Free vibrations of simply-supported beam bridges under moving loads: Maximum resonance, cancellation and resonant vertical acceleration

The advent of high-speed railways has raised many concerns regarding the behaviour of bridges. Particularly, the analysis of the free vibrations generated by each load is of great interest because they can possibly accumulate and create resonance phenomena. Regarding simply supported beams, earlier contributions showed that the free vibrations created by a single moving force are of maximum or zero amplitude (cancellation) for certain speeds. In the present paper new closed-form expressions are given for the cancellation speeds of a generic mode, as well as for the most representative points of maximum amplitude. Similar new results are provided for elastically supported beams as well. A simpler, closed-form approximate expression of the cancellation condition for an elastically supported beam is also derived from the analysis of a single passing load; this approximate formula is in good agreement with the exact results. Knowing a priori the speeds of maximum free vibrations or cancellation is of great interest for experimental tests on bridges, particularly as regards the evaluation of amplitude-dependent magnitudes such as structural damping. Regarding the resonance phenomena, if the resonance speeds coincide with either a maximum free vibration or a cancellation speed, then a maximum resonance or a cancellation of resonance will occur. The most relevant cases thereof have been investigated, and new expressions which allow predicting them for a generic mode are given. Finally, a new approximate formula is proposed for estimating the maximum acceleration of simply supported bridges caused by resonances of the fundamental mode. After extensive numerical testing, the formula has proved to be a useful tool for a first assessment of simply supported bridges according to building codes such as Eurocodes. (C) 2012 Elsevier Ltd. All rights reserved.The authors acknowledge the financial support of the State Secretariat for Research of the Spanish Ministry of Science and Innovation (Secretaria de Estado de Investigacion, Ministerio de Ciencia e Innovacion, MICINN) in the framework of the Research Project BIA2008-04111.Museros Romero, P.; Moliner, E.; Martinez-Rodrigo, M. (2013). Free vibrations of simply-supported beam bridges under moving loads: Maximum resonance, cancellation and resonant vertical acceleration. Journal of Sound and Vibration. 332(2):326-345. https://doi.org/10.1016/j.jsv.2012.08.008326345332

Provision of breast milk after implementation of a breast milk tracking system

https://scholarlycommons.libraryinfo.bhs.org/nurs_presentations2023/1000/thumbnail.jp

Association between obesity and infarct size: insight into the obesity paradox.

Abstract: Background: In patients with coronary heart disease, being overweight or obese is associated with better outcomes, a phenomenon known as the \u27obesity paradox\u27. Despite the high prevalence of obesity in the United Sates, its effects on infarct size are largely unexplored. Methods: Prospective cross-sectional study of 102 consecutive patients admitted with acute myocardial infarction (MI). Standardized forms were used to collect data on body mass index (BMI), waist circumference (WC), cardiovascular risk factors, and medications. Peak troponin I and creatinine phosphokinase (CPK) were used to estimate infarct size. Epicardial and pericardial fat were measured by echocardiography. We used univariate and multivariate analyses to assess whether obesity was associated with infarct size. Correlations between BMI, WC and cardiac fat with cardiac biomarkers were also performed. Results: Mean age was 62±12 years, and 55% were men. Obesity was diagnosed in 69%. On multivariate analysis, obesity was associated with greater infarct size in non-ST elevation MI (p=0.02). A positive correlation was observed between BMI and peak troponin I (rho=0.24, p=0.03), and both, BMI and WC had a positive correlations with CPK levels (rho=0.28, & rho=0.28, both p=0.02). However, in ST elevation MI, obesity was associated with smaller infarct size (p=0.05). Epicardial fat + pericardial fat had a negative correlation with peak CPK levels (rho=-0.36, p=0.05). Conclusions: We observed an opposite association between obesity and infarct size depending on the type of MI. These results were unexpected and may provide insight into the pathophysiology of the obesity paradox

Information fusion from multiple databases using meta-association rules

Nowadays, data volume, distribution, and volatility make it difficult to search global patterns by applying traditional Data Mining techniques. In the case of data in a distributed environment, sometimes a local analysis of each dataset separately is adequate but some other times a global decision is needed by the analysis of the entire data. Association rules discovering methods typically require a single uniform dataset and managing with the entire set of distributed data is not possible due to its size. To address the scenarios in which satisfying this requirement is not practical or even feasible, we propose a new method for fusing information, in the form of rules, extracted from multiple datasets. The proposed model produces meta-association rules, i.e. rules in which the antecedent or the consequent may contain rules as well, for finding joint correlations among trends found individually in each dataset. In this paper, we describe the formulation and the implementation of two alternative frameworks that obtain, respectively, crisp meta-rules and fuzzy meta-rules. We compare our proposal with the information obtained when the datasets are not separated, in order to see the main differences between traditional association rules and meta-association rules. We also compare crisp and fuzzy methods for meta-association rule mining, observing that the fuzzy approach offers several advantages: it is more accurate since it incorporates the strength or validity of the previous information, produces a more manageable set of rules for human inspection, and allows the incorporation of contextual information to the mining process expressed in a more human-friendly format

Systematic review and meta-Analysis of global birth prevalence of clubfoot: A study protocol

IntroductionClubfoot is a common congenital birth defect, with an average prevalence of approximately 1 per 1000 live births, although this rate is reported to vary among different countries around the world. If it remains untreated, clubfoot causes permanent disability, limits educational and employment opportunities, and personal growth. The aim of this systematic review and meta-analysis is to estimate the global birth prevalence of congenital clubfoot.Methods and analysisElectronic databases including MEDLINE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, Global Health, Latin American &amp; Caribben Health Science Literature (LILACS), Maternity and Infant Care, Web of Science, Scopus and Google Scholar will be searched for observational studies based on predefined criteria and only in English language from inception of database in 1946 to 10 November 2017. A standard data extraction form will be used to extract relevant information from included studies. The Joanna Briggs Institute appraisal checklist will be used to assess the overall quality of studies reporting prevalence. All included studies will be assessed for risk of bias using a tool developed specifically for prevalence studies. Forest plots will be created to understand the overall random effects of pooled estimates with 95% CIs. An I2test will be done for heterogeneity of the results (P&gt;0.05), and to identify the source of heterogeneity across studies, subgroup or meta-regression will be used to assess the contribution of each variable to the overall heterogeneity. A funnel plot will be used to identify reporting bias, and sensitivity analysis will be used to assess the impact of methodological quality, study design, sample size and the impact of missing data.Ethics and disseminationThis review will be conducted completely based on published data, so approval from an ethics committee or written consent will not be required. The results will be disseminated through a peer-reviewed publication and relevant conference presentations.PROSPERO registration numberCRD42016041922.</jats:sec

EFICACIA, ADHERENCIA Y COSTO DE CIPROFLOXACINO EN TABLETAS EN DIARREA DISENTÉRICA

OBJETIVO, determinar la adherencia, eficacia y costo del tratamiento con ciprofloxacino en niños con diarrea disentérica.MATERIAL Y MÉTODOS,   el estudio se realizó en 23 pacientes de 2 meses a 14 años de edad, de ambos sexos con diagnóstico clínico de diarrea disentérica, atendidos en consulta externa del Hospital Belén de Trujillo, Hospital de ESSalud del distrito de Florencia de Mora y en un consultorio de práctica privada ubicado en el cercado del distrito de Trujillo entre enero a noviembre del año 2013; el tratamiento se realizó con ciprofloxacino en tabletas, 20 mg por kilo de peso corporal dos veces al día, cada 12 horas, el control y respuesta clínica al tratamiento se evaluó a las 24, 48 y 72 horas, con la revisión de las características de la última deposición del niño. El tratamiento con ciprofloxacino fue considerado eficaz si se evidencio una disminución gradual del moco y/o sangre en las deposiciones en las primeras 48 horas, con un máximo de 72 horas de iniciado el tratamiento.RESULTADOS, se encontró  que el  86,95%  de los niños mostraron mejoría a las 72 horas de  tratamiento, la adherencia al mismo fue de 91,3%, y el costo total fue cinco nuevos soles.CONCLUSIONES, El ciprofloxacino es eficaz en el tratamiento de la diarrea disentérica, su accesibilidad con respecto al costo y adherencia se puede lograr si se prescribe la tableta triturada y disuelta en una bebida agradable para el niño. Palabras  clave: diarrea  disentérica, adherencia,  eficacia, ciprofloxacino (BIREME DeCS

Polypyrrole-Fe2O3 nanohybrid materials for electrochemical storage

We report on the synthesis and electrochemical characterization of nanohybrid polypyrrole (PPy) (PPy/Fe2O3) materials for electrochemical storage applications. We have shown that the incorporation of nanoparticles inside the PPy notably increases the charge storage capability in comparison to the “pure” conducting polymer. Incorporation of large anions, i.e., paratoluenesulfonate, allows a further improvement in the capacity. These charge storage modifications have been attributed to the morphology of the composite in which the particle sizes and the specific surface area are modified with the incorporation of nanoparticles. High capacity and stability have been obtained in PC/NEt4BF4 (at 20 mV/s), i.e., 47 mAh/g, with only a 3% charge loss after one thousand cyles. The kinetics of charge–discharge is also improved by the hybrid nanocomposite morphology modifications, which increase the rate of insertion–expulsion of counter anions in the bulk of the film. A room temperature ionic liquid such as imidazolium trifluoromethanesulfonimide seems to be a promising electrolyte because it further increases the capacity up to 53 mAh/g with a high stability during charge–discharge processes