Using a wiki-based collaborative process writing pedagogy to facilitate collaborative writing among Chinese primary school students

This case study explored collaborative writing in Chinese among 59 primary four Chinese students using a Wiki-based Collaborative Process Writing Pedagogy (WCPWP) in Shenzhen, China. It aimed mainly to design and orchestrate a WCPWP in order to facilitate students' Chinese writing. It investigated students' collaborative writing process and their performance on a wiki, and explored the perceptions and attitudes of the teacher and her students towards WCPWP. A wiki-based writing environment named Joyous Writing Club (JWC) was designed and developed using MediaWiki software. Data was collected from questionnaires, online wiki documents, interviews, and observations. The results illustrated students' collaborative writing process and their products on the wiki. Besides, the results showed that students perceived WCPWP was beneficial in boosting writing motivation, increasing group interactions, and extending the audience for their writing. This study may help primary educators gain a deeper understanding of the relationships between technology, pedagogy and education. It may also provide practical recommendations for primary school Chinese language teachers in the integration of Web 2.0 tools (wikis, Google Docs) as well as the use of effective pedagogical strategies in the teaching of Chinese writing.published_or_final_versio

Students and teacher’s attitudes and perceptions toward collaborative writing with WIKI in a Primary Four Chinese classroom

This case study investigated the attitudes and perceptions of primary school students and their teacher toward collaborative writing using a wiki technology in a Chinese writing class in China. An online collaborative writing environment named “Joyous Writing Club”(JWC) was designed and developed using a wiki. Participants included 59 primary four students and their Chinese language teacher. The study adopted a mixed-methods design, using quantitative and qualitative data. A writing attitude test was administered to the students using a pretest-posttest design, and JWC was used by the participants for a period of two months. After that, a questionnaire using responses on a 5-point Likert scale was administered to examine the students’ perceptions on the use of the wiki-based collaborative writing environment. A questionnaire consisting of open-ended queries was also administered to the teacher to gain her insights on using JWC with her students. The results indicated that students showed improvement in writing attitudes after engaging in collaborative writing with wiki. Students’ responses to the questionnaire revealed that they perceived the collaborative writing using a wiki as beneficial in facilitating motivation to write, heightened group interactions, and widening the reading audience of their writings. Students’ positive perceptions on the use of JWC were also found to associate positively with students’ writing attitudes in the posttest. The strongest positive correlation was found between perceptions on motivation to write and writing attitudes. The teacher reported that students expressed higher interest in writing on JWC compared relative to writing on paper. She also indicated that factors such as the topic of the Chinese composition and students’ computer skills may affect the quality of collaborative writing with wiki. This study provides information that may help teachers and researchers to understand students’ responses towards collaborative writing with a wiki environment in a Chinese writing class, and the factors that may facilitate the effective use of such wiki environment.postprin

On pairwise comparison matrices that can be made consistent by the modification of a few elements

Pairwise comparison matrices are often used in Multi-attribute Decision Making forweighting the attributes or for the evaluation of the alternatives with respect to a criteria. Matrices provided by the decision makers are rarely consistent and it is important to index the degree of inconsistency. In the paper, the minimal number of matrix elements by the modification of which the pairwise comparison matrix can be made consistent is examined. From practical point of view, the modification of 1, 2, or, for larger matrices, 3 elements seems to be relevant. These cases are characterized by using the graph representation of the matrices. Empirical examples illustrate that pairwise comparison matrices that can be made consistent by the modification of a few elements are present in the applications

Improved corrosion resistance of plasma carbon coated NiTi orthopedic materials

Nickel titanium (NiTi) alloys are useful in orthopedic applications because of their super-elastic properties and shape memory effects. However, when NiTi is used for a prolonged period of time, harmful Ni ions can leach out into the surrounding body fluid inside a human body, and so it is important to design a method to impede the out-diffusion of nickel from the materials into the biological medium. We aim at producing a barrier to mitigate the release of Ni ions during normal use. Carbon coatings have been shown to possess excellent bio-compatibility and good mechanical strength. In this work, amorphous hydrogenated DLC films with a graded C/NiTi interface were fabricated by plasma immersion ion implantation & deposition (PU & D) to provide such a barrier layer on NiTi. The elemental depth profiles and film thickness were determined by X-ray photoelectron spectroscopy (XPS) whereas the surface morphology was evaluated using atomic force microscopy (AFM). The film structure was studied by X-ray diffraction (XRD) and Raman spectroscopy. The corrosion resistance of the film was investigated using electrochemical tests based on ASTM G5-94. Compared to the control sample, the corrosion potential of the sample with the carbon coating changes from -250 to -50 mV and the film breakdown potential increases from 250 to 1200 mV. The corrosion current also diminishes from 10-6 to 10-7 A. The simulated body fluid (SBF) solutions after the electrochemical test were analyzed for Ni concentrations by inductively-coupled plasma mass spectrometry (ICPMS) and that data show that a much smaller amount of Ni has been released from the treated sample surface compared to the untreated control sample surface. Our results thus indicate that the deposited DLC film is effective in retarding the release of Ni ions from the bulk materials and more superior corrosion resistance is achieved based on our tests in a simulated fluid medium and at human body temperature.published_or_final_versio

Suppression of nickel out-diffusion from porous nickel-titanium shape memory alloy by plasma immersion ion implantation

Summary form only given. Porous nickel titanium is a promising material for medical application not only because of its super elasticity and shape memory effect but also the porous structure which may enhance bone growth due to the increased surface area. It is thus especially suitable for bone tissue in-growth and fixation of biomedical implants. However, like its dense counterpart, Ni leaching from the materials causes health concern. Thus, in order to suppress Ni diffusion from the materials to body fluids and tissues in humans, a diffusion barrier or similar structure must be introduced. In this work, we produced this diffusion barrier layer by oxygen or nitrogen plasma immersion ion implantation (PIII). In vitro tests were conducted by immersing the plasma-treated NiTi into simulated body fluid (SBF) at 37plusmn0.5degC for 5 weeks and the resulting SBF was analyzed for Ni and Ti using inductively-coupled plasma mass spectrometry (ICMPS). Our results show that Ni leaching is significantly mitigated by both nitrogen and oxygen PIII.published_or_final_versio

Nickel suppression in Ni-Ti alloys by plasma immersion ion implantation surface treatment: New materials for orthopaedic implantation

Conference Theme: Spinal Motion Segment: From Basic Science to Clinical Applicationpublished_or_final_versio

Nickel ion level in scoliotic patients implanted with nitrogen plasma surface modified nickel-titanium superelastic spinal implant

published_or_final_versionThe 3rd International NanoElectronics Conference (INEC), Hong Kong, 3-8 January 2010. In Proceedings of the 3rd INEC, 2010, p. 136

Suppression of nickel release in nickeltitanium alloys by plasma immersion ion implantation surface treatment: towards a new generation of "smart" orthopaedic implants

Summary form only given. Nickel-titanium shape memory alloys (NiTi) are potentially very useful in spinal deformity correction due to their super elastic properties and their ability to change shape with temperature. However, release of toxic nickel particulate debris remains a major concern. We have developed a novel method of altering the surface of the material to reduce nickel release by using plasma immersion ion implantation (PIII). This study compares the corrosion resistance and mechanical properties of PIII treated samples with untreated NiTi. NiTi discs containing 50.8% Ni were implanted with nitrogen using PIII technique. Their elemental depth profile, surface chemical composition, surface hardness and corrosion resistance were compared with untreated NiTi. The amount of Ni released into simulated body fluids after the accelerated corrosion tests were determined. The biocompatibility was assessed by culturing mouse osteoblasts expressing an enhanced green fluorescent protein on the surface of these materials. After PIII treatment, a layer of titanium nitride formed on the surface. Compared to untreated NiTi, the corrosion resistance is better by five times, and the surface hardness and elastic modulus are better by a factor of 2. The concentration of Ni in the simulated body fluid for the untreated sample was 30 ppm compared to undetectable levels in the PIII treated sample. There was no difference in the ability of cells to grow on either surface. PIII results in enhanced corrosion and wear resistance, and negligible Ni release. This technique will allow NiTi alloys to be safely implanted in the human body. A new generation of "smart" orthopaedic implants will likely result.published_or_final_versio

Methylation of miR-155-3p in mantle cell lymphoma and other non-Hodgkin's lymphomas

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New plasma surface-treated memory alloys: Towards a new generation of "smart" orthopaedic materials

This paper describes the corrosion resistance, surface mechanical properties, cyto-compatibility, and in-vivo performance of plasma-treated and untreated NiTi samples. Nickel-titanium discs containing 50.8% Ni were treated by nitrogen and carbon plasma immersion ion implantation (PIII). After nitrogen plasma treatment, a layer of stable titanium nitride is formed on the NiTi surface. Titanium carbide is also found at the surface after carbon plasma implantation. Compared to the untreated samples, the corrosion resistances of the plasma PIII samples are better by a factor of five and the surface hardness and elastic modulus are better by a factor of two. The concentration of Ni leached into the simulated body fluids from the untreated samples is 30 ppm, whereas that from the plasma-treated PIII are undetectable. Although there is no significant difference in the ability of cells to grow on either surface, bone formation is found to be better on the nitrogen and carbon PIII sample surfaces at post-operation 2 weeks. All these improvements can be attributed to the formation of titanium nitride and titanium carbide on the surface. © 2007 Elsevier B.V. All rights reserved.postprin