Intermediate Debonding in Frp Strengthened RC Beams: a Numerical Model

One of the most effective ways for improving the flexural strength of RC members consists in bonding FRP laminates at their soffit in order to upgrade the existing tensile strength. Strengthening RC beams by Externally Bonded FRP laminates is getting more and more common and various Codes of Standards have been issued in Europe, United States and Japan. In particular, the most up-to-date document has been released in Italy one year ago. A key problem to be faced when managing FRP strengthened beams deals with the possible premature failure due to debonding between the adhesive layer and concrete, which can occur at the beam end (end debonding) or in the cracked zone (intermediate debonding). In the present paper, a mechanical model considering non-linear stress-strain relationships for concrete, steel and FRP-to-concrete interface is presented, with the aim of simulating the behavior of RC beams strengthened by externally bonded FRP plates

Evidence of a new low field cross-over in the vortex critical velocity of type-II superconducting thin films

We measure current-voltage characteristics as function of magnetic field and temperature in Nb strips of different thickness and width. The instability voltage of the flux flow state related to the vortex critical velocity v* is studied and compared with the Larkin-Ovchinnikov theory. Beside the usual power-law dependence v* ~ B^-1/2, in the low field range a new cross-over field, Bcr1, is observed below which v* decreases by further lowering the external magnetic field B. We ascribe this unexpected cross-over to vortex channeling due to a fan-like penetration of the applied magnetic field as confirmed by magneto-optic imaging. The observation of Bcr1 becomes a direct evidence of a general feature in type-II superconducting films at low fields, that is a channel-like vortex motion induced by the inhomogeneous magnetic state caused by the relatively strong pinning

The Early Bronze Age II City-Gate at Khirbet al-Batrawy, Jordan

Rapporto sui risultati degli scavi a Khirbet al-BatrawyReport on the results of the excavations at Khirbet al-Batraw

GDM-complicated pregnancies: focus on adipokines

Gestational diabetes mellitus (GDM) is a serious complication of pregnancy and is defined as a state of glucose intolerance that is first diagnosed and arises during gestation. Although the pathophysiology of GDM has not yet been thoroughly clarified, insulin resistance and pancreatic β-cell dysfunction are considered critical components of its etiopathogenesis. To sustain fetus growth and guarantee mother health, many significant changes in maternal metabolism are required in normal and high-risk pregnancy accompanied by potential complications. Adipokines, adipose tissue-derived hormones, are proteins with pleiotropic functions including a strong metabolic influence in physiological conditions and during pregnancy too. A growing number of studies suggest that various adipokines including adiponectin, leptin, visfatin, resistin and tumor necrosis factor α (TNF-α) are dysregulated in GDM and might have pathological significance and a prognostic value in this pregnancy disorder. In this review, we will focus on the current knowledge on the role that the aforementioned adipokines play in the development and progression of GDM.Gestational diabetes mellitus (GDM) is a serious complication of pregnancy and is defined as a state of glucose intolerance that is first diagnosed and arises during gestation. Although the pathophysiology of GDM has not yet been thoroughly clarified, insulin resistance and pancreatic β-cell dysfunction are considered critical components of its etiopathogenesis. To sustain fetus growth and guarantee mother health, many significant changes in maternal metabolism are required in normal and high-risk pregnancy accompanied by potential complications. Adipokines, adipose tissue-derived hormones, are proteins with pleiotropic functions including a strong metabolic influence in physiological conditions and during pregnancy too. A growing number of studies suggest that various adipokines including adiponectin, leptin, visfatin, resistin and tumor necrosis factor α (TNF-α) are dysregulated in GDM and might have pathological significance and a prognostic value in this pregnancy disorder. In this review, we will focus on the current knowledge on the role that the aforementioned adipokines play in the development and progression of GDM

Screening of high risk infants for metabolic disease in a metropolitan hospital

Screening of symptomatic infants for metabolic diseases is described which led to an improved detection rate because of better awareness and case selection, as well as the use of a test for urinary organic acids.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147121/1/jimd0081.pd

Intermittent turbulent dynamo at very low and high magnetic Prandtl numbers

Context: Direct numerical simulations have shown that the dynamo is efficient even at low Prandtl numbers, i.e., the critical magnetic Reynolds number Rm_c necessary for the dynamo to be efficient becomes smaller than the hydrodynamic Reynolds number Re when Re -> infinity. Aims: We test the conjecture (Iskakov et al. 2007) that Rm_c actually tends to a finite value when Re -> infinity, and we study the behavior of the dynamo growth factor \gamma\ at very low and high magnetic Prandtl numbers. Methods: We use local and nonlocal shell-models of magnetohydrodynamic (MHD) turbulence with parameters covering a much wider range of Reynolds numbers than direct numerical simulations, but of astrophysical relevance. Results: We confirm that Rm_c tends to a finite value when Re -> infinity. The limit for Rm -> infinity of the dynamo growth factor \gamma\ in the kinematic regime behaves like Re^\beta, and, similarly, the limit for Re -> infinity of \gamma\ behaves like Rm^{\beta'}, with \beta=\beta'=0.4. Conclusion: Comparison with a phenomenology based on an intermittent small-scale turbulent dynamo, together with the differences between the growth rates in the different local and nonlocal models, indicate a weak contribution of nonlocal terms to the dynamo effect.Comment: 5 pages, 6 figure

Efficiency of CFRP NSM strips and EBR laminates for flexural strengthening of RC beams

The efficiency of Fiber Reinforced Polymer (FRP) materials for strengthening existing Reinforced Concrete (RC) structures according to the Near Surface Mounted (NSM) technique can be greater than the External Bonded Reinforcement (EBR) technique since the tensile strength of the FRP materials is in general better exploited. Firstly, this paper deals with analyzing the effect of the loading pattern on RC beams strengthened with both types of strengthening technique; in particular, two loading patterns have been used for the experimental tests on simple supported beams: 1) a four points bending scheme, and 2) a scheme with distributed loads, in order to check the sensitivity of failure modes and ultimate loads to different distributions of bending moment and shear along the beam. Then, a comparison between the results of flexural tests on RC beams strengthened with both NSM and EBR techniques is dealt with

Evaluation of systematic review utilization in the development of OB-GYN randomized controlled trials

Introduction: The issue of research waste has been raised due to the fact that 85% of funding for biomedical research has been improperly utilized. A prominent issue is the frequency of randomized controlled trials (RCTs) being conducted without prior consultation of existing support, such as systematic reviews (SRs). Meticulous monitoring is necessary to ensure that clinical recommendations are being made with confidence in high-quality biomedical practices. The aim of this study was to survey Obstetric and Gynecology journals to analyze their published articles for citation of SR for justification of conducting the RCT.Methods: We conducted a search of PubMed for RCTs published between January 1, 2014 and December 31, 2017, in the top ten Obstetric and Gynecology journals. Each included study was evaluated to determine the number of SRs cited within the introduction, methods, and discussion sections. We further analyzed whether the SR was cited verbatim or indirectly, number of participants, type of intervention being studied, funding source, type of trial, and how the outcome was perceived.Results: Of the 720 articles from our initial search, 458 (63.61%) met inclusion criteria. Of the 458 included studies, 279 (60.92%) cited an SR in the introduction, 34 (7.42%) cited an SR in the methods, and 207 (45.2%) cited an SR in the discussion as justification for conducting the study.Conclusion: A large portion of the RCTs being published in clinical Obstetrics and Gynecology journals are not citing SRs as justification for conducting their studies, which may be leading to an increase in research waste

Transient numerical assessment of race car dry-sump oil under different maneuvers

A numerical assessment of a dry-sump oil system was performed by Computational Fluid Dynamics (CFD). Unlike conventional cars, race cars are subjected to high accelerations that induce oil sloshing. Hence, dry-sump oil systems are required to collect the oil outside of the engine prior to be pumped inside of it again. To avoid engine malfunctions, the dry-sump must guarantee continuously oil suction in every maneuver. To perform such simulations, the model was subjected to different car maneuvers extracted from data acquisition available from real race car, showing that single and combined maneuvers, such as acceleration, braking and turnings can induce downward, upward and lateral accelerations higher than 2g during several seconds. Therefore, four different single maneuvers (acceleration, deceleration, turn right and turn left) as well as a set of contaminated maneuvers (braking and turning) were studied. Simulations were achieved by mean of the Volume of Fluid Method (VOF) for a air-oil system. The influence of the turbulence modeling was also investigated. First a forerunner design was analyzed and both the race car tests and CFD simulations showed that for the most extreme maneuvers (pure braking and combined with braking with turning right) the original design failed before the end of the maneuvers by air suction in the pump inlet. In consequence, the dry-sump was redesigned and assessed under these extreme conditions until to ensure stable oil aspiration.Publicado en: Mecánica Computacional vol. XXXV, no. 7.Facultad de Ingenierí