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Ceramic fibers

A Fleming, C Folsom, C Jensen, H Ban
A new fiber-based modulated optical reflectance configuration is developed in this work. The technique maintains the fiber-based heating laser (pump) and detection laser (probe) in close proximity at a fixed separation distance in a ceramic ferrule. The pump beam periodically heats the sample inducing thermal waves into the sample. The probe beam measures the temperature response at a known distance from the pump beam over a range of heating modulation frequencies. The thermal diffusivity of the sample may be calculated from the phase response between the input heat flux and the temperature response of a sample having a reflective surface...
December 2016: Review of Scientific Instruments
Christelle Dubois, Nicole Herzog, Christian Rüttiger, Andreas Geißler, Eléonor Grange, Ulrike Kunz, Hans-Joachim Kleebe, Markus Biesalski, Tobias Meckel, Torsten Gutmann, Markus Gallei, Annette Andrieu-Brunsen
In paper-based devices, capillary fluid flow is based on length-scale selective functional control within a hierarchical porous system. The fluid flow can be tuned by altering the paper preparation process, which controls parameters such as the paper grammage. Interestingly, the fiber morphology and nanoporosity are often neglected. In this work, porous voids are incorporated into paper by the combination of dense or mesoporous ceramic silica coatings with hierarchically porous cotton linter paper. Varying the silica coating leads to significant changes in the fluid flow characteristics, up to the complete water exclusion without any further fiber surface hydrophobization, providing new approaches to control fluid flow...
December 16, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
John L Daristotle, Adam M Behrens, Anthony D Sandler, Peter Kofinas
Solution blow spinning (SBS) is a technique that can be used to deposit fibers in situ at low cost for a variety of applications, which include biomedical materials and flexible electronics. This review is intended to provide an overview of the basic principles and applications of SBS. We first describe a method for creating a spinnable polymer solution and stable polymer solution jet by manipulating parameters such as polymer concentration and gas pressure. This method is based on fundamental insights, theoretical models, and empirical studies...
December 28, 2016: ACS Applied Materials & Interfaces
Verena Wiedemair, Sophia Mayr, Daniel S Wimmer, Eva Maria Köck, Simon Penner, Andreas Kerstan, Patricia-Anca Steinmassl, Herbert Dumfahrt, Christian W Huck
Water absorbed to poly(methyl methacrylate) (PMMA)-based CAD/CAM (computer-assisted design/computer-assisted manufacturing) prosthodontics can alter their properties including hardness and stability. In the present contribution, water absorption and desorption kinetics under defined experimental conditions were monitored employing several supplementary and advanced Fourier transform infrared (FT-IR) spectroscopic techniques in combination with multivariate analysis (MVA). In this synergistic vibrational spectroscopic multimethod approach, first a novel near-infrared (NIR) diffuse fiber optic probe reflection spectroscopic method was established for time-resolved analysis of water uptake within seven days under controlled conditions...
December 12, 2016: Applied Spectroscopy
Ahmad Alobeid, Cornelius Dirk, Susanne Reimann, Tarek El-Bialy, Andreas Jäger, Christoph Bourauel
AIMS: The goal of this study was to determine the mechanical properties of different esthetic and conventional orthodontic wires in three-point and four-point bending tests, and in a biomechanical test employing three bracket systems. METHODS: The behavior of round wires with a diameter of 0.46 mm (0.018″) were investigated: uncoated nickel titanium (NiTi) wires, surface modified NiTi wires; FLI(®) Orthonol Wire(®) and glass fiber reinforced plastic wires. The biomechanical bending test was performed using the following bracket types: metal brackets (Discovery(®), Dentaurum), ceramic brackets (Fascination(®), Dentaurum), and plastic brackets (Elegance(®), Dentaurum)...
December 9, 2016: Journal of Orofacial Orthopedics, Fortschritte der Kieferorthopädie
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
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