Browsing by Subject "API"
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Item Evaluation of bearing capacity design for shallow foundation in cohesionless soil with API and ISO(2013-05) Lai, Ying; Gilbert, Robert B. (Robert Bruce), 1965-A database with 217 cases of load tests on shallow foundations, mostly in/on granular soils, was compiled. With this information, the comparison of predicted bearing capacity using different design methods, the American Petroleum Institute Recommended Practice 2A-LRFD (API RP2A-LRFD,1989), the American Petroleum Recommended Practice 2GEO (API RP2GEO, 2011), and International Standard Organization (ISO, 2003) is carried out. The answer to which standard makes a good prediction varies with the way to define failure load from load-displacement curve. Overall, ISO has a higher prediction compared with API RP2A and API RP2GEO. For the cases with vertical concentric loading conditions, if the capacity at plastic region and is defined as failure load, then the prediction by API RP2A is closest to measured capacity. If the capacity corresponding with 10% of footing width is considered as failure load, then the API RP2A and API RP2GEO underestimate the capacity, while ISO is in a good agreement with capacity corresponding with 10% of footing width. The prediction by API RP2GEO generally has a good agreement with capacity at tangent intersection region. In most of the cases with vertical eccentric loading, all three standard underestimate the measured capacities no matter which interpreted capacities is considered as failure load, while ISO makes slightly overprediction at the lower range of eccentricities and underprediction at higher range of eccentricities for some cases. In the inclined loading condition, the prediction by API RP2GEO is minimum among the three standards, while ISO proposed the highest prediction. All three prediction underestimate the capacity under inclined loading condition. From this study, it is found that small scale load laboratory test reveals a qualitative understanding with impact of vertical eccentric and concentric inclined loading on ultimate capacities. However, it is hard to detect a clear best prediction based on small scaled laboratory load test results. The well-controlled field test results, especially the field tests with vertical eccentric and concentric inclined loading condition, are valuable to evaluate the consistency of predicted capacity by three standards.Item A novel cryogenic particle engineering technology to micronize water-insoluble drugs and enhance their dissolution properties : spray-freezing into liquid(2002-08) Rogers, True Lawson; Williams, Robert O., 1956-Poorly water-soluble and insoluble chemical agents are routinely investigated in the pharmaceutical industry for pharmacological activity, but many of these are never commercialized due to inadequate dissolution and subsequent low oral bioavailability following oral administration. The bioavailability of many hydrophobic active pharmaceutical ingredients (APIs) can be increased by enhancing their aqueous dissolution. Spray-Freezing into Liquid (SFL) is a novel particle engineering technology that has been demonstrated in the following studies to significantly enhance the dissolution of insoluble APIs. The ultimate goal throughout the studies was to produce micronized SFL powders where the inherently insoluble API would be completely dissolved in aqueous dissolution media within a minimal amount of time (less than ca. 10 minutes). The SFL particle engineering technology is a novel process that was developed, investigated and optimized in order to broaden its applications in pharmaceutical drug delivery systems. Micronized SFL powders were compared head-to-head with powders produced from milling, co-grinding with excipients and slow freezing of liquids containing dissolved API and excipients followed by lyophilization. To strengthen the applicability of the SFL particle engineering technology, studies were conducted where micronized SFL powders were exposed to various stability storage conditions, and characterized to determine the influences of the exposure conditions and time on the physicochemical properties of the powder containing the API. The utility of the SFL process was further enhanced by developing an atmospheric freeze-drying (ATMFD) technique to obtain dry micronized SFL powders. Micronized SFL powders dried by ATMFD were compared to micronized SFL powders dried by vacuum-freeze drying to determine any changes in physicochemical properties or dissolution profiles as a function of the drying technique utilized. The usefulness of the SFL particle engineering technology was broadened when it was found that highly concentrated emulsions could be processed by SFL to produce micronized powders that rapidly wetted and dissolved in dissolution media. Micronized SFL powders produced from emulsion were investigated and compared to slowly frozen agglomerates from emulsion and a micronized SFL powder from solution. As a result of the following studies, the enabling examples using the SFL platform were designed to illustrate applications of the SFL technology as a tool to enhance the aqueous dissolution of poorly water-soluble and insoluble APIs. Therefore, it was demonstrated that this novel particle engineering technology is a feasible method that may be used in the pharmaceutical industry to solve the ever-present solubility and dissolution problems associated with poorly water-soluble or insoluble APIs, or chemical agents being investigated for pharmacological activity as future APIsItem Perceptions and Expressions of Social Presence During Conversations on Twitter(2012-02-14) Pritchett, KellyComputer-mediated environments such as social media create new social climates that impact communication interactions in un-mediated environments. This study examined social variables during conversations on Twitter through a qualitative document analysis that coded messages into affective, interactive or cohesive categories. Perceived social presence, participant satisfaction, and relationships between social presence and satisfaction among Twitter users during streaming conversations were examined through an online questionnaire that was created using qualtrics.com and made available to respondents over a one-week period. The researcher concluded that most social variables in the Twitter conversations of this study fall into the interactive social presence category. In addition, each category of responses functions in a different way to foster social presence. Two groups of survey respondents agreed with 10 out of 21 and 13 out of 21 statements about social presence and 10 out of 13 and 12 out of 13 statements about satisfaction. Findings indicated that positive and negative relationships exist between social presence and satisfaction. Both conversations in this study appeared to be successful. Therefore, agricultural communicators should feel comfortable using CMC more frequently to circulate agricultural information among populations across the globe. It was recommended that further research be conducted to examine social presence among new topics, populations, and other forms of CMC.Item Systems Interoperability and Collaborative Development for Web Archiving - Filling Gaps in the IMLS National Digital Platform(2016-05-25) Mumma, Courtney; Phillips, Mark; Internet Archive; University of North TexasThe Institute of Museum and Library Services (IMLS) awarded a National Leadership Grant, in the National Digital Platform category, to a proposal by Internet Archive’s Archive-It, Stanford University Libraries (DLSS and LOCKSS), University of North Texas, and Rutgers University. The $353,221 grant will support the project “Systems Interoperability and Collaborative Development for Web Archiving,” a two-year research project to test economic and community models for collaborative technology development, prototype system integration through development of Export APIs, and build community participation in web archiving development and new research and access tools. The project supports the National Digital Platform funding priority of IMLS by increasing access to shared services and infrastructure while building capacity for broader community input in technology development. Project outcomes will promote system integration, facilitate increased distributed preservation of archived data, and help support new global and local access models possible through export APIs, with an eye towards modeling post-grant interoperable systems architectures. Archive-It’s status as widely-used, shared web archiving infrastructure ensures broad community impact and makes possible the involvement of institutions of all sizes in project work. The involvement of Stanford University Libraries builds on their work in the Hydra community and with digital preservation services. UNT contributes experience in digital library and web archiving technology development and Rutgers’ work on research uses of web archives ensures the involvement of downstream user communities. Overall, the project will lay the groundwork for future collaboration around interoperability that will enhance the integration of disparate systems, increase local preservation, and improve the discoverability and use of web archives. Mark Phillips of UNT and Courtney Mumma of IA will describe the grant and provide an update about the work completed in the first six months of activity. Attendees will be invited to participate in an active and growing community, a key component in the grant’s success and the work’s sustainability.Item Upper Bound Analysis of Bearing and Overturning Capacities of Shallow Foundations in Soft Clay(2013-12-03) Hartsfield, Randal JamesThis thesis presents a method to calculate the bearing and overturning capacity of a shallow foundation installed in soft clay using the upper bound method of plasticity. Mudmats are commonly used shallow foundations in offshore projects and are often eccentrically loaded. As economics and project requirements change, mudmats have evolved from simple circles and rectangles to more complex geometries. Computing the bearing and overturning capacities of such complex geometries using existing methods outlined in API procedures becomes difficult, as these procedures have been established for simple shapes. FEM is an alternative and established method for analysis, but these programs can be costly. In this thesis, the procedures for analysis using the upper bound method of plasticity are outlined and used to compute the bearing and overturning interaction for several foundations of varying shapes and undrained shear strength profiles. These results are compared to output of the FEM analysis program ABAQUS for validation. The conclusions of this case study are that the upper bound method of plasticity provides a reasonable prediction of the bearing and overturning capacity of an eccentrically loaded mudmat foundation, though considerations should be made when significant torsion or overturning moments in multiple directions are expected.