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Ceramic fibers

Yuheng Pan, Junfeng Jiang, Kun Liu, Shuang Wang, Tiegen Liu
Response times of fiber Bragg grating (FBG) temperature sensors are investigated. The response model is established and three types of sensors, including bare, gold-coated, and ceramics packaged FBG, are employed to measure their response time under a step simulation. The matched FBG method is used to obtain the response times. Each FBG sensor is measured 5 times and the average values of the sensors are 8.9 ms, 12.3 ms, and 336 ms, respectively. The results are useful for temperature measurement caring about time characteristic...
November 2016: Review of Scientific Instruments
Yixuan Zhang, Chunqing Gao, Qing Wang, Quanxin Na, Meng Zhang, Qing Ye, Mingwei Gao, Jian Zhang
A 2090 nm injection-seeded Q-switched Ho:YAG ceramic laser pumped by a 1.91 μm fiber-coupled LD is demonstrated in this paper. Single-frequency operation of Q-switched Ho:YAG ceramic laser is achieved by injection seeding technique. The maximum output energy of the single-frequency Q-switched Ho:YAG ceramic laser is 14.76 mJ, with a pulse width of 121.6 ns and a repetition rate of 200 Hz. The half-width of the pulse spectrum measured by heterodyne technique is 3.84 MHz. The fluctuation of the center frequency of the pulsed laser is 1...
November 28, 2016: Optics Express
Hao Chen, Ting Zhao, Hao Yang, Le Zhang, Tianyuan Zhou, Dingyuan Tang, Chingping Wong, Yung-Fu Chen, Deyuan Shen
We presented a Ho:LuAG ceramic laser in-band pumped by a narrow emission line-width Tm fiber laser at 1907 nm. All of potential transitions between 5I7 and 5I8 manifold were discussed to form the Ho's in-band-pump energy level systems, which were not described in details earlier. For the emission band centered at ~2095 nm, both laser absorption and emission transition separately consisted of two groups were first analyzed and observed. Using output couplers (OCs) with different transmittances (T = 6, 10 and 20%), the similar ~0...
November 28, 2016: Optics Express
Shupei Zheng, Jiang Li, Chunlei Yu, Qinling Zhou, Danping Chen
This paper presents a novel molten core approach - post-feeding molten core approach - to draw Nd:YAG ceramic derived silica fibers. This technique can effectively mitigate the diffusion of silica from cladding. The diffused silica concentrations decrease from 73.76 wt.% to 45.08 wt.% at the center of cores, by using the post-feeding method. Micro-Raman spectra indicate that the core materials of those fibers are amorphous and maintain an environment similar to YAG glass. The output laser power and slope efficiency are greatly improved...
October 17, 2016: Optics Express
Xinyang Su, Yi Zheng, Junpeng Yang, Qingling Li, Jianwei Li
A "cleaving-polishing" process for end-face treatment of specialty fiber supported by thick-walled silica glass tubes is proposed. The fiber tension is determined by the fiber fracture theory for improved cleaving. This method overcomes polishing problems caused by steel or ceramic ferrules. Approximately 20 min on average is required for polishing a specialty fiber end face with a sampling roughness of 7.42 nm, confirmed by microscopy (400×) and interferometry. A comparison of laser coupling efficiencies between fibers with cleaved ends and fibers with polished ends showed that the coupling efficiency of the former could be enhanced by 15% through polishing...
October 10, 2016: Applied Optics
Ruven Spannagel, Ines Hamann, Josep Sanjuan, Thilo Schuldt, Martin Gohlke, Ulrich Johann, Dennis Weise, Claus Braxmaier
Space applications demand light weight materials with excellent dimensional stability for telescopes, optical benches, optical resonators, etc. Glass-ceramics and composite materials can be tuned to reach very low coefficient of thermal expansion (CTE) at different temperatures. In order to determine such CTEs, very accurate setups are needed. Here we present a dilatometer that is able to measure the CTE of a large variety of materials in the temperature range of 140 K to 250 K. The dilatometer is based on a heterodyne interferometer with nanometer noise levels to measure the expansion of a sample when applying small amplitude controlled temperature signals...
October 2016: Review of Scientific Instruments
Ivana Parčina, Amižić, Anja Baraba
The primary function of an endodontic post is to provide retention for the core and enable full sealing of the coronal portion of the root canal. Traditionally used metal posts do not meet the requirements of modern dental medicine due to some fairly significant drawbacks such as color, corrosion potential, non-adhesive bonding and high modulus of elasticity which can lead to root fracture. Recently, esthetic ceramic and fiber reinforced posts have been manufactured in order to avoid such imperfections. Since much attention has been devoted to the esthetic aspects of dental medicine, the use of these posts with composite/ceramic cores is very common in restorative dentistry and it is actually becoming a standard...
June 2016: Acta Stomatologica Croatica
W Montes-Quiroz, F Baillon, O Louisnard, B Boyer, F Espitalier
A single bubble oscillating in a levitation cell is acoustically monitored by a piezo-ceramics microphone glued on the cell external wall. The correlation of the filtered signal recorded over distant cycles on one hand, and its harmonic content on the other hand, are shown to carry rich information on the bubble stability and existence. For example, the harmonic content of the signal is shown to increase drastically once air is fully dissociated in the bubble, and the resulting pure argon bubble enters into the upper branch of the sonoluminescence regime...
March 2017: Ultrasonics Sonochemistry
Kayla Presley, Jinwoo Hwang, Soshan Cheong, Richard Tilley, Josh Collins, Mariano Viapiano, John Lannutti
Optical oxygen sensors have many promising qualities but rely on excitation by violet or blue wavelengths that suffer from high levels of scattering and absorption in biological tissues. Here we demonstrate an alternative method using 980nm near-infrared light to initially stimulate ceramic upconverting nanoparticles (UCNPs) contained within a novel form, electrospun core-shell fibers. The emission of the UCNPs excites a molecular optical oxygen sensor, the subsequent phosphorescent emission being dynamically quenched by the presence of molecular oxygen...
January 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
Changlei Xia, Andres C Garcia, Sheldon Q Shi, Ying Qiu, Nathaniel Warner, Yingji Wu, Liping Cai, Hussain R Rizvi, Nandika A D'Souza, Xu Nie
Thermal conductivity was dramatically increased after adding natural fiber into hexagonal boron nitride (hBN)/epoxy composites. Although natural fiber does not show high-thermal conductivity itself, this study found that the synergy of natural fiber with hBN could significantly improve thermal conductivity, compared with that solely using hBN. A design of mixtures approach using constant fibers with increasing volume fractions of hBN was examined and compared. The thermal conductivity of the composite containing 43...
October 5, 2016: Scientific Reports
Alessio Cimini, Mauro Moresi
In this work, the crossflow microfiltration performance of rough beer samples was assessed using ceramic hollow-fiber (HF) membrane modules with a nominal pore size ranging from 0.2 to 1.4 μm. Under constant operating conditions (that is, transmembrane pressure difference, TMP = 2.35 bar; feed superficial velocity, vS = 2.5 m/s; temperature, T = 10 °C), quite small steady-state permeation fluxes (J(*) ) of 32 or 37 L/m(2) /h were achieved using the 0.2- or 0.5-μm symmetric membrane modules. Both permeates exhibited turbidity <1 EBC unit, but a significant reduction in density, viscosity, color, extract, and foam half-life with respect to their corresponding retentates...
October 2016: Journal of Food Science
Richard Petersen, Perng-Ru Liu
Three-dimensional (3D)-woven noncrimp fiber-reinforced composite (FRC) was tested for mechanical properties in the two principal directions of the main XY plane and compared to different Computer-Aided-Design/Computer-Aided-Machining (CAD/CAM) Dental Materials. The Dental Materials included ceramic with Vitablock Mark II®, ProCAD®, InCeram® Spinel, InCeram® Alumina and InCeram® Zirconia in addition to a resin-based 3M Corp. Paradigm® particulate-filled composite. Alternate material controls included Coors 300 Alumina Ceramic and a tungsten carbide 22% cobalt cermet...
May 2016: SAMPE Journal
Yue Cao, Ming Wang, Zhen-Liang Xu, Xiao-Hua Ma, Shuang-Mei Xue
A novel seeding method combining interfacial polymerization (IP) technique with dip-coating operation was designed for directly coating nanosized NaA seed crystals (150 nm) onto the micrometer-sized α-Al2O3 hollow fiber support, in which the polyamide (PA) produced by IP acted as an effective medium to freeze and fix seed crystals at the proper position so that the controlled seed layer could be accomplished. While a coating suspension with only 0.5 wt % seed content was used, a very thin seed layer with high quality and good adhesion was achieved through dip coating twice without drying between, and the whole seeding process was operated at ambient conditions...
September 28, 2016: ACS Applied Materials & Interfaces
Yan Chen, Hongwei Liu
Gingival-derived mesenchymal stem cells (GMSCs) have recently been harvested; however, the use of GMSCs in periodontal tissue engineering requires further study. The present study established an indirect co‑culture system between rat apical tooth germ‑conditioned medium (APTG‑CM) and GMSCs, in order to determine the effects on periodontal tissue differentiation in vitro and in vivo. Using the limiting dilution technique, single‑colony derived human GMSCs and periodontal ligament stem cells (PDLSCs) were isolated and expanded to obtain homogeneous populations...
October 2016: Molecular Medicine Reports
Wencai Peng, Zaijin Fang, Zhijun Ma, Jianrong Qiu
Functional nanocrystal-containing materials have been a hot topic in recent years. However, few researches have focused on functional nanocrystals contained in optical glass fibers. In this research, transparent CaF2 glass-ceramic was prepared by a melt-quenching method. Greatly enhanced upconversion luminescence was observed after heat treatment. By applying a novel method called melt-in-tube, precursor fiber free of crystals was fabricated at the drawing temperature where the clad was softened while the core was melted...
October 7, 2016: Nanotechnology
Matthew A Pooley, David M Anderson, Haskell W Beckham, James F Brennan
Composite textile materials, created from a blend of different fibers, have long been used to engineer the properties and performance of fabrics to combine comfort with functionality, such as to create materials with differing optical properties. Some changes to the optical properties of materials in the infrared are subtle and difficult to measure. We present a measurement technique, experimental apparatus, and associated data analysis procedure for detecting small changes in the emissivity of fabrics in the mid-infrared wavelength range (7...
May 16, 2016: Optics Express
R Lan, P Loiko, X Mateos, Y Wang, J Li, Y Pan, S Y Choi, M H Kim, F Rotermund, A Yasukevich, K Yumashev, U Griebner, V Petrov
A Ho:YAG ceramic microchip laser pumped by a Tm fiber laser at 1910 nm is passively Q-switched by single- and multi-layer graphene, single-walled carbon nanotubes (SWCNTs), and Cr<sup>2+</sup>:ZnSe saturable absorbers (SAs). Employing SWCNTs, this laser generated an average power of 810 mW at 2090 nm with a slope efficiency of 68% and continuous wave to Q-switching conversion efficiency of 70%. The shortest pulse duration was 85 ns at a repetition rate of 165 kHz, and the pulse energy reached 4...
June 20, 2016: Applied Optics
Nathan J Kempema, Marshall B Long
Thermographic phosphors (TPs) exhibit a temperature sensitive emission spectrum when excited with ultraviolet radiation. In this study, 14 μm diameter SiC fibers are coated with ZnO or Dy:YAG using a ceramic binder to a total diameter of 70±9 μm. ZnO and Dy:YAG fibers were used to measure fiber temperatures in the range of 294-450 K and 450-1245 K, respectively. The coated fiber provides higher signal levels compared to TP particle seeding and is no more invasive than the commonly used thermocouple. A calibration is performed to relate fiber temperature to the ratio of luminescent signal collected within two different bands of the fiber emission spectrum...
June 10, 2016: Applied Optics
Irem Demirkan, Ayse Sena Kabas Sarp, Murat Gülsoy
No abstract text is available yet for this article.
June 1, 2016: Journal of Biomedical Optics
C Atalay, A R Yazici, A Horuztepe, E Nagas, A Ertan, G Ozgunaltay
: The aim of this in vitro study was to evaluate the fracture resistance of endodontically treated teeth restored with different types of restorative resins. METHODS AND MATERIALS: Seventy-two sound maxillary premolar teeth were randomly divided into six groups (n=12). The teeth in the first group were left intact and tested as unprepared negative control (group I) specimens. The teeth in the remaining five groups were prepared with MOD cavities and endodontically treated...
June 28, 2016: Operative Dentistry
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