1,720,954 research outputs found
Surface Treatment of 316L stainless steel in the application of orthodontic miniscrews
No full text隨著矯正領域中骨性錨定的盛行,近年來有許多針對矯正用迷你骨釘的研 究,包括幾何形狀、材質或表面形貌的改質,期待能夠增加迷你骨釘的臨床使用 成功率。本研究從臨床的角度出發,希望針對台灣市面上盛行316L不�袗�矯正骨 釘的較高失敗率做改善,主要的研究目的在不改變316L不�袗�本質的前提下進行 表面改質,鍍上二氧化鈦的生物陶瓷膜,期待能提供物理性屏障提升抗腐蝕性並 與周圍骨頭有產生骨整合的可能,提高其生物相容性與骨整合能力,進而提升臨 床使用成功率。 本實驗選用316L不鏽鋼板來進行表面鍍膜作業,希望找出具有最佳機械性質 表現的鍍膜參數。本實驗的變數含以下三項:1. 鍍膜方式,以電子束蒸鍍法和溶 膠凝膠法方式製成二氧化鈦薄膜,2. 鍍膜厚度,選擇比較的厚度範圍為30~500 nm,3. 表面粗糙度。薄膜製成後,以場發射電子微探分析儀與X光繞射分析儀分 析薄膜表面組成與晶相,以場發射與掃瞄式電子顯微鏡觀察薄膜表面與截面,以 彩色三維雷射掃瞄儀分析薄膜表面粗糙度,並藉由刮痕測試機評估各種鍍膜參數 下的薄膜附著性,最後將所有結果與先前以磁控濺鍍鍍製的結果25作一綜合的比較。 實驗結果顯示:磁控濺鍍,離子束助鍍之電子束蒸鍍或溶膠凝膠法皆可製作 品質良好,結構緻密的二氧化鈦薄膜,其中磁控濺鍍鍍製薄膜附著性最好,並可 得金紅石結晶相,溶膠凝膠法鍍製薄膜附著性次之,高溫退火可得銳鈦礦結晶相, 電子束蒸鍍法鍍製薄膜附著性相對較差,且為無結晶相之二氧化鈦。薄膜附著性 隨厚度增加而增強,而鍍膜後試片表面的粗糙度並無明顯改變。With the advances of dental implants, temporary skeletal anchorage devices have now become established orthodontic anchorage aids and launched a new era for clinical orthodontic therapy. In recent years, numerous publications have investigated multiple factors affecting success rates of orthodontic mini-screws, such as shape design, material science, or surface topography. The success rate of 316L stainless steel orthodontic miniscrews was found to be lower than titanium alloy, and our research goal was to make surface modification by coating a TiO2 thin film on 316L stainless steel, which aimed to improve the biocompatibility and induce osseointegration. The 316L stainless steel plates were used in this study to test mechanical conditions. The experimental variables were included as follow: 1. Coating methods : ion-beam assisted electron beam evaporation and sol-gel method for titanium;2 Coating thickness, ranging from 30 to 500 nm; 3. Surface roughness. The composition and crystalline phase were analyzed by Energy Dispersive Spectrometer (EDS) and X-ray diffraction analyzer (XRD). The surface and cross-section of films were examined by scanning electron microscope. And the color three-dimensional laser scanning analyzer was used to analyze the surface roughness of films. Finally, the film adhesion under various coating parameters was evaluated by a scratch test machine. Besides, all the data would compare with the previous results of magnetron sputtering and produce a comprehensive view of those results. The study results showed that TiO2 thin film with good quality and dense structure can be coated on 316L stainless steel by magnetron sputtering, electron beam evaporation, and sol-gel method. The magnetron sputtering can produce best results regarding to film adhesion and crystallization structure. The sol-gel method also could produce thin film with good adhesion property and crystallization structure after rapid thermal annealing. However, the ion-beam assisted electron beam evaporation can produce thin film with dense structure, but the adhesion property was poorer than magnetron sputtering and sol-gel method. Besides, the film thickness played an important role in the adhesion property, and the surface roughness was not altered by the coating
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Study of the Success of Taiwanese Expatriate Managers on Overseas Assignments: A Grounded Theory Approach
Get PDFThe purpose of the study was to explore critical influences on expatriate performance during overseas assignments.
Multinational corporations (MNCs), in order to compete in today\u27s global economy, need to have trained professionals who can succeed as expatriates. However, what demands do such professionals face? The purpose of the study was to explore critical influences on expatriate performance during overseas assignments. Thirteen former Taiwanese expatriate managers from 5 Taiwan-based MNCs participated in the study. Data were gathered from in-depth interviews about the participants\u27 experiences during their overseas assignments. Through open, axial, and selective coding procedures associated with micro- and comparative analyses of a grounded theory research approach, a conceptual model explaining the nature of the success of expatriate managers on their out-of-home-country assignments was developed. Five major explanatory categories that were constructed from 11 propositions included competency, resistance to challenges, motivation, personality characteristics, and benefits for the professional and his organization. These results indicated that the identified competencies and characteristics complemented one another because they were all highly interrelated
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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