that the subharmonic vibration can be suppressed by designing a damper with five stiffness stages to have a small spring constant ratio between the neighboring springs. The distances between switching points must be designed to be large enough that the amplitude of the main frequency component of the systems does not reach the neighboring switching point.

Icing-Protection Requirements for Reciprocating-Engine Induction System

NASA Technical Reports Server (NTRS)

Coles, Willard D; Rollin, Vern G; Mulholland, Donald R

1950-01-01

Despite the development of relatively ice-free fuel-metering systems, the widespread use of alternate and heated-air intakes, and the use of alcohol for emergency de-icing, icing of aircraft-engine induction systems is a serious problem. Investigations have been made to study and to combat all phases of this icing problem. From these investigations, criterions for safe operation and for design of new induction systems have been established. The results were obtained from laboratory investigations of carburetor-supercharger combinations, wind-tunnel investigations of air scoops, multicylinder-engine studies, and flight investigations. Characteristics of three forms of ice, impact, throttling, and fuel evaporation were studied. The effects of several factors on the icing characteristics were also studied and included: (1) atmospheric conditions, (2) engine and air-scoop configurations, including light-airplane system, (3) type fuel used, and (4) operating variables, such as power condition, use of a manifold pressure regulator, mixture setting, carburetor heat, and water-alcohol injection. In addition, ice-detection methods were investigated and methods of preventing and removing induction-system ice were studied. Recommendations are given for design and operation with regard to induction-system design.

Design charts for predicting downwash angles and wake characteristics behind plain and flapped wings

NASA Technical Reports Server (NTRS)

Silverstein, Abe; Katzoff, S

1939-01-01

Equations and design charts are given for predicting the downwash angles and the wake characteristics for power-off conditions behind plain and flapped wings of the types used in modern design practice. The downwash charts cover the cases of elliptical wings and wings of taper ratios 1, 2, 3, and 5, with aspect ratios of 6, 9, and 12, having flaps covering 0, 40, 70, and 100 percent of the span. Curves of the span load distributions for all these cases are included. Data on the lift and the drag of flapped airfoil sections and curves for finding the contribution of the flap to the total wing lift for different types of flap and for the entire range of flap spans are also included. The wake width and the distribution of dynamic pressure across the wake are given in terms of the profile-drag coefficient and the distance behind the wing. A method of estimating the wake position is also given. The equations and charts are based on theory that has been shown in a previous report to be in agreement with experiment.

The impact of solar cell technology on planar solar array performance

NASA Technical Reports Server (NTRS)

Mills, Michael W.; Kurland, Richard M.

1989-01-01

The results of a study into the potential impact of advanced solar cell technologies on the characteristics (weight, cost, area) of typical planar solar arrays designed for low, medium and geosynchronous altitude earth orbits are discussed. The study considered planar solar array substrate designs of lightweight, rigid-panel graphite epoxy and ultra-lightweight Kapton. The study proposed to answer the following questions: Do improved cell characteristics translate into array-level weight, size and cost improvements; What is the relative importance of cell efficiency, weight and cost with respect to array-level performance; How does mission orbital environment affect array-level performance. Comparisons were made at the array level including all mechanisms, hinges, booms, and harnesses. Array designs were sized to provide 5kW of array power (not spacecraft bus power, which is system dependent but can be scaled from given values). The study used important grass roots issues such as use of the GaAs radiation damage coefficients as determined by Anspaugh. Detailed costing was prepared, including cell and cover costs, and manufacturing attrition rates for the various cell types.

Application of Solar-Electric Propulsion to Robotic and Human Missions in Near-Earth Space

NASA Technical Reports Server (NTRS)

Woodcock, Gordon

2006-01-01

Solar-electric propulsion (SEP) is becoming of interest for application to a wide range of missions. The benefits of SEP are strongly influenced by system element performance, especially that for the power system. Solar array performance is increasing rapidly and promises to continue to do so for another 10 to 20 years (Fig. 1). At the same time, cost per watt is decreasing. Radiation hardness is increasing. New concepts for how to design a SEP are emerging. These improvements lead to changes in the best ways to apply SEP technology to missions, and broadening of the practical uses of SEP technology compared to competing technologies. This paper addresses the evolving characteristics of SEP technology from the point of view of mission design, and how mission profile characteristics can be designed to best take advantage of evolving SEP characteristics. Mission concepts include robotic lunar landers and orbiters; scientific planetary spacecraft; delivery of spacecraft to geosynchronous orbit from inclined and low-inclination launch orbits; and lunar cargo delivery from Earth orbit to lunar orbit. Expendable and re-usable SEP profiles are considered. Flight control considerations are abstracted from recent papers by the author to describe how these influence SEP design and operations.

Analysis and design of lean direct injection fuel nozzles by eddy resolved turbulence simulation

NASA Astrophysics Data System (ADS)

Ryon, Jason Allen

Combustion systems in gas turbine engines are subjected to particular scrutiny in regards to the emissions which they produce. Of special interest are the emissions of Oxides of Nitrogen (NOx), which have a direct impact on air quality as well as health aspects. There is a need in the industry for elegant designs for these combustion systems which reduce the formation of NOx. The present study includes an in depth analysis of a state-of-the art prefilming airblast injector which is designed for achieving low NOx. The design has been studied through the use of turbulence resolving simulation to differentiate what is important for the design of this system. The OpenFOAM CFD software, with a Delayed Detached Eddy Simulation (DDES) model recently developed at Iowa State University, is shown to provide a suitable design tool which has been used to accurately predict a variety of parameters important to this combustion system. Of particular interest are the mixing characteristics of the atomizer, which have been studied through a series of CFD simulations including single-phase, multi-species, and multi-phase simulations. Turbulence simulations are validated by comparison to United Technologies Aerospace Systems (UTAS) data with air only. It is shown how DDES is able to capture the downstream mixing of air streams. Finally, a novel atomizer has been designed with these methods which is intended to promote thorough mixing. The CFD mixing characteristics are described and compared to the existing injector.

Lithium batteries. (Latest citations from the EI Compendex*plus database). Published Search

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1997-02-01

The bibliography contains citations concerning the design, development, and applications of lithium batteries. Topics include electrochemical aspects, cycling characteristics, performance evaluations, and applications in cardiac pacemaker devices. Batteries using organic compounds, chlorides, and metal sulfides are discussed. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

Lithium batteries. (Latest citations from the EI Compendex*plus database). Published Search

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-10-01

The bibliography contains citations concerning the design, development, and applications of lithium batteries. Topics include electrochemical aspects, cycling characteristics, performance evaluations, and applications in cardiac pacemaker devices. Batteries using organic compounds, chlorides, and metal sulfides are discussed. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

Observing System Simulation Experiments: An Overview

NASA Technical Reports Server (NTRS)

Prive, Nikki C.; Errico, Ronald M.

2016-01-01

An overview of Observing System Simulation Experiments (OSSEs) will be given, with focus on calibration and validation of OSSE frameworks. Pitfalls and practice will be discussed, including observation error characteristics, incestuousness, and experimental design. The potential use of OSSEs for investigation of the behaviour of data assimilation systems will be explored, including some results from experiments using the NASAGMAO OSSE.

Exercise prescription after fragility fracture in older adults: a scoping review

PubMed Central

Feehan, Lynne M.; Beck, Charlotte A.; Harris, Susan R.; MacIntyre, Donna L.; Li, Linda C.

2017-01-01

Purpose To identify and chart research literature on safety, efficacy or effectiveness of exercise prescription following fracture in older adults. Methods We conducted a systematic, research-user-informed, scoping review. The population of interest was adults aged ≥ 45 years with any fracture. ‘Exercise prescription’ included post-fracture therapeutic exercise, physical activity or rehabilitation interventions. Eligible designs included knowledge synthesis studies, primary interventional studies and observational studies. Trained reviewers independently evaluated citations for inclusion. Results A total of 9415 citations were reviewed with 134 citations (119 unique studies) identified: 13 knowledge syntheses, 95 randomized or controlled clinical trials, and 11 ‘other’ designs, representing 74 articles on lower extremity fractures, 34 on upper extremity, eight on vertebral, and three on mixed body region fractures. Exercise prescription characteristics were often missing or poorly described. Six general categories emerged describing exercise prescription characteristics: timing post-fracture, person prescribing, program design, functional focus, exercise script parameters and co-interventions. Upper extremity and ankle fracture studies focused on fracture healing or structural impairment outcomes, whereas hip fracture studies focused more on activity limitation outcomes. The variety of different outcome measures used made pooling or comparison of outcomes difficult. Conclusions There was insufficient information to identify evidence-informed parameters for safe and effective exercise prescription for older adults following fracture. Key gaps in the literature include limited numbers of studies on exercise prescription following vertebral fracture, poor delineation of effectiveness of different strategies for early post-fracture mobilization following upper extremity fracture, and inconsistent details of exercise prescription characteristics after lower extremity fracture. PMID:20967425

A study of microwave downcoverters operating in the K sub u band

NASA Technical Reports Server (NTRS)

Fellers, R. G.; Simpson, T. L.; Tseng, B.

1982-01-01

A computer program for parametric amplifier design is developed with special emphasis on practical design considerations for microwave integrated circuit degenerate amplifiers. Precision measurement techniques are developed to obtain a more realistic varactor equivalent circuit. The existing theory of a parametric amplifier is modified to include the equivalent circuit, and microwave properties, such as loss characteristics and circuit discontinuities are investigated.

Magnetron sputtering source

DOEpatents

Makowiecki, Daniel M.; McKernan, Mark A.; Grabner, R. Fred; Ramsey, Philip B.

1994-01-01

A magnetron sputtering source for sputtering coating substrates includes a high thermal conductivity electrically insulating ceramic and magnetically attached sputter target which can eliminate vacuum sealing and direct fluid cooling of the cathode assembly. The magnetron sputtering source design results in greater compactness, improved operating characteristics, greater versatility, and low fabrication cost. The design easily retrofits most sputtering apparatuses and provides for safe, easy, and cost effective target replacement, installation, and removal.

Effect of Peer-Led Team Learning (PLTL) on Student Achievement, Attitude, and Self-Concept in College General Chemistry in Randomized and Quasi Experimental Designs

ERIC Educational Resources Information Center

Chan, Julia Y. K.; Bauer, Christopher F.

2015-01-01

This study investigated exam achievement and affective characteristics of students in general chemistry in a fully-randomized experimental design, contrasting Peer-Led Team Learning (PLTL) participation with a control group balanced for time-on-task and study activity. This study population included two independent first-semester courses with…

A Survey of CAD/CAM Technology Applications in the U.S. Shipbuilding Industry

DTIC Science & Technology

1984-01-01

operation for drafting. Computer Aided Engineering (CAE) analysis is used primarily to determine the validity of design characteristics and produc- tion...include time standard generation, sea trial analysis , and group Systems integration While no systems surveyed Aided Design (CAD) is the technology... analysis . is the largest problem involving software packages. are truly integrated, many are interfaced. Computer most interfaced category with links

The Distributed Lambda (?) Model (DLM): A 3-D, Finite-Element Muscle Model Based on Feldman's ? Model; Assessment of Orofacial Gestures

ERIC Educational Resources Information Center

Nazari, Mohammad Ali; Perrier, Pascal; Payan, Yohan

2013-01-01

Purpose: The authors aimed to design a distributed lambda model (DLM), which is well adapted to implement three-dimensional (3-D), finite-element descriptions of muscles. Method: A muscle element model was designed. Its stress-strain relationships included the active force-length characteristics of the ? model along the muscle fibers, together…

Overview of NASA tire experimental programs

NASA Technical Reports Server (NTRS)

Tanner, J. A.

1983-01-01

Ongoing aircraft tire experimental programs are reported. These programs are designed to measure profile growth due to inflation pressure and vertical loading, contact pressures in the tire footprint, and a number of tire mechanical properties including spring, damping, and relaxation characteristics.

Orientation to Municipal Wastewater Treatment. Training Manual.

ERIC Educational Resources Information Center

Office of Water Program Operations (EPA), Cincinnati, OH. National Training and Operational Technology Center.

Introductory-level material on municipal wastewater treatment facilities and processes is presented. Course topics include sources and characteristics of municipal wastewaters; objectives of wastewater treatment; design, operation, and maintenance factors; performance testing; plant staffing; and laboratory considerations. Chapter topics include…

A source flow characteristic technique for the analysis of scramjet exhaust flow field

NASA Technical Reports Server (NTRS)

Delguidice, P.; Dash, S.; Kalben, P.

1974-01-01

The factors which influence the design and selection of a nozzle for a hypersonic scramjet are described. A two dimensional second-order characteristic procedure capable of analyzing the aerodynamic performance of typical nozzle configurations is presented. Equations of motion governing the two dimensional, axisymmetric, or axially expanding inviscid flow of a gas mixture, with frozen chemistry, are provided. Diagrams of the flow conditions for various configurations are included.

Report of the Working Design Group

NASA Technical Reports Server (NTRS)

1992-01-01

The engineering study group in the LOUISA workshop was responsible for producing a preliminary general design for an optical synthetic aperture telescope on the Moon. This design is intended to be a test case for focusing continuing design studies. The scope of the design included consideration of the array geometry, individual telescopes, metrology, site attributes, and construction. However, no attempt was made to go into further depth in the design than to cover the essential characteristics of the instrument. The starting point for the array design was the lunar optical array discussed by Burke (1985). His array geometry followed the design and correlation procedure of the 27-element Very Large Array (VLA) radio telescopes near Socorro, New Mexico.

An analytical procedure and automated computer code used to design model nozzles which meet MSFC base pressure similarity parameter criteria. [space shuttle

NASA Technical Reports Server (NTRS)

Sulyma, P. R.

1980-01-01

Fundamental equations and similarity definition and application are described as well as the computational steps of a computer program developed to design model nozzles for wind tunnel tests conducted to define power-on aerodynamic characteristics of the space shuttle over a range of ascent trajectory conditions. The computer code capabilities, a user's guide for the model nozzle design program, and the output format are examined. A program listing is included.

Modular space station phase B extension, preliminary system design. Volume 4: Subsystems analyses

NASA Technical Reports Server (NTRS)

Antell, R. W.

1972-01-01

The subsystems tradeoffs, analyses, and preliminary design results are summarized. Analyses were made of the structural and mechanical, environmental control and life support, electrical power, guidance and control, reaction control, information, and crew habitability subsystems. For each subsystem a summary description is presented including subsystem requirements, subsystem description, and subsystem characteristics definition (physical, performance, and interface). The major preliminary design data and tradeoffs or analyses are described in detail at each of the assembly levels.

Conceptual design of a piloted Mars sprint life support system

NASA Technical Reports Server (NTRS)

Cullingford, H. S.; Novara, M.

1988-01-01

This paper presents the conceptual design of a life support system sustaining a crew of six in a piloted Mars sprint. The requirements and constraints of the system are discussed along with its baseline performance parameters. An integrated operation is achieved with air, water, and waste processing and supplemental food production. The design philosophy includes maximized reliability considerations, regenerative operations, reduced expendables, and fresh harvest capability. The life support system performance will be described with characteristics of the associated physical-chemical subsystems and a greenhouse.

Sortie laboratory, phase B technical summary. [design and operational requirements

NASA Technical Reports Server (NTRS)

1973-01-01

The design and operational requirements which evolved from Sortie Lab (SL) analysis are summarized. A source of requirements for systems is given along with experimental support for the SL, baseline. Basic design data covered include: configuration definition, mission analysis, experimental integration, safety, and logistics. A technical summary outlines characteristics which reflect the influence of the growth in SL capability and the results of the mission and operational analysis. Each of the selected areas is described in terms of objectives, equipment, operational concept, and support requirements.

Design of Three-Dimensional Hypersonic Inlets with Rectangular to Elliptical Shape Transition

NASA Technical Reports Server (NTRS)

Smart, M. K.

1998-01-01

A methodology has been devised for the design of three-dimensional hypersonic inlets which include a rectangular to elliptical shape transition. This methodology makes extensive use of inviscid streamtracing techniques to generate a smooth shape transition from a rectangular-like capture to an elliptical throat. Highly swept leading edges and a significantly notched cowl enable use of these inlets in fixed geometry configurations. The design procedure includes a three dimensional displacement thickness calculation and uses established correlations to check for boundary layer separation due to shock wave interactions. Complete details of the design procedure are presented and the characteristics of a modular inlet with rectangular to elliptical shape transition and a design point of Mach 7.1 are examined. Comparison with a classical two-dimensional inlet optimized for maximum total pressure recovery indicates that this three-dimensional inlet demonstrates good performance even well below its design point.

Design, fabrication, and test of lightweight shell structure, phase 2

NASA Technical Reports Server (NTRS)

1974-01-01

A cylindrical shell skirt structure 4.57 m (180 in.) in diameter and 3.66 m (144 in.) high was subjected to a design and analysis study using a wide variety of structural materials and concepts. The design loading of 1225.8 N/cm (700 lb/in.) axial compression and 245.2 N/cm (140 lb/in.) torsion is representative of that expected on a typical space tug skirt section. Structural concepts evaluated included honeycomb sandwich, truss, isogrid, and skin/stringer/frame. The materials considered included a wide variety of structural metals as well as glass, graphite, and boron-reinforced composites. The most unique characteristic of the candidate designs is that they involve the use of very thin-gage material. Fabrication and structural test of small panels and components representative of many of the candidate designs served to demonstrate proposed fabrication techniques and to verify design and analysis methods.

Design and development of a structural mode control system

NASA Technical Reports Server (NTRS)

1977-01-01

A program was conducted to compile and document some of the existing information about the conceptual design, development, and tests of the B-1 structural mode control system (SMCS) and its impact on ride quality. This report covers the following topics: (1) Rationale of selection of SMCS to meet ride quality criteria versus basic aircraft stiffening. (2) Key considerations in designing an SMCS, including vane geometry, rate and deflection requirements, power required, compensation network design, and fail-safe requirements. (3) Summary of key results of SMCS vane wind tunnel tests. (4) SMCS performance. (5) SMCS design details, including materials, bearings, and actuators. (6) Results of qualification testing of SMCS on the "Iron Bird" flight control simulator, and lab qualification testing of the actuators. (7) Impact of SMCS vanes on engine inlet characteristics from wind tunnel tests.

Shop test of the 501F; A 150 MW combustion turbine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Entenmann, D.T.; North, W.E.; Fukue, I.

1991-10-01

The 501F is a 150 MW-class 60 Hz engine jointly developed by Westinghouse Electric Corporation and Mitsubishi Heavy Industries, Ltd. This paper describes the full-load shop test program for the prototype engine, as carried out in Takasago, Japan. The shop test included a full range of operating conditions, from startup through full load at the 1260{degrees} C (2300{degrees} F) design turbine inlet temperature. The engine was prepared with more than 1500 instrumentation points to monitor flow path characteristics, metal temperatures, displacements, pressures, cooling circuit characteristics, strains, sound pressure levels, and exhaust emissions. The results of this shop test indicate themore » new 501F engine design and development effort to be highly successful. The engine exceeds power and overall efficiency expectations, thus verifying the new concepts and design improvements.« less

Design and Optimization Method of a Two-Disk Rotor System

NASA Astrophysics Data System (ADS)

Huang, Jingjing; Zheng, Longxi; Mei, Qing

2016-04-01

An integrated analytical method based on multidisciplinary optimization software Isight and general finite element software ANSYS was proposed in this paper. Firstly, a two-disk rotor system was established and the mode, humorous response and transient response at acceleration condition were analyzed with ANSYS. The dynamic characteristics of the two-disk rotor system were achieved. On this basis, the two-disk rotor model was integrated to the multidisciplinary design optimization software Isight. According to the design of experiment (DOE) and the dynamic characteristics, the optimization variables, optimization objectives and constraints were confirmed. After that, the multi-objective design optimization of the transient process was carried out with three different global optimization algorithms including Evolutionary Optimization Algorithm, Multi-Island Genetic Algorithm and Pointer Automatic Optimizer. The optimum position of the two-disk rotor system was obtained at the specified constraints. Meanwhile, the accuracy and calculation numbers of different optimization algorithms were compared. The optimization results indicated that the rotor vibration reached the minimum value and the design efficiency and quality were improved by the multidisciplinary design optimization in the case of meeting the design requirements, which provided the reference to improve the design efficiency and reliability of the aero-engine rotor.

Aerodynamic characteristics of some lifting reentry concepts applicable to transatmospheric vehicle design studies

NASA Technical Reports Server (NTRS)

Spearman, M. L.

1984-01-01

The aerodynamic characteristics of some lifting reentry concepts are examined with a view to the applicability of such concepts to the design of possible transatmospheric vehicles (TAV). A considerable amount of research has been done in past years with vehicle concepts suitable for manned atmospheric-entry, atmospheric flight, and landing. Some of the features of these concepts that permit flight in or out of the atmosphere with maneuver capability should be useful in the mission requirements of TAV's. The concepts illustrated include some hypersonic-body shapes with and without variable geometry surfaces, and a blunt lifting-body configuration. The merits of these concepts relative to the aerodynamic behavior of a TAV are discussed.

Atomization characteristics of swirl injector sprays

NASA Technical Reports Server (NTRS)

Feikema, Douglas A.

1996-01-01

Stable combustion within rocket engines is a continuing concern for designers of rocket engine systems. The swirl-coaxial injector has demonstrated effectiveness in achieving atomization and mixing, and therefore stable combustion. Swirl-coaxial injector technology is being deployed in the American RL1OA rocket design and Russian engine systems already make wide spread use of this technology. The present requirement for swirl injector research is derived from NASA's current Reusable Launch Vehicle (RLV) technology program. This report describes some of the background and literature on this topic including drop size measurements, comparison with theoretical predictions, the effect of surface tension on the atomization process, and surface wave characteristics of liquid film at the exit of the injector.

Widened photonic functionality of asymmetric high-index contrast/photonic crystal gratings

NASA Astrophysics Data System (ADS)

Nguyen, Hai Son; Dubois, Florian; Letartre, Xavier; Leclercq, Jean-Louis; Seassal, Christian; Viktorovitch, Pierre

2016-03-01

In this presentation we emphasize that, within the variety of parameters usable for the design of HCGs, the transverse (vertical) symmetry properties of HCGs provide a power-full joystick for the dispersion engineering of guided mode resonances. We concentrate on asymmetric HCGs designed to accommodate guided mode resonances with ultra-flat zero-curvature dispersion characteristics (or photons with ultra-heavy effective mass), as well as with Dirac cone shaped linear dispersion characteristics. Examples of the great potential of this family of asymmetric HCGs will include the development of a platform for polaritonic devices and the production of micro-lasers particularly suited for hybrid III-V / silicon heterogeneous photonic integration, along CMOS compatible technological schemes.

Multimode analysis of highly tunable, quantum cascade powered, circular graphene spaser

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jayasekara, Charith, E-mail: charith.jayasekara@monash.edu; Premaratne, Malin; Stockman, Mark I.

2015-11-07

We carried out a detailed analysis of a circular graphene spaser made of a circular graphene flake and a quantum cascade well structure. Owing to unique properties of graphene and quantum cascade well structure, the proposed design shows high mechanical and thermal stability and low optical losses. Additionally, operation characteristics of the model are analysed and tunability of the device is demonstrated. Some advantages of the proposed design include compact size, lower power operation, and the ability to set the operating wavelength over a wide range from Mid-IR to Near-IR. Thus, it can have wide spread applications including designing ofmore » ultracompact and ultrafast devices, nanoscopy and biomedical applications.« less

Seal material development test program

NASA Technical Reports Server (NTRS)

1971-01-01

A program designed to characterize an experimental fluoroelastomer material designated AF-E-124D, is examined. Tests conducted include liquid nitrogen load compression tests, flexure tests and valve seal tests, ambient and elevated temperature compression set tests, and cleaning and flushing fluid exposure tests. The results of these tests indicate the AF-E-124D is a good choice for a cryogenic seal, since it exhibits good low temperature sealing characteristics and resistance to permanent set. The status of this material as an experimental fluorelastomer is stressed and recommended. Activity includes definition and control of critical processing to ensure consistent material properties. Design, fabrication and test of this and other materials is recommended in valve and static seal applications.

Preliminary design of 1 kW bipolar Ni-MH battery for LEO-satellite application

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cole, J.H.; Reisner, D.E.; Klein, M.G.

1996-12-31

Electro Energy, Inc. (EEI) is developing a bipolar nickel-metal hydride rechargeable battery based upon the use of stackable wafer cells. The key to viable bipolar operation has been this unique modular (unitized) approach. The patented unit wafer-cell construct exploits the chemical and thermal properties of a proprietary electrically conductive plastic film. Characteristic of bipolar batteries, current flows across the cell interfaces-perpendicular to the electrode plane. EEI has recently contracted with NASA Lewis Research Center (LeRC) to develop an optimized design 1 kW flightweight battery, for low-earth-orbit (LEO) satellite applications, over a 4-year period with a deliverable flightweight design package. Themore » contract includes an option for EEI to deliver up to three flight quality batteries in an 18-month follow-on program. NASA LeRC has promulgated that the program steps include the design, fabrication, and evaluation of four evolutionary stages of the final battery design which have been designated Preliminary, Improved, Optimized, and Flightweight Design. Initial results from the Preliminary Stage are presented including a 1 kW battery design, thermal design, parameter study, and component development in subscale bipolar batteries.« less

Development of a rotary power transformer and inverter drive for spacecraft

NASA Technical Reports Server (NTRS)

Mclyman, W. T.; Bridgeforth, A. O.

1983-01-01

Many future satellites and spacecraft with spun and despun configurations will require the transfer of power across rotating interfaces in lieu of slip-rings and/or flexures. This is particularly true of spacecraft that have to demonstrate a long life expectancy. The rotary transformer has the desirable characteristics of high reliability and low noise, which qualify it as a potential replacement for slip rings. Development of a rotary power transformer follows the successful completion of a task to develop rotary signal-level transformers for the Galileo Spacecraft Project. The physical configuration of a rotary power transformer has a significant effect on its magnetic and electrical characteristics and therefore impacts the design of the dc/ac inverter driver. Important characteristics addressed during this development effort include: operating frequency, efficiency, transformer gap size, leakage inductance, and leakage flux. A breadboard inverter and rotary transformer were designed, fabricated and tested.

Transmittance properties of one dimensional ternary nanocomposite photonic crystals

NASA Astrophysics Data System (ADS)

Elsayed, Hussein A.

2018-03-01

In the present work, we have theoretically investigated the transmittance characteristics of one dimensional ternary photonic crystals that containing a nanocomposite layer. The nanocomposite layer was designed from metallic nanoparticles of (Ag) in a transparent matrix of a dielectric material (MgF2). The numerical results are obtained based on the theoretical modeling of the characteristic matrix method and Maxwell-Garnett model. The investigated results demonstrate the significant effect of the volume fraction of the nanoparticles on the effective permittivity of the nanocomposite material as well as the transmission characteristics of our design. Moreover, the roles played by other parameters such as the thickness of the nanocomposite layer, the permittivity of the host dielectric material and the spherical radius of the nanoparticles are included her. The proposed structure could be promising for many applications such as THz optical filters, reflectors and optical switches.

A Spherical Torus Nuclear Fusion Reactor Space Propulsion Vehicle Concept for Fast Interplanetary Travel

NASA Technical Reports Server (NTRS)

Williams, Craig H.; Borowski, Stanley K.; Dudzinski, Leonard A.; Juhasz, Albert J.

1998-01-01

A conceptual vehicle design enabling fast outer solar system travel was produced predicated on a small aspect ratio spherical torus nuclear fusion reactor. Initial requirements were for a human mission to Saturn with a greater than 5% payload mass fraction and a one way trip time of less than one year. Analysis revealed that the vehicle could deliver a 108 mt crew habitat payload to Saturn rendezvous in 235 days, with an initial mass in low Earth orbit of 2,941 mt. Engineering conceptual design, analysis, and assessment was performed on all ma or systems including payload, central truss, nuclear reactor (including divertor and fuel injector), power conversion (including turbine, compressor, alternator, radiator, recuperator, and conditioning), magnetic nozzle, neutral beam injector, tankage, start/re-start reactor and battery, refrigeration, communications, reaction control, and in-space operations. Detailed assessment was done on reactor operations, including plasma characteristics, power balance, power utilization, and component design.

The Application of the NFW Design Philosophy to the HSR Arrow Wing Configuration

NASA Technical Reports Server (NTRS)

Bauer, Steven X. S.; Krist, Steven E.

1999-01-01

The Natural Flow Wing design philosophy was developed for improving performance characteristics of highly-swept fighter aircraft at cruise and maneuvering conditions across the Mach number range (from Subsonic through Supersonic). The basic philosophy recognizes the flow characteristics that develop on highly swept wings and contours the surface to take advantage of those flow characteristics (e.g., forward facing surfaces in low pressure regions and aft facing surfaces in higher pressure regions for low drag). Because the wing leading edge and trailing edge have multiple sweep angles and because of shocks generated on nacelles and diverters, a viscous code was required to accurately define the surface pressure distributions on the wing. A method of generating the surface geometry to take advantage of those surface pressures (as well as not violating any structural constraints) was developed and the resulting geometries were analyzed and compared to a baseline configuration. This paper will include discussions of the basic Natural Flow Wing design philosophy, the application of the philosophy to an HSCT vehicle, and preliminary wind-tunnel assessment of the NFW HSCT vehicle.

Methods for determining the genetic affinity of microorganisms and viruses

NASA Technical Reports Server (NTRS)

Fox, George E. (Inventor); Willson, III, Richard C. (Inventor); Zhang, Zhengdong (Inventor)

2012-01-01

Selecting which sub-sequences in a database of nucleic acid such as 16S rRNA are highly characteristic of particular groupings of bacteria, microorganisms, fungi, etc. on a substantially phylogenetic tree. Also applicable to viruses comprising viral genomic RNA or DNA. A catalogue of highly characteristic sequences identified by this method is assembled to establish the genetic identity of an unknown organism. The characteristic sequences are used to design nucleic acid hybridization probes that include the characteristic sequence or its complement, or are derived from one or more characteristic sequences. A plurality of these characteristic sequences is used in hybridization to determine the phylogenetic tree position of the organism(s) in a sample. Those target organisms represented in the original sequence database and sufficient characteristic sequences can identify to the species or subspecies level. Oligonucleotide arrays of many probes are especially preferred. A hybridization signal can comprise fluorescence, chemiluminescence, or isotopic labeling, etc.; or sequences in a sample can be detected by direct means, e.g. mass spectrometry. The method's characteristic sequences can also be used to design specific PCR primers. The method uniquely identifies the phylogenetic affinity of an unknown organism without requiring prior knowledge of what is present in the sample. Even if the organism has not been previously encountered, the method still provides useful information about which phylogenetic tree bifurcation nodes encompass the organism.

Man-machine interface analysis of the flight design system

NASA Technical Reports Server (NTRS)

Ramsey, H. R.; Atwood, M. E.; Willoughby, J. K.

1978-01-01

The objective of the current effort was to perform a broad analysis of the human factors issues involved in the design of the Flight Design System (FDS). The analysis was intended to include characteristics of the system itself, such as: (1) basic structure and functional capabilities of FDS; (2) user backgrounds, capabilities, and possible modes of use; (3) FDS interactive dialogue, problem solving aids; (4) system data management capabilities; and to include, as well, such system related matters as: (1) flight design team structure; (2) roles of technicians; (3) user training; and (4) methods of evaluating system performance. Wherever possible, specific recommendations are made. In other cases, the issues which seem most important are identified. In some cases, additional analyses or experiments which might provide resolution are suggested.

47 CFR 97.121 - Restricted operation.

Code of Federal Regulations, 2013 CFR

2013-10-01

... station causes general interference to the reception of transmissions from stations operating in the domestic broadcast service when receivers of good engineering design, including adequate selectivity characteristics, are used to receive such transmissions, and this fact is made known to the amateur station...

47 CFR 97.121 - Restricted operation.

Code of Federal Regulations, 2012 CFR

2012-10-01

... station causes general interference to the reception of transmissions from stations operating in the domestic broadcast service when receivers of good engineering design, including adequate selectivity characteristics, are used to receive such transmissions, and this fact is made known to the amateur station...

47 CFR 97.121 - Restricted operation.

Code of Federal Regulations, 2014 CFR

2014-10-01

... station causes general interference to the reception of transmissions from stations operating in the domestic broadcast service when receivers of good engineering design, including adequate selectivity characteristics, are used to receive such transmissions, and this fact is made known to the amateur station...

47 CFR 97.121 - Restricted operation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... station causes general interference to the reception of transmissions from stations operating in the domestic broadcast service when receivers of good engineering design, including adequate selectivity characteristics, are used to receive such transmissions, and this fact is made known to the amateur station...

47 CFR 97.121 - Restricted operation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... station causes general interference to the reception of transmissions from stations operating in the domestic broadcast service when receivers of good engineering design, including adequate selectivity characteristics, are used to receive such transmissions, and this fact is made known to the amateur station...

10 CFR 61.13 - Technical analyses.

Code of Federal Regulations, 2014 CFR

2014-01-01

... REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR LAND DISPOSAL OF RADIOACTIVE WASTE Licenses § 61... characteristics and design features in isolating and segregating the wastes. The analyses must clearly demonstrate... inadvertent intrusion must include demonstration that there is reasonable assurance the waste classification...

10 CFR 61.13 - Technical analyses.

Code of Federal Regulations, 2011 CFR

2011-01-01

... REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR LAND DISPOSAL OF RADIOACTIVE WASTE Licenses § 61... characteristics and design features in isolating and segregating the wastes. The analyses must clearly demonstrate... inadvertent intrusion must include demonstration that there is reasonable assurance the waste classification...

10 CFR 61.13 - Technical analyses.

Code of Federal Regulations, 2013 CFR

2013-01-01

... REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR LAND DISPOSAL OF RADIOACTIVE WASTE Licenses § 61... characteristics and design features in isolating and segregating the wastes. The analyses must clearly demonstrate... inadvertent intrusion must include demonstration that there is reasonable assurance the waste classification...

10 CFR 61.13 - Technical analyses.

Code of Federal Regulations, 2012 CFR

2012-01-01

... REGULATORY COMMISSION (CONTINUED) LICENSING REQUIREMENTS FOR LAND DISPOSAL OF RADIOACTIVE WASTE Licenses § 61... characteristics and design features in isolating and segregating the wastes. The analyses must clearly demonstrate... inadvertent intrusion must include demonstration that there is reasonable assurance the waste classification...

Calculation and use of an environment's characteristic software metric set

NASA Technical Reports Server (NTRS)

Basili, Victor R.; Selby, Richard W., Jr.

1985-01-01

Since both cost/quality and production environments differ, this study presents an approach for customizing a characteristic set of software metrics to an environment. The approach is applied in the Software Engineering Laboratory (SEL), a NASA Goddard production environment, to 49 candidate process and product metrics of 652 modules from six (51,000 to 112,000 lines) projects. For this particular environment, the method yielded the characteristic metric set (source lines, fault correction effort per executable statement, design effort, code effort, number of I/O parameters, number of versions). The uses examined for a characteristic metric set include forecasting the effort for development, modification, and fault correction of modules based on historical data.

Lateral-directional aerodynamic characteristics of light, twin-engine, propeller driven airplanes

NASA Technical Reports Server (NTRS)

Wolowicz, C. H.; Yancey, R. B.

1972-01-01

Analytical procedures and design data for predicting the lateral-directional static and dynamic stability and control characteristics of light, twin engine, propeller driven airplanes for propeller-off and power-on conditions are reported. Although the consideration of power effects is limited to twin engine airplanes, the propeller-off considerations are applicable to single engine airplanes as well. The procedures are applied to a twin engine, propeller driven, semi-low-wing airplane in the clean configuration through the linear lift range. The calculated derivative characteristics are compared with wind tunnel and flight data. Included in the calculated characteristics are the spiral mode, roll mode, and Dutch roll mode over the speed range of the airplane.

Radio-wave propagation for space communications systems

NASA Technical Reports Server (NTRS)

Ippolito, L. J.

1981-01-01

The most recent information on the effects of Earth's atmosphere on space communications systems is reviewed. The design and reliable operation of satellite systems that provide the many applications in space which rely on the transmission of radio waves for communications and scientific purposes are dependent on the propagation characteristics of the transmission path. The presence of atmospheric gases, clouds, fog, precipitation, and turbulence causes uncontrolled variations in the signal characteristics. These variations can result in a reduction of the quality and reliability of the transmitted information. Models and other techniques are used in the prediction of atmospheric effects as influenced by frequency, geography, elevation angle, and type of transmission. Recent data on performance characteristics obtained from direct measurements on satellite links operating to above 30 GHz have been reviewed. Particular emphasis has been placed on the effects of precipitation on the Earth/space path, including rain attenuation, and ice particle depolarization. Other factors are sky noise, antenna gain degradation, scintillations, and bandwidth coherence. Each of the various propagation factors has an effect on design criteria for communications systems. These criteria include link reliability, power margins, noise contribution, modulation and polarization factors, channel cross talk, error rate, and bandwidth limitations.

Heterogeneity in application, design, and analysis characteristics was found for controlled before-after and interrupted time series studies included in Cochrane reviews.

PubMed

Polus, Stephanie; Pieper, Dawid; Burns, Jacob; Fretheim, Atle; Ramsay, Craig; Higgins, Julian P T; Mathes, Tim; Pfadenhauer, Lisa M; Rehfuess, Eva A

2017-11-01

The aim of the study was to examine the application, design, and analysis characteristics of controlled before-after (CBA) and interrupted time series (ITS) studies and their use in Cochrane reviews. We searched the Cochrane library for reviews including these study designs from May 2012 to March 2015 and purposively selected, where available, two reviews each across 10 prespecified intervention types. We randomly selected two CBA and two ITS studies from each review. Two researchers independently extracted information from the studies and the respective reviews. Sixty-nine reviews considered CBA and ITS studies for inclusion. We analyzed 21 CBA and 16 ITS studies from 11 to 8 reviews, respectively. Cochrane reviews inconsistently defined and labeled CBA and ITS studies. Many studies did not meet the Cochrane definition or the minimum criteria provided by Cochrane Effective Practice and Organisation of Care. The studies present a heterogeneous set of study features and applied a large variety of analyses. While CBA and ITS studies represent important study designs to evaluate the effects of interventions, especially on a population or organizational level, unclear study design features challenge unequivocal classification and appropriate use. We discuss options for more specific definitions and explicit criteria for CBA and ITS studies. Copyright © 2017 Elsevier Inc. All rights reserved.

Variability in Criteria for Emergency Medical Services Routing of Acute Stroke Patients to Designated Stroke Center Hospitals.

PubMed

Dimitrov, Nikolay; Koenig, William; Bosson, Nichole; Song, Sarah; Saver, Jeffrey L; Mack, William J; Sanossian, Nerses

2015-09-01

Comprehensive stroke systems of care include routing to the nearest designated stroke center hospital, bypassing non-designated hospitals. Routing protocols are implemented at the state or county level and vary in qualification criteria and determination of destination hospital. We surveyed all counties in the state of California for presence and characteristics of their prehospital stroke routing protocols. Each county's local emergency medical services agency (LEMSA) was queried for the presence of a stroke routing protocol. We reviewed these protocols for method of stroke identification and criteria for patient transport to a stroke center. Thirty-three LEMSAs serve 58 counties in California with populations ranging from 1,175 to nearly 10 million. Fifteen LEMSAs (45%) had stroke routing protocols, covering 23 counties (40%) and 68% of the state population. Counties with protocols had higher population density (1,500 vs. 140 persons per square mile). In the six counties without designated stroke centers, patients meeting criteria were transported out of county. Stroke identification in the field was achieved using the Cincinnati Prehospital Stroke Screen in 72%, Los Angeles Prehospital Stroke Screen in 7% and a county-specific protocol in 22%. California EMS prehospital acute stroke routing protocols cover 68% of the state population and vary in characteristics including activation by symptom onset time and destination facility features, reflecting matching of system design to local geographic resources.

A socio-environmental monitoring system for a UNESCO biosphere reserve.

PubMed

Lowell, Kim

2017-11-03

To identify potentially critical changes in an area's ongoing ability to produce multiple ecosystem services, a monitoring system was designed and implemented for the Mornington Peninsula and Westernport Biosphere Reserve in southeast Australia. The system is underpinned by an "environmental vital signs" (EVS) approach that was adopted to provide early warning of critical changes in human and natural characteristics of the area. The six themes monitored are non-coastal water, land including vegetation, biodiversity, natural heritage, built environment (including human population and economic activity), and coasts. These are monitored for the entire area, and each of its five constituent town council areas. After a critical change in any of these is identified, further investigation is required to identify causal factors and, if required, determine an appropriate response. The system relies on data available from external (third-party) organisations to monitor the natural and human characteristics of the area that were important in its designation as a UNESCO biosphere reserve. Strengths and weaknesses associated with the use of third-party data are discussed. These include adoption of baseline years and data reporting periods for different factors, costs, and data quality.

Feasibility of a wireless gamma probe in radioguided surgery.

PubMed

Park, Hye Min; Joo, Koan Sik

2016-06-21

Radioguided surgery through the use of a gamma probe is an established practice, and has been widely applied in the case of sentinel lymph node biopsies. A wide range of intraoperative gamma probes is commercially available. The primary characteristics of the gamma probes include their sensitivity, spatial resolution, and energy resolution. We present the results obtained from a prototype of a new wireless gamma probe. This prototype is composed of a 20 mm thick cerium-doped gadolinium aluminum gallium garnet (Ce:GAGG) inorganic scintillation crystal from Furukawa Denshi and a Hamamatsu S12572-100C multi-pixel photon counter equipped with a designed electronics. The measured performance characteristics include the energy resolution, energy linearity, angular aperture, spatial resolution and sensitivity. Measurements were carried out using (57)Co, (133)Ba, (22)Na, and (137)Cs sources. The energy resolutions for 0.122 and 0.511 MeV were 17.2% and 6.9%, respectively. The designed prototype consumes an energy of approximately 4.4 W, weighs about 310 g (including battery) having a dimension of 20 mm (D)  ×  130 mm (L).

Feasibility of a wireless gamma probe in radioguided surgery

NASA Astrophysics Data System (ADS)

Park, Hye Min; Joo, Koan Sik

2016-06-01

Radioguided surgery through the use of a gamma probe is an established practice, and has been widely applied in the case of sentinel lymph node biopsies. A wide range of intraoperative gamma probes is commercially available. The primary characteristics of the gamma probes include their sensitivity, spatial resolution, and energy resolution. We present the results obtained from a prototype of a new wireless gamma probe. This prototype is composed of a 20 mm thick cerium-doped gadolinium aluminum gallium garnet (Ce:GAGG) inorganic scintillation crystal from Furukawa Denshi and a Hamamatsu S12572-100C multi-pixel photon counter equipped with a designed electronics. The measured performance characteristics include the energy resolution, energy linearity, angular aperture, spatial resolution and sensitivity. Measurements were carried out using 57Co, 133Ba, 22Na, and 137Cs sources. The energy resolutions for 0.122 and 0.511 MeV were 17.2% and 6.9%, respectively. The designed prototype consumes an energy of approximately 4.4 W, weighs about 310 g (including battery) having a dimension of 20 mm (D)  ×  130 mm (L).

Preliminary economic evaluation of the use of graphite composite materials in surface transportation, phase 1 results

NASA Technical Reports Server (NTRS)

1977-01-01

Composite materials are discussed with emphasis on the identification of the characteristics of those materials that make them attractive for use in surface transportation. Potential uses of graphite composites are given including automotive applications and the effects of materials substitution on vehicle characteristics and performance. Preliminary estimates of the economic effects of the use of graphite composite materials on vehicle manufacturers and consumers are included. The combined impact on the national economy of vehicle design changes to meet mandated fuel efficiency requirements and the extensive use of graphite composite materials in the automotive industry is considered.

"Bimodal" Nuclear Thermal Rocket (BNTR) Propulsion for Future Human Mars Exploration Missions

NASA Technical Reports Server (NTRS)

Borowski, Stanley K.

2004-01-01

The Nuclear Thermal Rocket (NTR) Propulsion program is discussed. The Rover/NERVA program from 1959-1972 is compared with the current program. A key technology description, bimodal vehicle design for Mars Cargo and the crew transfer vehicle with inflatable module and artificial gravity capability, including diagrams are included. The LOX-Augmented NTR concept/operational features and characteristics are discussed.

Scaled Tank Test Design and Results for the Aquantis 2.5 MW Ocean Current Generation Device

DOE Data Explorer

Swales, Henry; Kils, Ole; Coakley, David B.; Sites, Eric; Mayer, Tyler

2015-06-03

Aquantis 2.5 MW Ocean Current Generation Device, Tow Tank Dynamic Rig Structural Analysis Results. This is the detailed documentation for scaled device testing in a tow tank, including models, drawings, presentations, cost of energy analysis, and structural analysis. This dataset also includes specific information on drivetrain, roller bearing, blade fabrication, mooring, and rotor characteristics.

Practical characteristics of adaptive design in phase 2 and 3 clinical trials.

PubMed

Sato, A; Shimura, M; Gosho, M

2018-04-01

Adaptive design methods are expected to be ethical, reflect real medical practice, increase the likelihood of research and development success and reduce the allocation of patients into ineffective treatment groups by the early termination of clinical trials. However, the comprehensive details regarding which types of clinical trials will include adaptive designs remain unclear. We examined the practical characteristics of adaptive design used in clinical trials. We conducted a literature search of adaptive design clinical trials published from 2012 to 2015 using PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials, with common search terms related to adaptive design. We systematically assessed the types and characteristics of adaptive designs and disease areas employed in the adaptive design trials. Our survey identified 245 adaptive design clinical trials. The number of trials by the publication year increased from 2012 to 2013 and did not greatly change afterwards. The most frequently used adaptive design was group sequential design (n = 222, 90.6%), especially for neoplasm or cardiovascular disease trials. Among the other types of adaptive design, adaptive dose/treatment group selection (n = 21, 8.6%) and adaptive sample-size adjustment (n = 19, 7.8%) were frequently used. The adaptive randomization (n = 8, 3.3%) and adaptive seamless design (n = 6, 2.4%) were less frequent. Adaptive dose/treatment group selection and adaptive sample-size adjustment were frequently used (up to 23%) in "certain infectious and parasitic diseases," "diseases of nervous system," and "mental and behavioural disorders" in comparison with "neoplasms" (<6.6%). For "mental and behavioural disorders," adaptive randomization was used in two trials of eight trials in total (25%). Group sequential design and adaptive sample-size adjustment were used frequently in phase 3 trials or in trials where study phase was not specified, whereas the other types of adaptive designs were used more in phase 2 trials. Approximately 82% (202 of 245 trials) resulted in early termination at the interim analysis. Among the 202 trials, 132 (54% of 245 trials) had fewer randomized patients than initially planned. This result supports the motive to use adaptive design to make study durations shorter and include a smaller number of subjects. We found that adaptive designs have been applied to clinical trials in various therapeutic areas and interventions. The applications were frequently reported in neoplasm or cardiovascular clinical trials. The adaptive dose/treatment group selection and sample-size adjustment are increasingly common, and these adaptations generally follow the Food and Drug Administration's (FDA's) recommendations. © 2017 John Wiley & Sons Ltd.

Magnetron sputtering source

DOEpatents

Makowiecki, D.M.; McKernan, M.A.; Grabner, R.F.; Ramsey, P.B.

1994-08-02

A magnetron sputtering source for sputtering coating substrates includes a high thermal conductivity electrically insulating ceramic and magnetically attached sputter target which can eliminate vacuum sealing and direct fluid cooling of the cathode assembly. The magnetron sputtering source design results in greater compactness, improved operating characteristics, greater versatility, and low fabrication cost. The design easily retrofits most sputtering apparatuses and provides for safe, easy, and cost effective target replacement, installation, and removal. 12 figs.

Pulsed ultrasonic instruments for monitoring the strength of materials

NASA Astrophysics Data System (ADS)

Korolev, Mikhail Viktorovich; Starikov, Boris Pavlovich; Karpel'Son, Arkadii Efimovich

The book is concerned with various aspects of the design of portable instruments for the ultrasonic monitoring of the strength and ductile characteristics of structural materials, including metals, alloys, and ceramics. Particular attention is given to methods for increasing the accuracy of the instruments while reducing their size, which is particularly important in the design of miniature instruments for the real-time monitoring of machines, mechanisms, and structures during operation.

Terrier Black Brant VC design characteristics and program status. [rocket development

NASA Technical Reports Server (NTRS)

Payne, B. R.; Mayo, E. E.

1979-01-01

In the present paper, the design analysis of the Terrier-Black Brant VC, representing the latest addition to the Black Brant rocket family, is discussed, including the aerodynamic, structural, thermal, and operational aspects. An appreciable increase in apogee, as compared to the BBVC and Nike/BBVC, is achieved without any modifications to the well-proven BBV motor or degradation of the thermal or dynamic flight environment.

How scientific experiments are designed: Problem solving in a knowledge-rich, error-rich environment

NASA Astrophysics Data System (ADS)

Baker, Lisa M.

While theory formation and the relation between theory and data has been investigated in many studies of scientific reasoning, researchers have focused less attention on reasoning about experimental design, even though the experimental design process makes up a large part of real-world scientists' reasoning. The goal of this thesis was to provide a cognitive account of the scientific experimental design process by analyzing experimental design as problem-solving behavior (Newell & Simon, 1972). Three specific issues were addressed: the effect of potential error on experimental design strategies, the role of prior knowledge in experimental design, and the effect of characteristics of the space of alternate hypotheses on alternate hypothesis testing. A two-pronged in vivo/in vitro research methodology was employed, in which transcripts of real-world scientific laboratory meetings were analyzed as well as undergraduate science and non-science majors' design of biology experiments in the psychology laboratory. It was found that scientists use a specific strategy to deal with the possibility of error in experimental findings: they include "known" control conditions in their experimental designs both to determine whether error is occurring and to identify sources of error. The known controls strategy had not been reported in earlier studies with science-like tasks, in which participants' responses to error had consisted of replicating experiments and discounting results. With respect to prior knowledge: scientists and undergraduate students drew on several types of knowledge when designing experiments, including theoretical knowledge, domain-specific knowledge of experimental techniques, and domain-general knowledge of experimental design strategies. Finally, undergraduate science students generated and tested alternates to their favored hypotheses when the space of alternate hypotheses was constrained and searchable. This result may help explain findings of confirmation bias in earlier studies using science-like tasks, in which characteristics of the alternate hypothesis space may have made it unfeasible for participants to generate and test alternate hypotheses. In general, scientists and science undergraduates were found to engage in a systematic experimental design process that responded to salient features of the problem environment, including the constant potential for experimental error, availability of alternate hypotheses, and access to both theoretical knowledge and knowledge of experimental techniques.

Educating educators about alcoholism and drug addiction: the role of employee assistance programmes.

PubMed

Van den Bergh, N

1990-01-01

The historical development of employee assistance programmes (EAPs) from occupational alcoholism programmes is outlined. Services for the three prevention levels of a 'broad brush' programme are described. The 'at-risk' characteristics of academia in potentiating alcoholism and addiction are noted, including several intrinsic characteristics of academics which could predispose to substance abuse. Ways in which EAPs enhance organizational goals are noted and several crucial steps in designing an academic EAP are suggested.

The distributed lambda (λ) model (DLM): a 3-D, finite-element muscle model based on Feldman's λ model; assessment of orofacial gestures.

PubMed

Nazari, Mohammad Ali; Perrier, Pascal; Payan, Yohan

2013-12-01

The authors aimed to design a distributed lambda model (DLM), which is well adapted to implement three-dimensional (3-D), finite-element descriptions of muscles. A muscle element model was designed. Its stress-strain relationships included the active force-length characteristics of the λ model along the muscle fibers, together with the passive properties of muscle tissues in the 3-D space. The muscle element was first assessed using simple geometrical representations of muscles in the form of rectangular bars. It was then included in a 3-D face model, and its impact on lip protrusion was compared with the impact of a Hill-type muscle model. The force-length characteristic associated with the muscle elements matched well with the invariant characteristics of the λ model. The impact of the passive properties was assessed. Isometric force variation and isotonic displacements were modeled. The comparison with a Hill-type model revealed strong similarities in terms of global stress and strain. The DLM accounted for the characteristics of the λ model. Biomechanically, no clear differences were found between the DLM and a Hill-type model. Accurate evaluations of the λ model, based on the comparison between data and simulations, are now possible with 3-D biomechanical descriptions of the speech articulators because of the DLM.

Trauma systems and the costs of trauma care.

PubMed Central

Goldfarb, M G; Bazzoli, G J; Coffey, R M

1996-01-01

OBJECTIVE. This study examines the cost of providing trauma services in trauma centers organized by publicly administered trauma systems, compared to hospitals not part of a formal trauma system. DATA SOURCES AND STUDY SETTING. Secondary administrative discharge abstracts for a national sample of severely injured trauma patients in 44 trauma centers and 60 matched control hospitals for the year 1987 were used. STUDY DESIGN. Retrospective univariate and multivariate analyses were conducted to examine the impact of formal trauma systems and trauma center designation on the costs of treating trauma patients. Key dependent variables included length of stay, charge per day per patient, and charge per hospital stay. Key impact variables were type of trauma system and level of trauma designation. Control variables included patient, hospital, and community characteristics. DATA COLLECTION/EXTRACTION METHODS. Data were selected for hospitals based on (1) a large national hospital discharge database, the Hospital Cost and Utilization Project, 1980-1987 (HCUP-2) and (2) a special survey of trauma systems and trauma designation undertaken by the Hospital Research and Educational Trust of the American Hospital Association. PRINCIPAL FINDINGS. The results show that publicly designated Level I trauma centers, which are the focal point of most trauma systems, have the highest charge per case, the highest average charge per day, and similar or longer average lengths of stay than other hospitals. These findings persist after controlling for patient injury and health status, and for demographic characteristics and hospital and community characteristics. CONCLUSIONS. Prior research shows that severely injured trauma patients have greater chances of survival when treated in specialized trauma centers. However, findings here should be of concern to the many states developing trauma systems since the high costs of Level I centers support limiting the number of centers designated at this level and/or reconsidering the requirements placed on these centers. PMID:8617611

Characteristics of suspended and streambed sediment within constructed chutes and the main channel at Upper Hamburg and Glovers Point Bends, Missouri River, Nebraska, 2008

USGS Publications Warehouse

Woodward, Brenda K.; Rus, David L.

2011-01-01

The U.S. Army Corps of Engineers, Omaha District, as part of the Missouri River Bank Stabilization and Navigation Mitigation Project, has constructed 17 off-channel chutes along the channelized Missouri River, downstream from Sioux City, Iowa, to increase habitat diversity. To better understand characteristics of suspended and streambed sediment within these constructed chutes, the U.S. Geological Survey investigated specific aspects of chute design and function in relation to sediment characteristics including: (1) effects of inlet structures; (2) changes occurring between the inlet and the outlet of a chute; (3) effects of chutes on sediment characteristics in the main channel; and (4) differences in chute dynamics between sampled chutes. Two chutes differing in design, location, and dynamics were studied, Upper Hamburg Bend near Nebraska City, Nebr., and Glovers Point Bend near Winnebago, Nebr. Each site was characterized using five or more sampling transects (two in the chute and three to four in the main channel) designed to bracket sediment exchanges between chutes and the main channel. A sixth transect was included at the Upper Hamburg Bend study site to account for the effects of a nontarget chute having its inlet midway between the inlet and outlet of the primary chute. Representative samples of suspended and streambed sediment were collected at each transect, along with measurements of turbidity and streamflow, between June and November 2008. Four sets of samples were collected at the Glovers Point Bend study site and five sample sets were collected from the Upper Hamburg Bend study site. Results from paired t-tests and standard t-tests indicated that the inlet structure design, passing inflow only from the top of the main-channel water column, reduced the supply of coarse-grained suspended sediment entering the chutes. Statistical comparisons did not indicate differences between the inlet and outlet of either chute; however, anecdotal evidence of recent bank erosion and in-channel deposition was observed in both chutes during the study period. Chutes had little effect on Missouri River main-channel sediment characteristics, which could be explained by the much greater streamflow of the main channel. Between-chute comparisons showed no significant differences in the suspended-sediment characteristics; however, the Upper Hamburg Bend chute had a coarser streambed, wider channel, and much greater streamflow than did the Glovers Point Bend chute.

Synthesis study of nondestructive testing devices for use in overlay thickness design of flexible pavements

NASA Astrophysics Data System (ADS)

Smith, R. E.; Lytton, R. L.

1984-04-01

A ready reference for highway engineers who are interested in purchasing nondestructive testing (NDT) equipment for use in designing overlays for flexible pavements was prepared. All commercially available equipment is described. Information includes basic descriptions plus current prices quoted by the manufacturers/distributors. To determine user comments, a questionnaire was sent to nine State agencies, and one Federal agency. The responses to these questionnaires are summarized. Overlay thickness design procedures for flexible pavements are reviewed. Important components related to the use of NDT deflection measuremnts in overlay design are identified and addressed. Summary tables of equipment characteristics and overlay design procedures are presented.

An inverter/controller subsystem optimized for photovoltaic applications

NASA Technical Reports Server (NTRS)

Pickrell, R. L.; Osullivan, G.; Merrill, W. C.

1978-01-01

Conversion of solar array dc power to ac power stimulated the specification, design, and simulation testing of an inverter/controller subsystem tailored to the photovoltaic power source characteristics. Optimization of the inverter/controller design is discussed as part of an overall photovoltaic power system designed for maximum energy extraction from the solar array. The special design requirements for the inverter/ controller include: a power system controller (PSC) to control continuously the solar array operating point at the maximum power level based on variable solar insolation and cell temperatures; and an inverter designed for high efficiency at rated load and low losses at light loadings to conserve energy.

Thermal Analysis and Design of an Advanced Space Suit

NASA Technical Reports Server (NTRS)

Lin, Chin H.; Campbell, Anthony B.; French, Jonathan D.; French, D.; Nair, Satish S.; Miles, John B.

2000-01-01

The thermal dynamics and design of an Advanced Space Suit are considered. A transient model of the Advanced Space Suit has been developed and implemented using MATLAB/Simulink to help with sizing, with design evaluation, and with the development of an automatic thermal comfort control strategy. The model is described and the thermal characteristics of the Advanced Space suit are investigated including various parametric design studies. The steady state performance envelope for the Advanced Space Suit is defined in terms of the thermal environment and human metabolic rate and the transient response of the human-suit-MPLSS system is analyzed.

Design Characteristics and Tobacco Metal Concentrations in Filtered Cigars.

PubMed

Caruso, Rosalie V; O'Connor, Richard J; Travers, Mark J; Delnevo, Cristine D; Stephens, W Edryd

2015-11-01

While U.S. cigarette consumption has declined, cigar use has steadily increased, for reasons including price compared to cigarettes and the availability of filtered varieties resembling cigarettes, and flavors that have been banned in cigarettes (excluding menthol). Little published data exists on the design characteristics of such cigars. A variety of filtered cigar brands were tested for design characteristics such as whole cigar weight, ventilation, and per-cigar tobacco weight. Cigar sticks were then sent to the University of St. Andrews for metal concentration testing of As, Pb, Cr, Ni, and Cd. Large and small cigars were statistically different between cigar weight (p ≤ .001), per-cigar tobacco weight (p = .001), rod diameter (p = .006), and filter diameter (p = .012). The differences in mean ventilation (overall mean = 19.6%, min. = 0.84%, max. = 57.6%) across filtered cigar brands were found to be statistically significant (p = .031), and can be compared to the ventilation of the average of 2013 U.S. Marlboro Red, Gold, and Silver packs at 29% ventilation. There were no significant differences for metal concentrations between cigar types (p = .650), with Pb and As levels being similar to U.S. 2009 cigarette concentrations, Cd cigar levels being slightly higher, and Cr and Ni levels much lower than cigarette levels. With cigar use rising, and filtered cigars displaying substantial similarities to filtered cigarettes, more research on product characteristics is warranted. Future plans include testing tobacco alkaloid and more observation of cigar weight for tax bracket purposes. © The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

40 CFR 267.1101 - What design and operating standards must my containment building meet?

Code of Federal Regulations, 2010 CFR

2010-07-01

...) Stresses of daily operation, including the movement of heavy equipment within the unit and contact of such... characteristics of the waste to be managed. (f) If appropriate to the nature of the waste management operation to...

40 CFR 267.1101 - What design and operating standards must my containment building meet?

Code of Federal Regulations, 2012 CFR

2012-07-01

...) Stresses of daily operation, including the movement of heavy equipment within the unit and contact of such... characteristics of the waste to be managed. (f) If appropriate to the nature of the waste management operation to...

40 CFR 267.1101 - What design and operating standards must my containment building meet?

Code of Federal Regulations, 2011 CFR

2011-07-01

...) Stresses of daily operation, including the movement of heavy equipment within the unit and contact of such... characteristics of the waste to be managed. (f) If appropriate to the nature of the waste management operation to...

40 CFR 267.1101 - What design and operating standards must my containment building meet?

Code of Federal Regulations, 2013 CFR

2013-07-01

...) Stresses of daily operation, including the movement of heavy equipment within the unit and contact of such... characteristics of the waste to be managed. (f) If appropriate to the nature of the waste management operation to...

40 CFR 267.1101 - What design and operating standards must my containment building meet?

Code of Federal Regulations, 2014 CFR

2014-07-01

...) Stresses of daily operation, including the movement of heavy equipment within the unit and contact of such... characteristics of the waste to be managed. (f) If appropriate to the nature of the waste management operation to...

Responding to Industry Demands: Advanced Technology Centers.

ERIC Educational Resources Information Center

Smith, Elizabeth Brient

1991-01-01

Discusses characteristics identified by the Center for Occupational Research and Development as indicative of fully functioning advanced technology centers, including the provision of training and retraining in such areas as design, manufacturing, materials science, and electro-optics; technology transfer; demonstration sites; needs assessment;…

Portable direct methanol fuel cell systems

NASA Technical Reports Server (NTRS)

Narayanan, S. R.; Valdez, T. I.

2002-01-01

This article includes discussion of the specific power and power density requirements for various portable system applications, the status of stack technology, progress in the implementation of balance-of-plant designs, and a summary of the characteristics of various DMFC portable power source demonstrations.

The Biomarkers of Exposure and Effect in Agriculture (BEEA) Study: Rationale, design, methods, and participant characteristics

EPA Science Inventory

Agricultural exposures including pesticides, endotoxin, and allergens have been associated with risk of various cancers and other chronic diseases, although the biological mechanisms underlying these associations are generally unclear. To facilitate future molecular epidemiologic...

Owning and Operating a Business.

ERIC Educational Resources Information Center

Ohio State Univ., Columbus. Instructional Materials Lab.

This short course is designed to offer entrepreneurship as a career option. It outlines advantages and disadvantages of entrepreneurship, characteristics of successful business owners, and resources available to assist entrepreneurs. The course outlines five 40-minute sessions, each including objectives, appropriate exercises, student worksheets,…

Self-Analysis and Assessment of Entrepreneurial Potential.

ERIC Educational Resources Information Center

King, Albert S.

1985-01-01

Presents an exercise which is designed to identify behavior characteristics and attitudes and enable individuals to identify and understand personality traits that have essential implications for becoming a successful entrepreneur. Discussion includes the personality traits of the successful entrepreneur and situational factors contributing to…

High Speed Research (HSR) Multi-Year Summary Report for Calendar Years 1995-1999

NASA Technical Reports Server (NTRS)

Baker, Myles; Boyd, William

1999-01-01

The Aeroelasticity Task is intended to provide demonstrated technology readiness to predict and improve flutter characteristics of an HSCT configuration. This requires aerodynamic codes that are applicable to the wide range of flight regimes in which the HSCT will operate, and are suitable to provide the higher fidelity required for evaluation of aeroservoelastic coupling effects. Prediction of these characteristics will result in reduced airplane weight and risk associated with a highly flexible, low-aspect ratio supersonic airplane with narrow fuselage, relatively thin wings, and heavy engines. This Task is subdivided into three subtasks. The first subtask includes the design, fabrication, and testing of wind-tunnel models suitable to provide an experimental database relevant to HSCT configurations. The second subtask includes validation of candidate unsteady aerodynamic codes, applicable in the Mach and frequency ranges of interest for the HSCT, through analysis test correlation with the test data. The third subtask includes efforts to develop and enhance these codes for application to HSCT configurations. The wind tunnel models designed and constructed during this program furnished data which were useful for the analysis test correlation work but there were shortcomings. There was initial uncertainty in the proper tunnel configuration for testing, there was a need for higher quality measured model geometry, and there was a need for better measured model displacements in the test data. One of the models exhibited changes in its dynamic characteristics during testing. Model design efforts were hampered by a need for more and earlier analysis support and better knowledge of material properties. Success of the analysis test correlation work was somewhat muted by the uncertainties in the wind tunnel model data. The planned extent of the test data was not achieved, partly due to the delays in the model design and fabrication which could not be extended due to termination of the HSR program.

The relation between sexual interest and personality characteristics in men: an eye-tracking study.

PubMed

Tsujimura, A; Miyagawa, Y; Takada, S; Nagahara, A; Matsuoka, Y; Takao, T; Nakayama, J; Matsushita, M; Nonomura, N; Okuyama, A

2010-01-01

There is a large individual deviation for men, which may be caused by a difference in personality characteristics, in sexual interest in response to sexual stimuli. In this study, we investigate whether attention to the sexual region in a video depends on the personality characteristics of men, assessing this with an eye-tracking system. The study included 30 healthy males with a normal psychological state, who viewed a sexual video in which the sexual region had been designated. Visual attention was measured across the designated region according to gaze duration. Ten types of personality characteristics were evaluated as a T-score by a questionnaire. By Pearson's correlation coefficient, the relations between gaze duration at the sexual region and T-scores of paranoia, psychasthenia and social introversion were found to be statistically significant. By multivariate stepwise regression analysis, only social introversion was negatively associated with the sexual region. Even normal variation of personality characteristics can affect the viewing period of the sexual region. This is the first report showing that subjects with a high degree of paranoia, psychasthenia and particularly social introversion have a tendency to view the sexual region for a shorter duration.

Behavioral headache research: methodologic considerations and research design alternatives.

PubMed

Hursey, Karl G; Rains, Jeanetta C; Penzien, Donald B; Nash, Justin M; Nicholson, Robert A

2005-05-01

Behavioral headache treatments have garnered solid empirical support in recent years, but there is substantial opportunity to strengthen the next generation of studies with improved methods and consistency across studies. Recently, Guidelines for Trials of Behavioral Treatments for Recurrent Headache were published to facilitate the production of high-quality research. The present article compliments the guidelines with a discussion of methodologic and research design considerations. Since there is no research design that is applicable in every situation, selecting an appropriate research design is fundamental to producing meaningful results. Investigators in behavioral headache and other areas of research consider the developmental phase of the research, the principle objectives of the project, and the sources of error or alternative interpretations in selecting a design. Phases of clinical trials typically include pilot studies, efficacy studies, and effectiveness studies. These trials may be categorized as primarily pragmatic or explanatory. The most appropriate research designs for these different phases and different objectives vary on such characteristics as sample size and assignment to condition, types of control conditions, periods or frequency of measurement, and the dimensions along which comparisons are made. A research design also must fit within constraints on available resources. There are a large number of potential research designs that can be used and considering these characteristics allows selection of appropriate research designs.

LH2 fuel tank design for SSTO

NASA Technical Reports Server (NTRS)

Wright, Geoff

1994-01-01

This report will discuss the design of a liquid hydrogen fuel tank constructed from composite materials. The focus of this report is to recommend a design for a fuel tank which will be able to withstand all static and dynamic forces during manned flight. Areas of study for the design include material selection, material structural analysis, heat transfer, thermal expansion, and liquid hydrogen diffusion. A structural analysis FORTRAN program was developed for analyzing the buckling and yield characteristics of the tank. A thermal analysis Excel spreadsheet was created to determine a specific material thickness which will minimize heat transfer through the wall of the tank. The total mass of the tank was determined by the combination of both structural and thermal analyses. The report concludes with the recommendation of a layered material tank construction. The designed system will include exterior insulation, combination of metal and organize composite matrices and honeycomb.

External validity of randomized controlled trials in older adults, a systematic review.

PubMed

van Deudekom, Floor J; Postmus, Iris; van der Ham, Danielle J; Pothof, Alexander B; Broekhuizen, Karen; Blauw, Gerard J; Mooijaart, Simon P

2017-01-01

To critically assess the external validity of randomized controlled trials (RCTs) it is important to know what older adults have been enrolled in the trials. The aim of this systematic review is to study what proportion of trials specifically designed for older patients report on somatic status, physical and mental functioning, social environment and frailty in the patient characteristics. PubMed was searched for articles published in 2012 and only RCTs were included. Articles were further excluded if not conducted with humans or only secondary analyses were reported. A random sample of 10% was drawn. The current review analyzed this random sample and further selected trials when the reported mean age was ≥ 60 years. We extracted geriatric assessments from the population descriptives or the in- and exclusion criteria. In total 1396 trials were analyzed and 300 trials included. The median of the reported mean age was 66 (IQR 63-70) and the median percentage of men in the trials was 60 (IQR 45-72). In 34% of the RCTs specifically designed for older patients somatic status, physical and mental functioning, social environment or frailty were reported in the population descriptives or the in- and exclusion criteria. Physical and mental functioning was reported most frequently (22% and 14%). When selecting RCTs on a mean age of 70 or 80 years the report of geriatric assessments in the patient characteristics was 46% and 85% respectively but represent only 5% and 1% of the trials. Somatic status, physical and mental functioning, social environment and frailty are underreported even in RCTs specifically designed for older patients published in 2012. Therefore, it is unclear for clinicians to which older patients the results can be applied. We recommend systematic to transparently report these relevant characteristics of older participants included in RCTs.

Trenched raised cosine FMF for differential mode delay management in next generation optical networks

NASA Astrophysics Data System (ADS)

Chebaane, Saleh; Fathallah, Habib; Seleem, Hussein; Machhout, Mohsen

2018-02-01

Dispersion management in few mode fiber (FMF) technology is crucial to support the upcoming standard that reaches 400 Gbps and Terabit/s per wavelength. Recently in Chebaane et al. (2016), we defined two potential differential mode delay (DMD) management strategies, namely sawtooth and triangular. Moreover we proposed a novel parametric refractive index profile for FMF, referred as raised cosine (RC) profile. In this article, we improve and optimize the RC profile design by including additional shaping parameters, in order to obtain much more attractive dispersion characteristics. Our improved design enabled to obtain a zero DMD (z-DMD), strong positive DMD (p-DMD) and near-zero DMD (nz-DMD) for six-mode fiber, all appropriate for dispersion management in FMF system. In addition, we propose a positive DMD (p-DMD) fiber designs for both, four-mode fiber (4-FMF) and six-mode fiber (6-FMF), respectively, having particularly attractive dispersion characteristics.

A comparative study of restricted randomization procedures for multiarm trials with equal or unequal treatment allocation ratios.

PubMed

Ryeznik, Yevgen; Sverdlov, Oleksandr

2018-06-04

Randomization designs for multiarm clinical trials are increasingly used in practice, especially in phase II dose-ranging studies. Many new methods have been proposed in the literature; however, there is lack of systematic, head-to-head comparison of the competing designs. In this paper, we systematically investigate statistical properties of various restricted randomization procedures for multiarm trials with fixed and possibly unequal allocation ratios. The design operating characteristics include measures of allocation balance, randomness of treatment assignments, variations in the allocation ratio, and statistical characteristics such as type I error rate and power. The results from the current paper should help clinical investigators select an appropriate randomization procedure for their clinical trial. We also provide a web-based R shiny application that can be used to reproduce all results in this paper and run simulations under additional user-defined experimental scenarios. Copyright © 2018 John Wiley & Sons, Ltd.

Results of design studies and wind tunnel tests of high-aspect-ratio supercritical wings for an energy efficient transport

NASA Technical Reports Server (NTRS)

Steckel, D. K.; Dahlin, J. A.; Henne, P. A.

1980-01-01

These basic characteristics of critical wings included wing area, aspect ratio, average thickness, and sweep as well as practical constraints on the planform and thickness near the wing root to allow for the landing gear. Within these constraints, a large matrix of wing designs was studied with spanwise variations in the types of airfoils and distribution of lift as well as some small planform changes. The criteria by which the five candidate wings were chosen for testing were the cruise and buffet characteristics in the transonic regime and the compatibility of the design with low speed (high-lift) requirements. Five wing-wide-body configurations were tested in the NASA Ames 11-foot transonic wind tunnel. Nacelles and pylons, flap support fairings, tail surfaces, and an outboard aileron were also tested on selected configurations.

High-angle-of-attack aerodynamics - Lessons learned

NASA Technical Reports Server (NTRS)

Chambers, J. R.

1986-01-01

Recently, the military and civil technical communities have undertaken numerous studies of the high angle-of-attack aerodynamic characteristics of advanced airplane and missile configurations. The method of approach and the design methodology employed have necessarily been experimental and exploratory in nature, due to the complex nature of separated flows. However, despite the relatively poor definition of many of the key aerodynamic phenomena involved for high-alpha conditions, some generic guidelines for design consideration have been identified. The present paper summarizes some of the more important lessons learned in the area of high angle-of-attack aerodynamics with examples of a number of key concepts and with particular emphasis on high-alpha stability and control characteristics of high performance aircraft. Topics covered in the discussion include the impact of design evolution, forebody flows, control of separated flows, configuration effects, aerodynamic controls, wind-tunnel flight correlation, and recent NASA research activities.

The design of two sonic boom wind tunnel models from conceptual aircraft which cruise at Mach numbers of 2.0 and 3.0

NASA Technical Reports Server (NTRS)

Mack, Robert J.; Needleman, Kathy E.

1990-01-01

A method for designing wind tunnel models of conceptual, low-boom, supersonic cruise aircraft is presented. Also included is a review of the procedures used to design the conceptual low-boom aircraft. In the discussion, problems unique to, and encountered during, the design of both the conceptual aircraft and the wind tunnel models are outlined. The sensitivity of low-boom characteristics in the aircraft design to control the volume and lift equivalent area distributions was emphasized. Solutions to these problems are reported; especially the two which led to the design of the wind tunnel model support stings.

Predicting the effects of unmodeled dynamics on an aircraft flight control system design using eigenspace assignment

NASA Technical Reports Server (NTRS)

Johnson, Eric N.; Davidson, John B.; Murphy, Patrick C.

1994-01-01

When using eigenspace assignment to design an aircraft flight control system, one must first develop a model of the plant. Certain questions arise when creating this model as to which dynamics of the plant need to be included in the model and which dynamics can be left out or approximated. The answers to these questions are important because a poor choice can lead to closed-loop dynamics that are unpredicted by the design model. To alleviate this problem, a method has been developed for predicting the effect of not including certain dynamics in the design model on the final closed-loop eigenspace. This development provides insight as to which characteristics of unmodeled dynamics will ultimately affect the closed-loop rigid-body dynamics. What results from this insight is a guide for eigenstructure control law designers to aid them in determining which dynamics need or do not need to be included and a new way to include these dynamics in the flight control system design model to achieve a required accuracy in the closed-loop rigid-body dynamics. The method is illustrated for a lateral-directional flight control system design using eigenspace assignment for the NASA High Alpha Research Vehicle (HARV).

Neighborhood socioeconomic deprivation characteristics in child (0-18 years) health studies: a review.

PubMed

van Vuuren, C Leontine; Reijneveld, Sijmen A; van der Wal, Marcel F; Verhoeff, Arnoud P

2014-09-01

Growing up in socioeconomically deprived neighborhoods has been shown to have negative health effects on children. However, the most recent review on which measures are used to investigate the association between neighborhood characteristics and child (0-18 year) health included studies only until 2004. Insight into more recent research is needed for the further development of these measures. To review neighborhood socioeconomic deprivation characteristics used in recent studies investigating the relationship between neighborhood socioeconomic deprivation and child health. Sensitive search in MEDLINE, Embase, PsycINFO, Sociological Abstracts databases (2004-2013). Ultimately, 19 studies were included. We found ten neighborhood socioeconomic deprivation constructs, of which income/wealth, employment, and education were most frequently used. The choice for neighborhood characteristics seemed independent of the health outcome and in most cases was not based on a specific theoretical background or earlier work. Studies vary regarding study designs, measures and outcomes. Researchers should clearly specify their choice of neighborhood socioeconomic deprivation characteristics; preferably, these should be theory-based and used consistently. Copyright © 2014 Elsevier Ltd. All rights reserved.

Factors influencing confidential unit exclusions in blood donors.

PubMed

Sümnig, A; Konerding, U; Kohlmann, T; Greinacher, A

2010-04-01

In many countries blood donors can exclude their donated blood from being transfused in a confidential unit exclusion (CUE) process. We aimed to identify characteristics which might influence the decision for CUE. In a 3-step approach we first enrolled 29 German blood donation centers in 2005 and addressed how the clarity of different CUE forms applied in these centers was rated by first time blood donors and also assessed three newly designed CUE forms. Second, we performed a survey on the characteristics of the CUE process including 25 centers. Third, we performed an intervention study, in which the CUE form originally applied in the study centre was compared with a newly developed CUE form in a before-after study design with respect to the corresponding CUE rates. (1) Clarity of the CUE forms varied considerably. (2) The CUE rate was higher (P < 0.05) when nurses rather than a physician were involved in informing the donors and when the CUE form was submitted anonymously instead of being handed to a person. (3) Application of the newly designed CUE form which was rated as being very clear resulted in a 31% decrease in the CUE rate. Design of the CUE form and characteristics of the CUE process may considerably influence the CUE rates.

Development and verification of an innovative photomultiplier calibration system with a 10-fold increase in photometer resolution

NASA Astrophysics Data System (ADS)

Jiang, Shyh-Biau; Yeh, Tse-Liang; Chen, Li-Wu; Liu, Jann-Yenq; Yu, Ming-Hsuan; Huang, Yu-Qin; Chiang, Chen-Kiang; Chou, Chung-Jen

2018-05-01

In this study, we construct a photomultiplier calibration system. This calibration system can help scientists measuring and establishing the characteristic curve of the photon count versus light intensity. The system uses an innovative 10-fold optical attenuator to enable an optical power meter to calibrate photomultiplier tubes which have the resolution being much greater than that of the optical power meter. A simulation is firstly conducted to validate the feasibility of the system, and then the system construction, including optical design, circuit design, and software algorithm, is realized. The simulation generally agrees with measurement data of the constructed system, which are further used to establish the characteristic curve of the photon count versus light intensity.

Design and manufacture of wheels for a dual-mode (manned - automatic) lunar surface roving vehicle. Volume 2: Proposed test plan

NASA Technical Reports Server (NTRS)

1970-01-01

A developmental test plan for the wheel and wheel drive assembly of the dual-mode (manned/automated) lunar surface roving vehicle is presented. The tests cover performance, as well as critical environmental characteristics. Insofar as practical, the environmental conditions imposed will be in the sequence expected during the hardware's life from storage through the lunar mission. Test procedures are described for static load deflection and endurance tests. Soft soil tests to determine mobility characteristics including drawbar-pull and thrust vs slip, and motion resistance for various wheel loads are also discussed. Test designs for both ambient and thermal vacuum conditions are described. Facility, transducer, and instrumentation requirements are outlined.

Cochlear implant-related three-dimensional characteristics determined by micro-computed tomography reconstruction.

PubMed

Ni, Yusu; Dai, Peidong; Dai, Chunfu; Li, Huawei

2017-01-01

To explore the structural characteristics of the cochlea in three-dimensional (3D) detail using 3D micro-computed tomography (mCT) image reconstruction of the osseous labyrinth, with the aim of improving the structural design of electrodes, the selection of stimulation sites, and the effectiveness of cochlear implantation. Three temporal bones were selected from among adult donors' temporal bone specimens. A micro-CT apparatus (GE eXplore) was used to scan three specimens with a voxel resolution of 45 μm. We obtained about 460 slices/specimen, which produced abundant data. The osseous labyrinth images of three specimens were reconstructed from mCT. The cochlea and its spiral characteristics were measured precisely using Able Software 3D-DOCTOR. The 3D images of the osseous labyrinth, including the cochlea, vestibule, and semicircular canals, were reconstructed. The 3D models of the cochlea showed the spatial relationships and surface structural characteristics. Quantitative data concerning the cochlea and its spiral structural characteristics were analyzed with regard to cochlear implantation. The 3D reconstruction of mCT images clearly displayed the detailed spiral structural characteristics of the osseous labyrinth. Quantitative data regarding the cochlea and its spiral structural characteristics could help to improve electrode structural design, signal processing, and the effectiveness of cochlear implantation. Clin. Anat. 30:39-43, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Aerodynamic Characteristics of Two Waverider-Derived Hypersonic Cruise Configurations

NASA Technical Reports Server (NTRS)

Cockrell, Charles E., Jr.; Huebner, Lawrence D.; Finley, Dennis B.

1996-01-01

An evaluation was made on the effects of integrating the required aircraft components with hypersonic high-lift configurations known as waveriders to create hypersonic cruise vehicles. Previous studies suggest that waveriders offer advantages in aerodynamic performance and propulsion/airframe integration (PAI) characteristics over conventional non-waverider hypersonic shapes. A wind-tunnel model was developed that integrates vehicle components, including canopies, engine components, and control surfaces, with two pure waverider shapes, both conical-flow-derived waveriders for a design Mach number of 4.0. Experimental data and limited computational fluid dynamics (CFD) solutions were obtained over a Mach number range of 1.6 to 4.63. The experimental data show the component build-up effects and the aerodynamic characteristics of the fully integrated configurations, including control surface effectiveness. The aerodynamic performance of the fully integrated configurations is not comparable to that of the pure waverider shapes, but is comparable to previously tested hypersonic models. Both configurations exhibit good lateral-directional stability characteristics.

Performance Demonstration of Mcmb-LiNiCoO2 Cells Containing Electrolytes Designed for Wide Operating Temperature Range

NASA Technical Reports Server (NTRS)

Smart, M. C.; Ratnakumar, B. V.; Whicanack, L. D.; Smith, K. A.; Santee, S.; Puglia, F. J.; Gitzendanner, R.

2009-01-01

With the intent of improving the performance of Li-ion cells over a wide operating temperature range, we have investigated the use of co-solvents to improve the properties of electrolyte formulations. In the current study, we have focused upon evaluating promising electrolytes which have been incorporated into large capacity (7 Ah) prototype Li-ion cells, fabricated by Yardney Technical Products, Inc. The electrolytes selected for performance evaluation include the use of a number of esters as co-solvents, including methyl propionate (MP), ethyl propionate (EP), ethyl butyrate (EB), propyl butyrate (PB), and 2,2,2-trifluoroethyl butyrate (TFEB). The performance of the prototype cells containing the ester-based electrolytes was compared with an extensive data base generated on cells containing previously developed all carbonate-based electrolytes. A number of performance tests were performed, including determining (i) the discharge rate capacity over a wide range of temperatures, (ii) the charge characteristics, (iii) the cycle life characteristics under various conditions, and (iv) the impedance characteristics.

Tactical radar technology study. Volume 1: Executive summary

NASA Astrophysics Data System (ADS)

Rosien, R.; Cardone, L.; Hammers, D.; Klein, A.; Nozawa, E.

1980-03-01

This report presents results of a study to identify new technology required to provide advanced multi-threat performance capabilities in future tactical surveillance radar designs. A baseline design with optional subsystem characteristics has been synthesized to provide both functional and operational survivability in a dynamic and hostile situation postulated for the post 1985 time frame. Comparisons have been made of available technology with that required by the new baseline design to identify new technology requirements. Recommendations are presented for critical new technology programs including estimates of technical risks, costs and required development time.

Management Of Optical Projects

NASA Astrophysics Data System (ADS)

Young, Peter S.; Olson, David R.

1981-03-01

This paper discusses the management of optical projects from the concept stage, beginning with system specifications, through design, optical fabrication and test tasks. Special emphasis is placed on effective coupling of design engineering with fabrication development and utilization of available technology. Contrasts are drawn between accepted formalized management techniques, the realities of dealing with fragile components and the necessity of an effective project team which integrates the special characteristics of highly skilled optical specialists including lens designers, optical engineers, opticians, and metrologists. Examples are drawn from the HEAO-2 X-Ray Telescope and Space Telescope projects.

Exploring Mechanisms for Effective Technology-Enhanced Simulation-based Education in Wilderness Medicine: A Systematic Review.

PubMed

MacKinnon, Ralph; Aitken, Deborah; Humphries, Christopher

2015-12-17

 Technology-enhanced simulation is well-established in healthcare teaching curricula, including those regarding wilderness medicine. Compellingly, the evidence base for the value of this educational modality to improve learner competencies and patient outcomes are increasing.  The aim was to systematically review the characteristics of technology-enhanced simulation presented in the wilderness medicine literature to date. Then, the secondary aim was to explore how this technology has been used and if the use of this technology has been associated with improved learner or patient outcomes.  EMBASE and MEDLINE were systematically searched from 1946 to 2014, for articles on the provision of technology-enhanced simulation to teach wilderness medicine. Working independently, the team evaluated the information on the criteria of learners, setting, instructional design, content, and outcomes.  From a pool of 37 articles, 11 publications were eligible for systematic review. The majority of learners in the included publications were medical students, settings included both indoors and outdoors, and the main focus clinical content was initial trauma management with some including leadership skills. The most prevalent instructional design components were clinical variation and cognitive interactivity, with learner satisfaction as the main outcome.  The results confirm that the current provision of wilderness medicine utilizing technology-enhanced simulation is aligned with instructional design characteristics that have been used to achieve effective learning. Future research should aim to demonstrate the translation of learning into the clinical field to produce improved learner outcomes and create improved patient outcomes.

21 CFR 861.7 - Contents of standards.

Code of Federal Regulations, 2011 CFR

2011-04-01

... DEVICES PROCEDURES FOR PERFORMANCE STANDARDS DEVELOPMENT General § 861.7 Contents of standards. Any performance standard established under this part will include such provisions as the Food and Drug... address (but need not be limited to): (a) Performance characteristics of the device; (b) The design...

Developing a Distributed Computing Architecture at Arizona State University.

ERIC Educational Resources Information Center

Armann, Neil; And Others

1994-01-01

Development of Arizona State University's computing architecture, designed to ensure that all new distributed computing pieces will work together, is described. Aspects discussed include the business rationale, the general architectural approach, characteristics and objectives of the architecture, specific services, and impact on the university…

Orbit Transfer Vehicle (OTV) advanced expander cycle engine point design study. Volume 3: Engine data summary

NASA Technical Reports Server (NTRS)

1981-01-01

The engine operating characteristics were examined. Inlet pressure effects, tank pressurization effects, steady-state specific impulse, and the steady-state cycle were studied. The propellant flow schematic and operating sequence are presented. Engine hardware drawings are included.

Meet the Herps.

ERIC Educational Resources Information Center

Naturescope, 1987

1987-01-01

Describes some of the characteristics of "herps" (amphibians and reptiles). Contains teaching activities dealing with ancient herps, learning stations that encourage sensory experiences with herps, and games, puzzles, and a dramatic play about herps. Includes reproducible handouts designed to be used with the activities, as well as a quiz. (TW)

Ceramic technology for automotive turbines

NASA Technical Reports Server (NTRS)

Mclean, A. F.

1982-01-01

The paper presents an update on ceramic technology for automotive turbines. Progress in research and development of improved ceramics is reviewed, including approaches for assessing time-dependent strength characteristics. Processes for making shapes are discussed, and the design and testing of selected ceramic turbine components are reviewed.

Instructional Design and Directed Cognitive Processing.

ERIC Educational Resources Information Center

Bovy, Ruth Colvin

This paper argues that the information processing model provides a promising basis on which to build a comprehensive theory of instruction. Characteristics of the major information processing constructs are outlined including attention, encoding and rehearsal, working memory, long term memory, retrieval, and metacognitive processes, and a unifying…

Large space telescope, phase A. Volume 4: Scientific instrument package

NASA Technical Reports Server (NTRS)

1972-01-01

The design and characteristics of the scientific instrument package for the Large Space Telescope are discussed. The subjects include: (1) general scientific objectives, (2) package system analysis, (3) scientific instrumentation, (4) imaging photoelectric sensors, (5) environmental considerations, and (6) reliability and maintainability.

40 CFR 63.495 - Back-end process provisions-procedures to determine compliance with residual organic HAP...

Code of Federal Regulations, 2011 CFR

2011-07-01

... current process operating conditions. (iii) Design analysis based on accepted chemical engineering... quantity are production records, measurement of stream characteristics, and engineering calculations. (5...-end process operations using engineering assessment. Engineering assessment includes, but is not...

40 CFR 63.495 - Back-end process provisions-procedures to determine compliance with residual organic HAP...

Code of Federal Regulations, 2013 CFR

2013-07-01

... current process operating conditions. (iii) Design analysis based on accepted chemical engineering... quantity are production records, measurement of stream characteristics, and engineering calculations. (5...-end process operations using engineering assessment. Engineering assessment includes, but is not...

40 CFR 63.495 - Back-end process provisions-procedures to determine compliance with residual organic HAP...

Code of Federal Regulations, 2014 CFR

2014-07-01

... current process operating conditions. (iii) Design analysis based on accepted chemical engineering... quantity are production records, measurement of stream characteristics, and engineering calculations. (5...-end process operations using engineering assessment. Engineering assessment includes, but is not...

40 CFR 63.495 - Back-end process provisions-procedures to determine compliance with residual organic HAP...

Code of Federal Regulations, 2012 CFR

2012-07-01

... current process operating conditions. (iii) Design analysis based on accepted chemical engineering... quantity are production records, measurement of stream characteristics, and engineering calculations. (5...-end process operations using engineering assessment. Engineering assessment includes, but is not...

Connections: Ocean Environments. Unit Grade 5.

ERIC Educational Resources Information Center

Ney, Catherine R.

Ocean Environments for Grade 5 is a 12-week interdisciplinary ocean environmental unit designed for teachers to use with their students. The unit emphasizes investigation and understanding of our ocean environments, including their geological, physical, and biological characteristics. It also stresses awareness of public policy decisions related…

SHARING EDUCATIONAL SERVICES.

ERIC Educational Resources Information Center

Catskill Area Project in Small School Design, Oneonta, NY.

SHARED SERVICES, A COOPERATIVE SCHOOL RESOURCE PROGRAM, IS DEFINED IN DETAIL. INCLUDED IS A DISCUSSION OF THEIR NEED, ADVANTAGES, GROWTH, DESIGN, AND OPERATION. SPECIFIC PROCEDURES FOR OBTAINING STATE AID IN SHARED SERVICES, EFFECTS OF SHARED SERVICES ON THE SCHOOL, AND HINTS CONCERNING SHARED SERVICES ARE DESCRIBED. CHARACTERISTICS OF THE SMALL…

Teaching Followership in Leadership Education

ERIC Educational Resources Information Center

Raffo, Deana M.

2013-01-01

This paper provides leadership educators with a resource for teaching followership. It presents a lesson for teaching students about followership in contemporary society by including key concepts and follower characteristics followed by class activities and assignments designed to engage students in active learning and self-reflective processes. A…

X-Gliders: Exploring Flight Research with Experimental Gliders. Educational Brief.

ERIC Educational Resources Information Center

National Aeronautics and Space Administration, Washington, DC.

This brief discusses X-gliders and flight research with experimental gliders. In this activity, designed for grades K-4, students will learn how to change the flight characteristics of a glider using scientific inquiry methods. Glider plans and a template are included. (MVL)

Newman Unit 1 advanced solar repowering. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1982-04-01

The five appendices give the selection process and system specification of the Newman Unit 1 solar repowering system, including the conceptual design drawings and diagrams; input data for the simulation program; and a review of the most important characteristics of the existing plant. (LEW)

Methods and Materials for Teaching the Gifted.

ERIC Educational Resources Information Center

Karnes, Frances A., Ed.; Bean, Suzanne M., Ed.

This book is designed to provide strategies and resources for differentiating the instruction of gifted learners. It addresses characteristics and needs of gifted learners, instructional planning and evaluation, strategies for best practices, and supporting and enhancing gifted programs. Specific chapters include: (1) "Gifted and Talented…

Experiments on identification and control of inflow disturbances in contracting streams

NASA Technical Reports Server (NTRS)

Lee, A. H.; Nagib, H. M.; Tan-Atichat, J.; Wittwer, D. M.

1982-01-01

Vorticity from all surfaces and isolated objects in the vicinity of the fan intake, including the outside surfaces of the fan housing, were identified as the major sources for disturbances leading to blade passing frequency noise. The previously proposed mechanism based on atmospheric turbulence is refuted. Flow visualization and hot wire techniques were used in three different facilities to document the evolution of various types of disturbances, including the details of the mean flow and turbulence characteristics. The results suggest that special attention must be devoted to the design of the inlet and that geometric modeling may not lead to adequate simulation of the in flight characteristics. While honeycomb type flow manipulators appear to be effective in reducing some of the disturbances, higher pressure drop devices that generate adequate turbulence, for mixing of isolated nonuniformities, may be necessary to suppress the remaining disturbances. The results are also applicable to the design of inlets of open return wind tunnels and similar flow facilities.

Infant Movement Motivation Questionnaire: development of a measure evaluating infant characteristics relating to motor development in the first year of life.

PubMed

Doralp, Samantha; Bartlett, Doreen

2014-08-01

This paper highlights the development and testing of the Infant Movement Motivation Questionnaire (IMMQ), an instrument designed to evaluate qualities of infant characteristics that relate specifically to early motor development. The measurement development process included three phases: item generation, pilot testing and evaluation of acceptability and feasibility for parents and exploratory factor analysis. The resultant 27-item questionnaire is designed for completion by parents and contains four factors including Activity, Exploration, Motivation and Adaptability. Overall, the internal consistency of the IMMQ is 0.89 (Cronbach's alpha), with test-retest reliability measured at 0.92 (ICC, with 95% CI 0.83-0.96). Further work could be done to strengthen the individual factors; however it is adequate for use in its full form. The IMMQ can be used for clinical or research purposes, as well as an educational tool for parents. Copyright © 2014 Elsevier Inc. All rights reserved.

X-15: Extending the Frontiers of Flight

NASA Technical Reports Server (NTRS)

Jenkins, Dennis R.

2007-01-01

A history of the design and achievements of the high-speed, 1950s-era X-15 airplane is presented. The following chapters are included: A New Science; A Hypersonic Research Airplane; Conflict and Innovation; The Million-Horsepower Engine; High Range and Dry Lakes; Preparations; The Flight Program; and the Research Program. Selected biographies, flight logs and physical characteristics of the X-15 Airplane are included in the appendices.

Environmental impact of geopressure - geothermal cogeneration facility on wetland resources and socioeconomic characteristics in Louisiana Gulf Coast region. Final report, October 10, 1983-September 31, 1984

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smalley, A.M.; Saleh, F.M.S.; Fontenot, M.

1984-08-01

Baseline data relevant to air quality are presented. The following are also included: geology and resource assessment, design well prospects in southwestern Louisiana, water quality monitoring, chemical analysis subsidence, microseismicity, geopressure-geothermal subsidence modeling, models of compaction and subsidence, sampling handling and preparation, brine chemistry, wetland resources, socioeconomic characteristics, impacts on wetlands, salinity, toxic metals, non-metal toxicants, temperature, subsidence, and socioeconomic impacts. (MHR)

Integrated technology rotor/flight research rotor hub concept definition

NASA Technical Reports Server (NTRS)

Dixon, P. G. C.

1983-01-01

Two variations of the helicopter bearingless main rotor hub concept are proposed as bases for further development in the preliminary design phase of the Integrated Technology Rotor/Flight Research Rotor (ITR/FRR) program. This selection was the result of an evaluation of three bearingless hub concepts and two articulated hub concepts with elastomeric bearings. The characteristics of each concept were evaluated by means of simplified methodology. These characteristics included the assessment of stability, vulnerability, weight, drag, cost, stiffness, fatigue life, maintainability, and reliability.

Characteristics of difficult-to-place youth in state custody: a profile of the Exceptional Care Pilot Project population.

PubMed

Armour, Marilyn P; Schwab, James

2007-01-01

This study examines the characteristics of Texas youth designated as 'most difficult to place' recipients of service under the "Exceptional Care Pilot Project" (N = 46). Findings include, among others, high levels of comorbid psychiatric disturbance (> 3 diagnostic groupings), physical (78.3%) and sexual (88%) maltreatment, and placement breakdowns (m = 4.8 therapeutic placements). This initial profile of the population provides a base for helping other states identify and plan for the needs of their most troubled youth.

Coupled parametric design of flow control and duct shape

NASA Technical Reports Server (NTRS)

Florea, Razvan (Inventor); Bertuccioli, Luca (Inventor)

2009-01-01

A method for designing gas turbine engine components using a coupled parametric analysis of part geometry and flow control is disclosed. Included are the steps of parametrically defining the geometry of the duct wall shape, parametrically defining one or more flow control actuators in the duct wall, measuring a plurality of performance parameters or metrics (e.g., flow characteristics) of the duct and comparing the results of the measurement with desired or target parameters, and selecting the optimal duct geometry and flow control for at least a portion of the duct, the selection process including evaluating the plurality of performance metrics in a pareto analysis. The use of this method in the design of inter-turbine transition ducts, serpentine ducts, inlets, diffusers, and similar components provides a design which reduces pressure losses and flow profile distortions.

Quantum-splitting oxide-based phosphors, method of producing, and rules for designing the same

DOEpatents

Setlur, Anant Achyut; Comanzo, Holly Ann; Srivastava, Alok Mani

2003-09-16

Strontium and strontium calcium aluminates and lanthanum and lanthanum magnesium borates activated with Pr.sup.3+ and Mn.sup.2+ exhibit characteristics of quantum-splitting phosphors. Improved quantum efficiency may be obtained by further doping with Gd.sup.3+. Refined rules for designing quantum-splitting phosphors include the requirement of incorporation of Gd.sup.3+ and Mn.sup.2+ in the host lattice for facilitation of energy migration.

Aeroacoustics of Flight Vehicles: Theory and Practice. Volume 2: Noise Control

NASA Technical Reports Server (NTRS)

Hubbard, Harvey H. (Editor)

1991-01-01

Flight vehicles and the underlying concepts of noise generation, noise propagation, noise prediction, and noise control are studied. This volume includes those chapters that relate to flight vehicle noise control and operations: human response to aircraft noise; atmospheric propagation; theoretical models for duct acoustic propagation and radiation; design and performance of duct acoustic treatment; jet noise suppression; interior noise; flyover noise measurement and prediction; and quiet aircraft design and operational characteristics.

Optical Theory Improvements to Space Domain Awareness

DTIC Science & Technology

2016-09-15

to other portions of system design. These design components include the Field of View (FoV) of the telescope and the physical dimensions of the system...trying to capture physical characteristics of the object being imaged, and the blurring caused by the atmosphere degrades and limits this capability...experimentally verified in multiple physical experiments [53, 54]. The drawback to these methods is that they assume that the noise caused by the atmosphere is

Study of fuel systems for LH2-fueled subsonic transport aircraft, volume 1

NASA Technical Reports Server (NTRS)

Brewer, G. D.; Morris, R. E.; Davis, G. W.; Versaw, E. F.; Cunnington, G. R., Jr.; Riple, J. C.; Baerst, C. F.; Garmong, G.

1978-01-01

Several engine concepts examined to determine a preferred design which most effectively exploits the characteristics of hydrogen fuel in aircraft tanks received major emphasis. Many candidate designs of tank structure and cryogenic insulation systems were evaluated. Designs of all major elements of the aircraft fuel system including pumps, lines, valves, regulators, and heat exchangers received attention. Selected designs of boost pumps to be mounted in the LH2 tanks, and of a high pressure pump to be mounted on the engine were defined. A final design of LH2-fueled transport aircraft was established which incorporates a preferred design of fuel system. That aircraft was then compared with a conventionally fueled counterpart designed to equivalent technology standards.

Integrating Flight Dynamics & Control Analysis and Simulation in Rotorcraft Conceptual Design

NASA Technical Reports Server (NTRS)

Lawrence, Ben; Berger, Tom; Tischler, Mark B.; Theodore, Colin R; Elmore, Josh; Gallaher, Andrew; Tobias, Eric L.

2016-01-01

The development of a toolset, SIMPLI-FLYD ('SIMPLIfied FLight dynamics for conceptual Design') is described. SIMPLI-FLYD is a collection of tools that perform flight dynamics and control modeling and analysis of rotorcraft conceptual designs including a capability to evaluate the designs in an X-Plane-based real-time simulation. The establishment of this framework is now facilitating the exploration of this new capability, in terms of modeling fidelity and data requirements, and the investigation of which stability and control and handling qualities requirements are appropriate for conceptual design. Illustrative design variation studies for single main rotor and tiltrotor vehicle configurations show sensitivity of the stability and control characteristics and an approach to highlight potential weight savings by identifying over-design.

CPW fed UWB antenna with enhanced bandwidth & dual band notch characteristics

NASA Astrophysics Data System (ADS)

Jangid, K. G.; Jain, P. K.; Sharma, B. R.; Saxena, V. K.; Kulhar, V. S.; Bhatnagar, D.

2018-05-01

This paper reports the design and performance of CPW fed UWB antenna having two U-shaped slots etched in the radiating structure. UWB performance of proposed structure is obtained through the truncated shape of the patch and L-slits etched in ground plane. By applying two U- shaped slots in a radiating patch, we achieved dual notch band characteristics. The proposed antenna is simulated by applying CST Microwave Studio simulator. This antenna provides wide impedance bandwidth of 12.585 GHz (2.74GHz - 15.325 GHz) with dual notched band characteristics. This antenna may be proved as a useful structure for modern wireless communication systems including UWB band.

Development of a land-cover characteristics database for the conterminous U.S.

USGS Publications Warehouse

Loveland, Thomas R.; Merchant, J.W.; Ohlen, D.O.; Brown, Jesslyn F.

1991-01-01

Information regarding the characteristics and spatial distribution of the Earth's land cover is critical to global environmental research. A prototype land-cover database for the conterminous United States designed for use in a variety of global modelling, monitoring, mapping, and analytical endeavors has been created. The resultant database contains multiple layers, including the source AVHRR data, the ancillary data layers, the land-cover regions defined by the research, and translation tables linking the regions to other land classification schema (for example, UNESCO, USGS Anderson System). The land-cover characteristics database can be analyzed, transformed, or aggregated by users to meet a broad spectrum of requirements. -from Authors

Alternate Propulsion Subsystem Concepts Tripropellant Comparison Study

NASA Technical Reports Server (NTRS)

Levack, Daniel

1995-01-01

A study was conducted under MSFC contract NAS8-39210 to compare tripropellant and bipropellant engine configurations for the SSTO mission. The objective was to produce an 'apples-to-apples' comparison to isolate the effects of design implementation, designing company, year of design, or technologies included from the basic tripropellant/bipropellant comparison. Consequently, identical technologies were included (e.g., jet pumps) and the same design groundrules and practices were used. Engine power cycles were examined as were turbomachinery/preburner arrangements for each cycle. The bipropellant approach and two tripropellant approaches were separately optimized in terms of operating parameters: exit pressures, mixture ratios, thrust splits, etc. This briefing presents the results of the study including engine weights for both tripropellant and bipropellant engines; dry vehicle weight performance for a range of engine chamber pressures; discusses the basis for the results; examines vehicle performance due to engine cycles and the margin characteristics of various cycles; and identifies technologies with significant payoffs for this application.

What parental characteristics can predict child maltreatment at the Emergency Department? Considering expansion of the Hague Protocol.

PubMed

Diderich, Hester M; Dechesne, Mark; Fekkes, Minne; Verkerk, Paul H; Buitendijk, Simone E; Oudesluys-Murphy, Anne-Marie

2015-08-01

The Hague Protocol considers three parental characteristics of Emergency Department adult patients to identify child abuse: (a) domestic violence, (b) intoxication, and (c) suicide attempt or auto mutilation. This study investigated whether additional parental characteristics could be included to improve the chance of detection. Using a nested case-control design, we compared parents identified as child abusers who were missed by the Protocol with a matched group of nonabusing parents. The parental characteristics used were, among others, all physical injuries possibly resulting from domestic violence, psychological, or mental complaints that might indicate elevated domestic stress levels and the number of Emergency Department visits during the previous year. None of the characteristics were statistically significantly associated with child abuse. The Hague Protocol will not be improved by adding one or more of the characteristics that were investigated.

High-reliability gas-turbine combined-cycle development program: Phase II. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hecht, K.G.; Sanderson, R.A.; Smith, M.J.

This three-volume report presents the results of Phase II of the multiphase EPRI-sponsored High-Reliability Gas Turbine Combined-Cycle Development Program whose goal is to achieve a highly reliable gas turbine combined-cycle power plant, available by the mid-1980s, which would be an economically attractive baseload generation alternative for the electric utility industry. The Phase II program objective was to prepare the preliminary design of this power plant. This volume presents information of the reliability, availability, and maintainability (RAM) analysis of a representative plant and the preliminary design of the gas turbine, the gas turbine ancillaries, and the balance of plant including themore » steam turbine generator. To achieve the program goals, a gas turbine was incorporated which combined proven reliability characteristics with improved performance features. This gas turbine, designated the V84.3, is the result of a cooperative effort between Kraftwerk Union AG and United Technologies Corporation. Gas turbines of similar design operating in Europe under baseload conditions have demonstrated mean time between failures in excess of 40,000 hours. The reliability characteristics of the gas turbine ancillaries and balance-of-plant equipment were improved through system simplification and component redundancy and by selection of component with inherent high reliability. A digital control system was included with logic, communications, sensor redundancy, and mandual backup. An independent condition monitoring and diagnostic system was also included. Program results provide the preliminary design of a gas turbine combined-cycle baseload power plant. This power plant has a predicted mean time between failure of nearly twice the 3000-hour EPRI goal. The cost of added reliability features is offset by improved performance, which results in a comparable specific cost and an 8% lower cost of electricity compared to present market offerings.« less

Greenery in the university environment: Students’ preferences and perceived restoration likelihood

PubMed Central

2018-01-01

A large body of evidence shows that interaction with greenery can be beneficial for human stress reduction, emotional states, and improved cognitive function. It can, therefore, be expected that university students might benefit from greenery in the university environment. Before investing in real-life interventions in a university environment, it is necessary to first explore students’ perceptions of greenery in the university environment. This study examined (1) preference for university indoor and outdoor spaces with and without greenery (2) perceived restoration likelihood of university outdoor spaces with and without greenery and (3) if preference and perceived restoration likelihood ratings were modified by demographic characteristics or connectedness to nature in Dutch university students (N = 722). Digital photographic stimuli represented four university spaces (lecture hall, classroom, study area, university outdoor space). For each of the three indoor spaces there were four or five stimuli conditions: (1) the standard design (2) the standard design with a colorful poster (3) the standard design with a nature poster (4) the standard design with a green wall (5) the standard design with a green wall plus interior plants. The university outdoor space included: (1) the standard design (2) the standard design with seating (3) the standard design with colorful artifacts (4) the standard design with green elements (5) the standard design with extensive greenery. Multi-level analyses showed that students gave higher preference ratings to the indoor spaces with a nature poster, a green wall, or a green wall plus interior plants than to the standard designs and the designs with the colorful posters. Students also rated preference and perceived restoration likelihood of the outdoor spaces that included greenery higher than those without. Preference and perceived restoration likelihood were not modified by demographic characteristics, but students with strong connectedness to nature rated preference and perceived restoration likelihood overall higher than students with weak connectedness to nature. The findings suggest that students would appreciate the integration of greenery in the university environment. PMID:29447184

Greenery in the university environment: Students' preferences and perceived restoration likelihood.

PubMed

van den Bogerd, Nicole; Dijkstra, S Coosje; Seidell, Jacob C; Maas, Jolanda

2018-01-01

A large body of evidence shows that interaction with greenery can be beneficial for human stress reduction, emotional states, and improved cognitive function. It can, therefore, be expected that university students might benefit from greenery in the university environment. Before investing in real-life interventions in a university environment, it is necessary to first explore students' perceptions of greenery in the university environment. This study examined (1) preference for university indoor and outdoor spaces with and without greenery (2) perceived restoration likelihood of university outdoor spaces with and without greenery and (3) if preference and perceived restoration likelihood ratings were modified by demographic characteristics or connectedness to nature in Dutch university students (N = 722). Digital photographic stimuli represented four university spaces (lecture hall, classroom, study area, university outdoor space). For each of the three indoor spaces there were four or five stimuli conditions: (1) the standard design (2) the standard design with a colorful poster (3) the standard design with a nature poster (4) the standard design with a green wall (5) the standard design with a green wall plus interior plants. The university outdoor space included: (1) the standard design (2) the standard design with seating (3) the standard design with colorful artifacts (4) the standard design with green elements (5) the standard design with extensive greenery. Multi-level analyses showed that students gave higher preference ratings to the indoor spaces with a nature poster, a green wall, or a green wall plus interior plants than to the standard designs and the designs with the colorful posters. Students also rated preference and perceived restoration likelihood of the outdoor spaces that included greenery higher than those without. Preference and perceived restoration likelihood were not modified by demographic characteristics, but students with strong connectedness to nature rated preference and perceived restoration likelihood overall higher than students with weak connectedness to nature. The findings suggest that students would appreciate the integration of greenery in the university environment.

RTJ-303: Variable geometry, oblique wing supersonic aircraft

NASA Technical Reports Server (NTRS)

Antaran, Albert; Belete, Hailu; Dryzmkowski, Mark; Higgins, James; Klenk, Alan; Rienecker, Lisa

1992-01-01

This document is a preliminary design of a High Speed Civil Transport (HSCT) named the RTJ-303. It is a 300 passenger, Mach 1.6 transport with a range of 5000 nautical miles. It features four mixed-flow turbofan engines, variable geometry oblique wing, with conventional tail-aft control surfaces. The preliminary cost analysis for a production of 300 aircraft shows that flyaway cost would be 183 million dollars (1992) per aircraft. The aircraft uses standard jet fuel and requires no special materials to handle aerodynamic heating in flight because the stagnation temperatures are approximately 130 degrees Fahrenheit in the supersonic cruise condition. It should be stressed that this aircraft could be built with today's technology and does not rely on vague and uncertain assumptions of technology advances. Included in this report are sections discussing the details of the preliminary design sequence including the mission to be performed, operational and performance constraints, the aircraft configuration and the tradeoffs of the final choice, wing design, a detailed fuselage design, empennage design, sizing of tail geometry, and selection of control surfaces, a discussion on propulsion system/inlet choice and their position on the aircraft, landing gear design including a look at tire selection, tip-over criterion, pavement loading, and retraction kinematics, structures design including load determination, and materials selection, aircraft performance, a look at stability and handling qualities, systems layout including location of key components, operations requirements maintenance characteristics, a preliminary cost analysis, and conclusions made regarding the design, and recommendations for further study.

Summary of the ultrafiltration, reverse osmosis, and adsorbents project

NASA Astrophysics Data System (ADS)

Colvin, C. M.; Roberts, R. C.; Williams, M. K.

1983-01-01

The design for a medium size (40 gal/min) ultrafiltration (UF) membrane unit includes a schematic diagram, capital and operating costs, a list and discussion of the radioisotopes tested and the results achieved, operating parameters, and characteristics of the available membrane configurations. The plant design for a reverse osmosis (RO) membrane unit includes a conceptual diagram, specifications for a RO unit producing 40 gal/min of permeated product, a list of radioisotopes tested on RO units and the rejections achieved, a discussion of the principal of RO, a discussion of the upper limits of cation and anion concentrations (there are no lower limits), a discussion of membrane configurations and porosities, a discussion of factors affecting membranes, a section on calculating the membrane area needed for a particular application, and capital and operating cost calculations. The design for an ion exchange pilot plant includes a schematic diagram; flow, resin, and column specifications; impurity limits; and operating and capital costs. A short theoretical discussion and process description are also included. The design retains flexibility so that application to a specific stream can be determined.

Parallel particle impactor - novel size-selective particle sampler for accurate fractioning of inhalable particles

NASA Astrophysics Data System (ADS)

Trakumas, S.; Salter, E.

2009-02-01

Adverse health effects due to exposure to airborne particles are associated with particle deposition within the human respiratory tract. Particle size, shape, chemical composition, and the individual physiological characteristics of each person determine to what depth inhaled particles may penetrate and deposit within the respiratory tract. Various particle inertial classification devices are available to fractionate airborne particles according to their aerodynamic size to approximate particle penetration through the human respiratory tract. Cyclones are most often used to sample thoracic or respirable fractions of inhaled particles. Extensive studies of different cyclonic samplers have shown, however, that the sampling characteristics of cyclones do not follow the entire selected convention accurately. In the search for a more accurate way to assess worker exposure to different fractions of inhaled dust, a novel sampler comprising several inertial impactors arranged in parallel was designed and tested. The new design includes a number of separated impactors arranged in parallel. Prototypes of respirable and thoracic samplers each comprising four impactors arranged in parallel were manufactured and tested. Results indicated that the prototype samplers followed closely the penetration characteristics for which they were designed. The new samplers were found to perform similarly for liquid and solid test particles; penetration characteristics remained unchanged even after prolonged exposure to coal mine dust at high concentration. The new parallel impactor design can be applied to approximate any monotonically decreasing penetration curve at a selected flow rate. Personal-size samplers that operate at a few L/min as well as area samplers that operate at higher flow rates can be made based on the suggested design. Performance of such samplers can be predicted with high accuracy employing well-established impaction theory.

Friendliness, functionality and freedom: Design characteristics that support midwifery practice in the hospital setting.

PubMed

Hammond, Athena; Homer, Caroline S E; Foureur, Maralyn

2017-07-01

to identify and describe the design characteristics of hospital birth rooms that support midwives and their practice. this study used a qualitative exploratory descriptive methodology underpinned by the theoretical approach of critical realism. Data was collected through 21 in-depth, face-to-face photo-elicitation interviews and a thematic analysis guided by study objectives and the aims of exploratory research was undertaken. the study was set at a recently renovated tertiary hospital in a large Australian city. participants were 16 registered midwives working in a tertiary hospital; seven in delivery suite and nine in birth centre settings. Experience as a midwife ranged from three to 39 years and the sample included midwives in diverse roles such as educator, student support and unit manager. three design characteristics were identified that supported midwifery practice. They were friendliness, functionality and freedom. Friendly rooms reduced stress and increased midwives' feelings of safety. Functional rooms enabled choice and provided options to better meet the needs of labouring women. And freedom allowed for flexible, spontaneous and responsive midwifery practice. hospital birth rooms that possess the characteristics of friendliness, functionality and freedom offer enhanced support for midwives and may therefore increase effective care provision. new and existing birth rooms can be designed or adapted to better support the wellbeing and effectiveness of midwives and may thereby enhance the quality of midwifery care delivered in the hospital. Quality midwifery care is associated with positive outcomes and experiences for labouring women. Further research is required to investigate the benefit that may be transmitted to women by implementing design intended to support and enhance midwifery practice. Copyright © 2017 Elsevier Ltd. All rights reserved.

Piloted Simulation Investigation of a Supersonic Transport Configuration (LaRC.4)

NASA Technical Reports Server (NTRS)

Jackson, E. Bruce; Martinez, Debbie; Derry, Stephen D.

1999-01-01

This report contains a description of the test facilities and software utilized during a joint NASA/aerospace industry study of improved control laws and desired inceptor characteristics for a candidate supersonic transport air-craft design. Details concerning the characteristics of the simulation cockpit, image generator and display systems, and motion platform are described. Depictions of the various display formats are included. The test schedule, session log, and flight cards describing the maneuvers performed is included. A brief summary of high-lights of the study is given. Modifications made to the industry-provided simulation model are described. This report is intended to serve as a reference document for industry researchers.

Estimation Model of Spacecraft Parameters and Cost Based on a Statistical Analysis of COMPASS Designs

NASA Technical Reports Server (NTRS)

Gerberich, Matthew W.; Oleson, Steven R.

2013-01-01

The Collaborative Modeling for Parametric Assessment of Space Systems (COMPASS) team at Glenn Research Center has performed integrated system analysis of conceptual spacecraft mission designs since 2006 using a multidisciplinary concurrent engineering process. The set of completed designs was archived in a database, to allow for the study of relationships between design parameters. Although COMPASS uses a parametric spacecraft costing model, this research investigated the possibility of using a top-down approach to rapidly estimate the overall vehicle costs. This paper presents the relationships between significant design variables, including breakdowns of dry mass, wet mass, and cost. It also develops a model for a broad estimate of these parameters through basic mission characteristics, including the target location distance, the payload mass, the duration, the delta-v requirement, and the type of mission, propulsion, and electrical power. Finally, this paper examines the accuracy of this model in regards to past COMPASS designs, with an assessment of outlying spacecraft, and compares the results to historical data of completed NASA missions.

ENGINEERING AND CONSTRUCTING THE HALLAM NUCLEAR POWER FACILITY REACTOR STRUCTURE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahlmeister, J E; Haberer, W V; Casey, D F

1960-12-15

The Hallam Nuclear Power Facility reactor structure, including the cavity liner, is described, and the design philosophy and special design requirements which were developed during the preliminary and final engineering phases of the project are explained. The structure was designed for 600 deg F inlet and 1000 deg F outlet operating sodium temperatures and fabricated of austenitic and ferritic stainless steels. Support for the reactor core components and adequate containment for biological safeguards were readily provided even though quite conservative design philosophy was used. The calculated operating characteristics, including heat generation, temperature distributions and stress levels for full-power operation, aremore » summarized. Ship fabrication and field installation experiences are also briefly related. Results of this project have established that the sodium graphite reactor permits practical and economical fabrication and field erection procedures; considerably higher operating design temperatures are believed possible without radical design changes. Also, larger reactor structures can be similarly constructed for higher capacity (300 to 1000 Mwe) nuclear power plants. (auth)« less

Forest Community: An Ecological Study

ERIC Educational Resources Information Center

Zipko, Stephen J.

1974-01-01

Discusses science activities designed to examine a balanced community in an unspoiled wooded section, including the study of physical and floral characteristics, shrubs, small and large trees, and animals. Indicates that the students' awareness of man's place in nature and nature's place in man is enhanced through such activities. (CC)

Disorders of Articulation. Prentice-Hall Foundations of Speech Pathology Series.

ERIC Educational Resources Information Center

Carrell, James A.

Designed for students of speech pathology and audiology and for practicing clinicians, the text considers the nature of the articulation process, criteria for diagnosis, and classification and etiology of disorders. Also discussed are phonetic characteristics, including phonemic errors and configurational and contextual defects; and functional…

Reliability techniques for computer executive programs

NASA Technical Reports Server (NTRS)

1972-01-01

Computer techniques for increasing the stability and reliability of executive and supervisory systems were studied. Program segmentation characteristics are discussed along with a validation system which is designed to retain the natural top down outlook in coding. An analysis of redundancy techniques and roll back procedures is included.

Student Questionnaire. [Harvard Project Physics

ERIC Educational Resources Information Center

Welch, Wayne W.; Ahlgren, Andrew

This 60-item questionnaire was designed to gather general background information from students who had used the Harvard Project Physics curriculum. The instrument includes three 20-item subscales: (1) attitude toward physics, (2) career interest, and (3) student characteristics. Items are multiple choice (5 options), and the introductory material…

The Many Faces of School-University Collaboration: Characteristics of Successful Partnerships.

ERIC Educational Resources Information Center

Ravid, Ruth, Ed.; Handler, Marianne G., Ed.

This book is designed to help educators entering into school-university collaborative relationships have a clearer picture of conditions that drive successful partnerships. The models described include collaboration between a university and professional development school, consultation, one-to-one collaborations, and multiple collaboration…

Evaluation Techniques for Individualized Instruction: Development and Formative Testing.

ERIC Educational Resources Information Center

Bedient, Douglas; And Others

1986-01-01

Steps used in the formative evaluation of a project designed to incorporate self-instructional materials in an introductory zoology course included techniques which: (1) involved colleagues in the material development; (2) assessed relevant student characteristics, expectations, and evaluations; and (3) were used in the examinations. (MBR)

Breath-Group Intelligibility in Dysarthria: Characteristics and Underlying Correlates

ERIC Educational Resources Information Center

Yunusova, Yana; Weismer, Gary; Kent, Ray D.; Rusche, Nicole M.

2005-01-01

Purpose: This study was designed to determine whether within-speaker fluctuations in speech intelligibility occurred among speakers with dysarthria who produced a reading passage, and, if they did, whether selected linguistic and acoustic variables predicted the variations in speech intelligibility. Method: Participants with dysarthria included a…

TISSUE ASSAYS AND POPULATION CHARACTERISTICS OF ROOSEVELT HOT SPRINGS' ANIMALS (1977-1978)

EPA Science Inventory

Geothermal energy exploration is being conducted at several locations in the United States including a site at Roosevelt Hot Springs in southwest Utah. To assess any possible impact and to help design a monitoring strategy for geothermal development, element concentrations in ani...

What Research Tells the Coach About Football.

ERIC Educational Resources Information Center

Paige, Roderick R.

This booklet is designed to make available research findings about football with interpretations for practical application. Chapter 1, "Physical Characteristics of Football Athletes," includes a table comparing the height and weight of National Football League players and All-Star players. Somatotyping and body composition are discussed. In…

High-efficiency helical traveling-wave tube with dynamic velocity taper and advanced multistage depressed collector

NASA Technical Reports Server (NTRS)

Curren, Arthur N.; Palmer, Raymond W.; Force, Dale A.; Dombro, Louis; Long, James A.

1987-01-01

A NASA-sponsored research and development contract has been established with the Watkins-Johnson Company to fabricate high-efficiency 20-watt helical traveling wave tubes (TWTs) operating at 8.4 to 8.43 GHz. The TWTs employ dynamic velocity tapers (DVTs) and advanced multistage depressed collectors (MDCs) having electrodes with low secondary electron emission characteristics. The TWT designs include two different DVTs; one for maximum efficiency and the other for minimum distortion and phase shift. The MDC designs include electrodes of untreated and ion-textured graphite as well as copper which has been treated for secondary electron emission suppression. Objectives of the program include achieving at least 55 percent overall efficiency. Tests with the first TWTs (with undepressed collectors) indicate good agreement between predicted and measured RF efficiencies with as high as 30 percent improvement in RF efficiency over conventional helix designs.

Package design and nutritional profile of foods targeted at children in supermarkets in Montevideo, Uruguay.

PubMed

Giménez, Ana; Saldamando, Luis de; Curutchet, María Rosa; Ares, Gastón

2017-06-12

Marketing of unhealthy products has been identified as one of the main characteristics of the food environment that negatively affects children's eating patterns. Restrictions on advertising of unhealthy foods to children have already been imposed in different countries. However, marketing strategies are not limited to broadcast and digital advertising, but also include package design. In this context, the current study aimed to describe the food products targeted at children and sold in supermarkets in Montevideo, Uruguay, in terms of package design and nutrient profile. Two supermarkets in Montevideo were selected for data collection. In each supermarket, all products targeted at children were identified. Products were analyzed in terms of package design and nutritional profile, considering the Pan American Health Organization Nutrient Profile Model. A total of 180 unique products were identified, which included a wide range of product categories. The great majority of the products corresponded to ultra-processed products with excessive amounts of sodium, free sugars, total fat, saturated fat, and/or trans fat, which are not recommended for frequent consumption. Several marketing strategies were identified in the design of packages to attract children's attention and drive their preferences. The most common strategies were the inclusion of cartoon characters, bright colors, childish lettering, and a wide range of claims related to health and nutrition, as well as the products' sensory and hedonic characteristics. The study's findings provide additional evidence on the need to regulate packaging of products targeted at children.

Full potential methods for analysis/design of complex aerospace configurations

NASA Technical Reports Server (NTRS)

Shankar, Vijaya; Szema, Kuo-Yen; Bonner, Ellwood

1986-01-01

The steady form of the full potential equation, in conservative form, is employed to analyze and design a wide variety of complex aerodynamic shapes. The nonlinear method is based on the theory of characteristic signal propagation coupled with novel flux biasing concepts and body-fitted mapping procedures. The resulting codes are vectorized for the CRAY XMP and the VPS-32 supercomputers. Use of the full potential nonlinear theory is demonstrated for a single-point supersonic wing design and a multipoint design for transonic maneuver/supersonic cruise/maneuver conditions. Achievement of high aerodynamic efficiency through numerical design is verified by wind tunnel tests. Other studies reported include analyses of a canard/wing/nacelle fighter geometry.

An RC active filter design handbook

NASA Technical Reports Server (NTRS)

Deboo, G. J.

1977-01-01

The design of filters is described. Emphasis is placed on simplified procedures that can be used by the reader who has minimum knowledge about circuit design and little acquaintance with filter theory. The handbook has three main parts. The first part is a review of some information that is essential for work with filters. The second part includes design information for specific types of filter circuitry and describes simple procedures for obtaining the component values for a filter that will have a desired set of characteristics. Pertinent information relating to actual performance is given. The third part (appendix) is a review of certain topics in filter theory and is intended to provide some basic understanding of how filters are designed.

Shock-free turbomachinery blade design

NASA Technical Reports Server (NTRS)

Beauchamp, P. P.; Seebass, A. R.

1985-01-01

A computational method for designing shock-free, quasi-three-dimensional, transonic, turbomachinery blades is described. Shock-free designs are found by implementing Sobieczky's fictitious gas principle in the analysis of a baseline shape, resulting in an elliptic solution that is incorrect in the supersonic domain. Shock-free designs are obtained by combining the subsonic portion of this solution with a characteristic calculation of the correct supersonic flow using the sonic line data from the fictitious elliptic solution. This provides a new, shock-free blade design. Examples presented include the removal of shocks from two blades in quasi-three-dimensional flow and the development of a series of shock-free two-dimensional stators. The new designs all include modifications to the upper surface of an experimental stator blade developed at NASA Lewis Research Center. While the designs presented here are for inviscid flow, the same concepts have been successfully applied to the shock-free design of airfoils and three-dimensional wings with viscous effects. The extension of the present method to viscous flows is straightforward given a suitable analysis algorithm for the flow.

Quiet Clean Short-haul Experimental Engine (QCSEE): Hamilton Standard cam/harmonic drive variable pitch fan actuation system detail design report

NASA Technical Reports Server (NTRS)

1976-01-01

A variable pitch fan actuation system was designed which incorporates a remote nacelle-mounted blade angle regulator. The regulator drives a rotating fan-mounted mechanical actuator through a flexible shaft and differential gear train. The actuator incorporates a high ratio harmonic drive attached to a multitrack spherical cam which changes blade pitch through individual cam follower arms attached to each blade trunnion. Detail design parameters of the actuation system are presented. These include the following: design philosophies, operating limits, mechanical, hydraulic and thermal characteristics, mechanical efficiencies, materials, weights, lubrication, stress analyses, reliability and failure analyses.

Application of a Computer Model to Various Specifications of Fuel Injection System for DI Diesel Engines

NASA Astrophysics Data System (ADS)

Yamanishi, Manabu

A combined experimental and computational investigation was performed in order to evaluate the effects of various design parameters of an in-line injection pump on the nozzle exit characteristics for DI diesel engines. Measurements of the pump chamber pressure and the delivery valve lift were included for validation by using specially designed transducers installed inside the pump. The results confirm that the simulation model is capable of predicting the pump operation for all the different designs investigated pump operating conditions. Following the successful validation of this model, parametric studies were performed which allow for improved fuel injection system design.

Regenerative fuel cell systems for space station

NASA Technical Reports Server (NTRS)

Hoberecht, M. A.; Sheibley, D. W.

1985-01-01

Regenerative fuel cell (RFC) systems are the leading energy storage candidates for Space Station. Key design features are the advanced state of technology readiness and high degree of system level design flexibility. Technology readiness was demonstrated through testing at the single cell, cell stack, mechanical ancillary component, subsystem, and breadboard levels. Design flexibility characteristics include independent sizing of power and energy storage portions of the system, integration of common reactants with other space station systems, and a wide range of various maintenance approaches. The design features led to selection of a RFC system as the sole electrochemical energy storage technology option for the space station advanced development program.

Streamflow characteristics of the Colorado River Basin in Utah through September 1981

USGS Publications Warehouse

Christensen, R.C.; Johnson, E.B.; Plantz, G.G.

1987-01-01

 This report summarizes discharge data and other streamflow characteristics developed from gag ing-station records collected through September 1981 at 337 stations in the Colorado River Basin in Utah. Data also are included for 14 stations in adjacent areas of the bordering states of Arizona, Colorado, and Wyoming (fig. 1). The study leading to this report was done in cooperation with the U.S. Bureau of Land Management, which needs the streamflow data in order to evaluate impacts of mining on the hydrologic system. The report also will be beneficial to other Federal, State, and county agencies and to individuals concerned with water supply and water problems in the Colorado River Basin.The streamflow characteristics in the report could be useful in many water-related studies that involve the following:Definition of baseline-hydrologic conditions; studies of the effects of man's activities on streamflow; frequency analyses of low and high flows; regional analyses of streamflow characteristics; design of water-supply systems; water-power studies; forecasting of stream discharge; time-series analyses of streamflow; design of flood-control structures; stream-pollution studies; and water-chemistry transport studies.The basic data used to develop the summaries in this report are records of daily and peak discharge collected by the U.S. Geological Survey and other Federal agencies. Much of the work of the Geological Survey was done in cooperation with Federal, State, and county agencies. Discharge recordsincluded in the report generally were for stations with at least 1 complete water year of record and nearby stations that were on the same stream and had different streamflow characteristics. A water year is a 12-month period ending September 30, and it is designated by the calendar year in which it ends. For streams that have had significant changes in regulation by reservoirs or diversions, the records before and after those changes were used separately to provide streamflow characteristics for each period of homogeneous streamflow and to show the change in the characteristics. Summaries for annual peak discharge are included only for stations with 5 or more years of data. The summaries of annual lowest and highest mean-discharge frequency are reported for stations with 10 or more years of daily-discharge record and for which computer-generated frequency curves provided a reasonable fit of the plotted data.

Preliminary Evaluation of the Low-Speed Stability and Control Characteristics of the McDonnell XP-85 Airplane from Tests of an Unballasted 1/5-Scale Model in the Langley Free-Flight Tunnel

NASA Technical Reports Server (NTRS)

Paulson, John W.; Johnson, Joseph L.

1947-01-01

At the request of the Air Material Command, Army Air Forces an investigation of the low-speed, power-off stability and control characteristics of the McDonnell XP-85 airplane is being conducted in the Langley free-flight tunnel. The XP-85 airplane is a jet propelled, parasite fighter with a 34 deg sweepback at the wing quarter chord. It was designed to be carried in a bomb bay of the B-36 air plane. The first portion of the investigation consists of a preliminary evaluation of the stability and control characteristics of the airplane from force and fight tests of an unballasted 1/5-scale model. The second portion of the investigation consists of test of a properly balasted 1/10-scale model which will include a study of the stability of the Xp-85 when attached to the trapeze for retraction into the B-36 bomb bay. The results of the preliminary test with the 1/5-scale model are presented herein. This portion fo the investigation included tests of the model with various center fin arrangements. Both the design nose flap and a stall control vane were investigated.

Conceptual design of thermal energy storage systems for near-term electric utility applications

NASA Technical Reports Server (NTRS)

Hall, E. W.

1980-01-01

Promising thermal energy storage systems for midterm applications in conventional electric utilities for peaking power generation are evaluated. Conceptual designs of selected thermal energy storage systems integrated with conventional utilities are considered including characteristics of alternate systems for peaking power generation, viz gas turbines and coal fired cycling plants. Competitive benefit analysis of thermal energy storage systems with alternate systems for peaking power generation and recommendations for development and field test of thermal energy storage with a conventional utility are included. Results indicate that thermal energy storage is only marginally competitive with coal fired cycling power plants and gas turbines for peaking power generation.

Hypersonic airbreathing vehicle visions and enhancing technologies

NASA Astrophysics Data System (ADS)

Hunt, James L.; Lockwood, Mary Kae; Petley, Dennis H.; Pegg, Robert J.

1997-01-01

This paper addresses the visions for hypersonic airbreathing vehicles and the advanced technologies that forge and enhance the designs. The matrix includes space access vehicles (single-stage-to-orbit (SSTO), two-stage-to-orbit (2STO) and three-stage-to-orbit (3STO)) and endoatmospheric vehicles (airplanes—missiles are omitted). The characteristics, the performance potential, the technologies and the synergies will be discussed. A common design constraint is that all vehicles (space access and endoatmospheric) have enclosed payload bays.

Large angle magnetic suspension text fixture

NASA Technical Reports Server (NTRS)

Britcher, Colin P.

1995-01-01

In lieu of a final report for this project for the period 1 April 1995 through 31 October 1995, a compilation of three reports are included herein. The three reports are: (1) 'Design and Implementation of a Digital Controller for a Magnetic Suspension and Vernier Pointing System', (2) 'Influence of Eddy Currents on the Dynamic Characteristics of Magnetic Suspensions and Magnetic Bearings', and (3) 'Design and Implementation of a Digital Controller for a Magnetic Suspension and Vernier Pointing System'.

JT9D ceramic outer air seal system refinement program

NASA Technical Reports Server (NTRS)

Gaffin, W. O.

1982-01-01

The abradability and durability characteristics of the plasma sprayed system were improved by refinement and optimization of the plasma spray process and the metal substrate design. The acceptability of the final seal system for engine testing was demonstrated by an extensive rig test program which included thermal shock tolerance, thermal gradient, thermal cycle, erosion, and abradability tests. An interim seal system design was also subjected to 2500 endurance test cycles in a JT9D-7 engine.

Optimal Micro-Jet Flow Control for Compact Air Vehicle Inlets

NASA Technical Reports Server (NTRS)

Anderson, Bernhard H.; Miller, Daniel N.; Addington, Gregory A.; Agrell, Johan

2004-01-01

The purpose of this study on micro-jet secondary flow control is to demonstrate the viability and economy of Response Surface Methodology (RSM) to optimally design micro-jet secondary flow control arrays, and to establish that the aeromechanical effects of engine face distortion can also be included in the design and optimization process. These statistical design concepts were used to investigate the design characteristics of "low mass" micro-jet array designs. The term "low mass" micro-jet may refers to fluidic jets with total (integrated) mass flow ratios between 0.10 and 1.0 percent of the engine face mass flow. Therefore, this report examines optimal micro-jet array designs for compact inlets through a Response Surface Methodology.

Acoustic Characteristics of Various Treatment Panel Designs for HSCT Ejector Liner Acoustic Technology Development Program

NASA Technical Reports Server (NTRS)

Salikuddin, M.; Kraft, R. E.; Syed, A. a.; Vu, D. D.; Mungur, P.; Langenbrunner, L. E.; Majjigi, R. K.

2006-01-01

The objectives of the initial effort (Phase I) of HSR Liner Technology Program, the selection of promising liner concepts, design and fabrication of these concepts for laboratory tests, testing these liners in the laboratory by using impedance tube and flow ducts, and developing empirical impedance/suppression correlation, are successfully completed. Acoustic and aerodynamic criteria for the liner design are established. Based on these criteria several liners are designed. The liner concepts designed and fabricated include Single-Degree-of-Freedom (SDOF), Two-Degree-of-Freedom (2DOF), and Bulk Absorber. Two types of SDOF treatment are fabricated, one with a perforated type face plate and the other with a wiremesh (woven) type faceplate. In addition, special configurations of these concepts are also included in the design. Several treatment panels are designed for parametric study. In these panels the facesheets of different porosity, hole diameter, and sheet thickness are utilized. Several deep panels (i.e., 1 in. deep) are designed and instrumented to measure DC flow resistance and insitu impedance in the presence of grazing flow. Basic components of these panels (i.e., facesheets, bulk materials, etc.) are also procured and tested. The results include DC flow resistance, normal impedance, and insertion loss.

Preliminary subsystem designs for the Assured Crew Return Vehicle (ACRV)

NASA Technical Reports Server (NTRS)

1990-01-01

Described herein is a series of design studies concerning the Assured Crew Return Vehicle (ACRV). Study topics include a braking and landing system for the ACRV, ACRV growth options, and the design impacts of ACRV's role as a medical emergency vehicle. Four alternate designs are presented for the ACRV braking and landing system. Options presented include ballistic and lifting body reentries; the use of high-lift, high-payload aerodynamic decelerators, as well as conventional parachutes; landing systems designed for water landings, land landings or both; and an aerial recovery system. Uses of the ACRV or a similarly designed vehicle in several roles for possible future space missions are discussed, along with the required changes to the ACRV to allow it to perform these missions optimally. The impacts on the design of the ACRV due to its role as an emergency vehicle were studied and are presented here. This study included the design of a stretcher-like system to transport an ill or injured crewmember safely within the ACRV; a compilation of necessary medical equipment and decisions on how or where to store it; and recommendations about internal and external vehicle characteristics that will ease the transport of the ill or injured crewmember and allow for swift and easy ingress/egress of the vehicle.

Optimization of rotor blades for combined structural, dynamic, and aerodynamic properties

NASA Technical Reports Server (NTRS)

He, Cheng-Jian; Peters, David A.

1990-01-01

Optimal helicopter blade design with computer-based mathematical programming has received more and more attention in recent years. Most of the research has focused on optimum dynamic characteristics of rotor blades to reduce vehicle vibration. There is also work on optimization of aerodynamic performance and on composite structural design. This research has greatly increased our understanding of helicopter optimum design in each of these aspects. Helicopter design is an inherently multidisciplinary process involving strong interactions among various disciplines which can appropriately include aerodynamics; dynamics, both flight dynamics and structural dynamics; aeroelasticity: vibrations and stability; and even acoustics. Therefore, the helicopter design process must satisfy manifold requirements related to the aforementioned diverse disciplines. In our present work, we attempt to combine several of these important effects in a unified manner. First, we design a blade with optimum aerodynamic performance by proper layout of blade planform and spanwise twist. Second, the blade is designed to have natural frequencies that are placed away from integer multiples of the rotor speed for a good dynamic characteristics. Third, the structure is made as light as possible with sufficient rotational inertia to allow for autorotational landing, with safe stress margins and flight fatigue life at each cross-section, and with aeroelastical stability and low vibrations. Finally, a unified optimization refines the solution.

Characteristics of the Japanese Diet Described in Epidemiologic Publications: A Qualitative Systematic Review.

PubMed

Suzuki, Nozomu; Goto, Yoshihito; Ota, Haruka; Kito, Kumiko; Mano, Fumika; Joo, Erina; Ikeda, Kaori; Inagaki, Nobuya; Nakayama, Takeo

2018-01-01

International interest in the Japanese diet has grown in recent years. The aim of this systematic review was to evaluate and organize the Japanese diet and dietary characteristics from an epidemiological perspective, mainly focusing on the nutritional and dietary elements. PubMed, Web of Science, Japan Medical Abstracts Society, JDream III, and CiNii databases were searched. The eligibility criteria included research with an epidemiological study design that was either cross-sectional, cohort, or case-control-based that defined the dietary patterns of the Japanese diet using dietary pattern analysis. A total of 39 research articles that described the Japanese diet were included. The data that were extracted included the following: implementing country, location, study design, participant characteristics, key outcomes, methods used in the analysis of dietary patterns, and descriptions of the Japanese diet. As a result of the systematic review analyzing the descriptions of the Japanese diet from 39 selected articles, we were able to aggregate the descriptions into 16 categories from 33 factors. After performing a content analysis using a further aggregation of categories, we found that the top three applicable categories were soybeans/soybean-derived products, seafood, and vegetables; these were followed by rice and miso soup. The Japanese dietary content was found to be diverse based on an examination of epidemiological studies; however, we were able to aggregate the content into 16 categories. The Japanese diet is considered to be a dietary pattern that contains a combination of factors: the dietary staple, side dishes, and soup.

Liquid Rocket Booster (LRB) for the Space Transportation System (STS) systems study. Appendix G: LRB for the STS system study level 2 requirements, revision 1

NASA Technical Reports Server (NTRS)

1989-01-01

Requirements are presented for shuttle system definition; performance and design characteristics; shuttle vehicle end item performance and design characteristics; ground operations complex performance and design characteristics; operability and system design and construction standards; and quality control.

Comparing Personal Characteristic Factors of Imagination between Expert and Novice Designers within Different Product Design Stages

ERIC Educational Resources Information Center

Huang, Yinghsiu; Li, Jianyou

2015-01-01

Imagination plays a key role in various domains in helping to create innovative ideas, drawings, poems, movies, products, etc. In product design domain, the personal characteristics of imagination are crucial abilities for conceiving novel ideas during design processes. This study focuses on personal characteristic differences and similarities…

Testing high brightness LEDs relative to application environment

NASA Astrophysics Data System (ADS)

Singer, Jeffrey; Mangum, Scott; Lundberg, John

2006-08-01

Application of light emitting diodes is expanding as the luminous output and efficiencies of these devices improve. At the same time, the number of LED package types is increasing, making it challenging to determine the appropriate device for use in lighting product designs. A range of factors should be considered when selecting a LED for an application including color coordinates, luminous efficacy, cost, lumen maintenance, application life, packaging and manufacturability. Additional complexities can be introduced as LED packages become obsolete and replacement parts must be selected. The replacement LED characteristics must be understood and assessed against the parameters of the original device, in order to determine if the change will be relatively simple or will force other end-product changes. While some characteristics are readily measured and compared, other factors, such as lumen maintenance, are difficult to verify. This paper will discuss the characteristics of a LED that should be considered during the design process as well as methods to validate these characteristics, particularly those which are not typically on data sheets or, are critical to the design and warrant additional validation. Particular attention will be given to LED lumen maintenance. While published manufacturer data typically provides temperature versus performance curves, the data may not be useful depending upon the application's operating environment. Models must be created to estimate the LED's junction temperature and degradation curve at the applied temperature in order to develop a more precise life estimate. This paper presents one approach to a LED device life and performance study designed with application environments in mind.

Truck characteristics for use in highway design and operation. Volume II, Appendices

DOT National Transportation Integrated Search

1990-08-01

Highway geometric design and traffic operations are based in part on consideration of vehicle characteristics. However, many of the current highway design and operational criteria are based on passenger car characteristics, even though truck characte...

A Chemist's View of Labeling Hazardous Materials as Required by the U.S. Department of Transportation.

ERIC Educational Resources Information Center

Shurpik, Anton J.; Beim, Howard J.

1982-01-01

Discusses characteristics of materials and labels used by the Department of Transportation, including label design and color: red (flammable and spontaneously combustible), white/yellow (radioactives), orange (explosives), white (poisons), yellow (oxidizers), green (non-flammable gas), black/white (corrosive), blue (dangerous when wet). Includes…

Developing a Large Lexical Database for Information Retrieval, Parsing, and Text Generation Systems.

ERIC Educational Resources Information Center

Conlon, Sumali Pin-Ngern; And Others

1993-01-01

Important characteristics of lexical databases and their applications in information retrieval and natural language processing are explained. An ongoing project using various machine-readable sources to build a lexical database is described, and detailed designs of individual entries with examples are included. (Contains 66 references.) (EAM)

Tax Exemption Issues Facing Academic Health Centers in the Managed Care Environment.

ERIC Educational Resources Information Center

Jones, Darryll K.

1997-01-01

Traditional characteristics of academic health centers are outlined, and conflicts with managed care are identified. Operating strategies designed to resolve the conflicts are discussed in light of tax statutes and regulations, Internal Revenue Service interpretations, and case law. Detailed references are included to provide a complete resource…

10 CFR 100.10 - Factors to be considered when evaluating sites.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Section 100.10 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) REACTOR SITE CRITERIA Evaluation Factors for Stationary Power Reactor Site Applications Before January 10, 1997 and for Testing Reactors § 100... include those relating both to the proposed reactor design and the characteristics peculiar to the site...

10 CFR 100.10 - Factors to be considered when evaluating sites.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Section 100.10 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) REACTOR SITE CRITERIA Evaluation Factors for Stationary Power Reactor Site Applications Before January 10, 1997 and for Testing Reactors § 100... include those relating both to the proposed reactor design and the characteristics peculiar to the site...

Characteristics of Home: Perspectives of Women Who Are Homeless

ERIC Educational Resources Information Center

Walsh, Christine A.; Rutherford, Gayle E.; Kuzmak, Natasha

2009-01-01

We employed participatory, community-based research methods to explore the perceptions of home among women who are homeless. Twenty women engaged in one or more techniques including qualitative interviews, digital story telling, creative writing, photovoice, and design charrette to characterize their perceptions of home. Analysis of the data…

Arcade Video Games: Proxemic, Cognitive and Content Analyses.

ERIC Educational Resources Information Center

Braun, Claude M. J.; Giroux, Josette

1989-01-01

A study was designed to determine psychological complexity and reinforcement characteristics of popular arcade video games, including sex differences in game content, clientele social structure, human-to-human interaction contingencies, and value content. Results suggest a need for public control of children's access to the games and the video…

Stream Studies.

ERIC Educational Resources Information Center

Hamilton City Board of Education (Ontario).

This manual provides teachers with some knowledge of ecological study methods and techniques used in collecting data when plants and animals are studied in the field. Most activities deal with the interrelatedness of plant and animal life to the structure and characteristics of a stream and pond. Also included in this unit plan designed for the…

Crocodiles and Alligators. Young Discovery Library Series.

ERIC Educational Resources Information Center

Farre, Marie

This book is written for children ages 5 through 10. Part of a series designed to develop their curiosity, fascinate them and educate them, this volume describes the physical characteristics, behavior, and peculiar habits of crocodiles, including how to distinguish them from close relatives such as alligators, cayman, and gharials. (YP)

Primary Treatment and Sludge Digestion Workshop.

ERIC Educational Resources Information Center

Ontario Ministry of the Environment, Toronto.

This manual was developed for use at workshops designed to upgrade the knowledge of experienced wastewater treatment plant operators. Each of the sixteen lessons has clearly stated behavioral objectives to tell the trainee what he should know or do after completing that topic. Areas covered in this manual include: sewage characteristics;…

Physical Education. A Program For All Seasons. Grades 7-12.

ERIC Educational Resources Information Center

Idaho State Dept. of Education, Boise. Div. of Instructional Improvement.

This curriculum guide provides the basis for planning physical education programs for seventh through twelfth grade students in Idaho. Included are: (1) philosophy, goals and objectives, and guiding principles; (2) introduction to junior and high school student characteristics with implications for physical education program design; (3) a 135-item…

Send Your Students to Mars for Their next Research Project

ERIC Educational Resources Information Center

Lindgren, Charles

2006-01-01

The NASA's Mars Student Imaging Project (MSIP) is led by the Arizona State University (ASU) Mars Education Program, a major partner of NASA's Mars Exploration Program. MSIP is based on the National Science Education Standards and includes curriculum on terrestrial planet characteristics, experimental design, and proposal writing. Three spacecraft…

Counseling the Adult Basic Education Student.

ERIC Educational Resources Information Center

Champagne, Delight E.

This guide is designed for use by counselors and teachers working with adult basic education (ABE) students. Discussed first is the importance of viewing adult learners as clients. The unique characteristics of the ABE student are examined. Presented next is an adult counseling model that includes the following program participation phases:…

Lunar Surface Mission Operations Scenario and Considerations

NASA Technical Reports Server (NTRS)

Arnold, Larissa S.; Torney, Susan E.; Rask, John Doug; Bleisath, Scott A.

2006-01-01

Planetary surface operations have been studied since the last visit of humans to the Moon, including conducting analog missions. Mission Operations lessons from these activities are summarized. Characteristics of forecasted surface operations are compared to current human mission operations approaches. Considerations for future designs of mission operations are assessed.

Raising Beetles in a Classroom.

ERIC Educational Resources Information Center

Hackett, Erla

This guide is designed to provide elementary school teachers with a harmless, inexpensive, clean, odorless, and easy-to-care-for insect-rearing project for the classroom. The following topics are included: (1) instructions for the care and feeding of the beetle larvae; (2) student activities for observing larval characteristics and behavior…

CATSKILL AREA PROJECT IN SMALL SCHOOL DESIGN.

ERIC Educational Resources Information Center

Catskill Area Project in Small School Design, Oneonta, NY.

CHARACTERISTICS OF THE SMALL SCHOOL, AS PROPOSED BY THE PROJECT, ARE LISTED. FIVE AREAS OF SCHOOL OPERATION ARE DISCUSSED IN DETAIL--(1) MULTIPLE CLASSES, INCLUDING SUPERVISED CORRESPONDENCE COURSES, (2) FLEXIBLE SCHEDULES, (3) USE OF SCHOOL AIDES, (4) USES OF ELECTRONIC COMMUNICATION, AND (5) SHARED SERVICES AND TALENTED YOUTH. A MAP LOCATING THE…

An Equal Employment Opportunity Sensitivity Workshop

ERIC Educational Resources Information Center

Patten, Thomas H., Jr.; Dorey, Lester E.

1972-01-01

The equal employment opportunity sensitivity workshop seems to be a useful training device for getting an organization started on developing black and white change agents. A report on the establishment of such a workshop at the U.S. Army Tank Automotive Command (TACOM). Includes charts of design, characteristics, analysis of results, program…

A light-up probe with aggregation-induced emission characteristics (AIE) for selective imaging, naked-eye detection and photodynamic killing of Gram-positive bacteria.

PubMed

Feng, Guangxue; Yuan, Youyong; Fang, Hu; Zhang, Ruoyu; Xing, Bengang; Zhang, Guanxin; Zhang, Deqing; Liu, Bin

2015-08-11

We report the design and synthesis of a red fluorescent AIE light-up probe for selective recognition, naked-eye detection, and image-guided photodynamic killing of Gram-positive bacteria, including vancomycin-resistant Enterococcus strains.

Split-remerge method for eliminating processing window artifacts in recursive hierarchical segmentation

NASA Technical Reports Server (NTRS)

Tilton, James C. (Inventor)

2010-01-01

A method, computer readable storage, and apparatus for implementing recursive segmentation of data with spatial characteristics into regions including splitting-remerging of pixels with contagious region designations and a user controlled parameter for providing a preference for merging adjacent regions to eliminate window artifacts.

Television Sweep Circuits and Picture Signal Path; Radio and Television Service--Advanced: 9787.02.

ERIC Educational Resources Information Center

Dade County Public Schools, Miami, FL.

This course outline is designed to give students a working knowledge of radio and television theory and servicing techniques. Course content includes goals, specific block objectives, resistance-capacitance circuit characteristics, sawtooth generators sawtooth generator control and production of scanning waveforms, deflection systems, composite…

Post-Traumatic Stress Disorder among School Age Palestinian Children

ERIC Educational Resources Information Center

Khamis, Vivian

2005-01-01

Objectives: This study was designed to assess the prevalence of PTSD among Palestinian school-age children. Variables that distinguish PTSD and non-PTSD children were examined, including child characteristics, socioeconomic status, family environment, and parental style of influence. Method: Participants were 1,000 children aged 12 to 16 years.…

Seniors' Online Communities: A Quantitative Content Analysis

ERIC Educational Resources Information Center

Nimrod, Galit

2010-01-01

Purpose: To examine the contents and characteristics of seniors' online communities and to explore their potential benefits to older adults. Design and Methods: Quantitative content analysis of a full year's data from 14 leading online communities using a novel computerized system. The overall database included 686,283 messages. Results: There was…

Associations of Distance to Trauma Care, Community Income, and Neighborhood Median Age With Rates of Injury Mortality.

PubMed

Jarman, Molly P; Curriero, Frank C; Haut, Elliott R; Pollack Porter, Keshia; Castillo, Renan C

2018-02-07

Rural, low-income, and historically underrepresented minority communities face substantial barriers to trauma care and experience high injury incidence and mortality rates. Characteristics of injury incident locations may contribute to poor injury outcomes. To examine the association of injury scene characteristics with injury mortality. In this cross-sectional study, data from trauma center and emergency medical services provided by emergency medical services companies and designated trauma centers in the state of Maryland from January 1, 2015, to December 31, 2015, were geocoded by injury incident locations and linked with injury scene characteristics. Participants included adults who experienced traumatic injury in Maryland and were transported to a designated trauma center or died while in emergency medical services care at the incident scene or in transit. The primary exposures of interest were geographic characteristics of injury incident locations, including distance to the nearest trauma center, designation level and ownership status of the nearest trauma center, and land use, as well as community-level characteristics such as median age and per capita income. Odds of death were estimated with multilevel logistic regression, controlling for individual demographic measures and measures of injury and health. Of the 16 082 patients included in this study, 8716 (52.4%) were white, and 5838 (36.3%) were African American. Most patients were male (10 582; 65.8%) and younger than 65 years (12 383; 77.0%). Odds of death increased by 8.0% for every 5-mile increase in distance to the nearest trauma center (OR, 1.08; 95% CI, 1.01-1.15; P = .03). Compared with privately owned level 1 or 2 centers, odds of death increased by 49.9% when the nearest trauma center was level 3 (OR, 1.50; 95% CI, 1.06-2.11; P = .02), and by 80.7% when the nearest trauma center was publicly owned (OR, 1.81; 95% CI, 1.39-2.34; P < .001). At the zip code tabulation area level, odds of death increased by 16.0% for every 5-year increase in median age (OR, 1.16; 95% CI, 1.03-1.30; P = .02), and decreased by 26.6% when the per capita income was greater than $25 000 (OR, 0.73; 95% CI, 0.54-0.99; P = .05). Injury scene characteristics are associated with injury mortality. Odds of death are highest for patients injured in communities with higher median age or lower per capita income and at locations farthest from level 1 or 2 trauma centers.

Theoretical and Experimental Investigation of Mufflers with Comments on Engine-Exhaust Muffler Design

NASA Technical Reports Server (NTRS)

Davis, Don D , Jr; Stokes, George M; Moore, Dewey; Stevens, George L , Jr

1954-01-01

Equations are presented for the attenuation characteristics of single-chamber and multiple-chamber mufflers of both the expansion-chamber and resonator types, for tuned side-branch tubes, and for the combination of an expansion chamber with a resonator. Experimental curves of attenuation plotted against frequency are presented for 77 different mufflers with a reflection-free tailpipe termination. The experiments were made at room temperature without flow; the sound source was a loud-speaker. A method is given for including the tailpipe reflections in the calculations. Experimental attenuation curves are presented for four different muffler-tailpipe combinations, and the results are compared with the theory. The application of the theory to the design of engine-exhaust mufflers is discussed, and charts are included for the assistance of the designer.

Aeroelastic considerations for torsionally soft rotors

NASA Technical Reports Server (NTRS)

Mantay, W. R.; Yeager, W. T., Jr.

1985-01-01

A research study was initiated to systematically determine the impact of selected blade tip geometric parameters on conformable rotor performance and loads characteristics. The model articulated rotors included baseline and torsionally soft blades with interchangeable tips. Seven blade tip designs were evaluated on the baseline rotor and six tip designs were tested on the torsionally soft blades. The designs incorporated a systemmatic variation in geometric parameters including sweep, taper, and anhedral. The rotors were evaluated in the NASA Langley Transonic Dynamics Tunnel at several advance ratios, lift and propulsive force values, and tip Mach numbers. A track sensitivity study was also conducted at several advance ratios for both rotors. Based on the test results, tip parameter variations generated significant rotor performance and loads differences for both baseline and torsionally soft blades.

Quiet short-haul research aircraft familiarization document, revision 1

NASA Technical Reports Server (NTRS)

Eppel, J. C.

1981-01-01

The design features and general characteristics of the Quiet Short Haul Research Aircraft are described. Aerodynamic characteristics and performance are discussed based on predictions and early flight test data. Principle airplane systems, including the airborne data acquisition system, are also described. The aircraft was designed and built to fulfill the need for a national research facility to explore the use of upper surface blowing, propulsive lift technology in providing short takeoff and landing capability, and perform advanced experiments in various technical disciplines such as aerodynamics, propulsion, stability and control, handling qualities, avionics and flight control systems, trailing vortex phenomena, acoustics, structure and loads, operating systems, human factors, and airworthiness/certification criteria. An unusually austere approach using experimental shop practices resulted in a low cost and high research capability.

Quiet short-haul research aircraft familiarization document. [STOL

NASA Technical Reports Server (NTRS)

Mccracken, R. C.

1979-01-01

The design features and general characteristics of the NASA Quiet Short-Haul Research Aircraft are described. Aerodynamic characteristics and performance are discussed based on predictions and early flight-test data. Principle airplane systems, including the airborne data-acquisition system, are also described. The aircraft was designed and built to fulfill the need for a national research facility to explore the use of upper surface-blowing propulsive-lift technology in providing short takeoff and landing capability, and perform advanced experiments in various technical disciplines such as aerodynamics, propulsion, stability and control, handling qualities, avionics and flight-control systems, trailing-vortex phenomena, acoustics, structure and loads, operating systems, human factors, and airworthiness/certification criteria. An unusually austere approach using experimental shop practices resulted in a low cost and high research capability.

Receiver operating characteristic (ROC) curves: review of methods with applications in diagnostic medicine

NASA Astrophysics Data System (ADS)

Obuchowski, Nancy A.; Bullen, Jennifer A.

2018-04-01

Receiver operating characteristic (ROC) analysis is a tool used to describe the discrimination accuracy of a diagnostic test or prediction model. While sensitivity and specificity are the basic metrics of accuracy, they have many limitations when characterizing test accuracy, particularly when comparing the accuracies of competing tests. In this article we review the basic study design features of ROC studies, illustrate sample size calculations, present statistical methods for measuring and comparing accuracy, and highlight commonly used ROC software. We include descriptions of multi-reader ROC study design and analysis, address frequently seen problems of verification and location bias, discuss clustered data, and provide strategies for testing endpoints in ROC studies. The methods are illustrated with a study of transmission ultrasound for diagnosing breast lesions.

Titanium-doped sapphire laser research and design study

NASA Technical Reports Server (NTRS)

Moulton, Peter F.

1987-01-01

Three main topics were considered in this study: the fundamental laser parameters of titanium-doped sapphire, characterization of commercially grown material, and design of a tunable, narrow-linewidth laser. Fundamental parameters investigated included the gain cross section, upper-state lifetime as a function of temperature and the surface-damage threshold. Commercial material was found to vary widely in the level of absorption of the laser wavelength with the highest absorption in Czochralski-grown crystals. Several Yi:sapphire lasers were constructed, including a multimode laser with greater than 50mJ of output energy and a single-transverse-mode ring laser, whose spectral and temporal characteristics were completely characterized. A design for a narrow-linewidth (single-frequency) Ti:sapphire laser was developed, based on the results of the experimental work. The design involves the use of a single-frequency, quasi-cw master oscillator, employed as an injection source for a pulsed ring laser.

Realizing "2001: A Space Odyssey": Piloted Spherical Torus Nuclear Fusion Propulsion

NASA Technical Reports Server (NTRS)

Williams, Craig H.; Dudzinski, Leonard A.; Borowski, Stanley K.; Juhasz, Albert J.

2005-01-01

A conceptual vehicle design enabling fast, piloted outer solar system travel was created predicated on a small aspect ratio spherical torus nuclear fusion reactor. The initial requirements were satisfied by the vehicle concept, which could deliver a 172 mt crew payload from Earth to Jupiter rendezvous in 118 days, with an initial mass in low Earth orbit of 1,690 mt. Engineering conceptual design, analysis, and assessment was performed on all major systems including artificial gravity payload, central truss, nuclear fusion reactor, power conversion, magnetic nozzle, fast wave plasma heating, tankage, fuel pellet injector, startup/re-start fission reactor and battery bank, refrigeration, reaction control, communications, mission design, and space operations. Detailed fusion reactor design included analysis of plasma characteristics, power balance/utilization, first wall, toroidal field coils, heat transfer, and neutron/x-ray radiation. Technical comparisons are made between the vehicle concept and the interplanetary spacecraft depicted in the motion picture 2001: A Space Odyssey.

The design and development of a space laboratory to conduct magnetospheric and plasma research

NASA Technical Reports Server (NTRS)

Rosen, A.

1974-01-01

A design study was conducted concerning a proposed shuttle-borne space laboratory for research on magnetospheric and plasma physics. A worldwide survey found two broad research disciplines of interest: geophysical studies of the dynamics and structure of the magnetosphere (including wave characteristics, wave-particle interactions, magnetospheric modifications, beam-plasma interactions, and energetic particles and tracers) and plasma physics studies (plasma physics in space, wake and sheath studies, and propulsion and devices). The Plasma Physics and Environmental Perturbation Laboratory (PPEPL) designed to perform experiments in these areas will include two 50-m booms and two maneuverable subsatellites, a photometer array, standardized proton, electron, and plasma accelerators, a high-powered transmitter for frequencies above 100 kHz, a low-power transmitter for VLF and below, and complete diagnostic packages. Problem areas in the design of a space plasma physics laboratory are indicated.

An approach to constrained aerodynamic design with application to airfoils

NASA Technical Reports Server (NTRS)

Campbell, Richard L.

1992-01-01

An approach was developed for incorporating flow and geometric constraints into the Direct Iterative Surface Curvature (DISC) design method. In this approach, an initial target pressure distribution is developed using a set of control points. The chordwise locations and pressure levels of these points are initially estimated either from empirical relationships and observed characteristics of pressure distributions for a given class of airfoils or by fitting the points to an existing pressure distribution. These values are then automatically adjusted during the design process to satisfy the flow and geometric constraints. The flow constraints currently available are lift, wave drag, pitching moment, pressure gradient, and local pressure levels. The geometric constraint options include maximum thickness, local thickness, leading-edge radius, and a 'glove' constraint involving inner and outer bounding surfaces. This design method was also extended to include the successive constraint release (SCR) approach to constrained minimization.

Design and Testing of a One-Third Scale Soyuz TM Descent Module Spartan Conversion Project Super Loki Instrumentation

NASA Technical Reports Server (NTRS)

Anderson, Loren A.; Armitage, Pamela Kay

1993-01-01

The 1992-1993 senior Aerospace Engineering Design class continued work on the post landing configurations for the Assured Crew Return Vehicle. The Assured Crew Return Vehicle will be permanently docked to the space station fulfilling NASA's commitment of Assured Crew Return Capability in the event of an accident or illness aboard the space station. The objective of the project was to give the Assured Crew Return Vehicle Project Office data to feed into their feasibility studies. Three design teams were given the task of developing models with dynamically and geometrically scaled characteristics. Groups one and two combined efforts to design a one-third scale model of the Russian Soyuz TM Descent Module, and an on-board flotation system. This model was designed to determine the flotation characteristics and test the effects of a rigid flotation and orientation system. Group three designed a portable water wave test facility to be located on campus. Because of additional funding from Thiokol Corporation, testing of the Soyuz model and flotation systems took place at the Offshore Technology Research Center. Universities Space Research Association has been studying the use of small expendable launch vehicles for missions which cost less than 200 million dollars. The Crusader2B. which consists of the original Spartan first and second stage with an additional Spartan second stage and the Minuteman III upper stage is being considered for this task. University of Central Florida project accomplishments include an analysis of launch techniques, a modeling technique to determine flight characteristics, and input into the redesign of an existing mobile rail launch platform.

Feasibility study of an Integrated Program for Aerospace vehicle Design (IPAD). Volume 4: IPAD system design

NASA Technical Reports Server (NTRS)

Goldfarb, W.; Carpenter, L. C.; Redhed, D. D.; Hansen, S. D.; Anderson, L. O.; Kawaguchi, A. S.

1973-01-01

The computing system design of IPAD is described and the requirements which form the basis for the system design are discussed. The system is presented in terms of a functional design description and technical design specifications. The functional design specifications give the detailed description of the system design using top-down structured programming methodology. Human behavioral characteristics, which specify the system design at the user interface, security considerations, and standards for system design, implementation, and maintenance are also part of the technical design specifications. Detailed specifications of the two most common computing system types in use by the major aerospace companies which could support the IPAD system design are presented. The report of a study to investigate migration of IPAD software between the two candidate 3rd generation host computing systems and from these systems to a 4th generation system is included.

Extensions of D-optimal Minimal Designs for Symmetric Mixture Models.

PubMed

Li, Yanyan; Raghavarao, Damaraju; Chervoneva, Inna

2017-01-01

The purpose of mixture experiments is to explore the optimum blends of mixture components, which will provide desirable response characteristics in finished products. D-optimal minimal designs have been considered for a variety of mixture models, including Scheffé's linear, quadratic, and cubic models. Usually, these D-optimal designs are minimally supported since they have just as many design points as the number of parameters. Thus, they lack the degrees of freedom to perform the Lack of Fit tests. Also, the majority of the design points in D-optimal minimal designs are on the boundary: vertices, edges, or faces of the design simplex. Also a new strategy for adding multiple interior points for symmetric mixture models is proposed. We compare the proposed designs with Cornell (1986) two ten-point designs for the Lack of Fit test by simulations.

Person-based differences in pay reactions: A compensation-activation theory and integrative conceptual review.

PubMed

Fulmer, Ingrid Smithey; Shaw, Jason D

2018-06-07

Compensation research has focused traditionally on how pay design characteristics (e.g., pay level, individual or group incentives) relate to average employee outcomes and, in toto, on how these outcomes affect organizational performance. Recently, scholars have begun to pay more attention to how individuals vary in the strength of their reactions to pay. Empirical research in several disciplines examines how the interplay of pay systems and person-based characteristics (psychological individual differences, demographics, and relative performance or position in a group) relate to important work-related outcomes. We develop a compensation-activation theory that frames compensation design characteristics as workplace "situations" providing cues that activate individuals' corresponding fundamental social motives made salient due to chronic or transient person-based characteristics. Where activation occurs, stronger-than-average responses to the compensation "situation" are expected. Using the theory as a lens, we synthesize and reinterpret existing research on person-based reactions to pay characteristics, including sorting, incentive/motivational effects, and effects on collective pay system reactions and unit/organizational outcomes. We conclude with a research agenda aimed at refining compensation-activation theory and advancing the study of compensation as it affects individual and organizational outcomes. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

ULE design considerations for a 3m class light weighted mirror blank for E-ELT M5

NASA Astrophysics Data System (ADS)

Fox, Andrew; Hobbs, Tom; Edwards, Mary; Arnold, Matthew; Sawyer, Kent

2016-07-01

It is expected that the next generation of large ground based astronomical telescopes will need large fast-steering/tip-tilt mirrors made of ultra-lightweight construction. These fast-steering mirrors are used to continuously correct for atmospheric disturbances and telescope vibrations. An example of this is the European Extremely Large Telescope (E-ELT) M5 lightweight mirror, which is part of the Tip-Tilt/Field-Stabilization Unit. The baseline design for the E-ELT M5 mirror, as presented in the E-ELT Construction Proposal, is a closed-back ULE mirror with a lightweight core using square core cells. Corning Incorporated (Corning) has a long history of manufacturing lightweight mirror blanks using ULE in a closed-back construction, going back to the 1960's, and includes the Hubble Space Telescope primary mirror, Subaru Telescope secondary and tertiary mirrors, the Magellan I and II tertiary mirrors, and Kepler Space Telescope primary mirror, among many others. A parametric study of 1-meter class lightweight mirror designs showed that Corning's capability to seal a continuous back sheet to a light-weighted core structure provides superior mirror rigidity, in a near-zero thermal expansion material, relative to other existing technologies in this design space. Corning has investigated the parametric performance of several design characteristics for a 3-meter class lightweight mirror blank for the E-ELT M5. Finite Element Analysis was performed on several design scenarios to obtain weight, areal density, and first Eigen frequency. This paper presents an overview of Corning ULE and lightweight mirror manufacturing capabilities, the parametric performance of design characteristics for 1-meter class and 3-meter class lightweight mirrors, as well as the manufacturing advantages and disadvantages of those characteristics.

A systematic review of relations between neighborhoods and mental health.

PubMed

Truong, Khoa D; Ma, Sai

2006-09-01

The relationship between neighborhood characteristics and resident mental health has been widely investigated in individual studies in recent years, but this literature is not adequately reviewed. To systematically review relevant individual research of the relation between neighborhoods and adult mental health by identifying and synthesizing all relevant studies in this literature. We conducted an electronic search with PubMed and PsycINFO, and manual reference-checking, resulting in 8,562 screened studies of which 29 were selected. Studies were included in the main synthesis if they (i) were published in English in peer reviewed journals; (ii) had relevant definitions and measures of neighborhood characteristics; (iii) utilized standardized measures of adult mental health; (iv) controlled for individual characteristics; (v) reported quantitative results; and, (vi) studied a population in a developed country. We focused on two key areas within this literature: the methodologies utilized to study neighborhood effects and quantitative results. With regard to the former, we examined five major issues: (i) definitions and measures of neighborhoods; (ii) definitions and measures of mental health; (iii) controls for individual level characteristics; (iv) conceptual models; and (v) analytical models. As for quantitative results, the relation was reviewed by types of neighborhood characteristics. We summarized general quantitative findings and drew common conclusions across groups of studies. 27/29 studies found statistically significant association between mental health and at least one measure of neighborhood characteristics, after adjusting for individual factors. This association was evident for all types of neighborhood features, varying from sociodemographic characteristics to physical environment, and from objective to subjective measures. Neighborhood effects were weakened when adding individual-level characteristics into the regression models, and were generally modest relative to individual effects. Although the evidence is highly consistent across studies, detailed evaluation of each individual study reveals a complex reality. The included studies used various study designs and measures of mental health and neighborhoods, making generalization of their relationships less meaningful. It is not possible to conclude that studies with weaker controls for individual characteristics found stronger association between neighborhoods and mental health and vice versa. As only two studies used randomized and controlled trials, causal effects must be interpreted with caution. Formal meta-analysis techniques cannot be used due to large heterogeneity across the included studies. Efficient methods for quantitative analysis remain a great challenge. The current evidence suggests that efforts to improve mental health may be limited if only individual-level interventions are implemented. The calculation of the costs and benefits of neighborhood-level interventions deserves more attention. Moreover, policy makers may want to incorporate mental health as a measure for evaluating neighborhood improvement programs. There are not enough replicated or comparable studies in this literature to make more precise quantitative conclusions of this relation. Key aspects of study design and analyses could be improved to better understand the true nature of causal relationships. The data resolution of neighborhood characteristics needs to better match with the scale of neighborhood definition that is hypothesized to affect the residents' mental health. As experimental designs are rare in this area, thoughtful use of panel data, instrumental variable (IV) techniques, and other non-experimental approaches deserves further exploration.

Conceptual Design of the Everglades Depth Estimation Network (EDEN) Grid

USGS Publications Warehouse

Jones, John W.; Price, Susan D.

2007-01-01

INTRODUCTION The Everglades Depth Estimation Network (EDEN) offers a consistent and documented dataset that can be used to guide large-scale field operations, to integrate hydrologic and ecological responses, and to support biological and ecological assessments that measure ecosystem responses to the Comprehensive Everglades Restoration Plan (Telis, 2006). Ground elevation data for the greater Everglades and the digital ground elevation models derived from them form the foundation for all EDEN water depth and associated ecologic/hydrologic modeling (Jones, 2004, Jones and Price, 2007). To use EDEN water depth and duration information most effectively, it is important to be able to view and manipulate information on elevation data quality and other land cover and habitat characteristics across the Everglades region. These requirements led to the development of the geographic data layer described in this techniques and methods report. Relying on extensive experience in GIS data development, distribution, and analysis, a great deal of forethought went into the design of the geographic data layer used to index elevation and other surface characteristics for the Greater Everglades region. To allow for simplicity of design and use, the EDEN area was broken into a large number of equal-sized rectangles ('Cells') that in total are referred to here as the 'grid'. Some characteristics of this grid, such as the size of its cells, its origin, the area of Florida it is designed to represent, and individual grid cell identifiers, could not be changed once the grid database was developed. Therefore, these characteristics were selected to design as robust a grid as possible and to ensure the grid's long-term utility. It is desirable to include all pertinent information known about elevation and elevation data collection as grid attributes. Also, it is very important to allow for efficient grid post-processing, sub-setting, analysis, and distribution. This document details the conceptual design of the EDEN grid spatial parameters and cell attribute-table content.

High-frequency output characteristics of AlGaAs/GaAs heterojunction bipolar transistors for large-signal applications

NASA Astrophysics Data System (ADS)

Chen, J.; Gao, G. B.; Ünlü, M. S.; Morkoç, H.

1991-11-01

High-frequency ic- vce output characteristics of bipolar transistors, derived from calculated device cutoff frequencies, are reported. The generation of high-frequency output characteristics from device design specifications represents a novel bridge between microwave circuit design and device design: the microwave performance of simulated device structures can be analyzed, or tailored transistor device structures can be designed to fit specific circuit applications. The details of our compact transistor model are presented, highlighting the high-current base-widening (Kirk) effect. The derivation of the output characteristics from the modeled cutoff frequencies are then presented, and the computed characteristics of an AlGaAs/GaAs heterojunction bipolar transistor operating at 10 GHz are analyzed. Applying the derived output characteristics to microwave circuit design, we examine large-signal class A and class B amplification.

Study of the application of hydrogen fuel to long-range subsonic transport aircraft. Volume 1: Summary

NASA Technical Reports Server (NTRS)

Brewer, G. D.; Morris, R. E.; Lange, R. H.; Moore, J. W.

1975-01-01

The feasibility of using liquid hydrogen as fuel in advanced designs of long range, subsonic transport aircraft is assessed. Both passenger and cargo type aircraft are investigated. Comparisons of physical, performance, and economic parameters of the LH2 fueled designs with conventionally fueled aircraft are presented. Design studies are conducted to determine appropriate characteristics for the hydrogen related systems required on board the aircraft. These studies included consideration of material, structural, and thermodynamic requirements of the cryogenic fuel tanks and fuel systems with the structural support and thermal protection systems.

On the Design of Wide-Field X-ray Telescopes

NASA Technical Reports Server (NTRS)

Elsner, Ronald F.; O'Dell, Stephen L.; Ramsey, Brian D.; Weiskopf, Martin C.

2009-01-01

X-ray telescopes having a relatively wide field-of-view and spatial resolution vs. polar off-axis angle curves much flatter than the parabolic dependence characteristic of Wolter I designs are of great interest for surveys of the X-ray sky and potentially for study of the Sun s X-ray emission. We discuss the various considerations affecting the design of such telescopes, including the possible use of polynomial mirror surface prescriptions, a method of optimizing the polynomial coefficients, scaling laws for mirror segment length vs. intersection radius, the loss of on-axis spatial resolution, and the positioning of focal plane detectors.

Design and development of a multibeam 1.4 GHz pushbroom microwave radiometer

NASA Technical Reports Server (NTRS)

Lawrence, R. W.; Bailey, M. C.; Harrington, R. F.; Hearn, C. P.; Wells, J. G.; Stanley, W. D.

1986-01-01

The design and operation of a multiple beam, digital signal processing radiometer are discussed. The discussion includes a brief description of each major subsystem and an overall explanation of the hardware requirements and operation. A series of flight tests was conducted in which sea-truth sites, as well as an existing radiometer were used to verify the Pushbroom Radiometer performance. The results of these tests indicate that the Pushbroom Radiometer did meet the sensitivity design goal of 1.0 kelvin, and exceeded the accuracy requirement of 2.0 kelvin. Additional performance characteristics and test results are also presented.

Understanding the context of healthcare utilization: assessing environmental and provider-related variables in the behavioral model of utilization.

PubMed Central

Phillips, K A; Morrison, K R; Andersen, R; Aday, L A

1998-01-01

OBJECTIVE: The behavioral model of utilization, developed by Andersen, Aday, and others, is one of the most frequently used frameworks for analyzing the factors that are associated with patient utilization of healthcare services. However, the use of the model for examining the context within which utilization occurs-the role of the environment and provider-related factors-has been largely neglected. OBJECTIVE: To conduct a systematic review and analysis to determine if studies of medical care utilization that have used the behavioral model during the last 20 years have included environmental and provider-related variables and the methods used to analyze these variables. We discuss barriers to the use of these contextual variables and potential solutions. DATA SOURCES: The Social Science Citation Index and Science Citation Index. We included all articles from 1975-1995 that cited any of three key articles on the behavioral model, that included all articles that were empirical analyses and studies of formal medical care utilization, and articles that specifically stated their use of the behavioral model (n = 139). STUDY DESIGN: Design was a systematic literature review. DATA ANALYSIS: We used a structured review process to code articles on whether they included contextual variables: (1) environmental variables (characteristics of the healthcare delivery system, external environment, and community-level enabling factors); and (2) provider-related variables (patient factors that may be influenced by providers and provider characteristics that interact with patient characteristics to influence utilization). We also examined the methods used in studies that included contextual variables. PRINCIPAL FINDINGS: Forty-five percent of the studies included environmental variables and 51 percent included provider-related variables. Few studies examined specific measures of the healthcare system or provider characteristics or used methods other than simple regression analysis with hierarchical entry of variables. Only 14 percent of studies analyzed the context of healthcare by including both environmental and provider-related variables as well as using relevant methods. CONCLUSIONS: By assessing whether and how contextual variables are used, we are able to highlight the contributions made by studies using these approaches, to identify variables and methods that have been relatively underused, and to suggest solutions to barriers in using contextual variables. PMID:9685123

Demonstration of coal reburning for cyclone boiler NO{sub x} control. Appendix, Book 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Based on the industry need for a pilot-scale cyclone boiler simulator, Babcock Wilcox (B&W) designed, fabricated, and installed such a facility at its Alliance Research Center (ARC) in 1985. The project involved conversion of an existing pulverized coal-fired facility to be cyclone-firing capable. Additionally, convective section tube banks were installed in the upper furnace in order to simulate a typical boiler convection pass. The small boiler simulator (SBS) is designed to simulate most fireside aspects of full-size utility boilers such as combustion and flue gas emissions characteristics, fireside deposition, etc. Prior to the design of the pilot-scale cyclone boiler simulator,more » the various cyclone boiler types were reviewed in order to identify the inherent cyclone boiler design characteristics which are applicable to the majority of these boilers. The cyclone boiler characteristics that were reviewed include NO{sub x} emissions, furnace exit gas temperature (FEGT) carbon loss, and total furnace residence time. Previous pilot-scale cyclone-fired furnace experience identified the following concerns: (1) Operability of a small cyclone furnace (e.g., continuous slag tapping capability). (2) The optimum cyclone(s) configuration for the pilot-scale unit. (3) Compatibility of NO{sub x} levels, carbon burnout, cyclone ash carryover to the convection pass, cyclone temperature, furnace residence time, and FEGT.« less

Participation in psychosocial oncology and quality-of-life research: a systematic review.

PubMed

Wakefield, Claire E; Fardell, Joanna E; Doolan, Emma L; Aaronson, Neil K; Jacobsen, Paul B; Cohn, Richard J; King, Madeleine

2017-03-01

Quality-of-life and psychosocial oncology studies that have low participation might have less precision, less statistical power, and can have non-response bias. In this systematic Review, we searched MEDLINE, Embase, and PsycInfo, for paediatric studies published in 2010-15 and adults studies published 2014-15. Studies were eligible if they were original studies published in a peer-reviewed journal; recruited children (aged 0-18 years at diagnosis) with cancer or their parents, or adult patients with cancer; and assessed psychosocial outcomes, including quality of life, depression, anxiety, wellbeing, distress, coping, or adjustment as a primary or secondary outcome. We assessed participation reporting quality, calculated percentages of participation achieved, and measured the influence of study design and participant characteristics. We reviewed 311 studies including a total of 87 240 adults, children, and parents. Mean participation across studies was more than 70% (paediatric participation was 72% and adult participation was 74%). Many studies did not report data essential for the assessment of participation, especially for non-respondents. Studies using a longitudinal cohort design had higher participation than randomised trials. In paediatric studies, recruitment of participants at diagnosis, face to face, and with the use of short questionnaires yielded higher participation. Other study design characteristics (method of data collection, who enrolled the participants, and incentives) and patient characteristics (cancer type, patient or parent age, and sex) did not affect participation in either paediatric or adult studies. Researchers can use these data to improve reporting quality and make evidence-based choices to maximise participation in future studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

A semi-empirical model relating micro structure to acoustic properties of bimodal porous material

NASA Astrophysics Data System (ADS)

Mosanenzadeh, Shahrzad Ghaffari; Doutres, Olivier; Naguib, Hani E.; Park, Chul B.; Atalla, Noureddine

2015-01-01

Complex morphology of open cell porous media makes it difficult to link microstructural parameters and acoustic behavior of these materials. While morphology determines the overall sound absorption and noise damping effectiveness of a porous structure, little is known on the influence of microstructural configuration on the macroscopic properties. In the present research, a novel bimodal porous structure was designed and developed solely for modeling purposes. For the developed porous structure, it is possible to have direct control on morphological parameters and avoid complications raised by intricate pore geometries. A semi-empirical model is developed to relate microstructural parameters to macroscopic characteristics of porous material using precise characterization results based on the designed bimodal porous structures. This model specifically links macroscopic parameters including static airflow resistivity ( σ ) , thermal characteristic length ( Λ ' ) , viscous characteristic length ( Λ ) , and dynamic tortuosity ( α ∞ ) to microstructural factors such as cell wall thickness ( 2 t ) and reticulation rate ( R w ) . The developed model makes it possible to design the morphology of porous media to achieve optimum sound absorption performance based on the application in hand. This study makes the base for understanding the role of microstructural geometry and morphological factors on the overall macroscopic parameters of porous materials specifically for acoustic capabilities. The next step is to include other microstructural parameters as well to generalize the developed model. In the present paper, pore size was kept constant for eight categories of bimodal foams to study the effect of secondary porous structure on macroscopic properties and overall acoustic behavior of porous media.

MASCOT - MATLAB Stability and Control Toolbox

NASA Technical Reports Server (NTRS)

Kenny, Sean; Crespo, Luis

2011-01-01

MASCOT software was created to provide the conceptual aircraft designer accurate predictions of air vehicle stability and control characteristics. The code takes as input mass property data in the form of an inertia tensor, aerodynamic loading data, and propulsion (i.e. thrust) loading data. Using fundamental non-linear equations of motion, MASCOT then calculates vehicle trim and static stability data for any desired flight condition. Common predefined flight conditions are included. The predefined flight conditions include six horizontal and six landing rotation conditions with varying options for engine out, crosswind and sideslip, plus three takeoff rotation conditions. Results are displayed through a unique graphical interface developed to provide stability and control information to the conceptual design engineers using a qualitative scale indicating whether the vehicle has acceptable, marginal, or unacceptable static stability characteristics. This software allows the user to prescribe the vehicle s CG location, mass, and inertia tensor so that any loading configuration between empty weight and maximum take-off weight can be analyzed. The required geometric and aerodynamic data as well as mass and inertia properties may be entered directly, passed through data files, or come from external programs such as Vehicle Sketch Pad (VSP). The current version of MASCOT has been tested with VSP used to compute the required data, which is then passed directly into the program. In VSP, the vehicle geometry is created and manipulated. The aerodynamic coefficients, stability and control derivatives, are calculated using VorLax, which is now available directly within VSP. MASCOT has been written exclusively using the technical computing language MATLAB . This innovation is able to bridge the gap between low-fidelity conceptual design and higher-fidelity stability and control analysis. This new tool enables the conceptual design engineer to include detailed static stability and trim constraints in the conceptual design loop. The unique graphical interface developed for this tool presents the stability data in a format that is understandable by the conceptual designer, yet also provides the detailed quantitative results if desired.

The Project TALENT Twin and Sibling Study.

PubMed

Prescott, Carol A; Achorn, Deanna Lyter; Kaiser, Ashley; Mitchell, Lindsey; McArdle, John J; Lapham, Susan J

2013-02-01

Project TALENT is a US national longitudinal study of about 377,000 individuals born in 1942-1946, first assessed in 1960. Students in about 1,200 schools participated in a 2-day battery covering aptitudes, abilities, interests, and individual and family characteristics (Flanagan, 1962; www.projectTALENT.org). Follow-up assessments 1, 5, and 11 years later assessed educational and occupational outcomes. The sample includes approximately 92,000 siblings from 40,000 families, including 2,500 twin pairs and 1,200 other siblings of twins. Until recently, almost no behavior genetic research has been conducted with the sample. In the original data collection information was not collected with the intent to link family members. Recently, we developed algorithms using names, addresses, birthdates, and information about family structure to link siblings and identify twins. We are testing several methods to determine zygosity, including use of yearbook photographs. In this paper, we summarize the design and measures in Project TALENT, describe the Twin and Sibling sample, and present our twin-sib-classmate model. In most twin and family designs, the 'shared environment' includes factors specific to the family combined with between-family differences associated with macro-level variables such as socioeconomic status. The school-based sampling design used in Project TALENT provides a unique opportunity to partition the shared environment into variation shared by siblings, specific to twins, and associated with school- and community-level factors. The availability of many measured characteristics on the family, schools, and neighborhoods enhances the ability to study the impact of specific factors on behavioral variation.

Exploring Mechanisms for Effective Technology-Enhanced Simulation-based Education in Wilderness Medicine: A Systematic Review

PubMed Central

MacKinnon, Ralph; Humphries, Christopher

2015-01-01

Background: Technology-enhanced simulation is well-established in healthcare teaching curricula, including those regarding wilderness medicine. Compellingly, the evidence base for the value of this educational modality to improve learner competencies and patient outcomes are increasing. Aims: The aim was to systematically review the characteristics of technology-enhanced simulation presented in the wilderness medicine literature to date. Then, the secondary aim was to explore how this technology has been used and if the use of this technology has been associated with improved learner or patient outcomes. Methods: EMBASE and MEDLINE were systematically searched from 1946 to 2014, for articles on the provision of technology-enhanced simulation to teach wilderness medicine. Working independently, the team evaluated the information on the criteria of learners, setting, instructional design, content, and outcomes. Results: From a pool of 37 articles, 11 publications were eligible for systematic review. The majority of learners in the included publications were medical students, settings included both indoors and outdoors, and the main focus clinical content was initial trauma management with some including leadership skills. The most prevalent instructional design components were clinical variation and cognitive interactivity, with learner satisfaction as the main outcome. Conclusions: The results confirm that the current provision of wilderness medicine utilizing technology-enhanced simulation is aligned with instructional design characteristics that have been used to achieve effective learning. Future research should aim to demonstrate the translation of learning into the clinical field to produce improved learner outcomes and create improved patient outcomes. PMID:26824012

Design and Analysis of Tubular Permanent Magnet Linear Wave Generator

PubMed Central

Si, Jikai; Feng, Haichao; Su, Peng; Zhang, Lufeng

2014-01-01

Due to the lack of mature design program for the tubular permanent magnet linear wave generator (TPMLWG) and poor sinusoidal characteristics of the air gap flux density for the traditional surface-mounted TPMLWG, a design method and a new secondary structure of TPMLWG are proposed. An equivalent mathematical model of TPMLWG is established to adopt the transformation relationship between the linear velocity of permanent magnet rotary generator and the operating speed of TPMLWG, to determine the structure parameters of the TPMLWG. The new secondary structure of the TPMLWG contains surface-mounted permanent magnets and the interior permanent magnets, which form a series-parallel hybrid magnetic circuit, and their reasonable structure parameters are designed to get the optimum pole-arc coefficient. The electromagnetic field and temperature field of TPMLWG are analyzed using finite element method. It can be included that the sinusoidal characteristics of air gap flux density of the new secondary structure TPMLWG are improved, the cogging force as well as mechanical vibration is reduced in the process of operation, and the stable temperature rise of generator meets the design requirements when adopting the new secondary structure of the TPMLWG. PMID:25050388

On an efficient multilevel inverter assembly: structural savings and design optimisations

NASA Astrophysics Data System (ADS)

Choupan, Reza; Nazarpour, Daryoush; Golshannavaz, Sajjad

2018-01-01

This study puts forward an efficient unit cell to be taken in use in multilevel inverter assemblies. The proposed structure is in line with reductions in number of direct current (dc) voltage sources, insulated-gate bipolar transistors (IGBTs), gate driver circuits, installation area, and hence the implementation costs. Such structural savings do not sacrifice the technical performance of the proposed design wherein an increased number of output voltage levels is attained, interestingly. Targeting a techno-economic characteristic, the contemplated structure is included as the key unit of cascaded multilevel inverters. Such extensions require development of applicable design procedures. To this end, two efficient strategies are elaborated to determine the magnitudes of input dc voltage sources. As well, an optimisation process is developed to explore the optimal allocation of different parameters in overall performance of the proposed inverter. These parameters are investigated as the number of IGBTs, dc sources, diodes, and overall blocked voltage on switches. In the lights of these characteristics, a comprehensive analysis is established to compare the proposed design with the conventional and recently developed structures. Detailed simulation and experimental studies are conducted to assess the performance of the proposed design. The obtained results are discussed in depth.

Design and analysis of tubular permanent magnet linear wave generator.

PubMed

Si, Jikai; Feng, Haichao; Su, Peng; Zhang, Lufeng

2014-01-01

Due to the lack of mature design program for the tubular permanent magnet linear wave generator (TPMLWG) and poor sinusoidal characteristics of the air gap flux density for the traditional surface-mounted TPMLWG, a design method and a new secondary structure of TPMLWG are proposed. An equivalent mathematical model of TPMLWG is established to adopt the transformation relationship between the linear velocity of permanent magnet rotary generator and the operating speed of TPMLWG, to determine the structure parameters of the TPMLWG. The new secondary structure of the TPMLWG contains surface-mounted permanent magnets and the interior permanent magnets, which form a series-parallel hybrid magnetic circuit, and their reasonable structure parameters are designed to get the optimum pole-arc coefficient. The electromagnetic field and temperature field of TPMLWG are analyzed using finite element method. It can be included that the sinusoidal characteristics of air gap flux density of the new secondary structure TPMLWG are improved, the cogging force as well as mechanical vibration is reduced in the process of operation, and the stable temperature rise of generator meets the design requirements when adopting the new secondary structure of the TPMLWG.

Research on dynamic characteristics of motor vibration isolation system through mechanical impedance method

NASA Astrophysics Data System (ADS)

Zhao, Xingqian; Xu, Wei; Shuai, Changgeng; Hu, Zechao

2017-12-01

A mechanical impedance model of a coupled motor-shaft-bearing system has been developed to predict the dynamic characteristics and partially validated by comparing the computing results with finite element method (FEM), including the comparison of displacement amplitude in x and z directions at the two ends of the flexible coupling, the comparison of normalized vertical reaction force in z direction at bearing pedestals. The results demonstrate that the developed model can precisely predict the dynamic characteristics and the main advantage of such a method is that it can clearly illustrate the vibration property of the motor subsystem, which plays an important role in the isolation system design.

A Qualitative Piloted Evaluation of the Tupolev Tu-144 Supersonic Transport

NASA Technical Reports Server (NTRS)

Rivers, Robert A.; Jackson, E. Bruce; Fullerton, C. Gordon; Cox, Timothy H.; Princen, Norman H.

2000-01-01

Two U.S. research pilots evaluated the Tupolev Tu-144 supersonic transport aircraft on three dedicated flights: one subsonic and two supersonic profiles. The flight profiles and maneuvers were developed jointly by Tupolev and U.S. engineers. The vehicle was found to have unique operational and flight characteristics that serve as lessons for designers of future supersonic transport aircraft. Vehicle subsystems and observed characteristics are described as are flight test planning and ground monitoring facilities. Maneuver descriptions and extended pilot narratives for each flight are included as appendices.

Land mobile satellite propagation measurements in Japan using ETS-V satellite

NASA Technical Reports Server (NTRS)

Obara, Noriaki; Tanaka, Kenji; Yamamoto, Shin-Ichi; Wakana, Hiromitsu

1993-01-01

Propagation characteristics of land mobile satellite communications channels have been investigated actively in recent years. Information of propagation characteristics associated with multipath fading and shadowing is required to design commercial land mobile satellite communications systems, including protocol and error correction method. CRL (Communications Research Laboratory) has carried out propagation measurements using the Engineering Test Satellite-V (ETS-V) at L band (1.5 GHz) through main roads in Japan by a medium gain antenna with an autotracking capability. This paper presents the propagation statistics obtained in this campaign.

Spacecraft rendezvous operational considerations affecting vehicle systems design and configuration

NASA Astrophysics Data System (ADS)

Prust, Ellen E.

One lesson learned from Orbiting Maneuvering Vehicle (OMV) program experience is that Design Reference Missions must include an appropriate balance of operations and performance inputs to effectively drive vehicle systems design and configuration. Rendezvous trajectory design is based on vehicle characteristics (e.g., mass, propellant tank size, and mission duration capability) and operational requirements, which have evolved through the Gemini, Apollo, and STS programs. Operational constraints affecting the rendezvous final approach are summarized. The two major objectives of operational rendezvous design are vehicle/crew safety and mission success. Operational requirements on the final approach which support these objectives include: tracking/targeting/communications; trajectory dispersion and navigation uncertainty handling; contingency protection; favorable sunlight conditions; acceptable relative state for proximity operations handover; and compliance with target vehicle constraints. A discussion of the ways each of these requirements may constrain the rendezvous trajectory follows. Although the constraints discussed apply to all rendezvous, the trajectory presented in 'Cargo Transfer Vehicle Preliminary Reference Definition' (MSFC, May 1991) was used as the basis for the comments below.

47 CFR 2.201 - Emission, modulation, and transmission characteristics.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., and transmission characteristics. The following system of designating emission, modulation, and transmission characteristics shall be employed. (a) Emissions are designated according to their classification... characteristics. 2.201 Section 2.201 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY...

47 CFR 2.201 - Emission, modulation, and transmission characteristics.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., and transmission characteristics. The following system of designating emission, modulation, and transmission characteristics shall be employed. (a) Emissions are designated according to their classification... characteristics. 2.201 Section 2.201 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL FREQUENCY...

Suicidal behaviour on subway systems: a review of the epidemiology.

PubMed

Ratnayake, Ruwan; Links, Paul S; Eynan, Rahel

2007-11-01

Suicide on subway systems is a public health challenge that has been reported in urban centers worldwide. Our objective was to analyze studies of suicide on subway systems, develop a profile of characteristics that are suggestive of association with suicides or attempts, and show how this profile can inform prevention. A literature review involving epidemiology studies and studies relating to subway suicide was conducted. Twenty-eight studies were included in this review. Across studies, characteristics were not often assessed for risk factor status, although several characteristics were remarkably similar. Those attempting suicide on the subway appear to be affected by serious mental illness and have contact with mental health services before the suicidal behavior. Several characteristics may be shared among this population, emphasizing the potential for prevention in clinical and public health domains. Well-designed studies that utilize robust data collection and statistical methods are needed to establish the risk status associated with these characteristics.

[Theories and methodologies of engineering designs on sustainable agricultural land consolidation project--a case study of Xuemeiyang land consolidation project in Changtai County, Fujian Province].

PubMed

Ye, Yanmei; Wu, Cifang; Cheng, Chengbiao; Qiu, Lingzhang; Huang, Shengyu; Zheng, Ruihui

2002-09-01

The concept and characteristics of engineering designs on sustainable agricultural land consolidation project were discussed in this paper. Principles, basic methods and procedures of engineering designs on agricultural land consolidation project were put forward, which were successfully adopted for designing agricultural land consolidation in Xuemeiyang region of Changtai County, including diversity designs of sustainable land use, engineering designs of soil improvement, roads, ditches, and drains for protecting existent animal environments, and design of ecological shelter-forests in farmland. Moreover, from sustainable economic, ecological and social points, the results of these engineering designs were evaluated based on fouteen important indexes. After carrying out these engineeringdesigns, the eco-environments and agricultural production conditions were significantly improved, and the farm income was increased in planned regions.

Directory of aerospace safety specialized information sources, volume 2

NASA Technical Reports Server (NTRS)

Rubinstein, R. I.; Pinto, J. J.; Meschkow, S. Z.

1976-01-01

A handbook of organizations and experts in specific and well-defined areas of safety technology is presented. It is designed for the safety specialist as an aid for locating both information sources and individual points of contact (experts) in engineering related fields. The file covers sources of data in aerospace design, tests, and operations, as well as information on hazard and failure cause identification, accident analysis, and materials characteristics. Other related areas include the handling and transportation of hazardous chemicals, radioactive isotopes, and liquified natural gases.

[Design and development of the DSA digital subtraction workstation].

PubMed

Peng, Wen-Xian; Peng, Tian-Zhou; Xia, Shun-Ren; Jin, Guang-Bo

2008-05-01

According to the patient examination criterion and the demands of all related departments, the DSA digital subtraction workstation has been successfully designed and is introduced in this paper by analyzing the characteristic of video source of DSA which was manufactured by GE Company and has no DICOM standard interface. The workstation includes images-capturing gateway and post-processing software. With the developed workstation, all images from this early DSA equipment are transformed into DICOM format and then are shared in different machines.

Hypersonic airbreathing vehicle visions and enhancing technologies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hunt, J.L.; Lockwood, M.K.; Petley, D.H.

1997-01-01

This paper addresses the visions for hypersonic airbreathing vehicles and the advanced technologies that forge and enhance the designs. The matrix includes space access vehicles (single-stage-to-orbit (SSTO), two-stage-to-orbit (2STO) and three-stage-to-orbit (3STO)) and endoatmospheric vehicles (airplanes{emdash}missiles are omitted). The characteristics, the performance potential, the technologies and the synergies will be discussed. A common design constraint is that all vehicles (space access and endoatmospheric) have enclosed payload bays. {copyright} {ital 1997 American Institute of Physics.}

Ice interaction with offshore structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cammaert, A.B.; Muggeridge, D.B.

1988-01-01

Oil platforms and other offshore structures being built in the arctic regions must be able to withstand icebergs, ice islands, and pack ice. This reference explain the effect ice has on offshore structures and demonstrates design and construction methods that allow such structures to survive in harsh, ice-ridden environments. It analyzes the characteristics of sea ice as well as dynamic ice forces on structures. Techniques for ice modeling and field testing facilitate the design and construction of sturdy, offshore constructions. Computer programs included.

On-board processing architectures for satellite B-ISDN services

NASA Technical Reports Server (NTRS)

Inukai, Thomas; Shyy, Dong-Jye; Faris, Faris

1991-01-01

Onboard baseband processing architectures for future satellite broadband integrated services digital networks (B-ISDN's) are addressed. To assess the feasibility of implementing satellite B-ISDN services, critical design issues, such as B-ISDN traffic characteristics, transmission link design, and a trade-off between onboard circuit and fast packet switching, are analyzed. Examples of the two types of switching mechanisms and potential onboard network control functions are presented. A sample network architecture is also included to illustrate a potential onboard processing system.

On-board processing satellite network architectures for broadband ISDN

NASA Technical Reports Server (NTRS)

Inukai, Thomas; Faris, Faris; Shyy, Dong-Jye

1992-01-01

Onboard baseband processing architectures for future satellite broadband integrated services digital networks (B-ISDN's) are addressed. To assess the feasibility of implementing satellite B-ISDN services, critical design issues, such as B-ISDN traffic characteristics, transmission link design, and a trade-off between onboard circuit and fast packet switching, are analyzed. Examples of the two types of switching mechanisms and potential onboard network control functions are presented. A sample network architecture is also included to illustrate a potential onboard processing system.

Floating point arithmetic in future supercomputers

NASA Technical Reports Server (NTRS)

Bailey, David H.; Barton, John T.; Simon, Horst D.; Fouts, Martin J.

1989-01-01

Considerations in the floating-point design of a supercomputer are discussed. Particular attention is given to word size, hardware support for extended precision, format, and accuracy characteristics. These issues are discussed from the perspective of the Numerical Aerodynamic Simulation Systems Division at NASA Ames. The features believed to be most important for a future supercomputer floating-point design include: (1) a 64-bit IEEE floating-point format with 11 exponent bits, 52 mantissa bits, and one sign bit and (2) hardware support for reasonably fast double-precision arithmetic.

Automated Space Processing Payloads Study. Volume 1: Executive Summary

NASA Technical Reports Server (NTRS)

1975-01-01

An investigation is described which examined the extent to which the experiment hardware and operational requirements can be met by automatic control and material handling devices; payload and system concepts are defined which make extensive use of automation technology. Topics covered include experiment requirements and hardware data, capabilities and characteristics of industrial automation equipment and controls, payload grouping, automated payload conceptual design, space processing payload preliminary design, automated space processing payloads for early shuttle missions, and cost and scheduling.

Wide sector coverage antennas

NASA Astrophysics Data System (ADS)

Yaw, D. F.

1984-09-01

The general design and performance characteristics of transmit and receive antennas that are currently used in electronic warfare systems are reviewed. Among transmit antennas, three-to-one bandwidth, asymmetric-beam, and circularly polarized horns are discussed, as are extremely broadband monopoles and spiral antennas. In a discussion of receive antennas, attention is given to flat and conical spirals, including cavity-backed flat spirals operating over the 2.5-18 GHz range; log periodic dipoles; and biconical horns. Finally, the design configurations and performance of interferometer direction-finding systems are briefly discussed.

MODEL BASED BIOMASS SYSTEM DESIGN OF FEEDSTOCK SUPPLY SYSTEMS FOR BIOENERGY PRODUCTION

DOE Office of Scientific and Technical Information (OSTI.GOV)

David J. Muth, Jr.; Jacob J. Jacobson; Kenneth M. Bryden

Engineering feedstock supply systems that deliver affordable, high-quality biomass remains a challenge for the emerging bioenergy industry. Cellulosic biomass is geographically distributed and has diverse physical and chemical properties. Because of this feedstock supply systems that deliver cellulosic biomass resources to biorefineries require integration of a broad set of engineered unit operations. These unit operations include harvest and collection, storage, preprocessing, and transportation processes. Design decisions for each feedstock supply system unit operation impact the engineering design and performance of the other system elements. These interdependencies are further complicated by spatial and temporal variances such as climate conditions and biomassmore » characteristics. This paper develops an integrated model that couples a SQL-based data management engine and systems dynamics models to design and evaluate biomass feedstock supply systems. The integrated model, called the Biomass Logistics Model (BLM), includes a suite of databases that provide 1) engineering performance data for hundreds of equipment systems, 2) spatially explicit labor cost datasets, and 3) local tax and regulation data. The BLM analytic engine is built in the systems dynamics software package PowersimTM. The BLM is designed to work with thermochemical and biochemical based biofuel conversion platforms and accommodates a range of cellulosic biomass types (i.e., herbaceous residues, short- rotation woody and herbaceous energy crops, woody residues, algae, etc.). The BLM simulates the flow of biomass through the entire supply chain, tracking changes in feedstock characteristics (i.e., moisture content, dry matter, ash content, and dry bulk density) as influenced by the various operations in the supply chain. By accounting for all of the equipment that comes into contact with biomass from the point of harvest to the throat of the conversion facility and the change in characteristics, the BLM evaluates economic performance of the engineered system, as well as determining energy consumption and green house gas performance of the design. This paper presents a BLM case study delivering corn stover to produce cellulosic ethanol. The case study utilizes the BLM to model the performance of several feedstock supply system designs. The case study also explores the impact of temporal variations in climate conditions to test the sensitivity of the engineering designs. Results from the case study show that under certain conditions corn stover can be delivered to the cellulosic ethanol biorefinery for $35/dry ton.« less

Force testing manual for the Langley 20-inch Mach 6 tunnel

NASA Technical Reports Server (NTRS)

Keyes, J. W.

1977-01-01

Data reduction and procedures for conducting force tests in a 20 inch Mach 6 tunnel are described. A discussion of pretest and testing phases are included. Items that are to be checked during model design and construction are outlined as well as safety requirements, starting loads tests, instructions for data acquisition and model installation. Measurement of balance and model misalignment and instructions for calibrating the angle of attack screen are covered. Procedures for making reference pressure, attitude tare, and data runs are included. The 20 inch tunnel force program is examined, and a description of data recording system input and load contrast sheets is given. An appendix presents a description, operating characteristics, and Mach number calibration of the tunnel, as well as tunnel characteristics.

The MSFC complementary metal oxide semiconductor (including multilevel interconnect metallization) process handbook

NASA Technical Reports Server (NTRS)

Bouldin, D. L.; Eastes, R. W.; Feltner, W. R.; Hollis, B. R.; Routh, D. E.

1979-01-01

The fabrication techniques for creation of complementary metal oxide semiconductor integrated circuits at George C. Marshall Space Flight Center are described. Examples of C-MOS integrated circuits manufactured at MSFC are presented with functional descriptions of each. Typical electrical characteristics of both p-channel metal oxide semiconductor and n-channel metal oxide semiconductor discrete devices under given conditions are provided. Procedures design, mask making, packaging, and testing are included.

A vacuum four-ball tribometer to evaluate liquid lubricants for space applications

NASA Technical Reports Server (NTRS)

Masuko, Masabumi; Jones, William R., Jr.; Jansen, Ralph; Ebihara, Ben; Pepper, Stephen V.; Helmick, Larry S.

1993-01-01

The design and operation of a vacuum tribometer, based on the four-ball configuration, is described. This tribometer evaluates the tribological characteristics of liquid lubricants for space applications. Operating conditions include: room temperature, loads to approximately 1000N, speeds to approximately 500 rpm, and pressures of approximately 10(exp -6)Pa. Tests can also be run at atmospheric pressure with air or nitrogen. Some typical test results are included.

Real-time handling of existing content sources on a multi-layer display

NASA Astrophysics Data System (ADS)

Singh, Darryl S. K.; Shin, Jung

2013-03-01

A Multi-Layer Display (MLD) consists of two or more imaging planes separated by physical depth where the depth is a key component in creating a glasses-free 3D effect. Its core benefits include being viewable from multiple angles, having full panel resolution for 3D effects with no side effects of nausea or eye-strain. However, typically content must be designed for its optical configuration in foreground and background image pairs. A process was designed to give a consistent 3D effect in a 2-layer MLD from existing stereo video content in real-time. Optimizations to stereo matching algorithms that generate depth maps in real-time were specifically tailored for the optical characteristics and image processing algorithms of a MLD. The end-to-end process included improvements to the Hierarchical Belief Propagation (HBP) stereo matching algorithm, improvements to optical flow and temporal consistency. Imaging algorithms designed for the optical characteristics of a MLD provided some visual compensation for depth map inaccuracies. The result can be demonstrated in a PC environment, displayed on a 22" MLD, used in the casino slot market, with 8mm of panel seperation. Prior to this development, stereo content had not been used to achieve a depth-based 3D effect on a MLD in real-time

Distributed feedback InGaN/GaN laser diodes

NASA Astrophysics Data System (ADS)

Slight, Thomas J.; Watson, Scott; Yadav, Amit; Grzanka, Szymon; Stanczyk, Szymon; Docherty, Kevin E.; Rafailov, Edik; Perlin, Piotr; Najda, Steve; Leszczyński, Mike; Kelly, Anthony E.

2018-02-01

We have realised InGaN/GaN distributed feedback laser diodes emitting at a single wavelength in the 42X nm wavelength range. Laser diodes based on Gallium Nitride (GaN) are useful devices in a wide range of applications including atomic spectroscopy, data storage and optical communications. To fully exploit some of these application areas there is a need for a GaN laser diode with high spectral purity, e.g. in atomic clocks, where a narrow line width blue laser source can be used to target the atomic cooling transition. Previously, GaN DFB lasers have been realised using buried or surface gratings. Buried gratings require complex overgrowth steps which can introduce epi-defects. Surface gratings designs, can compromise the quality of the p-type contact due to dry etch damage and are prone to increased optical losses in the grating regions. In our approach the grating is etched into the sidewall of the ridge. Advantages include a simpler fabrication route and design freedom over the grating coupling strength.Our intended application for these devices is cooling of the Sr+ ion and for this objective the laser characteristics of SMSR, linewidth, and power are critical. We investigate how these characteristics are affected by adjusting laser design parameters such as grating coupling coefficient and cavity length.

Analysis of Feeder Bus Network Design and Scheduling Problems

PubMed Central

Almasi, Mohammad Hadi; Karim, Mohamed Rehan

2014-01-01

A growing concern for public transit is its inability to shift passenger's mode from private to public transport. In order to overcome this problem, a more developed feeder bus network and matched schedules will play important roles. The present paper aims to review some of the studies performed on Feeder Bus Network Design and Scheduling Problem (FNDSP) based on three distinctive parts of the FNDSP setup, namely, problem description, problem characteristics, and solution approaches. The problems consist of different subproblems including data preparation, feeder bus network design, route generation, and feeder bus scheduling. Subsequently, descriptive analysis and classification of previous works are presented to highlight the main characteristics and solution methods. Finally, some of the issues and trends for future research are identified. This paper is targeted at dealing with the FNDSP to exhibit strategic and tactical goals and also contributes to the unification of the field which might be a useful complement to the few existing reviews. PMID:24526890

Assessing college-level learning difficulties and "at riskness" for learning disabilities and ADHD: development and validation of the learning difficulties assessment.

PubMed

Kane, Steven T; Walker, John H; Schmidt, George R

2011-01-01

This article describes the development and validation of the Learning Difficulties Assessment (LDA), a normed and web-based survey that assesses perceived difficulties with reading, writing, spelling, mathematics, listening, concentration, memory, organizational skills, sense of control, and anxiety in college students. The LDA is designed to (a) map individual learning strengths and weaknesses, (b) provide users with a comparative sense of their academic skills, (c) integrate research in user-interface design to assist those with reading and learning challenges, and (d) identify individuals who may be at risk for learning disabilities and attention-deficit/hyperactivity disorder (ADHD) and who should thus be further assessed. Data from a large-scale 5-year study describing the instrument's validity as a screening tool for learning disabilities and ADHD are presented. This article also describes unique characteristics of the LDA including its user-interface design, normative characteristics, and use as a no-cost screening tool for identifying college students at risk for learning disorders and ADHD.

Analysis of flow field characteristics in IC equipment chamber based on orthogonal design

NASA Astrophysics Data System (ADS)

Liu, W. F.; Yang, Y. Y.; Wang, C. N.

2017-01-01

This paper aims to study the influence of the configuration of processing chamber as a part of IC equipment on flow field characteristics. Four parameters, including chamber height, chamber diameter, inlet mass flow rate and outlet area, are arranged using orthogonally design method to study their influence on flow distribution in the processing chamber with the commercial software-Fluent. The velocity, pressure and temperature distribution above the holder were analysed respectively. The velocity difference value of the gas flow above the holder is defined as the evaluation criteria to evaluate the uniformity of the gas flow. The quantitative relationship between key parameters and the uniformity of gas flow was found through analysis of experimental results. According to our study, the chamber height is the most significant factor, and then follows the outlet area, chamber diameter and inlet mass flow rate. This research can provide insights into the study and design of configuration of etcher, plasma enhanced chemical vapor deposition (PECVD) equipment, and other systems with similar configuration and processing condition.

Evaluation of the Shuttle GN&C during powered ascent flight phase. [Guidance Navigation and Control equipment system design and flight tests

NASA Technical Reports Server (NTRS)

Olson, L.; Sunkel, J. W.

1982-01-01

An overview of the ascent trajectory and GN&C (guidance, navigation, and control) system design is followed by a summary of flight test results for the ascent phase of STS-1. The most notable variance from nominal pre-flight predictions was the lofted trajectory observed in first stage due to an unanticipated shift in pitch aerodynamic characteristics from those predicted by wind tunnel tests. The GN&C systems performed as expected on STS-1 throughout powered flight. Following a discussion of the software constants changed for Flight 2 to provide adequate performance margin, a summary of test results from STS-2 and STS-3 is presented. Vehicle trajectory response and GN&C system behavior were very similar to STS-1. Ascent aerodynamic characteristics extracted from the first two test flights were included in the data base used to design the first stage steering and pitch trim profiles for STS-3.

Preliminary noise tradeoff study of a Mach 2.7 cruise aircraft

NASA Technical Reports Server (NTRS)

Mascitti, V. R.; Maglieri, D. J. (Editor); Raney, J. P. (Editor)

1979-01-01

NASA computer codes in the areas of preliminary sizing and enroute performance, takeoff and landing performance, aircraft noise prediction, and economics were used in a preliminary noise tradeoff study for a Mach 2.7 design supersonic cruise concept. Aerodynamic configuration data were based on wind-tunnel model tests and related analyses. Aircraft structural characteristics and weight were based on advanced structural design methodologies, assuming conventional titanium technology. The most advanced noise prediction techniques available were used, and aircraft operating costs were estimated using accepted industry methods. The 4-engines cycles included in the study were based on assumed 1985 technology levels. Propulsion data was provided by aircraft manufacturers. Additional empirical data is needed to define both noise reduction features and other operating characteristics of all engine cycles under study. Data on VCE design parameters, coannular nozzle inverted flow noise reduction and advanced mechanical suppressors are urgently needed to reduce the present uncertainties in studies of this type.

Identification of stem cells from human umbilical cord blood with embryonic and hematopoietic characteristics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao Yong; Wang Honglan; Mazzone, Theodore

2006-08-01

We identified stem cells from the umbilical cord blood, designated cord blood-stem cells (CB-SC). CB-SC displayed important embryonic stem (ES) cell characteristics including expression of ES-cell-specific molecular markers including transcription factors OCT-4 and Nanog, along with stage-specific embryonic antigen (SSEA)-3 and SSEA-4. CB-SC also expressed hematopoietic cell antigens including CD9, CD45 and CD117, but were negative for CD34. CB-SC displayed very low immunogenicity as indicated by expression of a very low level of major histocompatibility complex (MHC) antigens and failure to stimulate the proliferation of allogeneic lymphocytes. CB-SC could give rise to cells with endothelial-like and neuronal-like characteristics in vitro,more » as demonstrated by expression of lineage-associated markers. Notably, CB-SC could be stimulated to differentiate into functional insulin-producing cells in vivo and eliminated hyperglycemia after transplantation into a streptozotocin-induced diabetic mouse model. These findings may have significant potential to advance stem-cell-based therapeutics.« less

Design of a space shuttle structural dynamics model

NASA Technical Reports Server (NTRS)

1972-01-01

A 1/8 scale structural dynamics model of a parallel burn space shuttle has been designed. Basic objectives were to represent the significant low frequency structural dynamic characteristics while keeping the fabrication costs low. The model was derived from the proposed Grumman Design 619 space shuttle. The design includes an orbiter, two solid rocket motors (SRM) and an external tank (ET). The ET consists of a monocoque LO2 tank an interbank skirt with three frames to accept SRM attachment members, an LH2 tank with 10 frames of which 3 provide for orbiter attachment members, and an aft skirt with on frame to provide for aft SRM attachment members. The frames designed for the SRM attachments are fitted with transverse struts to take symmetric loads.

Analysis of the design and performance characteristics of pumpable roof supports

PubMed Central

Timothy, Batchler

2017-01-01

Pumpable roof supports are currently being used to provide a safe working environment for longwall mining. Because different pumpable supports are visually similar and installed fundamentally in the same manner as other supports, there is a tendency to believe they all perform the same way. However, there are several design parameters that can affect their performance, including the cementitious material properties and the bag construction practices that influence the degree of confinement provided. A full understanding of the impact of these design parameters is necessary to optimize the support application and to provide a foundation for making further improvements in the support performance. This paper evaluates the impact of various support design parameters by examining full-scale performance tests conducted using the National Institute for Occupational Safety and Health (NIOSH) Mine Roof Simulator (MRS) as part of manufacturers’ developmental and quality control testing. These tests were analyzed to identify correlations between the support design parameters and the resulting performance. Based on more than 160 tests over 7 years, quantifiable patterns were examined to assess the correlation between the support dimensions, cementitious material type, wire pitch, and single-wall vs. dual-walled bag designs to the support capacity, stiffness, load shedding events, and yield characteristics. PMID:28775910

Challenges of developing a cardiovascular risk calculator for patients with rheumatoid arthritis.

PubMed

Crowson, Cynthia S; Rollefstad, Silvia; Kitas, George D; van Riel, Piet L C M; Gabriel, Sherine E; Semb, Anne Grete

2017-01-01

Cardiovascular disease (CVD) risk calculators designed for use in the general population do not accurately predict the risk of CVD among patients with rheumatoid arthritis (RA), who are at increased risk of CVD. The process of developing risk prediction models involves numerous issues. Our goal was to develop a CVD risk calculator for patients with RA. Thirteen cohorts of patients with RA originating from 10 different countries (UK, Norway, Netherlands, USA, Sweden, Greece, South Africa, Spain, Canada and Mexico) were combined. CVD risk factors and RA characteristics at baseline, in addition to information on CVD outcomes were collected. Cox models were used to develop a CVD risk calculator, considering traditional CVD risk factors and RA characteristics. Model performance was assessed using measures of discrimination and calibration with 10-fold cross-validation. A total of 5638 RA patients without prior CVD were included (mean age: 55 [SD: 14] years, 76% female). During a mean follow-up of 5.8 years (30139 person years), 389 patients developed a CVD event. Event rates varied between cohorts, necessitating inclusion of high and low risk strata in the models. The multivariable analyses revealed 2 risk prediction models including either a disease activity score including a 28 joint count and erythrocyte sedimentation rate (DAS28ESR) or a health assessment questionnaire (HAQ) along with age, sex, presence of hypertension, current smoking and ratio of total cholesterol to high-density lipoprotein cholesterol. Unfortunately, performance of these models was similar to general population CVD risk calculators. Efforts to develop a specific CVD risk calculator for patients with RA yielded 2 potential models including RA disease characteristics, but neither demonstrated improved performance compared to risk calculators designed for use in the general population. Challenges encountered and lessons learned are discussed in detail.

Precipitation areal-reduction factor estimation using an annual-maxima centered approach

USGS Publications Warehouse

Asquith, W.H.; Famiglietti, J.S.

2000-01-01

The adjustment of precipitation depth of a point storm to an effective (mean) depth over a watershed is important for characterizing rainfall-runoff relations and for cost-effective designs of hydraulic structures when design storms are considered. A design storm is the precipitation point depth having a specified duration and frequency (recurrence interval). Effective depths are often computed by multiplying point depths by areal-reduction factors (ARF). ARF range from 0 to 1, vary according to storm characteristics, such as recurrence interval; and are a function of watershed characteristics, such as watershed size, shape, and geographic location. This paper presents a new approach for estimating ARF and includes applications for the 1-day design storm in Austin, Dallas, and Houston, Texas. The approach, termed 'annual-maxima centered,' specifically considers the distribution of concurrent precipitation surrounding an annual-precipitation maxima, which is a feature not seen in other approaches. The approach does not require the prior spatial averaging of precipitation, explicit determination of spatial correlation coefficients, nor explicit definition of a representative area of a particular storm in the analysis. The annual-maxima centered approach was designed to exploit the wide availability of dense precipitation gauge data in many regions of the world. The approach produces ARF that decrease more rapidly than those from TP-29. Furthermore, the ARF from the approach decay rapidly with increasing recurrence interval of the annual-precipitation maxima. (C) 2000 Elsevier Science B.V.The adjustment of precipitation depth of a point storm to an effective (mean) depth over a watershed is important for characterizing rainfall-runoff relations and for cost-effective designs of hydraulic structures when design storms are considered. A design storm is the precipitation point depth having a specified duration and frequency (recurrence interval). Effective depths are often computed by multiplying point depths by areal-reduction factors (ARF). ARF range from 0 to 1, vary according to storm characteristics, such as recurrence interval; and are a function of watershed characteristics, such as watershed size, shape, and geographic location. This paper presents a new approach for estimating ARF and includes applications for the 1-day design storm in Austin, Dallas, and Houston, Texas. The approach, termed 'annual-maxima centered,' specifically considers the distribution of concurrent precipitation surrounding an annual-precipitation maxima, which is a feature not seen in other approaches. The approach does not require the prior spatial averaging of precipitation, explicit determination of spatial correlation coefficients, nor explicit definition of a representative area of a particular storm in the analysis. The annual-maxima centered approach was designed to exploit the wide availability of dense precipitation gauge data in many regions of the world. The approach produces ARF that decrease more rapidly than those from TP-29. Furthermore, the ARF from the approach decay rapidly with increasing recurrence interval of the annual-precipitation maxima.

Selection of a surface tension propellant management system for the Viking 75 Orbiter.

NASA Technical Reports Server (NTRS)

Dowdy, M. W.; Debrock, S. C.

1972-01-01

Discussion of the propellant management system requirements derived for the Viking 75 mission, and review of a series of surface tension propellant management system design concepts. The chosen concept is identified and its mission operation described. The ullage bubble and bulk liquid positioning characteristics are presented, along with propellant dynamic considerations entailed by thrust initiation/termination. Pressurization design considerations, required to assure minimum disturbance to the bulk propellant, are introduced as well as those of the tank ullage vent. Design provisions to assure liquid communication between tank ends are discussed. Results of a preliminary design study are presented, including mechanical testing requirements to assure structural integrity, propellant compatibility, and proper installation.

CHAracteristics of research studies that iNfluence practice: a GEneral survey of Canadian orthopaedic Surgeons (CHANGES): a pilot survey.

PubMed

de Sa, Darren; Thornley, Patrick; Evaniew, Nathan; Madden, Kim; Bhandari, Mohit; Ghert, Michelle

2015-01-01

Evidence Based Medicine (EBM) is increasingly being applied to inform clinical decision-making in orthopaedic surgery. Despite the promotion of EBM in Orthopaedic Surgery, the adoption of results from high quality clinical research seems highly unpredictable and does not appear to be driven strictly by randomized trial data. The objective of this study was to pilot a survey to determine if we could identify surgeon opinions on the characteristics of research studies that are perceived as being most likely to influence clinical decision-making among orthopaedic surgeons in Canada. A 28-question electronic survey was distributed to active members of the Canadian Orthopaedic Association (COA) over a period of 11 weeks. The questionnaire sought to analyze the influence of both extrinsic and intrinsic characteristics of research studies and their potential to influence practice patterns. Extrinsic factors included the perceived journal quality and investigator profiles, economic impact, peer/patient/industry influence and individual surgeon residency/fellowship training experiences. Intrinsic factors included study design, sample size, and outcomes reported. Descriptive statistics are provided. Of the 109 members of the COA who opened the survey, 95 (87%) completed the survey in its entirety. The overall response rate was 11% (95/841). Surgeons achieved consensus on the influence of three key designs on their practices: 1) randomized controlled trials 94 (99%), 2) meta-analysis 83 (87%), and 3) systematic reviews 81 (85%). Sixty-seven percent of surgeons agreed that studies with sample sizes of 101-500 or more were more likely to influence clinical practice than smaller studies (n = <100). Factors other than design influencing adoption included 1) reputation of the investigators (99%) and 2) perceived quality of the journal (75%). Although study design and sample size (i.e. minimum of 100 patients) have some influence on clinical decision making, surgeon respondents are equally influenced by investigator reputation and perceived journal quality. At present, continued emphasis on the generation of large, methodologically sound clinical trials remains paramount to translating research findings to clinical practice changes. Specific to this pilot survey, strategies to solicit more widespread responses will be pursued.

A review of characteristics and outcomes of Australia's undergraduate medical education rural immersion programs.

PubMed

O'Sullivan, Belinda G; McGrail, Matthew R; Russell, Deborah; Chambers, Helen; Major, Laura

2018-01-31

A key strategy for increasing the supply of rural doctors is rurally located medical education. In 2000, Australia introduced a national policy to increase rural immersion for undergraduate medical students. This study aims to describe the characteristics and outcomes of the rural immersion programs that were implemented in Australian medical schools. Information about 19 immersion programs was sourced in 2016 via the grey and published literature. A scoping review of the published peer-reviewed studies via Ovid MEDLINE and Informit (2000-2016) and direct journal searching included studies that focused on outcomes of undergraduate rural immersion in Australian medical schools from 2000 to 2016. Programs varied widely by selection criteria and program design, offering between 1- and 6-year immersion. Based on 26 studies from 10 medical schools, rural immersion was positively associated with rural practice in the first postgraduate year (internship) and early career (first 10 years post-qualifying). Having a rural background increased the effects of rural immersion. Evidence suggested that longer duration of immersion also increases the uptake of rural work, including by metropolitan-background students, though overall there was limited evidence about the influence of different program designs. Most evidence was based on relatively weak, predominantly cross-sectional research designs and single-institution studies. Many had flaws including small sample sizes, studying internship outcomes only, inadequately controlling for confounding variables, not using metropolitan-trained controls and providing limited justification as to the postgraduate stage at which rural practice outcomes were measured. Australia's immersion programs are moderately associated with an increased rural supply of early career doctors although metropolitan-trained students contribute equal numbers to overall rural workforce capacity. More research is needed about the influence of student interest in rural practice and the duration and setting of immersion on rural work uptake and working more remotely. Research needs to be more nationally balanced and scaled-up to inform national policy development. Critically, the quality of research could be strengthened through longer-term follow-up studies, adjusting for known confounders, accounting for postgraduate stages and using appropriate controls to test the relative effects of student characteristics and program designs.