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The work aims to study the evaporation process of borosilicate glass used for strengthening of silica fiber light guides. The composition of glass after high-temperature treatment was determined based on refractive index measurement. It was found that at temperature 2100 °C two-component SiO2-B2O3 glass vaporizes without changing its composition at a boron oxide content of ≈ 4 mol% in both oxygen and nitrogen atmospheres. The IR absorption spectra of borosilicate glass indicate the absence of boroxol rings of B2O3, which can explain the low partial pressure of its vapors compared to the ideal melt state. It is experimentally shown that the content of only 1 mol % B2O3 in the outer cladding of silica fiber increases its strength by 10% when the drawing temperature is reduced to 1900 °C. Such a small addition of boron oxide to silica glass decreases its viscosity, ensuring the occurrence of compressive stresses in the borosilicate cladding. [ABSTRACT FROM AUTHOR]

• The rapid development of electronic sensors triggered the research of optical tactile sensor. • We review the recent progress in the field of optical tactile sensor, focusing on the latest research results. • We guide the reader to review paper and compare those different types of optical tactile sensors. Over the past decade, flexible electronics has become a cutting-edge technology owing to its broad applications in robotics, health monitoring, and human-machine interface. The recent development of flexible electrical tactile sensor triggers the research of optical tactile sensors due to their potentials in high-sensitivity, high-precision, low power consumption, and anti-electromagnetic interference. Here, this review mainly discusses the advances and applications of silica fiber, polymer fiber, hydrogel, and micro/nanofiber based tactile sensors, specifically, focusing on the latest research results and on the necessary technologies to enable the health monitoring, robotics, and human-machine interface applications. Furthermore, future outlooks in developing skin-like optical tactile sensors are also presented. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Electrospinning porous silica fiber ( Epsf) prepared by electrospinning as the catalyst carrier, took Co and Zn as bimetallic active components. The bimetallic load-type catalyst was prepared by the equal volume impregnation method, and the technical features of SEM, XRF were used to explore the effect of its application on the degradation effect of chemical wastewater. The results showed that when the mass ratio of the Zn and Co bimetal components in the catalyst was 1 1, its synergistic ozone had a good treatment effect on wastewater. The COD degradation rate of wastewater was 97. 1% within 100 min,and after the catalyst was reused 7 times,the COD degradation rate of wastewater could still reach 79. 1%. [ABSTRACT FROM AUTHOR]

Silica nanofibers were prepared by electrospinning technique, and then a sodium alginate coated three-dimensional silica hemostatic sponge (ALG/SiO2/Ca2+ sponge) was obtained by freeze-drying method and Ca2+ crosslinking. The structure, composition, cytotoxicity, biocompatibility and hemostatic function were characterized by scanning electron microscopy, cell experiments and in vivo hemostasis experiment. The results show that the ALG/SiO2/Ca2+ hemostatic sponge has a highly porous structure and fast swelling performance. Immersed in water for 10s, the volume expands to 219% compared with the original. The results of cell experiments show that the new hemostatic sponge has good cytocompatibility; the results of in vivo hemostasis show that hemostasis is achieved within 10s using the ALG/SiO2/Ca2+ hemostatic sponge, and the amount of bleeding is significantly reduced compared with medical gauze. Therefore, this new type of hemostatic sponge has excellent properties such as rapid water swelling and hemostasis in the deep wound and providing a moist environment for wound.

In the feasibility studies used for the correct use of this side product, it was decided to investigate the effect of this substance in a light concrete. Due to the low specific gravity, the lightweight concrete is less resistant compared to other concretes. So, in this study, the effect of nanocrystalline silica nano and micro and macro silica fibers, a mineral extracted on the mechanical properties of light concrete, including the compressive strength and tensile strength, were investigated. The results showed the improvement of the mechanical properties of the light concrete for the use of nano silica to 4% cement weight. By combining nanosilica with micro silica and its effect on the mechanical properties of concrete, we found that the highest compressive strength was in using 2% nano silica and 8% micro silica. However, the combination of the nano-silica with a percentage of more than 8% of micro silica reduced the mechanical properties of the sample. Also, the mixing of macro-silica in concrete up to 25% increased the tensile and compressive strength.

Fluoxetine is used as an effective antidepressant in psychopharmacology. As a pharmaceutical and personal care product (PPCP) found in superficial waters, fluoxetine influences the wildlife that inhabit these waters. This study was conducted to determine the fluoxetine concentration even in trace quantity in the hospital wastewater, using a solid-phase microextraction (SPME) silica fiber layered with single-walled carbon nanotubes (SWCNTs). An instrumental setup including off-line SPME, which uses a simple carbon nanotube (CNT) to bond capillary column combined with fluorescence spectrometry, was arranged as a sensitive method for the quantification of fluoxetine in real sample. A one at-a-time optimization strategy was applied for optimizing extraction parameters such as extraction time, stirring rate, desorption time, pH, and salt effect on the extraction, preconcentration and determination of fluoxetine in aqueous samples. The advantages of the developed method were: being simple to use with shorter amounts of time for analysis, lower equipment costs, thermal stability of fiber, and high relative recovery in contrast to conventional methods of analysis. Linear ranges were within 0.1-30 µg/L and the detection limit for the fluoxetine was 1×10-4 µg/L.

Temperature monitoring is extremely important during thermotherapy. Fiber‐optic temperature sensors are preferred because of their flexibility and immunity to electromagnetic interference. Although many types of fiber‐optic sensors have been developed, clinically adopting them remains challenging. Here, we report a silica fiber‐based radiometric thermometer using a low‐cost extended InGaAs detector to detect black body radiation between 1.7 and 2.4 μm. For the first time, this silica fiber‐based thermometer is capable of measuring temperatures down to 35°C, making it suitable for monitoring hyperthermia during surgery. In particular, the thermometer has potential for seamless integration with current silica fiber catheters, which are widely used in laser interstitial thermotherapy. The feasibility, capability and sensitivity of tracking tissue temperature variation were proved through ex vivo tissue studies. After further improvement, the technology has the potential to be translated into clinics for monitoring tissue temperature. [ABSTRACT FROM AUTHOR]

In order to improve the chemical leachability, the alumina-based ceramic core material with the silica fiber was injected and sintered at 1100 °C/4 h, 1200 °C/4 h, 1300 °C/4 h and 1400 °C/4 h, respectively. The micrographs of ceramic core materials at sintered and leached state were characterized by scanning electron microscopy (SEM). The phase composition of ceramic core material after sintering and the leaching product after leaching were detected by X-ray diffraction (XRD). The porosity, room temperature bend strength, creep property at elevated temperature and the leaching rate in aqueous caustic solution were studied. The experimental results show that the ceramic core material with silica fiber obtain a fair balance between mechanical and chemical properties at sintering of 1300 °C/4 h. Specifically, the leach rate of ceramic core material with silica fiber is increased apparently. High leaching surface and weak adhesive strength between agglomerated alumina particles are the reasons that responsible for the ceramic core material with silica fiber be leaching fast than that of the ceramic core material without fiber.

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract The study of the protection performance provided by fibrous fireproofing materials asks for simple and reliable models for the description of their thermal behavior in accident scenarios involving industrial fires. This paper focuses on the development and validation of a physical model for effective thermal conductivity in highly porous fibrous materials used in industrial fireproofing applications. Unlike other literature models, that include several adjustable parameters, the proposed model mainly relies on physical and easily measurable properties of the material (void fraction, average fiber diameter, bulk conductivity of the phases, etc.). The model was validated against experimental data measured for three commercial passive fire protection materials. If compared with the models currently available in the literature, the proposed model shows a better correlation to the experimental data, especially at higher temperature, where radiation is the predominant phenomenon. Highlights • A model for effective thermal conductivity of inorganic PFP materials was developed. • The model was validated for three commercial fireproofing materials. • A better correlation to data than comparable models was shown. • The model is applicable to finite volume simulation of the fireproofing performance. [ABSTRACT FROM AUTHOR]

A solution‐phase synthesis of silica fibers is demonstrated. Silica fibers with length up to 50 μm and diameter ≈ 300 nm were synthesized. Fiber structure was characterized by using scanning electron microscope (SEM), transmission electron microscope (TEM), Brunauer‐Emmett‐Teller (BET) surface area analysis, and Barrett‐Joyner‐Halenda (BJH) pore size and volume analysis. Fiber reinforced polymer composite films were made and investigated to demonstrate the use of these fibers as a reinforce material. A polymer composite film having 6% of silica fibers showed 38% and 16% increase in the Young's modulus and the yield point, respectively, when compared to the Young's modulus and yield point of the polymer alone. Composite films had quite good visible transmittance (>90%). A new solution‐phase synthesis strategy with a potential to provide large quantity of long silica fibers is presented. The fibers were almost solid and did not contain much porosity. The fibers were also employed to make transparent and high‐strength fiber‐polymer composite films. [ABSTRACT FROM AUTHOR]

In this paper, the thermo-optic coefficient of silica fiber is analyzed and measured within a wide temperature range of 0–1200 °C for the first time. To obtain the thermo-optic coefficient, experiments were carried out by using fiber optic extrinsic Fabry–Perot interferometers (EFPIs) embedded in silica fiber. The optical cavity lengths of the EFPIs were measured with white-light interferometry. The experimental results show that the first and second orders of the thermo-optic coefficient are 1.090 × 10−5/°C and 1.611 × 10−9/°C2, respectively. The quadratic model for the temperature dependence of the basic optical parameter, the refractive index, is rigorous within a wide temperature range. Furthermore, this paper also provides a temperature calibration method for extrinsic Fabry–Perot interferometric temperature sensors. The temperatures measured by the sensors are in excellent agreement with those measured by the reference thermocouple. Hence, this calibration method is promising for temperature sensors with a wide working temperature range. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • We provide passivation calculation with H/F in silica fiber. • H/F form robust Si H/Si F bond which can improve electro optic properties. • F is the better passivator combined with electro optic properties. Abstract We present first-principles combined GW and Bethe-Salpeter equation on passivation effect between ODC(I) and H/F atoms. The injection of H or F atoms help to form the robust Si H or Si F bond which increase the optical band gap, erase the defect state of ODC(I) at 0.74 eV and improve radiation toughness. The reaction of ODC(I) defect with a H atom or F atoms is barrierless, the Si O length near the ODC(I) sites are all gradually getting shorter and bond energy are getting stronger. Coupled with the atomic structures and electro-optic properties, we found out that F is the better passivator. [ABSTRACT FROM AUTHOR]

We present first principles calculations on conversion of a peroxy linkage (POL, Si   O   O   Si ) defect. GW and Bethe-Salpeter equation methods are introduced. POL defect has different reaction paths when interacts with H 2 . It will convert into silanol (Si OH+Si OH) at the ground state (S 0 ) and likely to transfer into Si OOH + Si H at the triplet state (T 1 ). Optical absorption strength of hydrogen-induced defects is higher than the POL defect between 6 and 8 eV and would be more easily lead to a laser-induced damage phenomenon. Our results not only display a better understanding of how H 2 molecular interacts with the POL defect, but also provide a guidance to figure out these defects in silica fiber. [ABSTRACT FROM AUTHOR]

Ni/SiO2 (Ni/SF) catalysts were prepared by electrospinning of the SF followed by impregnation. The performance of the Ni/SF catalysts for hydrogen production from ethanol steam reforming at various conditions was investigated in comparison with a conventional Ni/silica porous (Ni/SP) catalyst. The influence of the Ni/SF catalyst preparation methods on the catalytic activity and stability in ethanol steam reforming was also studied. The catalysts were prepared by three different preparation techniques: impregnation (IM), deposition precipitation (DP) and strong electrostatic adsorption (SEA). The Ni/SF catalyst exhibited higher performances and stability than the Ni/SP catalyst. The H2 yields of 55% and 47% were achieved at 600 °C using the Ni/SF and Ni/SP catalysts, respectively. The preparation methods had a significant effect on the catalytic activity and stability of the Ni/SF catalyst, where that prepared by the SEA method had a smaller Ni particle size and higher dispersion, and also exhibited the highest catalytic activity and stability compared to the Ni/SF catalysts prepared by IM and DP methods. The maximum H2 yield produced from the catalyst prepared by SEA was 65%, while that from the catalysts prepared by DP and IM were 60% and 55%, respectively, under the same conditions. The activity of the fiber catalysts prepared by SEA, DP and IM remained almost constant at all times during a 16 h stability test. [ABSTRACT FROM AUTHOR]

We studied the influence of silica and glass fibers on the properties of polyester non-woven padding, fixing interesting changes in thermoinsulation, thickness and stiffness of obtained composites. It was found that the combination of inorganic and polyester fibers allowed for obtaining improved thermoinsulating property, compared to non-woven materials based on individual fibers. The improvement is attributed to the enhanced reflectance and the decreased air permeability, which can reduce the heat lost through radiation and convection. The application of inorganic fibers also made the development of non-woven materials with small thickness, keeping thermoinsulating property similar or better, compared to the commonly used polyester non-woven padding. Furthermore, the designed non-woven composites in real models of winter jackets were evaluated in a climate chamber at -10 °C by infrared thermal camera. The results showed that the addition of inorganic fibers allowed the surface temperature of winter jackets more than 5 °C lower than that of winter jacket with pure polyester padding. They significantly enhanced the protection from cold and reduced heat loss from the human body. [ABSTRACT FROM AUTHOR]

A novel fibrous composite of platelet carbon nanofibers-silica fiber (PCNFs-SF) was synthesized via acetic acid steam reforming (ASR) and then employed as a support for a Co catalyst in the ASR. For comparison, the catalytic behavior of cobalt (Co) catalysts supported on carbon nanotubes-silica fiber (CNTs-SF), silica fiber (SF) and porous silica (Q10) was also studied. The characterization by field emission scanning electron microscopy and transmission electron microscopy analyses demonstrated that the PCNFs-SF was like graphite stacked platelets. Both PCNFs-SF and CNTs-SF composite supports enhanced the dispersion of metallic cobalt to achieve smaller Co 2 O 3 particle sizes and strengthen the metal-support interaction. Consequently, the Co/PCNFs-SF and Co/CNTs-SF composite catalysts afforded a higher ASR catalytic activity and selectivity towards hydrogen production than that of the Co/SF and Co/Q10 catalysts. The presence of the carbon nanostructure in the catalyst composites was also found to improve the long-term stability in ASR. The activity of the Co/PCNFs-SF and Co/CNTs-SF composite catalysts remained stable all times during a 12 h stability test. The strong interaction between metal and support together with the unique structure of PCNFs-SF and CNTs-SF composites could effectively suppress deactivation of the catalysts in ASR. [ABSTRACT FROM AUTHOR]

The development of green sustainable chemistry opens the door to the application of biocatalytic in numerous fields for the research in industry and academia. As a common biological catalyst, enzyme catalysis is ideally suited and widely applicable for various desired reaction. In this work, a hierarchical structure laccase-Cu3(PO4)2·3H2O nanoflower-coated silica fiber (La-CNSF) was successfully fabricated with hundreds of Cu3(PO4)2 nanosheets formed on the processed silica fibers as the petal and laccase as the enzyme catalyst. It included two processes: first, Cu nanoparticles were directly grown on silica fiber cloth as a precursor and three-dimensional (3D) Cu3(PO4)2·3H2O nanoflower was self-assembled on Cu-coated fibers by post-processing. Then, La-CNSF was successfully immobilized via a simple one-step immersion reaction in a laccase-phosphate buffer solution (PBS) solution. The product was characterized by FTIR, XRD, SEM and UV-visible spectroscopy. Congo red was realized using La-CNSF as a biocatalyst. Compared with pure laccase, La-CNSF sample exhibits an enhanced catalytic activity. The flower-like structure assembled on the fiber provided La-CNSF high storage stability and reusability in contrast with free laccase. The superior catalytic performance of La-CNSF supports a potential strategy for purification of water pollutants, and it favors the realization of the engineering of large scale applications of enzyme catalysis. [ABSTRACT FROM AUTHOR]

We report the design, experimental performance, and simulation of a single stage, co- and counter-pumped Tm-doped fiber amplifier (TDFA) in the 2 μm signal wavelength band with an optimized 1567 nm shared pump source. We investigate the dependence of output power, gain, and efficiency on pump coupling ratio and signal wavelength. Small signal gains of >50 dB, an output power of 2 W, and small signal noise figures of <3.5 dB are demonstrated. Simulations of TDFA performance agree well with the experimental data. We also discuss performance tradeoffs with respect to amplifier topology for this simple and efficient TDFA. [ABSTRACT FROM AUTHOR]

In-situ monitoring of the multi-component gas streams in high temperature energy conversion devices offer the promises to higher efficiency via improved understanding of the chemical environments during device operation. While conventional resistive based metal oxide semiconductor gas sensors suffer from strong cross-sensitivity, optical sensing approaches offer intrinsic advantages to achieve gas selectivity based on wavelength specific interactions. This manuscript describes a novel method to achieve multicomponent gas sensing during gas exposure of H 2 , CO 2 , CH 4 and CO in humid high temperature environments. A single sensor element comprised of a perovskite La 0.3 Sr 0.7 TiO 3 (LSTO) oxide thin film layer coated on silica optical fiber was used. The sensing responses consisted of two wavelength-specific near infrared (NIR) mechanisms, namely broadband absorption associated with the metal oxide layer, and wavelength localized thermal emission responses associated with the hydroxyl defects within the silica fiber. Principal component analysis (PCA) was applied to couple the two mechanisms to achieve selective gas identification. Successful discrimination of H 2 and CO 2 on a single fiber sensor was achieved, where the results are both stable and reversible. This design demonstrates that by coupling multiple optical mechanisms on a single oxide coated fiber sensor, simple platforms can also achieve multi-component sensing functionality without the added complexity of a sensor array. Thus, it suggests a new approach to construct simple, robust and functional sensor designs capable of gas discrimination and quantification in multi-component gas streams. [ABSTRACT FROM AUTHOR]

In order to improve the chemical leachability, the alumina-based ceramic core material with the silica fiber was injected and sintered at 1100 °C/4 h, 1200 °C/4 h, 1300 °C/4 h and 1400 °C/4 h, respectively. The micrographs of ceramic core materials at sintered and leached state were characterized by scanning electron microscopy (SEM). The phase composition of ceramic core material after sintering and the leaching product after leaching were detected by X-ray diffraction (XRD). The porosity, room temperature bend strength, creep property at elevated temperature and the leaching rate in aqueous caustic solution were studied. The experimental results show that the ceramic core material with silica fiber obtain a fair balance between mechanical and chemical properties at sintering of 1300 °C/4 h. Specifically, the leach rate of ceramic core material with silica fiber is increased apparently. High leaching surface and weak adhesive strength between agglomerated alumina particles are the reasons that responsible for the ceramic core material with silica fiber be leaching fast than that of the ceramic core material without fiber. [ABSTRACT FROM AUTHOR]