Analysis on tool life and surface characteristic in milling Stavax Supreme material

Stavax Supreme material is classified as difficult-to-machine material. The difficulty does not preclude the use of this material, especially in the mold industry. In this experiment, high speed end milling of Stavax Supreme (52 HRC) was investigated using five different types of tool. Performance of the cutting tools was compared with respect to tool life and surface roughness of the workpiece. Machining process was conducted in two parameters where each parameter used different rotation spindle speed and feed rate but same chip per tooth removal rate. The best cutting performance was obtained with TiN and TiCN. TiAlN tool also proved to be suitable for high speed end milling of Stavax Supreme but for finishing process only because fast tool wear in high spindle speed. The Xceed coated tool is more suitable for roughing process only in high spindle speed

SERVICEABILITY BEHAVIOR OF NORMAL AND HIGH-STRENGTH REINFORCED CONCRETE T-BEAMS

Serviceability behavior of Normal Strength Concrete (NSC) and High Strength Concrete (HSC) T-beams was experimentally evaluated. The crack pattern was observed, the effect of flange dimensions (breadth and thickness) on the crack pattern and load-deflection response was evaluated experimentally for 10 beams comprising the two studied groups, NSC and HSC T-beams. The short-term deflections were measured experimentally and predicted empirically under mid-span concentrated loading. It was found that increasing the flange width and thickness resulted in higher loads and lower deflections under service loads to a different extent. Prior to failure, the increment in the maximum loads was up to 22% while the deflection reduced by 31% for NSC and 23% for HSC beams. The available equations for determining the effective moment of inertia (Ie) were reviewed and used in predicting the Ie of the cracked beam. The results were compared with the experimental values (Iexp). The Ie showed a noticeable difference, especially for the HSC T-beams. New equations were proposed in which the tensile reinforcement ratio was considered. Compared with the other available equations, the proposed equations demonstrated a better agreement and repeatability of predicting experimental results studied herein. In addition, the proposed equations were used to predict the Ie for experimentally tested T-beams available in the literature. The proposed models showed a high degree of accuracy

Impact of ablation time on Cu oxide nanoparticle green synthesis via pulsed laser ablation in liquid media

Large-scale commercial production of nanoparticles via efficient, economical, and environmentally friendly methods is a challenging endeavour. The laser ablation method being a green and potential route of nanoparticles synthesis can be exploited to achieve this end. In this work, we report the ablation of a copper target submerged in distilled water by pulsed Nd:YAG laser. The influence of ablation time on the structure and optical properties of grown copper oxide nanoparticles are studied. Such nanoparticle composition and structure is determined by X-ray diffraction (XRD), Fourier transform infrared, and Raman analyses. Results from transmission electron microscopy images established that synthesised nanoparticles are a spherical shape with average sizes of 24–37 nm. Fluorescence spectra revealed the enhancement of nanoparticle concentration and reduction in the sizes with increasing ablation time, where the optimum ablation time is demonstrated to be 60 min. Photoluminescence spectra exhibited a prominent visible peak (green), which blueshifted from 542 to 537 nm, confirming the shrinkage of copper oxide particle size at higher ablation time. The XRD pattern showed that the prepared nanoparticles possess a single phase of monocline cupric oxide nanostructure

The prevalence of obesity and the knowledge, attitude and practice of healthy lifestyle among the adult population in Kampung Banyuk, Kampung Kerto and Kampung Langup

Background Obesity has become a great public health concern and prevent!ive measures need to be done. Objective The objective of this research is to determine the prevalence ofobesity and their knowledge, attitude and practices (KAP) towards a healthy lifestyle among the residents in Kampung Banyok, Kampung Kerto and Kampung Langup. Methods A cross-sectional study was done among 126 randomly selected villagers aged 18 years and above from the three selected villages. They were interviewed based on a questionnaire and their body mass index (BMI) was calculated. Results It was found that more than half of the respondents are obese. Among the respondents, for the healthy lifestyle component, the level of good KAP is 69.2%, 46.8% and 60.3% respectively. As for obesity component, the level of good KAP is 60.3%, 54% and 54.8% respectively. Among the obese respondents, the level of knowledge and attitude on healthy lifestyle and obesity is better. Obese respondents have better obesity preventive practice while the non-obese respondents have better practice on healthy lifestyle. The only significant correlation noted was between knowledge and practice on obesity albeit a negative one. Conclusion The level of knowledge and attitude and practice on healthy lifestyle among the obese respondents are encouraged but more effort in the preventive practice ofobesity shou1d be done to reduce the prevalence.

Machining of injection mould materials for different cutting flute in low-speed end milling

The complexity of mould shapes and the hardness of the mould material contribute to difficulties in machining. Examination of the capability of atypeof cutting tool (Tungsten Carbide Ball Nose) towards machining mould material that is usually used in Injection Moulding Industries. Following this, an experimental work was detailed relating to the use of ball nose end mill to machine hardened injection mould materials (up to 62 HRC).Surface roughness, surface topography and tool wear data were presented. The relationships of all these three properties respect to each other were also investigated. By machining these materials (Stavax, Stainless Steel, DF3 and XW5), a major wear occur on cutting tool which is called flank wear. Theflank wear is increased by increasing the hardness of the material used. This fact was supported by the result obtained, in which the surface roughness increases when the material hardness increased. Surface topography isdescribed through wavy marks and surface tearing. For 2 and 4-flute cutting tools, the waviness phenomenal ondecreases when material hardness was increased. Meanwhile, for surface tearing, the rate of occurrence is proportional to the increment of the material hardness

Responsivity Dependent Anodization Current Density of Nanoporous Silicon Based MSM Photodetector

Achieving a cheap and ultrafast metal-semiconductor-metal (MSM) photodetector (PD) for very high-speed communications is ever-demanding. We report the influence of anodization current density variation on the response of nanoporous silicon (NPSi) based MSM PD with platinum (Pt) contact electrodes. Such NPSi samples are grown from n-type Si (100) wafer using photoelectrochemical etching with three different anodization current densities. FESEM images of as-prepared samples revealed the existence of discrete pores with spherical and square-like shapes. XRD pattern displayed the growth of nanocrystals with (311) lattice orientation. The nanocrystallite sizes obtained using Scherrer formula are found to be between 20.8 nm and 28.6 nm. The observed rectifying behavior in the I-V characteristics is ascribed to the Pt/PSi/n-Si Schottky barrier formation, where the barrier height at the Pt/PSi interface is estimated to be 0.69 eV. Furthermore, this Pt/PSi/Pt MSM PD achieved maximum responsivity of 0.17 A/W and quantum efficiency as much as 39.3%. The photoresponse of this NPSi based MSM PD demonstrated excellent repeatability, fast response, and enhanced saturation current with increasing anodization current density

Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

© 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 licenseBackground: 80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality. Methods: This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494. Findings: Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70–8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39–8·80) and upper-middle-income countries (2·06, 1·11–3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26–11·59) and upper-middle-income countries (3·89, 2·08–7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications. Interpretation: Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications. Funding: National Institute for Health Research Global Health Research Unit