Kun Shan University

About: Kun Shan University is a education organization based out in Tainan City, Taiwan. It is known for research contribution in the topics: Heat transfer & Thin film. The organization has 1992 authors who have published 2928 publications receiving 45685 citations. The organization is also known as: Kūnshān Kējì Dàxué.

Multiobjective process optimisation for turning of tool steels

Abstract: A simple methodology for an effective multiobjective process optimisation of machining conditions of multipass lathe operation is developed. The approach integrates the Principal Component Analysis (PCA) and Taguchi methods to optimise the Computerised Numerical Control (CNC) turning process. The targeted Multiple Quality Characteristics (MQCs) are the Dimensional Precision (DP), accuracy and Surface Roughness (SR) of the machined products. Eight control factors such as coolant, cutting speed, feed, depth of cut, coating type, chipbreaker geometry, nose radius and shape of the insert arranged in a L18 orthogonal array are investigated using the Taguchi method. According to the PCA of the experimental results, the verification test of the optimal process conditions shows that the optimal conditions successfully produce the best results on the DP and accuracy and SR. The optimal solution obtained can also be conveniently implemented in the part programmes of a CNC lathe. It is believed that such work can provide a wider acceptance and more practical application of machining economics in industry.

One-Pot Hydrothermal Synthesis of Carbon Dots as Fluorescent Probes for the Determination of Mercuric and Hypochlorite Ions.

Abstract: Nitrogen and sulfur codoped carbon dots (NSCDs) were synthesized via a one-pot hydrothermal method, and citric acid, ethylenediamine, and methyl blue were used as precursors. The obtained NSCDs were spherical with an average size of 1.86 nm. The fluorescence emission spectra of the NSCDs were excitation independent and emitted blue fluorescence at 440 nm with an excitation wavelength at 350 nm. The quantum yield of the NSCDs was calculated to be 68.0%. The NSCDs could be constructed as fluorescent probes for highly selective and sensitive sensing mercuric (Hg2+) and hypochlorite (ClO−) ions. As the addition of Hg2+ or ClO− ions to the NSCDs, the fluorescence intensity was effectively quenched due to dynamic quenching. Under the optimal conditions, the linear response of the fluorescence intensity ranged from 0.7 μM to 15 μM with a detection limit of 0.54 μM and from 0.3 μM to 5.0 μM with a limit of detection of 0.29 μM for Hg2+ and ClO− ions, respectively. Finally, the proposed method was successfully used for quantifying Hg2+ and ClO− ions in spiked tap water samples.

Optically controllable photonic crystals and passively tunable terahertz metamaterials using dye-doped liquid crystal cells

Abstract: This work fabricates a fishnet grating by exerting two one-dimensional (1D) holographic interference fields with mutually orthogonal grating vectors separately on the substrates of a dye-doped liquid crystal (DDLC) cell. The DDLC mixture in the cell includes a nematic LC, methyl red (MR) dye, and 4-methoxyazobenzene (4MAB) dye. The fishnet grating is formed because the periodical adsorption of the MR dye on the irradiated surfaces of the cell causes the anisotropic photoalignment of the LC. The fishnet grating can be erased (recovered) by the illumination of a UV (green) beam since the trans → cis (cis → trans) isomerization of the 4MAB dye causes the isothermal nematic → isotropic (isotropic → nematic) phase transition of the LC. Such a grating can be used to develop optically controllable photonic crystals. Simulated results depict that a photoresist-coated plastic substrate that is exposed to the fishnet pattern of a 2D grating can be used to develop terahertz fishnet metamaterials, and their resonance spectra can be passively tuned by moving the substrate and lens that forms the fishnet pattern during fabrication. Therefore, the mask-free photolithography can be used to fabricate passively tunable terahertz filters.

Differentiated Service Provision in Optical CDMA Network Using Power Control

Abstract: A simple scheme to use power control for differentiated service provision is proposed for the optical code-division multiple-access network. The main advantages of this scheme are: (1) Interference from other users can be eliminated theoretically. (2) The decoder with simple configuration can be used as compared to that in a previous power control scheme. (3) The design procedure of various service requirements in one network is simplified.

Enhanced surface hardness of flexible polycarbonate substrates using plasma-polymerized organosilicon oxynitride films by air plasma jet under atmospheric pressure

Abstract: An investigation is conducted on the enhanced surface hardness of flexible polycarbonate (PC) substrates using high-rate deposition (~ 19.1–19.9 nm/s) of plasma-polymerized organosilicon oxynitride (SiOxCyNz) films with an atmospheric pressure plasma jet (APPJ) at various substrate distances. It is found that the transparent, hard and flexible SiOxCyNz films can be deposited onto PC substrates at room temperature (23 °C) by injection of precursor tetramethyldisiloxan (TMDSO) into air plasma jet at atmospheric pressure. Pencil hardness measurements (ASTM d -3363) demonstrate that the surface hardness of the PC substrate is greatly enhanced from a soft surface of 3B for un-coated PC substrate to a hard surface of 7H for SiOxCyNz film-coated PC substrate. This study indicates that the performance of surface hardness on PC substrates is highly dependent on the surface characteristics of the PC substrates. The surface morphology of the PC substrate is observed by atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM). The atomic compositions and chemical bonds of APPJ-synthesized SiOxCyNz films are analyzed using X-ray photoelectron spectroscopy (XPS) and Fourier transformed infrared spectroscopy (FTIR).