1,855 research outputs found

    Effect of the curing time on the numerical modelling of the behaviour of a chemically stabilised soft soil

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    The ability of the Modified Cam Clay (MCC) model combined with the Von Mises (VM) model, considering the effect of curing time on the enhancement of the mechanical properties of a chemically stabilised soft soil is examined. The evolution of the strength and stiffness over time is based on the results of undrained compressive strength (UCS) tests carried out for different curing times (from 28 days to 360 days). Initially, the MCC/VM models associated with the effect of curing time are validated by CIU triaxial tests, for curing times of 28 and 90 days. Finally, the behaviour of an embankment built on a soft soil reinforced with deep mixing columns is predicted based on the previously validated models. The results show that the increase of curing time of the DMCs slightly decreases the settlement obtained with a curing time of 28 days

    Hysteroscopy and pain: what risk factors should we consider in office hysteroscopy? are there really any?

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    Background: Office hysteroscopy is the gold standard in abnormal uterine bleeding and an indispensable tool in modern gynecology. It is becoming increasingly popular leading to examinations and even operations without anesthesia as it is accurate, cheap and well tolerated. However, pain is still a limitation. The objective of the study was to determine if pain perception is linked to clinical predictors and how well they correlate with pain score.Methods: Prospective observational trial enrolled one hundred and four women; four cases were excluded. One hundred cases were included and analyzed. Selection criteria: patients scheduled for Office Hysteroscopy who accepted to participate and had no contraindication for procedure.Results: A ten centimeter visual analogue scale was used for pain evaluation. Presumed variables such as menopause, pelvic pain, previous cesarean section and cervical surgery, and body mass index were analyzed by ordered regression using standard statistical software tools.Conclusions: Correlation between predictive factors and pain reporting showed no significance (p>0.05) except for body mass index which was found to significantly correlate to discomfort (p<0.05)

    Pain, anxiety and patient satisfaction in office hysteroscopy, is there a link? Are patient satisfaction questionnaires reliable?

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    Background: Office hysteroscopy is becoming increasingly popular leading to examinations and operations without anesthesia.  Anxiety is always present before an aversive medical intervention and may play a role in pain perception. The objectives of the study were to determine if pain perception is linked to anxiety and how well patient satisfaction questionnaires correlate with pain.Methods: Prospective observational study enrolled one hundred and four women. One hundred cases were included and analyzed. Patients scheduled for office hysteroscopy, who accepted to participate and were able to answer questionnaires.Results: A ten centimeter visual analogue scale was used for pain evaluation and the State anxiety-trait inventory for adults questionnaires for anxiety assessment. Three other satisfaction questionnaires, each consisting of three answers, were also administered and investigated. Analysis was performed using SPSS 22.0 IBM for windows software tools.Conclusions: Correlation between anxiety and pain reporting showed no influence with anxiety trait (p value = 0.4170) and a mild correlation with anxiety state (p value = 0.146). Classification of pain into “no pain”, “mild pain”, “moderate pain” and “severe pain”, should be revised in office hysteroscopy: for visual analogue scale, scores of 2.5 to 3 cm correspond to the lower boundary of moderate pain and scores above limit 6.5 cm should define pain as severe. Satisfaction questionnaires significantly correlated to discomfort (p value <0.001) and may be a practical option to assess tolerance of medical procedures with excellent sensibility and specificity

    Jamming and percolation of linear k -mers on honeycomb lattices

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    Numerical simulations and finite-size scaling analysis have been performed to study the jamming and percolation behavior of elongated objects deposited on two-dimensional honeycomb lattices. The depositing particle is modeled as a linear array of length k (so-called k -mer), maximizing the distance between first and last monomers in the chain. The separation between k -mer units is equal to the lattice constant. Hence, k sites are occupied by a k -mer when adsorbed onto the surface. The adsorption process starts with an initial configuration, where all lattice sites are empty. Then, the sites are occupied following a random sequential adsorption mechanism. The process finishes when the jamming state is reached and no more objects can be deposited due to the absence of empty site clusters of appropriate size and shape. Jamming coverage θ j , k and percolation threshold θ c , k were determined for a wide range of values of k ( 2 ≤ k ≤ 128 ). The obtained results shows that ( i ) θ j , k is a decreasing function with increasing k , being θ j , k → ∞ = 0.6007 ( 6 ) the limit value for infinitely long k -mers; and ( i i ) θ c , k has a strong dependence on k . It decreases in the range 2 ≤ k < 48 , goes through a minimum around k = 48 , and increases smoothly from k = 48 up to the largest studied value of k = 128 . Finally, the precise determination of the critical exponents ν , β , and γ indicates that the model belongs to the same universality class as 2D standard percolation regardless of the value of k considered.Fil: Iglesias Panuska, G. A.. Universidad Nacional de San Luis; ArgentinaFil: Centres, Paulo Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Ramirez Pastor, Antonio Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentin

    A THERP/ATHEANA Analysis of the Latent Operator Error in Leaving EFW Valves Closed in the TMI-2 Accident

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    This paper aims at performing a human reliability analysis using THERP (Technique for Human Error Prediction) and ATHEANA (Technique for Human Error Analysis) to develop a qualitative and quantitative analysis of the latent operator error in leaving EFW (emergency feed-water) valves closed in the TMI-2 accident. The accident analysis has revealed a series of unsafe actions that resulted in permanent loss of the unit. The integration between THERP and ATHEANA is developed in a way such as to allow a better understanding of the influence of operational context on human errors. This integration provides also, as a result, an intermediate method with the following features: (1) it allows the analysis of the action arising from the plant operational context upon the operator (as in ATHEANA), (2) it determines, as a consequence from the prior analysis, the aspects that most influence the context, and (3) it allows the change of these aspects into factors that adjust human error probabilities (as in THERP). This integration provides a more realistic and comprehensive modeling of accident sequences by considering preaccidental and postaccidental contexts, which, in turn, can contribute to more realistic PSA (Probabilistic Safety Assessment) evaluations and decision making

    Guide For Recommended Practices To Perform Crack Tip Opening Displacement Tests In High Strength Low Alloy Steels

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    Fracture mechanics approach is important for all mechanical and civil projects that might involve cracks in metallic materials, and especially for those using welding as a structural joining process. This methodology can enhance not only the design but also the service life of the structures being constructed. This paper includes detailed consideration of several practical issues related to the experimental procedures to assess the fracture toughness in high strength low alloy steels (HSLA) using the crack tip opening displacement (CTOD) parameter, specifically pipeline steels for oil and gas transportation. These considerations are important for engineers who are new in the field, or for those looking for guidelines performing different procedures during the experimentation, which usually are difficult to understand from the conventional standards. We discuss on topics including geometry selection, number of replicate tests, fatigue precracking, test procedure selection and realization, reports of results and other aspects.213290302Colciencias [512]PetrobrasLNNano/CNPE

    Células de linhagem McCoy como um possível modelo contendo receptores CD4+ para estudos da replicação do HIV

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    Several studies have recently shown the use of recombinant rabies virus as potential vector-viral vaccine for HIV-1. The sequence homology between gp 120 and rabies virus glycoprotein has been reported. The McCoy cell line has therefore been used to show CD4+ or CD4+ like receptors. Samples of HIV-1 were isolated, when plasma of HIV-1 positive patients was inoculated in the McCoy cell line. The virus infection was then studied during successive virus passages. The proteins released in the extra cellular medium were checked for protein activity, by exposure to SDS Electrophoresis and blotting to nitro-cellulose filter, then reacting with sera of HIV positive and negative patients. Successive passages were performed, and showed viral replication, membrane permeabilization, the syncytium formation, and the cellular lysis (cytopathic effect). Flow cytometry analysis shows clear evidence that CD4+ receptors are present in this cell line, which enhances the likelihood of easy isolation and replication of HIV. The results observed allow the use of this cell line as a possible model for isolating HIV, as well as for carrying out studies of the dynamics of viral infection in several situations, including exposure to drugs in pharmacological studies, and possibly studies and analyses of the immune response in vaccine therapies.Recentes estudos demonstraram o uso do vírus raiva como modelo vetor para produzir vacinas expressando as glicoproteínas do vírus HIV-1. A homologia na seqüência entre gp120 do vírus HIV-1 e a glicoproteína G do vírus rábico já foi previamente relatada. Devido a estes fatos a linhagem de célula McCoy utilizada com sucesso para a replicação do vírus rábico foi utilizada para demonstrar a replicação do HIV-1. Amostra de HIV-1 foi isolada de plasma de um paciente soro positivo e inoculada em células de linhagem McCoy e então a infecção viral foi estudada em passagens sucessivas do vírus nesta célula. As proteínas liberadas no meio extra celular foram analisadas quanto a atividade biológica pela técnica de eletroforese em gel de poliacrilamida e imunotransferência em membrana de nitro-celulose reagindo com soros positivos para HIV-1 e soros de pacientes negativos. As passagens sucessivas do HIV-1 em células demonstraram a replicação viral, o aumento da permeabilidade da membrana citoplasmática, a formação de sinsício e lise celular. Análises com citometria de fluxo mostraram com clara evidência a presença de receptores CD4+ o que possivelmente deve ser a causa que possibilita a facilidade do isolamento e replicação do vírus HIV-1 nesta célula. Concluindo os resultados observados permitem utilizar esta linhagem celular como um possível modelo para isolamentos de HIV, bem como realizar estudos da dinâmica de infecção viral em diversas situações inclusive de exposição a drogas em estudos farmacológicos, e talvez estudos e análises da resposta imune em terapias vacinais
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