142,758 research outputs found

    Impact Damage Tolerance of Composite Laminates with Through-The-Thickness Stitches

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    The ability of through-the-thickness stitches to contain damage during a low-velocity impact event and increase the residual strength of stitched panels was investigated in this research. The impact response, spread of interlaminar delaminations, dent depth, surface damage, and static residual strength after impact were studied for carbon-epoxy specimens fabricated from HTS40 TohoTenax standard modulus fibers, stitched together with Vectran 1200 denier thread and infused with API 1078 resin after through-the-thickness stitching. Three different stitch patterns were used to explore the ability to arrest impact damage during and after impact. Simply supported boundary conditions were maintained during the impact testing. Non-destructive evaluations were performed using ultrasonic C-scans and X-ray computed tomography (CT) imaging to determine the shape, size, and location of delaminations. Results indicate that while the dynamic response during the impact event was almost the same for the unstitched specimens and all stitch patterns considered, the extent of delamination and the compression strength after impact varied greatly. For both the 60 J and 80 J impact energies, the delamination area was significantly less for the stitched specimens than for the unstitched specimens, but the range of delamination areas among the stitch patterns was much larger for the lower impact energy than for the greater impact energy. Similarly, while the presence of stitching influenced the compression after impact strength, the strength values for all stitch patterns were very similar. These results are a step toward quantifying the influence of through-the-thickness stitching

    Capital One Mobile Authentication: Authentication using Biometric

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    Capital One, a large US bank, is currently providing customers with a mobile servicing experience. One of the features of the mobile servicing app is easy and convenient access to account information. Capital One currently allows users to authenticate using a traditional username / password, their registered SureSwipe feature and even their finger on supported devices. The project\u27s goal is to evaluate the viability of retinal recognition as a new method for biometric authentication. By successfully developing this project, the application could offer retinal recognition as an additional biometric authentication option to customers. This can be used to help eliminate the risk of users losing their passwords as well as to solve many security concerns related to them. Two development aspects: • Mobile Application - the user interface that handles biometric authentication using the EyeVerify SDK • API - the back-end that handles information and account management using node.js and MongoDB Throughout two semesters, the team has managed to meet the application and business requirements, as well as produce working prototypes at different stages. Along the development process, the team learned Swift, Objective-C, MongoDB, as well as RESTful API design patterns. Furthermore, the team also gained experience in Swift and Objective-C interoperability, networking, and API integration from mobile clients. While retinal recognition has many advantages over other methods of biometric authentication, the team would not necessarily recommend it at this time given the current SDK options. Throughout the project it proved to be difficult to work with and restrictive in its functionality. In conclusion, the team would recommend continuing to review additional solutions.https://scholarscompass.vcu.edu/capstone/1092/thumbnail.jp

    Isolation, identification and characterization of Lactobacillus species from fermented locust bean (Parkia biglobosa) for use as probiotics in the aquaculture industry

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    Probiotics are a promising feed additive to stimulate animal growth and secure a low disease response in aquaculture industry where there are high stocking densities in shrimp and fish production. Fermented locust beans (Parkia biglobosa) are known to be rich in protein and used as food condiment. Probiotic bacteria were isolated from this locally available food material. Culture and characterizations of isolates were carried out. Sugar fermentation patterns were determined by using an API 50 CHL system and incubation were performed anaerobically at 37~'C. MRS broth culture grown at 37~'C overnight was added to 9ml of MRS Agar and the bacteria were incubated at 37~'C for 24 and 48 hrs. Discrete and single colony of lactobacillus was isolated using colony morphology and biochemical tests. The most significant viable taxa isolated was Lactobacillus fermentum at a pH range of (3.0-8.0), while the least viable taxa isolated was Leuconostoc mesenteroides ssp. Microscopically they were Grampositive, rod shaped, non- motile, catalase negative and absence of Endospore

    Introduction to Microservice API Patterns (MAP)

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    The Microservice API Patterns (MAP) language and supporting website premiered under this name at Microservices 2019. MAP distills proven, platform- and technology-independent solutions to recurring (micro-)service design and interface specification problems such as finding well-fitting service granularities, rightsizing message representations, and managing the evolution of APIs and their implementations. In this paper, we motivate the need for such a pattern language, outline the language organization and present two exemplary patterns describing alternative options for representing nested data. We also identify future research and development directions

    Programming patterns and development guidelines for Semantic Sensor Grids (SemSorGrid4Env)

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    The web of Linked Data holds great potential for the creation of semantic applications that can combine self-describing structured data from many sources including sensor networks. Such applications build upon the success of an earlier generation of 'rapidly developed' applications that utilised RESTful APIs. This deliverable details experience, best practice, and design patterns for developing high-level web-based APIs in support of semantic web applications and mashups for sensor grids. Its main contributions are a proposal for combining Linked Data with RESTful application development summarised through a set of design principles; and the application of these design principles to Semantic Sensor Grids through the development of a High-Level API for Observations. These are supported by implementations of the High-Level API for Observations in software, and example semantic mashups that utilise the API
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