Correction to: Towards achieving nanofinish on silicon (Si) wafer by μ-wire electro-discharge machining

[No abstract available]This work was supported by the Fundamental Research Grant (FRGS/1/2014/TK01/UIAM/02/2) sponsored by the Ministry of Higher Education Malaysia. Authors also acknowledge the research support provided by the International Islamic University Malaysia

Breast cancer management pathways during the COVID-19 pandemic: outcomes from the UK ‘Alert Level 4’ phase of the B-MaP-C study

Abstract: Background: The B-MaP-C study aimed to determine alterations to breast cancer (BC) management during the peak transmission period of the UK COVID-19 pandemic and the potential impact of these treatment decisions. Methods: This was a national cohort study of patients with early BC undergoing multidisciplinary team (MDT)-guided treatment recommendations during the pandemic, designated ‘standard’ or ‘COVID-altered’, in the preoperative, operative and post-operative setting. Findings: Of 3776 patients (from 64 UK units) in the study, 2246 (59%) had ‘COVID-altered’ management. ‘Bridging’ endocrine therapy was used (n = 951) where theatre capacity was reduced. There was increasing access to COVID-19 low-risk theatres during the study period (59%). In line with national guidance, immediate breast reconstruction was avoided (n = 299). Where adjuvant chemotherapy was omitted (n = 81), the median benefit was only 3% (IQR 2–9%) using ‘NHS Predict’. There was the rapid adoption of new evidence-based hypofractionated radiotherapy (n = 781, from 46 units). Only 14 patients (1%) tested positive for SARS-CoV-2 during their treatment journey. Conclusions: The majority of ‘COVID-altered’ management decisions were largely in line with pre-COVID evidence-based guidelines, implying that breast cancer survival outcomes are unlikely to be negatively impacted by the pandemic. However, in this study, the potential impact of delays to BC presentation or diagnosis remains unknown

Energy efficient dual axis solar tracking system using IOT

With the increasing demand for energy, traditional sources are becoming scarce and the need to transition to non-traditional sources of energy is urgent. Solar energy is an inexhaustible form of energy that can be easily tapped from different parts of the world and converted to electrical energy by using devices such as solar panels. However, the output power of these photovoltaic (PV) panels is not constant as the sun moves from east to west and its angle of incidence varies with the season and time of the day. To maximize energy output from the solar panel, a dual-axis solar tracker (DAST) is necessary to rotate the panel about its horizontal and vertical axes. This system will ensure efficient tracking of the sun and optimal energy output from the solar panel. The proposed system will respond within the 0.2 s to store the data in database. The whole 24 h data of solar panel is utilized in the preferred system to analyse the data to validate the robustness of the system. The proposed system uses a microcontroller to adjust the position of the solar panel based on the movement of the sun, while the performance of the tracker is monitored through the use of Internet of Things (IoT) connected via Wi-Fi

Role of Pulse Pressure and Geometry of Primary Entry Tear in Acute Type B Dissection Propagation

The hemodynamic and geometric factors leading to propagation of acute Type B dissections are poorly understood. The objective is to elucidate whether geometric and hemodynamic parameters increase the predilection for aortic dissection propagation. A pulse duplicator set-up was used on porcine aorta with a single entry tear. Mean pressures of 100 and 180 mmHg were used, with pulse pressures ranging from 40 to 200 mmHg. The propagation for varying geometric conditions (%circumference of the entry tear: 15–65%, axial length: 0.5–3.2 cm) were tested for two flap thicknesses (1/3rd and 2/3rd of the thickness of vessel wall, respectively). To assess the effect of pulse and mean pressure on flap dynamics, the %true lumen (TL) cross-sectional area of the entry tear were compared. The % circumference for propagation of thin flap (47 ± 1%) was not significantly different (p = 0.14) from thick flap (44 ± 2%). On the contrary, the axial length of propagation for thin flap (2.57 ± 0.15 cm) was significantly different (p < 0.05) from the thick flap (1.56 ± 0.10 cm). TL compression was observed during systolic phase. For a fixed geometry of entry tear (%circumference = 39 ± 2%; axial length = 1.43 ± 0.13 cm), mean pressure did not have significant (p = 0.84) effect on flap movement. Increase in pulse pressure resulted in a significant change (p = 0.02) in %TL area (52 ± 4%). The energy acting on the false lumen immediately before propagation was calculated as 75 ± 9 J/m(2) and was fairly uniform across different specimens. Pulse pressure had a significant effect on the flap movement in contrast to mean pressure. Hence, mitigation of pulse pressure and restriction of flap movement may be beneficial in patients with type B acute dissections

An experimental investigation on the effect of nanopowder for micro-wire electro discharge machining of gold coated silicon

Micro Wire Electro Discharge Machining (μ-WEDM) is a type of electro-discharge machining (EDM) process where the wire is used instead of a rigid tool. It is a reliable and precise machining process, which is commonly used to produce various complex structural shapes for a wide range of industrial applications. However, to machine a semiconductor material of high resistivity like silicon (Si) requires more advanced processing to produce larger electrical sparks during the μ-WEDM operation. Current (μ-WEDM) technology is not enough to realize a stable machining environment for Si. In this research, a new type of μ-WEDM process for Si machining was investigated. At first, Si was temporarily coated with gold and then nanopowder mixed dielectric medium was used for the WEDMing process. The main purpose of this work is to investigate the effects of different nanopowder concentrations on two important response factors such as material removal rate (MRR) and spark gap (SG). In this regard, the μ-WEDMing of gold coated silicon was carried out in pure dielectric EDM oil and also in three different concentrations (0.1g/L,1g/L,2g/L) of nanopowder mixed dielectric oil to conduct an initial study with the aim to achieve better machining accuracy and stability. Based on the experimental investigations, the MRR were found to be increased on average minimum ∼ 1% to maximum ∼ 33% respectively for different carbon concentrations, as compared to machining in the pure dielectric medium. The spark gap was also observed to be increased by a significant margin on average of ∼ 2% to up to ∼ 159% than without using any nanopowder concentration, correspondingly

Design and fabrication of compact fluorescent lamp igniter using TRIAC-assisted high-voltage DC source

A potential approach for designing and fabricating igniter for compact fluorescent lamp is introduced using high-voltage DC (HVDC) source which is controlled by gate pulse obtained from TRIAC-based firing circuit. The Cockroft-Walton voltage multiplier circuit is used to design HVDC (2 kV) sourc e where i ni ti al ly opti ma l rati ng of c apac it anc e f or each stage was considered based on experimental analysis. This design was further simulated by Multisim 11 and characterised experimentally. The response obtained by this method reveals that the HVDC source is able to ignite the fluorescence lamp potentially than the conventional available ignition processes. The major advantages of using HVDC are lower power to ignite fluore sc enc e l amp, longer li fe and cost ef fe ct ive