Esophageal perforation during cuffed tunneled catheter introduction: First case in literature

The percutaneous catheterization of central veins is increasingly used in nephrological practice as a temporary or permanent vascular access. Some mechanical complications may occur during insertion of catheter such as misplaced catheter. In this report, we present a case that was misplaced the catheter in esophagus and to analyze the reason of catheter malposition during percutaneous tunneled hemodialysis catheter insertion.     

Some new operations on single-valued neutrosophic matrices and their applications in multi-criteria group decision making

The single-valued neutrosophic set plays a crucial role to handle indeterminant and inconsistent information during decision making process. In recent research, a development in neutrosophic theory is emerged, called single-valued neutrosophic matrices, are used to address uncertainties. The beauty of single-valued neutrosophic matrices is that the utilizing of several fruitful operations in decision making. In this paper, some novel operations on neutrosophic matrices of are introduced, that is, type-1 product \((\tilde \odot )\), type-2 product \((\tilde \otimes )\) and minus \((\tilde \ominus )\) between two single-valued neutrosophic matrices. Also, we introduced complement, transpose, upper and lower α ?level matrices of single-valued neutrosophic matrices and discussed related properties. Furthermore, we propose a multi-criteria group decision making method based on these new operations, and give an application of the proposed method in a real life problem. Finally, we compare proposed method in this paper with proposed methods previously.     

Multicriteria Decision‐Making Method Based on Similarity Measures under Single‐Valued Neutrosophic Refined and Interval Neutrosophic Refined Environments

In this paper, we propose three similarity measure methods for single‐valued neutrosophic refined (SVNR) sets and interval neutrosophic refined (INR) sets based on Jaccard, Dice, and Cosine similarity measures of SVN‐sets and interval neutrosophic sets. Furthermore, we suggest two multicriteria decision‐making (MCDM) methods under SVNR environment and INR environment, and give applications of proposed MCDM methods. Finally, we suggest a consistency analysis method for proposed similarity measures between INR‐sets and give an application to demonstrate process of the method.     

Elastic–plastic thermal stress analysis in a thermoplastic composite disc applied linear temperature loads via FEM

The aim of this study is to obtain thermal stresses in a thermoplastic composite disc unidirectionally reinforced by steel fibers. Finite element method was used to calculate the thermal elastic and elastic–plastic stress distributions within the composite disc. Therefore, the solution was carried out using the ANSYS software. The temperature loading was chosen so as to vary linearly from inner surface to outer surface along the radial sections of the disc. Linear thermal loads were selected as to differ from each other. They were also adjusted from 90 to 130 °C. Thermal stresses were formed within the disc by the linear temperature loads due to its having different thermal expansion coefficients in radial and tangential directions. In line with the thermal analysis results, the magnitudes of the tangential stress components for both elastic and elastic–plastic solutions were above the radial stress components. In addition, the residual stress components were also calculated using both elastic and elastic–plastic solution results. The results obtained pointed out that the magnitudes and distributions of the thermal stresses and residual stresses were greatly influenced by the increase in linear temperature loads.     

User scheduling and power allocation for nonfull buffer traffic in NOMA downlink systems

Nonorthogonal multiple access (NOMA) is one of the key technologies for 5G, where the system capacity can be increased by allowing simultaneous transmission of multiple users at the same radio resource. The most of the proportional fairness (PF)–based resource allocation studies for NOMA systems assumes full buffer traffic model, while the traffic in real‐life scenarios is generally nonfull buffer. In this paper, we propose User Demand–Based Proportional Fairness (UDB‐PF) and Proportional User Satisfaction Fairness (PUSF) algorithms for user scheduling and power allocation in NOMA downlink systems when traffic demands of the users are limited and time‐varying. UDB‐PF extends the PF‐based scheduling by allocating optimum power levels towards satisfying the traffic demand constraints of user pair in each resource block. The objective of PUSF is to maximize the network‐wide user satisfaction by allocating sufficient frequency and power resources according to traffic demands of the users. In both cases, user groups are selected first to simultaneously transmit their signals at the same frequency resource, while the optimal transmission power level is assigned to each user to optimize the underlying objective function. In addition, the genetic algorithm (GA) approach is employed for user group selection to reduce the computational complexity. When the user traffic rate requirements change rapidly over time, UDB‐PF yields better sum rate (throughput) while PUSF provides better network‐wide user satisfaction results compared with the PF‐based user scheduling. We also observed that the GA‐based user group selection significantly reduced the computational load while achieving the comparable results of the exhaustive search.     

Investigation of the effect of rake angle and approaching angle on main cutting force and tool tip temperature

This paper deals with the comparison of measured and calculated results of cutting force components and temperature variation generated on the tool tip in turning for different cutting parameters and different tools having various tool geometries while machining AISI 1040 steel hardened at HRc 40. The geometric variables (approaching angle and rake angle) of the tool were changed using selected cutting parameters; thus, the cutting force components and temperature variations on tool face (in secondary shear zone) were determined. The selected cutting variables and the tools in different geometries were tested practically under workshop conditions. In this way, the essential information about the validity of selected values was obtained. During the tests, the depth of cut and cutting speed were kept constant and each test was conducted with a sharp uncoated tool insert. For making a comparison, the main cutting force/tangential force component for different cutting parameters and tool geometries were calculated by Kienzle approach and the temperature values were calculated based on orthogonal cutting mechanism. Finally, the effects of cutting parameters and tool geometry on cutting forces and tool tip temperature were analysed. The average deviation between measured and calculated force results were found as 0.37%. The cutting force signals and temperature values provided extensive data to analyse the orthogonal cutting process.     

A survey on packet size optimization for terrestrial,underwater, underground,and body area sensor networks

Packet size optimization is a critical issue in wireless sensor networks (WSNs) for improving many performance metrics (eg, network lifetime, delay, throughput, and reliability). In WSNs, longer packets may experience higher loss rates due to harsh channel conditions. On the other hand, shorter packets may suffer from greater overhead. Hence, the optimal packet size must be chosen to enhance various performance metrics of WSNs. To this end, many approaches have been proposed to determine the optimum packet size in WSNs. In the literature, packet size optimization studies focus on a specific application or deployment environment. However, there is no comprehensive and recent survey paper that categorizes these different approaches. To address this need, in this paper, recent studies and techniques on data packet size optimization for terrestrial WSNs, underwater WSNs, wireless underground sensor networks, and body area sensor networks are reviewed to motivate the research community to further investigate this promising research area. The main objective of this paper is to provide a better understanding of different packet size optimization approaches used in different types of sensor networks and applications as well as introduce open research issues and challenges in this area.     

Acidic leaching and precipitation of zinc and manganese from spent battery powders using various reductants

The main objective of this study was to investigate the effects of reductive acidic leaching and further precipitation on the recovery of manganese and zinc from spent alkaline and zinc–carbon battery powders. Ascorbic acid (AA), citric acid (CA) and oxalic acid (OA) were tested as the reductants. Sodium hydroxide and potassium hydroxide were used as precipitating agents. OA with H₂SO₄ or HCl was not effective on the leaching of zinc due to the formation of zinc oxalate precipitates. However, the other reducing agents (CA and AA) tested under various experimental conditions were effective in the acidic leaching of both zinc and manganese. Leaching yields of both manganese and zinc were higher at leach temperature of 90 °C than those at 30 °C. Leach solutions were purified by the selective precipitation of manganese and zinc using KOH or NaOH. Complete precipitation was obtained for Mn at pH 9–10 and for Zn at pH 7–8. The use of ascorbic acid or citric acid as reductants in acidic leaching appears to be effective in the simultaneous leaching and further recovery of zinc and manganese from spent alkaline and zinc–carbon battery powders.