Elliptical ultra-wideband antenna sensor with modified time reversal algorithm for breast tumour localization

Breast cancer is a serious health problem and the second leading cause of death around the globe. The skin around fatty tissues like the breast are the most common and fastest growing of all cancer types. Thus, ultra-wideband (UWB) antenna sensors are considered a promising instrument in microwave imaging tomography with the least destruction in the body’s tissue. Several studies have recommended UWB antennas to acquire the target’s characteristics and localize them. However, they showed some limitations in terms of bandwidth and resolution to even spending larger printing areas despite showing acceptable outcomes. In addition, the imaging algorithms are usually utilized to combine and sum all the received signals, create an image of the dielectric scatter (tumour) within the human organ, and remove the clutters and artifacts. However, the problem is how to apply and utilize an algorithm for microwave imaging to reconstruct the image of the target in a cluttered environment (like skin and breast) with the most possible artifact and clutter removal (not to mask the tumour response). Therefore, this thesis proposes a UWB antenna sensor with good directional beamwidth, high fidelity, high efficiency, and low group delay at the frequency range of 0-30 GHz. A novel weighted Time Reversal algorithm is introduced to improve the image quality along with removing the clutter in the imaging environment. The proposed elliptical patch antenna sensors loaded by stubs, slots, and truncated ground show complementary results for the imaging of breast skin as they achieve broad BW (>18 GHz), simple elliptical shape of the patch, miniaturized dimensions (15 × 15 mm2), and high fidelity (> 90 % hence low distortion). Notably, there is a good agreement shown between the simulation and measurement results of the proposed antenna. The imaging results show that the proposed algorithm obtained better results in terms of accurate localization, and better removal of image artifacts and clutter. It has shown the accuracy with more than 95 % detection of tumours in breast skin and can perform a hollow with a diameter of 3 mm in any location within the trunk. Besides, no significant discrepancy exists between the images using simulated and measured scattering indicates the system’s ability to the detection of tumours in the breast skin

New CPW-Fed Broadband Circularly Polarized Planar Monopole Antenna Based On A Couple Of Linked Symmetric Square Patches

A new broadband circularly polarized planar monopole antenna with coplanar waveguide feeding (CPW-fed) is proposed. This antenna consists of a couple of linked symmetric square patches (CLSSP), an asymmetric ground plane and two strips connected to the left ground plane by the CLSSP radiator and a straight strip. A broad impedance bandwidth (IBW) is achieved. Moreover, a broad axial ratio bandwidth (ARBW) is obtained by using an asymmetric ground plane and an inverted L-shaped strip. Simulation results demonstrate that IBW reaches 119% (1.56-6.18 GHz) and ARBW is 88.9% (2-5.2 GHz). The latter is completely overlapped by the simulated IBW. In addition, antenna performance is investigated by studying different parameters

Design Of Helical Antenna For Next Generation Wireless Communication

This study proposes a novel helical antenna design for next generation applications. The strip helical antenna is prescribed for next generation wireless communication and wideband applications that offer circular polarization and a wide bandwidth. In fact, the proposed helical antenna suits 5.8 GHz frequency by using Teflon material. The newly-designed strip was printed on a substrate and rolled into a helix shape to achieve circular polarization without impedance matching. This antenna is meant for wideband wireless communication applications. A wide bandwidth of 2.7 GHz with 5.8 GHz resonant frequency was attained through the use of helical antenna on Teflon substrate. The proposed antenna on Teflon substrate recorded a gain of 8.97 dB and 92% efficiency. The antenna design parameters and the simulated results were retrieved using Computer Simulation Technology software (CST). The measurement result of return loss displayed mismatch at 5.22 GHz due to manual fabrication. This developed antenna may be applied for a number of wireless applications, including Wideband, Ultra-wideband, and 5G

Gender Differences and Foreign Language Reading Anxiety of High School Learners in an Iraqi EFL Context

Over the past two decades Investigation of foreign language anxiety generally has progressively caught the attention of numerous investigators in the area of foreign language. Yet, anxiety variable that affects the students’ acquisition of particular language skills for instance, reading specifically have actually seldom been investigated in the context of EFL Arab learners in particular with Iraqi students. So, the study aimed to investigate the influence of anxiety variable towards reading comprehension of Iraqi high school learners. This study also sought to examine the gender differences towards reading language anxiety. Quantitative approach was applied in this research, which involved 20 Iraqi students of a high school in Kuala Lumpur, Malaysia. The respondents comprised 10 males and 10 females with ages between 16 years and 18 years. This study made use of Foreign Language Reading Anxiety Scale (FLRAS). The results of the study showed that both male and female participants had a high level of anxiety towards the reading comprehension. Furthermore, the analysis revealed that gender played a slight role in the results of the study. Female students showed a slightly higher level of anxiety towards the reading comprehension than their male counterparts. Iraqi learners need to be exposed to the four skills of English language generally and the reading skill in particular. This exposure makes the learners aware of the four skills (Listening, Reading, Writing and Speaking) that need to be acquired and also to decrease the rate of anxiety variable in addition to its influence on their performance

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