Development of laser direct writing for fabrication of micro/nano-scale magnetic structures

Traditional lithographic techniques used to fabricate a magnetic structure are often complex, time consuming, dependent on other techniques and expensive. Laser direct writing (LDW) can potentially overcome many of these drawbacks and may be a cheaper, faster and easier route to fabricating technique micro-/nano-magnetic structures. The main aim of this project is to fabricate magnetic structures through LDW. Two types of LDW were used to fabricate magnetic structures: subtractive LDW (LDW-) and laser-induced forward transfer (LIFT). LIFT was used to transfer permalloy (Ni81Fe19) using three laser systems. Numerous parameters were varied, including thin film thickness, scanning speed, pulse energy, distance between donor/acceptor and acceptor material. These attempts did not succeed in transferring the magnetic materials as a uniform shape. The differences of heat conductivity between the permalloy and acceptor substrate (glass and silicon), shock wave effects and the landing speed of material on the acceptor are the most possible reasons that the uniform structures and the magnetic properties were lost. LDW- was used to successfully pattern 90nm thick Permalloy into 1-D and 2-D microstructures. Magnetic wires with a range of widths, arrays of squares, rectangles with a range of aspect ratios and rhombic elements were patterned. These structures were fabricated using an 800-picosecond pulse laser and a 0.75 NA lens to give a 1.85µm diameter spot. Scan speeds were controlled to give 30% overlap between successive laser pulses and reduce the extent of width modulation in the final structures compared with lower levels of pulse overlap. Continuous magnetic wires that adjoined the rest of the film were fabricated with widths from 150 nm - 6.7µm and showed coercivity reducing across this range from 47 Oe to 10 Oe. Squares, rectangles and diamonds These elements demonstrated shape-sensitive magnetic behaviour with increasing the shape aspect ratio. Wires of different width were also fabricated by LDW- and their anisotropic magnetoresistance (AMR) determined to show a simple width-dependent magnetic field response, making them interesting as magnetic field sensors. This approach is extremely rapid and does not requires masks or chemical processing as part of the patterning procedure. The time required to patterned 1-D area of 4 x 0.18 mm was 85 s and the average fabrication time per element of 2-D structures was 4.7x10 4 s. The microstructures may be of use for AMR sensors or for biological applications, such as cell trapping

Cancer risk (ELCR) and annual gonadotropin equivalent dose (AGED) in macaroni

Natural radioactivity has attracted a lot of attention in the world due to its crucial role in human safety. macaroni (Macaroni) is a dry, hollow pastry, made from cereals such as wheat, rice and barley. Macaroni is one of the basic and important for human beings, as well as its proven usefulness to the general health of human beings. Therefore, the measurement of natural radioactivity is a critical because of its direct impact on human safety. In this research, quantification has been made of natural radionuclide concentrations using NaI(Tl) gamma-ray spectrometry. The analyses of samples reveal the mean activity concentrations of 226Ra, 232Th, 40K%  are found to 4.5E-01±0.071, 4.46±0.163 and 2.14±0.021, respectively. RLI,AUI,IC and Iα  were also calculated  the values ​​were less than one also  estimated annual gonadal equivalent dose (AGED) resulting with an average 302.98±07.59 mSv.y-1 where was higher than globally limits. Consumption of macaroni for adult was found (0.035±0.0015) mSv.y-1 which less than global studies , while the average value of cancer risk (  1.21E-04±0.000005*10-3 mSv.y-1 Below the international permissible limits. The study can be considered as a basis for future studies on this basic substance in food.                                                                                                         &nbsp

SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

Background: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods: The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18-49, 50-69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results: NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion: As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population