Field Retrofit and Testing of a Corroded Metal Culvert Using GFRP

One of the current pressing problem for all DOTs is the corrosion-oriented deterioration of the existing metal culverts. These metal culverts typically are designed for a life of 50 years. However, corrosion is making them last no longer than 30years. Here we propose use of Glass Fiber Reinforced Polymers (GFRP) pipe section as a fit-in GFRP profile liner for complete repair and rehabilitation of the corroded metal culvert with an expected life of 75 years. This is mainly because of the corrosion free nature of the GFRP material. In the current study, the design method for using glass fiber-reinforced polymer (GFRP) slip liner to retrofit CMP culvert is presented. Furthermore, this report presents field implementation of retrofitting of a 24 in corroded corrugated metal pipe embedded that is 25 ft span and buried below 18 of soil. The corroded corrugated metal pipe was retrofitted with a 22 in diameter GFRP slip liner. Load testing before and after the retrofitting proves the efficiency of the proposed retrofitting system and its ability to extend the service life of the retrofitted pipe

The Significance of Multi-Size Carbon Fibers on the Mechanical and Fracture Characteristics of Fiber Reinforced Cement Composites

One of the main challenges of using a high fiber volume content in a cement composite is the narrow margin of fiber volume content beyond which fibers can cause an adverse effect on the mechanical properties. In this paper, the significance of fiber size distribution and fiber volume content of different proportions of chopped and milled carbon microfibers are investigated. The mixes’ flowability showed improvement with altering the fiber size distribution despite having a high fiber content. Uniaxial compression cylinders and unnotched and notched beams were cast and then tested at 7 and 28 days of age. It was found that the compressive strength is significantly affected by fiber size distribution more than fiber volume content. On the other hand, the modulus of rupture and fracture toughness are proportional to the fiber volume content with little effect of fiber size distribution. Finally, neither high fiber volume content nor altered fiber size distribution significantly affected the elastic modulus of the fiber cement composites

The development of a simplified modeling technique for the finite element analysis of reinforced masonry shear walls

Reinforced masonry shear walls are structural elements that are commonly used in construction. It is important to properly model their contribution to the strength and stiffness of the structures in which they appear. Analysts typically represent these shear walls with deep beam elements within building models. However, the assumption that a shear wall behaves as a deep beam breaks down when shear failure occurs, and cracking starts to dominate the behavior of the wall. There is a need to develop a finite element model of these shear walls that is accurate but simple enough to be included as a part of a full building model. A 2-D masonry shear wall model was developed to meet these requirements. To make it applicable within standard structural analysis software, the model does not require a detailed representation of each component of the wall separately. Instead, the reinforcing is smeared and overlaid with a plane stress masonry element. Plasticity is assumed for the steel and cracking/damage is assumed for the masonry. Reductions in masonry stiffness were applied to account for initial cracks, and artificial damping was added to stabilize the solution process after the occurrence of masonry damage. Data from two experimental test programs were used to verify the proposed modeling technique along with comparisons with detailed finite element models. It was found that the behavior of the simplified models was quite close to that of the detailed finite element models for all cases considered. When compared to the peak values of cyclic load of the experimental specimens, it was found that initial stiffness, peak load, and displacement at final failure were well predicted although, for short shear walls which are dominated by shear failure of the masonry, damage did not evolve as rapidly in the finite element models as was observed in the experimental specimens. The proposed modeling technique was therefore shown to reasonably predict reinforced masonry shear wall behavior, even with coarse meshing and smeared steel reinforcement, regardless of the wall aspect ratio, amount of axial vertical load applied to the wall, and reinforcement ratio

A cysteine sensor based on a gold nanoparticle–iron phthalocyanine modified graphite paste electrode

An electrochemical sensor for the sensitive and selective detection of cysteine is proposed based on a gold nanoparticle (AuNP)–iron(III) phthalocyanine (FePc) modified graphite paste electrode. The sensor was characterised using scanning electron microscopy (SEM/EDX), transmission electron microscopy (TEM), cyclic voltammetry and electrochemical impedance spectroscopy (EIS). Cyclic voltammetry studies demonstrated that the electrochemical behaviour of cysteine at the AuNP–FePc modified graphite paste electrode is considerably improved compared to both the blank (unmodified) and FePc-modified graphite paste electrodes. The enhancement of the anodic redox signal for cysteine was due to a catalytic effect of gold nanoparticles which was investigated using three different graphite paste electrodes − 0.02, 0.055 and 0.11 wt% Au nanoparticles, each with a fixed quantity of FePc (5 wt%). The sensor fabricated using 0.055 wt% AuNPs exhibited optimum sensitivity as examined via differential pulse voltammetry measurements with an analytical range of 50–1000 μM and a LOD of 0.27 μM. The sensor was utilised for the determination of cysteine in pharmaceutical preparations

The Significance of Multi-Size Carbon Fibers on the Mechanical and Fracture Characteristics of Fiber Reinforced Cement Composites

One of the main challenges of using a high fiber volume content in a cement composite is the narrow margin of fiber volume content beyond which fibers can cause an adverse effect on the mechanical properties. In this paper, the significance of fiber size distribution and fiber volume content of different proportions of chopped and milled carbon microfibers are investigated. The mixes’ flowability showed improvement with altering the fiber size distribution despite having a high fiber content. Uniaxial compression cylinders and unnotched and notched beams were cast and then tested at 7 and 28 days of age. It was found that the compressive strength is significantly affected by fiber size distribution more than fiber volume content. On the other hand, the modulus of rupture and fracture toughness are proportional to the fiber volume content with little effect of fiber size distribution. Finally, neither high fiber volume content nor altered fiber size distribution significantly affected the elastic modulus of the fiber cement composites

Active principle from Moringa oleifera Lam leaves effective against two leukemias and a hepatocarcinoma

Medicinal plants are important elements of indigenous medical system that have persisted in developing countries. Many of the pharmacological principles currently used as anticancer agents were first isolated from plants. However, some important anticancer agents are still extracted from plants because they cannot be synthesized chemically on a commercial scale due to their complex structures that often contain several chiral centers. The aim of this study was to test different extracts from the leaves of Moringa or drumstick tree (Moringa oleifera) for activity against leukemia and hepatocarcinoma cells in vitro. The extracts could kill majority (70 - 86%) of the abnormal cells among primary cells harvested from 10 patients with acute lymphoblastic leukemia (ALL) and 15 with acute myeloid leukemia (AML) as well as a culture of hepatocarcinoma cells (75% death), but most significantly by the hot water and ethanol extracts. In conclusion, M. oleifera may have potential for use as source of natural treatment for diseases such as cancer.Key words: Moringa oleifera, anti-cancer, acute lymphoblastic leukemia, acute myeloid leukemia, hepatocarcinoma

Bearing Fault Diagnosis Using Lightweight and Robust One-Dimensional Convolution Neural Network in the Frequency Domain

The massive environmental noise interference and insufficient effective sample degradation data of the intelligent fault diagnosis performance methods pose an extremely concerning issue. Realising the challenge of developing a facile and straightforward model that resolves these problems, this study proposed the One-Dimensional Convolutional Neural Network (1D-CNN) based on frequency-domain signal processing. The Fast Fourier Transform (FFT) analysis is initially utilised to transform the signals from the time domain to the frequency domain; the data was represented using a phasor notation, which separates magnitude and phase and then fed to the 1D-CNN. Subsequently, the model is trained with White Gaussian Noise (WGN) to improve its robustness and resilience to noise. Based on the findings, the proposed model successfully achieved 100% classification accuracy from clean signals and simultaneously achieved considerable robustness to noise and exceptional domain adaptation ability. The diagnosis accuracy retained up to 97.37%, which was higher than the accuracy of the CNN without training under noisy conditions at only 43.75%. Furthermore, the model achieved an accuracy of up to 98.1% under different working conditions, which was superior to other reported models. In addition, the proposed model outperformed the state-of-art methods as the Signal-to-Noise Ratio (SNR) was lowered to −10 dB achieving 97.37% accuracy. In short, the proposed 1D-CNN model is a promising effective rolling bearing fault diagnosis