Optimizing Mechanical and Electrical Performance of SWCNTs/FeO Epoxy Nanocomposites: The Role of Filler Concentration and Alignment.

The demand for polymer composites with improved mechanical and electrical properties is crucial for advanced aerospace, electronics, and energy storage applications. Single-walled carbon nanotubes (SWCNTs) and iron oxide (FeO) nanoparticles are key fillers that enhance these properties, yet challenges like orientation, uniform dispersion, and agglomeration must be addressed to realize their full potential. This study focuses on developing SWCNTs/FeO epoxy composites by keeping the SWCNT concentration constant at 0.

A Numerical Model to Predict the Relaxation Phenomena in Thermoset Polymers and Their Effects on Residual Stress during Curing, Part II: Numerical Evaluation of Residual Stress.

This article proposes a numerical routine to predict the residual stresses developing in an epoxy component during its curing. The scaling of viscoelastic properties with the temperature and the degree of conversion is modeled, adopting a mathematical formulation that considers the concurrent effects of curing and structural relaxation on the epoxy's viscoelastic relaxation time. The procedure comprises two moduli: at first, the thermal-kinetical problem is solved using the thermal module of Ansys and a homemade routine written in APDL, then the results in terms of temperature and the degree of conversion profiles are used to evaluate the viscoelastic functions, and the structural problem is solved in the mechanical module of Ansys, allowing the residual stresses calculation.

A Numerical Model to Predict the Relaxation Phenomena in Thermoset Polymers and Their Effects on Residual Stress during Curing-Part I: A Theoretical Formulation and Numerical Evaluation of Relaxation Phenomena.

This paper analyzes the effect of crosslinking reactions on a thermoset polymer's viscoelastic properties. In particular, a numerical model to predict the evolution of epoxy's mechanical properties during the curing process is proposed and implemented in an Ansys APDL environment. A linear viscoelastic behavior is assumed, and the scaling of viscoelastic properties in terms of the temperature and degree of conversion is modeled using a modified version of the TNM (Tool-Narayanaswamy-Mohynian) model.

Anterior gastric wall anastomosis may lead to lower rate of delayed gastric emptying after minimally invasive Ivor Lewis esophagectomy: a retrospective cohort study.

Introduction: In minimally invasive esophagectomy, a circular stapled anastomosis is common, but no evidence exists investigating the role of the specific localization of the anastomosis. The aim of this study is to evaluate the impact of an esophagogastrostomy on the anterior or posterior wall of the gastric conduit on the postoperative outcomes.

Material And Methods: All oncologic minimally invasive Ivor Lewis procedures, performed between 2017 and 2022, were included in this study.

Mosses on Geopolymers: Preliminary Durability Study and Chemical Characterization of Metakaolin-Based Geopolymers Filled with Wood Ash.

Burning wood is estimated to produce about 6-10% of ash. Despite the possibility of recycling wood ash (WA), approximately 70% of the wood ash generated is landfilled, causing costs as well as environmental pollution. This study aims to recycle WA in an alternative way by inserting it as filler in geopolymeric materials.

New Materials and Technologies for Durability and Conservation of Building Heritage.

The increase in concrete structures' durability is a milestone to improve the sustainability of buildings and infrastructures. In order to ensure a prolonged service life, it is necessary to detect the deterioration of materials by means of monitoring systems aimed at evaluating not only the penetration of aggressive substances into concrete but also the corrosion of carbon-steel reinforcement. Therefore, proper data collection makes it possible to plan suitable restoration works which can be carried out with traditional or innovative techniques and materials.

Fabrication of High-Performance CNT Reinforced Polymer Composite for Additive Manufacturing by Phase Inversion Technique.

Additive Manufacturing (AM) of polymer composites has enabled the fabrication of highly customized parts with notably mechanical properties, thermal and electrical conductivity compared to un-reinforced polymers. Employing the reinforcements was a key factor in improving the properties of polymers after being 3D printed. However, almost all the existing 3D printing methods could make the most of disparate fiber reinforcement techniques, the fused filament fabrication (FFF) method is reviewed in this study to better understand its flexibility to employ for the proposed novel method.

Comparative Study of Phenomenological Residual Strength Models for Composite Materials Subjected to Fatigue: Predictions at Constant Amplitude (CA) Loading.

The most popular methods of characterizing a composite's fatigue properties and predicting its life are phenomenological, meaning the micro-mechanisms of composite structures under cyclic loading are not treated. In addition, in order to characterize the fatigue properties, only macro-parameters, namely strength and/or stiffness, are adopted. Residual strength models are mostly used in practice, given their strong relationship with safety and reliability.

Principal Features of Fatigue and Residual Strength of Composite Materials Subjected to Constant Amplitude (CA) Loading.

This paper summarizes the principal features of composites' responses when subjected to constant amplitude (CA) cyclic loadings. The stochastic nature of the responses; the absence of a detectable fatigue limit; the sudden drop of strength; the general validity of the strength-life equal-rank assumption (SLERA); and, ultimately, the residual strength-life equal-rank assumption (RSLERA) are discussed on the basis of the selected experimental data available in literature. The objective is defining a robust test in order to ascertain the reliability of the phenomenological models.

Constitutive law describing the phenomenology of subyield mechanically stimulated glasses.

The principal features of the volumetric as well as the viscoelastic response of mechanically stimulated glasses can be summarized as follows: (i) the time-aging time shift factors contract upon increasing the probe stress (i.e., the stress apparently modifies the volume recovery kinetics), (ii) the volume recovery baseline remains unaltered (i.