Refrigerative Stereolithography Using Sol-Gel Transformable Photopolymer Resin and Direct Masking

2000 ◽  
Vol 625 ◽  
Author(s):  
T. Murakami ◽  
A. Kamimura ◽  
N. Nakajima
Keyword(s):  
Liquid Layer ◽  
Light Exposure ◽  
Sol Gel ◽  
Experimental Results ◽  
Fabrication Method ◽  
Resin Layer ◽  
Direct Light ◽  
Section Shape

AbstractThe authors have been studying a new fabrication method termed “refrigerative stereolithography” which uses a gel resin layer instead of a liquid layer as in conventional stereolithography. This paper proposes the “direct masking method” in which a masking pattern is drawn to block direct light exposure to the surface of the gel resin layer. With such masks, we can avoid surplus growth only in the regions where it is unnecessary to improve height direction accuracy and resolution. Also, we can solidify the required section shape selectively using the masks and a lamp instead of laser scan patterns. The effectiveness of refrigerative stereolithography with the direct masking method is discussed and confirmed by some experimental results.

Refrigerative Stereolithography Using Sol-Gel Transformable Photopolymer Resin and Direct Masking

2000 ◽  
Author(s):  
Tamotsu Murakami ◽  
Akiya Kamimura ◽  
Naomasa Nakajima
Keyword(s):  
Liquid Layer ◽  
Light Exposure ◽  
Sol Gel ◽  
Light Reflection ◽  
Layer Surface ◽  
Fabrication Method ◽  
Gel Layer ◽  
Section Shape ◽  
Width Direction ◽  
Simulation And Experiment

Abstract The authors have been studying a new fabrication method termed “refrigerative stereolithography” which uses a gel resin layer instead of a liquid layer used in conventional stereolithography. In this paper, we propose the “direct masking method” in which a masking pattern is drawn directly on a gel layer surface to block harmful light exposure of photopolymer resin. With such masks, we can avoid surplus growth only in the regions where it is unnecessary to improve height direction accuracy and resolution. The possibility of surplus growth in the width direction caused by light reflection from the mask surface is pointed out, and the effect is analyzed and confirmed by simulation and experiment. This new surplus growth is termed “reflective surplus growth”. Also, we can solidify the required section shape selectively using the masks and a lamp instead of laser scan patterns. The effectiveness of refrigerative stereolithography with the direct masking method is discussed and confirmed by some experimental results.

scholarly journals The Influence of Calcination Temperature on Photocatalytic Activity of TiO2-Acetylacetone Charge Transfer Complex towards Degradation of NOx under Visible Light

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1463
Author(s):  
Lucas A. Almeida ◽  
Margarita Habran ◽  
Rafael dos Santos Carvalho ◽  
Marcelo E. H. Maia da Costa ◽  
Marco Cremona ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Charge Transfer ◽  
Visible Light ◽  
Calcination Temperature ◽  
Charge Transfer Complex ◽  
Light Exposure ◽  
Sol Gel ◽  
Solar Spectrum ◽  
Photocatalytic Efficiency ◽  
Nanocrystalline Tio2

The improvement of photocatalytic activity of TiO2-based nanomaterials is widely investigated due to the tentative of their industrialization as environmental photocatalysts and their inherently low solar spectrum sensitivity and rapid recombination of charge carriers. Coupling of oxygen-based bidentate diketone to nanocrystalline TiO2 represents a potential alternative for improving the holdbacks. Formation of TiO2-acetylacetone charge transfer complex (CTC) by sol-gel route results in a hybrid semiconductor material with photodegradation activity against toxic NOx gas. In this research, the influence of the chelating agent acetylacetone (ACAC) content on the CTC photocatalytic efficiency under visible light was evaluated. A high content of ACAC in the CTC is not a decisive factor for efficiency of photocatalytic reactions. In fact, the highest efficiency for NOx degradation (close to 100%, during 1 h of visible light exposure) was reported for the material calcined in air at 300 °C with the content of strongly bonded acetylacetone not higher than 3 wt.%. Higher calcination temperature (400 °C) left TiO2 almost completely depleted in ACAC, while at the highest applied temperature (550 °C) a portion of anatase was transformed into rutile and the sample is free of ACAC. The analyses pointed out that superoxide anion radical (O2−) plays an active role in photo-oxidation of NOx. Our findings indicate that this CTC has both high visible light spectral sensitivity and photocatalytic efficiency.

Application of Nanometer Metal Oxides in Infrared Ray Shielding Transparent Thin Film

2011 ◽  
Vol 474-476 ◽  
pp. 195-199 ◽  
Author(s):  
Ai Hong Guo ◽  
Xue Jiao Tang ◽  
Su Juan Zhang
Keyword(s):  
Thin Film ◽  
Metal Oxide ◽  
Metal Oxides ◽  
Sol Gel ◽  
Volume Ratio ◽  
Experimental Results ◽  
Mass Ratio ◽  
Gel Method ◽  
Water Based ◽  
Better Than

Water-based infrared ray shielding coating, that is, nanometer metal oxide is added to the water-based paint, which has anti-IR features without affecting the transparency of the paint. In this paper, the nanometer oxides are prepared by sol-gel method, added into polypropylene sour. In order to improve the infrared ray shielding of the thin film, two kinds of nanometer oxides are added into the polypropylene sour with different volume ratios, the shielding performance of the paint is studied. Experimental results show: in the 8000 ~ 4000cm-1 range, the transmittances of infrared ray is 30% to 75%; in 4000 ~ 400cm-1 range, transmittances decrease significantly; 3% ZnO, 3% Fe2O3, 3% Y2O3, 2% Al2O3 are the best mass ratio of every single nanometer oxide; the infrared shielding rate of Fe2O3 and Y2O3 mixture with the volume ratio of 1 to 4 is better than Fe2O3 and Y2O3 single.

Fabrication of Bi-2223 Powders Using Sol-Gel Method

2011 ◽  
Vol 412 ◽  
pp. 125-128 ◽  
Author(s):  
Ming Ya Li ◽  
Xiao Yan Wang ◽  
Cheng Li Ye ◽  
Feng Lin Xue
Keyword(s):  
Heat Treatment ◽  
Sol Gel ◽  
Chelating Agent ◽  
Experimental Results ◽  
Main Phase ◽  
Gel Method ◽  
Sol Gel Method ◽  
Dwelling Time ◽  
Metal Nitrates ◽  
Gel Technique

The Bi-2223 powders were fabricated by the sol-gel technique. Metal nitrates were used as starting materials, and ethylenediamineteracetic acid was used as chelating agent. The solution was heated until it turns to gel. Then the organic was removed at a temperature of 240°C, and the nitrite was removed at 500°C. The powder was calcined at different temperature, varying the dwelling time. Experimental results show that the main phase of samples after heat treatment is Bi-2212 phase.

scholarly journals Indirect Restoration Thickness and Time after Light-Activation Effects on Degree of Conversion of Resin Cement

2015 ◽  
Vol 26 (4) ◽  
pp. 363-367 ◽  
Author(s):  
Ana Paula Almeida Ayres ◽  
Carolina Bosso Andre ◽  
Rafael Rocha Pacheco ◽  
Adriana Oliveira Carvalho ◽  
Renata Cantanhede Bacelar-Sá ◽  
...  
Keyword(s):  
Light Exposure ◽  
Degree Of Conversion ◽  
Resin Cement ◽  
The Self ◽  
Diamond Surface ◽  
Light Activation ◽  
Curing Conditions ◽  
Direct Light ◽  
Restorative Materials ◽  
Post Hoc

<p>This study evaluated the effects of indirect restorative materials, curing conditions and time on the degree of conversion (DC) of a dual-cured resin cement using infrared spectroscopy. The resin cement (RelyX Unicem 2, 3M ESPE) was applied to the diamond surface of a horizontal attenuated-total-reflectance unit and activated using one of following conditions: self-cure, direct light exposure, light exposure through indirect restorative materials (resin nano-ceramic: Lava Ultimate, 3M ESPE or feldspathic ceramic: Vita Blocks Mark II, Vita Zahnfabrik). Four thicknesses (0.5, 1.0, 1.5 or 2.0 mm) of each indirect material were analyzed, and the light-activation was performed using a blue LED light. Data (n=5) were analyzed by three-way ANOVA, Tukey's post hoc and Dunnett's tests (α=5%). No significant differences in DC were observed between indirect materials of similar thickness. All groups exhibited higher DC after 10 min than after 5 min. At both times points, the self-cure group exhibited significantly lower DC than all the light exposure groups. Only when the overlying indirect restoration had a thickness of 2 mm did DC decrease significantly. The presence of a thick, indirect restoration can decrease the DC of resin cement. DC after 10 min was higher than after 5 min. The self-cure mode yielded lower DC than the light-activating one.</p>

Bessel beam ultrasonic transducer: Fabrication method and experimental results

1989 ◽  
Vol 55 (20) ◽  
pp. 2066-2068 ◽  
Author(s):  
D. K. Hsu ◽  
F. J. Margetan ◽  
D. O. Thompson
Keyword(s):  
Ultrasonic Transducer ◽  
Bessel Beam ◽  
Experimental Results ◽  
Fabrication Method

Effect of Ag and Au doping on the photocatalytic activity of TiO2 supported on textile fibres

2008 ◽  
Vol 1077 ◽  
Author(s):  
Mohammed Jasim Uddin ◽  
Federico Cesano ◽  
Domenica Scarano ◽  
Silvia Bordiga ◽  
Adriano Zecchina
Keyword(s):  
Thin Films ◽  
Light Exposure ◽  
Sol Gel ◽  
Tio2 Thin Films ◽  
Simple Method ◽  
Purple Colour ◽  
Cotton Fibres ◽  
Vis Spectroscopy ◽  
Cotton Textiles ◽  
Grey Colour

ABSTRACTA simple method to develop TiO2, Ag or Au-doped TiO2 thin films on cotton textiles for advanced applications, is reported. The homogeneous TiO2 thin films have been deposited on cotton textiles by using sol-gel method at low temperature (100° C), whereas Ag and Au nanoparticles were then deposited on the pre-existent TiO2 films by photoreduction. The Ag/TiO2 covered cotton fibres show multichromic behaviour (grey colour under visible light and brown colour upon ultraviolet light exposure) as well as photoactivity. The Au-TiO2 film coated the cotton textile produces a purple colour with excellent self cleaning properties. The original and treated fibres have been characterized by several techniques (SEM, HRTEM, FTIR, Raman, UV–vis spectroscopy and XRD).

Nonstoichiometry and Point Defect Structure of Olivines, (FexMg1-x)2SiO4

1994 ◽  
Vol 369 ◽  
Author(s):  
Tse-Lun Tsai ◽  
R. Dieckmann
Keyword(s):  
Transition Metal ◽  
Point Defect ◽  
Noble Metal ◽  
Defect Structure ◽  
Elevated Temperatures ◽  
Sol Gel ◽  
Experimental Results ◽  
Cationic Composition ◽  
Gel Method ◽  
Point Defect Structure

AbstractA thermogravimetric study was conducted on synthetic olivines (FexMg1-x)2SiO4' prepared either by a conventional ceramic methodor a sol-gel method, to determine the nonstoichiometry and the point defect structure. Measurements were carried out as a function of oxygen activity and cationic composition at elevated temperatures. To avoid the dissolution of transition metal components of the silicate into noble metal containers, commonly used in previous investigations, quartz containers were used. The analysis of the point defect structure of olivines based on the new experimental results is presented.

STUDIES ON THE TiO2 THIN FILMS DOPED WITH Fe3+

2005 ◽  
Vol 19 (01n03) ◽  
pp. 671-673
Author(s):  
PENG XIAO ◽  
WANLU WANG
Keyword(s):  
Thin Films ◽  
Raman Spectroscopy ◽  
Electrical Properties ◽  
Sol Gel ◽  
Experimental Results ◽  
X Ray Diffraction ◽  
Tio2 Thin Films ◽  
Gel Method ◽  
X Ray ◽  
Nanometer Particles

The Fe 3+- TiO 2 thin films obtained through sol-gel method were characterized by x-ray diffraction, AFM and Raman spectroscopy. It was found that TiO 2 films consisted of nanometer particles. The experimental results shows that the nanometer TiO 2 thin films doped with Fe 3+ were greatly improved in the activity aspect. This may be ascribed to change their structure and electrical properties after doping with Fe 3+. The results were discussed theoretically in detail.

scholarly journals Density and habitat characterization of Aedes sp. breeding places in dengue Endemic Area in Bandar Lampung

2021 ◽  
Vol 886 (1) ◽  
pp. 012065
Author(s):  
S Nurjanah ◽  
T Atmowidi ◽  
U K Hadi ◽  
D D Solihin ◽  
W Priawandiputra
Keyword(s):  
Endemic Area ◽  
Light Exposure ◽  
Cross Sectional Study ◽  
Habitat Characteristics ◽  
Water Volume ◽  
Haemorrhagic Fever ◽  
Sectional Study ◽  
Cross Sectional ◽  
Direct Light

Abstract Aedes sp. are vectors of the dengue virus that causes Dengue Haemorrhagic Fever (DHF). The purposed of this study to analyze habitat characteristics of Aedes sp. based on the entomological index and measure the density and species of larvae Aedes sp. The research was analytic observational with a cross-sectional study was conducted 3 subdistricts of endemic in Bandar Lampung. The results showed that from 3 locations, namely Sukarame, Kemiling and Tanjung Seneng, the House Index (HI) values were 41, 38, 31, respectively. The Container Index (CI) values were 14, 12, 10 respectively and the Breteau index (BI) values were 105, 77, 60 respectively. The result of density figure (DF) were 5-6 which means the density of Aedes sp. were moderate to high. The result of identification of larvae were 3 species of mosquito were Aedes aegypti, Aedes albopictus and Culex quinquefasciatus. The dominant spesies of larvae were found are Ae. aegypti. The characteristics of larvae habitat as a risk factor for increasing the density of mosquito in Bandar Lampung are buckets or container made of plastic or cement and dispenser, light colour, direct light exposure, 1-20 liters water volume, no cover container, no drainage, and no fish rearing.

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