Search results for "Confined"
showing 10 items of 65 documents
M8_Microfluidics_for_CNT
2018
A comparation of two sorting strategies. While the shallow channel guides the droplets more precisely to the sorting point, the confined droplets are more vulnerable to coalescence and break-up. The deep channel lowers the positioning precision, however, the droplets are more stable.
Metabolic Impacts of Confinement during the COVID-19 Pandemic Due to Modified Diet and Physical Activity Habits
2020
While the detrimental effects of a chronic positive energy balance due to a sedentary lifestyle have been well established, the impacts of a short period of abruptly reduced physical activity and overeating arising from strict confinement due to the COVID-19 pandemic will soon start to emerge. To reasonably anticipate major consequences according to the available evidence, we hereby review the literature for studies that have explored the health impacts of several weeks of a reduction in physical activity and daily step-count combined with modified eating habits. These studies identify as main metabolic consequences increases in insulin resistance, total body fat, abdominal fat and inflamma…
Monte Carlo simulation of block copolymers
2000
Monte Carlo simulations deal with crudely simplified but well-defined models and have the advantage that they treat the statistical thermodynamics of the considered model exactly (apart from statistical errors and problems due to finite size effects). Therefore, these simulations are well suited to test various approximate theories of block copolymer ordering, e.g. the self-consistent field theory. Recent examples of this approach include the study of block copolymer ordering at melt surfaces and confinement effects in thin films, adsorption of block copolymers at interfaces of unmixed homopolymer blends, the phase behavior of ternary mixtures of two homopolymers and their block copolymer, …
Stress-strain models for normal and high strength confined concrete: Test and comparison of literature models reliability in reproducing experimental…
2017
SUMMARY: The adoption of proper constitutive laws for confined concrete is basic for seismic assessment of new and existing reinforced concrete civil structures. The deformation capacity of reinforced concrete (RC) columns subjected to axially centred and eccentric loads depends on the effectiveness confinement action. A proper assignment of the stressstrainlaws for concrete allows obtaining an adequate definition of the ductility of the crosssections and correctly identifying mechanical nonlinearities in computational models.Several studies concerning the behaviour of confined concrete have been carried out, highlighting the role of different geometrical and mechanical parameters to the ov…
Strength and ductility of confined concrete columns under axial load and biaxial bending
2012
The behaviour of prismatic reinforced concrete columns under increasing eccentric compression load was experimentally investigated and analytically modelled. Columns with distributed longitudinal reinforcement and closely spaced transverse reinforcement were tested up to failure, considering different values and directions of eccentricity. Preliminary tests were carried out under concentric compression in order to validate the choice of the stress-strain laws adopted for the confined concrete and the longitudinal steel bars in compression. In the paper, closed form expressions able to approximate the experimental results in the case of uniaxial bending are presented. Finally, a fibre numeri…
COMPRESSIVE BEHAVIOR OF CONCRETE COLUMNS AXIALLYLOADED BEFORE CFRP-WRAPPING. REMARKS BY EXPERIMENTALNUMERICAL INVESTIGATION
2018
Strengthening of existing concrete columns with Fiber Reinforced Polymers (FRP) results generally in a satisfactory structural member improvement in terms of load and strain capacity. A reliable prediction of the capacity obtained by these reinforcement strategies requests a proper knowledge of the load-strain response of the confined concrete elements. However, so far, the available design methods and technical codes do not consider the effect of the possible presence of service loads at the moment of application of the reinforcement, and therefore, the compressive behavior of the concrete confined under preload is still unclear. In this paper, the effect of sustained loads on the compress…
Assessment of the load carrying capacity of reinforced concrete columns strengthened by steel cages Specificità nella valutazione della capacità port…
2018
In the present paper, a selected review of the most relevant analytical models provided for the evaluation of the con-finement properties of Steel Jacketed RC columns is discussed. The reliability of the models is tested by comparing the analytical predictions of the load capacity with experimental results available in the literature depending on the type of mechanical end-connections. Moreover, new considerations regarding the application of the steel jacketing on columns while loaded are faced by experimental investigation
FE modeling of Partially Steel-Jacketed (PSJ) RC columns using CDP model
2018
This paper deepens the finite element modeling (FEM) method to reproduce the compressive behavior of partially steel-jacketed (PSJ) RC columns by means of the Concrete Damaged Plasticity (CDP) Model available in ABAQUS software. Although the efficiency of the CDP model is widely proven for reinforced concrete columns at low confining pressure, when the confinement level becomes high the standard plasticity parameters may not be suitable to obtain reliable results. This paper deals with these limitations and presents an analytically based strategy to fix the parameters of the Concrete Damaged Plasticity (CDP) model. Focusing on a realistic prediction of load-bearing capacity of PSJ RC column…
Simulating CFRP-confinement of concrete bridge piers under sustained loads: evaluation of the compressive capacity
2018
The present paper deals with the evaluation of the compressive behaviour of circular concrete columns strengthened with carbon fiber reinforced polymers (CFRP) under different levels of sustained loads and subsequently loaded until failure. The aim was to compare the effect of existing stress/strain states on the axial load-strain response of bridge piers after strengthening under sustained loads. An experimental investigation was carried out on circular plain concrete columns loaded up to low, medium and high ratios of the concrete compression capacity before the application of the CFRP-confinement. After the strengthening process, the columns were loaded until failure, comparing the resul…
Do we understand the solid-like elastic properties of confined liquids?
2021
Recently, in polymeric liquids, unexpected solid-like shear elasticity has been discovered, which gave rise to a controversial discussion about its origin (1⇓–3). The observed solid-like shear modulus G depends strongly on the distance L between the plates of the rheometer according to a power law G ∝ L − p with a nonuniversal exponent ranging between p = 2 and p = 3 . Zaccone and Trachenko (4) have published an article in which they claim to explain these findings by a nonaffine contribution to the liquid shear modulus. The latter is represented as Δ G ∝ − ∑ λ = L , T 1 V … [↵][1]1To whom correspondence may be addressed. Email: giancarlo.ruocco{at}roma1.infn.it. [1]: #xref-corresp-1-1