THE PERFORMANCE OF LOW COST CUTTING TOOLS WHEN MACHINING HARDENED STEEL OF 60 HRC

Hard turning is a topic of great interest in today’s industrial production and scientific research. The hard turning technology has the potential for improving productivity against grinding in the manufacturing process. Today, tool manufacturers are constantly developing new combinations of coatings and substrates to precisely match different workpiece materials and operations. Nevertheless, the suitability of coated mixed ceramic (AI2O3 + TiCN) cutting tools when hard turning AISI D2 cold work tool steel (60 HRC) is yet to be investigated. An understanding of the tool life and wear mechanisms, surface integrity produced by coated mixed ceramic cutting tools will give an alternative to the manufacturing industries to exploit low costs cutting tools in hard turning of AISI D2 (60 HRC). The noticeable trend of the tool life was observed at test conditions where the cutting speed is at 100 m/min instead of 140 m/min or 200 m/min. The wear mechanism of coated mixed ceramic cutting tools with TiN is subjected to abrasion, adhesion, chipping and notching, especially when machining at high cutting speed of 200 m/min

DESIGN AND FABRICATION OF CRANIOPLASTY PROSTHESES: FIT EVALUATION BETWEEN PHANTOM-BASED HAPTIC ENVIRONMENT AND MATERIALISE 3-MATIC SOFTWARE

Two different design methods for customized cranioplasty prostheses are presented in this paper. The first approach is designing the digital model of the cranial implants in a haptic environment, utilizing a combination of a PHANToM haptic device and a freeform software called Claytools. The other method makes use of a software solution provided by Materialise Inc. known as 3-matic. Next, the skull models and the designed implants are fabricated via stereolitography (SLA). Finally, the implants’ fit over the skull models are evaluated to determine the most accurate method

Low-Prandtl-number B\'enard-Marangoni convection in a vertical magnetic field

The effect of a homogeneous magnetic field on surface-tension-driven B\'{e}nard convection is studied by means of direct numerical simulations. The flow is computed in a rectangular domain with periodic horizontal boundary conditions and the free-slip condition on the bottom wall using a pseudospectral Fourier-Chebyshev discretization. Deformations of the free surface are neglected. Two- and three-dimensional flows are computed for either vanishing or small Prandtl number, which are typical of liquid metals. The main focus of the paper is on a qualitative comparison of the flow states with the non-magnetic case, and on the effects associated with the possible near-cancellation of the nonlinear and pressure terms in the momentum equations for two-dimensional rolls. In the three-dimensional case, the transition from a stationary hexagonal pattern at the onset of convection to three-dimensional time-dependent convection is explored by a series of simulations at zero Prandtl number.Comment: 26 pages, 9 figure

6G wireless communications networks: a comprehensive survey

The commercial fifth-generation (5G) wireless communications networks have already been deployed with the aim of providing high data rates. However, the rapid growth in the number of smart devices and the emergence of the Internet of Everything (IoE) applications, which require an ultra-reliable and low-latency communication, will result in a substantial burden on the 5G wireless networks. As such, the data rate that could be supplied by 5G networks will unlikely sustain the enormous ongoing data traffic explosion. This has motivated research into continuing to advance the existing wireless networks toward the future generation of cellular systems, known as sixth generation (6G). Therefore, it is essential to provide a prospective vision of the 6G and the key enabling technologies for realizing future networks. To this end, this paper presents a comprehensive review/survey of the future evolution of 6G networks. Specifically, the objective of the paper is to provide a comprehensive review/survey about the key enabling technologies for 6G networks, which include a discussion about the main operation principles of each technology, envisioned potential applications, current state-of-the-art research, and the related technical challenges. Overall, this paper provides useful information for industries and academic researchers and discusses the potentials for opening up new research directions

EPIdemiology of Surgery-Associated Acute Kidney Injury (EPIS-AKI) : Study protocol for a multicentre, observational trial

More than 300 million surgical procedures are performed each year. Acute kidney injury (AKI) is a common complication after major surgery and is associated with adverse short-term and long-term outcomes. However, there is a large variation in the incidence of reported AKI rates. The establishment of an accurate epidemiology of surgery-associated AKI is important for healthcare policy, quality initiatives, clinical trials, as well as for improving guidelines. The objective of the Epidemiology of Surgery-associated Acute Kidney Injury (EPIS-AKI) trial is to prospectively evaluate the epidemiology of AKI after major surgery using the latest Kidney Disease: Improving Global Outcomes (KDIGO) consensus definition of AKI. EPIS-AKI is an international prospective, observational, multicentre cohort study including 10 000 patients undergoing major surgery who are subsequently admitted to the ICU or a similar high dependency unit. The primary endpoint is the incidence of AKI within 72 hours after surgery according to the KDIGO criteria. Secondary endpoints include use of renal replacement therapy (RRT), mortality during ICU and hospital stay, length of ICU and hospital stay and major adverse kidney events (combined endpoint consisting of persistent renal dysfunction, RRT and mortality) at day 90. Further, we will evaluate preoperative and intraoperative risk factors affecting the incidence of postoperative AKI. In an add-on analysis, we will assess urinary biomarkers for early detection of AKI. EPIS-AKI has been approved by the leading Ethics Committee of the Medical Council North Rhine-Westphalia, of the Westphalian Wilhelms-University Münster and the corresponding Ethics Committee at each participating site. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and used to design further AKI-related trials. Trial registration number NCT04165369

The effect of synthetic polyethylene fiber on the strain hardening behavior of engineered cementitious composite (ECC)

This research investigated the effects of polyethylene (PE) fibers on the toughness and compressive and flexural strengths of engineered cementitious composite (ECC) cubes and slabs. In particular, this study discussed the reinforcing index (R.I.) as the main parameter. Tests were conducted in direct tension to evaluate the strain-hardening behavior of ECC with different PE fiber contents. Flexural toughness was also assessed following the ASTM C1018 procedure and post-cracking strength technique (PCSm). Results showed that the compressive strength linearly decreased with the increase of the reinforcing index, which in turn decreased the first crack load and significantly increased the ultimate load and failure deflections, and the ultimate strength of slabs. The toughness indices 120 to I-100 significantly increased with the increase in reinforcing index and even exceeded the considered limitations. Based on the observed results, a new definition for the ECC PE was proposed as an extension to the definition given in ASTM C1018. All the residual strength factors increased when the reinforcing index increased, indicating a higher amount of the retained strength. Similarly, the retained strength had a higher amount when the PCS24 values increased with increase in the reinforcing indices. (C) 2015 Elsevier Ltd. All rights reserved

Qualitative analysis on the barriers of industrialised building system (IBS) uptake in Malaysian construction projects

Even though the construction industry is very competitive, it is currently very labor intensive. As such the Malaysian Government has been continuously encouraging the industry to use the Industrialised Building System (IBS), which is considered to be an important part of modern method construction approach. However, the system has so far failed to gather momentum especially among the private construction projects. Accordingly, many studies have been conducted for identifying the factors that contributed to this problem. However, the previous studies mostly focused on the qualitative data whereas the finding has limited discuss on ‘how’ and ‘why’ of the problem happened. Based on the findings from the industry workshop, this paper discusses the identified barriers with the aim of examining how far these barriers may well affect the process of IBS implementation in the Malaysian construction industry

CubeSat: LEO mission control unit potential communication concept for AMR system

The dramatic drop in equipment pricing, better services and efficiency of small satellite candidate is an interesting communication technology alternative for the deployment of Smart Grid (SG). The use of commercial-off-theshelf (COTS) components and the ongoing miniaturiza-tion of several technologies have already led to scattered instance of mission with promising scientific value. In this paper, the potential of Low Earth Orbit (LEO) Mission Control Unit (MCU) for small class satellite payloads is presented with the goal of providing utilities in-dustry to low cost and efficiency system towards enhancement of the services provided. Many commercial companies have emerged to cater this objective, however most of them provide an expensive LEO satellites solution. Therefore, this paper proposes a low cost and compact platform to substitute the conventional one. The proposed solution in this paper is targeting Automatic Meter Reading (AMR) system spe-cifically at rural area meter. In particular, this research is intended mainly for the researchers to start an exploration of new technology to be implemented in near future. Advanced development and assessment of CubeSats for SG will make it possible to be used as an alternative communication link

Effect of dietary purines on the pharmacokinetics of orally administered ribavirin

10.1177/0091270009335002Journal of Clinical Pharmacology496661-66