Hybrid Reinforced Magnesium Matrix Composites (Mg/Sic/GNPs): Drilling Investigation

The machinability of graphene-reinforced magnesium-based hybrid nanocomposites produced through the application of powder metallurgy method has not been completely reported. This article presents an experimental investigation on the thrust force, the surface roughness (Ra), and drilled surfaces characteristics in the drilling process of a Mg/SiC/GNPs (magnesium matrix based silicon carbide and graphene nanoplatelets) hybrid magnesium matrix composite. The hybrid composite material was produced through the application of a powder metallurgy method. The experiments were carried out with uncoated, PVD (Physical Vapor Deposition), and CVD (Chemical Vapor Deposition) coated tungsten carbide drill bits at three levels of cutting speeds (30, 40, and 50 m/min), and three different levels of feed rate (0.10, 0.15, and 0.20 mm/rev) under dry machining conditions. Taguchi’s L27 (33) orthogonal array and S/N ratio were used to optimize the optimal parameters for thrust force and surface roughness. The experimental results indicated that the thrust force and the surface roughness were extremely dependent on a particular type of drill bits, feed rate, and cutting speed. The feed rate parameter is known to have a significant influence on the surface finish

Validation of risk analysis for ship collision in narrow waters by using fuzzy Bayesian networks approach

Risk analysis is regarded as one of the most critical research topics in maritime industry due to the nature of work. Validation of risk analysis is a significant challenge for safety researchers. This paper aims to address the gap by utilising the power of Bayesian Network method under fuzzy logic environment. While Bayesian Network provides a compact representation of a joint probability distribution, fuzzy logic tackles with vagueness and ambiguity in PRA (Probabilistic Risk Assessment). The validation and sensitivity analyses are performed under various conditions to improve the accuracy of findings. Three different axioms are tested to validate the results. The proposed method is applied for the risk modelling of ship collision in narrow waters. Besides its theoretical background, the paper is expected to help safety researchers validate their results. The maritime safety professionals (safety inspectors, DPAs, superintendents and ship owners) can also benefit from the paper to identify and minimise the potential risks for ship collision in narrow waters

Evolution of Microstructure, Mechanical Properties, and Corrosion Resistance of Mg–2.2Gd–2.2Zn–0.2Ca (wt%) Alloy by Extrusion at Various Temperatures

The current investigation involved casting the Mg–2.2Gd–2.2Zn–0.2Ca (wt%) alloy (GZX220) through permanent mold casting, followed by homogenization at 400 °C for 24 h and extrusion at 250 °C, 300 °C, 350 °C, and 400 °C. Microstructure investigations revealed that α-Mg, Mg–Gd, and Mg–Gd–Zn intermetallic phases were present in the as-cast alloy. Following the homogenization treatment, a majority of these intermetallic particles underwent partial dissolution into the matrix phase. α-Mg grains exhibited a considerable refinement by extrusion due to dynamic recrystallization (DRX). At low extrusion temperatures, higher basal texture intensities were observed. The mechanical properties were remarkably enhanced after the extrusion process. However, a consistent decline in strength was observed with the rise in extrusion temperature. The corrosion performance of the as-cast GZX220 alloy was reduced by homogenization because of the lack of corrosion barrier effect of secondary phases. A significant enhancement of corrosion resistance was achieved by the extrusion process

Prediction of human–machine interface (HMI) operational errors for maritime autonomous surface ships (MASS)

The human factor is a hot topic for the maritime industry since more than 80 percent of maritime accidents are due to human error. Minimizing human error contributions in maritime transportation is vital to enhance safety levels. At this point, the maritime autonomous surface ships (MASS) concept has become one of the most significant aspects to minimize human errors. The objective of this research is to predict the human–machine interface (HMI)-based operational errors in autonomous ships to improve safety control levels. At this point, the interaction between shore-based operator and controlling system (cockpits) can be monitored and potential HMI operational errors can be predicted. This research utilizes a Success Likelihood Index Method (SLIM) under an interval type-2 fuzzy sets (IT2FSs) approach. While the SLIM provides a prediction of the human–machine interface (HMI) operational errors, the IT2FSs tackles uncertainty and vagueness in the decision-making process. The findings of this paper are expected to highlight the importance of human–machine interface (HMI) operational errors in autonomous ships not only for designers but also for operational aspects

An extended human reliability analysing under fuzzy logic environment for ship navigation

© 2022 Informa UK Limited, trading as Taylor & Francis Group.Preparation for a sea voyage is one of the fundamental aspects of navigation. Several complexities are involved during the preparation of the ship for navigation due to the nature of maritime work. At this point, analysing human-related error is of paramount importance to ensure the safety of the ship and the crew. This paper describes the principles of a methodology, namely fuzzy-based shipboard operation human reliability analysis (SOHRA), to quantitatively perform human error assessment through procedures of preparing the ship for navigation. While the SOHRA (a marine-specific HRA approach) quantifies human error, the fuzzy logic deals with ambiguity and vagueness in the human error detection problem. The findings show that the total HEP (Human error probability) is found 1.49E-01 for preparing the ship for navigation. Consequently, the paper provides practical contributions to shore-based safety professionals, ship managers, and masters of the ship since it performs a systematic human reliability assessment and enhances safety control levels in the operational aspect

The role of serum interleukin-37 levels, inflammation and blood pressure in patients with preeclampsia

PubMed: 32476486Aim: Preeclampsia is one of the major causes of perinatal, fetal, and maternal mortality and morbidity. The aim of this study was to investigate the association of serum interleukin 37 (IL 37) with preeclampsia. Methods: 39 women with preeclampsia were included as the study group. 38 healthy, and normotensive pregnant women, at similar gestational week with similar gravidity volunteered as the control group. Clinical findings, biochemical parameters, maternal and perinatal outcomes, and the serum concentrations of IL37 were compared between the groups. The relationship of IL 37 concentrations with clinical findings and blood pressure outcomes were also investigated. Results: Maternal serum IL 37 concentrations were signi?cantly higher in patients with preeclampsia compared to the healthy pregnant women in the control group (p = .005). IL 37 positively correlated systolic blood pressure (BP) (r = 0.344, p = .002), and diastolic BP (r = 0.332, p = .003). IL 37 was identified as an independent predictor of preeclampsia. Conclusions: Serum IL 37 concentrations were higher in preeclamptic patients compared to healthy pregnant women. Furthermore, IL 37 concentrations achieved success in identifying preeclampsia with hypertension. Increased IL 37 activity may have a role in the pathophysiology of preeclampsia. © 2020, © 2020 Taylor & Francis.Recep Tayyip Erdogan University Scientific Research Committee sponsored our study

The role of serum interleukin-37 levels, inflammation and blood pressure in patients with preeclampsia

Aim Preeclampsia is one of the major causes of perinatal, fetal, and maternal mortality and morbidity. The aim of this study was to investigate the association of serum interleukin 37 (IL 37) with preeclampsia. Methods 39 women with preeclampsia were included as the study group. 38 healthy, and normotensive pregnant women, at similar gestational week with similar gravidity volunteered as the control group. Clinical findings, biochemical parameters, maternal and perinatal outcomes, and the serum concentrations of IL37 were compared between the groups. The relationship of IL 37 concentrations with clinical findings and blood pressure outcomes were also investigated. Results Maternal serum IL 37 concentrations were significantly higher in patients with preeclampsia compared to the healthy pregnant women in the control group (p = .005). IL 37 positively correlated systolic blood pressure (BP) (r = 0.344, p = .002), and diastolic BP (r = 0.332, p = .003). IL 37 was identified as an independent predictor of preeclampsia. Conclusions Serum IL 37 concentrations were higher in preeclamptic patients compared to healthy pregnant women. Furthermore, IL 37 concentrations achieved success in identifying preeclampsia with hypertension. Increased IL 37 activity may have a role in the pathophysiology of preeclampsia

Derivation And Validation Of A New Still Activity Score (Sas)

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