4,078 research outputs found
Guided Microwave Detection of Corrosion Product in Insulated Pipelines
Corrosion under insulation (CUI) is a common cause of pipeline failure in the oil and gas industry. Its detection with conventional inspection techniques is challenging due to the presence of the insulation layer and a protective metallic cladding that prevent direct access to the pipe surface. Guided microwave testing has been proposed as a cost-effective approach to screen an extended length of a pipeline for the presence of water, which is a necessary precursor for CUI. The pipe and metallic cladding naturally form a large coaxial transmission line in which the insulation acts as a dielectric and supports the propagation of microwave signals. The inspection is performed by launching the signal from an array of antennas permanently installed at one location along the pipeline. Wet insulation is then detected according to the radar principle since water results in the partial reflection of the incident microwave owing to the permittivity contrast between dry and wet insulation. This paper reviews the underpinning principles of longrange guided microwave testing and presents a new study aimed at enhancing the selectivity of the technique by detecting corrosion product inside the insulation which is more reliable indicator of CUI progression
Effects of introgressed 4Nv Aegilops ventricosa chromosome on yield and yield components in bread wheat.
Effects of introgressed 4Nv Aegilops ventricosa chromosome on yield and yield components in bread whea
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The Italian Literature of the Axis War: Memories of Self-Absolution and the Quest for Responsibility by Guido Bartolini, Basingstoke, Palgrave Macmillan, 2021, xii + 263 pp., £74.99 (hardback), ISBN 9783030631802
Book review.Does it make sense to study the Italian literature of the Axis War – the military campaigns fascist Italy fought between 1940 and 1943 – and its influence on Italy's self-absolving discourses almost 80 years after the end of the conflict and the fall of the regime? What may seem a rhetorical question in fact reflects a current debate in Italy following the new far-right government's attempt to set aside the Resistance component from the 2023 annual 25 April Liberation Day commemoration in the name of a ‘restored national harmony’, or the fact that the largest European conflict since the Second World War is currently being fought in Ukraine in the name of – according to the official Russian rhetoric – the ‘denazification’ of a country led by a ‘Jewish president’. In view of this new wave of historical revisionism and attempts to rewrite (or abuse) history, Guido Bartolini's book is a timely and analytical attempt to explore and understand the role played by postwar Italian literature in the startling marginalisation of the memory of Italy's participation in the Axis War and its crimes
Optimal topology seletion for 2D structures with stress constraints via Smooth Evolutionary Structural Optimization
O artigo aborda a otimização topológica em problemas de elasticidade plana linear considerando a minimização do volume com restrição de tensão e empregando um índice de desempenho como monitoramento para o encontro da região de ótimo. Utiliza‐se para este fim o método clássico da otimização evolucionária estrutural, ou Evolutionary Structural Optimization (ESO). Este procedimento de otimização baseia‐se na retirada sistemática e gradativa dos elementos com menores tensões em comparação com a tensão máxima da estrutura. Procedimento este também conhecido como um processo «hard‐kill». Propõe‐se neste trabalho uma variante do método ESO, denominado de Smoothing ESO (SESO), cuja filosofia baseou‐se na observação de que se o elemento não for realmente necessário à estrutura, naturalmente sua contribuição de rigidez vai diminuindo progressivamente, até que ele não tenha mais influência. Isto é, sua remoção é feita de forma suave, atenuando os valores da matriz constitutiva do elemento, como se este estivesse em processo de danificação. Define‐se também o índice de desempenho para o monitoramento deste processo evolucionário suavizado. As aplicações do ESO e do SESO são feitas com o método dos elementos finitos, mas considerando um elemento finito triangular e de alta ordem. Por fim, implementou‐se um filtro espacial em termos de controle de tensão, o qual associado à técnica SESO se mostrou ser bastante estável e eficiente na eliminação da formação do tabuleiro.This paper approaches the topology optimization problems in plane linear elasticity considering the minimization of the volume with restriction of the stress employing an index of performance for monitoring the meeting of the optimum region. It is used for this purpose the classical evolutionary structural optimization, or ESO ‐ evolutionary structural optimization. This procedure is based on systematic and gradual removal of the elements with lower stress compared with the maximum stress of the structure. This procedure also known as a process “hard‐kill”. It is proposed a variant of the ESO method, called SESO ‐ Smoothing ESO, which is based on the philosophy that if an element is not really necessary for the structure, its contribution to the structural stiffness will gradually diminish until it has no longer influence in the structure, so its removal is performed smoothly. That is, their removal is done smoothly, reducing the values of the constitutive matrix of the element as if it were in the process of damage. A new performance index for the monitoring of this evolutionary process smoothed is proposed herein. The applications of ESO and SESO are made with the finite element method, but considering a high order triangular element based on the free formulation. Finally, it is implemented a spatial filter in terms of stress control, which was associated with SESO technique proved to be very stable and efficient in eliminating the formation of the checkerboard.Peer Reviewe
Biofilm inhibition of Inula viscosa (L.) Aiton and Globularia alypum L. extracts against Candida infectious pathogens and In vivo action on galleria mellonella model
The increasing importance of fungal infections has fueled the search for new beneficial alternatives substance from plant extracts. The current study investigates the antifungal and antibiofilm activity of Inula viscosa (L.) Aiton and Globularia alypum (L.) leaves extracts against Candida both in vitro and in vivo. The inhibition of planktonic and sessile Candida albicans and Candida glabrata growth using both leaf extracts are evaluated. Moreover; an in vivo infection model using Galleria mellonella larvae; infected and treated with the extracts are performed. All extracts show fungicidal activity; with a minimum fungicidal concentration (MFC) ranging from 128 to 512 mu g mL(-1) against the two selected strains of Candida. In particular, the best results are obtained with methanolic extract ofI. viscosa and G. alypum with an MFC value of 128 mu g mL(-1). The extracts are capable to prevent 90% of biofilm development at minor concentrations ranging from 100.71 +/- 2.49 mu g mL(-1) to 380.4 +/- 0.92 mu g mL(-1). In vivo, tests on Galleria mellonella larvae show that the extracts increase the survival of the larvae infected with Candida. The attained results reveal that I. viscosa and G. alypum extracts may be considered as new antifungal agents and biofilm inhibiting agents for the pharmaceutical and agro-food field
Guided Wave Tomography of Pipe Bends
Detection and monitoring of corrosion and erosion damage in pipe bends are open challenges due to the curvature of the elbow, the complex morphology of these defects, and their unpredictable location. Combining model based inversion with guided ultrasonic waves propagating along the elbow and inside its walls, offers the possibility of mapping wall-thickness losses over the entire bend and from a few permanently installed transducers under the realm of guided wave tomography (GWT). This paper provides the first experimental demonstration of GWT of pipe bends based on a novel curved ray tomography algorithm and an optimal transducer configuration consisting of two ring arrays mounted at the ends of the elbow and a line of transducers fixed to the elbow extrados. Using realistic, localized corrosion defects it is shown that detection of both the presence and progression of damage can be achieved with 100% sensitivity regardless of damage position around the bend. Importantly, this is possible for defects as shallow as 0.50% of wall thickness (WT) and for maximum depth increments of just 0.25% of WT. However, due to the highly irregular profile of corrosion defects, GWT generally underestimates maximum depth relative to the values obtained from 3-D laser scans of the same defects, leading in many cases to errors between 4 and 8% of WT
Evaluation of immunization practices in Naples, Italy.
This paper reports the results of a survey on vaccination coverage among children born in January 1995 and residing at the beginning of the study (March 1998) in the city of Naples, Italy. The percentages vaccinated, at various times from birth, with oral polio vaccine (OPV), have been compared with those found in a similar survey conducted at the end of 1985 regarding the cohort of children born in June 1983. By the fourth month of life 67% of the 1995 cohort were vaccinated with the first doses of OPV, an increase of about 26% on that found in the 1983 cohort. Similar results were found with the second doses. Among the 1995 cohort 49% were vaccinated with the third dose of OPV within the thirteenth month of life; the corresponding value for the 1983 cohort was 33%. Within the twenty-fourth month of life, in the 1995 cohort, 86% completed the primary cycle of vaccination with OPV; the corresponding figure for the 1983 cohort was 65%. At the end of the third year of life 80% of the 1995 cohort received the fourth dose of OPV. A significant association has been found between socioeconomic status and coverage level
Successful Coronary Stent Retrieval From a Pedal Artery
The purpose of this article is to report complications
from a coronary drug-eluting stent lost in the
peripheral circulation. We report the case of successful
retrieval of a sirolimus coronary stent from a pedal artery in
a young patient who underwent coronary angiography for
previous anterior myocardial infarction. Recognition of
stent embolization requires adequate removal of the device
to avoid unwelcome clinical sequelae.
Keywords Coronary stent Microsnare technique
Peripheral embolization Stent retrieva
Boundary flows in minimal models
We discuss in this paper the behaviour of minimal models of conformal theory
perturbed by the operator at the boundary. Using the RSOS
restriction of the sine-Gordon model, adapted to the boundary problem, a series
of boundary flows between different set of conformally invariant boundary
conditions are described. Generalizing the "staircase" phenomenon discovered by
Al. Zamolodchikov, we find that an analytic continuation of the boundary
sinh-Gordon model provides a flow interpolation not only between all minimal
models in the bulk, but also between their possible conformal boundary
conditions. In the particular case where the bulk sinh-Gordon coupling is
turned to zero, we obtain a boundary roaming trajectory in the theory
that interpolates between all the possible spin Kondo models.Comment: 13pgs, harvmac, 2 fig
Innovative nanomaterials for fuel cells fed with biogas
Challenges on sustainability promote research policy focused on renewable-energy technology development in order to enhance global energy security, local energy independence, environmental protection and economic growth. Biomass resources offer renewable energies that can play a key role in the current global strategies for reducing greenhouse gas emissions by partially replacing fossil fuels. The conversion of biomass chemical energy into electrical energy and cogenerated heat can be obtained by fuel cells. In particular, molten carbonate fuel cell (MCFC)
is the most suitable device for bioenergy production because it can be fed directly with biogas, whose primary constituents all improve the performance of the cell.
However hydrogen sulfide, which is the main biogas impurity, poisons the traditional nickel based anode, affecting the power and the endurance of the cell. In order to overcome this problem, an innovative anode material that resists against the sulfide corrosions has been developed. This material, made of a nanostructured and porous nickel support covered with a thin layer of ceria, exhibits high sulfur tolerance and recovering capability
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