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Enhancing the performance of vanadyl phthalocyanine-based humidity sensor by varying the thickness
No full textThe effect of various active layer thicknesses (approximately 66, 80 and 90 nm) was studied on the electrical properties of a vanadyl 3,10,17,24-tetra-tert-butyl-1,8,15,22-tetrakis(dimethylamino)-29H,31H-phthalocyanine (VTP)-based capacitive humidity sensor. Along with that, characterization of the structural and film wettability are being sought to ensure that the mechanism of humidity sensing properties in the sensor is well understood, allowing a controlled production situation to be established. Using the solution processed spin coating, the sensor devices have been fabricated in the planar geometry of Al/VTP/Al, with the capacitance as a function of relative humidity levels of 1 V input. In the present study, the device with the thinnest (66 nm) VTP film has been shown to possess optimized performance with a maximum sensitivity of 9.2 pf/%RH at 500 Hz than that of thicker (80 and 90 nm) VTP films. The sensitivity of the VTP-based sensor with the thickness of approximately 80 and 90 nm are reduced to 7.7 pf/%RH and 2.55 pf/%RH, respectively
PAPR reduction in all-optical OFDM based on time interleaving odd and even subcarriers
No full textIn this paper, a new all-optical approach for reducing peak-to-average power ratio (PAPR) in all-optical orthogonal frequency division multiplexing (AO-OFDM) system based on time interleaving odd and even subcarriers (TIOES) is proposed and analytically modeled. In this approach, all subcarriers are initially modulated with higher modulation format such as m-array quadrature amplitude modulation (mQAM) and encoded by return-to-zero (RZ) coder. Then, odd and even subcarriers are temporally interleaved. An analytical model for estimating the impact of the interleaved time on PAPR reduction and induced nonlinear phase noise (NPN) is developed. The effect of reducing PAPR on performance of AO-OFDM system is also numerically investigated using VPItransmissionMaker® commercial software. This system utilizes an optical coupler-based inverse fast Fourier transform/fast Fourier transform. The results reveal that minimum PAPR is occurred when interleaved time between odd and even subcarriers equal to half symbol duration where the PAPR has been reduced by 3 dB. In addition, by employing proposed technique, the signal to noise ratio (SNR) is improved by about 2.5 dB at transmission distance of 800 km as compared with 4QAM AO-OFDM without PAPR technique
Evaluation of novel Parkinson's disease candidate genes in the Chinese population
No full textRecent whole-exome sequencing studies in European patients with Parkinson's disease (PD) have identified potential risk variants across 33 novel PD candidate genes. We aim to determine if these reported candidate genes are similarly implicated in Asians by assessing common, rare, and novel nonsynonymous coding variants by sequencing all 33 genes in 198 Chinese samples and genotyping coding variants in an independent set of 9756 Chinese samples. We carried out further targeted sequencing of CD36 in an additional 576 Chinese and Korean samples. We found that only 8 of 43 reported risk variants were polymorphic in our Chinese samples. We identified several heterozygotes for rare loss-of-function mutations, including the reported CD36 p.Gln74Ter variant, in both cases and controls. We also observed 2 potential compound heterozygotes among PD cases for rare loss-of-function mutations in CD36 and SSPO. The other reported variants were common in East Asians and not associated with PD, completely absent, or only found in controls. Therefore, the 33 reported candidate genes and associated variants are unlikely to confer significant PD risk in the East Asian population
AC susceptibility and electrical properties of rare-earth- and alkali metal-substituted (Tl0.7M0.3)Sr2CaCu2O7 with M = Er, Gd, La, Na, K and Rb
No full textThe effects of rare-earth elements M = Er, Gd and La, and alkali metals M = Na, K and Rb substitution on (Tl0.7M0.3)Sr2CaCu2O7 (Tl-1212) are reported. The rare-earth elements were chosen by considering the ionic radius, i.e., from the smallest (Er+3) to the largest (La+3) ion. The samples were prepared via the solid-state reaction method. X-ray diffraction patterns showed the presence of major Tl-1212 and minor Tl-1201 and Ca0.3Sr0.7CuO2 phase in almost all samples. The resistance versus temperature curves for the rare-earth-substituted samples showed onset temperature between 87 and 90 K and zero resistance temperature between 69 and 81 K. Alkali metal substitutions exhibited Tl-1212 phase but showed no superconducting transition although the electrical resistivity was much lower than the rare-earth-substituted samples. AC susceptibility measurement showed superconducting transition Tcχ, between 59 and 80 K for the rare-earth element-substituted samples. The average grain size, the transition temperature, Tcχ and the peak temperature Tp of the imaginary part of the susceptibility χ″ decreased as the ionic radius of the rare earths was reduced
Identification of significant features and data mining techniques in predicting heart disease
No full textCardiovascular disease is one of the biggest cause for morbidity and mortality among the population of the world. Prediction of cardiovascular disease is regarded as one of the most important subject in the section of clinical data analysis. The amount of data in the healthcare industry is huge. Data mining turns the large collection of raw healthcare data into information that can help to make informed decision and prediction. There are some existing studies that applied data mining techniques in heart disease prediction. Nonetheless, studies that have given attention towards the significant features that play a vital role in predicting cardiovascular disease are limited. It is crucial to select the correct combination of significant features that can improve the performance of the prediction models. This research aims to identify significant features and data mining techniques that can improve the accuracy of predicting cardiovascular disease. Prediction models were developed using different combination of features, and seven classification techniques: k-NN, Decision Tree, Naive Bayes, Logistic Regression (LR), Support Vector Machine (SVM), Neural Network and Vote (a hybrid technique with Naïve Bayes and Logistic Regression). Experiment results show that the heart disease prediction model developed using the identified significant features and the best-performing data mining technique (i.e. Vote) achieves an accuracy of 87.4% in heart disease prediction
Tunable Q-switched erbium-doped fiber laser in the C-band region using nanoparticles (TiO2)
No full textA tunable, passively Q-switched fiber laser using titanium dioxide (TiO2) as saturable absorber (SA) is proposed and demonstrated. The TiO2 SA has an insertion loss and modulation depth of 2.6 dB and 19.1 % respectively. The generated laser output has a repetition rate of 83.3 kHz and pulse-width of 0.08 μs at a maximum pump power of 270.0 mW. On the other hand, tuning the operational wavelength from 1534.0 nm to 1570 nm while fixing the pump power at 70.0 mW varies the repetition rate and pulse width from 50.5 to 22.2 kHz and 1.3 to 2.7 μs respectively. The results indicate that TiO2 could be an inexpensive and efficient SA for generating passively Q-switched fiber laser
Application of MoWS2-rGO/PVA thin film as all-fiber pulse and amplitude modulators in the O-band region
No full textIn this work, a MoWS2-rGO/PVA thin film is fabricated and its applications as in amplitude modulation are demonstrated. Embedded in a praseodymium fluoride fiber laser cavity, the MoWS2-rGO/PVA thin film is able to induce pulsing in the laser output, which operates in the O-band region. As an optical amplitude modulator, the MoWS2-rGO/PVA thin film is capable of achieving a modulation efficiency of 0.17 dB/mW in the O-band region over a pump power range of 46.0 mW to 78.5 mW. C-band and L-band operation is also demonstrated, with modulation efficiencies of 0.30 dB/mW and 0.15 dB/mW, respectively over pump power ranges of 3.51 mW–52.17 mW and 24.4 mW–61.3 mW. This work can be improved by further engineering the composition ratio of the alloy material to enhance the modulation efficiency for both pulsed and amplitude modulations, giving rise to various applications, in particular in bio-medicine and manufacturing
Pyro-lytic de-oxygenation of waste cooking oil for green diesel production over Ag2O3-La2O3/AC nano-catalyst
No full textGreen diesel derived from deoxygenation technology has been developed to replace instability of fatty acid alkyl ester (biodiesel) due to the presence oxygenated species. Herein, the green diesel was synthesized via catalytic deoxygenation (DO) of waste cooking oil (WCO) over synthesized Ag2O3–La2O3/ACnano catalyst under hydrogen-free environment. Based on the study, the effect of silver (Ag) species (10–30 wt%) towards DO reactivity and product distribution was investigated. It was revealed that the Ag2O3(10%)–La2O3(20%)/ACnano formulation resulted in a higher yield (∼89%) of liquid hydrocarbons with majority of diesel fractions selectivity (n–(C15+C17) at ∼93%. In addition, decarboxylation and decarbonylation reaction processes of the WCO to DO was promoted by the presence of acid and basic active sites on Ag2O3(10%)–La2O3(20%)/ACnano catalyst. The high stability of the Ag2O3(10%)–La2O3(20%)/ACnano catalyst was proven by maintenance of six continuous runs with constant yield (>80%) of hydrocarbons and (>93%) selectivity of n–(C15+C17) under mild reaction conditions
Optimisation of biomass, exopolysaccharide and intracellular polysaccharide production from the mycelium of an identified Ganoderma lucidum strain QRS 5120 using response surface methodology
Get PDFWild-cultivated medicinal mushroom Ganoderma lucidum was morphologically identified and sequenced using phylogenetic software. In submerged-liquid fermentation (SLF), biomass, exopolysaccharide (EPS) and intracellular polysaccharide (IPS) production of the identified G. lucidum was optimised based on initial pH, starting glucose concentration and agitation rate parameters using response surface methodology (RSM). Molecularly, the G. lucidum strain QRS 5120 generated 637 base pairs, which was commensurate with related Ganoderma species. In RSM, by applying central composite design (CCD), a polynomial model was fitted to the experimental data and was found to be significant in all parameters investigated. The strongest effect (p < 0.0001) was observed for initial pH for biomass, EPS and IPS production, while agitation showed a significant value (p < 0.005) for biomass. By applying the optimized conditions, the model was validated and generated 5.12 g/L of biomass (initial pH 4.01, 32.09 g/L of glucose and 102 rpm), 2.49 g/L EPS (initial pH 4, 24.25 g/L of glucose and 110 rpm) and 1.52 g/L of IPS (and initial pH 4, 40.43 g/L of glucose, 103 rpm) in 500 mL shake flask fermentation. The optimized parameters can be upscaled for efficient biomass, EPS and IPS production using G. lucidum
Valuation of enterprise risk management in the manufacturing industry
No full textThe paper examines the valuation of enterprise risk management (ERM) through its effects on firm cost and efficiency. Consistent with the empirical evidence, ERM is found to benefit larger firms by reducing earning variability and providing higher returns on equity. The results suggest significant evidence of a value premium attached to effective ERM programmes. It is found that an effective ERM programme adds value to manufacturing firms by mitigating firm cost and enhancing firm efficiency. The results also suggest that the strong valuation effects of ERM are associated with cost management, inventory management, asset management, and cash flow management in China