STUDY OF A CATEGORY ONE AIRPORT OPERATIONAL SAFETY AND SECURITY IN ABUJA, NIGERIA

This study assesses the operational safety and security of a category one airport in Nigeria, using the Nnamdi Azikiwe International Airport, Abuja (NAIA) as the case study airport. Data were sourced using structured questionnaire and oral interviews. A total of 180 questionnaires were administered and 165 questionnaires were retrieved, amounting to a 91.7% rate of response. The structured questionnaire used aimed at identifying various safety and security parameters in the study area. This study examined the trend of the effectiveness of safety and security variable in airport operations, safety and employee’s attitude towards safety risk management using the Multicriteria Decision Analysis model to achieve this objective. The results show the weighty level, satisfaction index and effective index of the safety and security parameters used in the analysis with their score and effective index graph. Recommendation on how to improve the airport safety operations were made following policy implication on how to improve the safety management system of the airport.

TE-Polarized SPPs in Nonlinear Multi-layer Graphene-Based Structures

In this article, an analytical model is proposed for the study of Transverse-electric (TE) surface plasmon polaritons (SPPs) in nonlinear multi-layer graphene-based waveguides. Each graphene sheet has been located between two different Kerr-type layers. As special cases of the general, proposed structure, two new nonlinear graphene-based waveguides are introduced and investigated in this paper. The obtained results show that the propagation properties of these exemplary structures are adjustable via chemical potential and nonlinear coefficients. A large value of the effective index, i.e. neff= 82 is obtained for the chemical potential of 0.15 eV and the nonlinear ratio of 0.8 for the second structure at the frequency of 61 THz. The presented study suggests a novel platform in graphene plasmonics, which can be used for the design of innovative THz devices.

Comparison of the ratio of placental territory discordance to birthweight discordance in placentas of monochorionic diamniotic twins

The ratio of placental territory discordance to birthweight discordance was calculated in monochorionic diamniotic twin placentas. We then determined whether the ratio: (1) correlated with the overall diameter of the placental superficial vascular anastomoses and (2) was different in normal monochorionic diamniotic twin (normal MCDA), twin-to-twin transfusion syndrome (TTTS), and selective intrauterine growth restriction (sIUGR) pregnancies. A prospective study of MCDA placentas was conducted from April 1, 2016, to April 1, 2019, including three groups, normal MCDA ( N = 49), TTTS ( N = 38), and sIUGR ( N = 52). Placentas were studied via dye injection. In the normal MCDA, sIUGR, and TTTS groups, the ratio positively correlated with the overall diameter of the placental superficial vascular anastomoses (Spearman’s = 0.295, 0.619, and 0.530; p = 0.040, <0.001, and 0.001, respectively) and gradually decreased from normal MCDA to sIUGR and to TTTS (2.88 (0.34, 64.25), 1.70 (0.27, 4.52), and 1.03 (0.12, 15.17); p < 0.001, p = 0.016/<0.001/0.005, respectively). The placental territory discordance to birthweight discordance ratio is an effective index reflecting the overall vascular anastomoses in MCDA placentas.

Theoretical Analysis of Terahertz Dielectric–Loaded Graphene Waveguide

The waveguiding of terahertz surface plasmons by a GaAs strip-loaded graphene waveguide is investigated based on the effective-index method and the finite element method. Modal properties of the effective mode index, modal loss, and cut-off characteristics of higher order modes are investigated. By modulating the Fermi level, the modal properties of the fundamental mode could be adjusted. The accuracy of the effective-index method is verified by a comparison between the analytical results and numerical simulations. Besides the modal properties, the crosstalk between the adjacent waveguides, which determines the device integration density, is studied. The findings show that the effective-index method is highly valid for analyzing dielectric-loaded graphene plasmon waveguides in the terahertz region and may have potential applications in subwavelength tunable integrated photonic devices.

Effects of Acupuncture and Moxibustion on Breast Cancer-Related Lymphedema: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective: The aim of this systematic review and meta-analysis of randomized controlled trials (RCTs) was to evaluate the effects of acupuncture and moxibustion (AM) in women with breast cancer-related lymphedema (BCRL). Methods: We retrieved RCTs published before January 24, 2021, from the MEDLINE, EMBASE, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), Chongqing VIP (VIP), and Wanfang databases. RCTs that compared acupuncture and/or moxibustion intervention with other treatments were included. A random effects or fixed effects model was used based on the heterogeneity findings. Study quality was evaluated using the Cochrane risk of bias tool. Results: We included 14 RCTs in the analyses, of which 4 RCTs adopted acupuncture, 4 RCTs used moxibustion, and the rest used both. AM significantly reduced arm circumference at the elbow crease compared to routine care (Mean deviation (MD) = −7.26, 95% confidence interval (CI) = −8.30 to −6.21, P < .00001). There was a significant difference between AM and diosmin tablets in the effective index for upper limb lymphedema (MD = 24.68, 95% CI = 24.82-30.53, P < .00001), the range of motion of the shoulder during protraction (MD = 6.77, 95% CI = 2.81-10.73, P = .0008), and adduction (MD = 4.17, 95% CI = 1.02-7.32, P = .01). There was a significant difference between moxibustion and pneumatic circulation (MD = −0.51, 95% CI = −0.85 to −0.17, P = .003) in the visual analog score (VAS) for swelling. Finally, compared to the blank control, acupuncture reduced the VAS for pain (MD = −1.33, 95% CI = −1.52 to −1.15, P < .00001; heterogeneity ( I2) = 0%, P = .57). Conclusion: Our results suggest that AM is effective in the treatment of BCRL. AM may reduce arm circumference at the elbow crease (compared to routine care), increase effective index for upper limb lymphedema (compared to oral diosmin tablets), improve the range of motion of the shoulder during protraction and adduction (compared to oral diosmin tablets), and decrease the VAS for both swelling (compared to pneumatic circulation) and pain (compared to blank control).

Analysis of rotor asymmetry fault in three-phase line start permanent magnet synchronous motor

This article proposed a detection scheme for three-phase Line start permanent magnet synchronous motor (LSPMSM) under different levels of static eccentricity fault. Finite element method is used to simulate the healthy and faulty LSPMSM with different percentages of static eccentricity. An accurate laboratory test experiment is performed to evaluate the proposed index. Effects of loading condition on LSPMSM are also investigated. The fault related signatures in the stator current are identified and an effective index for LSPMSM is proposed. The simulation and experimental results indicate that the low frequency components are an effective index for detection of the static eccentricity in LSPMSM.