4,206 research outputs found

    Computerized structural mechanics for 1990's: Advanced aircraft needs

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    The needs for computerized structural mechanics (CSM) as seen from the standpoint of the aircraft industry are discussed. These needs are projected into the 1990's with special focus on the new advanced materials. Preliminary design/analysis, research, and detail design/analysis are identified as major areas. The role of local/global analyses in these different areas is discussed. The lessons learned in the past are used as a basis for the design of a CSM framework that could modify and consolidate existing technology and include future developments in a rational and useful way. A philosophy is stated, and a set of analyses needs driven by the emerging advanced composites is enumerated. The roles of NASA, the universities, and the industry are identified. Finally, a set of rational research targets is recommended based on both the new types of computers and the increased complexity the industry faces. Computerized structural mechanics should be more than new methods in structural mechanics and numerical analyses. It should be a set of engineering applications software products that combines innovations in structural mechanics, numerical analysis, data processing, search and display features, and recent hardware advances and is organized in a framework that directly supports the design process

    Approximation of Rough Functions

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    For given p[1,]p\in\lbrack1,\infty] and gLp(R)g\in L^{p}\mathbb{(R)}, we establish the existence and uniqueness of solutions fLp(R)f\in L^{p}(\mathbb{R)}, to the equation f(x)af(bx)=g(x), f(x)-af(bx)=g(x), where aRa\in\mathbb{R}, bR{0}b\in\mathbb{R} \setminus \{0\}, and ab1/p\left\vert a\right\vert \neq\left\vert b\right\vert ^{1/p}. Solutions include well-known nowhere differentiable functions such as those of Bolzano, Weierstrass, Hardy, and many others. Connections and consequences in the theory of fractal interpolation, approximation theory, and Fourier analysis are established.Comment: 16 pages, 3 figure

    INCIDENCES OF STAPHYLOCOCCUS SPECIES IN SURGICAL SITE INFECTIONS-PROSPECTIVE STUDY FROM TERTIARY CARE CENTER, COIMBATORE, TAMILNADU

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    Objective: Surgical site infection (SSIs) is of great importance to regulatory agencies and public because of their clinical implication and occurrence. Human skin is populated with normal bacterial flora, which also gains access during immunocompromised state causing infection. This present study focuses on surveillance of SSIs with emphases over Staphylococcus species infection among patients from tertiary care centers of Coimbatore, TamilNadu, India.Methods: Clinical samples were collected and plated on mannitol salt agar (MSA) medium for isolation of Staphylococcus species. Furthermore, other conventional methods like Gram staining, catalase reaction were also performed in strict aseptic conditions with standard microbiological procedures for sample processing.Results: A total of 221 samples were collected and processed which resulted in 42.08% positivity with 59.13% Gram positive strains. Staphylococcus species were more prevalent in the Gram positive isolates, where other Gram negative microorganisms such as E. coli, P. aeruginosa, K. pneumoniae, M. morganii, E. faecalis, Enterobacter species, A. baumanii, S. marcescens and P. mirabilis were also isolated. The antibiogram pattern of the Staphylococcus species revealed resistance to antibiotics.Conclusion: This study has shown the prevalence of Staphylococcus species among SSIs, implicating the importance of further extended surveillance for better understanding of the prevalence rate and antimicrobial resistance pattern.Â

    Synthesis and characteristics of polyarylene ether sulfones

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    A method utilizing potassium carbonate/dimethyl acetamide, as base and solvent respectively, was used for the synthesis of several homopolymers and copolymers derived from various bisphenols. It is demonstrated that this method deviates from simple second order kinetics; this deviation being due to the heterogeneous nature of the reaction. Also, it is shown that a liquid induced crystallization process can improve the solvent resistance of these polymers. Finally, a Monte Carlo simulation of the triad distribution of monomers in nonequilibrium copolycondensation is discussed

    Shannon entropy of brain functional complex networks under the influence of the psychedelic Ayahuasca

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    The entropic brain hypothesis holds that the key facts concerning psychedelics are partially explained in terms of increased entropy of the brain's functional connectivity. Ayahuasca is a psychedelic beverage of Amazonian indigenous origin with legal status in Brazil in religious and scientific settings. In this context, we use tools and concepts from the theory of complex networks to analyze resting state fMRI data of the brains of human subjects under two distinct conditions: (i) under ordinary waking state and (ii) in an altered state of consciousness induced by ingestion of Ayahuasca. We report an increase in the Shannon entropy of the degree distribution of the networks subsequent to Ayahuasca ingestion. We also find increased local and decreased global network integration. Our results are broadly consistent with the entropic brain hypothesis. Finally, we discuss our findings in the context of descriptions of "mind-expansion" frequently seen in self-reports of users of psychedelic drugs.Comment: 27 pages, 6 figure

    Estimation of Optimum Tilt Angle of PV Panel for Maximum Energy Harvesting

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    In solar energy conversion system harvesting of maximum energy is necessary in order to maximize the utilization of available energy. The maximum energy from the solar panel can be extracted by keeping solar panel in an optimum tilt angle. Various approaches are available to find optimum tilt condition of the solar panel.  In this work two different positions of the panel such as fixed tilt, seasonal tilt were analyzed using isotropic and anisotropic models. Among the various models available in the above said broad category six models such as Liu-Jordan, Koronokis Model, Badescu model, Hay and Davis model, Reindel model,  Hay&Davis and Reindel & Klucher combined model are incorperated to predict the  monthly average of daily global solar irradiation of the inclined panels held in SASTRA University, Thanjavur (India) location. Statistical tests have been performed in order to evaluate the consequences predicted by the models with the experimental results. Finally a detailed comparison between fixed tilt and seasonal tilt of the panel has been carried out and the suitable model for this location is also suggested

    Hypertension Prevalence Based on Blood Pressure Measurements on Two vs. One Visits: A Community-Based Screening Programme and a Narrative Review.

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    We assessed the difference in the prevalence of hypertension in community surveys when blood pressure (BP) was measured on two vs. one visits and its impact on hypertension awareness, treatment and control proportions. A community-based BP screening programme was conducted in public places in the Seychelles (619 adults) and BP was rechecked a few days later among untreated participants with high BP (≥140/90 mmHg). A narrative review of the literature on this question was also conducted. Only 64% of untreated participants with high BP still had high BP at the second visit. The prevalence of hypertension in the whole sample decreased by 13% (from 33.8% to 29.5%) when BP was measured on two vs. one visits. These results concurred with our findings in our narrative review based on 10 surveys. In conclusion, the prevalence of hypertension can be markedly overestimated in community surveys when BP is measured on two vs. one visits. The overestimation could be addressed by measuring BP on a second visit among untreated individuals with high BP or, possibly, by taking more readings at the first visit. These findings have relevance for clinical practice, policy and surveillance
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