595 research outputs found

    PIC 18F452 implementation of digital filters

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    This research hopes to explore the computational limits of the PIC18f452 chip by encompassing the designing and implementation of two types of filters for the PIC 18F452 microcontroller. The main purpose of this research is to implement a floating-point least mean square (LMS) error adaptive filter and its secondary goal is a fixed-point implementation of finite impulse response (FIR) filter. FIR filters are specified via a graphical user interface (GUI) and upon demand, optimized C-language code is generated for the popular CCS PIC C-Compiler. In is the intent of this research to learn whether FIR filters can be made computationally viable on the PIC18 chips, can they run stably with reliable and repeatable performance? What is the minimum execution time possible at the processing limits of the chip? And how is filter attenuation affected when taps are scaled down from floating-point to fixed point? The FIR filter code generation software developed during this study allows graphical specification, inspection of response curves. (Abstract shortened by UMI.)

    Sodar Structures of Inversion Characteristics Over Calcutta

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    Endothelial cell CD36 deficiency prevents normal angiogenesis and vascular repair

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    Endothelial cells (ECs) maintain vascular integrity and mediate vascular repair and angiogenesis, by which new blood vessels are formed from pre-existing blood vessels. Hyperglycemia has been shown to increase EC angiogenic potential. However, few studies have investigated effects of fatty acids (FAs) on EC angiogenesis. Cluster of differentiation 36 (CD36) is a FA transporter expressed by ECs, but its role in EC proliferation, migration, and angiogenesis is unknown. We sought to determine if circulating FAs regulate angiogenic function in a CD36-dependent manner. CD36-dependent effects of FAs on EC proliferation and migration of mouse heart ECs (MHECs) and lung ECs (MLECs) were studied. We used both silencing RNA and antisense oligonucleotides to reduce CD36 expression. Oleic acid (OA) did not affect EC proliferation, but significantly increased migration of ECs in wound healing experiments. CD36 knockdown prevented OA-induced increases in wound healing potential. In EC transwell migration experiments, OA increased recruitment and migration of ECs, an effect abolished by CD36 knockdown. Phospho-AMP-activated protein kinase (AMPK) increased in MHECs exposed to OA in a CD36-dependent manner. To test whethe

    User perspectives on Implanon NXT in South Africa: A survey of 12 public-sector facilities

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    Background. Implanon NXT, a long-acting reversible contraceptive, was introduced in South Africa (SA) in early 2014, aiming to expand the method mix and increase its effectiveness. Initial uptake was high, but has since declined considerably. In these early years after the implant’s introduction, it is important to identify reasons for the decline, and remedy gaps in services. Objectives. To determine periods of use, reasons for the use and early removal of the implant Implanon NXT. Methods. In 2016, we recruited 152 women from six clinics in the City of Johannesburg, and six in North West Province, SA. A semistructured interview was administered to 91 women currently using the implant and 61 previous users. We examined user perspectives, factors influencing women’s experiences with the implant and reasons for discontinuation. Results. The participants’ mean age was 30 years, with only 15% aged <25. Implant uptake was motivated by convenience (less frequent visits required than for short-acting methods) and by favourable views of the method among friends, family and healthcare providers. Only about a quarter of women recalled being counselled pre-insertion about implant effectiveness, and half about side-effects pre-insertion. Among discontinuers, the median time to device removal was 8 months (interquartile range 6 - 12), and this was primarily as a result of sideeffects (90%), especially bleeding-pattern changes and headaches. Removals were most common among married and cohabiting women, often ascribed to the effects of bleeding on their sexual relationships. Rumours and misinformation contributed to some removals. Overall, women’s experiences with the implant were rated ‘good’ or ‘very good’ by 74% of those continuing use, many of whom reported not having experienced any side-effects or that these had diminished over time. Conclusion. Levels of acceptability among continuing users were high, mainly linked to the method’s convenience. While early favourable views drove uptake, negative perceptions, if unaddressed, may now undermine services. Deficiencies in counselling around effectiveness and side-effects may extend to contraceptive services more generally. Women require more intensive support when experiencing sideeffects, including effective systematic approaches to ameliorating bleeding and headaches. Implant services could specifically target young women and first-time contraceptive users. These actions together could reverse the persistent decline in implant use in SA. S Afr Med J 2017;107(10):815-82

    A Numerical Simulation of Turbulent Flow through a Curved Duct

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    This paper presents the comparison the results of an experimental work with a numerical work keeping the geometry of the test duct and inlet boundary conditions unaltered. The numerical simulation is validated with the experimental results based on the wall y+ approach for different turbulence models suited for this type of geometry. The experimental work is carried out at mass averaged mean velocity of 40m/s with the measurement of total pressure by a pre-calibrated multi-hole pressure probe and the results presented in the form of a pressure contours in 2-D. For validation of the numerical results Standard k-ε, k-ω and Reynolds Stress Model (RSM) are used to solve the closure problem. The turbulence models are investigated in the commercial CFD code of Fluent using y+ value as guidance in selecting the appropriate grid configuration and turbulence model. Based on the wall y+ values for different turbulence models, it is concluded in the present study that the mesh resolving the fully turbulent region is sufficiently accurate in terms of qualitative features and RSM turbulence model predicts the best results while comparing with the experimental results

    Understanding psycholinguistic behavior of predominant drunk texters in social media

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    In the last decade, social media has evolved as one of the leading platform to create, share, or exchange information; it is commonly used as a way for individuals to maintain social connections. In this online digital world, people use to post texts or pictures to express their views socially and create user-user engagement through discussions and conversa
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