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Assessment feedback in examiner reports on master's dissertations in translation studies
No full textAssessment is a crucial part of degree programmes in higher education. While previous research has been primarily concerned with PhD thesis assessment practice in western countries, this article considers the focus and assessment criteria of 40 examiner reports on master's dissertations in translation studies at a Chinese university. The results indicate that these examiners structured their reports in four rhetorical moves: ‘preparing the candidate for a decision’, ‘expressing an evaluation’, ‘conveying the decision’, and ‘making recommendations’. These examiners appeared to place more emphasis on the expression of ideas, rather than on the accuracy and originality of those ideas. They apparently adopted flexible working criteria, assessing the dissertations based on institutional requirements and on their own experience. This article concludes with a discussion of implications for dissertation writing. © 2019 Elsevier Lt
Human serum albumin capsulated hydrophobic carbon nanodots as staining agent on HeLa tumor cell
No full textThe hydrophobic carbon nanodots (CDs) are promising nanoparticles to develop due to its uniformly size, good photoluminescence properties, and easy surface-modification. Highly photoluminescent hydrophobic CDs have been synthesized by carbonization of tartaric acid–L-tyrosine precursors. These hydrophobic CDs showed uniformly size distribution and exhibited strong–blue emission under UV irradiation. Further surface modification using human serum albumin (HSA) lead to the formation of hydrophilic CDs-HSA within low toxicity and good colloidal stability over varied pH and high ionic strengths. Various spectroscopies characterizations were done to analyze the morphological and chemical composition of both CDs and CDs-HSA. Further improvement analyses on cytotoxicity and confocal laser microscopy (CLSM) upon HeLa tumor cell suggested that the designed CDs-HSA was effective to be applied as staining agent against tumor cells. © 2019 Elsevier B.V
The effect of melatonin on delirium in hospitalised patients: A systematic review and meta-analyses with trial sequential analysis
No full textObjectives: Melatonin is an endogenous hormone, which regulates circadian rhythms and promotes sleep. In recent years, several randomised controlled trials examining the prophylactic use of melatonin to prevent delirium were published with conflicting findings. The primary aim of this review was to determine the effect of melatonin on the incidence of delirium in hospitalised patients. Data sources: MEDLINE, EMBASE and CENTRAL were systematically searched from their inception until December 2018. Review methods: All randomised clinical trials were included. Results: Sixteen trials (1634 patients) were included in this meta-analysis. Incidence of delirium was not significantly lower in patients who received melatonin, with an odd ratio, OR (95%Cl) of 0.55 (0.24–1.26); ρ = 0.16, certainty of evidence = low, trial sequential analysis = inconclusive. However, patients who randomised to melatonin had a significantly shorter length of stay in intensive care units, with a mean difference, MD (95%CI) of −1.84 days (−2.46, −1.21); ρ < 0.001. No differences were demonstrated in the need for physical restraints (OR 95%Cl 0.65; 0.31–1.37; ρ = 0.26) and the requirement of sedative agents (OR 95%Cl 0.86; 0.48–1.55; ρ = 0.62). Conclusions: In summary, the results of this meta-analysis of sixteen trials neither support nor oppose the use of melatonin in the prevention of delirium of hospitalised patients. We identified high heterogeneity across all the included trials and low certainty of evidence with potential type II error. Future multi-centre, adequately powered randomised controlled trials are warranted to provide more certainty on the use of melatonin for the prevention of delirium. PROSPERO: CRD42019123546. © 2019 Elsevier Inc
Temperature and doping effects on the transport properties of SrIn2P2 Zintl compound
No full textIn this paper, we present and discuss temperature and doping effects on the electrical and thermal transport properties of SrIn2P2 Zintl phase along the [100] and [001] crystallographic directions. The calculations were performed by using the full-potential linearized augmented plane wave method in conjunction with Boltzmann's transport theory and Bardeen-Shockley's deformation potential with the carrier relaxation time and effective mass approximations. We calculated the band effective masses inside two energy windows of 125 meV; one above the fundamental conduction band minimum (FCBM) and the second below the valence band maximum (VBM). The calculated band effective masses exhibit a noticeable anisotropy and demonstrate that the n-type SrIn2P2 transport properties are better than those of the p-type one over the considered charge-carrier concentration range at room-, intermediate- and high-temperature, due to the proximity of the secondary conduction band minimums to the FCBM (∼58 meV). The n-type SrIn2P2 has a considerable Seebeck coefficient (429 μV/K), an extremely low electrical resistivity (0.90 mΩcm), and a relatively small lattice thermal conductivity (1.12 Wm−1K−1), which yield a figure of merit ZT of 0.87 for an electron concentration of 3.0 × 1019 cm−3 at 900 K. These results make SrIn2P2 a hopeful n-type thermoelectric material if we can further reduce its lattice thermal conductivity. © 2019 Elsevier B.V
Generation of Q-switched and mode-locked pulses with Eu2O3 saturable absorber
No full textIn this paper, Europium Oxide (Eu2O3) is used as a saturable absorber (SA) to produce Q-switched and mode-locked pulses in an erbium-doped fiber laser (EDFL) cavity. The Eu2O3 was synthesized using casting technique and the resulting Eu2O3 thin film was introduced between two optical fiber ferrule connectors to form a SA. Then the SA was positioned in the EDFL ring cavity. A stable Q-switched operation was achieved by controlling the loss and gain of the cavity. As the pumping power was increased from 84.0 mW to 125.0 mW, the repetition frequency increased from 60.1 kHz to 68.6 kHz and pulse width reduced from 4.5 μs to 3.6 μs respectively. The Q-switched EDFL was operating at the center wavelength of 1568 nm, had a 162 nJ maximum pulse energy and 10.24% slope efficiency. Adding a 100 m SMF in the ring cavity initiated a self-starting mode-locked EDFL and the pulses remained stable within a range of 104.6 to 145.8 mW pump power. At the threshold pump power of 104.6 mW, the mode-locked EDFL operated at a central wavelength of 1565 nm with a repetition rate of 1.8 MHz and a pulse width of 3.51 ps. The results show that Eu2O3 can be deployed as a SA for both Q-switching and mode locking generations. © 2020 Elsevier Lt
Effects of temperature and dark fermentation effluent on biomethane production in a two-stage up-flow anaerobic sludge fixed-film (UASFF) bioreactor
No full textIn a two-stage of up-flow anaerobic sludge fixed-film (UASFF) bioreactor, palm oil mill effluent (POME) wastewater was used as inoculum and substrate to study the biodegradation in association with hydrogen and methane production. During the first stage (H2-UASFF unit), different temperatures (37–70 °C) and hydraulic retention time (HRT) was designed and analyzed using response surface methodology (RSM) for biohydrogen production. In the second stage (CH4-UASFF unit), at 24 h HRT, a continuous experiment was carried out using the same temperature and effluent from H2-UASFF unit (also known as dark fermentation effluent) was used as substrate (12–20 g COD L−1). This study is focusing on the second stage of UASFF bioreactor (i.e. CH4-UASFF) for biomethane production. Studied parameters were designed using Historical Data in RSM. Its effects on methane production rate (MPR), methane yield, biogas percentage and COD removal were analyzed. The relation between initial effluent COD and temperature on biomethane production and overall reactor performance treating POME wastewater were also examined. Results showed that 76% of total COD removal efficiency (TCOD) was achieved using two-stage UASFF bioreactor. The MPR of 15.63 L CH4 d−1, methane yield of 0.803 L CH4 g−1 CODrem.d−1, COD removal efficiency of 66.28% and 93.31% of CH4 at optimum temperature and effluent COD of 54 °C and 12 g COD L−1, respectively were obtained in CH4-UASFF unit. Based on this study, thermophilic temperature and low POME concentration showed a significant impact on biomethane production and more than 70% of TCOD of POME was reduced at 24 h HRT. © 2019 Elsevier Lt
Q-switched and mode-locked erbium-doped fiber laser using gadolinium oxide as saturable absorber
No full textQ-switched and mode-locked Erbium-doped fiber lasers (EDFLs) were demonstrated using gadolinium oxide (Gd2O3) as a saturable absorber. The Gd2O3 nano-powder was embedded into polyvinyl alcohol (PVA) film and integrated into the EDFL cavity to achieve both lasers. At first, a stable Q-switched laser was realized at a center wavelength of 1564.1 nm. The repetition rate increased from 78 to 90.74 kHz and the pulse width reduced from 5.68 to 4.68 µs as the pump power adjusted within 96.28 to 147.16 mW. The output power increased steadily from 19.3 to 26.4 mW as the pump power was raised from 96.28 to 147.16 mW. The slope efficiency of the output power was 14%. Later, a 100 m single mode fiber was incorporated into the similar laser cavity to generate a stable mode-locked laser at a threshold pump power of 96.28 mW with a central wavelength of 1561.5 nm. We observed a stable repetition rate of 1.907 MHz with a pulse width of 3.82 ps as the pump power raised from 96.28 to 147.16 mW. The peak power obtained from the mode-locked laser was tunable from 1.78 to 2.58 kW as the pump power was adjusted from minimum to the maximum. These results indicate the outstanding performance of Gd2O3 SA for both Q-switching and mode-locking applications. The lasers are useful for various applications including, micromachining of material, frequency comb-generation and remote sensing. © 2020 Elsevier Inc
Multi-objective optimization of all-wheel drive electric formula vehicle for performance and energy efficiency using evolutionary algorithms
No full textA new method based on constraint multi-objective optimization using evolutionary algorithms is proposed to optimize the powertrain design of a battery electric formula vehicle with an all-wheel independent motor drive. The electric formula vehicle has a maximum combined motor power of 80 kW, which is a constraint for delivering maximum vehicle performance with minimal energy consumption. The performance of the vehicle will be simulated and measured against different driving events, that is, acceleration event, autocross event, and endurance event. Each event demands a different aspect of performance to be delivered by the motor. The respective event lap time or energy rating will be measured for performance assessment. In this study, a non-dominated sorting genetic algorithm II and constrained multi-objective evolutionary algorithm based on decomposition by using differential evolution are employed to optimize the motor transmission ratio, motor torque scaling, and downforce scale of both front and rear wheels against the acceleration event to minimize energy consumption and event lap time while constraining the combined motor power of all wheels to not exceed 80 kW. The optimization will be performed through software-in-the-loop between MATLAB and VI-Grade, where the high-fidelity vehicle will be modeled in VI-Grade and optimization algorithms will be implemented on the host in MATLAB. Results show that the non-dominated sorting genetic algorithm II outperforms the constrained multi-objective evolutionary algorithm based on decomposition by using differential evolution in obtaining a wider distributed Pareto solution and converges at a relatively shorter time frame. The optimized results show a promising increase in the performance of the electric formula vehicle in completing those events with the highest combined performance scoring, that is, the lap time of acceleration events improves by 9.18%, that of autocross event improves by 6.1%, and that of endurance event improves by 4.97%, with minimum decrease in energy rating of 32.54%. © IMechE 2019
Poly(cyclodextrin-ionic liquid) based ferrofluid: A new class of magnetic colloid for dispersive liquid phase microextraction of polycyclic aromatic hydrocarbons from food samples prior to GC-FID analysis
No full textPoly(β-cyclodextrin-ionic liquid) grafted magnetic nanoparticles combined with 1-octanol as supramolecular solvents (SUPRASs) presenting new ferrofluid was developed and successfully applied in the dispersive liquid-phase microextraction of seven representative polycyclic aromatic hydrocarbons. One variable at-a-time (OVAT) analysis and response surface methodology (RSM) were used for efficient optimization of the main variables. The calibration curves were found to be linear in the range of 0.1–150 ng mL−1 with correlation of determinations (R2) ranging from 0.9944 to 0.9986. Detection limits ranged at 0.02–0.07 ng mL−1 for all studied PAHs. The intra and inter-day precision values (RSD %) were in the range of 1.80%–7.56% and 2.97%–8.23%, respectively. The ferrofluid showed a satisfactory reproducibility between 1.72% and 5.90%, and acceptable recovery values at 84%–110% were obtained for the real samples analysis. The optimized method was successfully applied to access the content safety of the PAHs studied in a variety of commercial food and beverages available in Malaysia. © 2020 Elsevier Lt
Enhancing efficiency of dye sensitized solar cells based on poly(propylene) carbonate polymer gel electrolytes incorporating double salts
No full textThe performance of dye-sensitized solar cells (DSSCs) depends on the ionic conductivity and flexibility of electrolyte. Gel polymer electrolytes (GPEs) consisting poly(propylene) carbonate (PPC) incorporated with double salts (i.e. calcium iodide (CaI2) and tetrabutylammonium iodide (TBAI)) were prepared. X-ray diffraction (XRD) authenticated that the crystallinity of PPC is mitigated after incorporation of different concentrations of CaI2 and TBAI, which is favourable for ion transportation. Fourier-transform infrared spectroscopy (FTIR) unveils the occurrence of complexation between PPC and the double salts. GPE containing 10% of CaI2 and 30% of TBAI exhibits the highest ionic conductivity (1.838 mS cm−1) with the activation energy of 0.156 eV. The fabricated DSSC employing the optimized GPE exhibits the energy conversion efficiency (η) of 5.49%, short circuit current density (Jsc) of 16.6 mA cm−2, open circuit voltage (Voc) of 0.568 V and fill factor (FF) of 54%. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature