Effect of in-app components,medium, and screen size of electronic textbooks on reading performance,behavior, and perception

Although many app-based textbooks are available for students, reading have not been thoroughly outlined. This study aimed to understand how changes from paper to electronic textbooks have affected the academic reading task, investigate student users’ perceptions of in-app components and screen sizes, and identify issues affecting in-app components and task requirements. A mixed factorial design experiment was employed. Results showed that there were no significant changes in comprehension and time spent reading between print text and the iPad. Yet, student highlighting, notetaking, and reading behavior and perception significantly changed based on condition. In addition, students struggled to use in-app components and found them frustrating especially when accounting for sentence splitting. The findings presented can assist in understanding the changes in student reading behavior, which can be used to improve interface design of future e-textbooks.     

Promoting effects of pretreatment on Pd/CeO2 catalysts for CO oxidation

CeO₂ supported Pd catalysts were prepared in which the Pd species were presented in form of PdO and Ce_1-xPd_xO_2-δ solid solution. The Pd/CeO₂ catalysts were thermal treated for varying duration and its effect on Pd species was explored. The transformation of Pd species and redispersion were observed under oxidizing conditions at 500 °C. For catalyst treated with 10 h, more Pd ions penetrated into the CeO₂ matrix to form Ce_1-xPd_xO_2-δ solid solution, resulting in a 90% CO conversion at 84 °C after H₂ reduction. Another thermal treatment time extension led to an extraction of Pd from CeO₂ lattice in tandem with higher dispersion and smaller PdO particles on the surface, which was demonstrated by the results of XRD, ICP, TEM images, CO pulse adsorption and CO-TPR as a redispersion phenomenon.     

High-pressure phase behaviour of two poly-aromatic molecules in the presence of toluene and carbon dioxide

Asphaltene precipitation and deposition is a serious problem in oil recovery, oil transportation and refinery operations. Understanding of the phase behaviour of systems containing asphaltenes is very important to develop effective asphaltene deposition mitigation strategies. In order to get a better understanding of asphaltenes and in particular to get more insight in relations between molecular structural features and observed macroscopic behaviour, the phase behaviour of two poly-aromatic molecules (violanthrone-79 and hexa-tert-butylhexa-peri-hexabenzocoronene) was studied. Although both compounds do not represent all specific features of real asphaltenes, it is expected that to some extend they do. For instance, real asphaltenes are ill-defined mixtures and hard to characterize, while the selected poly-aromatic compounds form a well-defined system with toluene and CO₂. The poly-aromatic compounds were selected based on their molecular features and their tendency to self-assemble. The phase behaviour of solutions of these compounds in toluene was studied in the presence of different concentrations of carbon dioxide with a so-called Cailletet apparatus. The results in this work showed that the concentration of carbon dioxide affects the precipitation of the poly-aromatic compounds. At low concentration there is no precipitation, i.e., carbon dioxide acts as a co-solvent, while at higher concentration, carbon dioxide acts as an anti-solvent and the poly-aromatic molecule in the ternary system precipitates. As far as the phase behaviour is concerned, hexa-tert-butylhexa-peri-hexabenzocoronene resembles that of a real asphaltene.     

An investigation on effects of various parameters on viscosities of coal–water mixture prepared with Erzurum–Aşkale lignite coal

In this study the effects of parameters such as coal loading (wt.%), the initial pH of mixture, the addition of various electrolytes, surfactants and temperature on the viscosity and rheologic parameters of coal–water mixture (CWM) have been investigated. The apparent viscosity was measured with a RV8-Brookfield rotating type viscosimeter. The additives used were AlCl₃ and K₂HPO₄ as the electrolytes and Cetyltrimethyl Ammonium Bromide (CTAB), Sodium Dodecyl Sulphate (SDS) and Borrosperse NA-3A as the surfactants. It was found that the most effective additives, in terms of the viscosity reduction, were CTAB and K₂HPO₄, and that the CWM which had coal concentrations up to 50% (based on the weight of dry coal) could be prepared by using each additives. In addition, the viscosities of CWM with increasing temperature were found to increase at low speed, and decrease at high speed.     

Region based foreground segmentation combining color and depth sensors via logarithmic opinion pool decision

In this paper we present a novel foreground segmentation system that combines color and depth sensors information to perform a more complete Bayesian segmentation between foreground and background classes. The system shows a combination of spatial-color and spatial-depth region-based models for the foreground as well as color and depth pixel-wise models for the background in a Logarithmic Opinion Pool decision framework used to correctly combine the likelihoods of each model. A posterior enhancement step based on a trimap analysis is also proposed in order to correct the precision errors that the depth sensor introduces. The results presented in this paper show that our system is robust in front of color and depth camouflage problems between the foreground object and the background, and also improves the segmentation in the area of the objects’ contours by reducing the false positive detections that appear due to the lack of precision of the depth sensors.     

Development of carbon nanotubes reinforced hydroxyapatite composite coatings on titanium by electrodeposition method

Carbon nanotubes (CNTs) are outstanding reinforcement material for imparting strength and toughness to brittle hydroxyapatite (HAP). This work reports the electrodeposition of CNTs reinforced HAP on titanium substrate at −1.4 V vs. SCE during 30 min with the functionalised CNTs concentration ranging from 0 to 2 wt.%. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with energy dispersive X-ray analysis (EDX), high resolution transmission electron microscopy (HRTEM), mechanical and biological studies were used to characterise the coatings. Also, the corrosion resistance of the coatings was evaluated by electrochemical techniques in simulated body fluid (SBF) solution.     

Glycolytic Reprogramming in Silica-Induced Lung Macrophages and Silicosis Reversed by Ac-SDKP Treatment

Glycolytic reprogramming is an important metabolic feature in the development of pulmonary fibrosis. However, the specific mechanism of glycolysis in silicosis is still not clear. In this study, silicotic models and silica-induced macrophage were used to elucidate the mechanism of glycolysis induced by silica. Expression levels of the key enzymes in glycolysis and macrophage activation indicators were analyzed by Western blot, qRT-PCR, IHC, and IF analyses, and by using a lactate assay kit. We found that silica promotes the expression of the key glycolysis enzymes HK2, PKM2, LDHA, and macrophage activation factors iNOS, TNF-α, Arg-1, IL-10, and MCP1 in silicotic rats and silica-induced NR8383 macrophages. The enhancement of glycolysis and macrophage activation induced by silica was reduced by Ac-SDKP or siRNA-Ldha treatment. This study suggests that Ac-SDKP treatment can inhibit glycolytic reprogramming in silica-induced lung macrophages and silicosis.     

亚氯酸盐对大鼠仔鼠的运动神经毒理学影响

为研究二氧化氯在水消毒过程中的主要副产物——亚氯酸盐对人体健康的影响,通过前肌力测试、脑部解剖学观察等运动神经毒理项目的测试等研究手段,研究30、120和 360 mg/L的亚氯酸盐对3代Wistar大鼠仔鼠运动神经系统的毒性．结果表明:亚氯酸钠对Wistar大鼠仔鼠并未表现出明显的毒理学效应和剂量效应关系,但部分360 mg/L剂量组仔鼠小脑发生病变; 对于Wistar大鼠仔鼠运动神经发育无明显副作用的剂量值为30 mg/L,亚氯酸盐在饮用水中的最大污染水平目标值为1.1 mg/L．     

Novel interconnected nanochannel hydroxyapatite ceramics: synthesis,microstructure, and permeability

Uniform interconnected micro/nanoporous ceramics with good mechanical properties hold universal applications in biomedical and engineering fields. Herein, using hydroxyapatite (HAP) microtubes as the raw material instead of traditional particles, a novel interconnected nanochannel hydroxyapatite ceramic was fabricated successfully through one-step microwave sintering method without the addition of pore generators. The tubular structure of the HAP microtubes remains even after microwave sintering, which endows the ceramic with uniform interconnected nanochannels and 3-D porous structure. The HAP microtube nanochannel ceramic has a narrow pore size distribution from 400 nm to 600 nm, and exhibits well permeability, high adsorption/desorption ability. The porosity is about 30%, the HAP microtube nanochannel ceramic can be totally dyed by methylene blue within several minutes, and the blue dye can be desorbed completely in 45 min by ultrasonic vibration. In addition, due to the one-dimensional structure of the HAP microtubes, the HAP microtube nanochannel ceramic has smaller shrinkage, bigger porosity, and better toughness than the control sample fabricated by nanoparticles. Base on the uniform interconnected nanochannel structure, well permeability, high adsorption/desorption ability, the HAP microtube nanochannel ceramic fabricated here may be a promising candidate for many applications in biomedical engineering, environmental engineering, and energy engineering.