Influence of the relative molecular mass of viscosity enhancers on chloride diffusion in mortars: a preliminary study

Chloride diffusion in concrete is one of the key parameters of durability design for structure. Existing methods of reducing the chloride diffusion such as decreasing water-cement ratio and adding mineral admixtures often lead to increase the risk of concrete cracking. In this study, we focused on mitigating the permeation of chloride ions in concrete by adding viscosity enhancers to improve the viscosity of concrete pore solution, without densifying the pore structure of concrete. A comparative study was conducted among the conductivity of KCl solutions with the addition of polyethylene glycol (PEG) with 11 different relative molecular masses. The results show that the chloride diffusion can be most effectively reduced when the relative molecular mass remains in the range of 400-1500

[[alternative]]The effects of critical thinking instruction on critical thinking ability, problem solving and creativity for 5th grade students

[[abstract]]本研究旨在依據Ennis 批判思考的理論架構，編擬一套適合於國小高年級的批判思考 教學方案，並經由八週的實驗教學後，以探討批判思考教學方案，對國小學生批判思 考能力、問題解決能力及創造力之影響。 本研究採前後測控制組實驗設計，樣本取自台北市中山國小五年級學生43名，其中實 驗組為男生12名，女生9 名，共21名。控制組為男生12名，女生10名，共22名。實驗 組學生參加為期八週（每週一次，兩節課）的批判思考教學實驗，控制組則否。以康 乃爾批判思考測驗、問題解決測驗及威廉斯創造力測驗為評量工具，所得資料以單因 子共變數分析進行處理。 本研究主要結果如下： 一、批判思考教學活動設計對國小學生批判思考能力而言，實驗組的學童顯著優於控 制組。 二、批判思考教學活動設計對國小學生問題解決能力而言，實驗組的學童顯著優於控 制組。 三、批判思考教學活動設計對國小學生創造思考能力而言，實驗組的學童並未顯著優 於控制組。 綜合而言，批判思考教學活動設計能提高國小學生批判思考能力、問題解決能力；但 並不能增加學生之創造思考能力。 根據上述的發現，研究者提出批判思考教學在教育應用上的意義，及進一步研究的建 議。

Deterioration of organic coatings on concrete under artificial aging

The deterioration of organic coatings on concrete is closely linked to the efficiency in the protection process of reinforced structures. In the present work, polyurea resin and epoxy resin, which are widely used engineering coatings, were selected to measure and compare the performance under artificial aging. Fourier Transform infrared spectroscopy, water contact angle and scanning electron microscope were used to determine the deterioration of coatings. X-ray fluorescence method was used to measure chloride content passing through the coatings, which represent the efficiency of protection. Test results demonstrate that both deterioration and resistance to corrosion are important in assessment of the organic coatings under aging

In situ observation of tricalcium aluminate dissolution in water

The nanoscale dissolution flux of tricalcium aluminate (C3A) in flowing water is characterized in situ by Digital Holographic Microscopy (DHM). The pure dissolution of C3A in flowing water with a flow rate of 34 ml·min-1 before the precipitation of hydrated phases only lasted about one quarter of a second, and the pure dissolution rate mostly falls in the range of 500 ~ 1500 μmol·m-2·s-1. Subsequently, foil shape hydration product formed and rapidly covered the surface of C3A, leading to the dramatic decrease of the overall dissolution rate to 55 ± 10 μmol·m-2·s-1

Anti-inflammatory and antinociceptive effects of cordymin, a peptide purified from the medicinal mushroom Cordyceps sinensis

The anti-inflammatory and antinociceptive activities of cordymin, a peptide purified from the medicinal mushroom Cordyceps sinensis, were studied. The effects of cordymin on cytokine levels and total antioxidant activity were analysed. The antinociceptive effects of cordymin in vivo and in vitro were also determined. Cordymin treatment decreased the levels of tumour necrosis factor alpha, interleukin 1 beta and total antioxidant status. Cordymin inhibited the acetic acid-induced abdominal constrictions in mice in a dose-dependent manner. In the hot-plate test, results showed that cordymin significantly inhibited the reaction time to thermal stimuli at 30, 60 and 90 min. In neurolysin inhibition assay, cordymin showed strong activities against neurolysin (IC50 = 0.1 mu M). Our results show that cordymin is a potent anti-inflammatory and analgesic medicine

Surface characterization of AlGaN grown on Si (111) substrates

Up to 500 nm thick crack-free Al(0.25)Ga(0.75)N and Al(0.32)Ga(0.68)N epilayers have been grown on Si (111) substrates. The surface morphology of samples was investigated by an optical microscope and a scanning electron microscope (SEM). Pits and shale-like surface structure have been observed. XRD rocking curve measurements indicate the crystal quality of samples. The analyses show that the Al source flux is an important factor in growing AlGaN on Si (111). The information from the Micro-Raman spectra supported that Al atoms are gathered at nearby areas of the pits originated from the AlN/Si (111) interface in the initial stage of AlGaN growth. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved

Desiccation enhances phosphorylation of PSII and affects the distribution of protein complexes in the thylakoid membrane

Desiccation has significant effects on photosynthetic processes in intertidal macro-algae. We studied an intertidal macro-alga, Ulva sp., which can tolerate desiccation, to investigate changes in photosynthetic performance and the components and structure of thylakoid membrane proteins in response to desiccation. Our results demonstrate that photosystem II (PSII) is more sensitive to desiccation than photosystem I (PSI) in Ulva sp. Comparative proteomics of the thylakoid membrane proteins at different levels of desiccation suggested that there were few changes in the content of proteins involved in photosynthesis during desiccation. Interestingly, we found that both the PSII subunit, PsbS (Photosystem II S subunit) (a four-helix protein in the LHC superfamily), and light-harvesting complex stress-related (LHCSR) proteins, which are required for non-photochemical quenching in land plants and algae, respectively, were present under both normal and desiccation conditions and both increased slightly during desiccation. In addition, the results of immunoblot analysis suggested that the phosphorylation of PSII and LHCII increases during desiccation. To investigate further, we separated out a supercomplex formed during desiccation by blue native-polyacrylamide gel electrophoresis and identified the components by mass spectrometry analysis. Our results show that phosphorylation of the complex increases slightly with decreased water content. All the results suggest that during the course of desiccation, few changes occur in the content of thylakoid membrane proteins, but a rearrangement of the protein complex occurs in the intertidal macro-alga Ulva sp

MICROPLANKTON COMMUNITY DYNAMICS DURING THE ALGAE REMOVAL PROCESS FOR NUTRIENT CONTROL

In order to explore the possible impact of nutrient decrease on microplankton community under high eutrophication stress, rotifer, protozoa and algae samples were collected during a nutrient control from July to August, 2008 in Taihu Lake in China, and examined by both species and phylogenetic patterns. A total of 10 rotifer, 40 protozoal and 24 algal taxa were detected before the nutrient control in July, 2008. After the nutrient control (August, 2008), a total of 23, 16 and 9 taxa were detected for rotifer, protozoa and algae, respectively. By comparing samples to those before the control, the average Shannon-Wiener indexes, Simpson indexes and Pielou evenness indexes increased 197%, 101% and 73%, respectively. The average phylogenetic species variability (PSV) and phylogenetic species evenness (PSE) decreased 63% and 1%, respectively. Canonical correspondence analysis (CCA) of interactions between environmental variables and microplankton communities indicated that most of the microplankton species found in August were negatively correlated with nutrient level (e.g. total nitrogen, ammonia nitrogen, total phosphorus and orthophosphate), with both species and phylogenetic patterns. This study showed that the lower diversity and closer species relatedness of microplankton under high eutrophication stress could get mended when the nutrient got down. In addition, the results revealed that phylogenetic diversity patterns could effectively help community research when predicting community and species responses to disturbance.In order to explore the possible impact of nutrient decrease on microplankton community under high eutrophication stress, rotifer, protozoa and algae samples were collected during a nutrient control from July to August, 2008 in Taihu Lake in China, and examined by both species and phylogenetic patterns. A total of 10 rotifer, 40 protozoal and 24 algal taxa were detected before the nutrient control in July, 2008. After the nutrient control (August, 2008), a total of 23, 16 and 9 taxa were detected for rotifer, protozoa and algae, respectively. By comparing samples to those before the control, the average Shannon-Wiener indexes, Simpson indexes and Pielou evenness indexes increased 197%, 101% and 73%, respectively. The average phylogenetic species variability (PSV) and phylogenetic species evenness (PSE) decreased 63% and 1%, respectively. Canonical correspondence analysis (CCA) of interactions between environmental variables and microplankton communities indicated that most of the microplankton species found in August were negatively correlated with nutrient level (e.g. total nitrogen, ammonia nitrogen, total phosphorus and orthophosphate), with both species and phylogenetic patterns. This study showed that the lower diversity and closer species relatedness of microplankton under high eutrophication stress could get mended when the nutrient got down. In addition, the results revealed that phylogenetic diversity patterns could effectively help community research when predicting community and species responses to disturbance