다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Fujishima and Honda (1972) demonstrated the potential of titanium dioxide (TiO2) semiconductor materials to split water into hydrogen and oxygen in a photo-electrochemical cell. Their work triggered the development of semiconductor photocatalysis for a wide range of environmental and energy applications. One of the most significant scientific and commercial advances to date has been the development of visible light active (VLA) TiO2 photocatalytic materials. In this review, a background on TiO2 structure, properties and electronic properties in photocatalysis is presented. The development of different strategies to modify TiO2 for the utilization of visible light, including non metal and/or metal doping, dye sensitization and coupling semiconductors are discussed. Emphasis is given to the origin of visible light absorption and the reactive oxygen species generated, deduced by physicochemical and photoelectrochemical methods. Various applications of VLA TiO2, in terms of environmental remediation and in particular water treatment, disinfection and air purification, are illustrated. Comprehensive studies on the photocatalytic degradation of contaminants of emerging concern, including endocrine disrupting compounds, pharmaceuticals, pesticides, cyanotoxins and volatile organic compounds, with VLA TiO2 are discussed and compared to conventional UV-activated TiO2 nanomaterials. Recent advances in bacterial disinfection using VLA TiO2 are also reviewed. Issues concerning test protocols for real visible light activity and photocatalytic efficiencies with different light sources have been highlighted.

/pdf/a-review-on-the-visible-light-active-titanium-dioxide-2qg81s4yao.pdf

A review on the visible light active titanium dioxide photocatalysts for environmental applications

The science and technology of ultracapacitors are reviewed for a number of electrode materials, including carbon, mixed metal oxides, and conducting polymers. More work has been done using microporous carbons than with the other materials and most of the commercially available devices use carbon electrodes and an organic electrolytes. The energy density of these devices is 3¯5 Wh/kg with a power density of 300¯500 W/kg for high efficiency (90¯95%) charge/discharges. Projections of future developments using carbon indicate that energy densities of 10 Wh/kg or higher are likely with power densities of 1¯2 kW/kg. A key problem in the fabrication of these advanced devices is the bonding of the thin electrodes to a current collector such the contact resistance is less than 0.1 cm2. Special attention is given in the paper to comparing the power density characteristics of ultracapacitors and batteries. The comparisons should be made at the same charge/discharge efficiency.

Ultracapacitors: Why, How, and Where is the Technology

This review paper encompasses a detailed study of semiconductor metal oxide (SMO) gas sensors. It provides for a detailed comparison of SMO gas sensors with other gas sensors, especially for ammonia gas sensing. Different parameters which affect the performance (sensitivity, selectivity and stability) of SMO gas sensors are discussed here under. This paper also gives an insight about the dopant or impurity induced variations in the SMO materials used for gas sensing. It is concluded that dopants enhance the properties of SMOs for gas sensing applications by changing their microstructure and morphology, activation energy, electronic structure or band gap of the metal oxides. In some cases, dopants create defects in SMOs by generating oxygen vacancy or by forming solid solutions. These defects enhance the gas sensing properties. Different nanostructures (nanowires, nanotubes, heterojunctions), other than nanopowders have also been studied in this review. At the end, examples of SMOs are given to illustrate the potential use of different SMO materials for gas sensing.

Semiconductor metal oxide gas sensors: A review

In this work, a low-cost and high-resolution x-ray micromask is developed by sputtered lead film on a Mylar sheet substrate with the lift-off process and the x-ray mask is experimented for patterning SU-8 negative photoresist on a glass substrate. Sputtering is selected for Pb thick film deposition due to its high sputtering yield. The Pb mask is used for x-ray lithography of SU-8 photoresist with 5 ?m closely spaced square array patterns, designed for electrowetting electrodes on a microfluidic chip. For 140 ?m thick SU-8 photoresist, a Pb film thickness of around 10 ?m was used to block x-rays with 95% x-ray image contrast at a critical dose of 4200 mJ cm?3. A high aspect ratio of 26.5 of SU8 microstructure with 5 ?m lateral resolution has been demonstrated by the developed low-cost Pb-based x-ray mask. In addition, a steep sidewall angle of nearly 90? for SU-8 structure is confirmed. The results demonstrate that the Pb-based x-ray mask offers high-resolution x-ray lithography at a very low cost. Therefore, it is highly promising for commercial applications.

https://iopscience.iop.org/article/10.1088/0960-1317/20/7/075026/pdf

Low-cost and high-resolution x-ray lithography utilizing a lift-off sputtered lead film mask on a Mylar substrate

In this work, we develop plastic microfluidic chips based on low cost hot embossing process with metal micromold. Metal micromold was formed on aluminum substrates by CNC milling machine and high precision micromachine. The hot embossing system is in-house made with computer aid design by Solid Work program. The system consists of four main parts, structural body, heating system, compressive system and control electronics. The compressive system consists of two top hydraulic single-stage pistons and four middle-stage pistons. Polymethyl methacrylate (PMMA) microfluidic chips were then produced by hot embossing under different applied temperatures and time. It was found that optimum temperature and time for minimum contraction and depth error were 80 degree C and 2–5 minutes. The developed technique offer advantages for microfluidic chip fabrication in term of quality, complexity and cost.

Low cost hot embossing process for plastics microfluidic chips fabrication

This paper discusses the use of solder self-alignment to assemble novel three-dimensional MEMS and package MEMS with other optical devices with precision alignment. Soldering is a predominant technology for electronics assembly, and is being developed for optoelectronic passive alignment. Using solder, hundreds or thousands of precision alignments can be accomplished with a single batch reflow process, and the cost/alignment can be reduced by orders of magnitude.

Solder self-alignment for optical MEMS

Electrochemical Detection of Glutathione Based on Inkjet-Printed Graphene Modified Screen Printed Carbon Paste Electrode

A packaging technology has been developed to integrate a lenslet array with surface micromachined segmented deformablemicromirrors. 12x12 electrostatic micromirror arrays were fabricated through a commercial surface micromachining processand integrated with glass microlenses positioned directly over the micromirror. Control of the spacing and the lateralalignment between the lenslet array and the micromirrors was important for effective fill factor. The spacing control wasaccomplished using a glass spacer, and the lateral alignments were achieved by the use of an interferometric microscope.Measured results of the micromirrors' optical performance demonstrated the success of the packaging technology. 1. INTRODUCTION Micro-electro-mechanical systems (MEMS) offer a novel and cost effective device technology for controlling and compensating the phase of a propagating optical wave front' . With such a control, it is possible to correct aberrations inoptical systems, control the shape of a focused laser beam, and redirect the laser beam. Possible scientific applicationsinclude real time active optical wave front control for correcting atmospheric turbulence effects for astronomy and space

Adisorn Tuantranont

Papers

Low-cost and high-resolution x-ray lithography utilizing a lift-off sputtered lead film mask on a Mylar substrate

Low cost hot embossing process for plastics microfluidic chips fabrication

Solder self-alignment for optical MEMS

Electrochemical Detection of Glutathione Based on Inkjet-Printed Graphene Modified Screen Printed Carbon Paste Electrode

Packaging of lenslet array on micromirrors