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Graphene oxide coated side polished surface plasmon resonance optical fibre sensor with varying polishing losses
No full textFour batches of side-polished SMF optical fibres with different polishing losses, − 0.5 dBm, − 5 dBm, − 10 dBm and − 15 dBm were coated with a graphene oxide layer of ~ 0.5 μm via drop casting. TE polarized light was propagated through the light during experiments and four different transformer oils with different water contents were dropped onto the sensor. The drop in the power of transmitted light was recorded. The responses of the sensors showed good linearity for all, but the least polished fibre showed the weakest response in terms of power drop towards change in concentration. The − 5 dBm fibre showed the best response per unit concentration change. Additional tests showed the increased response for a GO coated side polished sensor compared to an uncoated side polished sensor. Simulation using COMSOL was performed to show the effects on the electric field of a sensor with and without GO coating. Another set of simulations were performed to show the effects of reducing cladding thickness on the coupling of the electric field. Simulations show that the optimal cladding thickness is not the most polished fibre, coinciding with our results that − 15 dBm loss fibre did not show the most response per unit change in the analyte. © 2019, Springer Science+Business Media, LLC, part of Springer Nature
Holmium oxide thin film as a saturable absorber for generating Q-switched and mode-locked erbium-doped fiber lasers
No full textWe demonstrated a new type of transition metal oxide (TMO) material, Holmium oxide (Ho2O3) polymer film SA for compact passively Q-switched and mode-locked erbium-doped fiber laser (EDFL) generations. The film SA has a thickness of ~40 µm and modulation depth of ~45%. It was fabricated by embedding Ho2O3 nanoparticles into PVA polymer solution. The Q-switched laser operated stably at a center wavelength of 1563 nm within a pump power range of 45–97 mW. The maximum Q-switching pulse repetition rate and the narrowest attainable pulse width were 115.8 kHz and 0.64 µs, respectively; while, the maximum pulse energy was obtained as 129.36 nJ. On the other hand, the mode-locked EDFL emerged stably within a pump power range of 62–180 mW at a center wavelength of 1565.4 nm. The repetition rate was 17.1 MHz, while the pulse width was 650 fs. Additionally, the maximum output power was measured as 9.01 mW; while, the corresponding maximum pulse energy was obtained as 0.524 nJ. This Ho2O3 film SA offers simplicity and reliability in the design of compact and portable fiber pulsed laser generators particularly in the 1.55-µm regime. © 201
Daily exposure to toxic metals through urban road dust from industrial, commercial, heavy traffic, and residential areas in Petaling Jaya, Malaysia: a health risk assessment
No full textHuman health is threatened by significant emissions of heavy metals into the urban environment due to various activities. Various studies describing health risk analyses on soil and dust have been conducted previously. However, there are limited studies that have been carried out regarding the potential health risk assessment of heavy metals in urban road dust of < 63-μm diameter, via incidental ingestion, dermal contact, and inhalation exposure routes by children and adults in developing countries. Therefore, this study evaluated the health risks of heavy metal exposure via ingestion, dermal contact, and inhalation of urban dust particles in Petaling Jaya, Malaysia. Heavy metals such as lead (Pb), chromium (Cr), zinc (Zn), copper (Cu), and manganese (Mn) were measured using dust samples obtained from industrial, high-traffic, commercial, and residential areas by using inductively coupled plasma mass spectrometry (ICP-MS). The principal component and hierarchical cluster analysis showed the dominance of these metal concentrations at sites associated with anthropogenic activities. This was suggestive of industrial, traffic emissions, atmospheric depositions, and wind as the significant contributors towards urban dust contamination in the study sites. Further exploratory analysis underlined Cr, Pb, Cu, and Zn as the most representative metals in the dust samples. In accommodating the uncertainties associated with health risk calculations and simulating the reasonable maximum exposure of these metals, the related health risks were estimated at the 75th and 95th percentiles. Furthermore, assessing the exposure to carcinogenic and non-carcinogenic metals in the dust revealed that ingestion was the primary route of consumption. Children who ingested dust particles in Petaling Jaya could be more vulnerable to carcinogenic and non-carcinogenic risks, but the exposure for both children and adults showed no potential health effects. Therefore, this study serves as an important premise for a review and reformation of the existing environmental quality standards for human health safety. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature
Clinical Evaluation of a Portable System for Capturing Nystagmus (PSCN) as an Alternative to Videonystagmography
No full textObjective: To develop a portable and affordable system for diagnosing pathological horizontal nystagmus (oscillatory rapid eye movement) in remote clinics. It is aimed to be a temporary alternative to the golden standard tool which is the Video Nystagmography which is expensive and office-based equipment. Method: The team created a system composed of a hardware gadget and software application. The modified goggle with a built-in camera and microcontroller is used to record and analyze the induced nystagmus. The analyzed data is then transmitted via Bluetooth to the user portable device which displays the results. Programming PSCN, it was tested in the outpatient clinic. During the clinical evaluation of the gadget, the nystagmus was induced and recorded by the Video Nystagmography. Immediately, we repeated the experiment using the created system. Eventually, the two results were compared to set up the thresholds in the new system. After calibration, the amended algorithm of PSCN tested another ten recorded nystagmus videos to evaluate its accuracy. Results: The portable system showed high clinical reliability during the testing in comparison to golden standard Videonystagmography. In the second stage, it showed an accuracy ratio up to 80 % during testing the ten recorded videos. It also managed to differntiate the real nystagmus from the artifacts. Conclusion: This trial proofed the concept of portable system as an assistive diagnostic tool for pathological nystagmus. However, a more clinical trial is required to establish it as a portable alternative for the golden standard. © Copyright 2019 by Gazi University Medical Faculty
Comparative numerical study of the dynamics, ion beam and flow energetics of fast and slow focus modes in a 2 kJ plasma focus operated in various gases
No full textComparative study of fast focus mode (FFM)and slow focus mode (SFM)of INTI Plasma Focus device at 12 kV, based on Lee Model, are presented in this paper. Results of numerical experiments for D, Ne, and Ar gases at different pressure ranges show that as a rule-of-thumb, diameter-optimized SFM is considered to occur when fast plasma stream speed generated by pinch column is equal to the peak axial phase speed. SFM occurs at the high-pressure range of operation when beam ion energy is typically less than a few keV. Results of speed factor, fast ion beam energy, FPS energy, FIB damage factor, plasma footprint radius for FFM and SFM at different pressures of D, Ne, and Ar are presented. These results may be used to predict different applications of both modes: for example, the intense beam and flow energetics in FFM may be of interest in irradiation of surfaces for damage studies; whilst in SFM, the larger area of reduced intensity of plasma flow and very low energy per beam ion result in more uniform irradiation over a larger area of target. This larger more uniform area of irradiation has distinct advantages in nanophase material synthesis by diameter-optimized SFM. © 2019 Elsevier Lt
Shoreface facies model of Cretaceous Jessu Formation, Yola Sub-basin, Northern Benue Trough, northeast Nigeria: New insights from facies analysis and molecular geochemistry
No full textThe Yola Sub-basin in the Northern Benue Trough is a frontier exploration basin in northeastern Nigeria and to date, there is no subsurface data available. The oldest sedimentary unit in the Yola Sub-basin is the Bima Formation, followed by Yolde, Dukul, Jessu, Sekuliye, Numanha and Lamja Formations, ranging in age from Berremian-Aptian-Albian to Santonian. The sediments of Jessu Formation were studied based on facies analysis (lithofacies and palynofacies) and geochemistry (biomarker distribution) with an objective of analysing and interpreting the source input/origin, paleodepositional conditions, paleodepositional environment and to reconstruct depositional and facis model for the studied successions. The study revealed that the sediments were deposited in a distal oxic-suboxic to relatively anoxic shelf (shallow marine) environment with both aquatic,-marine and terrestrially derived source inputs. Depositional framework indicate a progradational wave and storm-dominated shoreface-offshore facies succession, displaying a coarsening upward trend. This represent a regressive shoreface-offshore depositional system, consistent with earlier interpretations that the Cretaceous sediments of Jessu Formation were deposited during a brief regressive phase in the Northern Benue Trough. © 2019 Elsevier Lt
Effectiveness of Nature-Inspired Algorithms using ANFIS for Blade Design Optimization and Wind Turbine Efficiency
No full textBlade design of the horizontal axis wind turbine (HAWT) is an important parameter that determines the reliability and efficiency of a wind turbine. It is important to optimize the capture of the energy in the wind that can be correlated to the power coefficient (Cp) of HAWT system. In this paper, nature-inspired algorithms, e.g., ant colony optimization (ACO), artificial bee colony (ABC), and particle swarm optimization (PSO) are used to search for the blade parameters that can give the maximum value of Cp for HAWT. The parameters are tip speed ratio, blade radius, lift to drag ratio, solidity ratio, and chord length. The performance of these three algorithms in obtaining the optimal blade design based on the Cp are investigated and compared. In addition, an adaptive neuro-fuzzy interface (ANFIS) approach is implemented to predict the Cp of wind turbine blades for investigation of algorithm performance based on the coefficient determination (R 2 ) and root mean square error (RMSE). The optimized blade design parameters are validated with experimental results from the National Renewable Energy Laboratory (NREL). It was found that the optimized blade design parameters were obtained using an ABC algorithm with the maximum value power coefficient higher than ACO and PSO. The predicted Cp using ANFIS-ABC also outperformed the ANFIS-ACO and ANFIS-PSO. The difference between optimized and predicted is very small which implies the effectiveness of nature-inspired algorithms in this application. In addition, the value of RMSE and R 2 of the ABC-ANFIS algorithm were lower (indicating that the result obtained is more accurate) than the ACO and PSO algorithms. © 2019 by the authors
An intelligent based-model role to simulate the factor of safe slope by support vector regression
No full textAn infrastructure development in landscape and clearing of more vegetated areas have provided huge changes in Malaysia gradually leading to slope instabilities accompanied by enormous environmental effects such as properties and destructions. Thus, prudent practices through vegetation incorporating to use slope stability is an option to the general stabilized technique. Few researches have investigated the effectiveness of vegetative coverings related to slope and soil parameters. The main goal of this study is to provide an intelligent soft computing model to predict the safety factor (FOS) of a slope using support vector regression (SVR). In the other words, SVR has investigated the surface eco-protection techniques for cohesive soil slopes in Guthrie Corridor Expressway stretch through the probabilistic models analysis to highlight the main parameters. The aforementioned analysis has been performed to predict the FOS of a slope, also the estimator’s function has been confirmed by the simulative outcome compared to artificial neural network and genetic programing resulting in a drastic accurate estimation by SVR. Using new analyzing methods like SVR are more purposeful than achieving a starting point by trial and error embedding multiple factors into one in ordinary low-technique software. © 2018, Springer-Verlag London Ltd., part of Springer Nature
Induction of labor compared to expectant management in term nulliparas with a latent phase of labor of more than 8 hours: a randomized trial
No full textBackground: Prolonged latent phase of labor is associated with adverse maternal and neonatal outcomes. Preliminary data indicate that labor induction for prolonged latent phase may reduce cesarean delivery. We performed a study powered to Cesarean delivery to evaluate labor induction compared to expectant management in full term nulliparas hospitalized for persistent contractions but non-progressive to established labor after an overnight stay. Methods: From 2015 and 2017, nulliparas, ≥ 39 weeks' gestation with prolonged latent phase of labor (persistent contractions after overnight hospitalization > 8 h), cervical dilation ≤3 cm, intact membranes and reassuring cardiotocogram were recruited. Participants were randomized to immediate induction of labor (with vaginal dinoprostone or amniotomy or oxytocin as appropriate) or expectant management (await labor for at least 24 h unless indicated intervention as directed by care provider). Primary outcome measure was Cesarean delivery. Results: Three hundred eighteen women were randomized (159 to each arm). Data from 308 participants were analyzed. Cesarean delivery rate was 24.2% (36/149) vs. 23.3%, (37/159) RR 1.0 95% CI 0.7-1.6; P = 0.96 in induction of labor vs. expectant arms. Interval from intervention to delivery was 17.1 ± 9.9 vs. 40.1 ± 19.8 h; P < 0.001, intervention to active labor 9.6 ± 10.2 vs. 29.6 ± 18.5 h; P < 0.001, active labor to delivery 7.6 ± 3.6 vs. 10.5 ± 7.2 h; P < 0.001, intervention to hospital discharge 2.4 ± 1.2 vs. 2.9 ± 1.4 days; P < 0.001 and dinoprostone use was 19.5% (29/149) vs. 8.2% (13/159) RR 2.4 95% CI 1.3-4.4; P = 0.01 in IOL compared with expectant arms respectively. Intrapartum oxytocin use, epidural analgesia and uterine hyperstimulation syndrome, postpartum hemorrhage, patient satisfaction on allocated intervention, during labor and delivery and baby outcome were not significantly different across trial arms. Conclusions: Induction of labor did not reduce Cesarean delivery rates but intervention to delivery and to hospital discharge durations are shorter. Patient satisfaction scores were similar. Induction of labor for prolonged latent phase of labor can be performed without apparent detriment to expedite delivery. Trial registration: Registered in Malaysia National Medical Research Register (NMRR-15-16-23,886) on 6 January 2015 and the International Standard Randomised Controlled Trials Number registry, registration number ISRCTN14099170 on 5 Nov 2015. © 2019 The Author(s)
Standards of diagnostic colonoscopy for early‐stage neoplasia: Recommendations by an Asian private group
No full textBackground and Aim: In recent years, the incidence of colorectal cancer has been increasing, and it is now becoming the major cause of cancer death in Asian countries. The aim of the present study was to develop Asian expert-based consensus to standardize the preparation, detection and characterization for the diagnosis of early-stage colorectal neoplasia. Methods: A professional group was formed by 36 experts of the Asian Novel Bio-Imaging and Intervention Group (ANBI2G) members. Representatives from 12 Asia–Pacific countries participated in the meeting. The group organized three consensus meetings focusing on diagnostic endoscopy for gastrointestinal neoplasia. The Delphi method was used to develop the consensus statements. Results: Through the three consensus meetings with debating, reviewing the literature and regional data, a consensus was reached at third meeting in 2016. The consensus was reached on a total of 10 statements. Summary of statements is as follows: (i) Adequate bowel preparation for high-quality colonoscopy; (ii) Antispasmodic agents for lesion detection; (iii) Image-enhanced endoscopy (IEE) for polyp detection; (iv) Adenoma detection rate for quality indicators; (v) Good documentation of colonoscopy findings; (vi) Complication rates; (vii) Cecal intubation rate; (viii) Cap-assisted colonoscopy (CAC) for polyp detection; (ix) Macroscopic classification using indigocarmine spray for characterization of colorectal lesions; and (x) IEE and/or magnifying endoscopy for prediction of histology. Conclusion: This consensus provides guidance for carrying out endoscopic diagnosis and characterization for early-stage colorectal neoplasia based on the evidence. This will enhance the quality of endoscopic diagnosis and improve detection of early-stage colorectal neoplasia. © 2018 The Authors. Digestive Endoscopy published by John Wiley & Sons Australia, Ltd on behalf of Japan Gastroenterological Endoscopy Society