1,930 research outputs found
A lightweight, high output soil sampler
Sampler is useful on or under earth's surface or on sea bottom. Larger sample amount is obtained relative to sampler size and weight and limited particle size sample material is continuously delivered. Silicone rubber linear in transport tube nearly eliminates grinding or particulate processing during sampling, and reduces required torque
IMAT graphics manual
The Integrated Multidisciplinary Analysis Tool (IMAT) consists of a menu driven executive system coupled with a relational database which links commercial structures, structural dynamics and control codes. The IMAT graphics system, a key element of the software, provides a common interface for storing, retrieving, and displaying graphical information. The IMAT Graphics Manual shows users of commercial analysis codes (MATRIXx, MSC/NASTRAN and I-DEAS) how to use the IMAT graphics system to obtain high quality graphical output using familiar plotting procedures. The manual explains the key features of the IMAT graphics system, illustrates their use with simple step-by-step examples, and provides a reference for users who wish to take advantage of the flexibility of the software to customize their own applications
A verification procedure for MSC/NASTRAN Finite Element Models
Finite Element Models (FEM's) are used in the design and analysis of aircraft to mathematically describe the airframe structure for such diverse tasks as flutter analysis and actively controlled landing gear design. FEM's are used to model the entire airplane as well as airframe components. The purpose of this document is to describe recommended methods for verifying the quality of the FEM's and to specify a step-by-step procedure for implementing the methods
Field measurements of trace gases and aerosols emitted by peat fires in Central Kalimantan, Indonesia, during the 2015 El Nino
Abstract. Peat fires in Southeast Asia have become a major annual source of trace gases and particles to the regional–global atmosphere. The assessment of their influence on atmospheric chemistry, climate, air quality, and health has been uncertain partly due to a lack of field measurements of the smoke characteristics. During the strong 2015 El Niño event we deployed a mobile smoke sampling team in the Indonesian province of Central Kalimantan on the island of Borneo and made the first, or rare, field measurements of trace gases, aerosol optical properties, and aerosol mass emissions for authentic peat fires burning at various depths in different peat types. This paper reports the trace gas and aerosol measurements obtained by Fourier transform infrared spectroscopy, whole air sampling, photoacoustic extinctiometers (405 and 870 nm), and a small subset of the data from analyses of particulate filters. The trace gas measurements provide emission factors (EFs; grams of a compound per kilogram biomass burned) for up to ∼ 90 gases, including CO2, CO, CH4, non-methane hydrocarbons up to C10, 15 oxygenated organic compounds, NH3, HCN, NOx, OCS, HCl, etc. The modified combustion efficiency (MCE) of the smoke sources ranged from 0.693 to 0.835 with an average of 0.772 ± 0.053 (n = 35), indicating essentially pure smoldering combustion, and the emissions were not initially strongly lofted. The major trace gas emissions by mass (EF as g kg−1) were carbon dioxide (1564 ± 77), carbon monoxide (291 ± 49), methane (9.51 ± 4.74), hydrogen cyanide (5.75 ± 1.60), acetic acid (3.89 ± 1.65), ammonia (2.86 ± 1.00), methanol (2.14 ± 1.22), ethane (1.52 ± 0.66), dihydrogen (1.22 ± 1.01), propylene (1.07 ± 0.53), propane (0.989 ± 0.644), ethylene (0.961 ± 0.528), benzene (0.954 ± 0.394), formaldehyde (0.867 ± 0.479), hydroxyacetone (0.860 ± 0.433), furan (0.772 ± 0.035), acetaldehyde (0.697 ± 0.460), and acetone (0.691 ± 0.356). These field data support significant revision of the EFs for CO2 (−8 %), CH4 (−55 %), NH3 (−86 %), CO (+39 %), and other gases compared with widely used recommendations for tropical peat fires based on a lab study of a single sample published in 2003. BTEX compounds (benzene, toluene, ethylbenzene, xylenes) are important air toxics and aerosol precursors and were emitted in total at 1.5 ± 0.6 g kg−1. Formaldehyde is probably the air toxic gas most likely to cause local exposures that exceed recommended levels. The field results from Kalimantan were in reasonable agreement with recent lab measurements of smoldering Kalimantan peat for “overlap species,” lending importance to the lab finding that burning peat produces large emissions of acetamide, acrolein, methylglyoxal, etc., which were not measurable in the field with the deployed equipment and implying value in continued similar efforts. The aerosol optical data measured include EFs for the scattering and absorption coefficients (EF Bscat and EF Babs, m2 kg−1 fuel burned) and the single scattering albedo (SSA) at 870 and 405 nm, as well as the absorption Ångström exponents (AAE). By coupling the absorption and co-located trace gas and filter data we estimated black carbon (BC) EFs (g kg−1) and the mass absorption coefficient (MAC, m2 g−1) for the bulk organic carbon (OC) due to brown carbon (BrC). Consistent with the minimal flaming, the emissions of BC were negligible (0.0055 ± 0.0016 g kg−1). Aerosol absorption at 405 nm was ∼ 52 times larger than at 870 nm and BrC contributed ∼ 96 % of the absorption at 405 nm. Average AAE was 4.97 ± 0.65 (range, 4.29–6.23). The average SSA at 405 nm (0.974 ± 0.016) was marginally lower than the average SSA at 870 nm (0.998 ± 0.001). These data facilitate modeling climate-relevant aerosol optical properties across much of the UV/visible spectrum and the high AAE and lower SSA at 405 nm demonstrate the dominance of absorption by the organic aerosol. Comparing the Babs at 405 nm to the simultaneously measured OC mass on filters suggests a low MAC ( ∼ 0.1) for the bulk OC, as expected for the low BC/OC ratio in the aerosol. The importance of pyrolysis (at lower MCE), as opposed to glowing (at higher MCE), in producing BrC is seen in the increase of AAE with lower MCE (r2 = 0.65)
COVARIANCE ANALYSIS WITH A COVARIATE INTERACTION: AN EXAMPLE OF A SIMPLE LINEAR REGRESSION COMPARISON TECHNIQUE
Many real data sets that would normally lend themselves to being analyzed by an analysis of covariance, have a covariate interaction present with one or more of the factors in the experiment. Because this violates the assumption of same-slope covariate effect across all treatments, an analysis of covariance should not be performed. The course normally taken when there is such an interaction is to derive regression equations for the dependent variable as a function of the covariate, at each level of the factor(s) being tested. A general linear model F-test can then be used to test whether there are any overall differences between the regression lines. A technique that uses two mathematical distance measures to detect regression line differences once a significant general linear model F-test is obtained is illustrated. Applying these distance measures enables us to perform modified multiple comparisons of the regressions without resorting to the use of multiple pairwise general linear model F-tests, which inflate the Type I error rate. with this method, we are able to incorporate both factor and covariate information into the analysis to overcome the covariate-factor interaction problem
Study of high-speed angular-contact ball bearings under dynamic load
Research program studies behavior of specific high-speed, angular-contact ball bearings. Program is aimed at detailed investigation of ball-separator behavior and lubrication surface-finish effects in a specific gyro wheel
Relationship between newspaper credibility and reader attitude toward Korea and Koreans
As receivers of information from the media, we are faced with the constant problem of determining what sources are and are not credible. Given that much of what we know of the world around us comes directly from the media (Lippman, 1922), as receivers of messages from the media we realise how important the credibility of a news source is. Many of the attitudes that we form about a wide range of issues in society are formed as a direct result of the coverage we receive through the media, although there are numerous other factors involved such as issue involvement, intensity and closure (e.g., Guttman, 1954). Traditionally a large number of studies have argued that a high credibility source is more effective in causing attitude change than a low credibility source (Hovland & Weiss, 1951; Kelman & Hovland, 1953; Bochner & Insko, 1966; McGuire, 1973), while other experimental research examining the interaction between source credibility and other variables have indicated that there are other factors which have an important mediating effect on the impact of source credibility. To further complicate the issue, researchers have argued that credibility is not a stable attribute that a person assigns consistently to a source. Instead, credibility is highly situational and is a changeable perception by a receiver (Berlo, Lemert, & Mertz, 1969; Smith, 1970; Hayes, 1971; Chaffe, 1982). Also, individual differences of receivers such as age, education, gender, and knowledge about the media and the topic could contribute to the evaluation of source credibility (Westley & Serverin, 1964; Lewis, 1981). In addition, the importance of the issue in the media, the controversiality of the issue, receiver bias, the receiver's involvement with the issue and so on have also been shown to have a relationship with the evaluation of source credibility (Stone & Bell, 1975; Robert & Leifer, 1975; Gunther & Lasorsa, 1986). This thesis thus explores the various complexities involved in the relationship between media credibility and attitude formation by examining the characteristics that play a role in making a news source credible to readers, and then considering those factors that affect attitude change in the receivers of a news message. To achieve this, university students in south-east Queensland were examined in order to investigate attitude change regarding the issue of South Korea as a result of coverage in sources they perceive to be of high and low credibility. The study consisted of three stages: a survey of the university students to determine which newspapers they find to be of high and low credibility, a content analysis of their high and low credibility sources for articles of positive, neutral and negative tone, and finally an experiment which measured subjects' attitude change through reading articles of different tones in high and low credibility sources
Beverage Sales and Drinking and Driving: The Role of On-Premise Drinking Places
Objective: The relationships between on-premise drinking places, beverage specific alcohol sales and drinking and driving were examined in a time series cross-sectional study of place-of-last-drink data from Perth, Western Australia. Method: At arrest, 2,411 drinking drivers reported their last location of consumption. Tabulated by 57 premises over 4 years, the rates at which individual premises were referenced as the place-of-last-drink were taken to reflect the relative distributions of numbers of drinking drivers coming from different premise types (hotels, taverns and nightclubs. The data were then statistically related to measures of premise types and characteristics and beverage specific alcohol sales. Results: Significant cross-sectional relationships were obtained between measures of premise types, alcohol sales and drinking and driving. Greatest numbers of drinking drivers came from taverns and from places selling greater amounts of beer and spirits. Significant longitudinal effects were obtained for sales of beer, proportions of high alcohol beer sold and sales of spirits. Conclusions: As a whole, the results suggest that, at least for Western Australia, outlets selling greater amounts of beer and spirits, and greater amounts of high alcohol beer, will produce larger numbers of drinking drivers. (J Stud. Alcohol 60: 47-53, 1999
Can training bar staff in responsible serving practices reduce alcohol-related harm?
A responsible service training programme aimed at reducing alcohol-related harm was implemented in a popular entertainment area over several months in 1992-93. Another popular entertainment area provided a control site. A number of evaluation measures were used: breath tests on 872 patrons from selected venues; drink driving data; risk assessments; the use of 'pseudo patrons'; and knowledge and attitude changes among trained bar staff (n = 88). Compared to control sites the intervention sites showed an immediate pre- to post-test reduction in patrons rated by researchers as extremely drunk and an eventual reduction from pre-test to follow-up in patrons with blood alcohol levels > = 0.08. There was also a small but significant increase in knowledge among bar staff. There was no significant reduction in patrons with blood alcohol levels > = 0.15 or in the number of drink driving offences from intervention sites during the study period. Pseudo drunk patrons were rarely refused service, identification was rarely checked and non-photographic identification was accepted on most occasions. The less than satisfactory outcome is attributed to poor implementation of the training and a lack of support among managers. The positive results from one venue, whose manager embraced the programme, served to highlight the importance of management support. It is suggested that mandatory training and routine enforcement of licensing laws are essential if the goals of responsible serving are to be met
Thermal-structural design study of an airframe-integrated Scramjet
The development and evaluation of a design concept for the cooled structures assembly for the Scramjet engine is discussed. Development concepts for engine subsystems and design concepts for the aircraft/engine interface are included. A thermal protection system was defined which makes it possible to attain a life of 100 hr and 1000 cycles, the specified goal. The coolant equivalence ratio at the Mach 10 maximum thermal loading condition is 0.6, indicating a capacity for airframe cooling. The mechanical design is feasible for manufacture using conventional materials. For the cooled structures in a six module engine, the mass per unit capture area is 1256 kg/sq m. The total mass of a six module engine assembly including the fuel system is 1502 kg
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