Diamond-like carbon (DLC) is a metastable amorphous film that exhibits unique properties. However, a number of limitations exist regarding the use of DLC, for instance, its tribological characteristics. In this articl...Diamond-like carbon (DLC) is a metastable amorphous film that exhibits unique properties. However, a number of limitations exist regarding the use of DLC, for instance, its tribological characteristics. In this article, the fluorine and silicon incorporated diamond-like carbon (F-DLC and Si-DLC) films are studied, taking into account the tribological properties of these films compared with pure DLC. The structures of the films were characterized using Auger electron spectroscopy and Raman spectroscopy. The hardness and elastic modulus were evaluated by nanoindentation hardness testing. The friction behavior was assessed using ball-on-disk friction testing and optical microscopy. The results indicated that the deposited DLC films contained 0.6 - 2.1 at.% F and 26.7 - 38.4 at.% Si. A decrease in the hardness and elastic modulus was obtained as F increased in content, which was the opposite of the behavior observed in the Si-DLC films. This was due to the shifting in the G-peak position, which is related to the sp3 bonding fraction in the film. When measured in ambient air, the addition of Si into the DLC film strongly influenced the friction coefficient, whereas doping with F only slightly influenced the films, as evidenced by their wear scars. In addition, only a 26.7 at.% Si-DLC film showed a very low friction coefficient when measured in dry air. This was attributed to the formation of silicon-rich transfer layer on the ball surfaces. Therefore, the addition of Si with 26.7 at.% content to a DLC film can be considered beneficial for improving tribological performance.展开更多
The aim of this study is to assess creativity of the students from a project of first year undergrad students of King Mongkut’s University of Technology Thonburi,a residential college(KMUTT-RC).A project is a part of...The aim of this study is to assess creativity of the students from a project of first year undergrad students of King Mongkut’s University of Technology Thonburi,a residential college(KMUTT-RC).A project is a part of academic contents from Physics and Chemistry subjects.There were instructors from Chemistry,Physics,Engineering,and Social Sciences Department for consulting and engineering students for building a prototype.Formative assessment activity is explored from question,answer,and presentation.The characters,assessed on creativity,associated with an analysis on the rubric of prototype design,knowledge,and selective materials.Most students understood the perspective on creativity correlating with the observation from instructors.The instructor’s view represented that most of creative scores gained from motivate design and materials selection while their knowledge was not adequate.The accuracy of prototypes from the students did not relate to creativity in terms of design but error of measurement could occur from confusing with refractive index scale and from preparing a standard solution in chemical laboratory.展开更多
文摘Diamond-like carbon (DLC) is a metastable amorphous film that exhibits unique properties. However, a number of limitations exist regarding the use of DLC, for instance, its tribological characteristics. In this article, the fluorine and silicon incorporated diamond-like carbon (F-DLC and Si-DLC) films are studied, taking into account the tribological properties of these films compared with pure DLC. The structures of the films were characterized using Auger electron spectroscopy and Raman spectroscopy. The hardness and elastic modulus were evaluated by nanoindentation hardness testing. The friction behavior was assessed using ball-on-disk friction testing and optical microscopy. The results indicated that the deposited DLC films contained 0.6 - 2.1 at.% F and 26.7 - 38.4 at.% Si. A decrease in the hardness and elastic modulus was obtained as F increased in content, which was the opposite of the behavior observed in the Si-DLC films. This was due to the shifting in the G-peak position, which is related to the sp3 bonding fraction in the film. When measured in ambient air, the addition of Si into the DLC film strongly influenced the friction coefficient, whereas doping with F only slightly influenced the films, as evidenced by their wear scars. In addition, only a 26.7 at.% Si-DLC film showed a very low friction coefficient when measured in dry air. This was attributed to the formation of silicon-rich transfer layer on the ball surfaces. Therefore, the addition of Si with 26.7 at.% content to a DLC film can be considered beneficial for improving tribological performance.
文摘The aim of this study is to assess creativity of the students from a project of first year undergrad students of King Mongkut’s University of Technology Thonburi,a residential college(KMUTT-RC).A project is a part of academic contents from Physics and Chemistry subjects.There were instructors from Chemistry,Physics,Engineering,and Social Sciences Department for consulting and engineering students for building a prototype.Formative assessment activity is explored from question,answer,and presentation.The characters,assessed on creativity,associated with an analysis on the rubric of prototype design,knowledge,and selective materials.Most students understood the perspective on creativity correlating with the observation from instructors.The instructor’s view represented that most of creative scores gained from motivate design and materials selection while their knowledge was not adequate.The accuracy of prototypes from the students did not relate to creativity in terms of design but error of measurement could occur from confusing with refractive index scale and from preparing a standard solution in chemical laboratory.
