WorldWideScience

Sample records for hollow fiber renewal

  1. Removal of Aniline from Wastewater Using Hollow Fiber Renewal Liquid Membrane☆

    Institute of Scientific and Technical Information of China (English)

    Zhongqi Ren; Xinyan Zhu; Wei Liu; Wei Sun; Weidong Zhang; Junteng Liu

    2014-01-01

    Hol ow fiber renewal liquid membrane (HFRLM) method was proposed based on the surface renewal theory for re-moval of aniline from waste water. The system of aniline+D2EHPA in kerosene+HCl was used. Aqueous layer diffusion in the feed phase is the rate-control step, and the influence of lumen side flow rate on the mass transfer is more significant than that on the shel side. The resistance of overal mass transfer is greatly reduced because of the mass transfer intensification in the renewal of liquid membrane on the lumen side. The driving force of mass transfer can be considered as a function of distribution equilibrium, and the overall mass transfer coefficient in-creases with the increase of pH in the feed solution, HCl concentration and D2EHPA concentration, and decreases with the increase of initial aniline concentration. A mass transfer model is developed for HFRLM based on the surface renewal theory. The calculated results agree wel with experimental results. The HFRLM process is a promising method for aniline wastewater treatment.

  2. Hollow-Fiber Clinostat

    Science.gov (United States)

    Rhodes, Percy H.; Miller, Teresa Y.; Snyder, Robert S.

    1990-01-01

    Hollow-fiber clinostat, is bioreactor used to study growth and other behavior of cells in simulated microgravity. Cells under study contained in porous hollow fiber immersed in culture medium inside vessel. Bores in hollow fiber allow exchange of gases, nutrients, and metabolic waste products between living cells and external culture media. Hollow fiber lies on axis of vessel, rotated by motor equipped with torque and speed controls. Desired temperature maintained by operating clinostat in standard tissue-culture incubator. Axis of rotation made horizontal or vertical. Designed for use with conventional methods of sterilization and sanitation to prevent contamination of specimen. Also designed for asepsis in assembly, injection of specimen, and exchange of medium.

  3. Birefringent hollow core fibers

    DEFF Research Database (Denmark)

    Roberts, John

    2007-01-01

    Hollow core photonic crystal fiber (HC-PCF), fabricated according to a nominally non-birefringent design, shows a degree of un-controlled birefringence or polarization mode dispersion far in excess of conventional non polarization maintaining fibers. This can degrade the output pulse in many...... and an increased overlap between the polarization modes at the glass interfaces. The interplay between these effects leads to a wavelength for optimum polarization maintenance, lambda(PM), which is detuned from the wavelength of highest birefringence. By a suitable fiber design involving antiresonance of the core...

  4. Birefringent hollow core fibers

    DEFF Research Database (Denmark)

    Roberts, John

    2007-01-01

    Hollow core photonic crystal fiber (HC-PCF), fabricated according to a nominally non-birefringent design, shows a degree of un-controlled birefringence or polarization mode dispersion far in excess of conventional non polarization maintaining fibers. This can degrade the output pulse in many...... and an increased overlap between the polarization modes at the glass interfaces. The interplay between these effects leads to a wavelength for optimum polarization maintenance, lambda(PM), which is detuned from the wavelength of highest birefringence. By a suitable fiber design involving antiresonance of the core...

  5. Hollow-Core Fiber Lamp

    Science.gov (United States)

    Yi, Lin (Inventor); Tjoelker, Robert L. (Inventor); Burt, Eric A. (Inventor); Huang, Shouhua (Inventor)

    2016-01-01

    Hollow-core capillary discharge lamps on the millimeter or sub-millimeter scale are provided. The hollow-core capillary discharge lamps achieve an increased light intensity ratio between 194 millimeters (useful) and 254 millimeters (useless) light than conventional lamps. The capillary discharge lamps may include a cone to increase light output. Hollow-core photonic crystal fiber (HCPCF) may also be used.

  6. Hollow-core grating fiber

    Science.gov (United States)

    Barillé, R.; Tajalli, P.; Roy, P.; Ahmadi-kandjani, S.; Kucharski, S.; Ortyl, E.

    2012-02-01

    We propose a new type of hollow-core fiber where the propagation is ensured by a photoinduced self-pattern acting as a surface relief grating (SRG). The SRG is written by launching a suitable laser beam with proper polarization in a capillary glass fiber with the inner surface previously coated with an azopolymer thin film. Such a grating acts as a wavelength/angle dependant reflective mirror and enhances the confinement and the propagation of the light.

  7. Cyclodextrin purification with hollow fibers

    Energy Technology Data Exchange (ETDEWEB)

    Berthod, A. (Univ. de Lyon 1, Villeubranne Cedex (France)); Jin, Heng Liang,; Armstrong, D.W. (Univ. of Missouri, Rolla (USA))

    1991-01-01

    Cyclodextrins are cyclic 1-4 linked oligomers of {alpha}-D-glucopyranose prepared from starch hydrolysis through enzymatic reactions. Mixtures of the three main cyclodextrins (CD), {alpha}-, {beta}-, and {gamma}-CDs, are always produced. A possible facile purification process is proposed. Permeation through hollow fibers made of a perfluorinated ionomer membrane. Nafion type, is shown to be an effective way to separate {alpha}-CD from {beta}- and {gamma}-CD. {Alpha}-CD with 95% purity was obtained after permeation through a Nafion hollow fiber of an equimolar 0.02 M solution of the three CDs. The fiber had a 56 cm{sup 2}/cm{sup 3} surface area per volume ratio. Kinetic studies and continuous extraction experiments with a 2-m coiled fiber showed that it is possible to obtain a 11.5 g {alpha}-CD solution with 92.4% purity or a 0.6 g {alpha}-CD solution with 97.2% purity, depending on the flow rate. The transport of CDs through the membrane could be due to moving water pools inside the ionomer. The small {alpha}-CD fits easily in such pools when the large {beta}- and {gamma}-CDs are excluded by steric hindrance. Temperature raises increased the permeation rates while decreasing the selectivity. The process could be scaled-up associating hollow fibers in bundle.

  8. Adsorption characteristics of activated carbon hollow fibers

    OpenAIRE

    2009-01-01

    Carbon hollow fibers were prepared with regenerated cellulose or polysulfone hollow fibers by chemical activation using sodium phosphate dibasic followed by the carbonization process. The activation process increases the adsorption properties of fibers which is more prominent for active carbone fibers obtained from the cellulose precursor. Chemical activation with sodium phosphate dibasic produces an active carbon material with both mesopores and micropores.

  9. Hollow fibers for compact infrared gas sensors

    Science.gov (United States)

    Lambrecht, A.; Hartwig, S.; Herbst, J.; Wöllenstein, J.

    2008-02-01

    Hollow fibers can be used for compact infrared gas sensors. The guided light is absorbed by the gas introduced into the hollow core. High sensitivity and a very small sampling volume can be achieved depending on fiber parameters i.e. attenuation, flexibility, and gas exchange rates. Different types of infrared hollow fibers including photonic bandgap fibers were characterized using quantum cascade lasers and thermal radiation sources. Obtained data are compared with available product specifications. Measurements with a compact fiber based ethanol sensor are compared with a system simulation. First results on the detection of trace amounts of the explosive material TATP using hollow fibers and QCL will be shown.

  10. Purification of nanoparticles by hollow fiber diafiltration

    Science.gov (United States)

    Veeken, J.

    2012-09-01

    Hollow Fiber Diafiltration (Hollow Fiber Tangential Flow Filtration) is an efficient and rapid alternative to traditional methods of nanoparticle purification such as ultracentrifugation, stirred cell filtration, dialysis or chromatography. Hollow Fiber Diafiltration can be used to purify a wide range of nanoparticles including liposomes, colloids, magnetic particles and nanotubes. Hollow Fiber Diafiltration is a membrane based method where pore size determines the retention or transmission of solution components. It is a flow process where the sample is gently circulated through a tubular membrane. With controlled replacement of the permeate or (dialysate), pure nanoparticles can be attained. Hollow Fiber Diafiltration can be directly scaled up from R&D volumes to production. By adding more membrane fibers and maintaining the operating parameters, large volumes can be processed in the same time with the same pressure, and flow dynamics as bench-scale volumes. Keywords: hollow fiber, Diafiltration, filtration, purification, tangential flow filtration.

  11. Robust outer-selective thin-film composite polyethersulfone hollow fiber membranes with low reverse salt flux for renewable salinity-gradient energy generation

    KAUST Repository

    Cheng, Zhen Lei

    2016-01-08

    This study reports outer-selective thin-film composite (TFC) hollow fiber membranes with extremely low reverse salt fluxes and robustness for harvesting salinity-gradient energy from pressure retarded osmosis (PRO) processes. Almost defect-free polyamide layers with impressive low salt permeabilities were synthesized on top of robust polyethersulfone porous supports. The newly developed TFC-II membrane shows a maximum power density of 7.81 W m−2 using 1 M NaCl and DI water as feeds at 20 bar. Reproducible data obtained in the 2nd and 3rd runs confirm its stability under high hydraulic pressure differences. Comparing to other PRO membranes reported in the literature, the newly developed membrane exhibits not only the smallest slope between water flux decline and ΔPΔP increase but also the lowest ratio of reverse salt flux to water flux. Thus, the effective osmotic driving force could be well maintained even under high pressure operations. For the first time, the effect of feed pressure buildup induced by feed flowrate was evaluated towards PRO performance. A slight increment in feed pressure buildup was found to be beneficial to water flux and power density up to 10.06 W m−2 without comprising the reverse salt flux. We believe this study may open up new perspectives on outer-selective PRO hollow fiber membranes and provide useful insights to understand and design next-generation outer-selective TFC hollow fiber membranes for osmotic power generation.

  12. Raman spectroscopy system with hollow fiber probes

    Science.gov (United States)

    Liu, Bing-hong; Shi, Yi-Wei

    2012-11-01

    A Raman remote spectroscopy system was realized using flexible hollow optical fiber as laser emittion and signal collection probes. A silver-coated hollow fiber has low-loss property and flat transmission characteristics in the visible wavelength regions. Compared with conventional silica optical fiber, little background fluorescence noise was observed with optical fiber as the probe, which would be of great advantages to the detection in low frequency Raman shift region. The complex filtering and focusing system was thus unnecessary. The Raman spectra of CaCO3 and PE were obtained by using the system and a reasonable signal to noise ratio was attained without any lens. Experiments with probes made of conventional silica optical fibers were also conducted for comparisons. Furthermore, a silver-coated hollow glass waveguide was used as sample cell to detect liquid phase sample. We used a 6 cm-long hollow fiber as the liquid cell and Butt-couplings with emitting and collecting fibers. Experiment results show that the system obtained high signal to noise ratio because of the longer optical length between sample and laser light. We also give the elementary theoretical analysis for the hollow fiber sample cell. The parameters of the fiber which would affect the system were discussed. Hollow fiber has shown to be a potential fiber probe or sample cell for Raman spectroscopy.

  13. Mode characteristics of hollow core Bragg fiber

    Institute of Scientific and Technical Information of China (English)

    Minning Ji; Zhidong Shi; Qiang Guo

    2005-01-01

    Analytical expression to calculate propagation constant and mode field of the hollow core Bragg fiber is derived. Numerical results are presented. It is shown that the fundamental mode of the hollow core Bragg fiber is circularly symmetric TE01 mode with no polarization degeneracy, while the higher order mode may be HE11, TM01, or TE02 etc.. This property is different from conventional optical fiber that its fundamental mode is the linearly polarized HE11 mode and is polarization degeneracy.

  14. Hollow antiresonant fibers with reduced attenuation.

    Science.gov (United States)

    Belardi, Walter; Knight, Jonathan C

    2014-04-01

    An improved design for hollow antiresonant fibers (HAFs) is presented. It consists of adding extra antiresonant glass elements within the air cladding region of an antiresonant hollow-core fiber. We use numerical simulations to compare fiber structures with and without the additional cladding elements in the near- and mid-IR regimes. We show that realizable fiber structures can provide greatly improved performance in terms of leakage and bending losses compared to previously reported antiresonant fibers. At mid-IR wavelengths, the adoption of this novel fiber design will lead to HAFs with reduced bending losses. In the near-IR, this design could lead to the fabrication of HAFs with very low attenuation.

  15. Transmission properties of hollow-core photonic bandgap fibers

    DEFF Research Database (Denmark)

    Falk, Charlotte Ijeoma; Hald, Jan; Petersen, Jan C.

    2010-01-01

    Variations in optical transmission of four types of hollow-core photonic bandgap fibers are measured as a function of laser frequency. These variations influence the potential accuracy of gas sensors based on molecular spectroscopy in hollow-core fibers.......Variations in optical transmission of four types of hollow-core photonic bandgap fibers are measured as a function of laser frequency. These variations influence the potential accuracy of gas sensors based on molecular spectroscopy in hollow-core fibers....

  16. Experimental evaluation of a hollow glass fiber.

    Science.gov (United States)

    Bornstein, A; Croitoru, N

    1986-02-01

    Very high interest in making a low-loss fiber for the infrared has been stimulated by important applications in optical communication, surgery, cutting, welding, and heat treatment. The leaky waveguide is one of the most promising types of future fiber in the infrared region where low-loss materials are not available or not suitable for making fibers (i.e., CO2 laser light lambda = 10.6 microm). In this paper a comparative model of a He-Ne laser beam and an oxide glass leaky hollow fiber for a CO2 laser light beam and a chalcogenide glass leaky hollow fiber are studied. Measurements of attenuation, dependence of output power on diameter and angle, and the angular dependence of output angle vs input angle were made. The experimental data were compared with theoretical calculations, and the critical value of the wall thickness for minimum attenuation is given.

  17. Anti-resonant hexagram hollow core fibers.

    Science.gov (United States)

    Hayes, John R; Poletti, Francesco; Abokhamis, Mousavi S; Wheeler, Natalie V; Baddela, Naveen K; Richardson, David J

    2015-01-26

    Various simple anti-resonant, single cladding layer, hollow core fiber structures are examined. We show that the spacing between core and jacket glass and the shape of the support struts can be used to optimize confinement loss. We demonstrate the detrimental effect on confinement loss of thick nodes at the strut intersections and present a fabricated hexagram fiber that mitigates this effect in both straight and bent condition by presenting thin and radially elongated nodes. This fiber has loss comparable to published results for a first generation, multi-cladding ring, Kagome fiber with negative core curvature and has tolerable bend loss for many practical applications.

  18. Generation of a hollow laser beam by a multimode fiber

    Institute of Scientific and Technical Information of China (English)

    Hongyu Ma; Huadong Cheng; Wenzhuo Zhang; Liang Liu; Yuzhu Wang

    2007-01-01

    A simple method to generate a hollow laser beam by multimode fiber is reported. A dark hollow laser beam is generated from a multimode fiber and the dependence of the output beam profile on the incident angle of laser beam is analyzed. The results show that this hollow laser beam can be used to trap and guide cold atoms.

  19. Chalcogenide glass hollow core photonic crystal fibers

    Science.gov (United States)

    Désévédavy, Frédéric; Renversez, Gilles; Troles, Johann; Houizot, Patrick; Brilland, Laurent; Vasilief, Ion; Coulombier, Quentin; Traynor, Nicholas; Smektala, Frédéric; Adam, Jean-Luc

    2010-09-01

    We report the first hollow core photonic crystal fibers (HC PCF) in chalcogenide glass. To design the required HC PCF profiles for such high index glass, we use both band diagram analysis to define the required photonic bandgap and numerical simulations of finite size HC PCFs to compute the guiding losses. The material losses have also been taken into account to compute the overall losses of the HC PCF profiles. These fibers were fabricated by the stack and draw technique from TeAsSe (TAS) glass. The fibers we drew in this work are composed of six rings of holes and regular microstructures. Two profiles are presented, one is known as a kagome lattice and the other one corresponds to a triangular lattice. Geometrical parameters are compared to the expected parameters obtained by computation. Applications of such fibers include power delivery or fiber sensors among others.

  20. Chalcogenide glass hollow core microstructured optical fibers

    Science.gov (United States)

    Shiryaev, Vladimir S.

    2015-03-01

    The recent developments on chalcogenide glass hollow core microstructured optical fibers (HC-MOFs) are presented. The comparative analysis of simulated optical properties for chalcogenide HC-MOFs of negative-curvature with different size and number of capillaries is given. The technique for the manufacture of microstructured chalcogenide preforms, which includes the assembly of the substrate glass tube and 8-10 capillaries, is described. Further trends to improve the optical transmission in chalcogenide NCHCFs are considered.

  1. Dual-core antiresonant hollow core fibers.

    Science.gov (United States)

    Liu, Xuesong; Fan, Zhongwei; Shi, Zhaohui; Ma, Yunfeng; Yu, Jin; Zhang, Jing

    2016-07-25

    In this work, dual-core antiresonant hollow core fibers (AR-HCFs) are numerically demonstrated, based on our knowledge, for the first time. Two fiber structures are proposed. One is a composite of two single-core nested nodeless AR-HCFs, exhibiting low confinement loss and a circular mode profile in each core. The other has a relatively simple structure, with a whole elliptical outer jacket, presenting a uniform and wide transmission band. The modal couplings of the dual-core AR-HCFs rely on a unique mechanism that transfers power through the air. The core separation and the gap between the two cores influence the modal coupling strength. With proper designs, both of the dual-core fibers can have low phase birefringence and short modal coupling lengths of several centimeters.

  2. New cobweb-structure hollow Bragg optical fibers

    Institute of Scientific and Technical Information of China (English)

    YU Rong-jin; ZHANG Yong-qiang; ZHANG Bing; WANG Chao-ran; WU Chang-qi

    2007-01-01

    A new type of Bragg fibers,i.e. hollow-core cobweb-structured optical fibers,which can be used to the low-loss transmission from visible to near infrared region (0.65 μm-1.55 μm),terahertz wave (200 μm-480 μm) and circular-polarization-maintaining single-mode transmission are investigated. Results show that the hollow-core cobweb-structured fibers have less loss than other hollow-core Bragg fibers. The fibers can be constituted by using the plastics or glasses with large absorption losses.

  3. Hollow fiber bioreactor technology for tissue engineering applications.

    Science.gov (United States)

    Eghbali, Hadis; Nava, Michele M; Mohebbi-Kalhori, Davod; Raimondi, Manuela T

    2016-01-01

    Hollow fiber bioreactors are the focus of scientific research aiming to mimic physiological vascular networks and engineer organs and tissues in vitro. The reason for this lies in the interesting features of this bioreactor type, including excellent mass transport properties. Indeed, hollow fiber bioreactors allow limitations to be overcome in nutrient transport by diffusion, which is often an obstacle to engineer sizable constructs in vitro. This work reviews the existing literature relevant to hollow fiber bioreactors in organ and tissue engineering applications. To this purpose, we first classify the hollow fiber bioreactors into 2 categories: cylindrical and rectangular. For each category, we summarize their main applications both at the tissue and at the organ level, focusing on experimental models and computational studies as predictive tools for designing innovative, dynamic culture systems. Finally, we discuss future perspectives on hollow fiber bioreactors as in vitro models for tissue and organ engineering applications.

  4. Air Separation Using Hollow Fiber Membranes

    Science.gov (United States)

    Huang, Stephen E.

    2004-01-01

    The NASA Glenn Research Center in partnership with the Ohio Aerospace Institute provides internship programs for high school and college students in the areas of science, engineering, professional administrative, and other technical areas. During the summer of 2004, I worked with Dr. Clarence T. Chang at NASA Glenn Research Center s combustion branch on air separation using hollow fiber membrane technology. . In light of the accident of Trans World Airline s flight 800, FAA has mandated that a suitable solution be created to prevent the ignition of fuel tanks in aircrafts. In order for any type of fuel to ignite, three important things are needed: fuel vapor, oxygen, and an energy source. Two different ways to make fuel tanks less likely to ignite are reformulating the fuel to obtain a lower vapor pressure for the fuel and or using an On Board Inert Gas Generating System (OBIGGS) to inert the Central Wing Tank. goal is to accomplish the mission, which means that the Air Separation Module (ASM) tends to be bulky and heavy. The primary goal for commercial aviation companies is to transport as much as they can with the least amount of cost and fuel per person, therefore the ASM must be compact and light as possible. The plan is to take bleed air from the aircraft s engines to pass air through a filter first to remove particulates and then pass the air through the ASM containing hollow fiber membranes. In the lab, there will be a heating element provided to simulate the temperature of the bleed air that will be entering the ASM and analysis of the separated air will be analyzed by a Gas Chromatograph/Mass Spectrometer (GC/MS). The GUMS will separate the different compounds in the exit streams of the ASM and provide information on the performance of hollow fiber membranes. Hopefully I can develop ways to improve efficiency of the ASM. different types of jet fuel were analyzed and data was well represented on SAE Paper 982485. Data consisted of the concentrations of over

  5. Hollow-core tapered coupler for large inner diameter hollow-core optical fibers

    Institute of Scientific and Technical Information of China (English)

    Guiyao Zhou(周桂耀); Zhiyun Hou(侯峙云); Lantian Hou(侯蓝田); Jigang Liu(刘继刚)

    2003-01-01

    A novel hollow-core tapered coupler has been theoretically designed and fabricated by fiber drawing machine. The coupler's inner wall is coated with a polycrystalline GeO2 film. The coupling loss of hollow-core tapered coupler is about 0.2 dB. Hollow-core tapered coupler reduces the transmission loss of hollow-core optical fiber (HCOF) by 0.5 dB/m, therefore the coupler is suitable for coupling high power CO2 laser in industrial application.

  6. Hollow infrared fibers fabricated by glass-drawing technique.

    Science.gov (United States)

    Matsuura, Yuji; Kasahara, Ryosuke; Katagiri, Takashi; Miyagi, Mitsunobu

    2002-06-17

    Hollow glass fibers for delivery of mid-infrared lasers are drawn from a glass-tube preform to produce a long and flexible hollow fiber at low cost. To utilize the interference effect of the thin glass wall, the wall thickness is controlled by the drawing speed. A Pyrex-glass hollow fiber with an inner diameter of 280 microm and a wall thickness of 9.92 microm shows a low loss at 2.94 microm of the Er:YAG laser wavelength when coated with a silver film on the outer surface.

  7. Highly efficient fluorescence sensing with hollow core photonic crystal fibers

    OpenAIRE

    Smolka, Stephan; Barth, Michael; Benson, Oliver

    2008-01-01

    We investigate hollow core photonic crystal fibers for ultra-sensitive fluorescence detection by selectively infiltrating the central hole with fluorophores. Dye concentrations down to 10(-9) M can be detected using only nanoliter sample volumes.

  8. Preparation of Polyvinylidene Fluoride (PVDF Hollow Fiber Hemodialysis Membranes

    Directory of Open Access Journals (Sweden)

    Qinglei Zhang

    2014-02-01

    Full Text Available In this study, the polyvinylidene fluoride (PVDF hollow fiber hemodialysis membranes were prepared by non-solvent induced phase separation (NIPS. The influences of PVDF membrane thickness and polyethylene glycol (PEG content on membrane morphologies, pore size, mechanical and permeable performance were investigated. It was found that membrane thickness and PEG content affected both the structure and performance of hollow fiber membranes. The tensile strength and rejection of bovine serum albumin (BSA increased with increasing membrane thickness, while the Ultrafiltration flux (UF flux of pure water was the opposite. The tensile strength, porosity and rejection of BSA increased with increasing PEG content within a certain range. Compared with commercial F60S membrane, the PVDF hollow fiber membrane showed higher mechanical and permeable performance. It was proven that PVDF material had better hydrophilicity and lower BSA adsorption, which was more suitable for hemodialysis. All the results indicate that PVDF hollow fiber membrane is promising as a hemodialysis membrane.

  9. Polyazole hollow fiber membranes for direct contact membrane distillation

    KAUST Repository

    Maab, Husnul

    2013-08-07

    Porous hollow fiber membranes were fabricated from fluorinated polyoxadiazole and polytriazole by a dry-wet spinning method for application in desalination of Red Sea water by direct contact membrane distillation (DCMD). The data were compared with commercially available hollow fiber MD membranes prepared from poly(vinylidene fluoride). The membranes were characterized by electron microscopy, liquid entry pressure (LEP), and pore diameter measurements. Finally, the hollow fiber membranes were tested for DCMD. Salt selectivity as high as 99.95% and water fluxes as high as 35 and 41 L m -2 h-1 were demonstrated, respectively, for polyoxadiazole and polytriazole hollow fiber membranes, operating at 80 C feed temperature and 20 C permeate. © 2013 American Chemical Society.

  10. Hollow fiber adsorbents for CO2 capture: Kinetic sorption performance

    KAUST Repository

    Lively, Ryan P.

    2011-07-01

    We describe a CO 2 capture platform based on hollow polymeric fibers with sorbent particles embedded in the porous fiber wall for post-combustion CO 2 capture. These fibers are intended for use in a rapid temperature swing adsorption (RTSA) process. The RTSA system utilizes the hollow fiber morphology by flowing cooling water on the bore-side of the fibers during sorption to prevent temperature rise associated with the sorption enthalpy. Steam or hot water is flowed through the bores during desorption to desorb CO 2 rapidly. To minimize material transfer between the bore and the fiber wall, a dense Neoprene ® lumen layer is cast on the bore-side of the fiber wall. In this paper, the key sorption step and associated kinetic resistances for the uncooled fibers are examined and evaluated for this portion of the RTSA process. Chopped fibers in a packed bed, as well as fibers assembled into a parallel flow module, have been tested in a simulated flue gas stream. Kinetic limitations in the hollow fiber modules are largely overcome by increasing the superficial gas velocity and the fiber packing in the module-indicating that film diffusion is the controlling mass transfer limitation in the fiber system. The un-cooled fiber modules lose apparent capacity as superficial velocities are increased, likely indicating non-isothermal operation, whereas the actively-cooled fibers in the packed bed maintain apparent capacity at all flowrates studied. © 2011 Elsevier B.V.

  11. Hollow-core fibers for high power pulse delivery

    DEFF Research Database (Denmark)

    Michieletto, Mattia; Lyngsø, Jens K.; Jakobsen, Christian;

    2016-01-01

    We investigate hollow-core fibers for fiber delivery of high power ultrashort laser pulses. We use numerical techniques to design an anti-resonant hollow-core fiber having one layer of non-touching tubes to determine which structures offer the best optical properties for the delivery of high power...... picosecond pulses. A novel fiber with 7 tubes and a core of 30 mu m was fabricated and it is here described and characterized, showing remarkable low loss, low bend loss, and good mode quality. Its optical properties are compared to both a 10 mu m and a 18 mu m core diameter photonic band gap hollow......-core fiber. The three fibers are characterized experimentally for the delivery of 22 picosecond pulses at 1032nm. We demonstrate flexible, diffraction limited beam delivery with output average powers in excess of 70W. (C) 2016 Optical Society of America...

  12. Highly efficient fluorescence sensing with hollow core photonic crystal fibers

    DEFF Research Database (Denmark)

    Smolka, Stephan; Barth, Michael; Benson, Oliver

    2008-01-01

    We investigate hollow core photonic crystal fibers for ultra-sensitive fluorescence detection by selectively infiltrating the central hole with fluorophores. Dye concentrations down to 10(-9) M can be detected using only nanoliter sample volumes.......We investigate hollow core photonic crystal fibers for ultra-sensitive fluorescence detection by selectively infiltrating the central hole with fluorophores. Dye concentrations down to 10(-9) M can be detected using only nanoliter sample volumes....

  13. Hollow polycarbonate fiber for Er:YAG laser light delivery.

    Science.gov (United States)

    Nakazawa, Masayuki; Shi, Yi-Wei; Matsuura, Yuji; Iwai, Katsumasa; Miyagi, Mitsunobu

    2006-05-15

    We developed hollow fibers with polycarbonate (PC) capillaries for use as a supporting tube. The PC capillaries were prepared by using a glass-drawing technique. Hollow PC fibers are safer and more flexible than hollow glass fibers because no fragments are released when the fibers are broken in various applications. Inner coating layers of silver and cyclic olefin polymer (COP) enhanced the reflection rate at the Er:YAG laser light wavelength. Using these fibers, we attained low loss for Er:YAG laser light transmission. By adjusting the drawing temperature in the fabrication of the PC capillaries, we created a smooth inner surface and uniform PC capillaries. We also demonstrated low-loss properties for visible pilot beams.

  14. Convection and radiation effects in hollow, compound optical fibers

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, J.I. [Room I-320-D, ETS Ingenieros Industriales, Universidad de Malaga, Plaza El Ejido, s/n, 29013 Malaga (Spain)

    2005-09-01

    A coupled model for the study of hollow, compound optical fiber drawing processes that accounts for the heat transfer in the preform and fiber and for the motion of the gases surrounding the preform and fiber by means of two-dimensional equations, employs a net radiative model for the radiative heat exchanges amongst the preform, fiber, irises and furnace walls, and uses asymptotic one-dimensional equations for the geometry, axial velocity component and temperature along the fiber for small Biot numbers is presented. It is shown that the coupled model predicts that radiative heat exchanges are about three times larger than forced convection effects, and free convection is not important. It is also shown that the fiber's geometry, axial velocity and temperature predicted by the coupled model are in remarkable good agreement with those obtained with only the one-dimensional model for hollow, compound fibers using a properly chosen constant Biot number. The results of the one-dimensional model for hollow, compound fibers show that, as the heat transfer losses from the fiber increase, the fiber's dynamic viscosity increases, the fiber exhibits a strong necking phenomenon and the fiber's axial velocity increases rapidly from its value at the die's exit to a constant value downstream and then remains constant. For the boundary conditions considered in this paper, it is shown that the activation energies of the viscosity laws for the inner and outer materials of the hollow, compound fiber do not have very strong effects on the fiber's geometry, axial velocity component and temperature, whereas the fiber's solidification point moves towards the die as the thermal Peclet number is decreased. It is also shown that the pre-exponential factor and activation energy of the dynamic viscosity law do not play a key role in determining the fiber's geometry and temperature for the conditions analyzed in this paper. (authors)

  15. Mode Division Multiplexing Exploring Hollow-Core Photonic Bandgap Fibers

    DEFF Research Database (Denmark)

    Xu, Jing; Lyngso, Jens Kristian; Leick, Lasse

    2013-01-01

    We review our recent exploratory investigations on mode division multiplexing using hollow-core photonic bandgap fibers (HC-PBGFs). Compared with traditional multimode fibers, HC-PBGFs have several attractive features such as ultra-low nonlinearities, low-loss transmission window around 2 µm etc....

  16. Interference Cancellation for Hollow-Core Fiber Reference Cells

    DEFF Research Database (Denmark)

    Seppä, Jeremias; Merimaa, Mikko; Manninen, Albert

    2015-01-01

    Doppler-free saturated absorption spectroscopy of gases in hollow-core fiber (HCF)-based cells can be used for realizing new compact, robust, and portable frequency standards. In this paper, methods for cancelling interferences resulting from the optical connections between standard fiber and HCF...

  17. Integrally skinned polysulfone hollow fiber membranes for pervaporation

    NARCIS (Netherlands)

    Koops, G.H.; Nolten, J.A.M.; Mulder, M.H.V.; Smolders, C.A.

    1994-01-01

    From polysulfone as polymer, integrally skinned hollow fiber membranes with a defect-free top layer have been spun. The spinning process described here differs from the traditional dry-wet spinning process where the fiber enters the coagulation bath after passing a certain air gap. In the present pr

  18. Integrally Skinned Polysulfone Hollow Fiber Membranes for Pervaporation

    NARCIS (Netherlands)

    Koops, G.H.; Nolten-Oude Hendrikman, J.A.M.; Nolten, J.A.M.; Mulder, M.H.V.; Smolders, C.A.; Smolders, C.A.

    1994-01-01

    From polysulfone as polymer, integrally skinned hollow fiber membranes with a defect-free top layer have been spun. The spinning process described here differs from the traditional dry-wet spinning process where the fiber enters the coagulation bath after passing a certain air gap. In the present pr

  19. Soft-glass hollow-core photonic crystal fibers

    Science.gov (United States)

    Melnikov, Leonid; Khromova, Irina; Scherbakov, Andrey; Nikishin, Nikolay

    2005-09-01

    The results of numerical modeling and experimental investigations of manufactured diamond-shaped and large area hollow core photonic crystal fibers with periodical cladding (kagome-lattice and closely packed tubes) are presented. The use of soft glasses allows to fabricate high-quality structures with moderate losses. Numerical methods, designing strategies and fabrication issues of these promising fiber structures are discussed.

  20. Soliton formation in hollow-core photonic bandgap fibers

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper

    2009-01-01

    of an approximate scaling relation is tested. It is concluded that compression of input pulses of several ps duration and sub-MW peak power can lead to a formation of solitons with ∼100 fs duration and multi-megawatt peak powers. The dispersion slope of realistic hollow-core fibers appears to be the main obstacle......The formation of solitons upon compression of linearly chirped pulses in hollow-core photonic bandgap fibers is investigated numerically. The dependence of soliton duration on the chirp and power of the input pulse and on the dispersion slope of the fiber is investigated, and the validity...

  1. Inhibited coupling hollow-core photonic crystal fiber

    Science.gov (United States)

    Benabid, F.; Gérôme, F.; Vincetti, L.; Debord, B.; Alharbi, M.; Bradley, T.

    2014-02-01

    We review the recent progress on the enhanced inhibited coupling in kagome hollow-core photonic crystal fiber by introducing negative curvature in the fiber-core shape. We show that increasing the hypocycloid contour curvature leads to a dramatic decrease in transmission loss and optical overlap with the silica surround and to a single modedness. Fabricated hypocycloid-core hollow-core photonic crystal fibers with a transmission loss in the range of 20-40 dB/km and for a spectral range of 700 nm-2000 nm have now become typical.

  2. Optical properties of end-sealed hollow fibers.

    Science.gov (United States)

    Mohri, Shintaro; Kasai, Takao; Abe, Yukio; Shi, Yi-Wei; Matsuura, Yuji; Miyagi, Mitsunobu

    2002-03-01

    We propose sealing techniques for medical hollow fibers to protect the inner surface of fibers from debris or water that scatters from targets. First, hollow fibers are sealed with a film of polymer that is easily formed by use of a dipping technique. The transmission loss of 20-microm-thick sealing film was 0.2 dB for Er:YAG laser light, and the maximum energy that is available for the film was 180 mJ. Second, a sealed glass cap was applied to the output end of hollow fiber. The silica-glass cap with a wall thickness of 400 microm shows a transmission loss of 0.5 dB and was not damaged by radiation of 400-mJ energy pulses.

  3. Photonic bandgap narrowing in conical hollow core Bragg fibers

    Energy Technology Data Exchange (ETDEWEB)

    Ozturk, Fahri Emre; Yildirim, Adem; Kanik, Mehmet [UNAM-National Nanotechnology Research Center, Bilkent University, 06800 Ankara (Turkey); Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara (Turkey); Bayindir, Mehmet, E-mail: bayindir@nano.org.tr [UNAM-National Nanotechnology Research Center, Bilkent University, 06800 Ankara (Turkey); Institute of Materials Science and Nanotechnology, Bilkent University, 06800 Ankara (Turkey); Department of Physics, Bilkent University, 06800 Ankara (Turkey)

    2014-08-18

    We report the photonic bandgap engineering of Bragg fibers by controlling the thickness profile of the fiber during the thermal drawing. Conical hollow core Bragg fibers were produced by thermal drawing under a rapidly alternating load, which was applied by introducing steep changes to the fiber drawing speed. In conventional cylindrical Bragg fibers, light is guided by omnidirectional reflections from interior dielectric mirrors with a single quarter wave stack period. In conical fibers, the diameter reduction introduced a gradient of the quarter wave stack period along the length of the fiber. Therefore, the light guided within the fiber encountered slightly smaller dielectric layer thicknesses at each reflection, resulting in a progressive blueshift of the reflectance spectrum. As the reflectance spectrum shifts, longer wavelengths of the initial bandgap cease to be omnidirectionally reflected and exit through the cladding, which narrows the photonic bandgap. A narrow transmission bandwidth is particularly desirable in hollow waveguide mid-infrared sensing schemes, where broadband light is coupled to the fiber and the analyte vapor is introduced into the hollow core to measure infrared absorption. We carried out sensing simulations using the absorption spectrum of isopropyl alcohol vapor to demonstrate the importance of narrow bandgap fibers in chemical sensing applications.

  4. Failure Mechanisms of Hollow Fiber Supported Ionic Liquid Membranes.

    Science.gov (United States)

    Zeh, Matthew; Wickramanayake, Shan; Hopkinson, David

    2016-03-23

    Hollow fiber supported ionic liquid membranes (SILMs) were tested using the bubble point method to investigate potential failure modes, including the maximum transmembrane pressure before loss of the ionic liquid from the support. Porous hollow fiber supports were fabricated with different pore morphologies using Matrimid(®) and Torlon(®) as the polymeric material and 1-hexyl-3-methylimidalzolium bis(trifluoromethylsulfonyl)imide ([C₆mim][Tf₂N]) as the ionic liquid (IL) component. Hollow fiber SILMs were tested for their maximum pressure before failure, with pressure applied either from the bore side or shell side. It was found that the membranes exhibited one or more of three different modes of failure when pressurized: liquid loss (occurring at the bubble point), rupture, and collapse.

  5. Fabrication of Polyacrylonitrile Hollow Fiber Membranes from Ionic Liquid Solutions

    KAUST Repository

    Kim, Dooli

    2015-10-08

    The interest in green processes and products has increased to reduce the negative impact of many industrial processes to the environment. Solvents, which play a crucial role in the fabrication of membranes, need to be replaced by sustainable and less toxic solvent alternatives for commonly used polymers. The purpose of this study is the fabrication of greener hollow fiber membranes based on polyacrylonitrile (PAN), substituting dimethylformamide (DMF) by less toxic mixtures of ionic liquids (IL) and dimethylsulfoxide (DMSO). A thermodynamic analysis was conducted, estimating the Gibbs free energy of mixing to find the most convenient solution compositions. Hollow fiber membranes were manufactured and optimized. As a result, a uniform pattern and high porosity were observed in the inner surface of the membranes prepared from the ionic liquid solutions. The membranes were coated with a polyamide layer by interfacial polymerization the hollow fiber membranes were applied in forward osmosis experiments by using sucrose solutions as draw solution.

  6. All-optical photoacoustic imaging system using fiber ultrasound probe and hollow optical fiber bundle.

    Science.gov (United States)

    Miida, Yusuke; Matsuura, Yuji

    2013-09-23

    An all-optical 3D photoacoustic imaging probe that consists of an optical fiber probe for ultrasound detection and a bundle of hollow optical fibers for excitation of photoacoustic waves was developed. The fiber probe for ultrasound is based on a single-mode optical fiber with a thin polymer film attached to the output end surface that works as a Fabry Perot etalon. The input end of the hollow fiber bundle is aligned so that each fiber in the bundle is sequentially excited. A thin and flexible probe can be obtained because the probe system does not have a scanning mechanism at the distal end.

  7. Extruded single ring hollow core optical fibers for Raman sensing

    Science.gov (United States)

    Tsiminis, G.; Rowland, K. J.; Ebendorff-Heidepriem, H.; Spooner, N. A.; Monro, T. M.

    2014-05-01

    In this work we report the fabrication of the first extruded hollow core optical fiber with a single ring of cladding holes. A lead-silicate glass billet is used to produce a preform through glass extrusion to create a larger-scale version of the final structure that is subsequently drawn to an optical fiber. The simple single suspended ring structure allows antiresonance reflection guiding. The resulting fibers were used to perform Raman sensing of liquid samples filling the length of the fiber, demonstrating its potential for fiber sensing applications.

  8. Hollow multilayer photonic bandgap fibers for NIR applications

    Science.gov (United States)

    Kuriki, Ken; Shapira, Ofer; Hart, Shandon D.; Benoit, Gilles; Kuriki, Yuka; Viens, Jean F.; Bayindir, Mehmet; Joannopoulos, John D.; Fink, Yoel

    2004-04-01

    Here we report the fabrication of hollow-core cylindrical photonic bandgap fibers with fundamental photonic bandgaps at near-infrared wavelengths, from 0.85 to 2.28 μm. In these fibers the photonic bandgaps are created by an all-solid multilayer composite meso-structure having a photonic crystal lattice period as small as 260 nm, individual layers below 75 nm and as many as 35 periods. These represent, to the best of our knowledge, the smallest period lengths and highest period counts reported to date for hollow PBG fibers. The fibers are drawn from a multilayer preform into extended lengths of fiber. Light is guided in the fibers through a large hollow core that is lined with an interior omnidirectional dielectric mirror. We extend the range of materials that can be used in these fibers to include poly(ether imide) (PEI) in addition to the arsenic triselenide (As2Se3) glass and poly(ether sulfone) (PES) that have been used previously. Further, we characterize the refractive indices of these materials over a broad wavelength range (0.25 - 15 μm) and incorporated the measured optical properties into calculations of the fiber photonic band structure and a preliminary loss analysis.

  9. Fabrication of a Polyamide/Polysulfone Hollow Fiber Composite Membrane

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu-feng; LIANG Chang-liang; DU Qi-yun; XIAO Chang-fa; YU Hong-liang

    2005-01-01

    With microporous polysulfone hollow fiber as the substrate,a polypiperazine amide nanofiltration composite membrane was prepared by interfacial polymerization in trimesoyl hexane solution as oil phase and piperazine aqueous solution as water phase. The conditions of the preparation, such as concentrations of monomer solutions, reaction time and temperature, annealing treatment, etc., were investigated.The hollow fiber composite herewith obtained showed high performance with water fluxes over 40 L · m-2 · hr-1 and MgSO4 rejection of 93% under a pressure of 0. 40 MPa.

  10. Hollow-Core Photonic Band Gap Fibers for Particle Acceleration

    Energy Technology Data Exchange (ETDEWEB)

    Noble, Robert J.; Spencer, James E.; /SLAC; Kuhlmey, Boris T.; /Sydney U.

    2011-08-19

    Photonic band gap (PBG) dielectric fibers with hollow cores are being studied both theoretically and experimentally for use as laser driven accelerator structures. The hollow core functions as both a longitudinal waveguide for the transverse-magnetic (TM) accelerating fields and a channel for the charged particles. The dielectric surrounding the core is permeated by a periodic array of smaller holes to confine the mode, forming a photonic crystal fiber in which modes exist in frequency pass-bands, separated by band gaps. The hollow core acts as a defect which breaks the crystal symmetry, and so-called defect, or trapped modes having frequencies in the band gap will only propagate near the defect. We describe the design of 2-D hollow-core PBG fibers to support TM defect modes with high longitudinal fields and high characteristic impedance. Using as-built dimensions of industrially-made fibers, we perform a simulation analysis of the first prototype PBG fibers specifically designed to support speed-of-light TM modes.

  11. Hollow-core photonic band gap fibers for particle acceleration

    Directory of Open Access Journals (Sweden)

    Robert J. Noble

    2011-12-01

    Full Text Available Photonic band gap (PBG dielectric fibers with hollow cores are being studied both theoretically and experimentally for use as laser driven accelerator structures. The hollow core functions as both a longitudinal waveguide for the transverse-magnetic (TM accelerating fields and a channel for the charged particles. The dielectric surrounding the core is permeated by a periodic array of smaller holes to confine the mode, forming a photonic crystal fiber in which modes exist in frequency passbands, separated by band gaps. The hollow core acts as a defect which breaks the crystal symmetry, and so-called defect, or trapped modes having frequencies in the band gap will only propagate near the defect. We describe the design of 2D hollow-core PBG fibers to support TM defect modes with high longitudinal fields and high characteristic impedance. Using as-built dimensions of industrially made fibers, we perform a simulation analysis of prototype PBG fibers with dimensions appropriate for speed-of-light TM modes.

  12. Breaking the glass ceiling: hollow OmniGuide fibers

    Science.gov (United States)

    Johnson, Steven G.; Ibanescu, Mihai; Skorobogatiy, Maksim A.; Weisberg, Ori; Engeness, Torkel D.; Soljacic, Marin; Jacobs, Steven A.; Joannopoulos, John D.; Fink, Yoel

    2002-04-01

    We argue that OmniGuide fibers, which guide light within a hollow core by concentric multilayer films having the property of omnidirectional reflection, have the potential to lift several physical limitations of silica fibers. We show how the strong confinement in OmniGuide fibers greatly suppresses the properties of the cladding materials: even if highly lossy and nonlinear materials are employed, both the intrinsic losses and nonlinearities of silica fibers can be surpassed by orders of magnitude. This feat, impossible to duplicate in an index-guided fiber with existing materials, would open up new regimes for long-distance propagation and dense wavelength-division multiplexing (DWDM). The OmniGuide-fiber modes bear a strong analogy to those of hollow metallic waveguides; from this analogy, we are able to derive several general scaling laws with core radius. Moreover, there is strong loss discrimination between guided modes, depending upon their degree of confinement in the hollow core: this allows large, ostensibly multi-mode cores to be used, with the lowest-loss TE01 mode propagating in an effectively single-mode fashion. Finally, because this TE01 mode is a cylindrically symmetrical ('azimuthally' polarized) singlet state, it is immune to polarization-mode dispersion (PMD), unlike the doubly-degenerate linearly-polarized modes in silica fibers that are vulnerable to birefringence.

  13. Hollow fiber clinostat for simulating microgravity in cell culture

    Science.gov (United States)

    Rhodes, Percy H. (Inventor); Miller, Teresa Y. (Inventor); Snyder, Robert S. (Inventor)

    1992-01-01

    A clinostat for simulating microgravity on cell systems carried in a fiber fixedly mounted in a rotatable culture vessel is disclosed. The clinostat is rotated horizontally along its longitudinal axis to simulate microgravity or vertically as a control response. Cells are injected into the fiber and the ends of the fiber are sealed and secured to spaced end pieces of a fiber holder assembly which consists of the end pieces, a hollow fiber, a culture vessel, and a tension spring with three alignment pins. The tension spring is positioned around the culture vessel with its ends abutting the end pieces for alignment of the spring. After the fiber is secured, the spring is decompressed to maintain tension on the fiber while it is being rotated. This assures that the fiber remains aligned along the axis of rotation. The fiber assembly is placed in the culture vessel and culture medium is added. The culture vessel is then inserted into the rotatable portion of the clinostat and subjected to rotate at selected rpms. The internal diameter of the hollow fiber determines the distance the cells are from the axis of rotation.

  14. Radiation trapping inside a hollow-core photonic crystal fiber

    CERN Document Server

    Jen, H H; Lee, Kevin C J; Chen, Yi-Hsin; Yu, Ite A

    2014-01-01

    We report the radiation trapping effect inside a hollow-core photonic crystal fiber (PCF). An optical dipole trap was used to load and confine the atoms in the PCF without contacting the wall of the fiber. The transmission of a probe light propagating through the PCF was studied experimentally and theoretically. With the experimental results and theoretical predictions, we conclude that the radiation trapping can play a significant role and should be taken into account in the spectroscopic measurements inside the PCF.

  15. Polymer-coated hollow fiber for CO(2) laser delivery.

    Science.gov (United States)

    Abe, Y; Matsuura, Y; Shi, Y W; Wang, Y; Uyama, H; Miyagi, M

    1998-01-15

    Hollow fibers for CO(2) laser light have been fabricated with a cyclic olefin polymer as the inner dielectric. A film of cyclic olefin polymer was coated inside the glass capillary tubing by a simple liquid-flowing process. A polymer-coated fiber with a 700-microm bore showed a loss of 0.06 dB/m for CO(2) laser light because cyclic olefin polymer has low absorption at a 10.6-microm wavelength.

  16. Core–Shell Electrospun Hollow Aluminum Oxide Ceramic Fibers

    OpenAIRE

    2015-01-01

    In this work, core–shell electrospinning was employed as a simple method for the fabrication of composite coaxial polymer fibers that became hollow ceramic tubes when calcined at high temperature. The shell polymer solution consisted of polyvinyl pyrollidone (PVP) in ethanol mixed with an aluminum acetate solution to act as a ceramic precursor. The core polymer was recycled polystyrene to act as a sacrificial polymer that burned off during calcination. The resulting fibers were analyzed wit...

  17. Synthesis of Porous Inorganic Hollow Fibers without Harmful Solvents

    NARCIS (Netherlands)

    Shukla, S.; Wit, de Patrick; Luiten-Olieman, Mieke W.J.; Kappert, Emiel J.; Nijmeijer, Arian; Benes, Nieck E.

    2015-01-01

    A route for the fabrication of porous inorganic hollow fibers with high surface-area-to-volume ratio that avoids harmful solvents is presented. The approach is based on bio-ionic gelation of an aqueous mixture of inorganic particles and sodium alginate during wet spinning. In a subsequent thermal tr

  18. A new spinning technique for hollow fiber ultrafiltration membranes

    NARCIS (Netherlands)

    Wienk, I.M.; Wienk, I.M.; Teunis, Hermannus A.; van den Boomgaard, Anthonie; Smolders, C.A.; Smolders, C.A.

    1993-01-01

    A new spinning technique for hollow fiber membranes with a densified outer toplayer has been developed in our laboratory. This technique makes use of a new type of spinneret having three concentric orifices. Apart from polymer solution and bore liquid as applied in classical spinnerets a third liqui

  19. Sustainable Route to Inorganic Porous Hollow Fibers with Superior Properties

    NARCIS (Netherlands)

    Hussein Qasim Hussein, H.Q.H.; de Wit, Patrick; Kappert, Emiel; Benes, Nieck Edwin

    2015-01-01

    This research article presents a method for the fabrication of inorganic porous hollow fibers, using ecologically benign feed materials instead of organic solvents and harmful additives. Our method is based on ionic cross-linking of an aqueous mixture of sodium alginate, inorganic particles, and a c

  20. Sustainable Route to Inorganic Porous Hollow Fibers with Superior Properties

    NARCIS (Netherlands)

    Hussein Qasim Hussein, H.Q.H.; de Wit, Patrick; Kappert, Emiel; Benes, Nieck Edwin

    2015-01-01

    This research article presents a method for the fabrication of inorganic porous hollow fibers, using ecologically benign feed materials instead of organic solvents and harmful additives. Our method is based on ionic cross-linking of an aqueous mixture of sodium alginate, inorganic particles, and a

  1. Spinning of hollow fiber ultrafiltration membranes from a polymer blend

    NARCIS (Netherlands)

    Wienk, I.M.; Wienk, I.M.; Olde scholtenhuis, F.H.A.; van den Boomgaard, Anthonie; Smolders, C.A.; Smolders, C.A.

    1995-01-01

    In this study the dry-wet spinning technique is used for the preparation of hollow fiber membranes. In the polymer solution a blend of two polymers, poly(ether sulfone) and poly(vinyl pyrrolidone), is used. The morphology of the membranes obtained is related to rheological characteristics and phase

  2. Highly permeable and mechanically robust silicon carbide hollow fiber membranes

    NARCIS (Netherlands)

    de Wit, Patrick; Kappert, Emiel; Lohaus, T.; Wessling, Matthias; Nijmeijer, Arian; Benes, Nieck Edwin

    2015-01-01

    Silicon carbide (SiC) membranes have shown large potential for applications in water treatment. Being able to make these membranes in a hollow fiber geometry allows for higher surface-to-volume ratios. In this study, we present a thermal treatment procedure that is tuned to produce porous silicon

  3. Highly permeable and mechanically robust silicon carbide hollow fiber membranes

    NARCIS (Netherlands)

    Wit, de P.; Kappert, Emiel J.; Lohaus, T.; Wessling, M.; Nijmeijer, A.; Benes, N.E.

    2015-01-01

    Silicon carbide (SiC) membranes have shown large potential for applications in water treatment. Being able to make these membranes in a hollow fiber geometry allows for higher surface-to-volume ratios. In this study, we present a thermal treatment procedure that is tuned to produce porous silicon ca

  4. Design and fabrication of inner-selective thin-film composite (TFC) hollow fiber modules for pressure retarded osmosis (PRO)

    KAUST Repository

    Wan, Chun Feng

    2016-08-03

    Pressure retarded osmosis (PRO) is a promising technology to harvest the renewable osmotic energy from salinity gradients. There are great progresses in the fabrication of PRO membranes in the last decade. Thin-film composite (TFC) hollow fibers have been widely studied and demonstrated superior performance. However, the lack of effective TFC hollow fiber modules hinders the commercialization of the PRO technology. Knowledge and experiences to fabricate TFC hollow fiber modules remain limited in the open literature. In this study, we aim to reveal the engineering and science on how to fabricate TFC hollow fiber modules including the formation of inner-selective polyamide layers and the repair of leakages. TFC-PES hollow fiber modules with 30% and 50% packing densities have been successfully fabricated, showing peak power densities of 20.0 W/m2 and 19.4 W/m2, respectively, at 20 bar using 1 M NaCl solution and DI water as feeds. The modules may be damaged during handling and high pressure testing. The repaired modules have a power density of 18.2 W/m2, 91% of the power densities of the undamaged ones. This study would make up the gap between TFC membrane fabrication and TFC membrane module fabrication in the membrane industry. © 2016 Elsevier B.V.

  5. Preparation and characterization of alumina hollow fiber membranes

    Institute of Scientific and Technical Information of China (English)

    Tao WANG; Yuzhong ZHANG; Guangfen LI; Hong LI

    2009-01-01

    With the rapid development of membrane technology in water treatment, there is a growing demand for membrane products with high performance. The inorganic hollow fiber membranes are of great interest due to their high resistance to abrasion, chemical/thermal degradation, and higher surface area/volume ratio therefore they can be utilized in the fields of water treatment. In this study, the alumina (Al2O3) hollow fiber membranes were prepared by a combined phase-inversion and sintering method. The organic binder solution (dope) containing suspended Al2O3 powders was spun to a hollow fiber precursor, which was then sintered at elevated tempera-tures in order to obtain the Al2O3 hollow fiber membrane. The dope solution consisted ofpolyethersulfone (PES), N-methyl-2-pyrrolidone (NMP) and polyvinylpyrrolidone (PVP), which were used as polymer binder, solvent and additive, respectively. The prepared Al2O3 hollow fiber membranes were characterized by a scanning electron microscope (SEM) and thermal gravimetric analysis (TG). The effects of the sintering temperature and Al2O3/PES ratios on the morphological structure, pure water flux, pore size and porosity of the membranes were also investigated extensively. The results showed that the pure water flux, maximum pore size and porosity of the prepared membranes decreased with the increase in Al2O3/PES ratios and sintering temperature. When the Al2O3/PES ratio reached 9, the pure water flux and maximum pore size were at 2547L/m2·h and 1.4μm, respectively. Under 1600℃ of sintering temperature, the pure water flux and maximum pore size reached 2398 L/(m2·h) and 2.3 μm, respectively. The results showed that the alumina hollow fiber membranes we prepared were suitable for the microfiltration process. The morphology investigation also revealed that the prepared Al2O3 hollow fiber membrane retained its'asymmetric structure even after the sintering process.

  6. Hollow fiber apparatus and use thereof for fluids separations and heat and mass transfers

    Science.gov (United States)

    Bikson, Benjamin; Etter, Stephen; Ching, Nathaniel

    2014-06-10

    A hollow fiber device includes a hollow fiber bundle, comprising a plurality of hollow fibers, a first tubesheet and a second tubesheet encapsulating respective distal ends of the hollow fiber bundle. The tubesheets have boreholes in fluid communication with bores of the hollow fibers. In at least one of the tubesheets, the boreholes are formed radially. The hollow fiber device can be utilized in heat exchange, in gas/gas, liquid/liquid and gas/liquid heat transfer, in combined heat and mass transfer and in fluid separation assemblies and processes. The design disclosed herein is light weight and compact and is particularly advantageous when the pressure of a first fluid introduced into the bores of hollow fibers is higher than the pressure on the shell side of the device.

  7. Towards Rydberg quantum optics in a hollow core fiber

    Science.gov (United States)

    Noaman, Mohammad; Langbecker, Maria; Windpassinger, Patrick

    2016-05-01

    Cold atoms inside hollow-core fibers present a promising candidate to study strongly coupled light-matter systems. Adding coherent quantum state control and the intriguing features of Rydberg atoms, i.e. long range dipolar interactions leading to a dipole blockade, to the system should allow for the generation of exotic polaritonic and photonic states. This talk will review the current status of our experimental setup where laser cooled Rubidium atoms are transported into a hollow-core fiber. We present the first measurements of Rydberg EIT in the dipole trap in front of the fiber and discuss the progress towards Rydberg physics in a quasi-one-dimensional geometry. This work is supported by FP7, Marie Curie ITN 317485, QTea.

  8. High-power picosecond pulse delivery through hollow core photonic band gap fibers

    DEFF Research Database (Denmark)

    Michieletto, Mattia; Johansen, Mette Marie; Lyngsø, Jens Kristian;

    2015-01-01

    We demonstrated robust and bend insensitive fiber delivery of high power pulsed laser with diffraction limited beam quality for two different kind of hollow core photonic band gap fibers......We demonstrated robust and bend insensitive fiber delivery of high power pulsed laser with diffraction limited beam quality for two different kind of hollow core photonic band gap fibers...

  9. Accurate modelling of fabricated hollow-core photonic bandgap fibers.

    Science.gov (United States)

    Fokoua, Eric Numkam; Sandoghchi, Seyed Reza; Chen, Yong; Jasion, Gregory T; Wheeler, Natalie V; Baddela, Naveen K; Hayes, John R; Petrovich, Marco N; Richardson, David J; Poletti, Francesco

    2015-09-07

    We report a novel approach to reconstruct the cross-sectional profile of fabricated hollow-core photonic bandgap fibers from scanning electron microscope images. Finite element simulations on the reconstructed geometries achieve a remarkable match with the measured transmission window, surface mode position and attenuation. The agreement between estimated scattering loss from surface roughness and measured loss values indicates that structural distortions, in particular the uneven distribution of glass across the thin silica struts on the core boundary, have a strong impact on the loss. This provides insight into the differences between idealized models and fabricated fibers, which could be key to further fiber loss reduction.

  10. Optical fiber modulator derivates from hollow optical fiber with suspended core.

    Science.gov (United States)

    Yang, Xinghua; Liu, Yanxin; Tian, Fengjun; Yuan, Libo; Liu, Zhihai; Luo, Shenzi; Zhao, Enming

    2012-06-01

    A fiber optic integrated modulation-depth-tunable modulator based on a type of hollow optical fiber with suspended core is proposed and investigated. We synthesized magnetic fluid containing superparamagnetic Fe(3)O(4) nanoparticles and encapsulated it in the hollow optical fiber as the cladding layer of the suspended core by fusing the hollow optical fiber with the multimode optical fibers. The light with a wavelength of 632.8 nm is coupled in and out of the modulating element by a tapering technique. Experimental results show that the light attenuation in the system can be greatly influenced by only 2.0×10(-2) μL of the magnetic fluid under different magnetic field strengths. The saturated modulation depth is 43% when the magnetic field strength is 489 Oe. The response time of the system is fiber modulators, including other integrated electro-optic devices, such as optical switch, optical fiber filter, and magnetic sensors utilizing the special structure of this hollow optical fiber with suspended core and superparamagnetic magnetic fluid.

  11. Guiding properties of kagome-lattice hollow-core fibers

    Science.gov (United States)

    Coscelli, E.; Poli, F.; Passaro, D.; Cucinotta, A.; Selleri, S.

    2010-04-01

    Photonic crystal fibers with kagome lattice are a particular kind of micostructured hollow-core fibers whose cross-section is characterized by a web of thin silica struts intersecting in a Star-of-David pattern. Such fibers show unusual properties, such as light confinement in the air-core in absence of a full photonic bandgap. The primary design parameter for such fibers is the strut thickness, which is responsible for the position and the width of the transmission bands. In this paper the guiding properties of hollow-core photonic crystal fibers with kagome lattice are investigated by means of a full-vector modal solver based on the finite element method. The fundamental mode effective index and confinement loss have been evaluated in a wide wavelength range, spanning from 300 nm to 1600 nm, accounting for the influence of the silica strut width on the transmission window. Moreover, the effects of selective alteration of the width and the shape of the silica struts surrounding the core have been analyzed. Simulation results show that the core-surrounding silica ring has the strongest effect on the transmission band, the loss level and the resonance wavelength position and, consequently, it should be carefully controlled during the fiber fabrication.

  12. Gas-Filled Hollow Core Fiber Lasers Based on Population Inversion

    Science.gov (United States)

    2013-12-05

    levels of C2H2 with the pump ( optical parametric oscillator in the telecom C band) and observed lasing transitions. The fiber ends were housed in...FA9550-10-1-0515 FA9550-10-1-0515 AFOSR unlimited Hollow-core Optical Fiber Gas LASer (HOFGLAS) have been created, and explored in pulsed mode with...were created. HOFGLAS, Optically -pumped gas lasers, photonic crystal fiber , microstructured fiber , hollow-core fiber , mid-IR lasers, IR lasers, fiber

  13. Research on polyvinylidene fluoride (PVDF) hollow-fiber hemodialyzer.

    Science.gov (United States)

    Zhang, Qinglei; Lu, Xiaolong; Zhao, Lihua; Liu, Juanjuan; Wu, Chunfeng

    2016-06-01

    In this study, polyvinylidene fluoride (PVDF) hollow-fiber hemodialysis membranes were prepared by non-solvent-induced phase separation. The PVDF hollow-fiber hemodialyzers were prepared by centrifugal casting. The results showed that the PVDF membrane had better mechanical and separation properties when the membrane wall thickness was 40 μm and the N,N-dimethylacetamide in the core was 70 Vol%. Compared with commercial polysulfone hemodialysis membrane (Fresenius F60S membrane), the PVDF membrane had better mechanical property and ultrafiltration (UF) flux of pure water. The PVDF dialyzer's removal efficiency for middle molecules was proven to be much higher than that of the F60S dialyzer. The UF coefficient of a high-flux PVDF dialyzer is 62.6 ml/h/mm Hg, whereas F60S is 42.5 ml/h/mm Hg, which can promote clearance for middle molecules.

  14. Low loss and broadband hollow-core photonic crystal fibers

    Science.gov (United States)

    Wang, Y. Y.; Gerome, F.; Humbert, G.; Blondy, J. M.; Benabid, F.

    2011-03-01

    We report on recent developments on fabrication and optical guidance of Kagome-lattice hollow-core photonic crystal fiber (HC-PCF). These include the design and fabrication of a hypocycloid-shaped core Kagome HC-PCF that combines a record optical attenuation with a baseline exhibiting ~180 dB/km over a transmission bandwidth larger than 200 THz. These results are corroborated with theoretical simulations which show that both the core-shape and the cladding ring number play role in inhibited coupling, inducing core-mode confinement for the fundamental transmission band. We also show that the inhibited coupling is weaker for the first higher-order transmission band by theoretically and experimentally comparing Kagome HC-PCF with a single anti-resonant ring hollow-core fiber.

  15. Block copolymer/homopolymer dual-layer hollow fiber membranes

    KAUST Repository

    Hilke, Roland

    2014-12-01

    We manufactured the first time block copolymer dual-layer hollow fiber membranes and dual layer flat sheet membranes manufactured by double solution casting and phase inversion in water. The support porous layer was based on polystyrene and the selective layer with isopores was formed by micelle assembly of polystyrene-. b-poly-4-vinyl pyridine. The dual layers had an excellent interfacial adhesion and pore interconnectivity. The dual membranes showed pH response behavior like single layer block copolymer membranes with a low flux for pH values less than 3, a fast increase between pH4 and pH6 and a constant high flux level for pH values above 7. The dry/wet spinning process was optimized to produce dual layer hollow fiber membranes with polystyrene internal support layer and a shell block copolymer selective layer.

  16. Integrated fiber Michelson interferometer based on poled hollow twin-core fiber.

    Science.gov (United States)

    Liu, Zhihai; Bo, Fusen; Wang, Lei; Tian, Fengjun; Yuan, Libo

    2011-07-01

    We propose an integrated fiber Michelson interferometer based on a poled hollow twin-core fiber. The Michelson interferometer can be used as an electro-optic modulator by thermal poling one core of the twin-core fiber and introducing second-order nonlinearity in the fiber. The proposed fiber Michelson interferometer is experimentally demonstrated under driving voltages at the frequency range of 149 to 1000 Hz. The half-wave voltage of the poled fiber is 135 V, and the effective second-order nonlinear coefficient χ² is 1.23 pm/V.

  17. Sol-gel processing to form doped sol-gel monoliths inside hollow core optical fiber and sol-gel core fiber devices made thereby

    Science.gov (United States)

    Shaw, Harry C. (Inventor); Ott, Melanie N. (Inventor); Manuel, Michele V. (Inventor)

    2002-01-01

    A process of fabricating a fiber device includes providing a hollow core fiber, and forming a sol-gel material inside the hollow core fiber. The hollow core fiber is preferably an optical fiber, and the sol-gel material is doped with a dopant. Devices made in this manner includes a wide variety of sensors.

  18. Sandwich-structured hollow fiber membranes for osmotic power generation

    KAUST Repository

    Fu, Feng Jiang

    2015-11-01

    In this work, a novel sandwich-structured hollow fiber membrane has been developed via a specially designed spinneret and optimized spinning conditions. With this specially designed spinneret, the outer layer, which is the most crucial part of the sandwich-structured membrane, is maintained the same as the traditional dual-layer membrane. The inner substrate layer is separated into two layers: (1) an ultra-thin middle layer comprising a high molecular weight polyvinylpyrrolidone (PVP) additive to enhance integration with the outer polybenzimidazole (PBI) selective layer, and (2) an inner-layer to provide strong mechanical strength for the membrane. Experimental results show that a high water permeability and good mechanical strength could be achieved without the expensive post treatment process to remove PVP which was necessary for the dual-layer pressure retarded osmosis (PRO) membranes. By optimizing the composition, the membrane shows a maximum power density of 6.23W/m2 at a hydraulic pressure of 22.0bar when 1M NaCl and 10mM NaCl are used as the draw and feed solutions, respectively. To our best knowledge, this is the best phase inversion hollow fiber membrane with an outer selective PBI layer for osmotic power generation. In addition, this is the first work that shows how to fabricate sandwich-structured hollow fiber membranes for various applications. © 2015 Elsevier B.V.

  19. Optical frequency standard using acetylene-filled hollow-core photonic crystal fibers

    DEFF Research Database (Denmark)

    Triches, Marco; Michieletto, Mattia; Hald, Jan

    2015-01-01

    Gas-filled hollow-core photonic crystal fibers are used to stabilize a fiber laser to the 13C2H2 P(16) (ν1+ν3) transition at 1542 nm using saturated absorption. Four hollow-core fibers with different crystal structure are compared in terms of long term lock-point repeatability and fractional...

  20. Hollow fiber membrane contactor as a gas–liquid model contactor

    NARCIS (Netherlands)

    Dindore, V.Y.; Brilman, D.W.F.; Versteeg, G.F.

    2005-01-01

    Microporous hollow fiber gas–liquid membrane contactors have a fixed and well-defined gas–liquid interfacial area. The liquid flow through the hollow fiber is laminar, thus the liquid side hydrodynamics are well known. This allows the accurate calculation of the fiber side physical mass transfer coe

  1. Hollow fiber membrane contactor as a gas-liquid model contactor

    NARCIS (Netherlands)

    Dindore, V. Y.; Brilman, D. W. F.; Versteeg, G. F.

    2005-01-01

    Microporous hollow fiber gas-liquid membrane contactors have a fixed and well-defined gas-liquid interfacial area. The liquid flow through the hollow fiber is laminar, thus the liquid side hydrodynamics are well known. This allows the accurate calculation of the fiber side physical mass transfer coe

  2. Loss mechanisms in hollow-core fibers

    DEFF Research Database (Denmark)

    Lyngsøe, Jens Kristian; Mangan, B.J.; Jakobsen, C.

    2009-01-01

    With the recent advances in digital signal processing (DSP), coherent detection is currently living its second life in the world of fiber-optics. First generation transponders using coherent detection are coming to the market, and a significant amount of research is being invested in this area. W...

  3. Core–Shell Electrospun Hollow Aluminum Oxide Ceramic Fibers

    Directory of Open Access Journals (Sweden)

    Jonathan W. Rajala

    2015-10-01

    Full Text Available In this work, core–shell electrospinning was employed as a simple method for the fabrication of composite coaxial polymer fibers that became hollow ceramic tubes when calcined at high temperature. The shell polymer solution consisted of polyvinyl pyrollidone (PVP in ethanol mixed with an aluminum acetate solution to act as a ceramic precursor. The core polymer was recycled polystyrene to act as a sacrificial polymer that burned off during calcination. The resulting fibers were analyzed with X-ray diffraction (XRD and energy dispersive spectroscopy (EDS to confirm the presence of gamma-phase aluminum oxide when heated at temperatures above 700 °C. The fiber diameter decreased from 987 ± 19 nm to 382 ± 152 nm after the calcination process due to the polymer material being burned off. The wall thickness of these fibers is estimated to be 100 nm.

  4. Silver hollow optical fibers with acrylic silicone resin coating as buffer layer for sturdy structure

    Science.gov (United States)

    Iwai, Katsumasa; Takaku, Hiroyuki; Miyagi, Mitsunobu; Shi, Yi-Wei; Zhu, Xiao-Song; Matsuura, Yuji

    2016-03-01

    For sturdy silver hollow optical fibers, acrylic silicone resin is newly used as a buffer layer between an inner silver layer and a silica capillary. This acrylic silicone resin film prevents the glass surface from chemical and mechanical micro damages during silver plating process, which deteriorate mechanical strength of the hollow fibers. In addition, it keeps high adhesion of the silver layer with the glass surface. We discuss improvement of mechanical strength of the hollow glass fibers without deterioration of optical properties.

  5. Formation and characterization of magnetic barium ferrite hollow fibers with low coercivity via co-electrospun

    Science.gov (United States)

    Liu, Gui-fang; Zhang, Zi-dong; Dang, Feng; Cheng, Chuan-bing; Hou, Chuan-xin; Liu, Si-da

    2016-08-01

    BaFe12O19 fibers and hollow fibers were successfully prepared by electrospun and co-electrospun. A very interesting result appeared in this study that hollow fibers made by co-electrospun showed low coercivity values of a few hundred oersteds, compared with the coercivity values of more than thousand oersteds for the fibers made by electrospun. So the hollow fibers with high saturation magnetization (Ms) and while comparatively low coercivity (Hc) exhibited strong magnetism and basically showed soft character. And this character for hollow fibers will lead to increase of the permeability for the samples which is favorable for impedance matching in microwave absorption. So these hollow fibers are promised to have use in a number of applications, such as switching and sensing applications, electromagnetic materials, microwave absorber.

  6. Hollow fiber membrane lumen modified by polyzwitterionic grafting

    KAUST Repository

    Le, Ngoc Lieu

    2016-08-24

    In this study, we demonstrate an effective way to modify the lumen of polyetherimide hollow fibers by grafting zwitterionic poly(sulfobetaine) to increase the membrane resistance to fouling. Surface-selective grafting of the protective hydrogel layers has been achieved in a facile two-step process. The first step is the adsorption of a macromolecular redox co-initiator on the lumen-side surface of the membrane, which in the second step, after flushing the lumen of the membrane with a solution comprising monomers and a complementary redox initiator, triggers the in situ cross-linking copolymerization at room temperature. The success of grafting reaction has been verified by the surface elemental analyses using X-ray photoelectron spectroscopy (XPS) and the surface charge evaluation using zeta potential measurements. The hydrophilicity of the grafted porous substrate is improved as indicated by the change of contact angle value from 44° to 30°, due to the hydration layer on the surface produced by the zwitterionic poly(sulfobetaine). Compared to the pristine polyetherimide (PEI) substrate, the poly(sulfobetaine) grafted substrates exhibit high fouling resistance against bovine serum albumin (BSA) adsorption, E. coli attachment and cell growth on the surface. Fouling minimization in the lumen is important for the use of hollow fibers in different processes. For instance, it is needed to preserve power density of pressure-retarded osmosis (PRO). In high-pressure PRO tests, a control membrane based on PEI with an external polyamide selective layer was seriously fouled by BSA, leading to a high water flux drop of 37%. In comparison, the analogous membrane, whose lumen was modified with poly(sulfobetaine), not only had a less water flux decline but also had better flux recovery, up to 87% after cleaning and hydraulic pressure impulsion. Clearly, grafting PRO hollow fiber membranes with zwitterionic polymeric hydrogels as a protective layer potentially sustains PRO

  7. Dual layer hollow fiber sorbents: Concept, fabrication and characterization

    KAUST Repository

    Bhandari, Dhaval

    2013-02-01

    Hollow fiber sorbents are pseudo-monolithic separations materials created with fiber spinning technology using a polymer \\'binder\\', impregnated with high loadings of sorbent \\'fillers\\' [1]. To increase purified gas recovery during the sorption step and to ensure consistent sorption capacity over repeated cycles, a dense, thin polymer barrier layer on the fiber sorbents is needed to allow only thermal interactions between the sorbate loaded layer and the thermal regeneration fluid. This paper considers materials and methods to create delamination-free dual layer fiber sorbents, with a porous core and a barrier sheath layer formed using a simultaneous co-extrusion process. Low permeability polymers were screened for sheath layer creation, with the core layer comprising cellulose acetate polymer as binder and zeolite NaY as sorbent fillers. Appropriate core and sheath layer dope compositions were determined by the cloud-point method and rheology measurements. The morphology of the as-spun fibers was characterized in detail by SEM, EDX and gas permeation analysis. A simplified qualitative model is described to explain the observed fiber morphology. The effects of core, sheath spin dope and bore fluid compositions, spinning process parameters such as air-gap height, spin dope and coagulation bath temperatures, and elongation draw ratio are examined in detail. © 2012 Elsevier B.V. All rights reserved.

  8. Few photon switching with slow light in hollow fiber

    DEFF Research Database (Denmark)

    Bajcsy, Michal; Hofferberth, S.; Balic, Vlatko

    2009-01-01

    Cold atoms confined inside a hollow-core photonic-crystal fiber with core diameters of a few photon wavelengths are a promising medium for studying nonlinear optical interactions at extremely low light levels. The high electric field intensity per photon and interaction lengths not limited...... by diffraction are some of the unique features of this system. Here, we present the results of our first nonlinear optics experiments in this system including a demonstration of an all-optical switch that is activated at energies corresponding to few hundred optical photons per pulse....

  9. Research on taper zone coupling from single-core fiber to annular-core hollow beam fiber

    Science.gov (United States)

    Tong, Chengguo; Zhang, Tao; Li, Jianqi; Wang, Pengfei; Kang, Chong; Yuan, Libo

    2016-11-01

    We designed and manufactured a novel annular-core hollow beam fiber which could directly yield ring light with a central dark spot inside the beam employing MCVD technique and a custom-made fiber drawing tower. The tapered fiber zone geometric shapes at varied stretching speed between the single-core fiber and the annular-core hollow beam fiber were studied theoretically. According to the beam propagation method, the bi-tapered coupling energy transmission between these two fibers was simulated and analyzed. Moreover, by adopting a fusion splicing and stretching technique at the fiber-linked point, an effective coupling approach had been fulfilled.

  10. Synthesis of polypiperazine-amide thin-film membrane on PPESK hollow fiber UF membrane

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new interfacial polymerization (IP) procedure is developed in order to synthesize polypiperazine-amide thin-film membrane on the inner surface of poly(phthalazinone ether sulfone ketone) (PPESK) hollow fiber ultrafiltration (UF) membrane. A hollow fiber composite membrane with good performance was prepared and studied by FT-IR and scanning electron microscopy.

  11. Low-Loss Hollow-Core Anti-Resonant Fibers With Semi-Circular Nested Tubes

    DEFF Research Database (Denmark)

    Habib, Selim; Bang, Ole; Bache, Morten

    2016-01-01

    Hollow-core fibers with a single ring of circular antiresonant tubes as the cladding provide a simple way of getting a negative-curvature hollow core, resulting in broadband low-loss transmission with little power overlap in the glass. These fibers show a significant improvement in loss performance...

  12. Attenuation measurement of infrared optical fibers by use of a hollow-taper-based coupling method.

    Science.gov (United States)

    Ilev, I K; Waynant, R W; Bonaguidi, M A

    2000-07-01

    An alternative method for attenuation measurement of infrared (IR) fibers is described. The method includes a simple technique for direct laser-to-fiber coupling with an uncoated glass hollow taper. The operating principle of the hollow taper is based on the grazing-incidence effect of light reflection. The hollow taper forms a smooth Gaussian-shaped profile of the output laser emission and provides the proper conditions for equilibrium-mode distribution of optical power within the test IR fibers. The experimental hollow-taper-based coupling method is used for measurement of attenuation and bending losses of various kinds of IR fiber, including solid-core (fluoride, chalcogenide, and germanium-doped) and hollow fibers.

  13. Dual layer hollow fiber sorbents for trace H2S removal from gas streams

    KAUST Repository

    Bhandari, Dhaval A.

    2013-05-01

    Hollow fiber sorbents are pseudo monolithic materials with potential use in various adsorption based applications. Dual layer hollow fiber sorbents have the potential to allow thermal regeneration without direct contact of the regeneration fluid with the sorbent particles. This paper considers the application of dual layer hollow fiber sorbents for a case involving trace amounts of H2S removal from a simulated gas stream and offers a comparison with single layer hollow fiber sorbents. The effect of spin dope composition and core layer zeolite loading on the gas flux, H2S transient sorption capacity and pore structure are also studied. This work can be used as a guide to develop and optimize dual layer hollow fiber sorbent properties beyond the specific example considered here. © 2013 Elsevier Ltd.

  14. Clarification of Orange Press Liquors by PVDF Hollow Fiber Membranes

    Directory of Open Access Journals (Sweden)

    Silvia Simone

    2016-01-01

    Full Text Available Press liquors are typical by-products of the citrus juice processing characterized by a high content of organic compounds and associated problems of environmental impact, which imply high treatment costs. However, these wastes contain a great number of health promoting substances, including fibers, carotenoids and phenolic compounds (mainly flavonoids, whose recovery against waste-destruction technologies is very attractive for new business opportunities. In this work, the clarification of orange press liquor by using microfiltration (MF membranes is studied as a preliminary step to obtain a permeate stream enriched in antioxidant compounds which can be further processed to produce extracts of nutraceutical and/or pharmaceutical interest. MF poly(vinylidene fluoride (PVDF hollow fibers were prepared by the dry/wet spinning technique. A series of fibers was produced from the same polymeric dope, in order to investigate the effect of selected spinning parameters, i.e., bore fluid composition and flowrate, on their properties. The morphology of the produced fibers was analyzed by Scanning Electron Microscopy (SEM. Fibers were further characterized for their mechanical properties, porosity, bubble point, pore size distribution and pure water permeability (PWP. Some of the produced fibers exhibited high permeability (pure water permeability ~530 L/m2·h·bar, coupled to good mechanical resistance and pore size in the range of MF membranes. These fibers were selected and used for the clarification of press liquor from orange peel processing. In optimized operating conditions, the selected fibers produced steady-state fluxes of about 41 L/m2·h with rejections towards polyphenols and total antioxidant activity of 4.1% and 1.4%, respectively.

  15. Hollow core anti-resonant fiber with split cladding.

    Science.gov (United States)

    Huang, Xiaosheng; Qi, Wenliang; Ho, Daryl; Yong, Ken-Tye; Luan, Feng; Yoo, Seongwoo

    2016-04-04

    An improved design for hollow core anti-resonant fibers (HAFs) is presented. A split cladding structure is introduced to reduce the fabrication distortion within design tolerance. We use numerical simulations to compare the Kagome fibers (KFs) and the proposed split cladding fibers (SCFs) over two normalized transmission bands. It reveals that SCFs are able to maintain the desired round shape of silica cladding walls, hence improving the confinement loss (CL) compared to the KF and is comparable to that of the nested antiresonant nodeless fiber (NANF) with the same core size. In addition, the SCF allows stacking multiple layers of cladding rings to control the CL. The influences of the number of cladding layers and the cladding gap width on the CL of the SCFs have been studied. SCF with three cladding rings is fabricated by the stack-and-draw technique. A measured attenuation spectrum matches well with the calculation prediction. The measured near field mode patterns also prove the feasibility of our fiber design.

  16. Fiber optic direct Raman imaging system based on a hollow-core fiber bundle

    Science.gov (United States)

    Inoue, S.; Katagiri, T.; Matsuura, Y.

    2015-03-01

    A Raman imaging system which combined a hollow fiber bundle and a direct imaging technique was constructed for high-speed endoscopic Raman imaging. The hollow fiber bundle is fabricated by depositing a silver thin film on the inner surface of pre-drawn glass capillary bundle. It performs as a fiber optic probe which transmits a Raman image with high signal-to-noise ratio because the propagating light is confined into the air core inducing little light scattering. The field of view on the sample is uniformly irradiated by the excitation laser light via the probe. The back-scattered image is collected by the probe and captured directly by an image sensor. A pair of thin film tunable filters is used to select target Raman band. This imaging system enables flexible and high-speed Raman imaging of biological tissues.

  17. A simple way to establish a dual-core hollow fiber for laser surgery applications

    Science.gov (United States)

    Jing, Chengbin; Kendall, Wesley; Harrington, James A.

    2016-03-01

    A dual-core hollow fiber has two separate cores for propagation of light. Such a fiber can have some good applications in laser surgery. The dual-core guide can transmit an infrared laser beam for cutting or ablation while a visible laser beam is simultaneously transmitted as a pilot or aiming beam. The traditional fabrication procedure for a dual-core hollow fiber involves chemical vapor deposition (CVD) growth on silica tubing of an inner cladding layer followed by the deposition of a low index polymer on the outside of the tubing. This will provide a hollow structure that has a clad-core-clad tube. This work provides an alternative approach which involves nesting of two hollow waveguides to establish a dual-core hollow fiber. An Ag/AgI hollow glass fiber is fabricated for transmitting CO2 laser. Another silica glass tube is selected carefully so that its inner diameter is just slightly larger than the outer diameter of the Ag/AgI hollow fiber. The outer surface of the as-selected glass tubing is coated with a low refractive index polymer. The Ag/AgI hollow fiber was inserted into the polymer coated silica glass tubing to establish an air or silicone oil gap between the two tubes. A visible laser beam is transmitted through the outer tube's core. The CO2 laser beam is transmitted through the inner Ag/AgI hollow fiber. The dual-core hollow fibers show good transmission for both the red aiming beam and the CO2 laser. Therefore this structure can be a good candidate for laser surgery applications.

  18. Development of a novel membrane aerated hollow-fiber microbioreactor.

    Science.gov (United States)

    Villain, Louis; Meyer, Lina; Kroll, Stephen; Beutel, Sascha; Scheper, Thomas

    2008-01-01

    A new challenge in biotechnological processes is the development of flexible bioprocessing platforms, allowing strain selection, facilitating scale-up and integrating separation steps. Miniaturization of such a cultivation system allows parallel use and the saving of resources but makes the supply of oxygen to the cells difficult. In this work we present a membrane aerated hollow-fiber microbioreactor (HFMBR) which consists of an acrylic glass module equipped with two different types of membrane fibers. Fibers of polyethersulfone and polyvinyldifluoride were used for substrate and oxygen supply, respectively. Cultivation of E. coli as model organism and production of His-tagged GFP were carried out in the extracapillary space of the membrane aerated HFMBR and compared with cultivations in shaking flask which are commonly used for screening experiments. The measurement of the oxygen transfer capacity and the online monitoring of the dissolved oxygen during the cultivation were performed using a fiber optic oxygen sensor. Online measurement of the optical density was also integrated to the bioreactor. Due to efficient oxygen transfer, a better cell growth than in the shaking flask experiments was achieved, while no negative influence on the GFP productivity was observed in the membrane aerated bioreactor. Thus the feasibility of a future integrated downstreaming could also be demonstrated.

  19. Synthesis and Preparation of Polysulfone Hollow Fiber Chelating Membrane Modified with Thiourea

    Institute of Scientific and Technical Information of China (English)

    WANG Bing; HUANG Lei; XIAO Feng

    2006-01-01

    Several kinds of chloromethyl polysulfones (CMPF) with different chlorinity and reactive groups were synthesized by Friedel-crafts reaction, which could be utilized as reactively matrix membrane materials. The CMPF hollow matrix membranes were prepared with phase inversion by utilization of CMPF/additive/DMAC casting solution and CMPF as membrane materials. It was found that the effects of additive content, bore liquid and dry spinning distance on the structure of CMPF hollow fiber matrix membrane were different. A high qualified polysulfone hollow fiber chelating membrane modified with thiourea as chelating groups was prepared using CMPF as membrane matrix materials,through the reaction between thiourea and CMPF hollow fiber matrix membrane to afford the methyl iso-thiourium polysulfone. The experimental results showed that thermal drawing could increase the mechanical properties of matrix membrane, and the thermal treatment could increase the homogeneity and stability of the structure of polysulfone hollow fiber chelating membrane modified with thiourea.

  20. Micro-displacement sensor based on a hollow-core photonic crystal fiber.

    Science.gov (United States)

    Rodrigues Pinto, Ana Margarida; Baptista, José Manuel; Santos, José Luís; Lopez-Amo, Manuel; Frazão, Orlando

    2012-12-17

    A sensing head based on a hollow-core photonic crystal fiber for in-reflection measurement of micro-displacements is presented. The sensing structure takes advantage of the multimodal behavior of a short segment of hollow-core photonic crystal fiber in-reflection, being spliced to a single mode fiber at its other end. A modal interferometer is obtained when the sensing head is close to a mirror, through which displacement is measured.

  1. Performance of different hollow fiber membranes for seawater desalination using membrane distillation

    KAUST Repository

    Francis, Lijo

    2014-08-11

    Membrane distillation requires a highly porous hydrophobic membrane with low surface energy. In this paper, we compare the direct contact membrane distillation (DCMD) performances of four different types of in-house fabricated hollow fiber membranes and two different commercially available hollow fiber membranes. Hollow fiber membranes are fabricated using wet-jet phase inversion technique and the polymeric matrices used for the fabrication are polyvinylidine fluoride (PVDF) and polyvinyl chloride (PVC). Commercial hollow fiber membrane materials are made of polytetrafluoroethylene (PTFE) and polypropylene (PP). PVDF hollow fibers showed a superior performance among all the hollow fibers tested in the DCMD process and gave a water vapor flux of 31 kg m-2h-1 at a feed and coolant inlet temperatures of 80 and 20°C, respectively. Under the same conditions, the water vapor flux observed for PP, PTFE, and PVC hollow fiber membranes are 13, 11, and 6 kg m-2h-1, respectively, with 99.99% salt rejection observed for all membranes used.

  2. Evaluation of three dry-sterilized hollow fiber artifical kidneys.

    Science.gov (United States)

    Streifel, A; Ebben, J; Sahr, C; Meyer, R; Shideman, J; Lynch, R; Kjellstrand, C

    1978-01-01

    We investigated three new dry sterilized hollow fiber artificial kidneys (HFAK) (Cordis Dow CDAK 1.3, Travenol CF 1200, Extracorporeal Tri-Ex 1). Dry sterilization makes these dialyzers more economical by shortening set-up time. Dry sterilization also eliminates iatrogenic administration of residual sterilant. Water of imbibition can significantly increase the blood compartment volume of the dialyzer during dialysis. Consequently, a corrected blood volume for each dialyzer was established; these corrected volumes varied from 13--36% greater than the volume determined before dialysate flow. With low dose heparinization of these dialyzers there was between an 18 and 45% decrease in the post dialysis volume, presumably due to fiber clotting during dialysis. This volume added to the residual blood loss measured by a colorimetric technique accounted for a possible blood loss ranging between 26.9 and 53.9 ml per dialysis for these three dialyzers. Our results suggest that a relationship between dialyzer clotting and decreased dialyzer efficiency may exist. These three capillary flow dialyzers had a much lower platelet drop (0--9% pre to post) when compared to 30--40% drop of flat plate dialyzers. These dialyzers were found to be safe and easy to use but the high fiber clotting warrants further investigation in chronic dialysis patients on high dose heparin.

  3. Ethylene glycol as bore fluid for hollow fiber membrane preparation

    KAUST Repository

    Le, Ngoc Lieu

    2017-03-31

    We proposed the use of ethylene glycol and its mixture with water as bore fluid for the preparation of poly(ether imide) (PEI) hollow fiber membranes and compared their performance and morphology with membranes obtained with conventional coagulants (water and its mixture with the solvent N-methylpyrrolidone (NMP)). Thermodynamics and kinetics of the systems were investigated. Water and 1:1 water:EG mixtures lead to fast precipitation rates. Slow precipitation is observed for both pure EG and 9:1 NMP:water mixture, but the reasons for that are different. While low osmotic driving force leads to slow NMP and water transport when NMP:water is used, the high EG viscosity is the reason for the slow phase separation when EG is the bore fluid. The NMP:water mixture produces fibers with mixed sponge-like and finger-like structure with large pores in the inner and outer layers; and hence leading to a high water permeance and a high MWCO suitable for separation of large-sized proteins. As compared to NMP:water, using EG as bore fluid provides fibers with a finger-like bilayered structure and sponge-like layers near the surfaces, and hence contributing to the higher water permeance. It also induces small pores for better protein rejection.

  4. STRUCTURE AND PROPERTIES OF COMPOSITE POLYURETHANE HOLLOW FIBER MEMBRANES

    Institute of Scientific and Technical Information of China (English)

    Xian-feng Li; Chang-fa Xiao

    2005-01-01

    Composite polyurethane (PU)-SiO2 hollow fiber membranes were successfully prepared via optimizing the technique of dry-jet wet spinning, and their pressure-responsibilities were confirmed by the relationships of pure water fluxtransmembrane pressure (PWF-TP) for the first time. The origin for this phenomenon was analyzed on the basis of membrane structure and material characteristics. The effects of SiO2 content on the structure and properties of membrane were investigated. The experimental results indicated that SiO2 in membrane created a great many interfacial micro-voids and played an important role in pressure-responsibility, PWF and rejection of membrane: with the increase of SiO2 content, the ability of membrane recovery weakened, PWF increased, and rejection decreased slightly.

  5. Studies on poly (vinyl chloride/silica dioxide composite hollow fiber membrane

    Directory of Open Access Journals (Sweden)

    Mei Shuo

    2016-01-01

    Full Text Available Poly (vinyl chloride/silica dioxide composite hollow fiber membranes were prepared by using the method of immersion-precipitation process. The influences of stretching ratio on the formation of the interfacial microporous of poly (vinyl chloride/silica dioxide composite hollow fiber membranes were specifically investigated by scanning electron microscope, dynamic mechanical analysis, and finite element method. Results show that with the stretching ratio increasing, numerous IFM appear on the surface of membranes. Finite element method actually reflects the dynamic change of microporous structure of poly (vinyl chloride/silica dioxide composite hollow fiber membranes.

  6. Electro-magnetic properties of composites with aligned Fe-Co hollow fibers

    Directory of Open Access Journals (Sweden)

    Seungchan Cho

    2016-05-01

    Full Text Available A novel Fe-Co binary hollow fiber was synthesized by electroless plating using hydrolyzed polyester fiber and its anisotropy characteristic was investigated for electromagnetic wave absorbing materials. The hollow fibers in parallel with magnetic field show higher saturated magnetization of 202 emu/g at the applied magnetic field of 10 kOe and lower coercivity (27.658 Oe, compared with the random and vertical oriented hollow fibers. From complex permittivity measurement, the Fe-Co hollow fiber composites clearly display a single dielectric resonance, located at ∼14 GHz. The Fe-Co hollow fibers not only provide excellent EM properties in GHz frequency ranges, resulting mainly from the strong resonance, but also adjust the soft magnetic properties through fiber alignments. The cavitary structure of the Fe-Co hollow fibers, not only giving rise to a dielectric loss resonance and also adjusting its peak frequency, may be a pathway to useful EM wave absorptive devices in GHz frequency ranges.

  7. High-power picosecond pulse delivery through hollow core photonic band gap fibers

    DEFF Research Database (Denmark)

    Michieletto, Mattia; Johansen, Mette Marie; Lyngsø, Jens Kristian

    2016-01-01

    We demonstrated robust and bend insensitive fiber delivery of high power laser with diffraction limited beam quality for two different kinds of hollow core band gap fibers. The light source for this experiment consists of ytterbium-doped double clad fiber aeroGAIN-ROD-PM85 in a high power amplifier...... threshold for a 19-cell hollow core photonic bandgap fiber exceeded the maximum power provided by the light source and up to 76W average output power was demonstrated for a 1m fiber. In both cases, no special attention was needed to mitigate bend sensitivity. The fibers were coiled on 8 centimeters radius...... spools and even lower bending radii were present. In addition, stimulated rotational Raman scattering arising from nitrogen molecules was measured through a 42m long 19 cell hollow core fiber. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract...

  8. Hollow-core photonic crystal fiber-optic probes for Raman spectroscopy.

    Science.gov (United States)

    Konorov, Stanislav O; Addison, Christopher J; Schulze, H Georg; Turner, Robin F B; Blades, Michael W

    2006-06-15

    We have implemented a new Raman fiber-optic probe design based on a hollow-core photonic-crystal excitation fiber surrounded by silica-core collection fibers. The photonic-crystal fiber offers low attenuation at the pump radiation wavelength, mechanical flexibility, high radiation stability, and low background noise. Because the excitation beam is transmitted through air inside the hollow-core fiber, silica Raman scattering is much reduced, improving the quality of the spectra obtained using probes of this design. Preliminary results show that the new probe design decreases the Raman background from the silica by approximately an order of magnitude compared to solid-core silica Raman probes.

  9. Switchable and tunable erbium-doped fiber lasers using a hollow-core Bragg fiber

    Science.gov (United States)

    Zhao, Tanglin; Lian, Zhenggang; Wang, Xin; Shen, Yan; Lou, Shuqin

    2016-11-01

    A switchable and tunable erbium-doped fiber laser (EDFL) is proposed and experimentally demonstrated in this paper. A novel comb filter, which consists of a section of hollow-core Bragg fiber cascaded with Sagnac loop based on a polarization-maintaining fiber (PMF), is developed to suppress the mode competition in the EDFL. By carefully adjusting the polarization controllers, switchable and tunable single- or dual-wavelength lasing outputs with side-mode suppression ratios as high as 50 dB can be achieved. Single-wavelength lasing outputs with a 3 dB linewidth of 0.02 nm can be tuned within the wavelength range from 1562.4 nm to 1565.8 nm. Two kinds of dual-wavelength lasing outputs with different wavelength intervals of 1 nm and 2.1 nm can be obtained and the corresponding tunable wavelength range is 0.5 nm. Moreover, the wavelength shift and peak power fluctuation of both the single- and dual-wavelength lasing outputs are less than 0.1 nm and 2 dB over half an hour at room temperature, which indicates that the proposed fiber laser has good stability. To the best of our knowledge, it is the first time that a hollow-core Bragg fiber has been used as a comb filter in the EDFL.

  10. Economic comparison of transverse and longitudinal flow hollow fiber membrane modules for reverse osmosis and ultrafiltration

    NARCIS (Netherlands)

    Futselaar, H.; Zoontjes, R.J.C.; Reith, T.; Racz, I.G.

    1993-01-01

    The presently used hollow fiber membrane modules consist of a bundle of fibers in a cylindrical polymer or metal shell parallel to the shell axis. The feed solution flows either through the lumen or at the outside parallel to the fibers. This paper compares the performance of these modules with a ne

  11. Depolarized guided acoustic wave Brillouin scattering in hollow-core photonic crystal fibers

    CERN Document Server

    Zhong, Wenjia Elser née; Elser, Dominique; Heim, Bettina; Marquardt, Christoph; Leuchs, Gerd

    2015-01-01

    By performing quantum-noise-limited optical heterodyne detection, we observe polarization noise in light after propagation through a hollow-core photonic crystal fiber (PCF). We compare the noise spectrum to the one of a standard fiber and find an increase of noise even though the light is mainly transmitted in air in a hollow-core PCF. Combined with our simulation of the acoustic vibrational modes in the hollow-core PCF, we are offering an explanation for the polarization noise with a variation of guided acoustic wave Brillouin scattering (GAWBS). Here, instead of modulating the strain in the fiber core as in a solid core fiber, the acoustic vibrations in hollow-core PCF influence the effective refractive index by modulating the geometry of the photonic crystal structure. This induces polarization noise in the light guided by the photonic crystal structure.

  12. Facile method of building hydroxyapatite 3D scaffolds assembled from porous hollow fibers enabling nutrient delivery

    NARCIS (Netherlands)

    Salamon, David; Da Silva Teixeira, Sandra; Dutczak, S.M.; Stamatialis, Dimitrios

    2014-01-01

    Nowadays, diffusion through scaffold and tissue usually limits transport, and forms potentially hypoxic regions. Several methods are used for preparation of 3D hydroxyapatite scaffolds, however, production of a scaffold including porous hollow fibers for nutrition delivery is difficult and

  13. Optical properties of AgI/Ag infrared hollow fiber in the visible wavelength region.

    Science.gov (United States)

    Sui, Ke-Rong; Shi, Yi-Wei; Tang, Xiao-Li; Zhu, Xiao-Song; Iwai, Katsumasa; Miyagi, Mitsunobu

    2008-02-15

    We report on AgI/Ag infrared hollow fiber with low-loss in visible region. Improved methods of silver plating and iodination were proposed to fabricate the hollow fiber. The surface roughness of the silver layer and the silver iodide layer was reduced by the pretreatment with an SnCl2 solution and low iodination temperature. Losses for the Er:YAG and green laser light were 0.4 and 7dB/m. The loss property of green laser beam was low to deliver a pilot beam for the invisible infrared laser light. Owing to the smooth and uniform AgI film, the loss spectrum of the hollow fiber showed clear interference peaks in the visible region. An empirical formula for AgI material dispersion was derived, which is of special importance for the design of high-performance AgI/Ag hollow fiber.

  14. Kinetic aspects of hollow fiber liquid-phase microextraction and electromembrane extraction

    DEFF Research Database (Denmark)

    Gjelstad, Astrid; Jensen, Henrik; Rasmussen, Knut Einar

    2012-01-01

    In this paper, extraction kinetics was investigated experimentally and theoretically in hollow fiber liquid-phase microextraction (HF-LPME) and electromembrane extraction (EME) with the basic drugs droperidol, haloperidol, nortriptyline, clomipramine, and clemastine as model analytes. In HF...

  15. Electron trajectory selection for high harmonic generation inside a short hollow fiber.

    Science.gov (United States)

    Igarashi, Hironori; Makida, Ayumu; Sekikawa, Taro

    2013-09-09

    The 19th harmonic beam divergences from a Ti:sapphire laser generated using a gas jet and 10-mm-long hollow fibers with bore diameters of 300 and 200 μm were investigated. The beam quality factor M(2) of the harmonic beam generated in a 300-μm hollow fiber was found to be better than the gas jet using the phase match including the atomic dipole phase induced by the short trajectory. On the other hand, a 200-μm hollow fiber was found to generate a more divergent beam with a larger M(2) because of the long trajectory. The electron trajectory contributing to high harmonic generation was selected using the phase-matching process inside a short hollow fiber.

  16. Fabrication of a wearable fabric tactile sensor produced by artificial hollow fiber

    Science.gov (United States)

    Hasegawa, Yoshihiro; Shikida, Mitsuhiro; Ogura, Daisuke; Suzuki, Yoshitaka; Sato, Kazuo

    2008-08-01

    An artificial-hollow-fiber structure as a new material for MEMS was developed and applied to a novel type of fabric tactile sensor. The artificial hollow fiber was fabricated by uniformly deposited metal and insulation layers on the surface of an elastic tube. A special rotating mechanism for uniformly depositing a metal layer on the tube surface during sputtering was developed. A rectangular-shaped fabric tactile sensor was produced by combining artificial hollow fibers and typical cotton yarns, like a cloth. The sensor can detect a contact force by measuring changes in capacitance at all intersection points of the artificial hollow fibers. Two different types of wearable-tactile-sensor glove, a patched type and a direct knit type, were also fabricated, and it was confirmed that both types can detect a normal load by measuring the capacitance change.

  17. Aminosilane-grafted polymer/silica hollow fiber adsorbents for CO₂ capture from flue gas.

    Science.gov (United States)

    Rezaei, Fateme; Lively, Ryan P; Labreche, Ying; Chen, Grace; Fan, Yanfang; Koros, William J; Jones, Christopher W

    2013-05-01

    Amine/silica/polymer composite hollow fiber adsorbents are produced using a novel reactive post-spinning infusion technique, and the obtained fibers are shown to capture CO2 from simulated flue gas. The post-spinning infusion technique allows for functionalization of polymer/silica hollow fibers with different types of amines during the solvent exchange step after fiber spinning. The post-spinning infusion of 3-aminopropyltrimethoxysilane (APS) into mesoporous silica/cellulose acetate hollow fibers is demonstrated here, and the materials are compared with hollow fibers infused with poly(ethyleneimine) (PEI). This approach results in silica/polymer composite fibers with good amine distribution and accessibility, as well as adequate porosity retained within the fibers to facilitate rapid mass transfer and adsorption kinetics. The CO2 adsorption capacities for the APS-infused hollow fibers are shown to be comparable to those of amine powders with similar amine loadings. In contrast, fibers that are spun with presynthesized, amine-loaded mesoporous silica powders show negligible CO2 uptake and low amine loadings because of loss of amines from the silica materials during the fiber spinning process. Aminosilica powders are shown to be more hydrophilic than the corresponding amine containing composite hollow fibers, the bare polymer as well as silica support. Both the PEI-infused and APS-infused fibers demonstrate reduced CO2 adsorption upon elevating the temperature from 35 to 80 °C, in accordance with thermodynamics, whereas PEI-infused powders show increased CO2 uptake over that temperature range because of competing diffusional and thermodynamic effects. The CO2 adsorption kinetics as probed via TGA show that the APS-infused hollow fiber adsorbents have more rapid uptake kinetics than their aminosilica powder analogues. The adsorption performance of the functionalized hollow fibers is also assessed in CO2 breakthrough experiments. The breakthrough results show a

  18. Evaluation of dialyzer jacket structure and hollow-fiber dialysis membranes to achieve high dialysis performance.

    Science.gov (United States)

    Hirano, Ayaka; Yamamoto, Ken-ichiro; Matsuda, Masato; Ogawa, Takehito; Yakushiji, Taiji; Miyasaka, Takehiro; Sakai, Kiyotaka

    2011-02-01

    The objective of this study was to determine the optimum dialyzer jacket structure and hollow-fiber dialysis membrane, both of which are indispensable factors for achieving high dialysis performance, by clarifying the relationship between the dialysis performance and the flow of dialysate and blood in a hollow-fiber dialyzer. We evaluated the clearance, dialysate, and blood flow for four commercially available hollow-fiber dialyzers, namely, the APS-15S, APS-15SA, TS-1.6UL, and CX-1.6U. To evaluate dialysate and blood flow, we measured the residence-time distribution of dialysate and blood flow of these dialyzers by the pulse-response method. We also determined the clearances of urea, creatinine, vitamin B(12), and lysozyme to evaluate the dialysis performance of these dialyzers. While the baffle and taper structures allow effective supply of dialysate into the dialyzer jacket, the hollow-fiber shape, inner diameter, and packing density significantly influence the dialysate flow. In dialyzers with long taper-holding slits, the slit area is a key design parameter for achieving optimum dialysate flow. Similarly, the blood flow is significantly influenced by the structure of the inflowing and outflowing blood ports at the header of a dialyzer, and the shape and inner diameter of the hollow fibers. Hollow fibers with smaller inner diameters cause an increase in blood pressure, which causes blood to enter the hollow fibers more easily. The hollow-fiber shape hardly affects the blood flow. While improved dialysate and blood flow cause higher clearance of low molecular-weight substances, higher membrane area and pure-water permeability accelerate internal filtration, thereby causing an increase in the clearance of large molecular-weight substances. © 2010 The Authors. Therapeutic Apheresis and Dialysis © 2010 International Society for Apheresis.

  19. Analysis of flux reduction behaviors of PRO hollow fiber membranes: Experiments, mechanisms, and implications

    KAUST Repository

    Xiong, Jun Ying

    2016-01-15

    Pressure retarded osmosis (PRO) is a promising technology to harvest renewable osmotic energy using a semipermeable membrane. However, a significant flux reduction has been always observed that severely shrinks the harvestable power to a level only marginally higher or even lower than the economically feasible value. This work focuses on the elucidation of various underlying mechanisms responsible for the flux reduction. First, both inner-selective and outer-selective thin film composite (TFC) hollow fiber membranes are employed to examine how the fundamental internal factors (such as the surface salinity of the selective layer at the feed side (CF,m) and its components) interact with one another under the fixed bulk salinity gradient, resulting in various behaviours of external performance indexes such as water flux, reverse salt flux, and power density. Then, the research is extended to investigate the effects of the growing bulk feed salinity due to the accumulated reverse salt flux along PRO modules. Finally, the insights obtained from the prior two stationary conditions are combined with the advanced nucleation theory to elucidate the dynamic scaling process by visualizing how the multiple fundamental factors (such as local supersaturation, nucleation rate and nuclei size) evolve and interplay with one another in various membrane regimes during the whole scaling process. To our best knowledge, it is the first time that the advanced nucleation theory is applied to study the PRO scaling kinetics in order to provide subtle and clear pictures of the events occurring inside the membrane. This study may provide useful insights to design more suitable TFC hollow fiber membranes and to operate them with enhanced water flux so that the PRO process may become more promising in the near future.

  20. Dynamic control of higher-order modes in hollow-core photonic crystal fibers.

    Science.gov (United States)

    Euser, T G; Whyte, G; Scharrer, M; Chen, J S Y; Abdolvand, A; Nold, J; Kaminski, C F; Russell, P St J

    2008-10-27

    We present a versatile method for selective mode coupling into higher-order modes of photonic crystal fibers, using holograms electronically generated by a spatial light modulator. The method enables non-mechanical and completely repeatable changes in the coupling conditions. We have excited higher order modes up to LP(31) in hollow-core photonic crystal fibers. The reproducibility of the coupling allows direct comparison of the losses of different guided modes in both hollow-core bandgap and kagome-lattice photonic crystal fibers. Our results are also relevant to applications in which the intensity distribution of the light inside the fiber is important, such as particle- or atom-guidance.

  1. High Power Spark Delivery System Using Hollow Core Kagome Lattice Fibers

    Directory of Open Access Journals (Sweden)

    Ciprian Dumitrache

    2014-08-01

    Full Text Available This study examines the use of the recently developed hollow core kagome lattice fibers for delivery of high power laser pulses. Compared to other photonic crystal fibers (PCFs, the hollow core kagome fibers have larger core diameter (~50 µm, which allows for higher energy coupling in the fiber while also maintaining high beam quality at the output (M2 = 1.25. We have conducted a study of the maximum deliverable energy versus laser pulse duration using a Nd:YAG laser at 1064 nm. Pulse energies as high as 30 mJ were transmitted for 30 ns pulse durations. This represents, to our knowledge; the highest laser pulse energy delivered using PCFs. Two fiber damage mechanisms were identified as damage at the fiber input and damage within the bulk of the fiber. Finally, we have demonstrated fiber delivered laser ignition on a single-cylinder gasoline direct injection engine.

  2. Block copolymer hollow fiber membranes with catalytic activity and pH-response.

    Science.gov (United States)

    Hilke, Roland; Pradeep, Neelakanda; Madhavan, Poornima; Vainio, Ulla; Behzad, Ali Reza; Sougrat, Rachid; Nunes, Suzana P; Peinemann, Klaus-Viktor

    2013-08-14

    We fabricated block copolymer hollow fiber membranes with self-assembled, shell-side, uniform pore structures. The fibers in these membranes combined pores able to respond to pH and acting as chemical gates that opened above pH 4, and catalytic activity, achieved by the incorporation of gold nanoparticles. We used a dry/wet spinning process to produce the asymmetric hollow fibers and determined the conditions under which the hollow fibers were optimized to create the desired pore morphology and the necessary mechanical stability. To induce ordered micelle assembly in the doped solution, we identified an ideal solvent mixture as confirmed by small-angle X-ray scattering. We then reduced p-nitrophenol with a gold-loaded fiber to confirm the catalytic performance of the membranes.

  3. Block copolymer hollow fiber membranes with catalytic activity and pH-response

    KAUST Repository

    Hilke, Roland

    2013-08-14

    We fabricated block copolymer hollow fiber membranes with self-assembled, shell-side, uniform pore structures. The fibers in these membranes combined pores able to respond to pH and acting as chemical gates that opened above pH 4, and catalytic activity, achieved by the incorporation of gold nanoparticles. We used a dry/wet spinning process to produce the asymmetric hollow fibers and determined the conditions under which the hollow fibers were optimized to create the desired pore morphology and the necessary mechanical stability. To induce ordered micelle assembly in the doped solution, we identified an ideal solvent mixture as confirmed by small-angle X-ray scattering. We then reduced p-nitrophenol with a gold-loaded fiber to confirm the catalytic performance of the membranes. © 2013 American Chemical Society.

  4. Highly scalable ZIF-based mixed-matrix hollow fiber membranes for advanced hydrocarbon separations

    KAUST Repository

    Zhang, Chen

    2014-05-29

    ZIF-8/6FDA-DAM, a proven mixed-matrix material that demonstrated remarkably enhanced C3H6/C3H8 selectivity in dense film geometry, was extended to scalable hollow fiber geometry in the current work. We successfully formed dual-layer ZIF-8/6FDA-DAM mixed-matrix hollow fiber membranes with ZIF-8 nanoparticle loading up to 30 wt % using the conventional dry-jet/wet-quench fiber spinning technique. The mixed-matrix hollow fibers showed significantly enhanced C3H6/C3H8 selectivity that was consistent with mixed-matrix dense films. Critical variables controlling successful formation of mixed-matrix hollow fiber membranes with desirable morphology and attractive transport properties were discussed. Furthermore, the effects of coating materials on selectivity recovery of partially defective fibers were investigated. To our best knowledge, this is the first article reporting successful formation of high-loading mixed-matrix hollow fiber membranes with significantly enhanced selectivity for separation of condensable olefin/paraffin mixtures. Therefore, it represents a major step in the research area of advanced mixed-matrix membranes. © 2014 American Institute of Chemical Engineers.

  5. Hollow Fiber Membrane Dehumidification Device for Air Conditioning System.

    Science.gov (United States)

    Zhao, Baiwang; Peng, Na; Liang, Canzeng; Yong, Wai Fen; Chung, Tai-Shung

    2015-11-16

    In order to provide a comfortable living and working environment indoors in tropical countries, the outdoor air often needs to be cooled and dehumidified before it enters the rooms. Membrane separation is an emerging technology for air dehumidification and it is based on the solution diffusion mechanism. Water molecules are preferentially permeating through the membranes due to its smaller kinetic diameter and higher condensability than the other gases. Compared to other dehumidification technologies such as direct cooling or desiccation, there is no phase transition involved in membrane dehumidification, neither the contact between the fresh air stream and the desiccants. Hence, membrane dehumidification would not only require less energy consumption but also avoid cross-contamination problems. A pilot scale air dehumidification system is built in this study which comprises nine pieces of one-inch PAN/PDMS hollow fiber membrane modules. A 150 h long-term test shows that the membrane modules has good water vapor transport properties by using a low vacuum force of only 0.78 bar absolute pressure at the lumen side. The water vapor concentration of the feed humid air decreases dramatically from a range of 18-22 g/m³ to a range of 13.5-18.3 g/m³. Most importantly, the total energy saving is up to 26.2% compared with the conventional air conditioning process.

  6. Hollow Fiber Membrane Dehumidification Device for Air Conditioning System

    Directory of Open Access Journals (Sweden)

    Baiwang Zhao

    2015-11-01

    Full Text Available In order to provide a comfortable living and working environment indoors in tropical countries, the outdoor air often needs to be cooled and dehumidified before it enters the rooms. Membrane separation is an emerging technology for air dehumidification and it is based on the solution diffusion mechanism. Water molecules are preferentially permeating through the membranes due to its smaller kinetic diameter and higher condensability than the other gases. Compared to other dehumidification technologies such as direct cooling or desiccation, there is no phase transition involved in membrane dehumidification, neither the contact between the fresh air stream and the desiccants. Hence, membrane dehumidification would not only require less energy consumption but also avoid cross-contamination problems. A pilot scale air dehumidification system is built in this study which comprises nine pieces of one-inch PAN/PDMS hollow fiber membrane modules. A 150 h long-term test shows that the membrane modules has good water vapor transport properties by using a low vacuum force of only 0.78 bar absolute pressure at the lumen side. The water vapor concentration of the feed humid air decreases dramatically from a range of 18–22 g/m3 to a range of 13.5–18.3 g/m3. Most importantly, the total energy saving is up to 26.2% compared with the conventional air conditioning process.

  7. Recovery of phenol from aqueous streams in hollow fiber modules.

    Science.gov (United States)

    Cichy, W; Szymanowski, J

    2002-05-01

    A setup with two parallel hollow-fiber modules was used to study the recovery of phenol from aqueous solutions. Cyanex 923, Amberlite LA-2, and trioctylamine (TOA) in aliphatic kerosene were used as carriers. A solution of 0.2 M NaOH was used for stripping. It was found that each of the studied carriers permitted the effective removal of phenol. Cyanex 923 showed the best performance, removing phenol in the shortest time and giving the highest fluxes and the highest mass-transfer coefficients. The maximum fluxes of phenol entering the receiving phase changed in the following ratio: Cyanex 923/Amberlite LA-2/TOA = 3.5/1.5/1. The mass-transfer coefficient in the extraction step changed in the same order: 34/5.2/1. The mass-transfer coefficients of the stripping step were 2-4 orders lower than in the extraction step and were comparable for each carrier: Cyanex 923/Amberlite LA-2/TOA = 1.1/0.7/1. Using Cyanex 923, only 5 min were needed to recover 99% of the pollutant from the aqueous stream, containing 0.5-2 g L(-1) phenol.

  8. Preparation and characterization of thermally stable copoly(phthalazinone biphenyl ether sulfone) hollow fiber ultrafiltration membranes

    Science.gov (United States)

    Liu, Peng; Zhang, Shouhai; Wang, Yutian; Lu, Yan; Jian, Xigao

    2015-04-01

    Novel thermally stable copoly(phthalazinone biphenyl ether sulfone) (PPBES) hollow fiber ultrafiltration (UF) membranes were successfully fabricated by the dry/wet phase inversion technique. The effects of polymer dope formulation (i.e., the PPBES concentration, different types and contents of additives) and fiber spinning conditions (i.e., air gap distance, coagulation bath temperature) on the morphologies and separation performance of PPBES hollow fiber UF membranes were investigated, respectively. It was found that the water flux of hollow fiber membrane decreased with the increase of PPBES concentration or EGME content in casting solution, while the rejection of PEG increased. However, the PPBES hollow fiber UF prepared with LiCl as inorganic small molecule additive exhibited different phenomena. In addition, the decrease of air gap distance or the increase of coagulation bath temperature could improve the water flux of UF membrane while reduce the rejection of PEG. Moreover, the thermal stability of the PPBES hollow fiber UF membranes was investigated. The water flux of PPBES membrane increased dramatically from 155 to 428 L m-2 h-1 without significant decrease of rejection when the temperature of feed solution increased from 20 °C to 95 °C.

  9. Hollow-fiber-supported liquid membranes with improved stability for nitrate removal

    NARCIS (Netherlands)

    Kemperman, A.J.B.; Rolevink, H.H.M.; Boomgaard, van den Th.; Strathmann, H.

    1997-01-01

    This paper describes the development of a hollow-fiber-supported liquid membrane (HFSLM) for the removal of nitrate ions from water. Two different membrane modules were designed which differed in length of the fibers. In order to test the HFSLMs on nitrate flux and stability, two set-ups were used:

  10. Fabrication of a polymer-coated silver hollow optical fiber with high performance

    Science.gov (United States)

    Shi, Yi-Wei; Ito, Kentaro; Ma, Lin; Yoshida, Takanori; Matsuura, Yuji; Miyagi, Mitsunobu

    2006-09-01

    The techniques for fabricating a hollow optical fiber with an inner silver layer and a cyclic olefin polymer (COP) layer have been improved to reduce the surface roughness of these two layers. The loss spectrum was thereby drastically reduced over a wide wavelength range, from visible to near infrared. Optimization of the COP layer thickness resulted in low loss simultaneously at several key laser wavelengths. Infrared hollow fiber with low loss was developed for Er:YAG and Nd:YAG lasers. It can also deliver green and red pilot beams with low loss. Use of this fiber in therapeutic and pilot lasers should prove useful for research and development in laser medicine.

  11. Diaphragm-free fiber-optic Fabry-Perot interferometer based on tapered hollow silica tube

    Science.gov (United States)

    Fang, Guocheng; Jia, Pinggang; Liang, Ting; Tan, Qiulin; Hong, Yingping; Liu, Wenyi; Xiong, Jijun

    2016-07-01

    A miniature fiber-optic Fabry-Perot interferometer fabricated by splicing a diaphragm-free hollow silica tube to a single-mode fiber and fusing the inner core to a taper is presented. The tapered zone forces lights to propagate from the fiber core into the silica tube, and the lights is reflected from the end faces of the optical fiber and the hollow silica tube. The contrast ratio of the interference fringe is determined by the minimum inner diameter of hollow silica tube. The responses of the proposed interferometer to high-temperature, gas refractive index, liquid refractive index and pressure were measured and were found to be linear with sensitivities of 16.26 pm/°C, 610.47 nm/RIU, -122.36 dB/RIU and 1.56 pm/kPa, respectively.

  12. Hollow fiber structures, methods of use thereof, methods of making, and pressure-retarded processes

    KAUST Repository

    Le, Lieu Ngoc

    2016-12-08

    Embodiments of the present disclosure provide for composite materials, methods of making composite materials, methods of using composite materials, and the like. In particular, the present application relates to hollow fibers and to pressure-retarded osmosis systems comprising said fibers. The hollow fibers have an inside layer and an outside layer, wherein the outside layer covers an outside surface of the inside layer, wherein the inside layer forms a boundary around the lumen, wherein the inside layer includes a bi-layer structure, wherein the bi-layer structure includes a sponge-like layer and a finger-like layer, wherein the sponge-like layer is disposed closer to the lumen of the hollow fiber and the finger-like layer is disposed on the sponge-like layer on the side opposite the lumen, wherein the outside layer includes a polyamide layer.

  13. One-Step Synthesis of Hollow Titanate (Sr/Ba Ceramic Fibers for Detoxification of Nerve Agents

    Directory of Open Access Journals (Sweden)

    Satya R. Agarwal

    2012-01-01

    Full Text Available Poly(vinyl pyrrolidone(PVP/(strontium/barium acetate/titanium isopropoxide composite fibers were prepared by electrospinning technique via sol-gel process. Diameters of fibers prepared by calcinations of PVP composite fibers were 80–140 nm (solid and 1.2-2.2 μm (hollow fibers prepared by core-shell method. These fibers were characterized using scanning electron microscope (SEM, X-ray diffraction (XRD, and transmission electron microscope (TEM analytical techniques. XRD results showed better crystalline nature of the materials when calcined at higher temperatures. SEM and TEM results clearly showed the formation of hollow submicrometer tubes. The surface area of the samples determined by BET analysis indicated that hollow fibers have ~20% higher surface area than solid fibers. The UV studies indicate better detoxification properties of the hollow fibers compared to solid fibers.

  14. Evaluation of diffusion in gel entrapment cell culture within hollow fibers

    Institute of Scientific and Technical Information of China (English)

    Dan-Qing Wu; Guo-Liang Zhang; Chong Shen; Qian Zhao; Hui Li; Qin Meng

    2005-01-01

    AIM: To investigate diffusion in mammalian cell culture by gel entrapment within hollow fibers.METHODS: Freshly isolated rat hepatocytes or human oral epidermoid carcinoma (KB) cells were entrapped in type Ⅰ collagen solutions and statically cultured inside microporous and ultrafiltration hollow fibers. During the culture time collagen gel contraction, cell viability and specific function were assessed. Effective diffusion coefficients of glucose in cell-matrix gels were determined by lag time analysis in a diffusion cell.R ESULTS: Significant gel contractions occurred in the collagen gels by entrapment of either viable hepatocytes or KB cells. And the gel contraction caused a significant reduction on effective diffusion coefficient of glucose. The cell viability assay of both hepatocytes and KB cells statically cultured in hollow fibers by collagen entrapment further confirmed the existence of the inhibited mass transfer by diffusion. Urea was secreted about 50% more by hepatocytes entrapped in hollow fibers with pore size of 0.1 pm than that in hollow fibers with MWCO of 100 ku.CONCLUSION: Cell-matrix gel and membrane pore size are the two factors relevant to the limited mass transfer by diffusion in such gel entrapment of mammalian cell culture.

  15. Pure germanium dioxide hollow-core fiber for transmitting CO2 laser

    Institute of Scientific and Technical Information of China (English)

    侯兰田; 付连符; 吕平; 韩玉华; 李秋更; 徐立宣; 李天柱

    1995-01-01

    A method of fabricating pure germanium dioxide hollow-core fibers has been introduced for the first time. The output power of the fabricated fiber can come to 18 W, with the transmission loss of 1.23 dB/m at 10.6 μm. The mechanism of transmitting CO2 laser by the fiber is analyzed, the transmitting loss is further discussed and its application fields are envisaged.

  16. Impact of structural distortions on the performance of hollow-core photonic bandgap fibers

    OpenAIRE

    2014-01-01

    We present a generic model for studying numerically the performance of hollow-core photonic bandgap fibers (HC-PBGFs) with arbitrary cross-sectional distortions. Fully vectorial finite element simulations reveal that distortions beyond the second ring of air holes have an impact on the leakage loss and bandwidth of the fiber, but do not significantly alter its surface scattering loss which remains the dominant contribution to the overall fiber loss (providing that a sufficient number of rings...

  17. Square-lattice large-pitch hollow-core photonic crystal fiber

    DEFF Research Database (Denmark)

    Couny, F.; Roberts, John; Birks, T.A.;

    2008-01-01

    We report on the design, fabrication and characterization of silica square-lattice hollow core photonic crystal fibers optimized for low loss guidance over an extended frequency range in the mid-IR region of the optical spectrum. The fiber's linear optical properties include an ultra-low group...... velocity dispersion and a polarization cross-coupling as low as -13.4dB over 10m of fiber....

  18. Characterization of hollow chemical garden fibers from metal salts and water glass

    OpenAIRE

    Balköse, Devrim; Çakıcıoğlu Özkan, Seher Fehime; Köktürk, Uğur; Ulutan, Sevgi; Ülkü, Semra; Nişli, Gürel

    2002-01-01

    Hollow fibers formed from water glass and metal salts of IIA(Ca), VIIB(Fe, Co, Ni) and IB(Cu) groups were characterised in this study. Fragile fibres obtained herein broke down into small pieces during isolation and drying. Quantitative information about morphology, chemical composition and surface structure of the fibres were obtained. The diameter and wall thickness of the fibers were around 50 μ and 3 μ. respectively. They had particulate inner and smooth outer surfaces. Fibers had variabl...

  19. Electromagnetically induced transparency in Rb-filled coated hollow-core photonic crystal fiber

    Science.gov (United States)

    Light, P. S.; Benabid, F.; Couny, F.; Maric, M.; Luiten, A. N.

    2007-05-01

    We report the observation of lambda-configuration electromagnetically induced transparency as well as optical pumping in rubidium-filled kagome-structure hollow-coated-core photonic crystal fiber. We show that a polydimethylsiloxane coating of the fiber core reduces the linewidth of the transparency below that which could be expected for an uncoated fiber. The measured 6 MHz linewidth was dominated by optical broadening.

  20. Matrimid® derived carbon molecular sieve hollow fiber membranes for ethylene/ethane separation

    KAUST Repository

    Xu, Liren

    2011-09-01

    Carbon molecular sieve (CMS) membranes have shown promising separation performance compared to conventional polymeric membranes. Translating the very attractive separation properties from dense films to hollow fibers is important for applying CMS materials in realistic gas separations. The very challenging ethylene/ethane separation is the primary target of this work. Matrimid® derived CMS hollow fiber membranes have been investigated in this work. Resultant CMS fiber showed interesting separation performance for several gas pairs, especially high selectivity for C2H4/C2H6. Our comparative study between dense film and hollow fiber revealed very similar selectivity for both configurations; however, a significant difference exists in the effective separation layer thickness between precursor fibers and their resultant CMS fibers. SEM results showed that the deviation was essentially due to the collapse of the porous substructure of the precursor fiber. Polymer chain flexibility (relatively low glass transition temperature (Tg) for Matrimid® relative to actual CMS formation) appears to be the fundamental cause of substructure collapse. This collapse phenomenon must be addressed in all cases involving intense heat-treatment near or above Tg. We also found that the defect-free property of the precursor fiber was not a simple predictor of CMS fiber performance. Even some precursor fibers with Knudsen diffusion selectivity could be transformed into highly selective CMS fibers for the Matrimid® precursor. To overcome the permeance loss problem caused by substructure collapse, several engineering approaches were considered. Mixed gas permeation results under realistic conditions demonstrate the excellent performance of CMS hollow fiber membrane for the challenging ethylene/ethane separation. © 2011 Elsevier B.V.

  1. Formation of defect-free 6FDA-DAM asymmetric hollow fiber membranes for gas separations

    KAUST Repository

    Xu, Liren

    2014-06-01

    This paper reports the formation of defect-free 6FDA-DAM asymmetric hollow fiber membranes. 6FDA-polyimides are of great interest for advanced gas separation membranes, and 6FDA-DAM polyimide is a representative polymer in this family with attractive dense film properties for several potential applications. The work reported here for the 6FDA-DAM polyimide provides insight for the challenging fabrication of defect-free asymmetric hollow fiber membranes for this class of 6FDA-polyimides, which behave rather different from lower free volume polymers. Specifically, the 6FDA based materials show relatively slow phase separation rate in water quench baths, which presents a challenge for fiber spinning. For convenience, we refer to the behavior as more "non-solvent resistant" in comparison to other lower free volume polymers, since the binodal phase boundary is displaced further from the conventional position near the pure polymer-solvent axis on a ternary phase diagram in conventional polymers like Matrimid® and Ultem®. The addition of lithium nitrate to promote phase separation has a useful impact on 6FDA-DAM asymmetric hollow fiber formation. 6FDA-DAM phase diagrams using ethanol and water as non-solvent are reported, and it was found that water is less desirable as a non-solvent dope additive for defect-free fiber spinning. Phase diagrams are also reported for 6FDA-DAM dope formulation with and without the addition of lithium nitrate, and defect-free asymmetric hollow fiber membranes are reported for both cases. The effect of polymer molecular weight on defect-free fiber spinning was also investigated. Gas transport properties and morphology of hollow fibers were characterized. With several thorough case studies, this work provides a systematic guideline for defect-free fiber formation from 6FDA-polymers. © 2014 Elsevier B.V.

  2. Optical Characterization of a Hollow Fiber Raman Probe toward Non-Invasive Measurements of Living Tissues

    Science.gov (United States)

    Mitsuoka, Hiroki; Morita, Shin-ichi; Suzuki, Toshiaki; Matsuura, Yuji; Katsumoto, Yukiteru; Sato, Hidetoshi

    2009-02-01

    The use of a hollow fiber as a Raman probe, which gives strong advantage of a free link in space, was confirmed to be a versatile and standard analytical method, since Raman data obtained through a hollow fiber probe assures a sufficient link to conventional Raman data. In this paper, we confirmed that a Raman spectrum given by the hollow fiber probe becomes identical to a Raman spectrum measured by a conventional approach, if one is multiplied by an optimized coefficient. In addition, Raman signal intensity changes were related to various types of curved geometries of the probe. The Raman signal intensity value at a curved geometry of the probe, which is one of the most frequently used positions, became 0.35 compared to the value at the standard position of the probe (straight lined).

  3. Multiwavelength laser light transmission of hollow optical fiber from the visible to the mid-infrared

    Science.gov (United States)

    Shi, Yi Wei; Ito, Kentaro; Matsuura, Yuji; Miyagi, Mitsunobu

    2005-11-01

    We report on low-loss multiwavelength laser delivery of hollow optical fiber in a wide wavelength region, from the visible to the infrared. Improved methods of liquid-phase coating were used to fabricate the hollow fiber with inner films of a silver and a cyclic olefin polymer (COP) layer. The surface roughness of the silver layer was reduced dramatically by pretreatment on the inner glass surface with an SnCl2 solution. The COP layer roughness was also decreased by using an ambient atmosphere of tetrahydrofuran (THF) solvent during the COP layer formation. Owing to the smooth surfaces, hollow fiber with optimum COP film thickness for CO2 laser light simultaneously yields low losses for a Er:YAG laser and a red pilot beam. The power durability of CO2 and Er:YAG lasers, as well as the loss properties for the pilot beam, is demonstrated.

  4. Multiwavelength laser light transmission of hollow optical fiber from the visible to the mid-infrared.

    Science.gov (United States)

    Shi, Yi Wei; Ito, Kentaro; Matsuura, Yuji; Miyagi, Mitsunobu

    2005-11-01

    We report on low-loss multiwavelength laser delivery of hollow optical fiber in a wide wavelength region, from the visible to the infrared. Improved methods of liquid-phase coating were used to fabricate the hollow fiber with inner films of a silver and a cyclic olefin polymer (COP) layer. The surface roughness of the silver layer was reduced dramatically by pretreatment on the inner glass surface with an SnCl2 solution. The COP layer roughness was also decreased by using an ambient atmosphere of tetrahydrofuran (THF) solvent during the COP layer formation. Owing to the smooth surfaces, hollow fiber with optimum COP film thickness for CO2 laser light simultaneously yields low losses for a Er:YAG laser and a red pilot beam. The power durability of CO2 and Er:YAG lasers, as well as the loss properties for the pilot beam, is demonstrated.

  5. Novel design of hollow-core multi clad fiber for long haul optical communication system

    Science.gov (United States)

    Palodiya, Vikram; Raghuwanshi, Sanjeev K.

    2016-09-01

    We have described a dispersion characteristics of hollow-core multi-clad index profiles, which include a hollow core. The designs satisfy the most important requirements for applications in long haul communication. This design fiber shows zero dispersion at 1550 nm can be obtained for the fundamental air core mode over a wide wavelength range by introducing the partial reflector layer around the core, optimizing expanded core size and silica cladding thickness. Also analyze dispersion compensating properties of these fibers. This unique structure of the fundamental air core mode is presented by the introduction of partial reflector cladding around the core. The potential applications of hollow-core multi clad fibers in long-haul optical communication system.

  6. Fabrication of ultrathin In2O3 hollow fibers for UV light sensing

    Science.gov (United States)

    Chen, Shuai; Long, Yun-Ze; Zhang, Hong-Di; Liu, Shu-Liang; Liu, Ling-Zhi; Zhang, Jun-Cheng; Liu, Guo-Xia; Shan, Fu-Kai

    2014-11-01

    Ultrathin indium oxide (In2O3) hollow fibers were successfully fabricated by electrospinning poly(vinylidene fluoride) (PVDF) nanofibers, magnetron sputtering of In2O3 on PVDF fibers followed by calcination of In2O3/PVDF composite fibers. The hollow In2O3 fibers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD) and UV-Visible spectroscopy. The outer diameter of the hollow fibers was in the range of 700-900 nm, and the inner diameter was about 400-600 nm. The optoelectronic properties of the In2O3 fibers were investigated by the irradiation of UV light with different wavelengths (254, 308 and 365 nm). It was found that the In2O3 hollow nanofibers had a fast and strong response to UV irradiation. The response time was less than 10 s, and the sensitivity (˜102) decreased with the UV light wavelength increasing or the light intensity decreasing.

  7. Hydrogen separation from multicomponent gas mixtures containing CO, N2 and CO2 using Matrimid asymmetric hollow fiber membranes

    NARCIS (Netherlands)

    David, Oana C.; Gorri, Daniel; Nijmeijer, Dorothea C.; Ortiz, Inmaculada; Urtiaga, Ane

    2012-01-01

    The application of hollow fiber membranes for the separation of industrial gas mixtures relies on the correct characterization of the permeation of the involved gaseous components through the hollow fiber membranes. Thus, this study is focused on the characterization of the permeation through

  8. Fabrication and characterization of functionally graded poly(vinylidine fluoride)-silver nanocomposite hollow fibers for sustainable water recovery

    KAUST Repository

    Francis, Lijo

    2014-12-01

    Poly(vinylidine fluoride) (PVDF) asymmetric hydrophobic hollow fibers were fabricated successfully using dryjet wet spinning. Hydrophobic silver nanoparticles were synthesized and impregnated into the PVDF polymer matrix and functionally graded PVDF-silver nanocomposite hollow fibers are fabricated and tested in the direct contact membrane distillation (DCMD) process. The as-synthesized silver nanoparticles were characterized for Transmission Electron Microscopy (TEM), particle size distribution (PSD) and Ultra Violet (UV) visible spectroscopy. Both the PVDF and PVDF-silver nanocomposite asymmetric hollow fibers were characterized for their morphology, water contact angle and mechanical strength. Addition of hydrophobic silver nanoparticles was found to enhance the hydrophobicity and ~ 2.5 fold increase the mechanical strength of the hollow fibers. A water vapor flux of 31.9kg m-2 h-1 was observed at a feed inlet temperature of 80 °C and at a permeate temperature of 20 °C in the case of hollow fiber membrane modules fabricated using PVDF hollow fibers; the water vapor flux was found to be increased by about 8% and to reach 34.6kg m-2 h-1 for the hollow fiber membrane modules fabricated from the PVDF-silver nanocomposite hollow fibers at the same operating conditions with 99.99% salt rejection.

  9. Effective enrichment of cholangiocarcinoma secretomes using the hollow fiber bioreactor culture system.

    Science.gov (United States)

    Weeraphan, Churat; Diskul-Na-Ayudthaya, Penchatr; Chiablaem, Khajeelak; Khongmanee, Amnart; Chokchaichamnankit, Daranee; Subhasitanont, Pantipa; Svasti, Jisnuson; Srisomsap, Chantragan

    2012-09-15

    The Northeastern region of Thailand is well known to have high incidence of bile duct cancer known as cholangiocarcinoma. So there is a continued need to improve diagnosis and treatment, and discovery of biomarkers for early detection of bile duct cancer should greatly improve treatment outcome for these patients. The secretome, a collection of proteins secreted from cells, is a useful source for identifying circulating biomarkers in blood secreted from cancer cells. Here a Hollow Fiber Bioreactor culture system was used for enrichment of cholangiocarcinoma secretomes, since this culture system mimics the dense three-dimensional microenvironment of the tumor found in vivo. Two-dimensional fluorescence difference gel electrophoresis using a sensitive Fluor saturation dye staining, followed by LC/MS/MS, was used to compare protein expression in the secretomes of cells cultured in the Hollow Fiber system and cells cultured in the monolayer culture system. For the first time, the 2D-patterns of cholangiocarcinoma secretomes from the two culture systems could be compared. The Hollow Fiber system improved the quality and quantity of cholangiocarcinoma secreted proteins compared to conventional monolayer system, showing less interference by cytoplasmic proteins and yielding more secreted proteins. Overall, 75 spots were analyzed by LC/MS/MS and 106 secreted proteins were identified. Two novel secreted proteins (C19orf10 and cystatin B) were found only in the Hollow Fiber system and were absent from the traditional monolayer culture system. Among the highly expressed proteins, 22 secreted soluble proteins were enriched by 5 fold in Hollow Fiber system compared to monolayer culture system. The Hollow Fiber system is therefore useful for preparing a wide range of proteins from low-abundance cell secretomes. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. A test resonator for Kagome Hollow-core Photonic Crystal Fibers for resonant rotation sensing

    Science.gov (United States)

    Fsaifes, Ihsan; Feugnet, Gilles; Ravaille, Alexia; Debord, Benoït; Gérôme, Frédéric; Baz, Assaad; Humbert, Georges; Benabid, Fetah; Schwartz, Sylvain; Bretenaker, Fabien

    2017-01-01

    We build ring resonators to assess the potentialities of Kagome Hollow-Core Photonic Crystal Fibers for future applications to resonant rotation sensing. The large mode diameter of Kagome fibers permits to reduce the free space fiber-to-fiber coupling losses, leading to cavities with finesses of about 30 for a diameter equal to 15 cm. Resonance linewidths of 3.2 MHz with contrasts as large as 89% are obtained. Comparison with 7-cell photonic band gap (PBG) fiber leads to better finesse and contrast with Kagome fiber. Resonators based on such fibers are compatible with the angular random walk required for medium to high performance rotation sensing. The small amount of light propagating in silica should also permit to further reduce the Kerr-induced non-reciprocity by at least three orders of magnitudes in 7-cell Kagome fiber compared with 7-cell PBG fiber.

  11. High-power picosecond pulse delivery through hollow core photonic band gap fibers

    Science.gov (United States)

    Michieletto, Mattia; Johansen, Mette M.; Lyngsø, Jens K.; Lægsgaard, Jesper; Bang, Ole; Alkeskjold, Thomas T.

    2016-03-01

    We demonstrated robust and bend insensitive fiber delivery of high power laser with diffraction limited beam quality for two different kinds of hollow core band gap fibers. The light source for this experiment consists of ytterbium-doped double clad fiber aeroGAIN-ROD-PM85 in a high power amplifier setup. It provided 22ps pulses with a maximum average power of 95W, 40MHz repetition rate at 1032nm (~2.4μJ pulse energy), with M2 bend sensitivity. The fibers were coiled on 8 centimeters radius spools and even lower bending radii were present. In addition, stimulated rotational Raman scattering arising from nitrogen molecules was measured through a 42m long 19 cell hollow core fiber.

  12. Single-mode hollow-core photonic crystal fiber made from soft glass

    Science.gov (United States)

    Jiang, X.; Euser, T. G.; Abdolvand, A.; Babic, F.; Tani, F.; Joly, N. Y.; Travers, J. C.; St. J. Russell, P.

    2011-08-01

    We demonstrate the first soft-glass hollow core photonic crystal fiber. The fiber is made from a high-index lead-silicate glass (Schott SF6, refractive index 1.82 at 500 nm). Fabricated by the stack-and-draw technique, the fiber incorporates a 7-cell hollow core embedded in a highly uniform 6-layer cladding structure that resembles a kagomé-like lattice. Effective single mode guidance of light is observed from 750 to 1050 nm in a large mode area (core diameter ~30 μm) with a low loss of 0.74 dB/m. The underlying guidance mechanism of the fiber is investigated using finite element modeling. The fiber is promising for applications requiring single mode guidance in a large mode area, such as particle guidance, fluid and gas filled devices.

  13. Development of potassium ion conducting hollow glass fibers. [potassium sulfur battery

    Science.gov (United States)

    Tsang, F. Y.

    1974-01-01

    Potassium ion conducting glasses, chemically resistant to potassium, potassium sulfide and sulfur, were made and their possible utility as the membrane material for a potassium/sulfur battery was evaluated. At least one satisfactory candidate was found. It possesses an electrical resistance which makes it usable as a membrane in the form of a fine hollow fiber. It's chemical and electrochemical resistances are excellent. The other aspects of the possible potassium sulfur battery utilizing such fine hollow fibers, including the header (or tube sheet) and a cathode current collector were studied. Several cathode materials were found to be satisfactory. None of the tube sheet materials studied possessed all the desired properties. Multi-fiber cells had very limited life-time due to physical failure of fibers at the fiber/tube sheet junctions.

  14. Broadband transmission in hollow-core Bragg fibers with geometrically distributed multilayered cladding.

    Science.gov (United States)

    Hu, Dora Juan Juan; Alagappan, Gandhi; Yeo, Yong-Kee; Shum, Perry Ping; Wu, Ping

    2010-08-30

    For the first time, the quasiperiodic Bragg fibers with geometrically distributed multilayered cladding are proposed and analyzed. We demonstrate that hollow-core Bragg fibers with quasiperiodic dielectric multilayer cladding can achieve low loss transmission over a broadband wavelength range of more than an octave (from 0.81 μm to 1.7 μm). The periods of the Bragg blocks follows a geometrical progression with a common ratio rcladding can significantly modify the characteristics of the fiber, leading to a broadening of the guiding range compared to a hollow Bragg fiber with uniform periodic multilayer cladding structure. In general, a larger r value results in a broader guiding range. More Bragg blocks in the cladding and more unit cells in each Bragg block lead to a lower fiber modal loss.

  15. Fabrication of an IR hollow-core Bragg fiber based on chalcogenide glass extrusion

    Science.gov (United States)

    Zhu, Minming; Wang, Xunsi; Pan, Zhanghao; Cheng, Ci; Zhu, Qingde; Jiang, Chen; Nie, Qiuhua; Zhang, Peiqing; Wu, Yuehao; Dai, Shixun; Xu, Tiefeng; Tao, Guangming; Zhang, Xianghua

    2015-05-01

    The theoretical analysis and experimental preparation of a hollow-core Bragg fiber based on chalcogenide glasses are demonstrated. The fiber has potential applications in bio-sensing and IR energy transmission. Two chalcogenide glasses with, respectively, high and low refractive indexes are investigated in detail for the fabrication of hollow-core Bragg fibers. The most appropriate structure is selected; this structure is composed of four concentric rings and a center air hole . Its band gap for the Bragg fiber is analyzed by the plane wave method. The chalcogenide glasses Ge15Sb20S58.5I13 and Ge15Sb10Se75 are chosen to extrude the robust multi-material glass preform with a specialized punch and glass container. The glass preform is simultaneously protected with a polyetherimide polymer. The hollow-core Bragg fibers are finally obtained after glass preform extrusion, fiber preform fabrication, and fiber drawing. Results showed that the fiber has a transparency window from 2.5 to 14 μm, including a low-loss transmission window from 10.5 to 12 μm. The location of this low-loss transmission window matches the predicted photonic band gap in the simulation.

  16. Study on the photonic bandgaps of hollow-core microstructured fibers

    Institute of Scientific and Technical Information of China (English)

    Zhaolun Liu; Guiyao Zhou; Lantian Hou

    2006-01-01

    A simple method is presented to measure the transmission spectrum of hollow-core microstructured fibers in the visible, near-infrared, and mid-infrared regions. The plane wave expansion method is applied to analyze the photonic bandgaps of hollow-core microstructured fibers. The experimental results indicate that there are several strong transmission bands in the near-infrared and mid-infrared region, but hardly any transmission phenomena in the visible region, which shows that there are some bandgaps in nearinfrared wavelength. The experimental results are consistent with the numerically simulative results using a plane wave expansion method.

  17. Fabrication of Polybenzimidazole/Palladium Nanoparticles Hollow Fiber Membranes for Hydrogen Purification

    KAUST Repository

    Villalobos, Luis Francisco

    2017-09-13

    A novel scheme to fabricate polybenzimidazole (PBI) hollow fiber membranes with a thin skin loaded with fully dispersed palladium nanoparticles is proposed for the first time. Palladium is added to the membrane during the spinning process in the form of ions that coordinate to the imidazole groups of the polymer. This is attractive for membrane production because agglomeration of nanoparticles is minimized and the high-cost metal is incorporated in only the selective layer—where it is required. Pd-containing membranes achieve three orders of magnitude higher H2 permeances and a twofold improvement in H2/CO2 selectivity compared to pure PBI hollow fiber membranes.

  18. Structure and Properties of Polyurethane/Polyvinylidene Difluoride Blending Hollow Fiber

    Institute of Scientific and Technical Information of China (English)

    HU Xiao-yu; XIAO Chang-fa; AN Shu-lin; WANG Zhao-xu

    2006-01-01

    Utilization of polyvinylidene difluoride, PVDF, as the disperse phase and thermal plastic polyurethane, PU, as the continuous phase, the PU/PVDF blend hollow fiber membranes with the property of pressure-responsibility,PR, was prepared by melt- spinning. For these hollow fibers, the formation of the interfacial micro-voids, IFM,and the spinability of the blend were analyzed. The pressure-responsibility was studied by measuring the changing of pure water flux, PWF, with the pressure, and the influence of drawing and heat-setting on the structure and pressure-responsibility of the membranes were also discussed.

  19. Negative Curvature Hollow-core Fibers: Dispersion Properties and Femtosecond Pulse Delivery

    Science.gov (United States)

    Kolyadin, A. N.; Alagashev, G. K.; Pryamikov, A. D.; Mouradian, L.; Zeytunyan, A.; Toneyan, H.; Kosolapov, A. F.; Bufetov, I. A.

    In this work a comparative analysis of dispersion properties of hollow core photonic crystal fibers (HC PCFs) and negative curvature hollow core fibers (NCHCFs) was carried out. It was shown that the main reason for the low dispersion slope of NCHCFs is a strong light localization in the air core in comparison with HC PCFs. The strong light localization in NCHCFs allows not to use the complicated photonic crystal cladding and to reduce the air mode interaction with silica glass elements of the cladding. This conclusion was confirmed by experimental measurement of the group velocity dispersion and femtosecond pulse transmission for the NCHCF.

  20. Hollow-fiber compression of visible, 200 fs laser pulses to 40 fs pulse duration.

    Science.gov (United States)

    Procino, I; Velotta, R; Altucci, C; Amoruso, S; Bruzzese, R; Wang, X; Tosa, V; Sansone, G; Vozzi, C; Nisoli, M

    2007-07-01

    We demonstrate the use of a very simple, compact, and versatile method, based on the hollow-fiber compression technique, to shorten the temporal length of visible laser pulses of 100-300 fs to pulse durations shorter than approximately 50 fs. In particular, 200 fs, frequency-doubled, Nd:glass laser pulses (527 nm) were spectrally broadened to final bandwidths as large as 25 nm by nonlinear propagation through an Ar-filled hollow fiber. A compact, dispersive, prism-pair compressor was then used to produce as short as 40 fs, 150 microJ pulses. A very satisfactory agreement between numerical simulations and measurements is found.

  1. Preparation of [11C]formaldehyde using a hollow fiber membrane bioreactor.

    Science.gov (United States)

    Hughes, J A; Jay, M

    1995-01-01

    A bioreactor consisting of the enzymes alcohol oxidase and catalase immobilized onto a hollow fiber membrane was used to convert [11C]methanol to [11C]formaldehyde. Using an alcohol oxidase:catalase ratio of 1:500 U, conversion yields of 90-95% were obtained allowing the production of up to 7400 MBq (200 mCi) of [11C]formaldehyde in 5 min. The hollow fiber bioreactor allowed for a convenient, rapid synthesis with yields significantly higher than the standard chemical procedures, has demonstrable advantages over glass bead immobilized systems (primarily due to convective flow), and was amenable to hot cell conditions.

  2. Light localization in hollow core fibers with a complicated shape of the core cladding boundary

    CERN Document Server

    Pryamikov, A D; Alagashev, G K

    2016-01-01

    In this paper we present a theoretical and numerical analysis of light localization in hollow core microstructured fibers (HCMFs) with a complicated shape of the core cladding boundary. The analysis is based on well established models (for example, the ARROW model) and also on the models proposed for the first time. In particular, we consider local and nonlocal mechanisms of light localization in the waveguide structures with a determined type of discrete rotational symmetry of the core cladding boundary. We interpret and analyze mechanisms of light localization in negative curvature hollow core microstructured fibers (NC HCMFs) and simplified HC PCFs with a polygonal shape of the core cladding boundary.

  3. Rapid Temperature Swing Adsorption using Polymeric/Supported Amine Hollow Fibers

    Energy Technology Data Exchange (ETDEWEB)

    Chance, Ronald [Georgia Tech Research Corporation, Atlanta, GA (United States); Chen, Grace [Georgia Tech Research Corporation, Atlanta, GA (United States); Dai, Ying [Georgia Tech Research Corporation, Atlanta, GA (United States); Fan, Yanfang [Georgia Tech Research Corporation, Atlanta, GA (United States); Jones, Christopher [Georgia Tech Research Corporation, Atlanta, GA (United States); Kalyanaraman, Jayashree [Georgia Tech Research Corporation, Atlanta, GA (United States); Kawajiri, Yoshiaki [Georgia Tech Research Corporation, Atlanta, GA (United States); Koros, William [Georgia Tech Research Corporation, Atlanta, GA (United States); Lively, Ryan [Georgia Tech Research Corporation, Atlanta, GA (United States); McCool, Benjamin [Georgia Tech Research Corporation, Atlanta, GA (United States); Pang, Simon [Georgia Tech Research Corporation, Atlanta, GA (United States); Realff, Matthew [Georgia Tech Research Corporation, Atlanta, GA (United States); Rezaei, Fateme [Georgia Tech Research Corporation, Atlanta, GA (United States); Searcy, Katherine [Georgia Tech Research Corporation, Atlanta, GA (United States); Sholl, David [Georgia Tech Research Corporation, Atlanta, GA (United States); Subramanian, Swernath [Georgia Tech Research Corporation, Atlanta, GA (United States); Pang, Simon [Georgia Tech Research Corporation, Atlanta, GA (United States)

    2015-03-31

    This project is a bench-scale, post-combustion capture project carried out at Georgia Tech (GT) with support and collaboration with GE, Algenol Biofuels, Southern Company and subcontract to Trimeric Corporation. The focus of the project is to develop a process based on composite amine-functionalized oxide / polymer hollow fibers for use as contactors in a rapid temperature swing adsorption post-combustion carbon dioxide capture process. The hollow fiber morphology allows coupling of efficient heat transfer with effective gas contacting, potentially giving lower parasitic loads on the power plant compared to traditional contacting strategies using solid sorbents.

  4. Hollow Core Fiber Optics for Mid-Wave and Long-Wave Infrared Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kriesel, J.M.; Gat, N.; Bernacki, Bruce E.; Erikson, Rebecca L.; Cannon, Bret D.; Myers, Tanya L.; Bledt, Carlos M.; Harrington, J. A.

    2011-06-01

    The development and testing of hollow core glass waveguides (i.e., fiber optics) for use in Long-Wave Infrared (LWIR) spectroscopy systems is described. LWIR fiber optics are a key enabling technology needed to improve the utility and effectiveness of trace chemical detection systems based in the 8 to 12 micron region. This paper focuses on recent developments in hollow waveguide technology geared specifically for LWIR spectroscopy, including a reduction in both the length dependent loss and the bending loss while maintaining relatively high beam quality. Results will be presented from tests conducted with a Quantum Cascade Laser.

  5. Hollow fiber membranes with different external corrugated surfaces for desalination by membrane distillation

    Science.gov (United States)

    García-Fernández, Loreto; García-Payo, Carmen; Khayet, Mohamed

    2017-09-01

    Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) hollow fiber membranes were prepared using the phase inversion spinning technique under a wet gap mode. Different corrugated outer surfaces were obtained by means of a micro-engineered spinneret, spraying the external coagulant on the nascent fiber along gap, and different spinning parameters, namely, the gap distance and the external coagulant flow rate. A quantitative evaluation of the corrugation size and shape was carried out by electron scanning microscopy and atomic force microscopy. The effect of the corrugation size and shape on the direct contact membrane distillation (DCMD) performance has been studied. The corrugated outer surface acted as micro-turbulence promoters mitigating the temperature polarization effect and enhanced the external effective surface area for condensation. Both factors improved the DCMD permeability of the hollow fiber membranes. However, corrugations with V-shaped valleys depths greater than about 30 μm did not always improve the DCMD permeate flux. It was found that the membrane prepared with the spray wetting mode exhibited the best desalination performance. The salt rejection factor of all prepared hollow fiber membranes was greater than 99.9% and the highest DCMD permeate flux of this study was greater than those reported so far for the PVDF-HFP hollow fiber membranes.

  6. Ultra-large bandwidth hollow-core guiding in all-silica bragg fibers with nano-supports

    DEFF Research Database (Denmark)

    Vienne, Guillaume; Xu, Yong; Jakobsen, Christian;

    2004-01-01

    We demonstrate a new class of hollow-core Bragg fibers that are composed of concentric cylindrical silica rings separated by nanoscale support bridges. We theoretically predict and experimentally observe hollow-core confinement over an octave frequency range. The bandwidth of bandgap guiding...... in this new class of Bragg fibers exceeds that of other hollow-core fibers reported in the literature. With only three rings of silica cladding layers, these Bragg fibers achieve propagation loss of the order of 1 dB/m....

  7. Morphological studies on the culture of kidney epithelial cells in a fiber-in-fiber bioreactor design with hollow fiber membranes.

    Science.gov (United States)

    Fey-Lamprecht, F; Albrecht, W; Groth, T; Weigel, T; Gross, U

    2003-05-01

    A hollow fiber-in-fiber-based bioreactor system was tested for the applicability to host kidney epithelial cells as a model system for a bioartificial kidney. Hollow fibers were prepared from polyacrylonitrile (PAN), polysulfone-polyvinylpyrollidinone (PVP) blend (PSU) and poly(acrylonitrile-N-vinylpyrollidinone) copolymer P(AN-NVP). Hollow fibers with smaller and larger diameters were prepared so that the smaller fitted into the larger, with a distance of 50-100 microm in between. The following material combinations as outer and inner fiber were applied: PAN-PAN; PSU-PSU, PSU-P(AN-NVP). Madin-Darby kidney epithelial cells (MDCK) were seeded in the interfiber space and cultured for a period up to 14 days. Light, scanning, and transmission electron microscopy were used to follow the adhesion and growth of cells, and to characterize their morphology. As a result, we found that MDCK cells were able to grow in the interfiber space in mono- and multilayers without signs of systemic degeneration. Comparison of the different materials showed that PAN and P(AN-NVP) provided the best growth conditions, indicated by a tight attachment of cells on hollow fiber membrane, and subsequent proliferation and development of structural elements of normal epithelia, such as tight junctions and microvilli. In conclusion, the fiber-in-fiber design seems to be an interesting system for the construction of a bioartificial kidney. Copyright 2003 Wiley Periodicals, Inc.

  8. Kagome Hollow-Core Photonic Crystal Fiber Resonator for Rotation Sensing

    CERN Document Server

    Fsaifes, Ihsan; Debord, Benoît; Gérôme, Frédéric; Baz, Assaad; Humbert, Georges; Benabid, Fetah; Schwartz, Sylvain; Bretenaker, Fabien

    2016-01-01

    We investigate the performances of a Kagome Hollow-Core Photonic Crystal Fiber resonator for rotation sensing applications. The use of a large mode field diameter Kagome fiber permits to reduce the free space fiber-to-fiber coupling losses, allowing the realization of cavities with finesses compatible with the angular random walk required for medium to high performance rotation sensing, while minimizing the Kerr effect induced non reciprocities. Experiments show encouraging results that could lead to a compact, low cost, and robust medium for high performance gyroscope.

  9. Flexible small-bore hollow fibers with an inner polymer coating.

    Science.gov (United States)

    Abe, Y; Shi, Y W; Matsuura, Y; Miyagi, M

    2000-02-01

    Flexible hollow-glass fibers with small-bore diameters of 250 and 320 mum have been developed for Er:YAG laser delivery. The fibers consist of a glass capillary tube and an inner coating of silver and polymer thin films that are deposited by use of a simple liquid-phase technique. The 250-mum-bore fiber exhibits a straight loss of 0.8 dB/m and a bending loss of 1.2 dB when it is bent 180 degrees at the output end, with a bending radius of 2 cm. The maximum energy delivered by the fibers is ~100 mJ.

  10. Cladding defects in hollow core fibers for surface mode suppression and improved birefringence.

    Science.gov (United States)

    Michieletto, M; Lyngsø, J K; Lægsgaard, J; Bang, O

    2014-09-22

    We demonstrate a novel polarization maintaining hollow-core photonic bandgap fiber geometry that reduces the impact of surface modes on fiber transmission. The cladding structure is modified with a row of partially collapsed holes to strip away unwanted surface modes. A theoretical investigation of the surface mode stripping is presented and compared to the measured performance of four 7-cells core fibers that were drawn with different collapse ratio of the defects. The varying pressure along the defect row in the cladding during drawing introduces an ellipticity of the core. This, combined with the presence of antiresonant features on the core wall, makes the fibers birefringent, with excellent polarization maintaining properties.

  11. Two-color mid-infrared thermometer with a hollow glass optical fiber.

    Science.gov (United States)

    Small, W; Celliers, P M; Da Silva, L B; Matthews, D L; Soltz, B A

    1998-10-01

    We have developed a low-temperature optical-fiber-based two-color infrared thermometer. A single 700-mum-bore hollow glass optical fiber collects and transmits radiation that is then modulated and split into two paths by a reflective optical chopper. Two different thermoelectrically cooled mid-infrared HgCdZnTe photoconductors monitor the chopped signals that are recovered with lock-in amplification. With the two previously obtained blackbody calibration equations, a computer algorithm calculates the true temperature and emissivity of a target in real time, taking into account reflection of the ambient radiation field from the target surface. The small numerical aperture of the hollow glass fiber and the fast response of the detectors, together with the two-color principle, permit high spatial and temporal resolution while allowing the user to dynamically alter the fiber-to-target distance.

  12. Double-clad hollow core photonic crystal fiber for coherent Raman endoscope.

    Science.gov (United States)

    Brustlein, Sophie; Berto, Pascal; Hostein, Richard; Ferrand, Patrick; Billaudeau, Cyrille; Marguet, Didier; Muir, Alistair; Knight, Jonathan; Rigneault, Hervé

    2011-06-20

    Performing label free coherent anti-Stokes Raman scattering (CARS) and stimulated Raman scattering (SRS) in endoscope imaging is a challenge, with huge potential clinical benefit. To date, this goal has remained inaccessible because of the inherent coherent Raman noise that is generated in the fiber itself. By developing double-clad hollow core photonic crystal fiber, we demonstrate coherent anti-Stokes Raman scattering and stimulated Raman scattering in an 'endoscope-like' scheme. Both the excitation beams and the collected CARS and SRS signals travel through the same fiber. No CARS and SRS signals are generated within the hollow core fiber even for temporally overlapping pump and Stokes beams, leading to excellent image quality. The CARS and SRS signals generated in the sample are coupled back into a high numerical aperture multimode cladding surrounding the central photonic crystal cladding. We demonstrate this scheme by imaging molecular vibrational bonds of organic crystal deposited on a glass surface.

  13. Tunable mid-infrared emission from acetylene-filled hollow-core fiber

    Science.gov (United States)

    Wang, Zefeng; Zhou, Zhiyue; Li, Zhixian; Zhang, Naiqian; Chen, Yubin

    2016-11-01

    We report here a step tunable mid-infrared laser emission from acetylene-filled hollow-core fiber. Two kinds of anti-resonant hollow-core fibers are filled with mbar level of acetylene gas, and pumped with a modulated, amplified, narrow linewidth, fine tunable, 1.5 μm diode laser, then 3 μm laser emissions are generated by the intrinsic absorption of acetylene molecules. The laser wavelength is step-tunable in the range of 3.1 3.2 μm when the pump laser is precisely tuned to different absorption lines of P-branch of acetylene. By properly designing the fiber's transmission bands, and carefully selecting active gases and pump lasers, this paper provides a novel method for efficient, compact and tunable mid-infrared fiber lasers over a broad spectrum range.

  14. Nonlinear optics at the single-photon level inside a hollow core fiber

    DEFF Research Database (Denmark)

    Hofferberth, Sebastian; Peyronel, Thibault; Liang, Qiyu

    2011-01-01

    Cold atoms inside a hollow core fiber provide an unique system for studying optical nonlinearities at the few-photon level. Confinement of both atoms and photons inside the fiber core to a diameter of just a few wavelengths results in high electric field intensity per photon and large optical...... depths with a relatively small number of atoms. We present our experimental apparatus and discuss results regarding all-optical switching at ultra-low light levels....

  15. Preparation of Composite Charge-mosaic Hollow Fiber Membrane by Interfacial Polymerization

    Institute of Scientific and Technical Information of China (English)

    Hao Qin ZHANG; Jin Dun LIU

    2004-01-01

    The preparation of composite charge-mosaic membrane included spinning of hollow fiber as the supporting membrane, preparing a selective layer on the inside surface of the fiber by interfacial polymerization. The charge-mosaic membranes show a high salt permeability while retaining sucrose. The charge-mosaic membrane can be effectively used to separate multivalent salts with organic matter of molecular weight great than 300 g/mol in industry.

  16. Silica hollow core microstructured fibers for beam delivery in industrial and medical applications

    Science.gov (United States)

    Shephard, Jonathan; Urich, Artur; Carter, Richard; Jaworski, Piotr; Maier, Robert; Belardi, Walter; Yu, Fei; Wadsworth, William; Knight, Jonathan; Hand, Duncan

    2015-04-01

    The focus of this review is our recent work to develop microstructured hollow core fibers for two applications where the flexible delivery of a single mode beam is desired. Also, a review of other fiber based solutions is included. High power, short-pulsed lasers are widely used for micro-machining, providing high precision and high quality. However, the lack of truly flexible beam delivery systems limits their application to the processing of relatively small planar components. To address this, we developed hollow-core optical fibers for the 1 μm and green wavelength ranges. The hollow core overcomes the power delivery limitations of conventional silica fibers arising from nonlinear effects and material damage in the solid core. We have characterized such fibers in terms of power handling capability, damage threshold, bend loss and dispersion, and practically demonstrated delivery of high peak power pulses from the nanosecond to the femtosecond regime. Such fibers are ideal candidates for industrial laser machining applications. In laser surgical applications, meanwhile, an Er:YAG laser (2.94 μm) is frequently the laser of choice because the water contained in tissue strongly absorbs this wavelength. If this laser beam is precisely delivered damage to surrounding tissue can be minimized. A common delivery method of surgical lasers, for use in the operating theatre, is articulated arms that are bulky, cumbersome and unsuitable for endoscopic procedures. To address this need for flexible mid-IR delivery we developed silica based hollow core fibers. By minimizing the overlap of the light with glass it is possible to overcome the material absorption limits of silica and achieve low attenuation. Additionally, it is possible to deliver pulse energies suitable for the ablation of both hard and soft tissue even with very small bend radii. The flexibility and small physical size of systems based on these fibers will enable new minimally invasive surgical procedures.

  17. Efficient optimization of hollow-core photonic crystal fiber design using the finite-element method

    DEFF Research Database (Denmark)

    Holzlöhner, Ronald; Burger, Sven; Roberts, John;

    2006-01-01

    We employ a finite-element (FE) solver with adaptive grid refinement to model hollow-core photonic crystal fibers (HC-PCFs) whose core is formed from 19 omitted cladding unit cells. We optimize the complete fiber geometry for minimal field intensity at material/air interfaces, which indicates low...... loss and high damage threshold, using multidimensional optimization. The optimal design shows a 99.8 % power fraction within the air and an overlap with a Gaussian mode of 96.9 %....

  18. Molecularly Designed Stabilized Asymmetric Hollow Fiber Membranes for Aggressive Natural Gas Separation.

    Science.gov (United States)

    Liu, Gongping; Li, Nanwen; Miller, Stephen J; Kim, Danny; Yi, Shouliang; Labreche, Ying; Koros, William J

    2016-10-24

    New rigid polyimides with bulky CF3 groups were synthesized and engineered into high-performance hollow fiber membranes. The enhanced rotational barrier provided by properly positioned CF3 side groups prohibited fiber transition layer collapse during cross-linking, thereby greatly improving CO2 /CH4 separation performance compared to conventional materials for aggressive natural gas feeds. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Silica hollow core microstructured fibers for beam delivery in industrial and medical applications

    Directory of Open Access Journals (Sweden)

    Jonathan Dale Shephard

    2015-04-01

    Full Text Available The focus of this review is our recent work to develop microstructured hollow core fibers for two applications where the flexible delivery of a single mode beam is desired. Also, a review of other fiber based solutions is included.High power, short-pulsed lasers are widely used for micro-machining, providing high precision and high quality. However, the lack of truly flexible beam delivery systems limits their application to the processing of relatively small planar components. To address this, we developed hollow-core optical fibers for the 1 μm and green wavelength ranges. The hollow core overcomes the power delivery limitations of conventional silica fibers arising from nonlinear effects and material damage in the solid core. We have characterized such fibers in terms of power handling capability, damage threshold, bend loss and dispersion, and practically demonstrated delivery of high peak power pulses from the nanosecond to the femtosecond regime. Such fibers are ideal candidates for industrial laser machining applications.In laser surgical applications, meanwhile, an Er:YAG laser (2.94 μm is frequently the laser of choice because the water contained in tissue strongly absorbs this wavelength. If this laser beam is precisely delivered damage to surrounding tissue can be minimized. A common delivery method of surgical lasers, for use in the operating theatre, is articulated arms that are bulky, cumbersome and unsuitable for endoscopic procedures. To address this need for flexible mid-IR delivery we developed silica based hollow core fibers. By minimizing the overlap of the light with glass it is possible to overcome the material absorption limits of silica and achieve low attenuation. Additionally, it is possible to deliver pulse energies suitable for the ablation of both hard and soft tissue even with very small bend radii. The flexibility and small physical size of systems based on these fibers will enable new minimally invasive surgical

  20. Humidity control during bell pepper storage, using a hollow fiber membrane contractor system

    NARCIS (Netherlands)

    Dijkink, B.H.; Tomassen, M.M.M.; Willemsen, J.H.A.; Doorn, van W.G.

    2004-01-01

    Green bell peppers (Capsicum annuum cv. Cardio) were stored in open crates at 5 degreesC, using a novel system for maintenance of relative humidity (RH). A hollow fiber membrane contactor allowed adequate transfer of water vapor between the air in the storage room and a liquid desiccant. The membran

  1. Composite hollow fiber membranes for organic solvent-based liquid-liquid extraction

    NARCIS (Netherlands)

    He, T.; Bolhuis-Versteeg, Lydia A.M.; Mulder, M.H.V.; Wessling, Matthias

    2004-01-01

    Instability issues of liquid membranes extraction significantly limit its wide application in industry. We report research on the application of a new composite hollow fiber membrane to stabilizing liquid membrane extraction. These type of composite membranes have either a polysulfone (PSf) ultrafil

  2. Antitumour efficacy of Piper tuberculatum and piplartine based on the hollow fiber assay.

    Science.gov (United States)

    Bezerra, Daniel P; Ferreira, Paulo Michel P; Machado, Camila Maria L; de Aquino, Nayara C; Silveira, Edilberto R; Chammas, Roger; Pessoa, Claudia

    2015-01-01

    Piper tuberculatum, popularly known in Brazil as "jaborandi falso" and "pimenta darta", is widely used in folk medicine for the treatment of several diseases. In this study, the in vivo hollow fiber assay was used to investigate the antitumour efficacy of the crude extract and piplartine obtained from P. tuberculatum roots. Human glioblastoma (SF-295) and colon carcinoma (HCT-8) cell lines were used. In vitro cytotoxicity was assayed by the MTT assay. In the hollow fiber assay, nude mice implanted with tumour cells in hollow fibers were treated for four consecutive days via the intraperitoneal route, and tumour cell populations were assessed by the MTT assay. Both the crude extract and piplartine displayed cytotoxicity. In the hollow fiber assay, tumour growth inhibition rates were 24.6-54.8 % for the crude extract and 33.7-62.2 % for piplartine. No signal of toxicity was noticed. In conclusion, the crude extract and piplartine obtained from P. tuberculatum roots displayed in vitro and in vivo anticancer efficacy.

  3. Modal dynamics in hollow-core photonic-crystal fibers with elliptical veins.

    Science.gov (United States)

    Hochman, Amit; Leviatan, Yehuda

    2005-08-08

    Modal characteristics of hollow-core photonic-crystal fibers with elliptical veins are studied by use of a recently proposed numerical method. The dynamic behavior of bandgap guided modes, as the wavelength and aspect ratio are varied, is shown to include zero-crossings of the birefringence, polarization dependent radiation losses, and deformation of the fundamental mode.

  4. Experimental investigation of hollow-core photonic crystal fibers with five photonic band-gaps

    Institute of Scientific and Technical Information of China (English)

    YUAN Jin-hui; HOU Lan-tian; WEI Dong-bin; WANG Hai-yun; ZHOU Gui-yao

    2008-01-01

    The hollow-core photonic crystal fibers (HC-PCFs) with integrity structure have been fabricated with an improved twice stack-and-draw technique. The transmission spectrum shows that five photonic band-gaps within 450-1100 nm have been obtained.And the green light transmission in the HC-PCFs'has been observed remarkably.

  5. Slow-light enhanced absorption in a hollow-core fiber

    DEFF Research Database (Denmark)

    Grgic, Jure; Xiao, Sanshui; Mørk, Jesper;

    2010-01-01

    Light traversing a hollow-core photonic band-gap fiber may experience multiple reflections and thereby a slow-down and enhanced optical path length. This offers a technologically interesting way of increasing the optical absorption of an otherwise weakly absorbing material which can infiltrate...

  6. Humidity control during bell pepper storage, using a hollow fiber membrane contractor system

    NARCIS (Netherlands)

    Dijkink, B.H.; Tomassen, M.M.M.; Willemsen, J.H.A.; Doorn, van W.G.

    2004-01-01

    Green bell peppers (Capsicum annuum cv. Cardio) were stored in open crates at 5 degreesC, using a novel system for maintenance of relative humidity (RH). A hollow fiber membrane contactor allowed adequate transfer of water vapor between the air in the storage room and a liquid desiccant. The membran

  7. Linear and nonlinear modeling of light propagation in hollow-core photonic crystal fiber

    DEFF Research Database (Denmark)

    Roberts, John; Lægsgaard, Jesper

    2009-01-01

    Hollow core photonic crystal fibers (HC-PCFs) find applications which include quantum and non-linear optics, gas detection and short high-intensity laser pulse delivery. Central to most applications is an understanding of the linear and nonlinear optical properties. These require careful modeling...

  8. Enzymatic conversion in ion-exchange mixed matrix hollow fiber membranes

    NARCIS (Netherlands)

    Andre, Joao; Borneman, Zandrie; Wessling, Matthias

    2013-01-01

    This work reports the adsorption of glucose oxidase (GOx) in particle-loaded hollow fibers using polyethersulfone as the matrix and Lewatit strong cation-exchange resins as the functional support. The activity of adsorbed GOx was evaluated under the same pH conditions as the adsorption. Static

  9. An Experiment to Introduce Mass Transfer Concepts Using a Commercial Hollow Fiber Blood Oxygenator

    Science.gov (United States)

    McIver, Keith; Merrill, Thomas; Farrell, Stephanie

    2017-01-01

    A commercial hollow fiber blood oxygenation laboratory experiment was used to introduce lower level engineering students to mass balances in a two-phase system. Using measured values of concentration and flow rate, students calculated the rate of mass transfer from the gas phase and into the liquid phase, and compared the two values to determine…

  10. Development and characterization of poly(ε-caprolactone) hollow fiber membranes for vascular tissue engineering

    NARCIS (Netherlands)

    Diban-Ibrahim Gomez, Nazely; Haimi, Suvi; Bolhuis-Versteeg, Lydia A.M.; Da Silva Teixeira, Sandra; Miettinen, S.; Poot, Andreas A.; Grijpma, Dirk W.; Stamatialis, Dimitrios

    2013-01-01

    The fabrication of tissue-engineered scaffolds for small-caliber blood vessels still remains a challenge. In the present work, we prepared poly(ε-caprolactone) (PCL) hollow fiber (HF) membranes, suitable for small-diameter blood vessel regeneration, by a phase separation spinning technique. The diff

  11. Low Loss and Highly Birefringent Hollow-Core Photonic Crystal Fiber

    DEFF Research Database (Denmark)

    Roberts, P. John; Williams, D.P.; Mangan, Brian J.;

    2006-01-01

    A hollow-core photonic crystal fiber design is proposed which enables both low-loss and polarization-maintained signal propagation. The design relies on an arrangement of antiresonant features positioned on the glass ring that surrounds the air core....

  12. Membrane distillation with porous metal hollow fibers for the concentration of thermo-sensitive solutions

    NARCIS (Netherlands)

    Shukla, S.

    2014-01-01

    This thesis presents an original approach for the concentration of thermo-sensitive solutions: the Sweep Gas Membrane Distillation (SGMD) process. A new membrane contactor with metallic hollow fibers has been designed and allows the distillation process to be operational at low temperature. Heat is

  13. "Chemistry in a spinneret" to fabricate hollow fibers for organic solvent filtration

    NARCIS (Netherlands)

    Dutczak, S.M.; Tanardi, Cheryl; Kopec, K.K.; Wessling, Matthias; Stamatialis, Dimitrios

    2012-01-01

    Organic solvent filtration (OSF) is a very efficient separation technique with high potential in many branches of industry. Currently the choice of the commercial membranes is limited only to a few flat sheet membranes and spiral wound modules. It is generally known that a membrane in hollow fiber

  14. Compression of realistic laser pulses in hollow-core photonic bandgap fibers

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Roberts, John

    2009-01-01

    Dispersive compression of chirped few-picosecond pulses at the microjoule level in a hollow-core photonic bandgap fiber is studied numerically. The performance of ideal parabolic input pulses is compared to pulses from a narrowband picosecond oscillator broadened by self-phase modulation during...

  15. Improvement of transmission properties for a rugged polymer-coated silver hollow fiber

    Science.gov (United States)

    Iwai, Katsumasa; Takaku, Hiroyuki; Miyagi, Mitsunobu; Shi, Yi-Wei; Matsuura, Yuji

    2015-03-01

    An extremely rugged hollow fiber is fabricated by liquid-phase coating technique. A silica glass capillary is used as the substrate and vitreous film is firstly coated on the inner surface of the capillary to protect the glass tube from moisture. This protective coating keeps the thin-wall glass tube away from damage due to the following silver plating process. The additional transmission loss caused by the roughness of the protective film is decreased by limiting the length of the protective film. The whole length of 0.7-mm-bore hollow fiber was 1.2 m and the length of the rugged part which formed the protective film was only 30 cm. Transmission properties of the rugged polymer-coated silver hollow fibers for the Er:YAG laser and red pilot beam delivery have been improved. The loss for the 0.7-μm-bore size, 1.2-m-length rugged polymer-coated silver hollow fiber was 1 dB and 6.9 dB under straight condition, and 1.9 dB and 9.4 dB under the condition of a 270 degree bend with a 15-mm bending radius at the wavelength of 2.94 μm and 650 nm, respectively.

  16. Polymeric hollow fiber membranes for bioartificial organs and tissue engineering applications

    NARCIS (Netherlands)

    Diban Ibrahim Gomez, N.; Stamatialis, D.

    2014-01-01

    Polymeric hollow fiber (HF) membranes are commercially available, i.e. microfiltration and ultrafiltration cartridges or reverse osmosis and gas separation modules, to be applied for separation purposes in industry, for instance to recover valuable raw materials or products, or for the treatment of

  17. Low Loss and Highly Birefringent Hollow-Core Photonic Crystal Fiber

    OpenAIRE

    2006-01-01

    A hollow-core photonic crystal fiber design is proposed which enables both low-loss and polarization-maintained signal propagation. The design relies on an arrangement of antiresonant features positioned on the glass ring that surrounds the air core.

  18. Preparation and characterization of gas separation hollow fiber membranes based on polyethersulfone-polyimide miscible blends

    NARCIS (Netherlands)

    Kapantaidakis, G.C.; Koops, G.H.; Wessling, M.

    2002-01-01

    In this work the preparation and characterization of gas separation hollow fibers based on polyethersulfone Sumikaexcel (PES) and polyimide Matrimid 5218 (PI) blends are reported. Scanning Electron Microscopy (SEM) was used to investigate the morphological characteristics and structure of the asymme

  19. Porous stainless steel hollow fibers with shrinkage-controlled small radial dimensions

    NARCIS (Netherlands)

    Luiten-Olieman, Mieke W.J.; Raaijmakers, Michiel J.T.; Winnubst, Louis; Wessling, Matthias; Nijmeijer, Arian; Benes, Nieck E.

    2011-01-01

    A method is presented for the preparation of thin (∼250 μm) porous stainless steel hollow fiber membranes based on dry–wet spinning of a particle-loaded polymer solution followed by heat treatment. Extraordinarily small radial dimensions were achieved by controlled shrinkage during thermal treatment

  20. Generation of high energy, 30 fs pulses at 527 nm by hollow-fiber compression technique.

    Science.gov (United States)

    Xia, J; Altucci, C; Amoruso, S; Bruzzese, R; Velotta, R; Wang, X

    2008-03-17

    The compression of 300-fs-long, chirp-free laser pulses at 527 nm down to 30 fs is reported. The laser pulses, originated from a frequency-doubled, mode-locked Nd:glass laser, were compressed by a 0.7-m-long, 150-microm-bore-diameter, argon-filled hollow fiber, and a pair of SF10 prisms with a final energy of 160 microJ. These are the shortest, high energy pulses ever produced by direct pulse compression at the central wavelength of 527 nm. The spectral broadening of the pulses propagating inside the hollow fiber was experimentally examined for various filling-gas pressures and input pulse energies. The spectral width of the pulses was broadened up to 25 nm, and 27 nm for argon- and krypton-filled hollow fiber, respectively, at a gas pressure lower than 2 bar. The physical limitations of the hollow-fiber pulse compression technique applied in the visible range are also studied.

  1. Transmission properties of hollow-core photonic bandgap fibers in relation to molecular spectroscopy

    DEFF Research Database (Denmark)

    Falk, Charlotte Ijeoma; Hald, Jan; Petersen, Jan C.;

    2010-01-01

    The transmission properties of five types of hollow-core photonic bandgap fibers (HC-PBFs) are characterized in the telecom wavelength range around 1:5 μm. The variations in optical transmission are measured as a function of laser frequency over a 2GHz scan range as well as a function of time over...

  2. Particle-loaded hollow-fiber membrane adsorbers for lysozyme separation

    NARCIS (Netherlands)

    Avramescu, M.E.; Borneman, Zandrie; Wessling, Matthias

    2008-01-01

    The separation of lysozyme (LZ), a valuable enzyme naturally present in chicken egg white, was carried out using a new type of ion exchange hollow-fiber membranes. Functionalities were incorporated into the polymeric membranes by dispersing ion-exchange resins (IERs) in a microporous structure

  3. Characterization of hollow fiber hemo-dialysis membranes: pore size distribution and performance

    NARCIS (Netherlands)

    Broek, A.P.; Broek, Arnold P.; Teunis, Herman A.; Teunis, Hermannus A.; Bargeman, D.; Bargeman, Derk; Sprengers, Erik D.; Smolders, C.A.; Smolders, C.A.

    1992-01-01

    The effect of two commonly used sterilization methods for artificial kidneys on the morphology and performance of hollow fiber Hemophan® hemodialysis membranes was studied. A relatively new membrane characterization method, thermoporometry, was used to determine the pore size distributions and

  4. Light source design using Kagome-lattice hollow core photonic crystal fibers

    Science.gov (United States)

    Hossain, Md. Anwar; Namihira, Yoshinori

    2014-09-01

    Supercontinuum (SC) light source is designed using high pressure Xe-filled hollow core Kagome-lattice photonic crystal fiber. Using finite element method with perfectly matched layer, SC spectra in normal chromatic dispersion region have been generated using picosecond optical pulses from relatively less expensive laser sources.

  5. Composite hollow fiber membranes for organic solvent-based liquid-liquid extraction

    NARCIS (Netherlands)

    He, T.; Versteeg, L.A.M.; Mulder, M.H.V.; Wessling, M.

    2004-01-01

    Instability issues of liquid membranes extraction significantly limit its wide application in industry. We report research on the application of a new composite hollow fiber membrane to stabilizing liquid membrane extraction. These type of composite membranes have either a polysulfone (PSf) ultrafil

  6. Low Bending Loss Nodeless Hollow-core Anti-Resonant Fiber

    CERN Document Server

    Gao, Shoufei; Liu, Xiaolu; Wang, Pu

    2016-01-01

    We report a high performance nodeless hollow-core anti-resonant fiber with a broadband guidance from 1050 nm to >1900 nm, a transmission attenuation of 200 dB/km, and a low bending loss of 0.25 dB/m for a 5 cm radius at wavelength of 1550 nm.

  7. Efficient all-optical switching using slow light within a hollow fiber

    DEFF Research Database (Denmark)

    Bajcsy, Michal; Hofferberth, S.; Balic, Vlatko

    2009-01-01

    We demonstrate a fiber-optical switch that is activated at tiny energies corresponding to a few hundred optical photons per pulse. This is achieved by simultaneously confining both photons and a small laser-cooled ensemble of atoms inside the microscopic hollow core of a single-mode photonic...

  8. Dehydration of Ethanol-Water Mixture by Pervaporation using Poly(amide-imide) Hollow Fiber Membrane

    National Research Council Canada - National Science Library

    Shinsuke TAKEGAMI; TUJII, Hideki YAMADA

    1993-01-01

    ..... The heat treament at 265 °C gives a high separation factor of water to ethanol. The module having a membrane surface of 1 m2 was prepared by binding the hollow fibers of 3000pieces and potting in potting resin...

  9. Mixed matrix hollow fiber membranes for removal of protein-bound toxins from human plasma

    NARCIS (Netherlands)

    Tijink, M.S.L.; Wester, M.; Glorieux, G.; Gerritsen, K; Sun, J.; Swart, P.C.; Borneman, Z.; Wessling, M.; Vanholder, R.; Joles, J.A.; Stamatialis, D.

    2013-01-01

    In end stage renal disease (ESRD) waste solutes accumulate in body fluid. Removal of protein bound solutes using conventional renal replacement therapies is currently very poor while their accumulation is associated with adverse outcomes in ESRD. Here we investigate the application of a hollow fiber

  10. Characterization of polyethersulfone-polyimide hollow fiber membranes by atomic force microscopy and contact angle goniometery

    NARCIS (Netherlands)

    Khulbe, K.C.; Feng, C.; Matsuura, T.; Kapantaidakis, G.; Wessling, Matthias; Koops, G.H.

    2003-01-01

    Asymmetric blend polyethersulfone-polyimide (PES-PI) hollow fiber membranes prepared at different air gap and used for gas separation are characterized by atomic force microscopy (inside and out side surfaces) and by measuring the contact angle of out side surface. The outer surface was entirely

  11. Hollow-core infrared fiber incorporating metal-wire metamaterial

    DEFF Research Database (Denmark)

    Yan, Min; Mortensen, Asger

    2009-01-01

    Infrared (IR) light is considered important for short-range wireless communication, thermal sensing, spectroscopy, material processing, medical surgery, astronomy etc. However, IR light is in general much harder to transport than optical light or microwave radiation. Existing hollow-core IR...

  12. Hollow core fiber optics for mid-wave and long-wave infrared spectroscopy

    Science.gov (United States)

    Kriesel, Jason M.; Gat, Nahum; Bernacki, Bruce E.; Erikson, Rebecca L.; Cannon, Bret D.; Myers, Tanya L.; Bledt, Carlos M.; Harrington, James A.

    2011-05-01

    We describe the development and testing of hollow core glass waveguides (i.e., fiber optics) for use in Mid-Wave Infrared (MWIR) and Long-Wave Infrared (LWIR) spectroscopy systems. Spectroscopy measurements in these wavelength regions (i.e., from 3 to 14 μm) are useful for detecting trace chemical compounds for a variety of security and defense related applications, and fiber optics are a key enabling technology needed to improve the utility and effectiveness of detection and calibration systems. Hollow glass fibers have the advantage over solid-core fibers (e.g., chalcogenide) in that they are less fragile, do not produce cladding modes, do not require angle cleaving or antireflection coatings to minimize laser feedback effects, and effectively transmit deeper into the infrared. This paper focuses on recent developments in hollow fiber technology geared specifically for infrared spectroscopy, including single mode beam delivery with relatively low bending loss. Results are presented from tests conducted using both Quantum Cascade Lasers (QCL) and CO2 lasers operating in the LWIR wavelength regime. Single-mode waveguides are shown to effectively deliver beams with relatively low loss (~ 1 dB/m) and relatively high beam quality. The fibers are also shown to effectively mode-filter the "raw" multi-mode output from a QCL, in effect damping out the higher order modes to produce a circularly symmetric Gaussian-like beam profile.

  13. Influence of chemical agents on the surface area and porosity of active carbon hollow fibers

    Directory of Open Access Journals (Sweden)

    LJILJANA M. KLJAJEVIĆ

    2011-09-01

    Full Text Available Active carbon hollow fibers were prepared from regenerated polysulfone hollow fibers by chemical activation using: disodium hydrogen phosphate 2-hydrate, disodium tetraborate 10-hydrate, hydrogen peroxide, and diammonium hydrogen phosphate. After chemical activation fibers were carbonized in an inert atmosphere. The specific surface area and porosity of obtained carbons were studied by nitrogen adsorption–desorption isotherms at 77 K, while the structures were examined with scanning electron microscopy and X-ray diffraction. The activation process increases these adsorption properties of fibers being more pronounced for active carbon fibers obtained with disodium tetraborate 10-hydrate and hydrogen peroxide as activator. The obtained active hollow carbons are microporous with different pore size distribution. Chemical activation with phosphates produces active carbon material with small surface area but with both mesopores and micropores. X-ray diffraction shows that besides turbostratic structure typical for carbon materials, there are some peaks which indicate some intermediate reaction products when sodium salts were used as activating agent. Based on data from the electrochemical measurements the activity and porosity of the active fibers depend strongly on the oxidizing agent applied.

  14. Novel concept for pure diffusive capillary membrane oxygenators: silicone hollow sphere (SiHSp) fibers.

    Science.gov (United States)

    Khachab, Ali; Tabesh, Hadi; Kashefi, Ali; Mottaghy, Khosrow

    2013-01-01

    The preeminent limitation of silicone membrane oxygenators is the poor gas permeability compared with microporous hollow fiber oxygenators (MHFO). However, the imponderability of plasma leakage, foam formation, and brittleness are all hazards that result in blood trauma formation, hereby limiting the application of MHFO during long-term oxygenation therapies. Here, we introduce a novel type of pure diffusive capillary-form silicone membrane called silicone hollow sphere. Silicone hollow sphere walls embed hollow microspheres into the core. The lodging of such microspheres promotes a higher gas exchange performance (as a result of the reduction of dense material) without altering the total thickness of capillary walls; thereby the demanded mechanical strength for handling is nevertheless conserved. Out of the same silicone material, seven SiHSp fibers with six different design specifications and a control were constructed to define experimentally the appropriate configuration for subsequent production. Each fiber was used in a miniaturized module oxygenator of a constant effective membrane surface area (Amem = 0.02 m) and length (L =183 mm) for a fair evaluation. Modules were investigated in vitro with porcine blood. O2 and CO2 transfer rates weighed 12.6 mlO2/min and 10.4 mlCO2/min, respectively, for one type of SiHSp, comparable with microporous polypropylene (OXYPHAN) exhibiting 14.1 mlO2/min and 13.2 mlCO2/min, respectively, at a maximum blood flow rate (Qmax = 200 ml/min). Silicone hollow sphere fibers show a promising competency to MHFs. They also show an evident dominancy over the conventional silicone fibers, evaluated by the control module, which emphasizes the advantage of this design.

  15. Thermally moderated hollow fiber sorbent modules in rapidly cycled pressure swing adsorption mode for hydrogen purification

    KAUST Repository

    Lively, Ryan P.

    2012-10-01

    We describe thermally moderated multi-layered pseudo-monolithic hollow fiber sorbents entities, which can be packed into compact modules to provide small-footprint, efficient H2 purification/CO2 removal systems for use in on-site steam methane reformer product gas separations. Dual-layer hollow fibers are created via dry-jet, wet-quench spinning with an inner "active" core of cellulose acetate (porous binder) and zeolite NaY (69 wt% zeolite NaY) and an external sheath layer of pure cellulose acetate. The co-spun sheath layer reduces the surface porosity of the fiber and was used as a smooth coating surface for a poly(vinyl-alcohol) post-treatment, which reduced the gas permeance through the fiber sorbent by at least 7 orders of magnitude, essentially creating an impermeable sheath layer. The interstitial volume between the individual fibers was filled with a thermally-moderating paraffin wax. CO2 breakthrough experiments on the hollow fiber sorbent modules with and without paraffin wax revealed that the "passively" cooled paraffin wax module had 12.5% longer breakthrough times than the "non-isothermal" module. The latent heat of fusion/melting of the wax offsets the released latent heat of sorption/desorption of the zeolites. One-hundred rapidly cycled pressure swing adsorption cycles were performed on the "passively" cooled hollow fiber sorbents using 25 vol% CO2/75 vol% He (H2 surrogate) at 60 °C and 113 psia, resulting in a product purity of 99.2% and a product recovery of 88.1% thus achieving process conditions and product quality comparable to conventional pellet processes. Isothermal and non-isothermal dynamic modeling of the hollow fiber sorbent module and a traditional packed bed using gPROMS® indicated that the fiber sorbents have sharper fronts (232% sharper) and longer adsorbate breakthrough times (66% longer), further confirming the applicability of the new fiber sorbent approach for H2 purification. © 2012, Hydrogen Energy Publications, LLC

  16. Modeling of hydrodynamics in hollow fiber membrane bioreactor for mammalian cells cultivation

    Directory of Open Access Journals (Sweden)

    N. V. Menshutina

    2016-01-01

    Full Text Available The mathematical modelling in CFD-packages are powerfull instrument for design and calculation of any engineering tasks. CFD-package contains the set of programs that allow to model the different objects behavior based on the mathematical lows. ANSYS Fluent are widely used for modelling of biotechnological and chemical-technological processes. This package is convenient to describe their hydrodynamics. As cell cultivation is one of the actual scientific direction in modern biotechnology ANSYS Fluent was used to create the model of hollow fiber membrane bioreactor. The fibers are hollow cylindrical membrane to be used for cell cultivation. The criterion of process effectiveness for cell growth is full filling of the membrane surface by cells in the bioreactor. While the cell growth the fiber permeability is decreased which effects to feed flow through membrane pores. The specific feature of this process is to ensure such feed flow to deliver the optimal nutrition for the cells on the external membrane surface. The velocity distribution inside the fiber and in all bioreactor as a whole has been calculated based on mass an impulse conservation equations taking into account the mathematical model assumptions. The hydrodynamics analysis in hollow fiber membrane bioreactor is described by the three-dimensional model created in ANSYS Fluent. The specific features of one membrane model are considered and for whole bioreactor too.

  17. "The blood pressure and dermal sensitivity effects of Nylon hollow fiber releasing Glycerin Trinitrate in vivo "

    Directory of Open Access Journals (Sweden)

    "Ostad SN

    2002-09-01

    Full Text Available In order to improve patient's compliance in taking glycerine trinitrate (GTN nylon hollow fiber which has been successfully used for release of chlorhexidine diacetate and levonorgestrel was employed to make nylon hollow fiber releasing GTN. Hollow nylon fibres of external diameter 0.63 mm, 75 mm long with an internal capacity of 16 μl, were filled with GTN (190 mg/ml in 70% ethanol (v/v or vehicle alone and the ends were heat-sealed. The fibers were then immersed in 10 ml of 0.9% (w/v saline in a separating funnel. The GTN release pattern from fiber, the effect of the product on blood pressure and its potential dermal toxicity were assessed. The release of GTN from the fibres was approximately 2.7 μg/min when the fibres contained 16 mg of drug. The results showed that the amount of GTN within the single fibre was enough to reduce blood pressure significantly, while it did not show significant dermal toxicity. It is concluded that GTN fiber, if used as monofilament, is not an alternative method for GTN delivery.

  18. Hollow-fiber blood-dialysis membranes: superoxide generation, permeation, and dismutation measured by chemiluminescence.

    Science.gov (United States)

    Yamamoto, Ken-ichiro; Kobayashi, Kazuyoshi; Endo, Kosuke; Miyasaka, Takehiro; Mochizuki, Seiichi; Kohori, Fukashi; Sakai, Kiyotaka

    2005-01-01

    The interaction of blood with a material surface results in activation of the body's humoral immune system and the generation of reactive oxygen species (ROS). It has recently become clear that ROS are central to the pathology of many diseases. In this study, we evaluated the superoxide generation, permeation, and dismutation in hollow-fiber dialysis membranes by using 2-methyl-6-p-methoxyphenylethynyl-imidazopyrazinone (MPEC) as a superoxide-reactive chemiluminescence producer and an optical fiber probe to detect the resulting chemiluminescence in the hollow fiber lumen. We measured the superoxide generated when bovine blood leukocytes were brought into contact with dialysis membranes. Superoxide permeation was determined by measuring MPEC chemiluminescence in the hollow fiber lumen using an optical fiber probe. Additionally, superoxide dismutation was evaluated by examining the difference in superoxide permeability for membranes with and without vitamin E coating. Superoxide generation varies for different membrane materials, depending on the membrane's biocompatibility. Superoxide permeability depends on the diffusive permeability of membranes. No marked decrease in superoxide permeability was observed among membrane materials. The superoxide permeability of vitamin E-coated membrane was smaller than that of uncoated membrane. The antioxidant property of vitamin E-coated membranes is hence effective in causing superoxide dismutation.

  19. A validated CFD model to predict O₂ and CO₂ transfer within hollow fiber membrane oxygenators.

    Science.gov (United States)

    Hormes, Marcus; Borchardt, Ralf; Mager, Ilona; Rode, Thomas Schmitz; Behr, Marek; Steinseifer, Ulrich

    2011-03-01

    Hollow fiber oxygenators provide gas exchange to and from the blood during heart surgery or lung recovery. Minimal fiber surface area and optimal gas exchange rate may be achieved by optimization of hollow fiber shape and orientation (1). In this study, a modified CFD model is developed and validated with a specially developed micro membrane oxygenator (MicroMox). The MicroMox was designed in such a way that fiber arrangement and bundle geometry are highly reproducible and potential flow channeling is avoided, which is important for the validation. Its small size (V(Fluid)=0.04 mL) allows the simulation of the entire bundle of 120 fibers. A non-Newtonian blood model was used as simulation fluid. Physical solubility and chemical bond of O₂ and CO₂ in blood was represented by the numerical model. Constant oxygen partial pressure at the pores of the fibers and a steady state flow field was used to calculate the mass transport. In order to resolve the entire MicroMox fiber bundle, the mass transport was simulated for symmetric geometry sections in flow direction. In vitro validation was achieved by measurements of the gas transfer rates of the MicroMox. All measurements were performed according to DIN EN 12022 (2) using porcine blood. The numerical simulation of the mass transfer showed good agreement with the experimental data for different mass flows and constant inlet partial pressures. Good agreement could be achieved for two different fiber configurations. Thus, it was possible to establish a validated model for the prediction of gas exchange in hollow fiber oxygenators.

  20. Enhanced four-wave mixing in a hollow-core photonic-crystal fiber.

    Science.gov (United States)

    Konorov, S O; Fedotov, A B; Zheltikov, A M

    2003-08-15

    Hollow-core photonic-crystal fibers are shown to substantially enhance four-wave mixing (FWM) of laser pulses in a gas filling the fiber core. Picosecond pulses of Nd:YAG fundamental radiation and its second harmonic are used to generate a signal at the frequency of the third harmonic by the FWM process 3omega = 2omega + 2omega - omega. The efficiency achieved for this process in a 9-cm-long, 13-microm-hollow-core-diameter photonic-crystal fiber, designed to simultaneously transmit a two-color pump and the FWM signal, is shown to be approximately 800 times higher than the maximum FWM efficiency attainable with the same laser pulses in the tight-focusing regime.

  1. Dual membrane hollow fiber fuel cell and method of operating same

    Science.gov (United States)

    Ingham, J. D.; Lawson, D. D. (Inventor)

    1978-01-01

    A gaseous fuel cell is described which includes a pair of electrodes formed by open-ended, ion-exchange hollow fibers, each having a layer of metal catalyst deposited on the inner surface and large surface area current collectors such as braided metal mesh in contact with the metal catalyst layer. A fuel cell results when the electrodes are immersed in electrolytes and electrically connected. As hydrogen and oxygen flow through the bore of the fibers, oxidation and reduction reactions develop an electrical potential. Since the hollow fiber configuration provides large electrode area per unit volume and intimate contact between fuel and oxidizer at the interface, and due to the low internal resistance of the electrolyte, high power densities can be obtained.

  2. High capacitive performance of hollow activated carbon fibers derived from willow catkins

    Science.gov (United States)

    Wang, Kai; Song, Yan; Yan, Rui; Zhao, Ning; Tian, Xiaodong; Li, Xiao; Guo, Quangui; Liu, Zhanjun

    2017-02-01

    In this paper, we prepared three different kinds of hollow activated carbon fibers (HACFs) from willow catkins (WCs), phenolic- and pitch-based hollow fibers, respectively. The morphology, pore structure, surface chemical composition and electrochemical properties of these hollow fibers were studied in parallel. Due to its high-hollow, cost-effective as well as eco-friendly nature, HACFs derived from WCs can be served as excellent electrode materials for electrochemical energy storage devices. Electrochemical measurements illustrate that the WCs derived HACFs exhibit not only high specific capacitance of 333 F g-1 at 0.1 A g-1 but also considerable rate capability with a retention of 62.7% (209 F g-1 at 10 A g-1). Symmetric supercapacitor devices that using WCs derived HACFs as electrodes deliver a maximum energy density of ∼8.8 Wh kg-1 at power density of 50 W kg-1 and good cycling performance with 95.5% retention over 3000 cycles at 5 A g-1 in 6 M KOH aqueous electrolytes.

  3. Impact of core cladding boundary shape on the waveguide properties of hollow core microstructured fibers

    CERN Document Server

    Pryamikov, A D; Biriukov, A S

    2016-01-01

    In this paper we consider an interaction between the air core modes of hollow core waveguide microstructures and core cladding boundary walls in various shapes. The analysis is based on well established models such as the anti-resonant reflecting optical waveguide model and on the models proposed for the first time. In particular, we consider the dynamics of light localization in the polygonalcore cladding boundary wall as dependant on the type of its discrete rotational symmetry. Based on our findings we analyze the mechanisms of light localization in the core cladding boundary walls of negative curvature hollow core microstructured fibers.

  4. Impact of core-cladding boundary shape on the waveguide properties of hollow core microstructured fibers

    Science.gov (United States)

    Pryamikov, A. D.; Alagashev, G. K.; Kosolapov, A. F.; Biriukov, A. S.

    2016-12-01

    In this paper we consider an interaction between the air core modes (ACMs) of hollow core waveguide microstructures and core-cladding boundary walls in various shapes. The analysis is based on well-established models such as the ARROW (anti-resonant reflecting optical waveguide) model and on the models proposed for the first time. In particular, we consider the dynamics of light localization in the polygonal core cladding boundary wall as dependant on the type of its discrete rotational symmetry. Based on our findings we analyze the mechanisms of light localization in the core-cladding boundary walls of negative curvature hollow core microstructured fibers (NC HCMFs).

  5. All-Silica Hollow-Core Microstructured Bragg Fibers for Biosensor Application

    DEFF Research Database (Denmark)

    Passaro, Davide; Foroni, Matteo; Poli, Federica

    2008-01-01

    on the finite-element method. Since the DNA molecules necessary for the biosensor realization are in aqueous solution, it has been taken into account a microstructured fiber with water-filled holes. The dispersion curve and the confinement loss spectrum have been calculated in order to understand how a biofilm...... layer on the inner surface of the fiber holes can modify the fundamental mode properties. The numerical analysis results have successfully demonstrated the DNA bio-sensor feasibility in hollow-core Bragg fibers....

  6. Large-pitch kagome-structured hollow-core photonic crystal fiber

    Science.gov (United States)

    Couny, F.; Benabid, F.; Light, P. S.

    2006-12-01

    We report the fabrication and characterization of a new type of hollow-core photonic crystal fiber based on large-pitch (˜12μm) kagome lattice cladding. The optical characteristics of the 19-cell, 7-cell, and single-cell core defect fibers include broad optical transmission bands covering the visible and near-IR parts of the spectrum with relatively low loss and low chromatic dispersion, no detectable surface modes and high confinement of light in the core. Various applications of such a novel fiber are also discussed, including gas sensing, quantum optics, and high harmonic generation.

  7. Numerical analysis of plastic hollow core microstructured fiber for Terahertz applications

    Science.gov (United States)

    Vincetti, L.

    2009-08-01

    Propagation loss and dispersion characteristics of a hollow core microstructured fiber in the THz regime are numerically investigated. The fiber cladding consists of a triangular lattice formed by a periodic arrangement of dielectric tubes of Teflon. Numerical results show that guidance mechanism is the same of kagome and square lattice fibers. Low loss and low dispersion frequency ranges can be tuned just by changing the thickness of the tubes irrespectively of their diameter. Propagation loss four decades lower than the bulk absorption and dispersion lower 0.03 ps/nm km can be obtained over a band of about 1.7 THz centered at 2.1 THz.

  8. Cladding defects in hollow core fibers for surface mode suppression and improved birefringence

    DEFF Research Database (Denmark)

    Michieletto, Mattia; Lyngso, J. K.; Lægsgaard, Jesper;

    2014-01-01

    We demonstrate a novel polarization maintaining hollow-core photonic bandgap fiber geometry that reduces the impact of surface modes on fiber transmission. The cladding structure is modified with a row of partially collapsed holes to strip away unwanted surface modes. A theoretical investigation...... of the surface mode stripping is presented and compared to the measured performance of four 7-cells core fibers that were drawn with different collapse ratio of the defects. The varying pressure along the defect row in the cladding during drawing introduces an ellipticity of the core. This, combined...

  9. Laser-cooled atoms inside a hollow-core photonic-crystal fiber

    DEFF Research Database (Denmark)

    Bajcsy, Michal; Hofferberth, S.; Peyronel, Thibault

    2011-01-01

    We describe the loading of laser-cooled rubidium atoms into a single-mode hollow-core photonic-crystal fiber. Inside the fiber, the atoms are confined by a far-detuned optical trap and probed by a weak resonant beam. We describe different loading methods and compare their trade-offs in terms...... of implementation complexity and atom-loading efficiency. The most efficient procedure results in loading of ∼30,000 rubidium atoms, which creates a medium with an optical depth of ∼180 inside the fiber. Compared to our earlier study this represents a sixfold increase in the maximum achieved optical depth...

  10. Fouling behavior of microstructured hollow fiber membranes in submerged and aerated filtrations.

    Science.gov (United States)

    Culfaz, P Z; Wessling, M; Lammertink, R G H

    2011-02-01

    The performance of microstructured hollow fiber membranes in submerged and aerated systems was investigated using colloidal silica as a model foulant. The microstructured fibers were compared to round fibers and to twisted microstructured fibers in flux-stepping experiments. The fouling resistances in the structured fibers were found to be higher than those of round fibers. This was attributed to stagnant zones in the grooves of the structured fibers. As the bubble sizes were larger than the size of the grooves of the structured fibers, it is possible that neither the bubbles nor the secondary flow caused by the bubbles can reach the bottom parts of the grooves. Twisting the structured fibers around their axes resulted in decreased fouling resistances. Large, cap-shaped bubbles and slugs were found to be the most effective in fouling removal, while small bubbles of sizes similar to the convolutions in the structured fiber did not cause an improvement in these fibers. Modules in a vertical orientation performed better than horizontal modules when coarse bubbling was used. For small bubbles, the difference between vertical and horizontal modules was not significant. When the structured and twisted fibers were compared to round fibers with respect to the permeate flowrate produced per fiber length instead of the actual flux through the convoluted membrane area, they showed lower fouling resistance than round fibers. This is because the enhancement in surface area is more than the increase in resistance caused by stagnant zones in the grooves of the structured fibers. From a practical point of view, although the microstructure does not promote further turbulence in submerged and aerated systems, it can still be possible to enhance productivity per module with the microstructured fibers due to their high surface area-to-volume ratio.

  11. Ultem®/ZIF-8 mixed matrix hollow fiber membranes for CO2/N2 separations

    KAUST Repository

    Dai, Ying

    2012-05-01

    Organic-inorganic hybrid (mixed matrix) membranes can potentially extend the separation performance of traditional polymeric materials while maintaining processing convenience. Although many dense films studies have been reported, there have been few reported cases of these materials being successfully extended to asymmetric hollow fibers. In this work we report the first successful production of mixed matrix asymmetric hollow fiber membranes containing metal-organic-framework (MOF) ZIF-8 fillers. Specifically, we have incorporated ZIF-8 into a polyetherimide (Ultem ® 1000) matrix and produced dual-layer asymmetric hollow fiber membranes via the dry jet-wet quench method. The outer separating layer of these composite fibers contains 13wt% (17vol%) of ZIF-8 filler. These membranes have been tested over a range of temperatures and pressures for a variety of gas pairs. An increase in separation performance for the CO 2/N 2 gas pairs was observed for both pure gas and mixed gas feeds. © 2012 Elsevier B.V.

  12. Ultem((R))/ZIF-8 mixed matrix hollow fiber membranes for CO2/N-2 separations

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Y; Johnson, JR; Karvan, O; Sholl, DS; Koros, WJ

    2012-05-15

    Organic-inorganic hybrid (mixed matrix) membranes can potentially extend the separation performance of traditional polymeric materials while maintaining processing convenience. Although many dense films studies have been reported, there have been few reported cases of these materials being successfully extended to asymmetric hollow fibers. In this work we report the first successful production of mixed matrix asymmetric hollow fiber membranes containing metal-organic-framework (MOF) ZIF-8 fillers. Specifically, we have incorporated ZIF-8 into a polyetherimide (Ultem((R)) 1000) matrix and produced dual-layer asymmetric hollow fiber membranes via the dry jet-wet quench method. The outer separating layer of these composite fibers contains 13 wt% (17 vol%) of ZIF-8 filler. These membranes have been tested over a range of temperatures and pressures for a variety of gas pairs. An increase in separation performance for the CO2/N-2 gas pairs was observed for both pure gas and mixed gas feeds. (C) 2012 Elsevier B.V. All rights reserved.

  13. Guiding Properties of Silica/Air Hollow-Core Bragg Fibers

    DEFF Research Database (Denmark)

    Foroni, Matteo; Passaro, Davide; Poli, Federica

    2008-01-01

    The guiding properties of realistic silica/air hollow-core Bragg fibers have been investigated by calculating the dispersion curves, the confinement loss spectrum and the field distribution of the guided modes through a full-vector modal solver based on the finite element method. In particular, t...... the different possible applications, the feasibility of a DNA bio-sensor based on a hollow-core Bragg fiber has been demonstrated.......The guiding properties of realistic silica/air hollow-core Bragg fibers have been investigated by calculating the dispersion curves, the confinement loss spectrum and the field distribution of the guided modes through a full-vector modal solver based on the finite element method. In particular......, the silica bridge influence on the fundamental mode has been analyzed, by comparing the properties of an ideal structure, without the silica nano-supports, and of two realistic fibers, with squared off and rounded air-holes. Simulation results have demonstrated the presence of anti-crossing points...

  14. The evaluation of hollow-fiber ultrafiltration and celite concentration of enteroviruses, adenoviruses and bacteriophage from different water matrices

    Data.gov (United States)

    U.S. Environmental Protection Agency — The data to support the evaluation of hollow-fiber ultrafiltration and celite concentration of enteroviruses, adenoviruses and bacteriophage from different water...

  15. Plasticization-resistant hollow fiber membranes for CO2/CH4 separation based on a thermally crosslinkable polyimide

    KAUST Repository

    Chen, Chien-Chiang

    2011-10-01

    Decarboxylation-induced thermal crosslinking has been demonstrated to be effective for stabilizing membranes against plasticization in dense films. This study extends this promising crosslinking approach from dense films to industrially relevant asymmetric hollow fiber membranes. Crosslinkable asymmetric hollow fiber membranes were spun from a carboxylic acid containing polyimide, 6FDA-DAM:DABA. Dope and spinning conditions were optimized to obtain fibers with a defect-free selective skin layer. It is found that slightly defective fibers suffered severe selectivity loss after thermal crosslinking, suggesting that defect-free property is essential to the performance of the resulting crosslinked hollow fiber membranes. The crosslinked fibers were tested for CO 2/CH 4 separation. The excellent plasticization resistance under high pressure feeds (with highest CO 2 partial pressure of 400psia) suggests that these robust membranes are promising for aggressive natural gas purification. © 2011 Elsevier B.V.

  16. MORPHOLOGIES AND GAS SEPARATION PROPERTIES OF MELT-SPUN ASYMMETRIC POLY(4-METHYL-1-PENTENE) HOLLOW FIBER MEMBRANES

    Institute of Scientific and Technical Information of China (English)

    Jian-li Wang; Zhi-kang Xu; You-yi Xu

    2003-01-01

    Poly(4-methyl-1-pentene) (PMP) hollow fiber membranes were prepared by the melt-spun and cold-stretch(MSCS) method. Scanning electronic microscopy (SEM) was used to characterize the section and surface structures of the membranes with special asymmetric structure. The preliminary results of gas permeation measurements indicated that the resultant hollow fiber membranes have the potential ability for oxygen/nitrogen separation.

  17. THE ROLE OF POROUS MEDIA IN MODELING FLUID FLOW WITHIN HOLLOW FIBER MEMBRANES OF THE TOTAL ARTIFICIAL LUNG

    OpenAIRE

    2010-01-01

    A numerical study was conducted to analyze fluid flow within hollow fiber membranes of the artificial lungs. The hollow fiber bundle was approximated using a porous media model. In addition, the transport equations were solved using the finite-element formulation based on the Galerkin method of weighted residuals. Comparisons with previously published work on the basis of special cases were performed and found to be in excellent agreement. A Newtonian viscous fluid model for the blood was use...

  18. On-line extraction and determination of two herbicides: comparison between two modes of three-phase hollow fiber microextraction.

    Science.gov (United States)

    Tajik, Mohammad; Yamini, Yadollah; Esrafili, Ali; Ebrahimpour, Behnam

    2015-02-01

    Two different modes of three-phase hollow fiber liquid-phase microextraction were studied for the extraction of two herbicides, bensulfuron-methyl and linuron. In these two modes, the acceptor phases in the lumen of the hollow fiber were aqueous and organic solvents. The extraction and determination were performed using an automated hollow fiber microextraction instrument followed by high-performance liquid chromatography. For both three-phase hollow fiber liquid-phase microextraction modes, the effect of the main parameters on the extraction efficiency were investigated and optimized by central composite design. Under optimal conditions, both modes showed good linearity and repeatability, but the three-phase hollow fiber liquid-phase microextraction based on two immiscible organic solvents has a better extraction efficiency and figures of merit. The calibration curves for three-phase hollow fiber liquid-phase microextraction with an organic acceptor phase were linear in the range of 0.3-200 and 0.1-150 μg/L and the limits of detection were 0.1 and 0.06 μg/L for bensulfuron-methyl and linuron, respectively. For the conventional three-phase hollow fiber liquid-phase microextraction, the calibration curves were linear in the range of 3.0-250 and 15-400 μg/L and LODs were 1.0 and 5.0 μg/L for bensulfuron-methyl and linuron, respectively. The real sample analysis was carried out by three-phase hollow fiber liquid phase microextraction based on two immiscible organic solvents because of its more favorable characteristics.

  19. Hollow fiber-supported designer ionic liquid sponges for post-combustion CO2 scrubbing

    Energy Technology Data Exchange (ETDEWEB)

    Lee, JS; Hillesheim, PC; Huang, DK; Lively, RP; Oh, KH; Dai, S; Koros, WJ

    2012-11-30

    A proof of concept study for a new type of carbon capture system is considered for post-combustion CO2 capture based on porous hollow fiber sorbents with ionic liquids sorbed in the cell walls of the fiber. This study proves that delicate morphological features in the open-celled porous wall can be maintained during the infusion process. Mixtures of task specific ionic liquid (i.e. [BMIM][Tf2N]) and superbase (i.e. DBU) were loaded into polyamide-imide (PAI) fibers by a so-called two-step non-solvent infusion protocol. In the protocol, methanol carries ionic liquids into the pore cell walls of hollow fibers and then hexane carries superbase to create an efficient CO2 sorbent. Our ionic liquid/superbase impregnation technique overcomes a serious increase in mass transfer resistance upon reaction with CO2, thereby allowing its large scale utilization for post-combustion CO2 capture. The investigation on the effect of different pore former additives (different molecular weights of polyvinylpyrrolidone, lithium nitrate, and their mixtures) suggested that a large molecular weight of PVP (M-w; 1300k) including dope composition produces highly interconnected open cell pore structures of PAI hollow fibers. Lastly, a lumen side barrier layer was successfully formed on the bore side of neat PAI fibers by using a mixture of Neoprene (R) with crosslinking agents (TSR-633) via a post-treatment process. The lumen layer will enable heat removal from the fiber sorbents during their application in rapid thermal swing cycling processes. (C) 2012 Elsevier Ltd. All rights reserved.

  20. Delivery of F2-excimer laser light by aluminum hollow fibers.

    Science.gov (United States)

    Matsuura, Y; Yamamoto, T; Miyagi, M

    2000-06-19

    A hollow fiber composed of a glass-tube substrate and an aluminum thin film coated upon the inside of the tube delivers F2-excimer laser light. A smooth, aluminum thin film was deposited by using metal-organic chemical vapor deposition using dimethylethylamine:alane (DMEAA) as the precursor. It was shown that the transmission loss of the fiber with a 1.0-mm inner diameter was as low as 0.5 dB/m for the fiber with 1.0-mm diameter when the bore of the fiber is pressurized with an inert gas to remove the absorption of air. When the fiber is bent at the radius of 30 cm, the additional loss was 1.6 dB.

  1. Antiresonant guiding in a poly(methyl-methacrylate) hollow-core optical fiber

    DEFF Research Database (Denmark)

    Markos, Christos; Nielsen, Kristian; Bang, Ole

    2015-01-01

    Strong antiresonant reflecting optical waveguiding is demonstrated in a novel poly (methyl-methacrylate) (PMMA) hollow-core fiber. The transmission spectrum of the fiber was characterized using a supercontinuum source and it revealed distinct resonances with resonant dips as strong as ~20 d......B in the wavelength range 480-900 nm, where PMMA has low absorption. The total propagation loss of the fiber was measured to have a minimum of ~45 dB m-1 at around 500 nm. The thermal sensitivity of the fiber is 256 ± 16 pm °C-1, defined as the red-shift of the resonances per °C, which is three times higher than...... the sensitivity of polymer fiber Bragg gratings....

  2. Novel systems for tailored neurotrophic factor release based on hydrogel and resorbable glass hollow fibers.

    Science.gov (United States)

    Novajra, G; Tonda-Turo, C; Vitale-Brovarone, C; Ciardelli, G; Geuna, S; Raimondo, S

    2014-03-01

    A novel system for the release of neurotrophic factor into a nerve guidance channel (NGC) based on resorbable phosphate glass hollow fibers (50P2O5-30CaO-9Na2O-3SiO2-3MgO-2.5K2O-2.5TiO2 mol%) in combination with a genipin-crosslinked agar/gelatin hydrogel (A/G_GP) is proposed. No negative effect on the growth of neonatal olfactory bulb ensheathing cell line (NOBEC) as well as on the expression of pro- and anti-apoptotic proteins was measured in vitro in the presence of fiber dissolution products in the culture medium. For the release studies, fluorescein isothiocyanate-dextran (FD-20), taken as growth factor model molecule, was solubilized in different media and introduced into the fiber lumen exploiting the capillary action. The fibers were filled with i) FD-20/phosphate buffered saline (PBS) solution, ii) FD-20/hydrogel solution before gelation and iii) hydrogel before gelation, subsequently lyophilized and then filled with the FD-20/PBS solution. The different strategies used for the loading of the FD-20 into the fibers resulted in different release kinetics. A slower release was observed with the use of A/G_GP hydrogel. At last, poly(ε-caprolactone) (PCL) nerve guides containing the hollow fibers and the hydrogel have been fabricated.

  3. Nonlinear endoscopy with Kagomé lattice hollow-core fibers (Conference Presentation)

    Science.gov (United States)

    Lombardini, Alberto; Sivankutty, Siddharth; Chen, Xueqin; Wenger, Jérôme; Habert, Rémi; Fourcade-Dutin, Coralie; Andresen, Esben R.; Kudlinski, Alexandre; Rigneault, Hervé

    2016-03-01

    The development of nonlinear fiber-endoscopes capable of imaging deeper in tissues and accessing internal organs represents a very attractive perspective for application of nonlinear optical microscopes to in-vivo research and diagnostics. The transmission of ultra-short laser pulses within a fiber is a critical issue in the development of such endoscopes. For instance, self-phase modulation (SPM), four-wave mixing (FWM) and Raman scattering occurring in conventional fibers severely affect transmitted pulses profiles in the time and frequency domains. Hollow-core (HC) fibers bring a solution to the problem, since propagation of the pulses in the air core limits nonlinear interactions. We employ here a novel double clad Kagomé-lattice HC fiber for the delivery of ultrafast pulses across a large spectral window (~400nm) with no pulse distortion. The epi-collection of the signal generated at the sample is efficiently performed with a specially designed outer multimode cladding. The fiber is incorporated in a prototype endoscope using a four-quartered piezo-electric tube to scan the laser beam on the sample. The low numerical aperture of the hollow-core (0.02) is efficiently increased by means of a dielectric microsphere attached to the fiber face. This results in tight focusing (~1 micron) of the beam at the HC fiber output. Resonant scanning of the fiber tip allows imaging over a field of 300 microns using low driving voltages. High-resolution images with different contrast mechanisms, such as SHG and TPEF, acquired with the prototype endoscope illustrate the potential of these fibers for nonlinear imaging in regions otherwise inaccessible to conventional optical microscopes.

  4. Study on the enrichment of Sulfur Hexafluoride in the tmosphere through polyimide hollow fiber membrane

    Directory of Open Access Journals (Sweden)

    Wang Weixian

    2016-01-01

    Full Text Available Sulfur hexafluoride is per molecule the strongest greenhouse gas know, the features have brought SF6 into the climatic impact discussion aimed at reduction of emissions. The separation effects of sulfur hexafluoride in the atmosphere are studied through polyimide hollow fiber membrane with different conditions on pressure drop, gas flow and temperature. The sulfur hexafluoride concentration increased with increased pressure drop of the membrane, increased temperature and decreased non-filtrate flow flux; the recovery of sulfur hexafluoride exceeds 93%, enrichment coefficient was 18.5; sulfur hexafluoride is not detected at the flux of the filtrate flow, which means sulfur hexafluoride is riddled by membrane. The results showed that polyimide hollow fiber membrane can effectively separate sulfur hexafluoride from mixed gas

  5. Integrated hollow fiber membranes for gas delivery into optical waveguide based photobioreactors.

    Science.gov (United States)

    Ahsan, Syed Saad; Gumus, Abdurrahman; Jain, Aadhar; Angenent, Largus T; Erickson, David

    2015-09-01

    Compact algal reactors are presented with: (1) closely stacked layers of waveguides to decrease light-path to enable larger optimal light-zones; (2) waveguides containing scatterers to uniformly distribute light; and (3) hollow fiber membranes to reduce energy required for gas transfer. The reactors are optimized by characterizing the aeration of different gases through hollow fiber membranes and characterizing light intensities at different culture densities. Close to 65% improvement in plateau peak productivities was achieved under low light-intensity growth experiments while maintaining 90% average/peak productivity output during 7-h light cycles. With associated mixing costs of ∼ 1 mW/L, several magnitudes smaller than closed photobioreactors, a twofold increase is realized in growth ramp rates with carbonated gas streams under high light intensities, and close to 20% output improvement across light intensities in reactors loaded with high density cultures.

  6. Effects of CO 2 on a High Performance Hollow-Fiber Membrane for Natural Gas Purification

    KAUST Repository

    Omole, Imona C.

    2010-05-19

    A 6FDA-based, cross-linkable polyimide was characterized in the form of a defect-free asymmetric hollow-fiber membrane. The novel membrane was cross-linked at various temperatures and tested for natural gas purification in the presence of high CO2 partial pressures. The cross-linked membrane material shows high intrinsic separation performance for CO2 and CH4 (selectivity ∼49, CO2 permeability ∼161 barrer, with a feed at 65 psia, 35 °C, and 10% CO2). Cross-linked asymmetric hollow-fiber membranes made from the material show good resistance to CO2-induced plasticization. Carbon dioxide partial pressures as high as ∼400 psia were employed, and the membrane was shown to be promisingly stable under these aggressive conditions. The performance of the membrane was also analyzed using the dual-mode sorption/transport model. © 2010 American Chemical Society.

  7. Combined organic-inorganic fouling of forward osmosis hollow fiber membranes.

    Science.gov (United States)

    Arkhangelsky, Elizabeth; Wicaksana, Filicia; Tang, Chuyang; Al-Rabiah, Abdulrahman A; Al-Zahrani, Saeed M; Wang, Rong

    2012-12-01

    This research focused on combined organic-inorganic fouling and cleaning studies of forward osmosis (FO) membranes. Various organic/inorganic model foulants such as sodium alginate, bovine serum albumin (BSA) and silica nanoparticles were applied to polyamide-polyethersulfone FO hollow fiber membranes fabricated in our laboratory. In order to understand all possible interactions, experiments were performed with a single foulant as well as combinations of foulants. Experimental results suggested that the degree of FO membrane fouling could be promoted by synergistic effect of organic foulants, the presence of divalent cations, low cross-flow velocity and high permeation drag force. The water flux of fouled FO hollow fibers could be fully restored by simple physical cleaning. It was also found that hydrodynamic regime played an important role in combined organic-inorganic fouling of FO membranes.

  8. PVDF hollow fiber and nanofiber membranes for fresh water reclamation using membrane distillation

    KAUST Repository

    Francis, Lijo

    2013-11-26

    Polyvinylidene fluoride hollow fiber and nanofibrous membranes are engineered and successfully fabricated using dry-jet wet spinning and electrospinning techniques, respectively. Fabricated membranes are characterized for their morphology, average pore size, pore size distribution, nanofiber diameter distribution, thickness, and water contact angle. Direct contact membrane distillation (DCMD) performances of the fabricated membranes have been investigated using a locally designed and fabricated, fully automated MD bench scale unit and DCMD module. Electrospun nanofibrous membranes showed a water flux as high as 36 L m-2 h-1 whereas hollow fiber membranes showed a water flux of 31.6 L m-2 h-1, at a feed inlet temperature of 80 °C and at a permeate inlet temperature of 20 °C.

  9. Development and characterization of polyacrylonitrile (PAN based carbon hollow fiber membrane

    Directory of Open Access Journals (Sweden)

    Syed Mohd Saufi

    2002-11-01

    Full Text Available This paper reports the development and characterization of polyacrylonitrile (PAN based carbon hollow fiber membrane. Nitrogen was used as an inert gas during pyrolysis of the PAN hollow fiber membrane into carbon membrane. PAN membranes were pyrolyzed at temperature ranging from 500oC to 800oC for 30 minutes of thermal soak time. Scanning Electron Microscope (SEM, Fourier Transform Infrared Spectroscopy (FTIR and gas sorption analysis were applied to characterize the PAN based carbon membrane. Pyrolysis temperature was found to significantly change the structure and properties of carbon membrane. FTIR results concluded that the carbon yield still could be increased by pyrolyzing PAN membranes at temperature higher than 800oC since the existence of other functional group instead of CH group. Gas adsorption analysis showed that the average pore diameter increased up to 800oC.

  10. Electrochemically Active Polymeric Hollow Fibers based on Poly(ether- b -amide)/Carbon Nanotubes

    KAUST Repository

    Cuevas, Carolina

    2017-09-18

    A simple and effective method to incorporate catalytic activity to a hollow fiber membrane is reported. Polyetherimide hollow fiber membranes were coated with a solution containing carboxyl-functionalized multi-walled carbon nanotubes and poly(ether-b-amide). Electron microscopy images confirmed the presence of a layer of percolating carbon nanotubes on the surface of the membranes. Cyclic voltammetry and linear swept voltammetry experiments showed that these membranes are able to drive the reactions of hydrogen evolution, and oxygen reduction, making them a cheaper, and greener substitute for platinum based cathodes in microbial bioelectrochemical systems. Water flux and molecular weight cut off experiments indicated that the electrochemically active coating layer does not affect the ultrafiltration performance of the membrane.

  11. Influence of air pressure on soliton formation in hollow-core photonic bandgap fibers

    DEFF Research Database (Denmark)

    Lægsgaard, Jesper; Roberts, Peter John

    2009-01-01

    Abstract Soliton formation during dispersive compression of chirped few-picosecond pulses at the microjoule level in a hollow-core photonic bandgap (HC-PBG) fiber is studied by numerical simulations. Long-pass filtering of the emerging frequency-shifted solitons is investigated with the objective...... at high powers. This allows a scaling of the output pulse energy toward the microjoule level. © 2009 Optical Society of America...

  12. Enhanced Membrane Treatment for Hollow-Fiber Microfiltration in Ultrasonic Reflection Field

    Science.gov (United States)

    Kobayashi, Takaomi; Hosaka, Yoho

    2003-05-01

    The effect of ultrasound on the enhanced membrane treatment process was controlled by the reflection of 28 kHz ultrasound onto the vicinity of a hollow-fiber microfiltration membrane. When a stainless reflection plate was placed behind the membrane module, the resultant permeation flux of the membrane was changed in the ultrasonic reflection field. We found that a semicylindrical reflection plate could highly enhance the membrane cleaning process.

  13. Research of the DC discharge of He-Ne gas mixture in hollow core fiber

    Science.gov (United States)

    Wang, Xinbing; Duan, Lian

    2013-09-01

    Since the first waveguide 0.633 μm He-Ne laser from a 20 cm length of 430 μm glass capillary was reported in 1971, no smaller waveguide gas laser has ever been constructed. Recently as the development of low loss hollow core PBG fiber, it is possible to constract a He-Ne lasers based on hollow-core PBG fibers. For the small diameter of the air hole, it is necessary to do some research to obtain glow discharge in hollow core fibers. In this paper, the experimental research of DC discharge in 200 μm bore diameter hollow core fibers was reported. Stable glow discharge was obained at varioue He-Ne mixtures from 4 Torr to 18 Torr. In order to obtain the plasma parameter of the discharge, the trace gasses of N2 and H2 were added to the He-Ne mixtures, the optical emission spectroscopy of the discharge was recorded by a PI 2750 spectroscopy with a CCD camera. The gas temperature (Tg) could be obtained by matching the simulated rovibronic band of the N2 emission with the observed spectrum in the ultraviolet region. The spectral method was also used to obtained the electron density, which is based on the analysis of the wavelength profile of the 486.13 nm Hβ line, and the electron temperature was obtain by Boltzmann plot methods. Experimental results show that it is very difficult to achieve DC discharge in bore diameter less than 50 μm, and a RF discharge method was proposed. Project supported by the National Natural Science Foundation of China (61078033).

  14. Optical fiber sensors using hollow glass spheres and CCD spectrometer interrogator

    Science.gov (United States)

    Dakin, John P.; Ecke, Wolfgang; Schroeder, Kerstin; Reuter, Martin

    2009-10-01

    Hollow glass micro-spheres, firstly used to make fiber optic sensors for high hydrostatic pressure, have been interrogated using a high-resolution CCD-based spectrometer, to give far better precision than conventional spectrometric read out. It is found that these simple, low-cost micro-sensors have excellent sensitivity to both static and dynamic pressure, and have the advantage of being hermetically sealed. Many other application areas are foreseen for these low-cost sensors.

  15. FEM investigation of leaky modes in hollow core photonic crystal fibers

    OpenAIRE

    Pomplun, J.; Holzlöhner, R.; Burger, S.; Zschiedrich, L.; Schmidt, F

    2007-01-01

    Hollow-core holey fibers are promising candidates for low-loss guidance of light in various applications, e.g., for the use in laser guide star adaptive optics systems in optical astronomy. We present an accurate and fast method for the computation of light modes in arbitrarily shaped waveguides. Maxwell's equations are discretized using vectorial finite elements (FEM). We discuss how we utilize concepts like adaptive grid refinement, higher-order finite elements, and transparent boundary con...

  16. Accelerating Solitons in Gas-Filled Hollow-Core Photonic Crystal Fibers

    CERN Document Server

    Facao, M; Almeida, P

    2013-01-01

    We found the self-similar solitary solutions of a recently proposed model for propagation of pulses in gas filled hollow-core photonic crystal fibers that includes a plasma induced nonlinearity. As anticipated for a simpler model and using a perturbation analysis, there are indeed stationary solitary waves that accelerate and self-shift to higher frequencies. However, if the plasma nonlinearity strength is large or the pulse amplitudes are small, the solutions have distinguished long tails and decay as they propagate.

  17. Characterization of polyethersulfone-polyimide hollow fiber membranes by atomic force microscopy and contact angle goniometery

    OpenAIRE

    Khulbe, K.C.; Feng, C.; Matsuura, T.; Kapantaidakis, G.; Wessling, Matthias; Koops, G.H.

    2003-01-01

    Asymmetric blend polyethersulfone-polyimide (PES-PI) hollow fiber membranes prepared at different air gap and used for gas separation are characterized by atomic force microscopy (inside and out side surfaces) and by measuring the contact angle of out side surface. The outer surface was entirely different than the inner surface, as expected. On the inner surface nodule aggregates were aligned in rows, may be towards the direction of the bore fluid flow. On the outer surface, alignment of nodu...

  18. Bench Scale Thin Film Composite Hollow Fiber Membranes for Post-Combustion Carbon Dioxide Capture

    Energy Technology Data Exchange (ETDEWEB)

    Glaser, Paul [General Electric Global Research, Niskayuna, NY (United States); Bhandari, Dhaval [General Electric Global Research, Niskayuna, NY (United States); Narang, Kristi [General Electric Global Research, Niskayuna, NY (United States); McCloskey, Pat [General Electric Global Research, Niskayuna, NY (United States); Singh, Surinder [General Electric Global Research, Niskayuna, NY (United States); Ananthasayanam, Balajee [General Electric Global Research, Niskayuna, NY (United States); Howson, Paul [General Electric Global Research, Niskayuna, NY (United States); Lee, Julia [General Electric Global Research, Niskayuna, NY (United States); Wroczynski, Ron [General Electric Global Research, Niskayuna, NY (United States); Stewart, Frederick [Idaho National Lab. (INL), Idaho Falls, ID (United States); Orme, Christopher [Idaho National Lab. (INL), Idaho Falls, ID (United States); Klaehn, John [Idaho National Lab. (INL), Idaho Falls, ID (United States); McNally, Joshua [Idaho National Lab. (INL), Idaho Falls, ID (United States); Rownaghi, Ali [Georgia Inst. of Technology, Atlanta, GA (United States); Lu, Liu [Georgia Inst. of Technology, Atlanta, GA (United States); Koros, William [Georgia Inst. of Technology, Atlanta, GA (United States); Goizueta, Roberto [Georgia Inst. of Technology, Atlanta, GA (United States); Sethi, Vijay [Western Research Inst., Laramie, WY (United States)

    2015-04-01

    GE Global Research, Idaho National Laboratory (INL), Georgia Institute of Technology (Georgia Tech), and Western Research Institute (WRI) proposed to develop high performance thin film polymer composite hollow fiber membranes and advanced processes for economical post-combustion carbon dioxide (CO2) capture from pulverized coal flue gas at temperatures typical of existing flue gas cleanup processes. The project sought to develop and then optimize new gas separations membrane systems at the bench scale, including tuning the properties of a novel polyphosphazene polymer in a coating solution and fabricating highly engineered porous hollow fiber supports. The project also sought to define the processes needed to coat the fiber support to manufacture composite hollow fiber membranes with high performance, ultra-thin separation layers. Physical, chemical, and mechanical stability of the materials (individual and composite) towards coal flue gas components was considered via exposure and performance tests. Preliminary design, technoeconomic, and economic feasibility analyses were conducted to evaluate the overall performance and impact of the process on the cost of electricity (COE) for a coal-fired plant including capture technologies. At the onset of the project, Membranes based on coupling a novel selective material polyphosphazene with an engineered hollow fiber support was found to have the potential to capture greater than 90% of the CO2 in flue gas with less than 35% increase in COE, which would achieve the DOE-targeted performance criteria. While lab-scale results for the polyphosphazene materials were very promising, and the material was incorporated into hollow-fiber modules, difficulties were encountered relating to the performance of these membrane systems over time. Performance, as measured by both flux of and selectivity for CO2 over other flue gas constituents was found to deteriorate over time, suggesting a system that was

  19. Design of robust hollow fiber membranes with high power density for osmotic energy production

    KAUST Repository

    Zhang, Sui

    2014-04-01

    This study highlights the design strategy of highly asymmetric hollow fiber membranes that possess both characteristics of high flux and high mechanical strength to effectively reap the osmotic energy from seawater brine with an ultrahigh power density. An advanced co-extrusion technology was employed to fabricate the polyethersulfone (PES) hollow fiber supports with diversified structures from macrovoid to sponge-like. The microstructure of the supports is found critical for the stability and water permeability of the thin film composite (TFC) membranes. A high porosity in the porous layer is needed to reduce internal concentration polarization, while a thick and relatively dense skin layer underneath the TFC layer is required to maintain good mechanical stability and stress dissipation. The pore size of the supporting layer underneath the TFC layer must be small with a narrow pore size distribution to ensure the formation of a less-defective, highly permeable and mechanically stable TFC layer. The newly developed hollow fiber comprising high asymmetry, high porosity, and a thick skin layer with a small and narrow pore size distribution underneath the TFC layer produces a maximum power density of 24.3W/m2 at 20.0bar by using 1M NaCl as the concentrated brine and deionized (DI) water as the feed. The proposed design strategy for ultrahigh power density membranes clearly advances the osmotic energy production close to commercialization with a quite cost-effective and practicable approach. © 2013 Elsevier B.V.

  20. Monitoring of polymeric membrane fouling in hollow fiber module using ultrasonic nondestructive testing

    Institute of Scientific and Technical Information of China (English)

    LIU Jing-xia; LI Jian-xin; CHEN Xue-mei; ZHANG Yu-zhong

    2006-01-01

    This study describes the development of novel protocols extending the real-time ultrasonic reflectometry(UTDR) for the detection of membrane fouling in hollow fiber module during ultrafiltration(UF) of oily water treatment. A specially designed acoustic sensor with a frequency of 2.5 MHz was used. The hollow fiber membranes used were polysulphone(PSf) UF membranes with MWCO 40 kDa. The wastewaters with three different oily concentrations of 100,500 and 1 000 mg/L were investigated. Diesel oil was utilized as the primary foulant. The results show that the permeate flux declines with operation time and its value becomes lower with the increase of the oily concentration in wastewater. It is found that ultrasonic measurement can detect the fouling and cleaning processes. A new signal analysis protocol-ultrasonic reflected energy was developed. Ultrasonic reflected energy obtained indicates the deposition of oily layer as a function of operation time and its removal after cleaning. The overall flux decline is reasonably correlated with the changes in ultrasonic reflected energy. This research provides the evidence that the ultrasonic reflectometry technique is capable of monitoring membrane fouling and cleaning in hollow fiber modules.

  1. Green Modification of Outer Selective P84 Nanofiltration (NF) Hollow Fiber Membranes for Cadmium Removal

    KAUST Repository

    Gao, Jie

    2015-10-26

    Outer-selective thin-film composite (TFC) hollow fiber membranes are normally made from interfacial polymerization of m-phenylenediamine (MPD) and trimesoyl chloride (TMC). However, the removal of excess MPD solution and the large consumption of alkane solvents are their technical bottlenecks. In this study, green methods to prepare the outer selective TFC hollow fiber membranes were explored by firstly modifying the membrane substrate with polyethyleneimine (PEI) and then by water soluble small molecules such as glutaraldehyde (GA) and epichlorohydrin (ECH). Using P84 polyimide as the substrate, not only do these modifications decrease substrate\\'s pore size, but also vary surface charge by making the membranes less positively charged. As a result, the resultant membranes have higher rejections against salts such as Na2SO4, NaCl and MgSO4. The PEI and then GA modified membrane has the best separation performance with a NaCl rejection over 90% and a pure water permeability (PWP) of 1.74±0.01 Lm−2bar−1h−1. It also shows an impressive rejection to CdCl2 (94%) during long-term stability tests. The CdCl2 rejection remains higher than 90% at operating temperatures from 5 to 60 °C. This study may provide useful insights for green manufacturing of outer-selective nanofiltration (NF) hollow fiber membranes.

  2. A simple sample preparation method for measuring amoxicillin in human plasma by hollow fiber centrifugal ultrafiltration.

    Science.gov (United States)

    Dong, Wei-Chong; Hou, Zi-Li; Jiang, Xin-Hui; Jiang, Ye

    2013-02-01

    A simple sample preparation method has been developed for the determination of amoxicillin in human plasma by hollow fiber centrifugal ultrafiltration (HF-CF-UF). A 400-μL plasma sample was placed directly into the HF-CF-UF device, which consisited of a slim glass tube and a U-shaped hollow fiber. After centrifugation at 1.25 × 10(3) g for 10 min, the filtrate was withdrawn from the hollow fiber and 20 µL was directly injected into the high-performance liquid chromatography (HPLC) for analysis. The calibration curve was linear over the range of 0.1-20 µg/mL (r = 0.9996) and the limit of detection was as low as 0.025 µg/mL. The average recovery and absolute recovery were 99.9% and 84.5%, respectively. Both the intra-day and inter-day precisions (relative standard deviation) were less than 3.1% for three concentrations (0.25, 2.5 and 10 µg/mL). The sample preparation process was simplified. Only after a single centrifugal ultrafiltration can the filtrate be injected directly into HPLC. The present method is simple, sensitive and accurate. It could be effective for the analysis of biological samples with high protein contents, especially for the biopharmaceutical analysis of drugs that use traditional isolation techniques for sample preparation such as the protein precipitation method.

  3. Experimental investigation on liquid-phase fabrication techniques for multilayer infrared hollow fiber

    Science.gov (United States)

    Sun, Bang-Shan; Zeng, Xuan; Iwai, Katsumasa; Miyagi, Mitsunobu; Chi, Nan; Shi, Yi-Wei

    2011-07-01

    Infrared hollow fiber with metal and dielectric inner-coatings has found applications in medical and industrial fields. It is a commonly used method to lower the loss by inner-coating multi dielectric layers. In this paper, SiO 2 and AgI were selected to fabricate the multilayer mid-infrared hollow fiber. Liquid-phase coating techniques were experimentally discussed in order to control the film thickness. It is shown that concentration and flow speed of the coating solution are key parameters to modify SiO 2 film thickness. AgI film was obtained by firstly coating a silver layer and then iodinating the silver layer into AgI. SiO 2 and AgI films were deposited orderly on the inner wall of a 0.7-mm bore glass capillary. Both thicknesses for SiO 2 and AgI films were well controlled and optimized according to the theoretical calculation. The measured infrared loss spectrum of SiO 2/AgI/SiO 2/Ag multilayer hollow fiber has a good agreement with the calculated result and shows band gap effect around the wavelength of 5.3 μm.

  4. Preparation of hydrophilic vinyl chloride copolymer hollow fiber membranes with antifouling properties

    Science.gov (United States)

    Rajabzadeh, Saeid; Sano, Rie; Ishigami, Toru; Kakihana, Yuriko; Ohmukai, Yoshikage; Matsuyama, Hideto

    2015-01-01

    Hydrophilic vinyl chloride copolymer hollow fiber membranes with antifouling properties were prepared from brominated vinyl chloride-hydroxyethyl methacrylate copolymer (poly(VC-co-HEMA-Br)). The base membrane was grafted with two different zwitterionic monomers, (2-methacryloyloxyethylphosphorylcholine) (MPC) and [2-(methacryloyloxy) ethyl] dimethyl (3-sulfopropyl) ammonium hydroxide) (MEDSAH), and poly(ethylene glycol) methyl ether methacrylate (PEGMA). The effect of the grafting on the base membrane hydrophilicity and antifouling properties was investigated. For comparison of the results, the pure water permeabilities and pore sizes at the outer surfaces of the grafted hollow fiber membranes were controlled to be similar. A poly(VC-co-HEMA-Br) hollow fiber membrane with similar pure water permeability and pore size was also prepared as a control membrane. A BSA solution was used as a model fouling solution for evaluation of the antifouling properties. Grafting with zwitterionic monomers and PEGMA improved the antifouling properties compared with the control membrane. The PEGMA grafted membrane showed the best antifouling properties among the grafted membranes

  5. Recovery of Copper Ions from Wastewater by Hollow Fiber Supported Emulsion Liquid Membrane

    Institute of Scientific and Technical Information of China (English)

    郑辉东; 陈晶晶; 王碧玉; 赵素英

    2013-01-01

    Recovery of copper ions from wastewater using a hollow fiber supported emulsion liquid membrane (HFSELM) was studied with LIX984N as carrier, kerosene as diluents, and sulfuric acid solution as stripping phase. Effects of compositions of feed and emulsion liquid phase, flow rates on both sides of membrane, and hollow fiber module parameters were investigated. The stability of the emulsion liquid phase without surfactant and the effect of buffer in the feed phase on the extraction rate were also evaluated. It is found that the stability of the emulsion phase without surfactant is poor. Higher flow velocity gives shorter residence time for the emulsion liquid phase on the tube side, reducing the effect of particle coalescence on the separation process. The extraction rate increases with the increase of feed phase pH, carrier concentration, hydrogen ion concentration in the stripping phase, and ef-fective hollow fiber area. The phase ratio in the emulsion liquid phase has a negative effect on extraction rate. The flow rates on both sides have little influence on the extraction performance of the HFSELM, while buffer addition in the feed solution improves the extraction efficiency.

  6. Hollow fibers made from a poly(3-hydroxybutyrate/poly-ε-caprolactone blend

    Directory of Open Access Journals (Sweden)

    2011-07-01

    Full Text Available Since poly(3-hydroxybutyrate (PHB is inherently brittle and possesses poor elastic properties, hollow fibers produced by melt spinning from pure PHB, as described in our earlier study [Macromolecular Materials and Engineering, 2010, 295/6, 585–594], do not meet the required needs regarding the mechanical performance. Besides hardly available PHB copolymers, also blend systems are known to enhance material properties and have thus been considered to be eligible to fabricate flexible or rather pliable hollow fibers based on PHB. Blends of PHB and poly-!-caprolactone (PCL are promising for the application in tissue engineering due to the inherent biocompatibility and biodegradability. A wide range of PHB/PCL compositions have been prepared by melt extrusion. Thermal and mechanical properties of the obtained specimens were analyzed in order to identify miscibility and degree of dispersion as well as to determine the influence on the overall mechanical performance. Even though these constituents are known to be immiscible, PHB/PCL 70/30 was proven to be an adequate composition. This blend showed a highly increased elongation and was found to be easily processable by melt spinning compared to pure PHB. From this blend well defined dimensionally stable bendable hollow fibers were fabricated.

  7. Air-bubbling, hollow-fiber reactor with cell bleeding and cross-flow filtration.

    Science.gov (United States)

    Nishii, K; Sode, K; Karube, I

    1990-05-01

    Continuous asymmetric reduction of dyhydrooxoisophorone (DOIP) to 4-hydroxy-2,2,6-trimethylcyclo-hexanone (4-HTMCH) was achieved by a thermophilic bacterium Bacillus stearothermophilus NK86-0151. Three reactors were used: an air-bubbling hollow-fiber reactor with cell bleeding and cross-flow filtration, an air-lift reactor, and a CSTR with PAA immobilized cells. The maximum cell concentration of 11.1 g dry wt L(-1) was obtained in an air-bubbling hollow-fiber reactor, while in the other reactors the cell densities were between 3.5 and 4.1 g dry wt L(-1) The optimum bleed ratio was 0.1 at the dilution rate 0.3 h(-1) in the hollow-fiber reactor. The highest viable cell concentration was maintained in the dilution range of 0.4-0.7 h(-1) by a combination of proper cell bleeding and cross-flow filtration. The maximum volumetric productivity of 4-HTMCH reached 826 mg L(-1) h(-1) at the dilution rate 0.54 h(-1). This value was 4 and 2 times higher than those in the air-lift reactor and CSTR, respectively. The increasing viable cell concentration increased the volumetric productivity of 4-HTMCH. A cell free product solution was continuously obtained by cross-flow filtration.

  8. Nonlinear compression of ultrafast industrial lasers in hypocyloid-core Kagome hollow-core fiber

    Science.gov (United States)

    Giree, A.; Guichard, F.; Machinet, G.; Zaouter, Y.; Hagen, Y.; Debords, B.; Dupriez, P.; Gérôme, F.; Hanna, M.; Benabid, F.; Hönninger, C.; Georges, P.; Mottay, E.

    2015-03-01

    The duration of energetic ultrashort pulses is usually limited by the available gain bandwidth of ultrashort amplifiers used to amplify nJ or pJ level seed to hundreds of μμJ or even several mJ. In the case of Ytterbium-doped fiber amplifiers, the available bandwidth is of the order of 40 nm, typically limiting the pulse duration of high-energy fiber chirped-pulse amplifiers to durations above 300 fs. In the case of solid-state amplifier based on Yb:YAG crystals, the host matrix order restricts the amplification bandwidth even more leading to pulses in the low picosecond range. Both architecture would greatly benefit from pulse durations well-below what is allowed by their respective gain bandwidth e.g. sub-100 fs for fiber amplifier and sub-300 fs for solid-state Yb:YAG amplifier. In this contribution, we report on the post-compression of two high energy industrial ultrashort fiber and thin-disk amplifiers using an innovative and efficient hollow core fiber structure, namely the hypocycloid-core Kagome fiber. This fiber exhibits remarkably low propagation losses due to the unique inhibited guidance mechanism that minimize that amount of light propagating in the silica cladding surrounding the hollow core. Spectral broadening is realized in a short piece of Kagome fiber filled with air at 1 atmosphere pressure. For both amplifiers, we were able to demonstrate more than 200 μJ of energy per pulse with duration <100 fs in the case of the fiber amplifier and <300 fs in the case of the thin disk amplifier. Limitations and further energy scaling will also be discussed.

  9. Characterization of miniature fiber-optic Fabry-Perot interferometric sensors based on hollow silica tube

    Science.gov (United States)

    Jia, Pinggang; Fang, Guocheng; Wang, Daihua

    2016-09-01

    A miniature fiber-optic Fabry-Perot interferometer (MOFPI) fabricated by splicing a hollow silica tube (HST) with inner diameter of 4 µm to the end of a single-mode fiber is investigated and experimentally demonstrated. The theoretical relationship between the free spectrum range and the length of HST is verified by fabricating several MOFPIs with different lengths. We characterize the MOFPIs for temperature, liquid refractive index, and strain. Experimental results show that the sensitivities of the temperature, liquid refractive index, and strain are 16.42 pm/°C,-118.56 dB/RIU, and 1.21 pm/µɛ, respectively.

  10. Design of low-loss and highly birefringent hollow-core photonic crystal fiber

    DEFF Research Database (Denmark)

    Roberts, Peter John; Williams, D.P.; Sabert, H.;

    2006-01-01

    A practical hollow-core photonic crystal fiber design suitable for attaining low-loss propagation is analyzed. The geometry involves a number of localized elliptical features positioned on the glass ring that surrounds the air core and separates the core and cladding regions. The size of each...... feature is tuned so that the composite core-surround geometry is antiresonant within the cladding band gap, thus minimizing the guided mode field intensity both within the fiber material and at material / air interfaces. A birefringent design, which involves a 2-fold symmetric arrangement of the features...

  11. Identification of Bloch-modes in hollow-core Photonic Crystal Fiber cladding

    DEFF Research Database (Denmark)

    Couny, F.; Benabid, F.; Roberts, John;

    2007-01-01

    length of fiber. A detailed study of the modes near the edges of the band gap shows that it is formed by the influence of three types of resonator: the glass interstitial apex, the silica strut which joins the neighboring apexes, and the air hole. The cladding electromagnetic field which survives......We report on the experimental visualization of the cladding Bloch-modes of a hollow-core photonic crystal fiber. Both spectral and spatial field information is extracted using the approach, which is based on measurement of the near-field and Fresnel-zone that results after propagation over a short...

  12. Oxygen Transfer Model for a Flow-Through Hollow-Fiber Membrane Biofilm Reactor

    DEFF Research Database (Denmark)

    Gilmore, K. R.; Little, J. C.; Smets, Barth F.

    2009-01-01

    A mechanistic oxygen transfer model was developed and applied to a flow-through hollow-fiber membrane-aerated biofilm reactor. Model results are compared to conventional clean water test results as well as performance data obtained when an actively nitrifying biofilm was present on the fibers....... With the biofilm present, oxygen transfer efficiencies between 30 and 55% were calculated from the measured data including the outlet gas oxygen concentration, ammonia consumption stoichiometry, and oxidized nitrogen production stoichiometry, all of which were in reasonable agreement. The mechanistic model...

  13. Broadband micro-Michelson interferometer with multi-optical-path beating using a sphered-end hollow fiber.

    Science.gov (United States)

    Chen, Nan-Kuang; Lu, Kuan-Yi; Shy, Jow-Tsong; Lin, Chinlon

    2011-06-01

    We demonstrate a high-sensitivity broadband (1250-1650 nm) fiber micro-Michelson interferometer using a single-mode fiber end-spliced with a sphered-end hollow-core fiber. The hollow core is slightly smaller than the solid core of a single-mode fiber, so the fractional power of the core mode is converted into cladding modes. The excited cladding modes propagate at distinct optical paths along the hollow-core fiber and have individual foci outside the spherical lens. The reflected core mode, generated at the solid core-air interface, and the reflected cladding modes, generated at external material, interfere with each other to produce beating in the interference signals.

  14. Silica-glass contribution to the effective nonlinearity of hollow-core photonic band-gap fibers.

    Science.gov (United States)

    Hensley, Christopher J; Ouzounov, Dimitre G; Gaeta, Alexander L; Venkataraman, Natesan; Gallagher, Michael T; Koch, Karl W

    2007-03-19

    We measure the effective nonlinearity of various hollow-core photonic band-gap fibers. Our findings indicate that differences of tens of nanometers in the fiber structure result in significant changes to the power propagating in the silica glass and thus in the effective nonlinearity of the fiber. These results show that it is possible to engineer the nonlinear response of these fibers via small changes to the glass structure.

  15. Optical trapping and control of nanoparticles inside evacuated hollow core photonic crystal fibers

    Energy Technology Data Exchange (ETDEWEB)

    Grass, David, E-mail: david.grass@univie.ac.at; Fesel, Julian; Hofer, Sebastian G.; Kiesel, Nikolai; Aspelmeyer, Markus, E-mail: markus.aspelmeyer@univie.ac.at [Vienna Center for Quantum Science and Technology (VCQ), Faculty of Physics, University of Vienna, A-1090 Vienna (Austria)

    2016-05-30

    We demonstrate an optical conveyor belt for levitated nanoparticles over several centimeters inside both air-filled and evacuated hollow-core photonic crystal fibers (HCPCF). Detection of the transmitted light field allows three-dimensional read-out of the particle center-of-mass motion. An additional laser enables axial radiation pressure based feedback cooling over the full fiber length. We show that the particle dynamics is a sensitive local probe for characterizing the optical intensity profile inside the fiber as well as the pressure distribution along the fiber axis. In contrast to some theoretical predictions, we find a linear pressure dependence inside the HCPCF, extending over three orders of magnitude from 0.2 mbar to 100 mbar. A targeted application is the controlled delivery of nanoparticles from ambient pressure into medium vacuum.

  16. Fluorescence-based remote irradiation sensor in liquid-filled hollow-core photonic crystal fiber

    Science.gov (United States)

    Zeltner, R.; Bykov, D. S.; Xie, S.; Euser, T. G.; Russell, P. St. J.

    2016-06-01

    We report an irradiation sensor based on a fluorescent "flying particle" that is optically trapped and propelled inside the core of a water-filled hollow-core photonic crystal fiber. When the moving particle passes through an irradiated region, its emitted fluorescence is captured by guided modes of the fiber core and so can be monitored using a filtered photodiode placed at the fiber end. The particle speed and position can be precisely monitored using in-fiber Doppler velocimetry, allowing the irradiation profile to be measured to a spatial resolution of ˜10 μm. The spectral response can be readily adjusted by appropriate choice of particle material. Using dye-doped polystyrene particles, we demonstrate detection of green (532 nm) and ultraviolet (340 nm) light.

  17. Optical trapping and control of nanoparticles inside evacuated hollow core photonic crystal fibers

    CERN Document Server

    Grass, David; Hofer, Sebastian G; Kiesel, Nikolai; Aspelmeyer, Markus

    2016-01-01

    We demonstrate an optical conveyor belt for levitated nano-particles over several centimeters inside both air-filled and evacuated hollow-core photonic crystal fibers (HCPCF). Detection of the transmitted light field allows three-dimensional read-out of the particle center-of-mass motion. An additional laser enables axial radiation pressure based feedback cooling over the full fiber length. We show that the particle dynamics is a sensitive local probe for characterizing the optical intensity profile inside the fiber as well as the pressure distribution along the fiber axis. In contrast to previous indirect measurement methods we find a linear pressure dependence inside the HCPCF extending over three orders of magnitude from 0.2 mbar to 100 mbar. A targeted application is the controlled delivery of nano-particles from ambient pressure into medium vacuum.

  18. Impact of structural distortions on the performance of hollow-core photonic bandgap fibers.

    Science.gov (United States)

    Fokoua, Eric Numkam; Richardson, David J; Poletti, Francesco

    2014-02-10

    We present a generic model for studying numerically the performance of hollow-core photonic bandgap fibers (HC-PBGFs) with arbitrary cross-sectional distortions. Fully vectorial finite element simulations reveal that distortions beyond the second ring of air holes have an impact on the leakage loss and bandwidth of the fiber, but do not significantly alter its surface scattering loss which remains the dominant contribution to the overall fiber loss (providing that a sufficient number of rings of air holes (≥ 5) are used). We have found that while most types of distortions in the first two rings are generally detrimental, enlarging the core defect while keeping equidistant and on a circular boundary the glass nodes surrounding the core may produce losses half those compared to "idealized" fiber designs and with no penalty in terms of the transmission bandwidth.

  19. Hollow-core optical fiber incorporating a metamaterial cladding

    DEFF Research Database (Denmark)

    2010-01-01

    (221, 321, 421, 521, 621, 821) is smaller than half the wavelength l, and wherein the cladding elements (221, 321, 421, 521, 621, 821) are arranged so that transverse magnetic radiation with a wavelength of l can propagate through the core (101, 201, 301, 401, 501, 601, 801) region. The invention...... further relates to a method relating to and the use of the inventive fiber....

  20. Hollow core photonic bandgap fiber with microfluid-infiltrated air holes for slow-light propagation

    Science.gov (United States)

    Ren, Liyong; Liang, Jian; Yun, Maojin

    2012-10-01

    Slow light plays an important role in the fields of all-optical signal processing and integration photonics. It has shown many potential applications, such as realizing optical delay lines or buffers, enhancing linear and nonlinear light-matter interactions, as well as increasing the sensitivity of the interferometers and transducers. In this paper, hollow-core photonic bandgap fibers made from high index glasses are designed by infiltrating microfluid into the air-holes to tailor the fiber dispersion for slow-light propagation under low pulse distortion. In such a fiber made from Si material, group index ng~8 is obtained with a bandwidth up to 30 nm, where the group index fluctuation is restricted in ±10 % of the ng, while ng~6 is obtained with a bandwidth over 100 nm when the chalcogenide material is selected instead. Such a ±10 % criterion determines a regarded flatland region accordingly, and in this region the group velocity dispersion can be negligible. It is found that for the same fiber length the slow-light time delay in the photonic bandgap fiber is much larger as compared with that in the single mode fiber. This kind of photonic bandgap fiber may have many potential applications in short-distance fiber communications and delay lines.

  1. Bandgaps of the Chalcogenide Glass Hollow-Core Photonic Crystal Fiber

    Institute of Scientific and Technical Information of China (English)

    LI Shu-Guang; ZHOU Hong-Song; YIN Guo-Bing

    2011-01-01

    Bandgaps of chalcogenide glass hollow-core photonic crystal fibers (GLS HC-PCFs) are analyzed by using the plane-wave expansion method. A mid-infrared laser can propagate in these low confinement loss fibers when the wavelength falls into the bandgaps. For enlarging the bandgap width, an improved GLS HC-PCF is put forward, the normalized frequency kA of the improved fiber is from 7.2 to 8.5 in its first bandgap. The improved GLS HC-PCF with pitch of 4.2μm can transmit the lights with wavelengths ranging from 3.1μm to 3.7μm.%Bandgaps of chalcogenide glass hollow-core photonic crystal fibers (GLS HC-PCFs) are analyzed by using the plane-wave expansion method.A mid-infrared laser can propagate in these low confinement loss fibers when the wavelength falls into the bandgaps.For enlarging the bandgap width,an improved GLS HC-PCF is put forward,the normalized frequency κA of the improved fiber is from 7.2 to 8.5 in its first bandgap.The improved GLS HC-PCF with pitch of 4.2μm can transmit the lights with wavelengths ranging from 3.1 μm to 3.7 μm.Photonic crystal fibers (PCFs) can be classified into total internal reflection PCFs and photonic bandgap (PBG) PCFs[1] Solid core PCFs are one kind of the total internal reflection PCFs;hollow-core PCFs (HC-PCFs) are a kind of typical PBG fibers.The conception of HC-PCFs was first proposed by Russel in 1991.[2] Later,it was theoretically demonstrated by Birks et al.[3] in 1995.A bandgap photonic crystal fiber was mde by Knight et al.[4] for the first time in 1998.On the basis of these works,the first HC-PCF was designed and made by Cregan et al.[5] in 1999.

  2. All-fiber hydrogen sensor based on stimulated Raman gain spectroscopy with a 1550 nm hollow-core fiber

    CERN Document Server

    Yang, Fan

    2016-01-01

    We report a highly sensitive all-fiber hydrogen sensor based on continuous-wave stimulated Raman gain spectroscopy with a hollow-core photonic crystal fiber operating around 1550 nm. A pump-probe configuration is used, in which the frequency difference between the pump and the probe lasers is tuned to the S0(0) transition of para-hydrogen with a Raman shift of 354 cm-1. Preliminary experiments demonstrate a detection limit down to 17 ppm with a 250 s averaging time, and further improvement is possible. The all-fiber configuration operating in the telecommunication wavelength band would enable cost-effective and compact sensors for high sensitivity and high-resolution trace analysis.

  3. High-Temperature Performance and Multiscale Damage Mechanisms of Hollow Cellulose Fiber-Reinforced Concrete

    Directory of Open Access Journals (Sweden)

    Liping Guo

    2016-01-01

    Full Text Available Spalling resistance properties and their damage mechanisms under high temperatures are studied in hollow cellulose fiber-reinforced concrete (CFRC used in tunnel structures. Measurements of mass loss, relative dynamic elastic modulus, compressive strength, and splitting tensile strength of CFRC held under high temperatures (300, 600, 800, and 1050°C for periods of 2.5, 4, and 5.5 h were carried out. The damage mechanism was analyzed using scanning electron microscopy, mercury intrusion porosimetry, thermal analysis, and X-ray diffraction phase analysis. The results demonstrate that cellulose fiber can reduce the performance loss of concrete at high temperatures; the effect of holding time on the performance is more noticeable below 600°C. After exposure to high temperatures, the performance of ordinary concrete deteriorates faster and spalls at 700–800°C; in contrast, cellulose fiber melts at a higher temperature, leaving a series of channels in the matrix that facilitate the release of the steam pressure inside the CFRC. Hollow cellulose fibers can thereby slow the damage caused by internal stress and improve the spalling resistance of concrete under high temperatures.

  4. Effects of baffles on separation of aqueous ethanol solution with hollow fibers

    Institute of Scientific and Technical Information of China (English)

    Zhihong YANG; Guoliang ZHANG; Lan LIN; Danping REN; Qin MENG; Hongzi ZHANG

    2009-01-01

    The effects of baffles on the operation and mass-transfer characteristics in novel hollow fiber membrane contactor used in distillation were investi-gated. Hollow fiber membranes, coated with a 7 μmpolydimethyl-siloxane, were operated as structural packing in the separation of ethanol-water solutions. The parallel flow mode was chosen for separation due to the stronger driving force of the concentration difference, in which liquid flows through the lumens of the fibers and vapor flows countercurrent-wise outside the fibers. Two baffles were installed on the shell side of the membrane contactors to enhance separation, which had a round shape with a semi-lunar hole. The results show that both baffled and unbaffled membrane contactors gave better, more produc-tive separations than traditional packing in distillation,such as the excellent Sulzer Gauze BX structured packing.The baffled membrane contactors performed better than unbaffled ones, especially at high vapor velocities. The minimal HTU of membrane contactor with baffles could reach as low as 4.5 cm, and almost all the contactors could work well above the limit where flooding normally occurs in conventional cases. Theoretical analysis predicted that baffles helped membrane module to obtain a higher mass-transfer coefficient and a smaller mass-transfer resistance.Finally, theoretical mass-transfer coefficient and experi-mental value were compared as well as the contribution of each individual mass-transfer coefficients among liquid,gas and membrane.

  5. Characterization of Thermally Cross-Linkable Hollow Fiber Membranes for Natural Gas Separation

    KAUST Repository

    Chen, Chien-Chiang

    2013-01-23

    The performance of thermally cross-linkable hollow fiber membranes for CO2/CH4 separation and the membrane stability against CO2 plasticization was investigated. The fiber membranes were thermally cross-linked at various conditions. Cross-linking temperature was found to have a significant effect, while shorter soak time and the presence of trace oxidizer (O2 or N2O) had a negligible effect. The cross-linked fibers were tested using high CO2 content feeds (50-70% CO2) at a variety of feed pressures (up to 1000 psia), temperatures, and permeate pressures (up to 100 psia) to evaluate membrane performance under various realistic operating conditions. The results demonstrated that cross-linking improves membrane selectivity and effectively eliminates swelling-induced hydrocarbon loss at high pressures. Excellent stability under aggressive feeds (with CO2 partial pressure up to 700 psia) suggests that cross-linked hollow fiber membranes have great potential for use in diverse aggressive applications, even beyond the CO2/CH4 example explored in this work. © 2012 American Chemical Society.

  6. EFFECTS OF PRESSURE AND TEMPERATURE ON ULTRAFILTRATION HOLLOW FIBER MEMBRANE IN MOBILE WATER TREATMENT SYSTEM

    Directory of Open Access Journals (Sweden)

    ROSDIANAH RAMLI

    2016-07-01

    Full Text Available In Sabah, Malaysia, there are still high probability of limited clean water access in rural area and disaster site. Few villages had been affected in Pitas due to improper road access, thus building a water treatment plant there might not be feasible. Recently, Kundasang area had been affected by earthquake that caused water disruption to its people due to the damage in the underground pipes and water tanks. It has been known that membrane technology brought ease in making mobile water treatment system that can be transported to rural or disaster area. In this study, hollow fiber membrane used in a mobile water treatment system due to compact and ease setup. Hollow fiber membrane was fabricated into small module at 15 and 30 fibers to suit the mobile water treatment system for potable water production of at least 80 L/day per operation. The effects of transmembrane pressure (TMP and feed water temperature were investigated. It was found that permeate flux increases by more than 96% for both 15 and 30 fiber bundles with increasing pressure in the range of 0.25 to 3.0 bar but dropped when the pressure reached maximum. Lower temperature of 17 to 18˚C increase the water viscosity by 15% from normal temperature of water at 24˚C, making the permeate flux decreases. The fabricated modules effectively removed 96% turbidity of the surface water sample tested.

  7. Progress in hollow core photonic crystal fiber for atomic vapour based coherent optics

    Science.gov (United States)

    Bradley, T. D.; Wang, Y. Y.; Alharbi, M.; Fourcade Dutin, C.; Mangan, B. J.; Wheeler, N. V.; Benabid, F.

    2012-03-01

    We report on progress in different hollow core photonic crystal fiber (HC-PCF) design and fabrication for atomic vapor based applications. We have fabricated a Photonic bandgap (PBG) guiding HC-PCF with a record loss of 107dB/km at 785nm in this class of fiber. A double photonic bandgap (DPBG) guiding HC-PCF with guidance bands centred at 780nm and 1064nm is reported. A 7-cell 3-ring Kagome HC-PCF with hypocycloid core is reported, the optical loss at 780nm has been reduced to 70dB/km which to the best of our knowledge is the lowest optical loss reported at this wavelength using HC-PCF. Details on experimental loading of alkali metal vapours using a far off red detuned laser are reported. This optical loading has been shown to decrease the necessary loading time for Rb into the hollow core of a fiber. The quantity of Rb within the fiber core has been enhanced by a maximum of 14% through this loading procedure.

  8. Use of the hollow fiber assay for the discovery of novel anticancer agents from fungi.

    Science.gov (United States)

    Pearce, Cedric J; Lantvit, Daniel D; Shen, Qi; Jarjoura, David; Zhang, Xiaoli; Oberlies, Nicholas H; Kroll, David J; Wani, Mansukh C; Orjala, Jimmy; Soejarto, Djaja D; Farnsworth, Norman R; de Blanco, Esperanza J Carcache; Fuchs, James R; Kinghorn, A Douglas; Swanson, Steven M

    2012-01-01

    The hollow fiber assay (HFA) is a drug discovery tool to aid investigators in the prioritization of lead compounds identified by in vitro testing for further development in animal models of disease. In the HFA, cells are cultured in hollow fibers containing pores of a diameter (500 kDa) large enough for proteins and other macromolecules to enter, but too small for the cells to escape. The fibers are filled with cells, sealed and placed in the peritoneal cavity of immunodeficient mice. The mice undergo a predetermined treatment regimen after which the fibers are retrieved and the cells evaluated for activity of a target relevant to the disease modeled. The HFA combines advantages of both in vitro and in vivo assay systems. It uses the same cell lines used in culture systems, is a rapid assay, and requires fewer animals and less test substance than conventional xenograft systems. Like traditional in vivo assays, the test substance is evaluated in a live animal, which affords an initial assessment of associated toxicity and pharmacokinetic properties of the test substance.

  9. Low loss mid-IR transmission bands using silica hollow-core anisotropic anti-resonant fibers

    DEFF Research Database (Denmark)

    Habib, Selim; Bang, Ole; Bache, Morten

    2016-01-01

    In this paper, a node-free anisotropic hollow-core anti-resonant fiber has been proposed to give low transmission loss in the near-IR to mid-IR spectral regime. The proposed silica-based fiber design shows transmission loss below 10 dB/km at 2.94 μm with multiple low loss transmission bands...

  10. Fabrication and formation mechanism of poly (L-lactic acid ultrafine multi-porous hollow fiber by electrospinning

    Directory of Open Access Journals (Sweden)

    Q. Z. Yu

    2013-01-01

    Full Text Available Poly(L-lactic acid (PLLA ultrafine multi-porous hollow fibers are fabricated by electrospinning with methylene dichloride as solvent. The Kirkendall effect has been widely applied for the fabrication of hollow structure in metals and inorganic materials. In this study, a conceptual extension is proposed for the formation mechanism: the development of porous hollow fiber undergoes three stages. The initial stage is the generation of small voids or pits on the surface of the fiber via surface diffusion and phase separation; the second stage is the formation of multi-pores penetrating the core of the fiber through the interaction of Kirkendall effect, surface diffusion and phase separation; the third stage is dominated by surface diffusion of the core material along the pore surface. To explore the formation conditions, the factors including ambient temperature, relativity humidity (R. H., molecular weight and fiber diameter are studied. The longitudinal and cross sectional morphologies of these fibers are examined by scanning electron micrograph (SEM. The results show that the prerequisite for the formation of uniform porous hollow PLLA fibers include moderate ambient temperature (10~20°C and appropriate molecular weight for the PLLA, as well as the diameter of the fiber in the range of several micrometers to about 100 nanometers.

  11. Demonstration of CO2-laser power delivery through chalcogenide-glass fiber with negative-curvature hollow core.

    Science.gov (United States)

    Kosolapov, Alexey F; Pryamikov, Andrey D; Biriukov, Alexander S; Shiryaev, Vladimir S; Astapovich, Maxim S; Snopatin, Gennady E; Plotnichenko, Victor G; Churbanov, Mikhail F; Dianov, Evgeny M

    2011-12-05

    A technologically simple optical fiber cross-section structure with a negative-curvature hollow-core has been proposed for the delivery of the CO2 laser radiation. The structure was optimized numerically and then realized using Te20As30Se50 (TAS) chalcogenide glass. Guidance of the 10.6 µm СО2-laser radiation through this TAS-glass hollow-core fiber has been demonstrated. The loss at λ=10.6 μm was amounted ~11 dB/m. A resonance behavior of the fiber bend loss as a function of the bend radius has been revealed.

  12. Outer-selective thin film composite (TFC) hollow fiber membranes for osmotic power generation

    KAUST Repository

    Le, Ngoc Lieu

    2016-01-14

    The pressure-retarded osmosis (PRO) process is a green technique for power generation to respond the world\\'s need of energy sustainability. In this study, we have developed the vital component of the process, i.e. membrane, in the configuration of the outer-selective thin-film composite (TFC) hollow fiber, which is more practical than other configurations in the real applications. The support layer morphology and the formation of the selective polyamide layer have been optimized for a good PRO performance. The results show that the bore fluid with higher amount of the solvent N-methyl-2-pyrrolidone leads to full finger-like hollow fibers, which provide higher flux but lower pressure tolerance. The addition of higher amount of diethylene glycol into the dope solution, improves the pore formation and suppresses the macrovoid formation, while properly lowering the take-up speed increases their wall thickness and pressure tolerance. A simple alcohol-pre-wetting approach on the fiber support leads to a smooth and thin polyamide layer, which is favorable for a high water flux and power density. Its efficiency follows this order: n-propanol>ethanol>methanol>water. The n-propanol pre-wetted TFC membrane can tolerate 17 bar with a peak power density of 9.59 W/m2 at room temperature, using 1 M NaCl solution as the draw solution and DI water as feed. This work demonstrates the potential of outer-selective TFC hollow fiber membranes for energy conversion via PRO process, provides useful database to fabricate suitable support morphology and raise a simple technique to practically form a thin and smooth polyamide layer.

  13. Ferrule and use thereof for cooling a melt spun hollow glass fiber as it emerges from a spinnerette

    Science.gov (United States)

    Brown, William E. (Inventor)

    1977-01-01

    An improvement in the process of melt spinning thin walled, hollow fibers from relatively low melting glasses results if cooling of the emerging fiber is accomplished by use of a thin layer of gas to transfer heat from the fiber to a ferrule which fits closely to the spinnerette face and the individual fiber. The ferrule incorporates or is in contact with a heat sink and is slotted or segmented so that it may be brought into position around the moving fiber. Thinner walled, more uniform fibers may be spun when this method of cooling is employed.

  14. Squeezed hollow-core photonic Bragg fiber for surface sensing applications.

    Science.gov (United States)

    Li, Jingwen; Qu, Hang; Skorobogatiy, Maksim

    2016-07-11

    We propose to use squeezed hollow-core photonic bandgap Bragg fibers for surface sensing applications. We demonstrate theoretically and confirm experimentally that squeezing a section of the Bragg fiber core increases overlap between the optical fields of the core guided modes and the modes bound to the sensing layer, thus, significantly enhancing their interaction via anticrossing phenomenon, which, in turn, enhances surface sensitivity of the fiber sensor. As a practical demonstration, we apply our fiber sensor to in situ monitoring of the dissolution dynamics of a sub-micron-thick polyvinyl butyral (PVB) film coated on the surface of the liquid-filled Bragg fiber core. Strong spectral shift is observed during the dissolution of the PVB film, and a surface spectral sensitivity of ~0.07nm/nm is achieved experimentally with aqueous analytes. The proposed fiber sensor offers a new sensing modality and opens new sensing applications for photonic bandgap fibers, such as real-time detection of binding and affinity, study of kinetics, etc. for a range of chemical and biological samples.

  15. Medical Application of Free Electron Laser Trasmittance using Hollow Optical Fiber

    CERN Document Server

    Suzuki, Sachiko; Ishii, Katsonuri

    2004-01-01

    Mid-infrared Free Electron Laser (FEL) is expected as new application for biomedical surgery. However, delivery of MIR-FEL into the body is difficult because the common glass optical fibers have strong absorption at MIR region. A good operational and flexible line for FEL is required at medical field. A Hollow optical fiber is developed for IR laser and high-power laser delivery. We evaluated the fiber for FEL transmission line. This fiber is coated with cyclic olefin polymer (COP) and silver thin film on the inside of glass capillary tube. It is 700 μm-bore and 1m in lengths. The fiber transmission loss of the measured wavelength region of 5.5 μm to 12 μm is less than 1dB/m when the fiber is straight and 1.2 dB/m when bent to radius of 20 cm. Additionally, the output beam profile and the pulse structure is not so different form incidence beam. In conclusion, the fiber is suitable for delivery of the FEL energy for applications in medical and laser surgery.

  16. Phase sensitivity of hollow-core photonic bandgap fiber to acoustic pressure

    Science.gov (United States)

    Pang, M.; Jin, W.

    2009-10-01

    Detection of acoustic pressure with optical fiber interferometers has been studied for many years1-3. The conventional solid silica fiber hydrophone was sufficient to prove the concept; however, it has low acoustic sensitivity. This is because 1) the silica glass material has relatively high Young's modulus, which makes the conventional fiber incompressible; 2) the refractive index change resulted from fiber strain has opposite sign with respective to the strain term and hence compromises the acoustic sensitivity. In a hollow-core photonic bandgap fiber (PBF), the fundamental mode is almost entirely confined to the air core, the effective Young's modulus of fiber is expected to be reduced and the undesirable "negative" index effect is anticipated to be greatly decreased. We experimentally measured that the phase sensitivity of the commercial HC-1550-02 PBF and found it is improved by a factor of 15dB compared to a conventional (HNSM-155) single mode fiber, which agrees well with theoretical prediction.

  17. Bandgaps of the Chalcogenide Glass Hollow-Core Photonic Crystal Fiber

    Science.gov (United States)

    Li, Shu-Guang; Zhou, Hong-Song; Yin, Guo-Bing

    2011-11-01

    Bandgaps of chalcogenide glass hollow-core photonic crystal fibers (GLS HC-PCFs) are analyzed by using the plane-wave expansion method. A mid-infrared laser can propagate in these low confinement loss fibers when the wavelength falls into the bandgaps. For enlarging the bandgap width, an improved GLS HC-PCF is put forward, the normalized frequency kΛ of the improved fiber is from 7.2 to 8.5 in its first bandgap. The improved GLS HC-PCF with pitch of 4.2 μm can transmit the lights with wavelengths ranging from 3.1 μm to 3.7 μm.

  18. Effect of Heat Transfer Coefficient on the Temperature Gradient for Hollow Fiber

    Institute of Scientific and Technical Information of China (English)

    王华平; 余晓蔚; 杨崇倡; 胡学超; 庄毅

    2001-01-01

    The heat transfer coefficient h caused by blowing affects the heat transfer of fiber greatly. Especially,unsymmetrical blowing forms the unsymmetrical temperature gradient on the fiber cross.section. Based on the results of spinning simulation by computer, the changes of heat transfer coefficient on the cross-section along the spinning line and the effects on distributions of temperature gradients were discussedl It is showed that for the spinning simulation of hollow fiber under strong blowing condition, the heat transfer coetticient should bemodified as: h=0.437×10-4[ G/Vρ ( R2/ R2-n2 ) ] -o.333(V2+ 64( VYsin (θ))2)0.167

  19. Photonic nanojet focusing for hollow-core photonic crystal fiber probes.

    Science.gov (United States)

    Ghenuche, Petru; Rigneault, Hervé; Wenger, Jérôme

    2012-12-20

    Large-pitch kagome-lattice hollow-core photonic crystal fibers (HC-PCFs) offer appealing optical properties for beam delivery and remote sensing. However, focusing their optical mode on a submicrometer spot can be challenging due to the large mode diameter and low numerical aperture of these fibers. Here, we demonstrate that a 30 μm latex microsphere directly set at the HC-PCF end-face provides an efficient means to focus the fiber mode down to a spot of 540 nm full width at half-maximum thanks to a photonic nanojet effect. The system is used for fluorescence imaging and direct laser writing on a thin absorbing layer. Potential applications include inspection of semiconductor wafers, photolithography, laser surgery, fluorescence sensing, or optical transfection.

  20. Differential high-resolution stimulated CW Raman spectroscopy of hydrogen in a hollow-core fiber

    CERN Document Server

    Westergaard, Philip G; Petersen, Jan C

    2015-01-01

    We demonstrate sensitive high-resolution stimulated Raman measurements of hydrogen using a hollow-core photonic crystal fiber (HC-PCF). The Raman transition is pumped by a narrow linewidth (<50 kHz) 1064 nm continuous-wave (CW) fiber laser. The probe light is produced by a homebuilt CW optical parametric oscillator (OPO), tunable from around 800 nm to 1300 nm (linewidth ~ 5 MHz). These narrow linewidth lasers allow for an excellent spectral resolution of approximately 10^-4 cm^(-1). The setup employs a differential measurement technique for noise rejection in the probe beam, which also eliminates background signals from the fiber. With the high sensitivity obtained, Raman signals were observed with only a few mW of optical power in both the pump and probe beams. This demonstration allows for high resolution Raman identification of molecules and quantification of Raman signal strengths.

  1. Self-formation of microporous polysulfone hollow fiber using a single nozzle spinneret and reduction of phase-inversion speed

    Science.gov (United States)

    Kim, Hyung Jin; Jang, Chang Sik; Kim, Byeong Hee; Seo, Young Ho

    2016-06-01

    This study proposed a simple fabrication technique for microporous hollow fibers whose inner channel was naturally formed because of a slow phase inversion speed. Conventionally, microporous hollow fibers have been fabricated by extruding a polymer solution through the outer nozzle and a bore liquid through the inner nozzle of a dual nozzle spinneret. Injecting a bore liquid played a key role for the formation of a hollow structure. In this study, the self-formation of a hollow structure of microporous fiber was developed using a single nozzle spinneret without a bore liquid. A sharp tip single nozzle spinneret of 200 µm in diameter was fabricated by the wetting effect of a liquid pre-polymer of polydimethylsiloxane, and polysulfone solution was extruded through the prepared single nozzle spinneret. The temperature of the coagulant bath was controlled in order to reduce the speed of phase change, because the phase-change speed depended on the temperature of the coagulant solution. An inner channel in the microporous fiber was successfully fabricated by reducing the phase-change speed and by increasing the solidification speed. The inner diameter of the microporous hollow fiber was decreased as the temperature of the coagulant bath was increased, and eventually the inner channel was not formed at the higher bath temperature rather than 25 °C.

  2. Influence of nano-fiber membranes on the silver ions released from hollow fibers containing silver particles

    Directory of Open Access Journals (Sweden)

    Li Huigai

    2016-01-01

    Full Text Available Polyether sulfone was dissolved into dimethylacetamide with the concentration of 20% to prepare a uniform solution for fabrication of nanofiber membranes by bubble electrospinning technique. Morphologies of the nanofiber film were carried out with a scanning electron microscope. The influence on the silver ions escaped from hollow fiber loaded with silver particles was exerted by using different release liquid. The water molecular clusters obtained from the nanofiber membranes filter can slow down the release of silver ions. However, the effect of slowing was weakened with the time increasing. In the end, the trend of change is gradually consistent with the trend of release of silver ions in the deionized water.

  3. Anisotropic anti-resonant elements gives broadband single-mode low-loss hollow-core fibers

    DEFF Research Database (Denmark)

    Habib, Selim; Bang, Ole; Bache, Morten

    2016-01-01

    Hollow-core fibers with node-free anisotropic anti-resonant elements give broadband low-loss fibers that are also single-moded. At 1.06 μm silica-based fiber designs show higher-order-mode extinction-ratio >1000 and losses below 10 dB/km over a broad wavelength range.......Hollow-core fibers with node-free anisotropic anti-resonant elements give broadband low-loss fibers that are also single-moded. At 1.06 μm silica-based fiber designs show higher-order-mode extinction-ratio >1000 and losses below 10 dB/km over a broad wavelength range....

  4. Morphological architecture of dual-layer hollow fiber for membrane distillation with higher desalination performance.

    Science.gov (United States)

    Wang, Peng; Teoh, May May; Chung, Tai-Shung

    2011-11-01

    A new strategy to enhance the desalination performance of polyvinylidene fluoride (PVDF) hollow fiber membrane for membrane distillation (MD) via architecture of morphological characteristics is explored in this study. It is proposed that a dual-layer hollow fiber consisting of a fully finger-like macrovoid inner-layer and a sponge-like outer-layer may effectively enhance the permeation flux while maintaining the wetting resistance. Dual-layer fibers with the proposed morphology have been fabricated by the dry-jet wet spinning process via careful choice of dopes composition and coagulation conditions. In addition to high energy efficiency (EE) of 94%, a superior flux of 98.6 L m(-2) h(-1) is obtained during the direct contact membrane distillation (DCMD) desalination experiments. Moreover, the liquid entry pressure (LEP) and long-term DCMD performance test show high wetting resistance and long-term stability. Mathematical modeling has been conducted to investigate the membrane mass transfer properties in terms of temperature profile and apparent diffusivity of the membranes. It is concluded that the enhancement in permeation flux arises from the coupling effect of two mechanisms; namely, a higher driving force and a lower mass transfer resistance, while the later is the major contribution. This work provides an insight on MD fundamentals and strategy to tailor making ideal membranes for DCMD application in desalination industry. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Fabrication of polystyrene fibers with tunable co-axial hollow tubing structure for oil spill cleanup

    Science.gov (United States)

    Zhang, Minxin; Chen, Jiafu; Chen, Bingjing; Cao, Jingjing; Hong, Min; Zhou, Chenxu; Xu, Qun

    2016-03-01

    Hollow tubing polystyrene (PS) fibers (HFs) with porous shell were successfully fabricated through co-axial electrospinning and selectively dissolving and removing polyvinyl pyrrolidone (PVP) core of the co-axial PS/PVP fibers using C2H5OH at room temperature. The size of co-axial hollow tubing structure (CHTS) and the thickness of shell can be controlled by varying the feed rate ratio of the core solution to the shell solution. The oil-sorption results show that the oil-sorption capacity increases with the increasing of the size of CHTS in the HFs, and the HFs have higher oil-sorption capacities than the porous PS fibers (PFs) without CHTS. It is noticeable that the diesel sorption capacity (66 g/g) of the HFs is approximately 1.74 times as much as that (38 g/g) of the PFs. The motor oil sorption capacity (147 g/g) of the HFs is approximately 1.55 times as much as that (95 g/g) of the PFs. It is suggested that the HFs have a better oil-sorption performance than the PFs, especially for the low viscosity oil, which is contributed to large CHTS and high porosity.

  6. A theoretical model for evaluation of the design of a hollow-fiber membrane oxygenator.

    Science.gov (United States)

    Tabesh, Hadi; Amoabediny, Ghassem; Poorkhalil, Ali; Khachab, Ali; Kashefi, Ali; Mottaghy, Khosrow

    2012-12-01

    Geometric data are fundamental to the design of a contactor. The efficiency of a membrane contactor is mainly defined by its mass-transfer coefficient. However, design modifications also have significant effects on the performance of membrane contactors. In a hollow-fiber membrane oxygenator (HFMO), properties such as priming volume and effective membrane surface area (referred to as design specifications) can be determined. In this study, an extensive theoretical model for calculation of geometric data and configuration properties, and, consequently, optimization of the design of an HFMO, is presented. Calculations were performed for Oxyphan(®) hollow-fiber micro-porous membranes, which are frequently used in current HFMOs because of their high gas exchange performance. The results reveal how to regulate both the transverse and longitudinal pitches of fiber bundles to obtain a lower rand width and a greater number of windings. Such modifications assist optimization of module design and, consequently, substantially increase the efficiency of an HFMO. On the basis of these considerations, three values, called efficiency factors, are proposed for evaluation of the design specifications of an HFMO with regard with its performance characteristics (i.e. oxygen-transfer rate and blood pressure drop). Moreover, the performance characteristics of six different commercial HFMOs were measured experimentally, in vitro, under the same standard conditions. Comparison of calculated efficiency factors reveals Quadrox(®) is the oxygenator with the most efficient design with regard with its performance among the oxygenators tested.

  7. Hollow-Fiber Cartridges: Model Systems for Virus Removal from Blood

    Science.gov (United States)

    Jacobitz, Frank; Menon, Jeevan

    2005-11-01

    Aethlon Medical is developing a hollow-fiber hemodialysis device designed to remove viruses and toxins from blood. Possible target viruses include HIV and pox-viruses. The filter could reduce virus and viral toxin concentration in the patient's blood, delaying illness so the patient's immune system can fight off the virus. In order to optimize the design of such a filter, the fluid mechanics of the device is both modeled analytically and investigated experimentally. The flow configuration of the proposed device is that of Starling flow. Polysulfone hollow-fiber dialysis cartridges were used. The cartridges are charged with water as a model fluid for blood and fluorescent latex beads are used in the experiments as a model for viruses. In the experiments, properties of the flow through the cartridge are determined through pressure and volume flow rate measurements of water. The removal of latex beads, which are captured in the porous walls of the fibers, was measured spectrophotometrically. Experimentally derived coefficients derived from these experiments are used in the analytical model of the flow and removal predictions from the model are compared to those obtained from the experiments.

  8. Tri-bore PVDF hollow fibers with a super-hydrophobic coating for membrane distillation

    KAUST Repository

    Lu, Kang-Jia

    2016-04-26

    Membranes with good mechanical strength, high vapor flux and outstanding anti-wetting properties are essential for membrane distillation (MD) applications. In this work, porous polyvinylidene fluoride (PVDF) tri-bore hollow fiber membranes with super-hydrophobicity are developed to achieve these desired properties. The tri-bore hollow fiber offers better mechanical strength than the conventional single-bore fiber. To improve its anti-wetting properties, Teflon® AF 2400 is coated on the membrane surface. The effects of coating on membrane morphology, performance and anti-wetting properties have been thoroughly investigated. With an optimal coating condition (0.025 wt% of Teflon® AF 2400, 30 s), a super-hydrophobic surface with a contact angle of 151o is achieved. The resultant membrane shows an increase of 109% in liquid entry pressure (LEP) with a slight sacrifice of 21% in flux. Long term direct contact MD tests have confirmed that the Teflon® AF 2400 coated membrane has enhanced stability with an average flux of 21 kg m-2 h-1 and rejection of 99.99% at 60 °° C for desalination application.

  9. Supramolecular solvent-based hollow fiber liquid phase microextraction of benzodiazepines.

    Science.gov (United States)

    Rezaei, Fatemeh; Yamini, Yadollah; Moradi, Morteza; Daraei, Bahram

    2013-12-04

    A new, efficient, and environmental friendly hollow fiber liquid phase microextraction (HF-LPME) method based on supramolecular solvents was developed for extraction of five benzodiazepine drugs. The supramolecular solvent was produced from coacervation of decanoic acid aqueous vesicles in the presence of tetrabutylammonium (Bu4N(+)). In this work, benzodiazepines were extracted from aqueous samples into a supramolecular solvent impregnated in the wall pores and also filled inside the porous polypropylene hollow fiber membrane. The driving forces for the extraction were hydrophobic, hydrogen bonding, and π-cation interactions between the analytes and the vesicular aggregates. High-performance liquid chromatography with photodiode array detection (HPLC-DAD) was applied for separation and determination of the drugs. Several parameters affecting the extraction efficiency including pH, hollow fiber length, ionic strength, stirring rate, and extraction time were investigated and optimized. Under the optimal conditions, the preconcentration factors were obtained in the range of 112-198. Linearity of the method was determined to be in the range of 1.0-200.0 μg L(-1) for diazepam and 2.0-200.0 μg L(-1) for other analytes with coefficient of determination (R(2)) ranging from 0.9954 to 0.9993. The limits of detection for the target benzodiazepines were in the range of 0.5-0.7 μg L(-1). The method was successfully applied for extraction and determination of the drugs in water, fruit juice, plasma and urine samples and relative recoveries of the compounds studied were in the range of 90.0-98.8%.

  10. X-ray beam transfer between hollow fibers for long-distance transport

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Yoshihito, E-mail: tanaka@sci.u-hyogo.ac.jp; Matsushita, Ryuki; Shiraishi, Ryutaro; Hasegawa, Takayuki; Ishikawa, Kiyoshi [Graduate School of Material Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Sayo-gun, Hyogo 678-1297 (Japan); Sawada, Kei; Kohmura, Yoshiki [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Takahashi, Isao [Department of Physics, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 Japan (Japan)

    2016-07-27

    Fiber optics for controlling the x-ray beam trajectory has been examined at the synchrotron facility of SPring-8. Up to now, we have achieved beam deflection by several tens of milli-radian and axis shift of around 75 mm with a 1.5 m-long flexible hollow glass capillary. The achievable beam deflecting angle, axis shift, and timing delay are, in principle, proportional to the length, the square of length and the cube of length, respectively. Thus, for further applications, requiring larger beam shift and pulse delay, longer fibers are indispensable. In order to achieve long-distance transport using the fiber, we thus examined the connection transferring x-rays between fibers in an experimental hutch. The acceptance angle at the input end and the throughput efficiency of the second fiber is consistent with the consideration of the output beam divergence of the first fiber. The enhancement of the transfer efficiency is also discussed for the cases of a closer joint and the use of a refractive lens as a coupler.

  11. Molecular Spectroscopy in Hollow-Core Photonic Crystal Fiber at the 10 kHz Level

    Science.gov (United States)

    Wang, Chenchen; Knabe, Kevin; Wu, Shun; Lim, Jinkang; Tillman, Karl; Washburn, Brian; Corwin, Kristan; Wheeler, Natalie; Couny, Francois; Benabid, Fetah

    2010-03-01

    High-accuracy spectroscopy in hollow-core photonic crystal fiber (HC-PCF) is desirable for many applications, including frequency references and trace gas analysis. We demonstrate the narrowest sub-Doppler linewidths attained in HC-PCF using large-core kagome structured fiber. Such fibers can yield highly accurate frequency measurements that are about two orders of magnitude higher than previously reported. A fiber laser is locked to the ^12C2H2 ν1+ν3 P(13) transition inside kagome fiber, and compared with two optical frequency combs referenced to a GPS-disciplined Rb oscillator. The absolute frequency of the measured line center agrees with those measured in power build-up cavities to within 9.3 kHz (1 σ error). Approaches to further narrow the linewidths and improve systematic errors are investigated. The present system thus combines accuracy approaching that of power build-up cavities with the potential to be compact, robust, and integrated into an all-fiber system for a portable near-infrared frequency reference. Supported by AFOSR FA9950-05-1-0304 and NSF ECS-0449295.

  12. Effect of Polyvinylidene Fluoride Hollow Fiber Membranes on Mass Transfer of Samarium

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The influence of swelling and stripping acidity on the mass transfer coefficient based on water phase and the inner diameters of membranes were studied with P507-HCl-Sm as working system in the two different kinds of hollow fiber membranes. Effects of extractant concentration, H+ concentration in aqueous phase and Sm3+ concentration on extraction rate were discussed and the corresponding reaction series were obtained. According to the investigations on the interfacial kinetics, the reaction kinetics equation and reaction rate constant were obtained.

  13. Continuous generation of Rubidium vapor in hollow-core photonic band-gap fibers

    CERN Document Server

    Donvalkar, Prathamesh S; Clemmen, Stephane; Gaeta, Alexander L

    2015-01-01

    We demonstrate high optical depths (50+/-5), lasting for hours in Rubidium-filled hollow-core photonic band-gap fibers, which represents a 1000X improvement over operation times previously reported. We investigate the vapor generation mechanism using both a continuous-wave and a pulsed light source and find that the mechanism for generating the Rubidium atoms is primarily due to thermal vaporization. Continuous generation of large vapor densities should enable measurements at the single-photon level by averaging over longer time scales.

  14. Soliton-plasma nonlinear dynamics in mid-IR gas-filled hollow-core fibers

    DEFF Research Database (Denmark)

    Habib, Selim; Markos, Christos; Bang, Ole

    2017-01-01

    We investigate numerically soliton-plasma interaction in a noble-gas-filled silica hollow-core anti-resonant fiber pumped in the mid-IR at 3.0 mu m. We observe multiple soliton self-compression stages due to distinct stages where either the self-focusing or the self-defocusing nonlinearity...... dominates. Specifically, the parameters may be tuned so the competing plasma self-defocusing nonlinearity only dominates over the Kerr self-focusing nonlinearity around the soliton self-compression stage, where the increasing peak intensity on the leading pulse edge initiates a competing self...

  15. Estimating needle-tissue interaction forces for hollow needles using fiber Bragg grating sensors

    Science.gov (United States)

    Kumar, Saurabh; Shrikanth, V.; Bharadwaj, Amrutur; Asokan, Sundarrajan; Bobji, M. S.

    2016-03-01

    Brachytherapy and neurological procedures can benefit from real-time estimation of needle-tissue interaction forces, specifically for robotic or robot-assisted procedures. Fiber Bragg Grating Sensors provide advantages of very small size and electromagnetic immunity for use in measurement of the forces directly at the needle tip. This has advantages compared to measurements at the needle shaft which require extensive models of the friction between needle and tissues with varying depth. This paper presents the measurement of tip forces for a hollow needle and compensation for bending when encountering regions of varying stiffness in phantoms with multiple layers prepared using Polydimethylsiloxane.

  16. Low-Loss Hollow Waveguide Fibers for Mid-Infrared Quantum Cascade Laser Sensing Applications

    Directory of Open Access Journals (Sweden)

    James A. Harrington

    2013-01-01

    Full Text Available We report on single mode optical transmission of hollow core glass waveguides (HWG coupled with an external cavity mid-IR quantum cascade lasers (QCLs. The QCL mode results perfectly matched to the hybrid HE11 waveguide mode and the higher losses TE-like modes have efficiently suppressed by the deposited inner dielectric coating. Optical losses down to 0.44 dB/m and output beam divergence of ~5 mrad were measured. Using a HGW fiber with internal core size of 300 µm we obtained single mode laser transmission at 10.54 µm and successful employed it in a quartz enhanced photoacoustic gas sensor setup.

  17. Dynamics of blueshifted floating pulses in gas filled hollow-core photonic crystal fibers

    CERN Document Server

    Facao, M

    2013-01-01

    Frequency blueshifting was recently observed in light pulses propagating on gas filled hollow-core photonic crystal fibers where a plasma has been produced due to photoionization of the gas. One of the propagation models that is adequate to describe the actual experimental observations is here investigated. It is a nonlinear Schr\\"odinger equation with an extra term, to which we applied a self-similar change of variables and found its accelerating solitons. As in other NLS related models possessing accelerating solitons, there exist asymmetrical pulses that decay as they propagate in some parameter region that was here well defined.

  18. Low-loss hollow waveguide fibers for mid-infrared quantum cascade laser sensing applications.

    Science.gov (United States)

    Patimisco, Pietro; Spagnolo, Vincenzo; Vitiello, Miriam S; Scamarcio, Gaetano; Bledt, Carlos M; Harrington, James A

    2013-01-21

    We report on single mode optical transmission of hollow core glass waveguides (HWG) coupled with an external cavity mid-IR quantum cascade lasers (QCLs). The QCL mode results perfectly matched to the hybrid HE(11) waveguide mode and the higher losses TE-like modes have efficiently suppressed by the deposited inner dielectric coating. Optical losses down to 0.44 dB/m and output beam divergence of ~5 mrad were measured. Using a HGW fiber with internal core size of 300 µm we obtained single mode laser transmission at 10.54 µm and successful employed it in a quartz enhanced photoacoustic gas sensor setup.

  19. Dispersion-controlled hollow core fiber for phase matched harmonic generation.

    Science.gov (United States)

    Christov, I; Kapteyn, H; Murnane, M

    1998-11-09

    We describe theoretically the performance of a new design for quasi-phase matched harmonic generation in a gas medium. A hollow core fiber in which thick glass plates are periodically introduced allows good phase control of the fundamental light. The generated x-rays are transmitted throught small holes in the plates. An increase of the harmonic yield of up to three orders of magnitude is predicted as a result of the structure. This esign can be considered as a phase-locked travelling-wave x-ray laser.

  20. Raman imaging of carious lesions using a hollow optical fiber probe.

    Science.gov (United States)

    Yokoyama, Eriko; Kakino, Satoko; Matsuura, Yuji

    2008-08-10

    Raman spectroscopy using a hollow optical fiber probe with a glass ball lens at the distal end is proposed for detection of early caries lesions. Raman spectroscopy on carious lesions of extracted teeth showed that the probe enables measurement with a high signal-to-noise ratio when combined with a ball lens with a high refractive index. The proposed probe and lens combination detects changes in Raman spectra caused by morphological differences between sound and carious enamel. We also obtained a high-contrast image of an early carious lesion by scanning the tooth surface with the probe.

  1. Experimental study on generation of high energy few cycle pulses with hollow fiber filled with neon

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    25 fs pulses with energy up to 0.8 mJ from a multi-pass amplifier system have been spectrally broadened from 460 nm to 950 nm due to strong self-phase modulation(SPM) effect in a gas filled hollow fiber.Using a set of chirped mirrors,the ul-tra-broadband dispersion compensation was achieved,and the compressed pulses reached their transform limit.Under optimized conditions we achieved pulses with duration of 5.1 fs and with energy of 400 μJ,corresponding to the peak power up to 80 GW.

  2. Experimental study on generation of high energy few cycle pulses with hollow fiber filled with neon

    Institute of Scientific and Technical Information of China (English)

    ZHU JiangFeng; WANG Peng; HAN HaiNian; TENG Hao; WEI ZhiYi

    2008-01-01

    25 fs pulses with energy up to 0.8 mJ from a multi-pass amplifier system have been spectrally broadened from 460 nm to 950 nm due to strong self-phase modulation (SPM) effect in a gas filled hollow fiber. Using a set of chirped mirrors, the ul-tra-broadband dispersion compensation was achieved, and the compressed pulses reached their transform limit. Under optimized conditions we achieved pulses with duration of 5.1 fs and with energy of 400 μJ, corresponding to the peak power up to 80 GW.

  3. Hollow-core photonic bandgap fiber gas sensor with high sensitivity and fast response

    Science.gov (United States)

    Yang, Fan; Jin, Wei; Cao, Yingchun; Ho, Hoi Lut

    2014-05-01

    The effects of modal interference (MI) on the performance of hollow-core photonic bandgap fiber (HC-PBF) gas sensors are investigated. By optimizing mode launch, applying wavelength modulation with proper modulation parameters as well as appropriate digital signal processing, an estimated lower detection limit of drilling side-hole on the MI and response time are also studied. With a 62-cm long sensing HC-PBF drilled with multiple side-holes, an acetylene sensor with a lower detection limit of 11 ppmv and a recovery time of 2 minute is demonstrated.

  4. Darcy permeability of hollow fiber membrane bundles made from Membrana® Polymethylpentene (PMP) fibers used in respiratory assist devices

    Science.gov (United States)

    Madhani, Shalv. P.; D’Aloiso, Brandon. D.; Frankowski, Brian.; Federspiel, William. J.

    2016-01-01

    Hollow fiber membranes (HFMs) are used in blood oxygenators for cardiopulmonary bypass or in next generation artificial lungs. Flow analyses of these devices is typically done using computational fluid dynamics (CFD) modeling HFM bundles as porous media, using a Darcy permeability coefficient estimated from the Blake – Kozeny (BK) equation to account for viscous drag from fibers. We recently published how well this approach can predict Darcy permeability for fiber bundles made from polypropylene HFMs, showing the prediction can be significantly improved using an experimentally derived correlation between the BK constant (A) and bundle porosity (ε). In this study, we assessed how well our correlation for A worked for predicting the Darcy permeability of fiber bundles made from Membrana® polymethylpentene (PMP) HFMs, which are increasingly being used clinically. Swatches in the porosity range of 0.4 to 0.8 were assessed in which sheets of fiber were stacked in parallel, perpendicular and angled configurations. Our previously published correlation predicted Darcy within ±8%. A new correlation based on current and past measured permeability was determined: A=497ε-103; using this correlation measured Darcy permeability was within ±6%. This correlation varied from 8% to −3.5% of our prior correlation over the tested porosity range. PMID:26809086

  5. Darcy Permeability of Hollow Fiber Membrane Bundles Made from Membrana Polymethylpentene Fibers Used in Respiratory Assist Devices.

    Science.gov (United States)

    Madhani, Shalv P; D'Aloiso, Brandon D; Frankowski, Brian; Federspiel, William J

    2016-01-01

    Hollow fiber membranes (HFMs) are used in blood oxygenators for cardiopulmonary bypass or in next generation artificial lungs. Flow analyses of these devices is typically done using computational fluid dynamics (CFD) modeling HFM bundles as porous media, using a Darcy permeability coefficient estimated from the Blake-Kozeny (BK) equation to account for viscous drag from fibers. We recently published how well this approach can predict Darcy permeability for fiber bundles made from polypropylene HFMs, showing the prediction can be significantly improved using an experimentally derived correlation between the BK constant (A) and bundle porosity (ε). In this study, we assessed how well our correlation for A worked for predicting the Darcy permeability of fiber bundles made from Membrana polymethylpentene (PMP) HFMs, which are increasingly being used clinically. Swatches in the porosity range of 0.4 to 0.8 were assessed in which sheets of fiber were stacked in parallel, perpendicular, and angled configurations. Our previously published correlation predicted Darcy within ±8%. A new correlation based on current and past measured permeability was determined: A = 497ε - 103; using this correlation measured Darcy permeability was within ±6%. This correlation varied from 8% to -3.5% of our prior correlation over the tested porosity range.

  6. Poly(ethyleneimine) infused and functionalized Torlon®-silica hollow fiber sorbents for post-combustion CO2 capture

    KAUST Repository

    Li, Fuyue Stephanie

    2014-03-01

    Organic-inorganic hybrid materials functionalized with amine-containing reagents are emerging as an important class of materials for capturing carbon dioxide from flue gas. Polymeric silica hollow fiber sorbents are fabricated through the proven dry-jet/wet-quench spinning process. In our study, a new technique for functionalizing polymeric silica hollow fiber sorbents with poly(ethyleneimine), followed by a post-spinning infusion step was studied. This two step process introduces a sufficient amount of poly(ethyleneimine) to the polymeric silica hybrid material support to improve the CO2 sorption capacity due to the added amine groups. The poly(ethyleneimine) infused and functionalized hollow fiber sorbents are also characterized by a thermal gravimetric analyzer (TGA) to assess their CO2 sorption capacities. © 2014 Elsevier Ltd. All rights reserved.

  7. One-Step Synthesis of Hollow Titanate (Sr/Ba) Ceramic Fibers for Detoxification of Nerve Agents

    OpenAIRE

    2012-01-01

    Poly(vinyl pyrrolidone)(PVP)/(strontium/barium acetate)/titanium isopropoxide composite fibers were prepared by electrospinning technique via sol-gel process. Diameters of fibers prepared by calcinations of PVP composite fibers were 80–140 nm (solid) and 1.2-2.2 μm (hollow fibers prepared by core-shell method). These fibers were characterized using scanning electron microscope (SEM), X-ray diffraction (XRD), and transmission electron microscope (TEM) analytical techniques. XRD results showed ...

  8. Wet spinning of integrally skinned hollow fiber membranes by a modified dual-bath coagulation method using a triple orifice spinneret

    NARCIS (Netherlands)

    Li, S.-G.; Koops, G.H.; Mulder, M.H.V.; Boomgaard, van den A.; Smolders, C.A.

    1994-01-01

    Three main routes are known to prepare hollow fiber membranes; melt spinning, dry spinning and wet spinning (or dry/wet spinning). The latter is the most important technique for the preparation of industrial hollow fiber membranes. In this process the extruded polymer solution is immersed in a nonso

  9. Wet spinning of integrally skinned hollow fiber membranes by a modified dual-bath coagulation method using a triple orifice spinneret

    NARCIS (Netherlands)

    Li, S.G.; Li, S.-G.; Koops, G.H.; Mulder, M.H.V.; van den Boomgaard, Anthonie; Smolders, C.A.; Smolders, C.A.

    1994-01-01

    Three main routes are known to prepare hollow fiber membranes; melt spinning, dry spinning and wet spinning (or dry/wet spinning). The latter is the most important technique for the preparation of industrial hollow fiber membranes. In this process the extruded polymer solution is immersed in a nonso

  10. Fiber Attachment Module Experiment (FAME): Using a Multiplexed Miniature Hollow Fiber Membrane Bioreactor Solution for Rapid Process Testing

    Science.gov (United States)

    Lunn, Griffin; Wheeler, Raymond; Hummerick, Mary; Birmele, Michele; Richards, Jeffrey; Coutts, Janelle; Koss, Lawrence; Spencer, Lashelle.; Johnsey, Marissa; Ellis, Ronald

    Bioreactor research, even today, is mostly limited to continuous stirred-tank reactors (CSTRs). These are not an option for microgravity applications due to the lack of a gravity gradient to drive aeration as described by the Archimedes principle. This has led to testing of Hollow Fiber Membrane Bioreactors (HFMBs) for microgravity applications, including possible use for wastewater treatment systems for the International Space Station (ISS). Bioreactors and filtration systems for treating wastewater could avoid the need for harsh pretreatment chemicals and improve overall water recovery. However, the construction of these reactors is difficult and commercial off-the-shelf (COTS) versions do not exist in small sizes. We have used 1-L modular HFMBs in the past, but the need to perform rapid testing has led us to consider even smaller systems. To address this, we designed and built 125-mL, rectangular reactors, which we have called the Fiber Attachment Module Experiment (FAME) system. A polycarbonate rack of four square modules was developed with each module containing removable hollow fibers. Each FAME reactor is self-contained and can be easily plumbed with peristaltic and syringe pumps for continuous recycling of fluids and feeding, as well as fitted with sensors for monitoring pH, dissolved oxygen, and gas measurements similar to their larger counterparts. The first application tested in the FAME racks allowed analysis of over a dozen fiber surface treatments and three inoculation sources to achieve rapid reactor startup and biofilm attachment (based on carbon oxidation and nitrification of wastewater). With these miniature FAME reactors, data for this multi-factorial test were collected in duplicate over a six-month period; this greatly compressed time period required for gathering data needed to study and improve bioreactor performance.

  11. Wet air oxidation of formic acid using nanoparticle-modified polysulfone hollow fibers as gas-liquid contactors.

    Science.gov (United States)

    Hogg, Seth R; Muthu, Satish; O'Callaghan, Michael; Lahitte, Jean-Francois; Bruening, Merlin L

    2012-03-01

    Catalytic wet air oxidation (CWAO) using membrane contactors is attractive for remediation of aqueous pollutants, but previous studies of even simple reactions such as formic acid oxidation required multiple passes through tubular ceramic membrane contactors to achieve high conversion. This work aims to increase single-pass CWAO conversions by using polysulfone (PS) hollow fibers as contactors to reduce diffusion distances in the fiber lumen. Alternating adsorption of polycations and citrate-stabilized platinum colloids in fiber walls provides catalytically active PS hollow fibers. Using a single PS fiber, 50% oxidation of a 50 mM formic acid feed solution results from a single pass through the fiber lumen (15 cm length) with a solution residence time of 40 s. Increasing the number of PS fibers to five while maintaining the same volumetric flow rate leads to over 90% oxidation, suggesting that further scale up in the number of fibers will facilitate high single pass conversions at increased flow rates. The high conversion compared to prior studies with ceramic fibers stems from shorter diffusion distances in the fiber lumen. However, the activity of the Pt catalyst is 20-fold lower than in previous ceramic fibers. Focusing the Pt deposition near the fiber lumen and limiting pore wetting to this region might increase the activity of the catalyst.

  12. Two-Mode Multiplexing at 2×10.7 Gbps over 7-Cell Hollow- Core Photonic Band Gap Fiber

    DEFF Research Database (Denmark)

    Xu, Jing; Peucheret, Christophe

    2011-01-01

    We demonstrate two-mode multiplexing at 2×10.7 Gbps over 7-cell hollow-core photonic band gap fiber. BER performances below FEC threshold limit (3.3×10-3) are shown for both data channels.......We demonstrate two-mode multiplexing at 2×10.7 Gbps over 7-cell hollow-core photonic band gap fiber. BER performances below FEC threshold limit (3.3×10-3) are shown for both data channels....

  13. GMP-Compliant Expansion of Clinical-Grade Human Mesenchymal Stromal/Stem Cells Using a Closed Hollow Fiber Bioreactor.

    Science.gov (United States)

    Barckhausen, Christina; Rice, Brent; Baila, Stefano; Sensebé, Luc; Schrezenmeier, Hubert; Nold, Philipp; Hackstein, Holger; Rojewski, Markus Thomas

    2016-01-01

    This chapter describes a method for GMP-compliant expansion of human mesenchymal stromal/stem cells (hMSC) from bone marrow aspirates, using the Quantum(®) Cell Expansion System from Terumo BCT. The Quantum system is a functionally closed, automated hollow fiber bioreactor system designed to reproducibly grow cells in either GMP or research laboratory environments. The chapter includes protocols for preparation of media, setup of the Quantum system, coating of the hollow fiber bioreactor, as well as loading, feeding, and harvesting of cells. We suggest a panel of quality controls for the starting material, the interim product, as well as the final product.

  14. A Pilot-Scale System for Carbon Molecular Sieve Hollow Fiber Membrane Manufacturing

    KAUST Repository

    Karvan, O.

    2012-12-21

    Carbon molecular sieve (CMS) membranes offer advantages over traditional polymeric membrane materials, but scale-up of manufacturing systems has not received much attention. In the recent decade, there has been a dramatic increase in fundamental research on these materials with a variety of applications being studied. The results from a pilot-scale CMS production system are presented. This system was designed based on extensive laboratory research, and hollow fiber membranes produced in this system show similar performance compared to membranes produced using a smaller bench-scale system. After optimizing the system design, a 93% recovery of the precursor fibers for use in membrane module preparation were obtained. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Symbiotic hollow fiber membrane photobioreactor for microalgal growth and bacterial wastewater treatment.

    Science.gov (United States)

    Vu, Linh T K; Loh, Kai-Chee

    2016-11-01

    A hollow fiber membrane photobioreactor (HFMP) for microalgal growth and bacterial wastewater treatment was developed. C. vulgaris culture was circulated through one side of the HFMP and P. putida culture was circulated through the other. A symbiotic relationship was demonstrated as reflected by the photo-autotrophic growth of C. vulgaris using CO2 provided by P. putida and biodegradation of 500mg/L glucose by P. putida utilizing photosynthetic O2 produced by C. vulgaris. Performance of the HFMP was significantly enhanced when the microalgal culture was circulated through the lumen side of the HFMP: the average percentage of glucose degraded per 8-h cycle was as high as 98% and microalgal biomass productivity was increased by 69% compared to the reversed orientation. Enhanced glucose biodegradation was achieved in an HFMP packed with more fibers indicating the easy scalability of the HFMP for increased wastewater treatment efficiency.

  16. Atomic mercury vapor inside a hollow-core photonic crystal fiber

    CERN Document Server

    Vogl, Ulrich; Joly, Nicolas Y; Russell, Philip St J; Marquardt, Christoph; Leuchs, Gerd

    2014-01-01

    We demonstrate high atomic mercury vapor pressure in a kagom\\'e-style hollow-core photonic crystal fiber at room temperature. After a few days of exposure to mercury vapor the fiber is homogeneously filled and the optical depth achieved remains constant. With incoherent optical pumping from the ground state we achieve an optical depth of 114 at the $6^3P_2 - 6^3D_3$ transition, corresponding to an atomic mercury number density of $6 \\times 10^{10}$ cm$^{-3}$. The use of mercury vapor in quasi one-dimensional confinement may be advantageous compared to chemically more active alkali vapor, while offering strong optical nonlinearities in the ultraviolet region of the optical spectrum.

  17. Identification of Bloch-modes in hollow-core photonic crystal fiber cladding.

    Science.gov (United States)

    Couny, F; Benabid, F; Roberts, P J; Burnett, M T; Maier, S A

    2007-01-22

    We report on the experimental visualization of the cladding Bloch-modes of a hollow-core photonic crystal fiber. Both spectral and spatial field nformation is extracted using the approach, which is based on measurement of the near-field and Fresnel-zone that results after propagation over a short length of fiber. A detailed study of the modes near the edges of the band gap shows that it is formed by the influence of three types of resonator: the glass interstitial apex, the silica strut which joins the neighboring apexes, and the air hole. The cladding electromagnetic field which survives the propagation is found to be spatially coherent and to contain contributions from just a few types of cladding mode.

  18. Optofluidic refractive-index sensor in step-index fiber with parallel hollow micro-channel.

    Science.gov (United States)

    Lee, H W; Schmidt, M A; Uebel, P; Tyagi, H; Joly, N Y; Scharrer, M; Russell, P St J

    2011-04-25

    We present a simple refractive index sensor based on a step-index fiber with a hollow micro-channel running parallel to its core. This channel becomes waveguiding when filled with a liquid of index greater than silica, causing sharp dips to appear in the transmission spectrum at wavelengths where the glass-core mode phase-matches to a mode of the liquid-core. The sensitivity of the dip-wavelengths to changes in liquid refractive index is quantified and the results used to study the dynamic flow characteristics of fluids in narrow channels. Potential applications of this fiber microstructure include measuring the optical properties of liquids, refractive index sensing, biophotonics and studies of fluid dynamics on the nanoscale.

  19. Design of low-loss and highly birefringent hollow-core photonic crystal fiber

    Science.gov (United States)

    Roberts, P. J.; Williams, D. P.; Sabert, H.; Mangan, B. J.; Bird, D. M.; Birks, T. A.; Knight, J. C.; Russell, P. St. J.

    2006-08-01

    A practical hollow-core photonic crystal fiber design suitable for attaining low-loss propagation is analyzed. The geometry involves a number of localized elliptical features positioned on the glass ring that surrounds the air core and separates the core and cladding regions. The size of each feature is tuned so that the composite core-surround geometry is antiresonant within the cladding band gap, thus minimizing the guided mode field intensity both within the fiber material and at material / air interfaces. A birefringent design, which involves a 2-fold symmetric arrangement of the features on the core-surround ring, gives rise to wavelength ranges where the effective index difference between the polarization modes is larger than 10-4. At such high birefringence levels, one of the polarization modes retains favorable field exclusion characteristics, thus enabling low-loss propagation of this polarization channel.

  20. Recent developments in laser-driven and hollow-core fiber optic gyroscopes

    Science.gov (United States)

    Digonnet, M. J. F.; Chamoun, J. N.

    2016-05-01

    Although the fiber optic gyroscope (FOG) continues to be a commercial success, current research efforts are endeavoring to improve its precision and broaden its applicability to other markets, in particular the inertial navigation of aircraft. Significant steps in this direction are expected from the use of (1) laser light to interrogate the FOG instead of broadband light, and (2) a hollow-core fiber (HCF) in the sensing coil instead of a conventional solid-core fiber. The use of a laser greatly improves the FOG's scale-factor stability and eliminates the source excess noise, while an HCF virtually eliminates the Kerr-induced drift and significantly reduces the thermal and Faraday-induced drifts. In this paper we present theoretical evidence that in a FOG with a 1085-m coil interrogated with a laser, the two main sources of noise and drift resulting from the use of coherent light can be reduced below the aircraft-navigation requirement by using a laser with a very broad linewidth, in excess of 40 GHz. We validate this concept with a laser broadened with an external phase modulator driven with a pseudo-random bit sequence at 2.8 GHz. This FOG has a measured noise of 0.00073 deg/√h, which is 30% below the aircraft-navigation requirement. Its measured drift is 0.03 deg/h, the lowest reported for a laser-driven FOG and only a factor of 3 larger than the navigation-grade specification. To illustrate the potential benefits of a hollow-core fiber in the FOG, this review also summarizes the previously reported performance of an experimental FOG utilizing 235 m of HCF and interrogated with broadband light.

  1. Determination of volatile organic compounds in water using headspace knotted hollow fiber microextraction.

    Science.gov (United States)

    Chen, Pai-Shan; Tseng, Yu-Hsiang; Chuang, Yuh-Lin; Chen, Jung-Hsuan

    2015-05-22

    An efficient and effective headspace microextraction technique named static headspace knotted hollow fiber microextraction (HS-K-HFME) has been developed for the determination of volatile organic compounds (VOCs) in water samples. The knot-shaped hollow fiber is filled with 25μL of the extraction solvent. The excess solvent forms a large droplet (13μL) and is held in the center of the knot. Even after 20min of extraction time at high temperature (95°C) without cooling, there was still enough volume of extraction solvent for gas chromatography-mass spectrometry (GC-MS) analysis, which extends the choice of solvents for headspace LPME. Moreover, the knot-shaped fiber has a larger extraction contact interface, which increases the rate of mass transfer between the headspace and extraction solvent film attached to the fiber, thus improving the extraction efficiency. The effects of extraction solvent, temperature, stirring rate, salt concentration and extraction time on extraction performance were optimized. The calibration curves exhibited coefficients of determination (R(2)) ranging from 0.9957 to 0.9999 and the limit of detection (LOD) ranged from 0.2 to 10μgL(-1). Relative standard deviations (RSDs) ranged from 4.5% to 11.6% for intraday measurements (n=5). Interday (n=15) values were between 2.2% and 12.9%. The relative recoveries (RRs) ranged from 90.3% to 106.0% for river water and 95.9% to 103.6% for wastewater.

  2. Fabrication of nanocrystalline hydroxyapatite doped degradable composite hollow fiber for guided and biomimetic bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Ning [Department of Bioengineering, Clemson University, Clemson, SC, 29634 (United States); Nichols, Heather L. [Department of Bioengineering, Clemson University, Clemson, SC, 29634 (United States); Tylor, Shila [Department of Bioengineering, Clemson University, Clemson, SC, 29634 (United States); Wen Xuejun [Department of Bioengineering, Clemson University, Clemson, SC, 29634 (United States)]. E-mail: xjwen@clemson.edu

    2007-04-15

    Natural bone tissue possesses a nanocomposite structure interwoven in a three-dimensional (3-D) matrix, which plays critical roles in conferring appropriate physical and biological properties to the bone tissue. Single type of material may not be sufficient to mimic the composition, structure and properties of native bone, therefore, composite materials consisting of both polymers, bioceramics, and other inorganic materials have to be designed. Among a variety of candidate materials, polymer-nanoparticle composites appear most promising for bone tissue engineering applications because of superior mechanical properties, improved durability, and surface bioactivity when compared with conventional polymers or composites. The long term objective of this project is to use highly aligned, bioactive, biodegradable scaffold mimicking natural histological structure of human long bone, and to engineer and regenerate human long bone both in vitro and in vivo. In this study, bioactive, degradable, and highly permeable composite hollow fiber membranes (HFMs) were fabricated using a wet phase phase-inversion approach. The structure of the hollow fiber membranes was examined using scanning electron microscopy (SEM); degradation behavior was examined using weigh loss assay, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC); and bioactivity was evaluated with the amount of calcium deposition from the culture media onto HFM surface. Doping PLGA HFMs with nanoHA results in a more bioactive and slower degrading HFM than pure PLGA HFMs.

  3. Expansion of activated lymphocytes obtained from renal cell carcinoma in an automated hollow fiber bioreactor.

    Science.gov (United States)

    Hillman, G G; Wolf, M L; Montecillo, E; Younes, E; Ali, E; Pontes, J E; Haas, G P

    1994-01-01

    Immunotherapy using IL-2 alone or combined with activated lymphocytes has been promising for metastatic renal cell carcinoma. Cytotoxic lymphocytes can be isolated from tumors, expanded in vitro with IL-2, and adoptively transferred back into the tumor-bearing host. These cells can also be transduced with the genes coding for cytokines for local delivery to tumor sites. A major drawback in adoptive immunotherapy is the cumbersome and expensive culture technology associated with the growth of large numbers of cells required for their therapeutic effect. To reduce the cost, resources, and manpower, we have developed the methodology for lymphocyte activation and expansion in the automated hollow fiber bioreactor IMMUNO*STAR Cell Expander (ACT BIOMEDICAL, INC). Tumor Infiltrating Lymphocytes (TIL) isolated from human renal cell carcinoma tumor specimens were inoculated at a number of 10(8) cells in a small bioreactor of 30 ml extracapillary space volume. We have determined the medium flow rates and culture conditions to obtain a significant and repeated expansion of TIL at weekly intervals. The lymphocytes cultured in the bioreactor demonstrated the same phenotype and cytotoxic activity as those expanded in parallel in tissue culture plates. Lymphocyte expansion in the hollow fiber bioreactor required lower volumes of medium, human serum, IL-2 and minimal labor. This technology may facilitate the use of adoptive immunotherapy for the treatment of refractory malignancies.

  4. Surface Plasmon Resonance Sensor Based on Ethylene Tetra-Fluoro-Ethylene Hollow Fiber

    Directory of Open Access Journals (Sweden)

    Pan Chen

    2015-11-01

    Full Text Available A new kind of hollow fiber surface plasmon resonance sensor (HF-SPRS based on the silver-coated ethylene tetra-fluoro-ethylene (ETFE hollow fiber (HF is presented. The ETFE HF-SPRS is fabricated, and its performance is investigated experimentally by measuring the transmission spectra of the sensor when filled by liquid sensed media with different refractive indices (RIs. Theoretical analysis based on the ray transmission model is also taken to evaluate the sensor. Because the RI of ETFE is much lower than that of fused silica (FSG, the ETFE HF-SPRS can extend the lower limit of the detection range of the early reported FSG HF-SPRS from 1.5 to 1.42 approximately. This could greatly enhance the application potential of HF-SPRS. Moreover, the joint use of both ETFE and FSG HF-SPRSs can cover a wide detection range from 1.42 to 1.69 approximately with high sensitivities larger than 1000 nm/RIU.

  5. Autohydrogenotrophic denitrification of drinking water using a polyvinyl chloride hollow fiber membrane biofilm reactor.

    Science.gov (United States)

    Zhang, Yanhao; Zhong, Fohua; Xia, Siqing; Wang, Xuejiang; Li, Jixiang

    2009-10-15

    A hollow fiber membrane biofilm reactor (MBfR) using polyvinyl chloride (PVC) hollow fiber was evaluated in removing nitrate form contaminated drinking water. During a 279-day operation period, the denitrification rate increased gradually with the increase of influent nitrate loading. The denitrification rate reached a maximum value of 414.72 g N/m(3)d (1.50 g N/m(2)d) at an influent NO(3)(-)-N concentration of 10mg/L and a hydraulic residence time of 37.5 min, and the influent nitrate was completely reduced. At the same time, the effluent quality analysis showed the headspace hydrogen content (3.0%) was lower enough to preclude having an explosive air. Under the condition of the influent nitrate surface loading of 1.04 g N/m(2)d, over 90% removal efficiencies of the total nitrogen and nitrate were achieved at the hydrogen pressure above 0.04 MPa. The results of denaturing gel gradient electrophoresis (DGGE), 16S rDNA gene sequence analysis, and hierarchical cluster analysis showed that the microbial community structures in MBfR were of low diversity, simple and stable at mature stages; and the beta-Proteobacteria, including Rhodocyclus, Hydrogenophaga, and beta-Proteobacteria HTCC379, probably play an important role in autohydrogenotrophic denitrification.

  6. The Performance and Fouling Control of Submerged Hollow Fiber (HF Systems: A Review

    Directory of Open Access Journals (Sweden)

    Ebrahim Akhondi

    2017-07-01

    Full Text Available The submerged membrane filtration concept is well-established for low-pressure microfiltration (MF and ultrafiltration (UF applications in the water industry, and has become a mainstream technology for surface-water treatment, pretreatment prior to reverse osmosis (RO, and membrane bioreactors (MBRs. Compared to submerged flat sheet (FS membranes, submerged hollow fiber (HF membranes are more common due to their advantages of higher packing density, the ability to induce movement by mechanisms such as bubbling, and the feasibility of backwashing. In view of the importance of submerged HF processes, this review aims to provide a comprehensive landscape of the current state-of-the-art systems, to serve as a guide for further improvements in submerged HF membranes and their applications. The topics covered include recent developments in submerged hollow fiber membrane systems, the challenges and developments in fouling-control methods, and treatment protocols for membrane permeability recovery. The highlighted research opportunities include optimizing the various means to manipulate the hydrodynamics for fouling mitigation, developing online monitoring devices, and extending the submerged HF concept beyond filtration.

  7. Separation of hydrogen from carbon monoxide using a hollow fiber polyimide membrane: experimental and simulation

    Energy Technology Data Exchange (ETDEWEB)

    Peer, M.; Mehdi Kamali, S.; Mahdeyarfar, M.; Mohammadi, T. [Research Laboratory for Separation Processes, Chemical Engineering Department, Tehran (Iran)

    2007-10-15

    The separation of hydrogen from carbon monoxide (syngas ratio adjustment) with polymeric membranes was investigated in this work. A polyimide hollow fiber membrane module was used for hydrogen separation. This polymer has shown large permeability and selectivity for hydrogen separation (selectivity of ca. 30). Permeation tests were carried out at different feed conditions. Feed flow rates were varied between 150-300 mL/min, temperature was varied in the range of 20-80 C and feed pressure was varied between 5-9 bar. Mixtures containing 0-50 % carbon monoxide were used when carrying out experiments. Measured membrane permeances for hydrogen and carbon monoxide were about 70-100 GPU (gas permeation units) and 3-5.5 GPU, respectively. In addition, a mathematical model for simulation of gas separation in hollow fiber membrane modules with all flow patterns (crossflow, countercurrent and cocurrent) was presented. This model can be used for calculation of membrane performance or its required surface area for a specific separation. Experimental results have shown good correlation with simulation results. Plasticization, competitive sorption and concentration polarization effect of carbon monoxide on membrane performance is shown with experimental results. This effect reduced hydrogen permeances in mixed gas experiments. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  8. Polyimide hollow fiber membranes for CO2 separation from wet gas mixtures

    Directory of Open Access Journals (Sweden)

    F. Falbo

    2014-12-01

    Full Text Available Matrimid®5218 hollow fiber membranes were prepared using the dry-wet spinning process. The transport properties were measured with pure gases (H2, CO2, N2, CH4 and O2 and with a mixture (30% CO2 and 70% N2 in dry and wet conditions at 25 ºC, 50 ºC, 60 ºC and 75 ºC and up to 600 kPa. Interesting values of single gas selectivity up to 60 ºC (between 31 and 28 for CO2/N2 and between 33 and 30 for CO2/CH4 in dry condition were obtained. The separation factor measured for the mixture was 20% lower compared to the single gas selectivity, in the whole temperature range analyzed. In saturation conditions the data showed that water influences the performance of the membranes, inducing a reduction of the permeance of all gases. Moreover, the presence of water caused a decrease of single gas selectivity and separation factor, although not so significant, highlighting the very high water resistance of hollow fiber membrane modules.

  9. Analysis of Hollow Fiber Temperature Sensor Filled with Graphene-Ag Composite Nanowire and Liquid.

    Science.gov (United States)

    Xu, Wei; Yao, Jianquan; Yang, Xianchao; Shi, Jia; Zhao, Junfa; Zhang, Cheng

    2016-10-08

    A hollow fiber temperature sensor filled with graphene-Ag composite nanowire and liquid is presented and numerically characterized. The coupling properties and sensing performances are analyzed by finite element method (FEM) using both wavelength and amplitude interrogations. Due to the asymmetrical surface plasmon resonance sensing (SPR) region, the designed sensor exhibits strong birefringence, supporting two separate resonance peaks in orthogonal polarizations. Results show that x-polarized resonance peak can provide much better signal to noise ratio (SNR), wavelength and amplitude sensitivities than y-polarized, which is more suitable for tempertature detecting. The graphene-Ag composite nanowire filled into the hollow fiber core can not only solve the oxidation problem but also avoid the metal coating. A wide temperature range from 22 ∘C to 47 ∘C with steps of 5 ∘C is calculated and the temperature sensitivities we obtained are 9.44 nm/ ∘C for x-polarized and 5.33 nm/ ∘C for y-polarized, much higher than other sensors of the same type.

  10. Mathematic Model of Unsteady Penetration Mass Transfer in Randomly Packed Hollow Fiber Membrane Module

    Institute of Scientific and Technical Information of China (English)

    张秀莉; 张泽廷; 张卫东; 郝欣

    2004-01-01

    Based on the membrane-based absorption experiment of CO2 into water, shell-side flow distribution and mass transfer in a randomly packed hollow fiber module have been analyzed using subchannel model and unsteady penetration mass transfer theory. The cross section of module is subdivided into many small cells which contains only one hollow-fiber. The cross sectional area distribution of these cells is presented by the normal probability density distribution function. It has been obtained that there was a most serious non-ideal flow in shell side at moderate mean packing density, and the large amount of fluid flowed and transferred mass through a small number of large voids. Thus mass transfer process is dominated by the fluid through the larger void area. The mass transfer process in each cell is described by the unsteady penetration theory. The overall mass transfer coefficient equals to the probability addition of the mean mass transfer coefficient in each cell. The comparisons of the values calculated by the model established with the empirical correlations and the experimental data of this work have been done.The predicted overall mass transfer coefficients are in good agreement with experimental data.

  11. Counteracting ammonia inhibition in anaerobic digestion by removal with a hollow fiber membrane contactor.

    Science.gov (United States)

    Lauterböck, B; Ortner, M; Haider, R; Fuchs, W

    2012-10-01

    The aim of the current study was to investigate the feasibility of membrane contactors for continuous ammonia (NH₃-N) removal in an anaerobic digestion process and to counteract ammonia inhibition. Two laboratory anaerobic digesters were fed slaughterhouse wastes with ammonium (NH₄⁺) concentrations ranging from 6 to 7.4 g/L. One reactor was used as reference reactor without any ammonia removal. In the second reactor, a hollow fiber membrane contactor module was used for continuous ammonia removal. The hollow fiber membranes were directly submerged into the digestate of the anaerobic reactor. Sulfuric acid was circulated in the lumen as an adsorbent solution. Using this set up, the NH₄⁺-N concentration in the membrane reactor was significantly reduced. Moreover the extraction of ammonia lowered the pH by 0.2 units. In combination that led to a lowering of the free NH₃-N concentration by about 70%. Ammonia inhibition in the reference reactor was observed when the concentration exceeded 6 g/L NH₄⁺-N or 1-1.2 g/L NH₃-N. In contrast, in the membrane reactor the volatile fatty acid concentration, an indicator for process stability, was much lower and a higher gas yield and better degradation was observed. The chosen approach offers an appealing technology to remove ammonia directly from media having high concentrations of solids and it can help to improve process efficiency in anaerobic digestion of ammonia rich substrates.

  12. Fabrication of Defect-Free Cellulose Acetate Hollow Fibers by Optimization of Spinning Parameters.

    Science.gov (United States)

    He, Xuezhong

    2017-06-05

    Spinning of cellulose acetate (CA) with the additive polyvinylpyrrolidone (PVP) in N-methyl-2-pyrrolidone (NMP) solvent under different conditions was investigated. The spinning parameters of air gap, bore fluid composition, flow rate of bore fluid, and quench bath temperature were optimized based on the orthogonal experiment design (OED) method and multivariate analysis. FTIR and scanning electron microscopy were used to characterize the membrane structure and morphology. Based on the conjoint analysis in Statistical Product and Service Solutions (SPSS) software, the importance of these parameters was identified as: air gap > bore fluid composition > flow rate of bore fluid > quench bath temperature. The optimal spinning condition with the bore fluid (water + NMP (85%)), air gap (25 mm), flow rate of bore fluid (40% of dope rate), and temperature of quench bath (50 °C) was identified to make high PVP content, symmetric cross-section and highly cross-linked CA hollow fibers. The results can be used to guide the spinning of defect-free CA hollow fiber membranes with desired structures and properties as carbon membrane precursors.

  13. Triple-bore hollow fiber membrane contactor for liquid desiccant based air dehumidification

    KAUST Repository

    Bettahalli, N.M. Srivatsa

    2016-04-26

    Dehumidification is responsible for a large part of the energy consumption in cooling systems in high humidity environments worldwide. Improving efficiency is therefore essential. Liquid desiccants offer a promising solution for dehumidification, as desired levels of humidity removal could be easily regulated. The use of membrane contactors in combination with liquid desiccant is attractive for dehumidification because they prevent direct contact between the humid air and the desiccant, removing both the potential for desiccant carryover to the air and the potential for contamination of the liquid desiccant by dust and other airborne materials, as well as minimizing corrosion. However, the expected additional mass transport barrier of the membrane surface can lower the expected desiccation rate per unit of desiccant surface area. In this context, hollow fiber membranes present an attractive option for membrane liquid desiccant contactors because of their high surface area per unit volume. We demonstrate in this work the performance of polyvinylidene fluoride (PVDF) based triple-bore hollow fiber membranes as liquid desiccant contactors, which are permeable to water vapor but impermeable to liquid water, for dehumidification of hot and humid air.

  14. A new coiled hollow-fiber module design for enhanced microfiltration performance in biotechnology

    Energy Technology Data Exchange (ETDEWEB)

    Luque, S.; Mallubhotla, H.; Gehlert, G.; Belfort, G. [Rensselaer Polytechnic Inst., New York (United States). Howard P. Isermann Dept. of Chemical Engineering; Kuriyel, R.; Dzengeleski, S.; Pearl, S. [Millipore Corp., Bedford, MA (United States). BioProcess Div.

    1999-11-05

    The microfiltration performance of a novel membrane module design with helically wound hollow fibers is compared with that obtained with a standard commercial-type crossflow module containing linear hollow fibers. Cell suspension (yeast, E. coli, and mammalian cell cultures) commonly clarified in the biotechnology industry are used for this comparison. The effect of variables such as transmembrane pressure, particle suspension concentration, and feed flow rate on membrane performance is evaluated. Normalized permeation fluxes versus flow rate or Dean number behave according to a heat transfer correlation obtained with centrifugal instabilities of the Taylor type. The microfiltration performance of this new module design, which uses secondary flows in helical tubes, is significantly better than an equivalent current commercial crossflow module when filtering suspensions relevant to the biotechnology industry. Flux and capacity improvements of up to 3.2-fold (constant transmembrane pressure operation) and 3.9-fold (constant flux operation), respectively, were obtained with the helical module over those for the linear module.

  15. Liposome preparation using a hollow fiber membrane contactor--application to spironolactone encapsulation.

    Science.gov (United States)

    Laouini, A; Jaafar-Maalej, C; Sfar, S; Charcosset, C; Fessi, H

    2011-08-30

    In this study, we present a novel liposome preparation technique suitable for the entrapment of pharmaceutical and cosmetic agents. This new method uses a membrane contactor in a hollow fiber configuration. In order to investigate the process, key parameters influence on the liposome characteristics was studied. It has been established that the vesicle size distribution decreased with the organic phase pressure decrease, the phospholipid concentration decreases and the aqueous to organic phase volume ratio increases. Liposomes were filled with a hydrophobic drug model, spironolactone that could be used for a paediatric medication. The mean size of drug-free and drug-loaded liposomes was, respectively, 113 ± 4 nm and 123 ± 3 nm. The zeta potential of drug-free and drug-loaded liposomes was, respectively, -43 ± 0.7 mV and -23 ± 0.6 mV. High entrapment efficiency values were successfully achieved (93 ± 1.12%). Transmission electron microscopy images revealed nanometric sized and spherical shaped oligo-lamellar vesicles. The release profile showed a rapid and complete release within about 5h. Additionally, special attention was paid on process reproducibility and long term lipid vesicles stability. Results confirmed the robustness of the hollow fiber module based technique. Moreover, the technique is simple, fast and has a potential for continuous production of nanosized liposome suspensions at large scale.

  16. Response surface methodology to evaluation the recovery of amylases by hollow fiber membrane

    Directory of Open Access Journals (Sweden)

    João Baptista Severo Júnior

    2007-07-01

    Full Text Available This work aimed to study the pH and the transmembrane pressure effects during the recovery of alpha and beta amylases enzymes from corn malt (Zea mays by hollow fiber membrane. The optimal condition was obtained for a statistical model, established by response surface methodology (RSM. The response surface analysis showed that the best operation condition for amylolitics enzymes recovery by hollow fiber membrane was 0.05 bar and pH 5.00, while the enzymes were purified about of 26 times.Este trabalho objetivou estudar o efeito do pH e da pressão trans-membrana durante a recuperação das enzimas alfa e beta amilases do malte de milho (Zea mays por membranas de fibras ocas, a obtenção das condições ótimas foi feita por um modelo estatístico, estabelecido pela metodologia de superfície de resposta (RSM. A análise da superfície de resposta mostrou que as melhores condições operacionais para a recuperação das enzimas amiloliticas por membranas de fibras ocas foi 0,05 bar e pH 5,00; onde as enzimas foram purificadas cerca de 26 vezes.

  17. Continuous preparation of polymer coated drug crystals by solid hollow fiber membrane-based cooling crystallization.

    Science.gov (United States)

    Chen, Dengyue; Singh, Dhananjay; Sirkar, Kamalesh K; Pfeffer, Robert

    2016-02-29

    A facile way to continuously coat drug crystals with a polymer is needed in controlled drug release. Conventional polymer coating methods have disadvantages: high energy consumption, low productivity, batch processing. A novel method for continuous polymer coating of drug crystals based on solid hollow fiber cooling crystallization (SHFCC) is introduced here. The drug acting as the host particle and the polymer for coating are Griseofulvin (GF) and Eudragit RL100, respectively. The polymer's cloud point temperature in its acetone solution was determined by UV spectrophotometry. An acetone solution of the polymer containing the drug in solution as well as undissolved drug crystals in suspension were pumped through the tube side of the SHFCC device; a cold liquid was circulated in the shell side to rapidly cool down the feed solution-suspension in the hollow-fiber lumen. The polymer precipitated from the solution and coated the suspended crystals due to rapid temperature reduction and heterogeneous nucleation; crystals formed from the solution were also coated by the polymer. Characterizations by scanning electron microscopy, thermogravimetric analysis, laser diffraction spectroscopy, X-ray diffraction, Raman spectroscopy, and dissolution tests show that a uniformly coated, free-flowing drug/product can be obtained under appropriate operating conditions without losing the drug's pharmaceutical properties and controlled release characteristics.

  18. Aminosilane-Functionalized Hollow Fiber Sorbents for Post-Combustion CO 2 Capture

    KAUST Repository

    Li, Fuyue Stephanie

    2013-07-03

    Increasing carbon dioxide emissions are generally believed to contribute to global warming. Developing new materials for capturing CO2 emitted from coal-fired plants can potentially mitigate the effect of these CO 2 emissions. In this study, we developed and optimized porous hollow fiber sorbents with both improved sorption capacities and rapid sorption kinetics by functionalizing aminosilane (N-(2-aminoethyl)-3- aminoisobutyldimethylmethoxysilane) to cellulose acetate hollow fibers as a "proof of concept". A lumen-side barrier layer was also developed in the aminosilane-functionalized cellulose acetate fiber sorbent to allow for facile heat exchange without significant mass transfer with the bore-side heat transfer fluid. The functionalized cellulose acetate fiber sorbents were characterized by pressure decay sorption measurements, multicomponent column chromatography, FT-IR, elemental analysis, and scanning electron microscopy. The carbon dioxide sorption capacity at 1 atm is 0.73 mmol/g by using the pressure decay apparatus. Multicomponent column chromatography measurements showed that aminosilane functionalized cellulose acetate fiber sorbent has a CO2 sorption capacity of 0.23 mmol/g at CO2 partial pressure 0.1 atm and 35 C in simulated flue gas. While this capacity is low, our proof of concept positions the technology to move forward to higher capacity with work that is underway. The presence of silicon and nitrogen elements in the elemental analysis confirmed the success of grafting along with FT-IR spectra which showed the absorbance peak (∼810 cm-1) for Si-C stretching. A cross-linked Neoprene material was used to form the lumen-side barrier layer. Preliminary data showed the required reduction in gas permeance to eliminate mixing between shell side and bore side fluid flows. Specifically the permeance was reduced from 10 000 GPUs for the neat fibers to 6.6 ± 0.1 and 3.3 ± 0.3 GPUs for the coated fibers. The selected lumen layer formation materials

  19. Metallic attenuated total reflection infrared hollow fibers for robust optical transmission systems

    Science.gov (United States)

    Jing, Chengbin; Guo, Hong; Hu, Zhigao; Yang, Pingxiong; Chu, Junhao; Liu, Aiyun; Shi, Yiwei

    2014-07-01

    A durable metallic attenuated total reflection (ATR) hollow fiber (bore size: 1.45 mm, wall thickness: 50 μm) was designed and fabricated based on a nickel capillary tube and hexagonal germanium dioxide (GeO2). The anomalous dispersion of the hexagonal GeO2 layer grown inside a nickel tube achieves low-loss light transmission at two peak-power wavelengths for CO2 laser devices (10.2 and 10.6 μm). An 11-28 W, 10.2 or 10.6 μm CO2 laser power was steadily delivered via a fiber elastically bent from 0° to 90° (radius: 45 cm) for over 40 min (transmission loss: 0.22 to 4.2 dB/m). Theoretically fitting the measured temperatures showed that front-end clipping caused greater thermal loading than the distributed mode absorption. The maximum external temperature of a nickel ATR fiber is much lower than that of a silica glass ATR fiber owing to their different heat dissipation abilities. The HE11 mode purity of the output beam profiles decreased from 90.3% to 44.7% as the bending angle increased from 0° to 90°. Large core sizes and wall roughnesses (scattering loss 0.04 dB/m) contributed to mode mixing and excess losses that were above the value predicted by the classical Marcatili and Schmeltzer equation (0.024-0.037 dB/m).

  20. Efficient 1.5-μm Raman generation in ethane-filled hollow-core fiber

    Science.gov (United States)

    Chen, Yubin; Gu, Bo; Wang, Zefeng; Lu, Qisheng

    2016-11-01

    We demonstrated for the first time a novel and effective method for obtaining both high peak-power and narrow linewidth 1.5 μm fiber sources through gas Raman effect in hollow core fibers. An Ethane-filled ice-cream antiresonance hollow-core fiber is pumped with a high peak-power pulse 1064 nm microchip laser, generating 1552.7 nm Stokes wave by pure vibrational stimulated Raman scattering of ethane molecules. A maximum peak-power of about 400 kW is achieved with 6 meter fiber length at 2 bar pressure, and the linewidth is about 6.3 GHz. The maximum Raman conversion efficiency of 1064 nm to 1552.7 nm is about 38%, and the corresponding laser slope efficiency is about 61.5%.

  1. Improved hollow-core photonic crystal fiber design for delivery of nanosecond pulses in laser micromachining applications.

    Science.gov (United States)

    Shephard, Jonathan D; Couny, Francois; Russell, Phillip St J; Jones, Julian D C; Knight, Jonathan C; Hand, Duncan P

    2005-07-20

    We report the delivery of high-energy nanosecond pulses (approximately 65 ns pulse width) from a high-repetition-rate (up to 100 kHz) Q-switched Nd:YAG laser through the fundamental mode of a hollow-core photonic crystal fiber (HC-PCF) at 1064 nm. The guided mode in the HC-PCF has a low overlap with the glass, allowing delivery of pulses with energies above those attainable with other fibers. Energies greater than 0.5 mJ were delivered in a single spatial mode through the hollow-core fiber, providing the pulse energy and high beam quality required for micromachining of metals. Practical micromachining of a metal sheet by fiber delivery has been demonstrated.

  2. Chromium:forsterite laser frequency comb stabilization and development of portable frequency references inside a hollow optical fiber

    Science.gov (United States)

    Thapa, Rajesh

    We have made significant accomplishments in the development of portable frequency standard inside hollow optical fibers. Such standards will improve portable optical frequency references available to the telecommunications industry. Our approach relies on the development of a stabilized Cr:forsterite laser to generate the frequency comb in the near-IR region. This laser is self referenced and locked to a CW laser which in turn is stabilized to a sub-Doppler feature of a molecular transition. The molecular transition is realized using a hollow core fiber filled with acetylene gas. We finally measured the absolute frequency of these molecular transitions to characterize the references. In this thesis, the major ideas, techniques and experimental results for the development and absolute frequency measurement of the portable frequency references are presented. A prism-based Cr:forsterite frequency comb is stabilized. We have effectively used the prism modulation along with power modulation inside the cavity in order to actively stabilize the frequency comb. We have also studied the carrier-envelope-offset frequency (f0) dynamics of the laser and its effect on laser stabilization. A reduction of f0 linewidth from ˜2 MHz to ˜20 kHz has also been observed. Both our in-loop and out-of-loop measurements of the comb stability showed that the comb is stable within a part in 1011 at 1-s gate time and is currently limited by our reference signal. In order to develop this portable frequency standard, saturated absorption spectroscopy is performed on the acetylene v1 + v3 band near 1532 nm inside different kinds of hollow optical fibers. The observed linewidths are a factor 2 narrower in the 20 mum fiber as compared to 10 mum fiber, and vary from 20-40 MHz depending on pressure and power. The 70 mum kagome fiber shows a further reduction in linewidth to less than 10 MHz. In order to seal the gas inside the hollow optical fiber, we have also developed a technique of splicing the

  3. Hollow fiber based quantum cascade laser spectrometer for fast and sensitive drug identification

    Science.gov (United States)

    Herbst, J.; Scherer, B.; Ruf, A.; Erb, J.; Lambrecht, A.

    2012-01-01

    Sensitive and fast identification of drugs or drug precursors is important and necessary in scenarios like baggage or container check by customs or police. Fraunhofer IPM is developing a laser spectrometer using external cavity quantum cascade lasers (EC-QCL) to obtain mid-infrared (IR) absorption spectra in the wavelength range of the specific vibrational bands of amphetamines and their precursors. The commercial EC-QCL covers a tuning range of about 225 cm-1 within 1.4 s. The system could be used for different sample types like bulk samples or liquid solutions. A sampling unit evaporates the sample. Because of small sample amounts a 3 m long hollow fiber with an inner volume smaller than 1ml is used as gas cell and wave guide for the laser beam. This setup is suitable as a detector of a gas chromatograph instead of a standard detector (TCD or FID). The advantage is the selective identification of drugs by their IR spectra in addition to the retention time in the gas chromatographic column. In comparison to Fourier Transform IR systems the EC-QCL setup shows a good mechanical robustness and has the advantage of a point light source. Because of the good fiber incoupling performance of the EC-QCL it is possible to use hollow fibers. So, a good absorption signal is achieved because of the long optical path in the small cell volume without significant dilution. In first laboratory experiments a detection limit in the microgram range for pseudo ephedrine is achieved.

  4. Hypocycloid-shaped hollow-core photonic crystal fiber Part II: cladding effect on confinement and bend loss.

    Science.gov (United States)

    Alharbi, M; Bradley, T; Debord, B; Fourcade-Dutin, C; Ghosh, D; Vincetti, L; Gérôme, F; Benabid, F

    2013-11-18

    We report on numerical and experimental studies on the influence of cladding ring-number on the confinement and bend loss in hypocycloid-shaped Kagome hollow core photonic crystal fiber. The results show that beyond the second ring, the ring number has a minor effect on confinement loss whereas the bend loss is strongly reduced with the ring-number increase. Finally, the results show that the increase in the cladding ring-number improves the modal content of the fiber.

  5. A novel extraction technique based on carbon nanotubes reinforced hollow fiber solid/liquid microextraction for the measurement of piroxicam and diclofenac combined with high performance liquid chromatography.

    Science.gov (United States)

    Song, Xin-Yue; Shi, Yan-Ping; Chen, Juan

    2012-10-15

    A novel design of carbon nanotubes reinforced hollow fiber solid/liquid phase microextraction (CNTs-HF-SLPME) was developed to determine piroxicam and diclofenac in different real water samples. Functionalized multi-walled carbon nanotubes (MWCNTs) were held in the pores of hollow fiber with sol-gel technology. The pores and lumen of carbon nanotubes reinforced hollow fiber were subsequently filled with a μL volume of organic solvent (1-octanol), and then the whole assembly was used for the extraction of the target analytes in direct immersion sampling mode. The target analytes were extracted from the sample by two extractants, one of which is organic solvent placed inside the pores and lumen of hollow fiber and the other one is CNTs held in the pores of hollow fiber. After extraction, the analytes were desorbed in acetonitrile and analyzed using high performance liquid chromatography. This novel extraction mode showed more excellent extraction performance in comparison with conventional hollow fiber liquid microextraction (without adding CNTs) and carbon nanotubes reinforced hollow fiber solid microextraction (CNTs held in the pores of hollow fiber, but no organic solvents placed inside the lumen of hollow fiber) under the respective optimum conditions. This method provided 47- and 184-fold enrichment factors for piroxicam and diclofenac, respectively, good inter-fiber repeatability and batch-to-batch reproducibility. Linearity was observed in the range of 20-960 μg L(-1) for piroxicam, and 10-2560 μg L(-1) for diclofenac, with correlation coefficients of 0.9985 and 0.9989, respectively. The limits of detection were 4.58 μg L(-1) for piroxicam and 0.40 μg L(-1) for diclofenac.

  6. Tailoring the surface charge of an ultrafiltration hollow fiber by addition of a polyanion to the coagulation bore liquid

    NARCIS (Netherlands)

    Kopec, K.K.; Dutczak, S.M.; Wessling, Matthias; Stamatialis, Dimitrios

    2011-01-01

    In this work, we report a new in-line method to tailor the surface properties of porous ultrafiltration membranes in a one-step spinning process. A highly charged polyimide P84 hollow fiber membrane can be obtained by dissolving as less as 3% of sulphonated poly(ether ether ketone) (SPEEK) in the bo

  7. Gas-liquid mass transfer in a cross-flow hollow fiber module : Analytical model and experimental validation

    NARCIS (Netherlands)

    Dindore, V. Y.; Versteeg, G. F.

    2005-01-01

    The cross-flow operation of hollow fiber membrane contactors offers many advantages and is preferred over the parallel-flow contactors for gas-liquid mass transfer operations. However, the analysis of such a cross-flow membrane gas-liquid contactor is complicated due to the change in concentrations

  8. Tailoring the surface charge of an ultrafiltration hollow fiber by addition of a polyanion to the coagulation bore liquid

    NARCIS (Netherlands)

    Kopec, K.K.; Dutczak, S.M.; Wessling, Matthias; Stamatialis, Dimitrios

    2011-01-01

    In this work, we report a new in-line method to tailor the surface properties of porous ultrafiltration membranes in a one-step spinning process. A highly charged polyimide P84 hollow fiber membrane can be obtained by dissolving as less as 3% of sulphonated poly(ether ether ketone) (SPEEK) in the

  9. Chemistry in a spinneret - On the interplay of crosslinking and phase inversion during spinning of novel hollow fiber membranes

    NARCIS (Netherlands)

    Kopec, K.K.; Dutczak, S.M.; Wessling, Matthias; Stamatialis, Dimitrios

    2011-01-01

    This work explores a new method of simultaneous membrane formation and chemical modification in a spinning process for fabricating asymmetric composite hollow fiber membranes. This method is based on controlled crosslinking reaction between the membrane forming polyimide P84 and the chemically

  10. Understanding origin of loss in large pitch hollow-core photonic crystal fibers and their design simplification.

    Science.gov (United States)

    Février, Sébastien; Beaudou, Benoît; Viale, Pierre

    2010-03-01

    It is now commonly accepted that, in large pitch hollow-core 'kagomé' lattice fibers, the loss spectrum is related to resonances of the thin silica webs in the photonic crystal cladding. Moreover, coherent scattering from successive holes' layers cannot be obtained and adding holes' layers does not decrease the loss level. In this communication, cross-comparison of experimental data and accurate numerical modeling is presented that helps demonstrate that waveguiding in large pitch hollow-core fibers arises from the antiresonance of the core surround only and does not originate from the photonic crystal cladding. The glass webs only mechanically support the core surround and are sources of extra leakage. Large pitch hollow-core fibers exhibit features of thin walled and thick walled tubular waveguides, the first one tailoring the transmission spectrum while the second one is responsible for the increased loss figure. As a consequence, an approximate calculus, based on specific features of both types of waveguides, gives the loss spectrum, in very good agreement with experimental data. Finally, a minimalist hollow-core microstructured fiber, the cladding of which consists of six thin bridges suspending the core surround, is proposed for the first time.

  11. On the subtle balance between competitive sorption and plasticization effects in asymmetric hollow fiber gas separation membranes

    NARCIS (Netherlands)

    Visser, Tymen; Koops, G.H.; Wessling, Matthias

    2005-01-01

    The paper describes the influence of a varying feed composition of CO2/CH4 and CO2/N2 mixtures on the gas separation performance of integrally skinned asymmetric PES/PI hollow fibers with an effective skin thickness of 0.27 ¿m. Normally, thin membrane structures (<3 ¿m) show accelerated plasticizati

  12. Hollow fiber cell fishing with high performance liquid chromatography for screening bioactive compounds from traditional Chinese medicines.

    Science.gov (United States)

    Xue, Xue; Li, Lihua; Chen, Xuan; Hu, Shuang; Bai, Xiaohong

    2013-03-08

    A novel hollow fiber cell fishing method with high performance liquid chromatography was proposed and used to screen, isolate, and analyze bioactive compounds from Traditional Chinese Medicines (TCMs). The active compounds that interact with the living cells acceptor inside the hollow fiber lumen were screened and isolated from the TCM extracts in phosphate buffer solution (pH 7.4). Subsequently, the active compounds bound to the cells were desorbed with methanol, and were analyzed using HPLC. HFCF with HPLC was introduced for the screening and analysis of lignans in Schisandra chinensis (Turcz) Baill and coumarins in Fructus Cnidii and Fructus Psoraleae. The surface properties of the hollow fibers filled with living cells were characterized. The nonspecific binding between the active centers of the hollow fibers and the bioactive compounds were investigated. The cell survival rates were determined before and after the screening. The repeatability of the method was tested. Some structures of the lignans and coumarins screened from TCMs were identified by the comparison to the retention times of the reference substances. HFCF-HPLC is a simple, fast, effective, and reliable method for the screening and analysis of bioactive compounds, and it can be extended to screen other bioactive compounds from TCMs.

  13. Weak polyelectrolyte multilayers as tunable separation layers for micro-pollutant removal by hollow fiber nanofiltration membranes

    NARCIS (Netherlands)

    Ilyas, Shazia; Mehran Abtahi, S.; Akkilic, Namik; Roesink, Hendrik Dirk Willem; de Vos, Wiebe Matthijs

    2017-01-01

    The presence of micro-pollutants in wastewater and in drinking water and its sources, is posing both environmental and health concerns. This work describes the development of weak polyelectrolyte multilayer (PEM) based hollow fiber nanofiltration (NF) membranes to remove micro-pollutants from

  14. Hollow fibers of poly(lactide-co-glycolide) and poly(epsilon-caprolactone) blends for vascular tissue engineering applications

    NARCIS (Netherlands)

    Diban, Nazely; Haimi, Suvi; Bolhuis-Versteeg, Lydia; Teixeira, Sandra; Miettinen, Susanna; Poot, Andre; Grijpma, Dirk; Stamatialis, Dimitrios

    2013-01-01

    At present the manufacture of small-diameter blood vessels is one of the main challenges in the field of vascular tissue engineering. Currently available vascular grafts rapidly fail due to development of intimal hyperplasia and thrombus formation. Poly(lactic-co-glycolic acid) (PLGA) hollow fiber (

  15. Passively mode-locked fiber laser based on a hollow-core photonic crystal fiber filled with few-layered graphene oxide solution.

    Science.gov (United States)

    Liu, Zhi-Bo; He, Xiaoying; Wang, D N

    2011-08-15

    We demonstrate a nanosecond-pulse erbium-doped fiber laser that is passively mode locked by a hollow-core photonic crystal fiber filled with few-layered graphene oxide solution. Owing to the good solution processing capability of few-layered graphene oxide, which can be filled into the core of a hollow-core photonic crystal fiber through a selective hole filling process, a graphene saturable absorber can be successfully fabricated. The output pulses obtained have a center wavelength, pulse width, and repetition rate of 1561.2 nm, 4.85 ns, and 7.68 MHz, respectively. This method provides a simple and efficient approach to integrate the graphene into the optical fiber system.

  16. Future perspectives of using hollow fibers as structured packings in light hydrocarbon distillation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Dali [Los Alamos National Laboratory; Orler, Bruce [Los Alamos National Laboratory; Tornga, Stephanie [Los Alamos National Laboratory; Welch, Cindy [Los Alamos National Laboratory

    2011-01-26

    Olefin and paraffin are the largest chemical commodities. Furthermore, they are major building blocks for the petrochemical industry. Each year, petroleum refining, consumes 4,500 TBtu/yr in separation energy, making it one of the most energy-intensive industries in the United States). Just considering liquefied petroleum gas (ethane/propane/butane) and olefins (ethylene and propylene) alone, the distillation energy consumption is about 400 TBtu/yr in the US. Since petroleum distillation is a mature technology, incremental improvements in column/tray design will only provide a few percent improvements in the performance. However, each percent saving in net energy use amounts to savings of 10 TBtu/yr and reduces CO{sub 2} emissions by 0.2 MTon/yr. In practice, distillation columns require 100 to 200 trays to achieve the desired separation. The height of a transfer unit (HTU) of conventional packings is typical in the range of 36-60 inch. Since 2006, we had explored using several non-selective membranes as the structured packings to replace the conventional packing materials used in propane and propylene distillation. We obtained the lowest HTU of < 8 inch for the hollow fiber column, which was >5 times shorter than that of the conventional packing materials. In 2008, we also investigated this type of packing materials in iso-/n-butane distillation. Because of a slightly larger relative volatility of iso-/n-butane than that of propane/propylene, a wider and a more stable operational range was obtained for the iso-/n-butane pair. However, all of the experiments were conducted on a small scale with flowrate of < 25 gram/min. Recently, we demonstrated this technology on a larger scale (<250 gram/min). Within the loading range of F-factor < 2.2 Pa{sup 0.5}, a pressure drop on the vapor side is below 50 mbar/m, which suggests that the pressure drop of hollow fibers packings is not an engineering barrier for the applications in distillations. The thermal stability study

  17. Characteristics of capacitively coupled RF helium/neon discharges in a hollow fiber

    Science.gov (United States)

    Duan, Lian; Wang, Xinbing; Zuo, Duluo

    2016-11-01

    Capacitively coupled radio-frequency microplasmas are produced in hollow fibers with an inner diameter of hundreds of micrometers powered by an 80-MHz power supply. Considering the narrow space of the hollow core, optical emission spectrometry is used to obtain the spatially resolved characteristics of the microplasmas. The rotational temperature, excitation temperature, and electron density of microplasmas are determined based on the second positive band of nitrogen, the atomic spectra of bulk neutral particles of plasmas, and the Hβ line of the hydrogen Balmer series, respectively. In our experiments, the rotational temperature, excitation temperature, and electron density of typical inert gases helium and neon are in the ranges of 300-500 K, 7000-9500 K, and 1013 cm-3, respectively. The results obtained with different external parameters of power and pressure show that the light emission intensity increases with power and pressure. The distributions of the rotational temperature, excitation temperature, and electron density of the microplasmas are almost constant over the gap between the electrodes. These distributions are mostly insensitive to the change of power and pressure in single-component plasmas. The characteristics of mixed plasmas are also investigated. The plasma with a larger helium content possesses higher excitation temperature and lower rotational temperature and electron density than those of the plasma with a lower helium content.

  18. Coherent light transmission properties of commercial photonic crystal hollow core optical fiber.

    Science.gov (United States)

    Cranch, G A; Miller, G A

    2015-11-01

    Photonic crystal hollow core fiber (PC-HCF) has enabled many exciting new applications in nonlinear optics and spectroscopy. However, to date there has been less impact in coherent applications where preservation of optical phase over long fiber lengths is crucial. This paper presents characteristics of three commercially available PC-HCFs relevant to coherent applications including higher-order mode analysis, birefringence and polarization-dependent loss, and their impact on coherent light transmission in PC-HCF. Multipath interference due to higher-order mode propagation and Fresnel reflection is shown to generate excess intensity noise in transmission, which can be suppressed by up to 20 dB through high frequency phase modulation of the source laser. To demonstrate the potential of PC-HCF in high performance sensing, a Mach-Zehnder interferometer (MZI) incorporating 10 m of PC-HCF in each arm is characterized and demonstrates a phase resolution (59×10(-9)  rad/Hz(1/2) at 30 kHz) close to the shot noise limit, which is better than can be achieved in a MZI made with the same length of single mode solid core fiber because of the limit set by fundamental thermodynamic noise (74×10(-9)  rad/Hz(1/2) at 30 kHz).

  19. Modeling and parametric analysis of hollow fiber membrane system for carbon capture from multicomponent flue gas

    KAUST Repository

    Khalilpour, Rajab

    2011-08-12

    The modeling and optimal design/operation of gas membranes for postcombustion carbon capture (PCC) is presented. A systematic methodology is presented for analysis of membrane systems considering multicomponent flue gas with CO 2 as target component. Simplifying assumptions is avoided by namely multicomponent flue gas represented by CO 2/N 2 binary mixture or considering the co/countercurrent flow pattern of hollow-fiber membrane system as mixed flow. Optimal regions of flue gas pressures and membrane area were found within which a technoeconomical process system design could be carried out. High selectivity was found to not necessarily have notable impact on PCC membrane performance, rather, a medium selectivity combined with medium or high permeance could be more advantageous. © 2011 American Institute of Chemical Engineers (AIChE).

  20. Monitoring of heparin concentration in serum by Raman spectroscopy within hollow core photonic crystal fiber

    Science.gov (United States)

    Khetani, Altaf; Tiwari, Vidhu S.; Harb, Alaa; Anis, Hanan

    2011-08-01

    The feasibility of using hollow core photonic crystal fiber (HC-PCF) in conjunction with Raman spectroscopy has been explored for real time monitoring of heparin concentration in serum. Heparin is an important blood anti-coagulant whose precise monitoring and controlling in patients undergoing cardiac surgery and dialysis is of utmost importance. Our method of heparin monitoring offers a novel alternative to existing clinical procedures in terms of accuracy, response time and sample volume. The optical design configuration simply involves a 785-nm laser diode whose light is coupled into HC-PCF filled with heparin-serum mixtures. By non-selectively filling HC-PCF, a strong modal field overlap is obtained. Consequently, an enhanced Raman signal (>90 times) is obtained from various heparin-serum mixtures filled HC-PCFs compared to its bulk counterpart (cuvette). The present scheme has the potential to serve as a `generic biosensing tool' for diagnosing a wide range of biological samples.

  1. Examining metal nanoparticle surface chemistry using hollow-core, photonic-crystal, fiber-assisted SERS.

    Science.gov (United States)

    Eftekhari, Fatemeh; Lee, Anna; Kumacheva, Eugenia; Helmy, Amr S

    2012-02-15

    In this Letter, we demonstrate the efficacy of hollow core photonic crystal fibers (HCPCFs) as a surface-enhanced Raman spectroscopy (SERS) platform for investigating the ligand exchange process on the surface of gold nanoparticles. Raman measurements carried out using this platform show the capability to monitor minute amounts of surface ligands on gold nanoparticles used as an SERS substrate. The SERS signal from an HCPCF exhibits a tenfold enhancement compared to that in a direct sampling scheme using a cuvette. Using exchange of cytotoxic cetyltrimethylammonium bromide with α-methoxy-ω-mercaptopoly(ethylene glycol) on the surface of gold nanorods as an exemplary system, we show the feasibility of using HCPCF SERS to monitor the change in surface chemistry of nanoparticles.

  2. High Pressure Gases in Hollow Core Photonic Crystal Fiber:A New Nonlinear Medium

    CERN Document Server

    Azhar, Mohiudeen; Chang, Wonkeun; Joly, Nicolas; Russell, Philip

    2012-01-01

    The effective Kerr nonlinearity of hollow-core kagome-style photonic crystal fiber (PCF) filled with argon gas increases over 100 times when the pressure is increased from 1 to 150 bar, reaching 15 % of that of bulk silica glass, while the zero dispersion wavelength shifts from 300 to 900 nm. The group velocity dispersion of the system is uniquely pressure-tunable over a wide range while avoiding Raman scattering : absent in noble gases and having an extremely high optical damage threshold. As a result, detailed and well controlled studies of nonlinear effects can be performed, in both normal and anomalous dispersion regimes, using only a fixed-frequency pump laser. For example, the absence of Raman scattering permits clean observation, at high powers, of the interaction between a modulational instability side-band and a soliton created dispersive wave. Excellent agreement is obtained between numerical simulations and experimental results. The system has great potential for the realisation of reconfigurable s...

  3. Hyperlayer hollow-fiber flow field-flow fractionation of cells.

    Science.gov (United States)

    Reschiglian, Pierluigi; Zattoni, Andrea; Roda, Barbara; Cinque, Leonardo; Melucci, Dora; Min, Byung Ryul; Moon, Myeong Hee

    2003-01-24

    Interest in low-cost, analytical-scale, highly efficient and sensitive separation methods for cells, among which bacteria, is increasing. Particle separation in hollow-fiber flow field-flow fractionation (HF FlFFF) has been recently improved by the optimization of the HF FIFFF channel design. The intrinsic simplicity and low cost of this HF FlFFF channel allows for its disposable usage. which is particularly appealing for analytical bio-applications. Here, for the first time, we present a feasibility study on high-performance, hyperlayer HF FIFFF of micrometer-sized bacteria (Escherichia coli) and of different types of cells (human red blood cells, wine-making yeast from Saccharomyces cerevisiae). Fractionation performance is shown to be at least comparable to that obtained with conventional, flat-channel hyperlayer FIFFF of cells, at superior size-based selectivity and reduced analysis time.

  4. Mechanism of hollow-core-fiber infrared-supercontinuum compression with bulk material

    Science.gov (United States)

    Béjot, P.; Schmidt, B. E.; Kasparian, J.; Wolf, J.-P.; Legaré, F.

    2010-06-01

    We numerically investigate the pulse compression mechanism in the infrared spectral range based on the successive action of nonlinear pulse propagation in a hollow-core fiber followed by linear propagation through bulk material. We found an excellent agreement of simulated pulse properties with experimental results at 1.8 μm in the two-optical-cycle regime close to the Fourier limit. In particular, the spectral phase asymmetry attributable to self-steepening combined with self-phase modulation is a necessary prerequisite for subsequent compensation by the phase introduced by glass material in the anomalous dispersion regime. The excellent agreement of the model enabled simulating pressure and wavelength tunability of sub-two cycles in the range from 1.5 to 4 μm with this cost-efficient and robust approach.

  5. Numerical Simulation and Analysis of CO2 Removal in a Polypropylene Hollow Fiber Membrane Contactor

    Directory of Open Access Journals (Sweden)

    Zhien Zhang

    2014-01-01

    Full Text Available This present study shows a comprehensive 2D numerical model for removal of CO2 in a polypropylene (PP hollow fiber membrane contactor (HFMC using the computational fluid dynamics (CFD method. Monoethanolamine (MEA solution was used as the liquid absorbent in a nonwetting mode. The simulation results represented that higher liquid velocity and concentration and lower gas velocity and concentration led to higher percent of CO2 removal. The most proper parameters for CO2 removal were less than 1 mol m−3 gas concentration and 0.2 m s−1 gas flow rate, and for MEA the values were above 8 mol m−3 concentration and approximately 1 m s−1 liquid velocity. Furthermore, the model was validated with the experiment results. Therefore, the modeling results provided references to the selection of absorbents and operation parameters in the experimental study and pilot-scale applications.

  6. Hybrid Anion Exchange Hollow Fiber Membrane for Delivery of Ionic Drugs

    Directory of Open Access Journals (Sweden)

    Na Wang

    2012-01-01

    Full Text Available Hybrid anion exchange hollow fiber membranes (HAEHFMs based on bromomethylated poly(2,6-dimethyl-1,4-phenylene oxide (BPPO are proposed as potential drug carriers for four anionic model drugs, including the sodium salts of benzoate (NaBS, salicylate (NaSA, meta-amino salicylate (NaMAS, and loxoprofen (NaLS. The results of the static loading and release experiments suggest that electrostatic interaction, hydrogen bonding, and hydrophobic interaction are the main interaction patterns between the membrane and the drugs. And they are directly influenced by the external phase conditions and the drug physicochemical characteristics, such as structure, molecular weight, dissociation (pKa, and hydrogen bonding capability. Among the four different drugs, NaSA and NaMAS appear to be the most suitable for controlled release by the HAEHFM due to their excellent adsorption/release behaviors.

  7. Synthesis and characterization of polycaprolactone urethane hollow fiber membranes as small diameter vascular grafts.

    Science.gov (United States)

    Mercado-Pagán, Ángel E; Stahl, Alexander M; Ramseier, Michelle L; Behn, Anthony W; Yang, Yunzhi

    2016-07-01

    The design of bioresorbable synthetic small diameter (biodegradable polycaprolactone (PCL) urethane macromers to fabricate hollow fiber membranes (HFMs) as SDVG candidates, and characterized their mechanical properties, degradability, hemocompatibility, and endothelial development. The HFMs had smooth surfaces and porous internal structures. Their tensile stiffness ranged from 0.09 to 0.11N/mm and their maximum tensile force from 0.86 to 1.03N, with minimum failure strains of approximately 130%. Permeability varied from 1 to 14×10(-6)cm/s, burst pressures from 1158 to 1468mmHg, and compliance from 0.52 to 1.48%/100mmHg. The suture retention forces ranged from 0.55 to 0.81N. HFMs had slow degradation profiles, with 15 to 30% degradation after 8weeks. Human endothelial cells proliferated well on the HFMs, creating stable cell layer coverage. Hemocompatibility studies demonstrated low hemolysis (biodegradable elastomeric HFMs as SDVG candidates.

  8. Toluene impurity effects on CO2 separation using a hollow fiber membrane for natural gas

    KAUST Repository

    Omole, Imona C.

    2011-03-01

    The performance of defect-free cross-linkable polyimide asymmetric hollow fiber membranes was characterized using an aggressive feed stream containing up to 1000ppm toluene. The membrane was shown to be stable against toluene-induced plasticization compared with analogs made from Matrimid®, a commercial polyimide. Permeation and sorption analysis suggest that the introduction of toluene vapors in the feed subjects the membrane to antiplasticization, as the permeance decreases significantly (to less than 30%) under the most aggressive conditions tested. Separation efficiencies reflected by permselectivities were less affected. The effect of the toluene on the membrane was shown to be reversible when the toluene was removed. © 2010 Elsevier B.V.

  9. Hollow-core photonic bandgap fibers for orbital angular momentum applications

    Science.gov (United States)

    Li, H.; Ren, G.; Gao, Y.; Zhu, B.; Wang, J.; Yin, B.; Jian, S.

    2017-04-01

    We present a study on the potential and challenges of guiding orbital angular momentum (OAM) modes in hollow-core photonic bandgap fibers (HC-PBGFs). Two 19-cell HC-PBGFs with different structural parameters are comparably investigated. The OAM mode properties in a 37-cell HC-PBGF are also discussed to explore the scalability of OAM states. Characteristics of vector modes and OAM modes are comprehensively analyzed with numerical simulations. The results show HC-PBGF with a larger core could effectively support more OAM modes with lower confinement loss and a larger effective area. In addition, HC-PBGF with a deeper and wider photonic bandgap is advantageous for achieving low crosstalk OAM transmission over a broader band-width. 19-cell HC-PBGFs could support OAM modes with purity beyond 0.9, and the value can be further improved by exploiting the 37-cell HC-PBGF.

  10. A pseudobiospecific hollow fiber cartridge for in vitro adsorption of autoantibodies from pathological serum

    Directory of Open Access Journals (Sweden)

    Ventura R.C.A.

    2000-01-01

    Full Text Available The affinity filtration technique using histidine as a pseudobiospecific ligand immobilized on poly(ethylene vinyl alcohol hollow fiber membranes (His-PEVA was used to remove autoantibodies from serum of patients with autoimmune disease. The effects of buffering solution conditions on the efficiency of autoantibodies removal was studied. The removal of anti-dsDNA, anti-SS-A/Ro, anti-Sm, anti-Sm/RNP and anti-cardiolipin autoantibodies present in the serum was investigated, comparing the efficiency between Hepes and Tris-HCl buffers. The results showed the potential of the membrane to remove all the autoantibodies studied. Anti SS-A/Ro was removed more efficiently in Tris-HCl buffer system rather than with the Hepes buffer.

  11. Hollow fiber liquid-supported membrane technology for enantioseparation of racemic salbutamol by combinatorial chiral selectors

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Enantioseparation of salbutamol solute was carried out in liquid-supported membrane by using a polyvinylidene fluoride hollow-fiber module. The enantioselective transport of solute was facilitated by combinatorial chiral selectors, which were dissolved in toluene organic solvent. The effects of molar concentration ratios of salbutamol to combinatorial chiral selectors, and the pH value of buffer solution on enantioseparation were investigated. The results show that when the molar concentration ratio is 2: 1:1, the maximum separation factor and enantiomer excess are 1.49 and 19.74%, respectively, and the R-enantiomer flux is more than S-enantiomer; the pH value of buffer solution influences the performances of enantioseparartion obviously, and the appropriate range of pH value is7.0-7.2.

  12. Voltage-controlled separation of proteins by electromobility focusing in a dialysis hollow fiber.

    Science.gov (United States)

    Wang, Qinggang; Lin, Shu-Ling; Warnick, Karl F; Tolley, H Dennis; Lee, Milton L

    2003-01-24

    Electromobility focusing (EMF) is a relatively new protein separation technique that utilizes an electric field gradient and a hydrodynamic flow. Proteins are focused in order of electrophoretic mobility at points where their electrophoretic migration velocities balance the hydrodynamic flow velocity. Steady state bands are formed along the separation channel when equilibrium is reached. Further separation and detection can be easily achieved by changing the electric field profile. In this paper. we describe an EMF system with on-line UV absorption detection in which the electric field gradient was formed using a dialysis hollow fiber. Protein focusing and preconcentration were performed with this system. Voltage-controlled separation was demonstrated using bovine serum albumin and myoglobin as model proteins. The limitations of the current method are discussed, and possible solutions are proposed.

  13. Method and device for detecting impact events on a security barrier which includes a hollow rebar allowing insertion and removal of an optical fiber

    Science.gov (United States)

    Pies, Ross E.

    2016-03-29

    A method and device for the detection of impact events on a security barrier. A hollow rebar is farmed within a security barrier, whereby the hollow rebar is completely surrounded by the security barrier. An optical fiber passes through the interior of the hollow rebar. An optical transmitter and an optical receiver are both optically connected to the optical fiber and connected to optical electronics. The optical electronics are configured to provide notification upon the detection of an impact event at the security barrier based on the detection of disturbances within the optical fiber.

  14. Hollow-fiber ultrafiltration for simultaneous recovery of viruses, bacteria and parasites from reclaimed water.

    Science.gov (United States)

    Liu, Pengbo; Hill, Vincent R; Hahn, Donghyun; Johnson, Trisha B; Pan, Yi; Jothikumar, Narayanan; Moe, Christine L

    2012-01-01

    Hollow-fiber ultrafiltration (UF) is a technique that has been reported to be effective for recovering a diverse array of microbes from water, and may also be potentially useful for microbial monitoring of effluent from water reclamation facilities. However, few data are available to indicate the potential limitations and efficacy of the UF technique for treated wastewater. In this study, recovery efficiencies were determined for various options available for performing the tangential-flow UF technique, including hollow-fiber ultrafilter (i.e., dialyzer) type, ultrafilter pre-treatment (i.e., blocking), and elution. MS2 and ΦX174 bacteriophages, Clostridium perfringens spores, Escherichia coli, and Cryptosporidium parvum oocysts were seeded into 10-L reclaimed water samples to evaluate UF options. Then a single UF protocol was established and studied using seeded and non-seeded 100-L samples from two water reclamation facilities in Georgia, USA. Baxter Exeltra Plus 210 and Fresenius F200NR dialyzers were found to provide significantly higher microbial recovery than Minntech HPH 1400 hemoconcentrators. The selected final UF method incorporated use of a non-blocked ultrafilter for UF followed by elution using a surfactant-based solution. For 10-L samples, this method achieved recovery efficiencies of greater than 50% recovery of seeded viruses, bacteria, and parasites. There was no significant difference in overall microbial recovery efficiency when the method was applied to 10- and 100-L samples. In addition, detection levels for pathogens in seeded 100-L reclaimed water samples were 1000 PFU HAV, 10,000 GI norovirus particles, <500 Salmonella and <200 Cryptosporidium oocysts. These data demonstrate that UF can be an effective technique for recovering diverse microbes in reclaimed water to monitor and improve effluent water quality in wastewater treatment plants.

  15. Synthesis and characterization of polycaprolactone urethane hollow fiber membranes as small diameter vascular grafts

    Energy Technology Data Exchange (ETDEWEB)

    Mercado-Pagán, Ángel E. [Department of Orthopedic Surgery, Stanford University, Stanford, CA (United States); Stahl, Alexander M. [Department of Orthopedic Surgery, Stanford University, Stanford, CA (United States); Department of Chemistry, Stanford University, Stanford, CA (United States); Ramseier, Michelle L. [Department of Orthopedic Surgery, Stanford University, Stanford, CA (United States); Department of Chemical Engineering, Stanford University, Stanford, CA (United States); Behn, Anthony W. [Department of Orthopedic Surgery, Stanford University, Stanford, CA (United States); Yang, Yunzhi, E-mail: ypyang@stanford.edu [Department of Orthopedic Surgery, Stanford University, Stanford, CA (United States); Department of Materials Science and Engineering, Stanford University, Stanford, CA (United States); Department of Bioengineering, Stanford University, Stanford, CA (United States)

    2016-07-01

    The design of bioresorbable synthetic small diameter (< 6 mm) vascular grafts (SDVGs) capable of sustaining long-term patency and endothelialization is a daunting challenge in vascular tissue engineering. Here, we synthesized a family of biocompatible and biodegradable polycaprolactone (PCL) urethane macromers to fabricate hollow fiber membranes (HFMs) as SDVG candidates, and characterized their mechanical properties, degradability, hemocompatibility, and endothelial development. The HFMs had smooth surfaces and porous internal structures. Their tensile stiffness ranged from 0.09 to 0.11 N/mm and their maximum tensile force from 0.86 to 1.03 N, with minimum failure strains of approximately 130%. Permeability varied from 1 to 14 × 10{sup −6} cm/s, burst pressures from 1158 to 1468 mm Hg, and compliance from 0.52 to 1.48%/100 mm Hg. The suture retention forces ranged from 0.55 to 0.81 N. HFMs had slow degradation profiles, with 15 to 30% degradation after 8 weeks. Human endothelial cells proliferated well on the HFMs, creating stable cell layer coverage. Hemocompatibility studies demonstrated low hemolysis (< 2%), platelet activation, and protein adsorption. There were no significant differences in the hemocompatibility of HFMs in the absence and presence of endothelial layers. These encouraging results suggest great promise of our newly developed materials and biodegradable elastomeric HFMs as SDVG candidates. - Highlights: • Polyester urethane hollow fiber membranes (HFMs) were fabricated and evaluated. • HFM properties varied according to composition. • HFM inner and outer surfaces were successfully seeded with cells. • HFMs showed excellent hemocompatibility in vitro. • HFM has the potential to be used for small diameter vascular grafts.

  16. Development and evaluation of elastomeric hollow fiber membranes as small diameter vascular graft substitutes

    Energy Technology Data Exchange (ETDEWEB)

    Mercado-Pagán, Ángel E.; Kang, Yunqing [Department of Orthopedic Surgery, Stanford University, Stanford, CA (United States); Findlay, Michael W. [Department of Plastic and Reconstructive Surgery, Stanford University, Stanford, CA (United States); University of Melbourne Department of Surgery, Royal Melbourne Hospital, Parkville, VIC (Australia); Yang, Yunzhi, E-mail: ypyang@stanford.edu [Department of Orthopedic Surgery, Stanford University, Stanford, CA (United States); Department of Materials Science and Engineering, Stanford University, Stanford, CA (United States)

    2015-04-01

    Engineering of small diameter (< 6 mm) vascular grafts (SDVGs) for clinical use remains a significant challenge. Here, elastomeric polyester urethane (PEU)-based hollow fiber membranes (HFMs) are presented as an SDVG candidate to target the limitations of current technologies and improve tissue engineering designs. HFMs are fabricated by a simple phase inversion method. HFM dimensions are tailored through adjustments to fabrication parameters. The walls of HFMs are highly porous. The HFMs are very elastic, with moduli ranging from 1–4 MPa, strengths from 1–5 MPa, and max strains from 300–500%. Permeability of the HFMs varies from 0.5–3.5 × 10{sup −6} cm/s, while burst pressure varies from 25 to 35 psi. The suture retention forces of HFMs are in the range of 0.8 to 1.2 N. These properties match those of blood vessels. A slow degradation profile is observed for all HFMs, with 71 to 78% of the original mass remaining after 8 weeks, providing a suitable profile for potential cellular incorporation and tissue replacement. Both human endothelial cells and human mesenchymal stem cells proliferate well in the presence of HFMs up to 7 days. These results demonstrate a promising customizable PEU HFMs for small diameter vascular repair and tissue engineering applications. - Highlights: • Hollow fiber membranes (HFMs) were fabricated and evaluated. • HFM properties could be tailored through adjustments to fabrication parameters. • Properties could match or exceed those of blood vessels. • HFM showed excellent compatibility in vitro. • HFMs have the potential to be used for small diameter vascular grafts.

  17. Hollow fiber optics with improved durability for high-peak-power pulses of Q-switched Nd:YAG lasers.

    Science.gov (United States)

    Matsuura, Yuji; Tsuchiuchi, Akio; Noguchi, Hiroshi; Miyagi, Mitsunobu

    2007-03-10

    To improve the damage threshold of hollow optical waveguides for transmitting Q-switched Nd:YAG laser pulses, we optimize the metallization processes for the inner coating of fibers. For silver-coated hollow fiber as the base, second, and third Nd:YAG lasers, drying silver films at a moderate temperature and with inert gas flow is found to be effective. By using this drying process, the resistance to high-peak-power optical pulse radiation is drastically improved for fibers fabricated with and without the sensitizing process. The maximum peak power transmitted in the fiber is greater than 20 MW. To improve the energy threshold of aluminum-coated hollow fibers for the fourth and fifth harmonics of Nd:YAG lasers, a thin silver film is added between the aluminum film and the glass substrate to increase adhesion of the aluminum coating. By using this primer layer, the power threshold improves to 3 MW for the fourth harmonics of a Q-switched Nd:YAG laser light.

  18. Portable optical frequency standard based on sealed gas-filled hollow-core fiber using a novel encapsulation technique

    DEFF Research Database (Denmark)

    Triches, Marco; Brusch, Anders; Hald, Jan

    2015-01-01

    A portable stand-alone optical frequency standard based on a gas-filled hollow-core photonic crystal fiber is developed to stabilize a fiber laser to the 13C2H2 P(16) (ν1 + ν3) transition at 1542 nm using saturated absorption. A novel encapsulation technique is developed to permanently seal...... the hollow-core fiber with easy light coupling, showing negligible pressure increase over two months. The locked laser shows a fractional frequency instability below 8 × 10−12 for an averaging time up to 104 s. The lock-point repeatability over one month is 2.6 × 10−11, corresponding to a standard deviation...

  19. Formation of sub pico-liter liquid periodic structure in a hollow optical fiber for photonic device applications

    Science.gov (United States)

    Hwang, Jihyun; Kim, Jongki; Park, Jiyoung; Oh, Kyunghwan

    2014-09-01

    We report a unique technique to generate a liquid periodic structure whose unit volume is as low as a few hundred femto-liter. Liquids such as water, toluene and ethanol were filled in a hollow optical fiber (hole diameter of 8 and 13μm), which were locally heated by a traversing miniature electric furnace. The periods between droplets could be varied flexibly in the range from 14 to 100μm and the volume of individual droplet was in the range from 112 to 845 femto-liter. We also fabricated the periodic liquid droplets with quantum dots, whose fluorescence was successfully measured in each droplet. These periodic liquid droplets could serve as flexible liquid long period fiber grating for the hollow optical fiber, which can be further applied in various mechanical and bio-chemical sensors

  20. Design and fabrication of hollow-core photonic crystal fibers for high-power ultrashort pulse transportation and pulse compression.

    Science.gov (United States)

    Wang, Y Y; Peng, Xiang; Alharbi, M; Dutin, C Fourcade; Bradley, T D; Gérôme, F; Mielke, Michael; Booth, Timothy; Benabid, F

    2012-08-01

    We report on the recent design and fabrication of kagome-type hollow-core photonic crystal fibers for the purpose of high-power ultrashort pulse transportation. The fabricated seven-cell three-ring hypocycloid-shaped large core fiber exhibits an up-to-date lowest attenuation (among all kagome fibers) of 40 dB/km over a broadband transmission centered at 1500 nm. We show that the large core size, low attenuation, broadband transmission, single-mode guidance, and low dispersion make it an ideal host for high-power laser beam transportation. By filling the fiber with helium gas, a 74 μJ, 850 fs, and 40 kHz repetition rate ultrashort pulse at 1550 nm has been faithfully delivered at the fiber output with little propagation pulse distortion. Compression of a 105 μJ laser pulse from 850 fs down to 300 fs has been achieved by operating the fiber in ambient air.

  1. Composite polymer/oxide hollow fiber contactors: versatile and scalable flow reactors for heterogeneous catalytic reactions in organic synthesis.

    Science.gov (United States)

    Moschetta, Eric G; Negretti, Solymar; Chepiga, Kathryn M; Brunelli, Nicholas A; Labreche, Ying; Feng, Yan; Rezaei, Fateme; Lively, Ryan P; Koros, William J; Davies, Huw M L; Jones, Christopher W

    2015-05-26

    Flexible composite polymer/oxide hollow fibers are used as flow reactors for heterogeneously catalyzed reactions in organic synthesis. The fiber synthesis allows for a variety of supported catalysts to be embedded in the walls of the fibers, thus leading to a diverse set of reactions that can be catalyzed in flow. Additionally, the fiber synthesis is scalable (e.g. several reactor beds containing many fibers in a module may be used) and thus they could potentially be used for the large-scale production of organic compounds. Incorporating heterogeneous catalysts in the walls of the fibers presents an alternative to a traditional packed-bed reactor and avoids large pressure drops, which is a crucial challenge when employing microreactors. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Oriented functionalization of natural hollow kapok fiber for highly efficient removal of toxic Hg(II from aqueous solution

    Directory of Open Access Journals (Sweden)

    Feng eWang

    2016-02-01

    Full Text Available Due to hollow and tubular structure, a natural kapok fiber (KF was used as the support and orientation matrix to control the polymerization of ethyleneglycol dimethacrylate (EGDMA and N-vinylimidazole (VIM along its inherent axial surface via a facile in situ rapid polymerization reaction in air atmosphere. The as-formed KF@VIM/EGDMA composite is featured with porous surface and rich N-containing functional groups for potential application as a highly efficient adsorbent for removal of toxic Hg(II from aqueous solution. The variables affecting the adsorption capacity were studied, including monomer ratio, external pH values, contact time, and initial Hg(II concentration. The pseudo-second-order equation and two adsorption isotherms including Langmuir and Freundlich equations were applied to determine the adsorption kinetics and adsorption capacity. The results show that the as-prepared KF@VIM/EGDMA composite has a maximum adsorption capacity of 697 mg/g to Hg(II, while no appreciable adsorption capacity can be found for KF itself. Given its intrinsic large lumen, faster adsorption kinetics (45 min are also expected and observed for KF@VIM/EGDMA. After a simple filtration, this adsorbent can be directly separated from the aqueous solution and then be regenerated for multi-cyclable utilization. During the adsorption process, the chemical complexing represents the main adsorption mechanism. As a naturally renewable KF, such a simple preparation method opens a new avenue to develop highly efficient and economically viable adsorbent for removal of toxic heavy metal from aqueous solution.

  3. Prospects for diode-pumped alkali-atom-based hollow-core photonic-crystal fiber lasers.

    Science.gov (United States)

    Sintov, Yoav; Malka, Dror; Zalevsky, Zeev

    2014-08-15

    By employing large hollow-core Kagome fiber in a double-clad configuration, the performance of a potentially rubidium vapor-based fiber laser is explored. The absorbed power and laser efficiency versus pump power are calculated utilizing a simple laser model. Our results show that a Kagome-based high-power fiber laser is feasible provided that the value of the collisional fine-structure mixing rate will be elevated by increasing the ambient temperature or by increasing the helium pressure.

  4. Ultra low-loss hypocycloid-core Kagome hollow-core photonic crystal fiber for green spectral-range applications.

    Science.gov (United States)

    Debord, B; Alharbi, M; Benoît, A; Ghosh, D; Dontabactouny, M; Vincetti, L; Blondy, J-M; Gérôme, F; Benabid, F

    2014-11-01

    We report on the development of a hypocycloidal-core Kagome hollow-core photonic crystal fiber guiding, with low transmission loss in the 450-650 nm visible spectral range. Transmission loss records have been achieved with 70  dB/km at 600 nm, and 130  dB/km at 532 nm. As a demonstration of the fiber potential applications, we report on a compact 600 THz wide Raman comb generator, centered around 532 nm, and on a 10 W average power frequency-doubled Yb-fiber picosecond laser beam delivery, along with its use for organic material laser micro-processing.

  5. Fouling behavior of microstructured hollow fiber membranes in dead-end filtrations: Critical flux determination and NMR imaging of particle deposition

    NARCIS (Netherlands)

    Culfaz, P.Z.; Buetehorn, Steffen; Utiu, Lavinia; Kueppers, Markus; Bluemich, Bernhard; Melin, Thomas; Wessling, Matthias; Lammertink, Rob G.H.

    2011-01-01

    The fouling behavior of microstructured hollow fibers was investigated in constant flux filtrations of colloidal silica and sodium alginate. It was observed that the fouling resistance increases faster with structured fibers than with round fibers. Reversibility of structured fibers’ fouling was

  6. Fouling Behavior of Microstructured Hollow Fiber Membranes in Dead-End Filtrations: Critical Flux Determination and NMR Imaging of Particle Deposition

    NARCIS (Netherlands)

    Culfaz, P. Zeynep; Buetehorn, Steffen; Utiu, Lavinia; Kueppers, Markus; Bluemich, Bernhard; Melin, Thomas; Wessling, Matthias; Lammertink, Rob G.H.

    2011-01-01

    The fouling behavior of microstructured hollow fibers was investigated in constant flux filtrations of colloidal silica and sodium alginate. It was observed that the fouling resistance increases faster with structured fibers than with round fibers. Reversibility of structured fibers’ fouling was sim

  7. Polyethyleneimine-Functionalized Polyamide Imide (Torlon) Hollow-Fiber Sorbents for Post-Combustion CO 2 Capture

    KAUST Repository

    Li, Fuyue Stephanie

    2013-05-24

    Carbon dioxide emitted from existing coal-fired power plants is a major environmental concern due to possible links to global climate change. In this study, we expand upon previous work focused on aminosilane-functionalized polymeric hollow-fiber sorbents by introducing a new class of polyethyleneimine (PEI)-functionalized polymeric hollow-fiber sorbents for post-combustion carbon dioxide capture. Different molecular weight PEIs (Mn≈600, 1800, 10 000, and 60 000) were studied as functional groups on polyamide imide (PAI, Torlon) hollow fibers. This imide ring-opening modification introduces two amide functional groups and was confirmed by FTIR attenuated total reflectance spectroscopy. The carbon dioxide equilibrium sorption capacities of PEI-functionalized Torlon materials were characterized by using both pressure decay and gravimetric sorption methods. For equivalent PEI concentrations, PAI functionalized with lower molecular weight PEI exhibited higher carbon dioxide capacities. The effect of water in the ring-opening reaction was also studied. Up to a critical value, water in the reaction mixture enhanced the degree of functionalization of PEI to Torlon and resulted in higher carbon dioxide uptake within the functionalized material. Above the critical value, roughly 15 % w/w water, the fiber morphology was lost and the fiber was soluble in the solvent. PEI-functionalized (Mn≈600) PAI under optimal reaction conditions was observed to have the highest CO2 uptake: 4.9 g CO2 per 100 g of polymer (1.1 mmol g-1) at 0.1 bar and 35°C with dry 10 % CO2/90 % N2 feed for thermogravimetric analysis. By using water-saturated feeds (10 % CO2/90 % N2 dry basis), CO2 sorption was observed to increase to 6.0 g CO2 per 100 g of sorbent (1.4 mmol g-1). This material also demonstrated stability in cyclic adsorption-desorption operations, even under wet conditions at which some highly effective sorbents tend to lose performance. Thus, PEI-functionalized PAI fibers can be

  8. RENEWABLE FIBERS AND BIO-BASED MATERIALS FOR PACKAGING APPLICATIONS – A REVIEW OF RECENT DEVELOPMENTS

    Directory of Open Access Journals (Sweden)

    Caisa Johansson,

    2012-04-01

    Full Text Available This review describes the state-of-the-art of material derived from the forest sector with respect to its potential for use in the packaging industry. Some innovative approaches are highlighted. The aim is to cover recent developments and key challenges for successful introduction of renewable materials in the packaging market. The covered subjects are renewable fibers and bio-based polymers for use in bioplastics or as coatings for paper-based packaging materials. Current market sizes and forecasts are also presented. Competitive mechanical, thermal, and barrier properties along with material availability and ease of processing are identified as fundamental issues for sustainable utilization of renewable materials.

  9. Outer-selective pressure-retarded osmosis hollow fiber membranes from vacuum-assisted interfacial polymerization for osmotic power generation

    KAUST Repository

    Sun, Shipeng

    2013-11-19

    In this paper, we report the technical breakthroughs to synthesize outer-selective thin-film composite (TFC) hollow fiber membranes, which is in an urgent need for osmotic power generation with the pressure-retarded osmosis (PRO) process. In the first step, a defect-free thin-film composite membrane module is achieved by vacuum-assisted interfacial polymerization. The PRO performance is further enhanced by optimizing the support in terms of pore size and mechanical strength and the TFC layer with polydopamine coating and molecular engineering of the interfacial polymerization solution. The newly developed membranes can stand over 20 bar with a peak power density of 7.63 W/m2, which is equivalent to 13.72 W/m2 of its inner-selective hollow fiber counterpart with the same module size, packing density, and fiber dimensions. The study may provide insightful guidelines for optimizing the interfacial polymerization procedures and scaling up of the outer-selective TFC hollow fiber membrane modules for PRO power generation. © 2013 American Chemical Society.

  10. Structural characterization and photocatalytic activity of hollow binary ZrO 2/TiO 2 oxide fibers

    Science.gov (United States)

    Wu, Baochao; Yuan, Rusheng; Fu, Xianzhi

    2009-03-01

    The formation of hollow binary ZrO 2/TiO 2 oxide fibers using mixed precursor solutions was achieved by activated carbon fibers templating technique combined with solvothermal process. The samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), N 2 adsorption, X-ray photoelectron spectroscopy (XPS), UV-vis, and infrared (IR) spectroscopy. The binary oxide system shows the anatase-type TiO 2 and tetragonal phase of ZrO 2, and the introduction of ZrO 2 notably inhibits the growth of TiO 2 nanocrystallites. Although calcined at 575 °C, all hollow ZrO 2/TiO 2 fibers exhibit higher surface areas (>113 m 2/g) than pure TiO 2 hollow fibers. The Pyridine adsorption on ZrO 2/TiO 2 sample indicates the presence of stronger surface acid sites. Such properties bring about that the binary oxide system possesses higher efficiency and durable activity stability for photodegradation of gaseous ethylene and trichloromethane than P25 TiO 2. In addition, the macroscopic felt form for the resulting materials is more beneficial for practical applications than traditional catalysts forms.

  11. Bundled hollow optical fibers for transmission of high-peak-power Q-switched Nd:YAG laser pulses.

    Science.gov (United States)

    Yilmaz, Ozgur; Miyagi, Mitsunobu; Matsuura, Yuji

    2006-09-20

    A hollow-fiber bundle was designed and used to deliver high-peak-power pulses from a Q-switched Nd:YAG laser. An 80 cm long bundle with a total diameter of 5.5 mm was composed of 37 glass capillaries with bore diameters of 0.7 mm. Beam-resizing optics with two lenses were used to couple the laser beam into the bundle. The measured coupling loss due to the limited aperture ratio of the bundle was 2.3 dB, and the transmission loss at wavelengths of 1064 and 532 nm was 0.3 dB. When an inert gas flowed through the bores of the capillaries, the maximum output pulse energy was 200 mJ, which was the limit of the laser used in the experiment. Hollow-fiber bundles withstand irradiation better than single hollow fibers and silica-glass optical fibers do. They are suitable for many dermatological applications because they can be used to irradiate a large area.

  12. Outer-selective pressure-retarded osmosis hollow fiber membranes from vacuum-assisted interfacial polymerization for osmotic power generation.

    Science.gov (United States)

    Sun, Shi-Peng; Chung, Tai-Shung

    2013-11-19

    In this paper, we report the technical breakthroughs to synthesize outer-selective thin-film composite (TFC) hollow fiber membranes, which is in an urgent need for osmotic power generation with the pressure-retarded osmosis (PRO) process. In the first step, a defect-free thin-film composite membrane module is achieved by vacuum-assisted interfacial polymerization. The PRO performance is further enhanced by optimizing the support in terms of pore size and mechanical strength and the TFC layer with polydopamine coating and molecular engineering of the interfacial polymerization solution. The newly developed membranes can stand over 20 bar with a peak power density of 7.63 W/m(2), which is equivalent to 13.72 W/m(2) of its inner-selective hollow fiber counterpart with the same module size, packing density, and fiber dimensions. The study may provide insightful guidelines for optimizing the interfacial polymerization procedures and scaling up of the outer-selective TFC hollow fiber membrane modules for PRO power generation.

  13. A Modified EPA Method 1623 that Uses Tangential Flow Hollow-Fiber Ultrafiltration and Heat Dissociation Steps to Detect Waterborne Cryptosporidum and Giardia spp.

    Science.gov (United States)

    This protocol describes the use of a tangential flow hollow-fiber ultrafiltration sample concentration system and a heat dissociation as alternative steps for the detection of waterborne Cryptosporidium and Giardia species using EPA Method 1623.

  14. DEMONSTRATION OF PILOT-SCALE PERVAPORATION SYSTEMS FOR VOLATILE ORGANIC COMPOUND REMOVAL FROM A SURFACTANT ENHANCED AQUIFER REMEDIATION FLUID. II. HOLLOW FIBER MEMBRANE MODULES

    Science.gov (United States)

    Pilot-scale demonstration of pervaporation-based removal of volatile organic compounds from a surfactant enhanced aquifer remediation (SEAR) fluid has been conducted at USEPA's Test & Evaluation Facility using hollow fiber membrane modules. The membranes consisted of microporous...

  15. Hollow Fiber Spacesuit Water Membrane Evaporator Development and Testing for Advanced Spacesuits

    Science.gov (United States)

    Bue, Grant C.; Trevino, Luis A.; Tsioulos, Gus; Settles, Joseph; Colunga, Aaron; Vogel, Matthew; Vonau, Walt

    2010-01-01

    The spacesuit water membrane evaporator (SWME) is being developed to perform the thermal control function for advanced spacesuits to take advantage of recent advances in micropore membrane technology in providing a robust heat-rejection device that is potentially less sensitive to contamination than is the sublimator. Principles of a sheet membrane SWME design were demonstrated using a prototypic test article that was tested in a vacuum chamber at JSC in July 1999. The Membrana Celgard X50-215 microporous hollow fiber (HoFi) membrane was selected after recent contamination tests as the most suitable candidate among commercial alternatives for HoFi SWME prototype development. A design that grouped the fiber layers into stacks, which were separated by small spaces and packaged into a cylindrical shape, was developed into a full-scale prototype consisting 14,300 tube bundled into 30 stacks, each of which are formed into a chevron shape and separated by spacers and organized into three sectors of ten nested stacks. Vacuum chamber testing has been performed characterize heat rejection as a function of inlet water temperature and water vapor backpressure and to show contamination resistance to the constituents expected to be found in potable water produced by the distillation processes. Other tests showed the tolerance to freezing and suitability to reject heat in a Mars pressure environment.

  16. Analysis of ammonia separation from purge gases in microporous hollow fiber membrane contactors.

    Science.gov (United States)

    Karami, M R; Keshavarz, P; Khorram, M; Mehdipour, M

    2013-09-15

    In this study, a mathematical model was developed to analyze the separation of ammonia from the purge gas of ammonia plants using microporous hollow fiber membrane contactors. A numerical procedure was proposed to solve the simultaneous linear and non linear partial differential equations in the liquid, membrane and gas phases for non-wetted or partially wetted conditions. An equation of state was applied in the model instead of Henry's law because of high solubility of ammonia in water. The experimental data of CO₂-water system in the literature was used to validate the model due to the lack of data for ammonia-water system. The model showed that the membrane contactor can separate ammonia very effectively and with recoveries higher than 99%. SEM images demonstrated that ammonia caused some micro-cracks on the surfaces of polypropylene fibers, which could be an indication of partial wetting of membrane in long term applications. However, the model results revealed that the membrane wetting did not have significant effect on the absorption of ammonia because of very high solubility of ammonia in water. It was also found that the effect of gas velocity on the absorption flux was much more than the effect of liquid velocity.

  17. Mathematical modeling of liquid/liquid hollow fiber membrane contactor accounting for interfacial transport phenomena: Extraction of lanthanides as a surrogate for actinides

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, J.D.

    1994-08-04

    This report is divided into two parts. The second part is divided into the following sections: experimental protocol; modeling the hollow fiber extractor using film theory; Graetz model of the hollow fiber membrane process; fundamental diffusive-kinetic model; and diffusive liquid membrane device-a rigorous model. The first part is divided into: membrane and membrane process-a concept; metal extraction; kinetics of metal extraction; modeling the membrane contactor; and interfacial phenomenon-boundary conditions-applied to membrane transport.

  18. Guiding and concentrating hard x-rays by using a flexible hollow-core tapered glass fiber.

    Science.gov (United States)

    Thiel, D J; Bilderback, D H; Lewis, A; Stern, E A; Rich, T

    1992-03-01

    A 1.6-m-long, flexible, hollow glass fiber with a gradually diminishing bore diameter has been used efficiently to compress the size of an x-ray beam as it reflects from the inside walls of the fiber by total external reflection. The transmission characteristics of the fiber are reported for monochromatic synchrotron radiation of 8.04, 13, and 20 keV, as well as for CuKalpha radiation from a conventional x-ray tube. Intensity enhancements as large as 10 that correspond to a transmission efficiency of 54% were observed. The high efficiency of this prototype fiber supports the idea that this confinement technique should yield intensity gains of many orders of magnitude as the optimal fiber design is achieved.

  19. Incompressible laminar flow through hollow fibers: a general study by means of a two-scale approach

    Science.gov (United States)

    Borsi, Iacopo; Farina, Angiolo; Fasano, Antonio

    2011-08-01

    We study the laminar flow of an incompressible Newtonian fluid in a hollow fiber, whose walls are porous. We write the Navier-Stokes equations for the flow in the inner channel and Darcy's law for the flow in the fiber, coupling them by means of the Beavers-Joseph condition which accounts for the (possible) slip at the membrane surface. Then, we introduce a small parameter {\\varepsilon ≪ 1} (the ratio between the radius and the length of the fiber) and expand all relevant quantities in powers of ɛ. Averaging over the fiber cross section, we find the velocity profiles for the longitudinal flow and for the cross-flow, and eventually, we determine the explicit expression of the permeability of the system. This work is also preliminary to the study of more complex systems comprising a large number of identical fibers (e.g., ultrafiltration modules and dialysis).

  20. Design and fabrication of hollow-core photonic crystal fibers for high power fast laser beam transportation and pulse compression

    Science.gov (United States)

    Wang, Y. Y.; Peng, Xiang; Alharbi, M.; Dutin, C. F.; Bradley, T. D.; Mielke, Michael; Booth, Timothy; Benabid, F.

    2012-03-01

    We report on recent design and fabrication of Kagome type hollow-core photonic crystal fiber (HC-PCF) for the purpose of high power fast laser beam transportation. The fabricated seven-cell three-ring hypocycloid-shaped large core fiber exhibits an up-to-date lowest attenuation (among all Kagome fibers) of 40dB/km over a broadband transmission centered at 1500nm. We show that the large core size, low attenuation, broadband transmission, single modedness, low dispersion and relatively low banding loss makes it an ideal host for high power laser beam transportation. By filling the fiber with helium gas, a 74μJ, 850fs and 40kHz repetition rate ultra-short pulse at 1550nm has been faithfully delivered with little propagation pulse distortion. Compression of a 105μJ laser pulse from 850fs to 300fs has been achieved by operating the fiber in ambient air.

  1. Enhanced chemiluminescent detection scheme for trace vapor sensing in pneumatically-tuned hollow core photonic bandgap fibers.

    Science.gov (United States)

    Stolyarov, Alexander M; Gumennik, Alexander; McDaniel, William; Shapira, Ofer; Schell, Brent; Sorin, Fabien; Kuriki, Ken; Benoit, Gilles; Rose, Aimee; Joannopoulos, John D; Fink, Yoel

    2012-05-21

    We demonstrate an in-fiber gas phase chemical detection architecture in which a chemiluminescent (CL) reaction is spatially and spectrally matched to the core modes of hollow photonic bandgap (PBG) fibers in order to enhance detection efficiency. A peroxide-sensitive CL material is annularly shaped and centered within the fiber's hollow core, thereby increasing the overlap between the emission intensity and the intensity distribution of the low-loss fiber modes. This configuration improves the sensitivity by 0.9 dB/cm compared to coating the material directly on the inner fiber surface, where coupling to both higher loss core modes and cladding modes is enhanced. By integrating the former configuration with a custom-built optofluidic system designed for concomitant controlled vapor delivery and emission measurement, we achieve a limit-of-detection of 100 parts per billion (ppb) for hydrogen peroxide vapor. The PBG fibers are produced by a new fabrication method whereby external gas pressure is used as a control knob to actively tune the transmission bandgaps through the entire visible range during the thermal drawing process.

  2. Hollow Fiber Flight Prototype Spacesuit Water Membrane Evaporator Design and Testing

    Science.gov (United States)

    Bue, Grant; Vogel, Matt; Makinen, Janice; Tsioulos, Gus

    2010-01-01

    The spacesuit water membrane evaporator (SWME) is being developed to perform thermal control for advanced spacesuits and to take advantage of recent advances in micropore membrane technology. This results in a robust heat-rejection device that is potentially less sensitive to contamination than is the sublimator. The Membrana Celgard X50-215 microporous hollow-fiber (HoFi) membrane was selected after recent extensive testing as the most suitable candidate among commercial alternatives for continued SWME prototype development. The current design was based on a previous design that grouped the fiber layers into stacks, which were separated by small spaces and packaged into a cylindrical shape. This was developed into a full-scale prototype consisting of 14,300 tube bundled into 30 stacks, each of which is formed into a chevron shape and separated by spacers and organized into three sectors of 10 nested stacks. The new design replaced metal components with plastic ones, and has a custom built flight like backpressure valve mounted on the side of the SWME housing to reduce backpressure when fully open. The spacers that provided separation of the chevron fiber stacks were eliminated. Vacuum chamber testing showed improved heat rejection as a function of inlet water temperature and water vapor backpressure compared with the previous design. Other tests pushed the limits of tolerance to freezing and showed suitability to reject heat in a Mars pressure environment with and without a sweep gas. Tolerance to contamination by constituents expected to be found in potable water produced by distillation processes was tested in a conventional way by allowing constituents to accumulate in the coolant as evaporation occurs. For this purpose, the SWME cartridge has endured an equivalent of 30 EVAs exposure and demonstrated minimal performance decline.

  3. Development of a High Performance PES Ultrafiltration Hollow Fiber Membrane for Oily Wastewater Treatment Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Noor Adila Aluwi Shakir

    2015-12-01

    Full Text Available This study attempts to optimize the spinning process used for fabricating hollow fiber membranes using the response surface methodology (RSM. The spinning factors considered for the experimental design are the dope extrusion rate (DER, air gap length (AGL, coagulation bath temperature (CBT, bore fluid ratio (BFR, and post-treatment time (PT whilst the response investigated is rejection. The optimal spinning conditions promising the high rejection performance of polyethersulfone (PES ultrafiltration hollow fiber membranes for oily wastewater treatment are at the dope extrusion rate of 2.13 cm3/min, air gap length of 0 cm, coagulation bath temperature of 30 °C, and bore fluid ratio (NMP/H2O of 0.01/99.99 wt %. This study will ultimately enable the membrane fabricators to produce high-performance membranes that contribute towards the availability of a more sustainable water supply system.

  4. Modification of spontaneous emission rate of micrometer-sized light sources using hollow-core photonic crystal fibers

    Institute of Scientific and Technical Information of China (English)

    Lu Jiao-Hua; Meng Zi-Ming; Liu Hai-Ying; Feng Tian-Hua; Dai Qiao-Feng; Wu Li-Jun; Gun Qi; Hu Wei; Lan Sheng

    2009-01-01

    We investigate numerically and experimentally the modification of the spontaneous emission rate for micrometer. sized light sources embedded in a hollow-core photonic crystal fiber(HCPCF). The diameter of the light source is deliberately chosen such that they could be easily introduced into the central hole of the hollow-core photonic crystal fiber by canillary force. The photoluminescence from the microparticles is measured by using an inverted microscope in combination with a spectrometer. The modification of the spontaneous emission rate is observed in a wavelength region where there is no band gap. The experimental observations are consistent with the simulation results obtained by the plane wave expansion and finite-difference time-domain techniques.

  5. Monosaccharide composition analysis of immunomodulatory polysaccharides by on-line hollow fiber microextraction with high-performance liquid chromatography.

    Science.gov (United States)

    Wang, Nani; Wang, Xuping; Huang, Xiaowen; Mao, Zhujun; Zhang, Yang; Yu, Yong; Shou, Dan

    2016-03-01

    The monosaccharide compositions of functional polysaccharides are essential for structure elucidation and biological activity determination. A sensitive method based on on-line hollow-fiber liquid-phase microextraction with high-performance liquid chromatography has been established for the analysis of ten monosaccharide compositions (two uronic acids, two amino sugars and six neutral sugars) of the immunomodulatory polysaccharides. After derivatization, the sample was injected into the lumen of a hollow fiber immersed in butyl ether and separated by liquid chromatography. Under optimized conditions, the calibration curves were linear (r ≥ 0.9996) in the range of 10-2000 μmol L(-1) . The limits of detection were in the range of 0.04-1.58 μmol L(-1) , and the recoveries were in the range of 92.1-99.6%, which shows that the method is applicable to the analysis of the monosaccharide composition of various polysaccharides.

  6. Ultrahigh and persistent optical depths of cesium in Kagomé-type hollow-core photonic crystal fibers.

    Science.gov (United States)

    Kaczmarek, Krzysztof T; Saunders, Dylan J; Sprague, Michael R; Kolthammer, W Steven; Feizpour, Amir; Ledingham, Patrick M; Brecht, Benjamin; Poem, Eilon; Walmsley, Ian A; Nunn, Joshua

    2015-12-01

    Alkali-filled hollow-core fibers are a promising medium for investigating light-matter interactions, especially at the single-photon level, due to the tight confinement of light and high optical depths achievable by light-induced atomic desorption (LIAD). However, until now these large optical depths could only be generated for seconds, at most once per day, severely limiting the practicality of the technology. Here we report the generation of the highest observed transient (>10(5) for up to a minute) and highest observed persistent (>2000 for hours) optical depths of alkali vapors in a light-guiding geometry to date, using a cesium-filled Kagomé-type hollow-core photonic crystal fiber (HC-PCF). Our results pave the way to light-matter interaction experiments in confined geometries requiring long operation times and large atomic number densities, such as generation of single-photon-level nonlinearities and development of single photon quantum memories.

  7. Blood glucose measurement in vivo using hollow-fiber based, mid-infrared ATR probe with multi-reflection prism

    Science.gov (United States)

    Kino, Saiko; Omori, Suguru; Matsuura, Yuji

    2016-03-01

    An attenuated-total-reflection (ATR), mid-infrared spectroscopy system that consists of hollow optical fibers, a trapezoidal multi-reflection ATR prism, and a conventional FT-IR spectrometer has been developed to measure blood glucose levels. Owing to the low transmission loss and high flexibility of the hollow-optical fiber, the system can measure any sites of the human body where blood capillaries are close to the surface of mucosa, such as inner lips. Using a multi-reflection prism brought about higher sensitivity, and the flat and wide contact surface of the prism resulted in higher measurement reproducibility. The results of in-vivo measurement of human inner lips showed the feasibility of the proposed system, and the measurement errors were within 20%.

  8. Spinning process variables and polymer solution effects in the die-swell phenomenon during hollow fiber membranes formation

    Directory of Open Access Journals (Sweden)

    Pereira C.C.

    2000-01-01

    Full Text Available During hollow fiber spinning many variables are involved whose effects are still not completely clear. However, its understanding is of great interest because the control of these variables may originate membranes with the desired morphologies and physical properties. In this work, the phase inversion process induced by the immersion precipitation technique was applied to prepare hollow fibers membranes. It was verified that some of the variables involved, can promote a visco-elastic polymer solution expansion, called die-swell phenomenon, which is undesired since it may lead to low reproducibility of the permeation properties. The effects of the distance between spinneret and precipitation bath, the bore liquid composition, and the polymer solution composition were analyzed and discussed in order to avoid this phenomenon. According to the results, it was verified that the parameters investigated might promote a delay precipitation, which restrained the visco-elastic expansion.

  9. THE ROLE OF POROUS MEDIA IN MODELING FLUID FLOW WITHIN HOLLOW FIBER MEMBRANES OF THE TOTAL ARTIFICIAL LUNG.

    Science.gov (United States)

    Khanafer, Khalil; Cook, Keith; Marafie, Alia

    2012-01-01

    A numerical study was conducted to analyze fluid flow within hollow fiber membranes of the artificial lungs. The hollow fiber bundle was approximated using a porous media model. In addition, the transport equations were solved using the finite-element formulation based on the Galerkin method of weighted residuals. Comparisons with previously published work on the basis of special cases were performed and found to be in excellent agreement. A Newtonian viscous fluid model for the blood was used. Different flow models for porous media, such as the Brinkman-extended Darcy model, Darcy's law model, and the generalized flow model, were considered. Results were obtained in terms of streamlines, velocity vectors, and pressure distribution for various Reynolds numbers and Darcy numbers. The results from this investigation showed that the pressure drop across the artificial lung device increased with an increase in the Reynolds number. In addition, the pressure drop was found to increase significantly for small Darcy numbers.

  10. Foulant analysis of hollow fine fiber (HFF) membranes in Red Sea SWRO plants using membrane punch autopsy (MPA)

    KAUST Repository

    Green, Troy N.

    2017-06-12

    Membrane punch autopsy (MPA) is a procedure for quantitative foulant analysis of hollow fine fiber (HFF) permeators. In the past, quantitative autopsies of membranes were restricted to spiral wound. This procedure was developed at SWCC laboratories and tested on permeators of two commercial Red Sea reverse osmosis plants. For membrane autopsies, stainless steel hollow bore picks were penetrated to membrane cores and fibers extracted for foulant analysis. Quantitative analysis of extracted materials contained inorganic and organic foulants including bacteria. Fourier transform infrared spectroscopy analysis confirmed the presence of organic fouling functional groups and scanning electron microscopy with energy dispersive X-ray spectroscopy in the presence of diatoms and silica most likely not from particulate sand. API analysis revealed the presence of Shewanella and two Vibrio microbial species confirmed by 16S rDNA sequence library. It was observed that fouling content of HFF cellulose triacetate (CTA) membranes were more than 800 times than polyamide spiral wound membranes.

  11. Selective interfacial synthesis of metal-organic frameworks on a polybenzimidazole hollow fiber membrane for gas separation.

    Science.gov (United States)

    Biswal, Bishnu P; Bhaskar, Anand; Banerjee, Rahul; Kharul, Ulhas K

    2015-04-28

    Metal-organic frameworks (MOFs) have gained immense attention as new age materials due to their tuneable properties and diverse applicability. However, efforts on developing promising materials for membrane based gas separation, and control over the crystal growth positions on polymeric hollow fiber membranes still remain key challenges. In this investigation, a new, convenient and scalable room temperature interfacial method for growing MOFs (ZIF-8 and CuBTC) on either the outer or inner side of a polybenzimidazole based hollow fiber (PBI-BuI-HF) membrane surface has been achieved in a controlled manner. This was made possible by the appropriate selection of an immiscible solvent pair and the synthetic conditions. The growth of MOFs on the PBI-BuI-HF membrane by the interfacial method was continuous and showed an appreciable gas separation performance, conveying promise for their applicability.

  12. Relationship between Ceftolozane-Tazobactam Exposure and Selection for Pseudomonas aeruginosa Resistance in a Hollow-Fiber Infection Model

    OpenAIRE

    VanScoy, Brian D.; Mendes, Rodrigo E.; Castanheira, Mariana; McCauley, Jennifer; Bhavnani, Sujata M.; Jones, Ronald N.; Friedrich, Lawrence V.; Steenbergen, Judith N.; Ambrose, Paul G.

    2014-01-01

    It is important to understand the relationship between antibiotic exposure and the selection of drug resistance in the context of therapy exposure. We sought to identify the ceftolozane-tazobactam exposure necessary to prevent the amplification of drug-resistant bacterial subpopulations in a hollow-fiber infection model. Two Pseudomonas aeruginosa challenge isolates were selected for study, a wild-type ATCC strain (ceftolozane-tazobactam MIC, 0.5 mg/liter) and a clinical isolate (ceftolozane-...

  13. High-performance, anode-supported, microtubular SOFC prepared from single-step-fabricated, dual-layer hollow fibers

    Energy Technology Data Exchange (ETDEWEB)

    Othman, Mohd Hafiz Dzarfan; Droushiotis, Nicolas; Wu, Zhentao; Kelsall, Geoff; Li, Kang [Department of Chemical Engineering, Imperial College London, London SW7 2AZ (United Kingdom)

    2011-06-03

    A high-performance, microtubular solid oxide fuel cell is developed using an improved electrolyte/anode dual-layer hollow fiber fabricated via a novel coextrusion and co-sintering technique. The technique allows control over the porosity of the anode, resulting in an increase in the power output to almost double what has been previously reported. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Development of Polysulfone Hollow Fiber Porous Supports for High Flux Composite Membranes: Air Plasma and Piranha Etching

    OpenAIRE

    Ilya Borisov; Anna Ovcharova; Danila Bakhtin; Stepan Bazhenov; Alexey Volkov; Rustem Ibragimov; Rustem Gallyamov; Galina Bondarenko; Rais Mozhchil; Alexandr Bildyukevich; Vladimir Volkov

    2017-01-01

    For the development of high efficiency porous supports for composite membrane preparation, polysulfone (PSf) hollow fiber membranes (outer diameter 1.57 mm, inner diameter 1.12 mm) were modified by air plasma using the low temperature plasma treatment pilot plant which is easily scalable to industrial level and the Piranha etch (H2O2 + H2SO4). Chemical and plasma modification affected only surface layers and did not cause PSf chemical structure change. The modifications led to surface roughne...

  15. Extremely Nonlinear Optics Using Shaped Pulses Spectrally Broadened in an Argon- or Sulfur Hexafluoride-Filled Hollow-Core Fiber

    OpenAIRE

    Andreas Hoffmann; Michael Zürch; Christian Spielmann

    2015-01-01

    In this contribution we present a comparison of the performance of spectrally broadened ultrashort pulses using a hollow-core fiber either filled with argon or sulfur hexafluoride (SF6) for demanding pulse-shaping experiments. The benefits of both gases for pulse-shaping are studied in the highly nonlinear process of high-harmonic generation. In this setup, temporally shaping the driving laser pulse leads to spectrally shaping of the output extreme ultraviolet (XUV) spectrum, where total yie...

  16. Soliton delivery of few-cycle optical gigawatt pulses in Kagome-lattice hollow-core photonic crystal fibers

    Science.gov (United States)

    Im, Song-Jin; Husakou, Anton; Herrmann, Joachim

    2010-08-01

    We study the delivery of few-cycle soliton-like pulses at 800 nm with gigawatt power or microjoule energy through a hollow-core kagome-lattice photonic crystal fiber over 1 m with preserved temporal and spectral shape. We show that with optimized pressure of the argon filling, 5 fs input pulses are compressed up to 2.5 fs after 20 cm and restore their shape after 1 m propagation.

  17. Renewable fibers and bio-based materials for packaging applications - A review of recent developments

    DEFF Research Database (Denmark)

    Johansson, Caisa; Bras, Julien; Mondragon, Inaki

    2012-01-01

    materials in the packaging market. The covered subjects are renewable fibers and bio-based polymers for use in bioplastics or as coatings for paper-based packaging materials. Current market sizes and forecasts are also presented. Competitive mechanical, thermal, and barrier properties along with material...

  18. A Raman cell based on hollow core photonic crystal fiber for human breath analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chow, Kam Kong; Zeng, Haishan, E-mail: hzeng@bccrc.ca [Imaging Unit – Integrative Oncology Department, British Columbia Cancer Agency Research Centre, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3, Canada and Medical Physics Program – Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1 (Canada); Short, Michael; Lam, Stephen; McWilliams, Annette [Imaging Unit – Integrative Oncology Department, British Columbia Cancer Agency Research Centre, 675 West 10th Avenue, Vancouver, British Columbia V5Z 1L3 (Canada)

    2014-09-15

    Purpose: Breath analysis has a potential prospect to benefit the medical field based on its perceived advantages to become a point-of-care, easy to use, and cost-effective technology. Early studies done by mass spectrometry show that volatile organic compounds from human breath can represent certain disease states of our bodies, such as lung cancer, and revealed the potential of breath analysis. But mass spectrometry is costly and has slow-turnaround time. The authors’ goal is to develop a more portable and cost effective device based on Raman spectroscopy and hollow core-photonic crystal fiber (HC-PCF) for breath analysis. Methods: Raman scattering is a photon-molecular interaction based on the kinetic modes of an analyte which offers unique fingerprint type signals that allow molecular identification. HC-PCF is a novel light guide which allows light to be confined in a hollow core and it can be filled with a gaseous sample. Raman signals generated by the gaseous sample (i.e., human breath) can be guided and collected effectively for spectral analysis. Results: A Raman-cell based on HC-PCF in the near infrared wavelength range was developed and tested in a single pass forward-scattering mode for different gaseous samples. Raman spectra were obtained successfully from reference gases (hydrogen, oxygen, carbon dioxide gases), ambient air, and a human breath sample. The calculated minimum detectable concentration of this system was ∼15 parts per million by volume, determined by measuring the carbon dioxide concentration in ambient air via the characteristic Raman peaks at 1286 and 1388 cm{sup −1}. Conclusions: The results of this study were compared to a previous study using HC-PCF to trap industrial gases and backward-scatter 514.5 nm light from them. The authors found that the method presented in this paper has an advantage to enhance the signal-to-noise ratio (SNR). This SNR advantage, coupled with the better transmission of HC-PCF in the near-IR than in the

  19. Continuous Wave Stimulated Raman Spectroscopy Inside a Hollow Core Photonic Crystal Fiber

    Science.gov (United States)

    Domenech, Jose L.; Cueto, Maite

    2013-06-01

    Hollow-core photonic crystal fibers (HCPCF) have raised new opportunities to study light-matter interaction. Dielectric or metallic capillaries are intrinsically lossy, making poor light guides. In contrast, HCPCFs can guide light quite efficiently, due to the band-gap effect produced by an array of smaller channels which surrounds a central hollow core with a few μm diameter. The tight confinement of light inside the core, that can be filled with gases, as well as a long interaction length, enhance multiple nonlinear phenomena, making it possible to devise new ways to do low signal level spectroscopy, as is the case of high resolution stimulated Raman spectroscopy (SRS). A. Owyoung demonstrated high resolution continuous wave SRS in 1978. Shortly afterwards, seeking higher sensitivity, he developed the quasi-continuous SRS technique (a high peak power pump laser, interacting with a low power cw probe laser). That variant remains today the best compromise between resolution and sensitivity for gas-phase Raman spectroscopy. In this work, we show the possibility of fully cw stimulated Raman spectroscopy, using a gas cell built around a HCPCF to overcome the limitations posed by the weakness of the stimulated Raman effect when not using pulsed sources. The interaction length (1.2 m), longer than that of a multiple pass refocusing cell, and the narrow diameter of the core (4.8 μm), can compensate for the much lower laser powers used in the cw set-up. The experimental complexity is considerably reduced and the instrumental resolution is at the 10's of MHz level, limited, with our fiber, by transit time effects. At present, we have demonstrated the feasibility of the experiment, a sensitivity enhancement of ˜ 6000 over the single focus regime, and a spectral resolution better than 0.005 wn in the unresolved Q-branch of the ν_1 component of the Fermi dyad of CO_2 at 1388 wn. Other examples of rotationally resolved spectra will be shown: the Q branch of O_2 at 1555 wn

  20. Pressure retarded osmosis dual-layer hollow fiber membranes developed by co-casting method and ammonium persulfate (APS) treatment

    KAUST Repository

    Fu, Fengjiang

    2014-11-01

    Delamination and low water permeability are two issues limiting the applications of dual-layer hollow fiber membranes in the pressure retarded osmosis (PRO) process. In this work, we first developed a universal co-casting method that is able to co-cast highly viscous dope solutions to form homogeneous dual-layer flat sheet membranes. By employing this method prior to the tedious dual-layer hollow fiber spinning process, both time and material consumptions are significantly saved. The addition of polyvinylpyrrolidone (PVP) is found to eliminate delamination at the sacrifice of water flux. A new post-treatment method that involves flowing ammonium persulfate (APS) solution and DI water counter-currently is potentially to remove the PVP molecules entrapped in the substrate while keeps the integrity of the interface. As the APS concentration increases, the water flux in the PRO process is increased while the salt leakage is slightly decreased. With the optimized APS concentration of 5wt%, the post-treated membrane shows a maximum power density of 5.10W/m2 at a hydraulic pressure of 15.0bar when 1M NaCl and 10mM NaCl were used as the draw and feed solutions, respectively. To the extent of our knowledge, this is the best phase inversion dual-layer hollow fiber membrane with an outer selective layer for osmotic power generation. © 2014 Elsevier B.V.

  1. Osmotic Power Generation by Inner Selective Hollow Fiber Membranes: An investigation of thermodynamics, mass transfer, and module scale modelling

    KAUST Repository

    Xiong, Jun Ying

    2016-12-29

    A comprehensive analysis of fluid motion, mass transport, thermodynamics and power generation during pressure retarded osmotic (PRO) processes was conducted. This work aims to (1) elucidate the fundamental relationship among various membrane properties and operation parameters and (2) analyse their individual and combined impacts on PRO module performance. A state-of-the-art inner-selective thin-film composite (TFC) hollow fiber membrane was employed in the modelling. The analyses of mass transfer and Gibbs free energy of mixing indicate that the asymmetric nature of hollow fibers results in more significant external concentration polarization (ECP) in the lumen side of the inner-selective hollow fiber membranes. In addition, a trade-off relationship exists between the power density (PD) and the specific energy (SE). The PD vs. SE trade-off upper bound may provide a useful guidance whether the flowrates of the feed and draw solutions should be further optimized in order to (1) minimize the boundary thickness and (2) maximize the osmotic power generation. Two new terms, mass transfer efficiency and power harvesting efficiency for osmotic power generation, have been proposed. This work may provide useful insights to design and operate PRO modules with enhanced performance so that the PRO process becomes more promising in real applications in the near future.

  2. Fabrication of a rugged polymer-coated silver hollow fiber with a vitreous film for the infrared

    Science.gov (United States)

    Iwai, Katsumasa; Miyagi, Mitsunobu; Shi, Yi-Wei; Matsuura, Yuji

    2013-03-01

    A rugged hollow fiber is fabricated by liquid-phase coating techniques. A silica glass capillary is used as the substrate and a vitreous film is firstly coated on the inner surface of the capillary to protect the glass tube from moisture. This protective coating keeps the thin-wall glass tube away from damage due to the following silver plating process. On the protective coating, a silver film is deposited by the conventional mirror plating technique. Subsequently, a polymer film is coated on the silver film to reduce transmission loss by employing interference effect of the polymer film. Fabrication processes and transmission properties of the rugged polymer-coated silver hollow fiber were discussed. The loss for the 700-μm-bore size, 1-m-length hollow fiber was 2 dB under straight configuration, and 3.5 dB under the configuration of a 270 degree bending with a 15-mm bending radius at the wavelength of 2.94 μm.

  3. Single mode operation with mid-IR hollow fibers in the range 5.1-10.5 µm.

    Science.gov (United States)

    Sampaolo, Angelo; Patimisco, Pietro; Kriesel, Jason M; Tittel, Frank K; Scamarcio, Gaetano; Spagnolo, Vincenzo

    2015-01-12

    Single mode beam delivery in the mid-infrared spectral range 5.1-10.5 μm employing flexible hollow glass waveguides of 15 cm and 50 cm lengths, with metallic/dielectric internal layers and a bore diameter of 200 μm were demonstrated. Three quantum cascade lasers were coupled with the hollow core fibers. For a fiber length of 15 cm, we measured losses down to 1.55 dB at 5.4 μm and 0.9 dB at 10.5 μm. The influence of the launch conditions in the fiber on the propagation losses and on the beam profile at the waveguide exit was analyzed. At 10.5 µm laser wavelength we found near perfect agreement between measured and theoretical losses, while at ~5 µm and ~6 µm wavelengths the losses were higher than expected. This discrepancy can be explained considering an additional scattering loss effect, which scales as 1/λ(2) and is due to surface roughness of the metallic layer used to form the high-reflective internal layer structure of the hollow core waveguide.

  4. Hollow-fiber micro-extraction combined with HPLC for the determination of sitagliptin in urine samples

    Directory of Open Access Journals (Sweden)

    Rezaee Raheme

    2015-01-01

    Full Text Available This study successfully developed a three-phase hollow-fiber liquid phase micro extraction coupled with high performance liquid chromatography for determination of trace levels of an anti-diabetic drug, sitagliptin (STG, in urine samples. Sitagliptin was extracted from 15 mL of the basic sample solution with a pH of 8.5 into an organic extracting solvent (n-octanol impregnated in the pores of a hollow fiber and then back extracted into an acidified aqueous solution in the lumen of the hollow fiber with a pH of 3. After extraction, 20 µL of the acceptor phase was injected into HPLC. In order to obtain high extraction efficiency, the parameters affecting the HF-LPME including pH of the source and receiving phases, type of organic phase, ionic strength, stirring rate, extraction time, the volume ratio of donor phase to acceptor phase and temperature were studied and optimized. Under the optimized conditions, enrichment factors up to 88 were achieved and the relative standard deviation of the method was in the range of 3 % to 6%. The results indicated that HF-LPME method has an excellent clean-up capacity and a high preconcentration factor and can serve as a simple and sensitive method for monitoring the drug in the urine samples.

  5. Synthesis of ceramic hollow fiber supported zeolitic imidazolate framework-8 (ZIF-8) membranes with high hydrogen permeability

    KAUST Repository

    Pan, Yichang

    2012-12-01

    Purification and recovery of hydrogen from hydrocarbons in refinery streams in the petrochemical industry is an emerging research field in the study of membrane gas separation. Hollow fiber membrane modules can be easily implemented into separation processes at the industrial scale. In this report, hollow yttria-stabilized zirconia (YSZ) fiber-supported zeolitic imidazole framework-8 (ZIF-8) membranes were successfully prepared using a mild and environmentally friendly seeded growth method. Our single-component permeation studies demonstrated that the membrane had a very high hydrogen permeance (~15×10 -7mol/m 2sPa) and an ideal selectivity of H 2/C 3H 8 of more than 1000 at room temperature. This high membrane permeability and selectivity caused serious concentration polarization in the separation of H 2/C 3H 8 mixtures, which led to almost 50% drop in both the H 2 permeance and the separation factor. Enhanced mixing on the feed side could reduce the effect of the concentration polarization. Our experimental data also indicated that the membranes had excellent reproducibility and long-term stability, indicating that the hollow fiber-supported ZIF-8 membranes developed in this study have great potential in industry-scale separation of hydrogen. © 2012 Elsevier B.V.

  6. High-sensitivity molecular sensing using hollow-core photonic crystal fiber and surface-enhanced Raman scattering.

    Science.gov (United States)

    Yang, Xuan; Shi, Chao; Wheeler, Damon; Newhouse, Rebecca; Chen, Bin; Zhang, Jin Z; Gu, Claire

    2010-05-01

    A high-sensitivity molecular sensor using a hollow-core photonic crystal fiber (HCPCF) based on surface-enhanced Raman scattering (SERS) has been experimentally demonstrated and theoretically analyzed. A factor of 100 in sensitivity enhancement is shown in comparison to direct sampling under the same conditions. With a silver nanoparticle colloid as the SERS substrate and Rhodamine 6G as a test molecule, the lowest detectable concentration is 10(-10) M with a liquid-core photonic crystal fiber (LCPCF) probe, and 10(-8) M for direct sampling. The high sensitivity provided by the LCPCF SERS probe is promising for molecular detection in various sensing applications.

  7. Soliton self-frequency blue-shift in gas-filled hollow-core photonic crystal fibers

    OpenAIRE

    2011-01-01

    We show theoretically that the photoionization process in a hollow-core photonic crystal fiber filled with a Raman-inactive noble gas leads to a constant acceleration of solitons in the time domain with a continuous shift to higher frequencies, limited only by ionization loss. This phenomenon is opposite to the well-known Raman self-frequency red-shift of solitons in solid-core glass fibers. We also predict the existence of unconventional long-range non-local soliton interactions leading to s...

  8. Picosecond and nanosecond pulse delivery through a hollow-core Negative Curvature Fiber for micro-machining applications.

    Science.gov (United States)

    Jaworski, Piotr; Yu, Fei; Maier, Robert R J; Wadsworth, William J; Knight, Jonathan C; Shephard, Jonathan D; Hand, Duncan P

    2013-09-23

    We present high average power picosecond and nanosecond pulse delivery at 1030 nm and 1064 nm wavelengths respectively through a novel hollow-core Negative Curvature Fiber (NCF) for high-precision micro-machining applications. Picosecond pulses with an average power above 36 W and energies of 92 µJ, corresponding to a peak power density of 1.5 TWcm⁻² have been transmitted through the fiber without introducing any damage to the input and output fiber end-faces. High-energy nanosecond pulses (>1 mJ), which are ideal for micro-machining have been successfully delivered through the NCF with a coupling efficiency of 92%. Picosecond and nanosecond pulse delivery have been demonstrated in fiber-based laser micro-machining of fused silica, aluminum and titanium.

  9. Analytical formulation for the bend-loss in single-ring hollow-core photonic crystal fibers

    CERN Document Server

    Frosz, Michael H; Günendi, Mehmet C; Russell, Philip St J

    2016-01-01

    Understanding bend-loss in single-ring hollow-core photonic crystal fibers is becoming of increasing importance as the fibers enter practical applications. While purely numerical approaches are useful, there is a need for a simpler analytical formalism that provides physical insight and can be directly used in the design of PCFs with low bend-loss. We show theoretically and experimentally that a wavelength-dependent critical bend radius exists below which the bend-loss reaches a maximum, and that this can be calculated from the structural parameters of a fiber using a simple analytical formula. This allows straightforward design of single-ring PCFs that are bend-insensitive for specified ranges of bend radius and wavelength. It also can be used to derive an expression for the bend radius that yields optimal higher-order mode suppression for a given fiber structure.

  10. Fiber optic probes based on silver-only coated hollow glass waveguides for ionizing beam radiation dosimetry

    Science.gov (United States)

    Darafsheh, Arash; Liu, Haoyang; Melzer, Jeffrey E.; Taleei, Reza; Harrington, James A.; Kassaee, Alireza; Zhu, Timothy C.; Finlay, Jarod C.

    2016-03-01

    Čerenkov contamination is a significant issue in radiation detection by fiber-coupled scintillators. To enhance the scintillation signal transmission while minimizing Čerenkov contamination, we designed a fiber probe using a silver-only coated hollow waveguide (HWG). The HWG tip with inserted scintillator, embedded in tissue mimicking phantoms, was irradiated with clinical electron and photon beams. Optical spectra of irradiated tips were taken using a fiber spectrometer, and the signal was deconvolved with a linear fitting algorithm. The resultant decomposed spectra of the scintillator with and without Čerenkov correction were in good agreement with measurements performed by an electron diode and ion chamber for electron and photon beam dosimetry, respectively, indicating the minimal effect of Čerenkov contamination. Compared with a silver/dielectric coated HWG fiber dosimeter design we observed higher signal transmission in our design based on the use of silver-only HWG.

  11. High harmonic generation in a gas-filled hollow-core photonic crystal fiber

    Science.gov (United States)

    Heckl, O. H.; Baer, C. R. E.; Kränkel, C.; Marchese, S. V.; Schapper, F.; Holler, M.; Südmeyer, T.; Robinson, J. S.; Tisch, J. W. G.; Couny, F.; Light, P.; Benabid, F.; Keller, U.

    2009-10-01

    :270, 2007). The interaction between the laser pulses and the gas occurs in a Kagome-type Hollow-Core Photonic Crystal Fiber (HC-PCF) (Benabid et al., Science 298:399, 2002), which reduces the detection threshold for HHG to only 200 nJ. This novel type of fiber guides nearly all of the light in the hollow core (Couny et al., Science 318:1118, 2007), preventing damage even at intensities required for HHG. Our fiber guided 30-fs pulses with a pulse energy of more than 10 μJ, which is more than five times higher than for any other photonic crystal fiber (Hensley et al., Conference on Lasers and Electro-Optics (CLEO), IEEE Press, New York, 2008).

  12. Full-Scale Hollow Fiber Spacesuit Water Membrane Evaporator Prototype Development and Testing for Advanced Spacesuits

    Science.gov (United States)

    Bue, Grant; Trevino, Luis; Tsioulos, Gus; Mitchell, Keith; Dillon, Paul; Weaver, Gregg

    2009-01-01

    The spacesuit water membrane evaporator (SWME) is being developed to perform the thermal control function for advanced spacesuits to take advantage of recent advances in micropore membrane technology in providing a robust heat-rejection device that is potentially less sensitive to contamination than is the sublimator. Principles of a sheet membrane SWME design were demonstrated using a prototypic test article that was tested in a vacuum chamber at JSC in July 1999. The Membrana Celgard X50-215 microporous hollow fiber (HoFi) membrane was selected after recent contamination tests as the superior candidate among commercial alternatives for HoFi SWME prototype development. Although a number of design variants were considered, one that grouped the fiber layers into stacks, which were separated by small spaces and packaged into a cylindrical shape, was deemed best for further development. An analysis of test data showed that eight layer stacks of the HoFi sheets that had good exposure on each side of the stack would evaporate water with high efficiency. A design that has 15,000 tubes, with 18 cm of exposed tubes between headers has been built and tested that meets the size, weight, and performance requirements of the SWME. This full-scale prototype consists of 30 stacks, each of which are formed into a chevron shape and separated by spacers and organized into three sectors of ten nested stacks. Testing has been performed to show contamination resistance to the constituents expected to be found in potable water produced by the distillation processes. Other tests showed the sensitivity to surfactants.

  13. Mathematical and experimental analyses of antibody transport in hollow-fiber-based specific antibody filters.

    Science.gov (United States)

    Hout, Mariah S; Federspiel, William J

    2003-01-01

    We are developing hollow fiber-based specific antibody filters (SAFs) that selectively remove antibodies of a given specificity directly from whole blood, without separation of the plasma and cellular blood components and with minimal removal of plasma proteins other than the targeted pathogenic antibodies. A principal goal of our research is to identify the primary mechanisms that control antibody transport within the SAF and to use this information to guide the choice of design and operational parameters that maximize the SAF-based antibody removal rate. In this study, we formulated a simple mathematical model of SAF-based antibody removal and performed in vitro antibody removal experiments to test key predictions of the model. Our model revealed three antibody transport regimes, defined by the magnitude of the Damköhler number Da (characteristic antibody-binding rate/characteristic antibody diffusion rate): reaction-limited (Da /= 10). For a given SAF geometry, blood flow rate, and antibody diffusivity, the highest antibody removal rate was predicted for diffusion-limited antibody transport. Additionally, for diffusion-limited antibody transport the predicted antibody removal rate was independent of the antibody-binding rate and hence was the same for any antibody-antigen system and for any patient within one antibody-antigen system. Using SAF prototypes containing immobilized bovine serum albumin (BSA), we measured anti-BSA removal rates consistent with transport in the intermediate regime (Da approximately 3). We concluded that initial SAF development work should focus on achieving diffusion-limited antibody transport by maximizing the SAF antibody-binding capacity (hence maximizing the characteristic antibody-binding rate). If diffusion-limited antibody transport is achieved, the antibody removal rate may be raised further by increasing the number and length of the SAF fibers and by increasing the blood flow rate through the SAF.

  14. Enhanced forward osmosis from chemically modified polybenzimidazole (PBI) nanofiltration hollow fiber membranes with a thin wall

    KAUST Repository

    Wang, Kai Yu

    2009-04-01

    To develop high-flux and high-rejection forward osmosis (FO) membranes for water reuses and seawater desalination, we have fabricated polybenzimidazole (PBI) nanofiltration (NF) hollow fiber membranes with a thin wall and a desired pore size via non-solvent induced phase inversion and chemically cross-linking modification. The cross-linking by p-xylylene dichloride can finely tune the mean pore size and enhance the salt selectivity. High water permeation flux and improved salt selectivity for water reuses were achieved by using the 2-h modified PBI NF membrane which has a narrow pore size distribution. Cross-linking at a longer time produces even a lower salt permeation flux potentially suitable for desalination but at the expense of permeation flux due to tightened pore sizes. It is found that draw solution concentration and membrane orientations are main factors determining the water permeation flux. In addition, effects of membrane morphology and operation conditions on water and salt transport through membrane have been investigated. © 2008 Elsevier Ltd. All rights reserved.

  15. Perovskite Hollow Fibers with Precisely Controlled Cation Stoichiometry via One-Step Thermal Processing.

    Science.gov (United States)

    Zhu, Jiawei; Zhang, Guangru; Liu, Gongping; Liu, Zhengkun; Jin, Wanqin; Xu, Nanping

    2017-05-01

    The practical applications of perovskite hollow fibers (HFs) are limited by challenges in producing these easily, cheaply, and reliably. Here, a one-step thermal processing approach is reported for the efficient production of high performance perovskite HFs, with precise control over their cation stoichiometry. In contrast to traditional production methods, this approach directly uses earth-abundant raw chemicals in a single thermal process. This approach can control cation stoichiometry by avoiding interactions between the perovskites and polar solvents/nonsolvents, optimizes sintering, and results in high performance HFs. Furthermore, this method saves much time and energy (≈ 50%), therefore pollutant emissions are greatly reduced. One successful example is Ba0.5Sr0.5Co0.8Fe0.2O3-δ HFs, which are used in an oxygen-permeable membrane. This exhibits high oxygen permeation flux values that exceed desired commercial targets and compares favorably with previously reported oxygen-permeable membranes. Studies on other perovskites have produced similarly successful results. Overall, this approach could lead to energy efficient, solid-state devices for industrial application in energy and environmental fields. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Pulsed-induced electromagnetically induced transparency in the acetylene-filled hollow-core fibers

    Science.gov (United States)

    Rodríguez, Nayeli Casillas; Stepanov, Serguei; Miramontes, Manuel Ocegueda; Hernández, Eliseo Hernández

    2017-06-01

    Experimental results on pulsed excitation of electromagnetically induced transparency (EIT) in the acetylene-filled hollow-core photonic crystal fiber (HC-PCF) at pressures 0.1-0.4 Torr are reported. The EIT was observed both in Λ and V interaction configurations with the continuous probe wave tuned to R9 (1520.08 nm) acetylene absorption line and with the control pulses tuned to P11 (1531.58 nm) and P9 (1530.37 nm) lines, respectively. The utilized control pulses were of up to 40 ns duration with qualitative explanation of reduction in the counter-propagation EIT efficiency a simple model of the accelerated mismatch of the two-frequency EIT resonance with deviation of the molecule thermal velocity from the resonance value was utilized. It was shown experimentally that the EIT efficiencies in both configurations do not depend on the longitudinal velocity of the molecules. The characteristic relaxation time of the of the EIT response was found to be about 9 ns, i.e., is close to the relaxation times T 1,2 of the acetylene molecules under the utilized experimental conditions.

  17. Flexural Strength of Carbon Fiber Reinforced Polymer Repaired Cracked Rectangular Hollow Section Steel Beams

    Directory of Open Access Journals (Sweden)

    Tao Chen

    2015-01-01

    Full Text Available The flexural behavior of rectangular hollow section (RHS steel beams with initial crack strengthened externally with carbon fiber reinforced polymer (CFRP plates was studied. Eight specimens were tested under three-point loading to failure. The experimental program included three beams as control specimens and five beams strengthened with CFRP plates with or without prestressing. The load deflection curves were graphed and failure patterns were observed. The yield loads and ultimate loads with or without repairing were compared together with the strain distributions of the CFRP plate. It was concluded that yield loads of cracked beams could be enhanced with repairing. Meanwhile, the ultimate loads were increased to some extent. The effect of repair became significant with the increase of the initial crack depth. The failure patterns of the repaired specimens were similar to those of the control ones. Mechanical clamping at the CFRP plate ends was necessary to avoid premature peeling between the CFRP plate and the steel beam. The stress levels in CFRP plates were relatively low during the tests. The use of prestressing could improve the utilization efficiency of CFRP plates. It could be concluded that the patching repair could be used to restore the load bearing capacity of the deficient steel beams.

  18. Hydrodynamic Study of a Hollow Fiber Membrane System Using Experimental and Numerical Derived Surface Shear Stresses

    DEFF Research Database (Denmark)

    Ratkovich, Nicolas Rios; Hunze, M.; Nopens, I.

    2012-01-01

    : 0.25 – 0.49 Pa) with an error of less than 5 %; (ii) high shear stresses (i.e. 90th percentile) predictions were much less accurate (model: 0.60 – 1.23 Pa; experimental: 1.04 – 1.90 Pa) with an error up to 38 %. This was attributed to the fact that the CFD model only considers the two-phase flow (50......Computational Fluids Dynamics (CFD) models can be used to gain insight into the shear stresses induced by air sparging on submerged hollow fiber Membrane BioReactor (MBR) systems. It was found that the average range of shear stresses obtained by the CFD model (0.30 – 0.60 Pa) and experimentally (0.......39 – 0.69 Pa) were in good agreement, with an error less that 15 %. Based on comparison of the cumulative frequency distribution of shear stresses from experiments and simulation: (i) moderate shear stresses (i.e. 50th percentile) were found to be accurately predicted (model: 0.24 – 0.45 Pa; experimental...

  19. Fabrication of Functionalized MOFs Incorporated Mixed Matrix Hollow Fiber Membrane for Gas Separation

    Directory of Open Access Journals (Sweden)

    Haitao Zhu

    2017-01-01

    Full Text Available The metal-organic framework (MOFs of MIL-53 was functionalized by aminosilane grafting and then incorporated into Ultem®1000 polymer matrix to fabricate mixed matrix hollow fiber membrane (MMHFM with high separation performance. SEM, XRD, and TGA were performed to characterize the functionalized MIL-53 and prepared MMHFM. The filler particles were embedded in membrane successfully and dispersed well in the polymer matrix. The incorporation of MOFs endowed MMHFM better thermal stability. Moreover, effects of solvent ratio in spinning dope, spinning condition, and testing temperature on gas separation performance of MMHFM were investigated. By optimizing dope composition, air gap distance, and bore fluid composition, MMHFM containing functionalized MIL-53 achieved excellent gas permeance and CO2/N2 selectivity. The CO2 permeance increased from 12.2 GPU for pure Ultem HFM to 30.9 GPU and the ideal CO2/N2 selectivity was enhanced from 25.4 to 34.7 simultaneously. Additionally, gas permeance increased but the selectivity decreased with the temperature increase, which followed the solution-diffusion based transport mechanism.

  20. Understanding the risk of scaling and fouling in hollow fiber forward osmosis membrane application

    KAUST Repository

    Majeed, Tahir

    2016-06-23

    Fouling studies of forward osmosis (FO) were mostly conducted based on fouling evaluation principals applied to pressure membrane processes such as reverse osmosis (RO)/nanofiltration (NF)/microfiltration (MF)/ultrafiltration (UF). For RO/NF/MF/UF processes, the single flux driving force (hydraulic pressure) remains constant, thus the fouling effect is easily evaluated by comparing flux data with the baseline. Whilst, the scenario of fouling effects for FO process is entirely different from RO/NF/MF/UF processes. Continuously changing driving force (osmotic pressure difference), the changes in concentration polarization associated with the varying draw solution/feed solution concentration and the fouling layer effects collectively influence the FO flux. Thus, usual comparison of the FO flux outcome with the baseline results can not exactly indicate the real affect of membrane fouling, rather presents a misleading cumulative effect. This study compares the existing FO fouling technique with an alternate fouling evaluation approach using two FO set-ups. Scaling and fouling risk for hollow fiber FO was separately investigated using synthetic water samples and model organic foulants as alginate, humic acid and bovine serum albumin. Results indicated that FO flux declines up to 5% and 49% in active layer-feed solution and active layer-draw solution orientations respectively.

  1. Recovery Properties of Polysulfone Hollow Fiber Chelating Membrane Modified with Thiourea for Mercury ( Ⅱ )

    Institute of Scientific and Technical Information of China (English)

    WANG Bing; XIAO Feng; HUANG Lei

    2007-01-01

    The adsorption isotherms of the polysulfone hollow fiber chelating membrane modified with thiourea as chelating groups for Hg2+ were determined. The effects of mobile phase conditions and the operating parameters on removal performance of the chelating membrane for Hg2+ were also investigated. The recovery of Hg2+ decreased at low pH and the optimum range of pH was from 6 to 7. The feed concentration effected on recovery of Hg2+ at the specified loading amount of Hg2+. The Hg2+ could be removed from different concentration feed solution by chelating membrane. The increase of feed flow rate led to slight decrease of recovery of Hg2+ at the specified loading amount of Hg2+. The chelating membrane could be operated at height feed flow rate and a large-scale removal of Hg2+ could be realized. With the increase of load amount, Hg2+ recovery decreased, but the saturation degree of chelating membrane increased. According to required recovery of Hg2+ and the saturation degree of chelating membrane, the optimum loading amount of Hg2+ should be selected in the actual removal of Hg2+.

  2. Hollow-fiber membrane bioreactor for the treatment of high-strength landfill leachate

    KAUST Repository

    Rizkallah, Marwan

    2013-07-15

    Performance assessment of membrane bioreactor (MBR) technology for the treatability of high-strength landfill leachate is relatively limited or lacking. This study examines the feasibility of treating high-strength landfill leachate using a hollow-fiber MBR. For this purpose, a laboratory-scale MBR was constructed and operated to treat leachate with a chemical oxygen demand (COD) of 9000-11,000 mg/l, a 5-day biochemical oxygen demand (BOD5) of 4000-6,000 mg/l, volatile suspended solids (VSS) of 300-500 mg/l, total nitrogen (TN) of 2000-6000 mg/l, and an ammonia-nitrogen (NH3-N) of 1800-4000 mg/l. VSS was used with the BOD and COD data to simulate the biological activity in the activated sludge. Removal efficiencies > 95-99% for BOD5, VSS, TN and NH3-N were attained. The coupled experimental and simulation results contribute in filling a gap in managing high-strength landfill leachate and providing guidelines for corresponding MBR application. © The Author(s) 2013.

  3. Experimental investigation and modeling of industrial oily wastewater treatment using modified polyethersulfone ultrafiltration hollow fiber membranes

    Energy Technology Data Exchange (ETDEWEB)

    Salahi, Abdolhamid; Mohammadi, Toraj [Iran University of Science and Technology (IUST), Tehran (Iran, Islamic Republic of); Behbahani, Reza Mosayebi [Petroleum University of Technology (PUT), Ahwaz (Iran, Islamic Republic of); Hemmati, Mahmood [Research Institute of Petroleum Industry, Tehran (Iran, Islamic Republic of)

    2015-06-15

    Hollow fiber membranes were prepared from polyethersulfone/additives/NMP and DMSO system via phase inversion induced by precipitation in non-solvent coagulation bath. The interaction effects of polyethylene-glycol (PEG), propionic-acid (PA), Tween-20, PEG molecular weight and polyvinyl-pyrrolidone (PVP) on morphology and performance of synthesized membranes were investigated. Taguchi method (L{sub 16} orthogonal array) was used initially to plan a minimum number of experiments. 32 membranes were synthesized (with two replications) and their permeation flux and TOC rejection properties to oily wastewater treatment were studied. The obtained results indicated that addition of PA to spinning dope decreases flux while it increases TOC rejection of prepared membranes. Also, the result shows that addition of PVP, Tween-20 and PEG content in spinning dope enhances permeation flux while reducing TOC rejection. The obtained results indicated that the synthesized membranes was effective and suitable for treatment of the oily wastewater to achieve up to 92.6, 98.2, and 98.5% removal of TOC, TSS, and OGC, respectively with a flux of 247.19 L/(m{sup 2}h). Moreover, Hermia's models were used for permeation flux decline prediction. Experimental data and models predictions were compared. The results showed that there is reasonable agreement between experimental data and the cake layer model followed by the intermediate blocking model.

  4. Preparation and Preliminary Dialysis Performance Research of Polyvinylidene Fluoride Hollow Fiber Membranes

    Directory of Open Access Journals (Sweden)

    Qinglei Zhang

    2015-03-01

    Full Text Available In this study, the separation properties of Polyvinylidene fluoride (PVDF hollow fiber hemodialysis membranes were improved by optimizing membrane morphology and structure. The results showed that the PVDF membrane had better mechanical and separation properties than Fresenius Polysulfone High-Flux (F60S membrane. The PVDF membrane tensile stress at break, tensile elongation and bursting pressure were 11.3 MPa, 395% and 0.625 MPa, respectively. Ultrafiltration (UF flux of pure water reached 108.2 L∙h−1∙m−2 and rejection of Albumin from bovine serum was 82.3%. The PVDF dialyzers were prepared by centrifugal casting. The influences of membrane area and simulate fluid flow rate on dialysis performance were investigated. The results showed that the clearance rate of urea and Lysozyme (LZM were improved with increasing membrane area and fluid flow rate while the rejection of albumin from bovine serum (BSA had little influence. The high-flux PVDF dialyzer UF coefficient reached 62.6 mL/h/mmHg. The PVDF dialyzer with membrane area 0.69 m2 has the highest clearance rate to LZM and urea. The clearance rate of LZM was 66.8% and urea was 87.7%.

  5. Hemocompatibility evaluation of small elastomeric hollow fiber membranes as vascular substitutes.

    Science.gov (United States)

    Mercado-Pagán, Ángel E; Ker, Dai Fei Elmer; Yang, Yunzhi

    2014-10-01

    One of the main challenges for clinical implementation of small diameter vascular grafts (SDVGs) is their limited hemocompatibility. Important design specifications for such grafts include features that minimize the long-term risks of restenosis, fouling, and thrombus formation. In our lab, we have developed elastomeric hollow fiber membranes (HFMs), using a phase inversion method, as candidates for SDVGs. Here, we present our results for in vitro hemocompatibility testing of our HFM under flow and static conditions. Our results showed that the polymer-based HFMs do not damage the integrity of human red blood cells (RBCs) as shown by their low hemolytic extent (less than 2%). When analyzed for blood cell lysis using lactate dehydrogenase (LDH) activity as an indicator, no significant differences were observed between blood exposed to our HFMs and uncoagulated blood. Analysis of protein adsorption showed a low concentration of proteins deposited on the surfaces of HFM after 24 h. Platelet adhesion profiles using human platelet-rich plasma (PRP) showed that a low level of platelets adhered to the HFMs after 24 h, indicating minimal thrombotic potential. Under the majority of conditions, no significant differences were observed between medical-grade polymers and our HFMs. Eventual optimization of hemocompatible elastomeric HFM vessel grafts could lead to improved tissue vascularization as well as vascularized, tissue-engineered scaffolds for organ repair.

  6. Development and characterization of microfiltration hollow-fiber modules for sterilization of fermentation media

    Directory of Open Access Journals (Sweden)

    L.F.F. Faria

    2002-04-01

    Full Text Available Sterilization of fermentation medium involving heat may result in undesirable chemical reactions that alter nutrient concentration and yield products, which interfere in the fermentation performance. Sterilization of heat-sensitive compounds usually involves separate sterilizations of carbon source and nutrient solution. Membrane separation processes are an alternative to thermal processes, as they have many advantages such as the possibility of continuous and modular operation and the use of moderate temperatures. In this context, the objective of this work was the preparation of hollow-fiber membranes and the design of modules suitable for continuous sterilization of fermentation medium. The membrane with the best performance had a maximum pore diameter of 0.2 mu m and a permeability of 42.9 L/m².bar.h for a glucose/peptone/yeast extract medium. A module with 0.26 m² of permeation area was built with these membranes. This module was able to provide a permeate flow rate of 2.2 L/h using a pressure difference of 0.2 bar. The collected permeate was completely sterile, thus confirming the efficiency of this process.

  7. Surface monofunctionalized polymethyl pentene hollow fiber membranes by plasma treatment and hemocompatibility modification for membrane oxygenators

    Science.gov (United States)

    Huang, Xin; Wang, Weiping; Zheng, Zhi; Fan, Wenling; Mao, Chun; Shi, Jialiang; Li, Lei

    2016-01-01

    The hemocompatibility of polymethyl pentene (PMP) hollow fiber membranes (HFMs) was improved through surface modification for membrane oxygenator applications. The modification was performed stepwise with the following: (1) oxygen plasma treatment, (2) functionalization of monosort hydroxyl groups through NaBH4 reduction, and (3) grafting 2-methacryloyloxyethyl phosphorylcholine (MPC) or heparin. SEM, ATR-FTIR, and XPS analyses were conducted to confirm successful grafting during the modification. The hemocompatibility of PMP HFMs was analyzed and compared through protein adsorption, platelet adhesion, and coagulation tests. Pure CO2 and O2 permeation rates, as well as in vitro gas exchange rates, were determined to evaluate the mass transfer properties of PMP HFMs. SEM results showed that different nanofibril topographies were introduced on the HFM surface. ATR-FTIR and XPS spectra indicated the presence of functionalization of monosort hydroxyl group and the grafting of MPC and heparin. Hemocompatibility evaluation results showed that the modified PMP HFMs presented optimal hemocompatibility compared with pristine HFMs. Gas permeation results revealed that gas permeation flux increased in the modified HFMs because of dense surface etching during the plasma treatment. The results of in vitro gas exchange rates showed that all modified PMP HFMs presented decreased gas exchange rates because of potential surface fluid wetting. The proposed strategy exhibits a potential for fabricating membrane oxygenators for biomedical applications to prevent coagulation formation and alter plasma-induced surface topology and composition.

  8. Covalent Immobilization of Lipase on Poly ( acrylonitrile-co-maleic acid) Ultrafiltration Hollow Fiber Membrane

    Institute of Scientific and Technical Information of China (English)

    YE Peng; XU Zhi-kang; WU Jian; DENG Hong-tao; SETA Patrick

    2005-01-01

    Lipase from Candida rugosa was covalently immobilized on the surface of an ultrafiltration hollow fiber membrane fabricated from poly (acrylonitrile-co-maleic acid) (PANCMA) in which the carboxyl groups were activated with 1-ethyl-3-(dimethylaminopropyl) carbodiimide hydrochloride (EDC) and dicyclohexyl carbodiimide (DCC)/N-hydroxyl succinimide(NHS), respectively. The properties of the immobilized lipase were assayed and compared with those of the free enzyme. The maximum activities were observed in a relatively broader pH value range at high temperatures for the immobilized lipase compared to the free one. It was also found that the thermal and pH stabilities of lipase were improved upon immobilization and at 50 ℃ the thermal inactivation rate constant values are 2.1×10-2 for the free lipase, 3.2×10-3 for the immobilized lipase on the EDC-activated PANCMA membrane and 3.5×10-3 for the immobilized lipase on the DCC/NHS-activated PANCMA membrane, respectively.

  9. Multi-objective Optimization of Solar-driven Hollow-fiber Membrane Distillation Systems.

    Energy Technology Data Exchange (ETDEWEB)

    Nenoff, Tina M.; Moore, S.; Mirchandani, S.; Karanikola, V.; Arnold, R.; Saez, E.

    2017-09-01

    Securing additional water sources remains a primary concern for arid regions in both the developed and developing world. Climate change is causing fluctuations in the frequency and duration of precipitation, which can be can be seen as prolonged droughts in some arid areas. Droughts decrease the reliability of surface water supplies, which forces communities to find alternate primary water sources. In many cases, ground water can supplement the use of surface supplies during periods of drought, reducing the need for above-ground storage without sacrificing reliability objectives. Unfortunately, accessible ground waters are often brackish, requiring desalination prior to use, and underdeveloped infrastructure and inconsistent electrical grid access can create obstacles to groundwater desalination in developing regions. The objectives of the proposed project are to (i) mathematically simulate the operation of hollow fiber membrane distillation systems and (ii) optimize system design for off-grid treatment of brackish water. It is anticipated that methods developed here can be used to supply potable water at many off-grid locations in semi-arid regions including parts of the Navajo Reservation. This research is a collaborative project between Sandia and the University of Arizona.

  10. Performance of Hollow Fiber Ultrafiltration Membranes in the Clarification of Blood Orange Juice

    Directory of Open Access Journals (Sweden)

    Carmela Conidi

    2015-12-01

    Full Text Available The clarification of blood orange juice by ultrafiltration (UF was investigated by using three hollow fiber membrane modules characterized by different membrane materials (polysulfone (PS and polyacrylonitrile (PAN and molecular weight cut-off (MWCO (50 and 100 kDa. The performance of selected membranes was investigated in terms of productivity and selectivity towards total anthocyanin content (TAC, total phenolic content (TPC, and total antioxidant activity (TAA. All selected membranes allowed a good preservation of antioxidant compounds; however, the most suitable membrane for the clarification of the juice was found to be the PS 100 kDa membrane. In optimized operating conditions this membrane exhibited steady-state fluxes of 7.12 L/m2h, higher than those measured for other investigated membranes. Rejections towards TPC and TAA were of the order of 17.5% and 15%, respectively. These values were lower than those determined for PS 50 kDa and PAN 50 kDa membranes. In addition, the PS 100 kDa membrane exhibited a lower rejection (7.3% towards TAC when compared to the PS 50 kDa membrane (9.2%.

  11. Sound Absorption Properties Of Single-Hole Hollow Polyester Fiber Reinforced Hydrogenated Carboxyl Nitrile Rubber Composites

    Directory of Open Access Journals (Sweden)

    Jie Hong

    2017-09-01

    Full Text Available A series of single-hole hollow polyester fiber (SHHPF reinforced hydrogenated carboxyl nitrile rubber (HXNBR composites were fabricated. In this study, the sound absorption property of the HXNBR/SHHPF composite was tested in an impedance tube, the composite morphology was characterized by scanning electron microscope (SEM, and the tensile mechanical property was measured by strength tester. The results demonstrated that a remarkable change in sound absorption can be observed by increasing the SHHPF content from 0% to 40%. In the composite with 40% SHHPF in 1 mm thickness, the sound absorption coefficient reached 0.671 at 2,500 Hz; the effective bandwidth was 1,800-2,500 Hz for sound absorption coefficient larger than 0.2. But the sound absorption property of the composite deteriorated when the SHHPF content increased to 50% in 1 mm thickness. While with 20% SHHPF proportion, the sound absorption property was improved by increasing the thickness of composites from 1 to 5 mm. Compared with the pure HXNBR of the same thickness, the tensile mechanical property of the composite improved significantly by increasing the SHHPF proportion. As a lightweight composite with excellent sound absorption property, the HXNBR/SHHPF composite has potential practical application value in the fields of engineering.

  12. Continuous rhamnolipid production using denitrifying Pseudomonas aeruginosa cells in hollow-fiber bioreactor.

    Science.gov (United States)

    Pinzon, Neissa M; Cook, Aaron G; Ju, Lu-Kwang

    2013-01-01

    Rhamnolipids are high-value effective biosurfactants produced by Pseudomonas aeruginosa. Large-scale production of rhamnolipids is still challenging especially under free-cell aerobic conditions in which the highly foaming nature of the culture broth reduces the productivity of the process. Immobilized systems relying on oxygen as electron acceptor have been previously investigated but oxygen transfer limitation presents difficulties for continuous rhamnolipid production. A coupled system using immobilized cells and nitrate instead of oxygen as electron acceptor taking advantage of the ability of P. aeruginosa to perform nitrate respiration was evaluated. This denitrification-based immobilized approach based on a hollow-fiber setup eliminated the transfer limitation problems and was found suitable for continuous rhamnolipid production in a period longer than 1,500 h. It completely eliminated the foaming difficulties related to aerobic systems with a comparable specific productivity of 0.017 g/(g dry cells)-h and allowed easy recovery of rhamnolipids from the cell-free medium.

  13. Low loss broadband transmission in hypocycloid-core Kagome hollow-core photonic crystal fiber.

    Science.gov (United States)

    Wang, Y Y; Wheeler, N V; Couny, F; Roberts, P J; Benabid, F

    2011-03-01

    We report on the fabrication of a seven-cell-core and three-ring-cladding large-pitch Kagome-lattice hollow-core photonic crystal fiber (HC-PCF) with a hypocycloid-shaped core structure. We demonstrate experimentally and theoretically that the design of this core shape enhances the coupling inhibition between the core and cladding modes and offers optical attenuation with a baseline of ∼180 dB/km over a transmission bandwidth larger than 200 THz. This loss figure rivals the state-of-the-art photonic bandgap HC-PCF while offering an approximately three times larger bandwidth and larger mode areas. Also, it beats the conventional circular-core-shaped Kagome HC-PCF in terms of the loss. The development of this novel (to our knowledge) HC-PCF has potential for a number of applications in which the combination of a large optical bandwidth and a low loss is a prerequisite.

  14. Dispersion-free solvent extraction of Cr(VI) from acidic solutions using hollow fiber contactor.

    Science.gov (United States)

    Alguacil, Francisco J; Alonso, Manuel; Lopez, Félix A; Lopez-Delgado, Aurora; Padilla, Isabel

    2009-10-15

    The use of dispersión-free solvent extraction, through microporous hydrophobic membrane has been investigated. The hollow fiber contactor, with surface area of 1.4 m2 was used to extract Cr(VI) (0.005-0.12 g/L from aqueous sulphuric acidic media (pH 2.5-4.2 +/- 0.05). Several parameters such as extractant concentration, feed acidity and metal concentration in the initial aqueous solution were investigated. Results revealed that 15% v/v Cyanex 923 in Exxsol D-100 as organic phase and feed in the 2.5 pH range, gave optimum extraction (exceeding 95%) of Cr(VI) and it was possible to strip using 10 g/L hydrazine sulfate (also with recoveries exceeding 95%). In this step, Cr(VI) is immediately reduced to the less hazardous Cr(III) state. Results also showed that under the various experimental conditions, chromium(VI) extraction was rate-controlled by the interfacial reaction on the membrane surface. Typical overall mass transfer coefficients values are 4.2 x 10(-5) and 3.6 x 10(-6) cm/s for extraction and stripping operations, respectively.

  15. Broadband UV-Vis vibrational coherence spectrometer based on a hollow fiber compressor

    Science.gov (United States)

    Gueye, Moussa; Nillon, Julien; Crégut, Olivier; Léonard, Jérémie

    2016-09-01

    We describe a broadband transient absorption (TA) spectrometer devised to excite and probe, in the blue to UV range, vibrational coherence dynamics in organic molecules in condensed phase. A 800-nm Ti:Sa amplifier and a hollow fiber compressor are used to generate a 6-fs short pulse at 1 kHz. Broadband sum frequency generation with the fundamental pulse is implemented to produce a 400-nm, 8-fs Fourier limited short pulse. A UV-Vis white-light supercontinuum is implemented as a probe with intensity self-referencing to achieve a shot-noise-limited sensitivity. Rapid scanning of the pump-probe delay is shown very efficient in suppressing the noise resulting from low-frequency pump intensity fluctuations. Using either of the 800-nm or 400-nm broadband pulses as the pump for TA spectroscopy of organic molecules in solution, we resolve oscillatory signals down to the 320 nm probing wavelength with a 3200 cm-1 FWHM bandwidth. Their Fourier transformation reveals the corresponding molecular vibrational spectra. Finally, we demonstrate the use of this setup as a vibrational coherence spectrometer for the investigation of the vibrational dynamics accompanying the sub-ps C=C photoisomerization of a retinal-like molecular switch through a conical intersection.

  16. Operation Characteristics of Treating Surface Water with Polyvinylchloride Hollow Fiber Ultrafiltration Membrane

    Institute of Scientific and Technical Information of China (English)

    GUO Xiaoyan; ZHANG Zhenjia; FANG Lin; SU Liguo

    2006-01-01

    A pilot plant study on a polyvinylchloride hollow fiber ultrafiltration membrane process was conducted for treating surface water.The membrane system was operated in the dead-end filtration mode under different constant permeate fluxes.The results show that the optimized operation ( transmembrane pressure≤0.1 Mpa,filtration time≤30 min) with a hydraulic cleaning (30 s) and a chemical cleaning (30 min,the chemical cleaning was performed after 16 cycles of filtration ) en ures a quite steady flux (1 100 L/(m2·h · Mpa)) and good permeate quality (turbidity <0.1NTU ).A full-scale plant can be suggested to operate with a mixed strategy of constant permeate flux mode (transmembrane pressure ≤0.1 Mpa) and constant transmembrane pressure mode.When the temperature of raw water becomes below 5 ℃,a constant transmembrane pressure mode should be used; otherwise a constant permeate flux mode (transmembrane pressure ≤ 0.1 Mpa) can be operated.In this way,irreversible fouling of ultrafiltration membrane can be minimized to keep a stable flux and make the life of membrane longer.

  17. Non Dispersive Chemical Deacidification of Crude Palm Oil in Hollow Fiber Membrane Contactor

    Directory of Open Access Journals (Sweden)

    Mubiar Purwasasmita

    2015-09-01

    Full Text Available Performance of chemical deacidification of crude palm oil (CPO using aqueous NaOH solution in a polysulfone hollow fiber ultrafiltration membrane was investigated. The effects of operating temperature, NaOH concentration and flow rates on percentage of free fatty acids (FFA removal, oil loss, soap entrainment and overall mass transfer coefficient were evaluated. Overall mass transfer coefficients, soap content in oil and neutral oil loss all increased when the temperature was increased from 60 to 70°C due to an increase of the FFA distribution value. A minimum 0.25 N of NaOH or a NaOH to FFA molar ratio of about 7.62 was required to facilitate the expected extraction efficiency. The increased oil flowrate slightly enhanced the solute transport kinetics, while the aqueous phase flowrate did not significantly influence deacidification efficiency or mass transfer coefficient. About 97% of FFA removal was achieved within 4 hours. The maximum oil loss observed was 11% and the highest soap content in the oil without separation step was 3150 ppm. The values of the overall mass transfer coefficient varied from 2.97×10-7 to 7.71×10-7 m/s. These results show the potential of using the non dispersive membrane contacting process for chemical deacidification of CPO as well as other vegetable oils.

  18. Surface modification of PVDF hollow fiber membrane and its application in membrane aerated biofilm reactor (MABR).

    Science.gov (United States)

    Hou, Feifei; Li, Baoan; Xing, Minghao; Wang, Qin; Hu, Liang; Wang, Shichang

    2013-07-01

    A novel composite hollow fiber membrane for membrane aerated biofilm rector (MABR) was prepared by coating L-3,4-dihydroxyphenylalanine (DOPA) on the surface of PVDF membrane. MABR process study was conducted to test the performances of the original and modified membranes for 166 days. The results indicate that coated membrane showed 2 times higher gas flux, lower water contact angle (declined from 86.5° to 52°), and significantly improved surface roughness. The modified membrane displayed an excellent MABR performance. Its COD, NH4(+)-N and TN removal efficiencies were kept above 90%, 98.8% and 84.2% during the first 4-month experiment. By tracking experiment at 0.01 MPa, to achieve COD removal efficiency of 85.9%, half an hour is required with the modified membrane, instead of 6h using the original one. Besides, faster NH4(+)-N and TN removal at 0.01 MPa were also achieved with DOPA composite membrane. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Hydrodynamic Study of a Hollow Fiber Membrane System Using Experimental and Numerical Derived Surface Shear Stresses

    DEFF Research Database (Denmark)

    Ratkovich, Nicolas Rios; Hunze, M.; Nopens, I.

    2012-01-01

    Computational Fluids Dynamics (CFD) models can be used to gain insight into the shear stresses induced by air sparging on submerged hollow fiber Membrane BioReactor (MBR) systems. It was found that the average range of shear stresses obtained by the CFD model (0.30 – 0.60 Pa) and experimentally (0.......39 – 0.69 Pa) were in good agreement, with an error less that 15 %. Based on comparison of the cumulative frequency distribution of shear stresses from experiments and simulation: (i) moderate shear stresses (i.e. 50th percentile) were found to be accurately predicted (model: 0.24 – 0.45 Pa; experimental......: 0.25 – 0.49 Pa) with an error of less than 5 %; (ii) high shear stresses (i.e. 90th percentile) predictions were much less accurate (model: 0.60 – 1.23 Pa; experimental: 1.04 – 1.90 Pa) with an error up to 38 %. This was attributed to the fact that the CFD model only considers the two-phase flow (50...

  20. Functional Properties of Punica granatum L. Juice Clarified by Hollow Fiber Membranes

    Directory of Open Access Journals (Sweden)

    Francesco Galiano

    2016-07-01

    Full Text Available There is currently much interest in pomegranate juice because of the high content of phenolic compounds. Moreover, the interest in the separation of bioactive compounds from natural sources has remarkably grown. In this work, for the first time, the Punica granatum L. (pomegranate juice—clarified by using polyvinylidene fluoride (PVDF and polysulfone (PSU hollow fiber (HF membranes prepared in the laboratory—was screened for its antioxidant properties by using different in vitro assays, namely 2,2-diphenyl-1-picrylhydrazyl (DPPH, 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid (ABTS, Ferric Reducing Antioxidant Power (FRAP, and β-carotene bleaching tests, and for its potential inhibitory activity of the carbohydrate-hydrolysing enzymes, α-amylase and α-glucosidase. The effects of clarification on quality characteristics of the juice were also investigated in terms of total phenols, flavonoids, anthocyanins, and ascorbic acid. Experimental results indicated that PVDF membranes presented a lower retention towards healthy phytochemicals in comparison to PSU membranes. Accordingly, the juice clarified with PVDF membranes showed the best antioxidant activity. Moreover, the treatment with PVDF membranes produced a clarified juice with 2.9-times fold higher α-amylase inhibitory activity in comparison to PSU (IC50 value of 75.86 vs. 221.31 μg/mL, respectively. The same trend was observed using an α-glucosidase inhibition test. These results highlight the great potential of the clarified juice as a source of functional constituents.

  1. Detection of amino acid neurotransmitters by surface enhanced Raman scattering and hollow core photonic crystal fiber

    Science.gov (United States)

    Tiwari, Vidhu S.; Khetani, Altaf; Monfared, Ali Momenpour T.; Smith, Brett; Anis, Hanan; Trudeau, Vance L.

    2012-03-01

    The present work explores the feasibility of using surface enhanced Raman scattering (SERS) for detecting the neurotransmitters such as glutamate (GLU) and gamma-amino butyric acid (GABA). These amino acid neurotransmitters that respectively mediate fast excitatory and inhibitory neurotransmission in the brain, are important for neuroendocrine control, and upsets in their synthesis are also linked to epilepsy. Our SERS-based detection scheme enabled the detection of low amounts of GLU (10-7 M) and GABA (10-4 M). It may complement existing techniques for characterizing such kinds of neurotransmitters that include high-performance liquid chromatography (HPLC) or mass spectrography (MS). This is mainly because SERS has other advantages such as ease of sample preparation, molecular specificity and sensitivity, thus making it potentially applicable to characterization of experimental brain extracts or clinical diagnostic samples of cerebrospinal fluid and saliva. Using hollow core photonic crystal fiber (HC-PCF) further enhanced the Raman signal relative to that in a standard cuvette providing sensitive detection of GLU and GABA in micro-litre volume of aqueous solutions.

  2. Preparation, ferromagnetic and photocatalytic performance of NiO and hollow Co{sub 3}O{sub 4} fibers through centrifugal-spinning technique

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Cong; Lin, Xuejun; Wang, Xinqiang, E-mail: xqwang@sdu.edu.cn; Liu, Hongjing; Liu, Benxue; Zhu, Luyi; Zhang, Guanghui; Xu, Dong

    2016-02-15

    Highlights: • NiO and hollow Co{sub 3}O{sub 4} fibers with the diameter of about 10 μm were prepared through centrifugal-spinning technique. • The evolution mechanism from precursor to crystalline fibers was explored. • Both NiO and hollow Co{sub 3}O{sub 4} fibers show ferromagnetism. • The NiO fibers exhibit good photocatalytic performance. - Abstract: Both NiO and hollow Co{sub 3}O{sub 4} fibers with the diameter of about 10 μm have been successfully prepared through spinning high viscous sols into precursor fibers and followed calcination process. The evolution process from precursor to crystalline fibers and the microstructures of the obtained fibers were characterized by TG-DSC, FT-IR, XRD, HRTEM, SEM and the like. The method is facile and cost-effective for mass production of fibers and the obtained fibers are pure phase with high crystallinity. Their magnetic properties were investigated, showing that both the fibers are ferromagnetic. Meanwhile, the NiO fibers exhibit good photocatalytic performance for the removal of Congo red from water under UV light irradiation.

  3. Solvent exchange using hollow fiber prior to separation and determination of some antioxidants by high performance liquid chromatography.

    Science.gov (United States)

    Farajzadeh, Mir Ali; Jönsson, Jan Ake

    2007-06-26

    This study presents a simple and rapid solvent exchange procedure using a hollow fiber. Antioxidants (Irganox 1010, Irganox 1076 and Irgafos 168) and solvents such as tetrahydrofuran (THF), carbon tetrachloride and toluene were selected as model compounds and sample solvents, respectively. After injection of the sample solution into the hollow fiber and solvent evaporation, the precipitated analytes in lumen and pores of the fiber were washed with methanol (the mobile phase for separation and determination by HPLC-diode array detection) and good chromatographic peaks were obtained. The effect of different parameters such as fiber length, volumes of sample and washing solvents were investigated and the optimum conditions were selected. The repeatability of the method was tested and it was found that the relative standard deviation (R.S.D.) was less than 10% for all analytes. Also enrichment factors of 3.03, 2.21 and 1.19 times were obtained for Irganox 1010, Irganox 1076 and Irgafos 168, respectively, when 200 microL sample and 50 microL methanol (washing solvent) were used.

  4. Monolithic all-PM femtosecond Yb-fiber laser stabilized with a narrow-band fiber Bragg grating and pulse-compressed in a hollow-core photonic crystal fiber

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry; Liu, Xiaomin; Lægsgaard, Jesper

    2008-01-01

    We report on an environmentally stable self-starting monolithic (i.e. without any free-space coupling) all-polarization-maintaining (PM) femtosecond Yb-fiber laser, stabilized against Q-switching by a narrow-band fiber Bragg grating and modelocked using a semiconductor saturable absorber mirror....... The laser output is compressed in a spliced-on hollow-core PM photonic crystal fiber, thus providing direct end-of-the-fiber delivery of pulses of around 370 fs duration and 4 nJ energy with high mode quality. Tuning the pump power of the end amplifier of the laser allows for the control of output pulse...

  5. Optimization of the contents of hollow glass microsphere and sodium hexametaphosphate for glass fiber vacuum insulation panel

    Science.gov (United States)

    Li, C. D.; Chen, Z. F.; Zhou, J. M.

    2016-07-01

    In this paper, various additive amounts of hollow glass microspheres (HGMs) and sodium hexametaphosphate (SHMP) powders were blended with flame attenuated glass wool (FAGW) to form hybrid core materials (HCMs) through the wet method. Among them, the SHMP was dissolved in the glass fiber suspension and coated on the surface of glass fibers while the HGMs were insoluble in the glass fiber suspension and filled in the fiber-fiber pores. The average pore diameter of the FAGW/HGM HCMs was 8-11 μm which was near the same as that of flame attenuated glass fiber mats (FAGMs, i.e., 10.5 µm). The tensile strength of the SHMP coated FAGMs was enhanced from 160 N/m to 370 N/m when SHMP content increased from 0 wt.% to 0.2 wt.%. By contrast, the tensile strength of the FAGW/HGM HCMs decreased from 160 N/m to 40 N/m when HGM content increased from 0 wt.% to 50 wt.%. Both the FAGW/HGM HCMs and SHMP coated FAGMs were vacuumed completely to form vacuum insulation panels (VIPs). The results showed that both the addition of SHMP and HGM led a slight increase in the thermal conductivity of the corresponding VIPs. To obtain a high-quality VIP, the optimal SHMP content and HGM content in glass fiber suspension was 0.12-0.2 wt.% and 0 wt.%.

  6. Theory of photoionization-induced blueshift of ultrashort solitons in gas-filled hollow-core photonic crystal fibers.

    Science.gov (United States)

    Saleh, Mohammed F; Chang, Wonkeun; Hölzer, Philipp; Nazarkin, Alexander; Travers, John C; Joly, Nicolas Y; Russell, Philip St J; Biancalana, Fabio

    2011-11-11

    We show theoretically that the photoionization process in a hollow-core photonic crystal fiber filled with a Raman-inactive noble gas leads to a constant acceleration of solitons in the time domain with a continuous shift to higher frequencies, limited only by ionization loss. This phenomenon is opposite to the well-known Raman self-frequency redshift of solitons in solid-core glass fibers. We also predict the existence of unconventional long-range nonlocal soliton interactions leading to spectral and temporal soliton clustering. Furthermore, if the core is filled with a Raman-active molecular gas, spectral transformations between redshifted, blueshifted, and stabilized solitons can take place in the same fiber.

  7. Theory of Photoionization-Induced Blueshift of Ultrashort Solitons in Gas-Filled Hollow-Core Photonic Crystal Fibers

    Science.gov (United States)

    Saleh, Mohammed F.; Chang, Wonkeun; Hölzer, Philipp; Nazarkin, Alexander; Travers, John C.; Joly, Nicolas Y.; Russell, Philip St. J.; Biancalana, Fabio

    2011-11-01

    We show theoretically that the photoionization process in a hollow-core photonic crystal fiber filled with a Raman-inactive noble gas leads to a constant acceleration of solitons in the time domain with a continuous shift to higher frequencies, limited only by ionization loss. This phenomenon is opposite to the well-known Raman self-frequency redshift of solitons in solid-core glass fibers. We also predict the existence of unconventional long-range nonlocal soliton interactions leading to spectral and temporal soliton clustering. Furthermore, if the core is filled with a Raman-active molecular gas, spectral transformations between redshifted, blueshifted, and stabilized solitons can take place in the same fiber.

  8. Aluminum-coated hollow glass fibers for ArF-excimer laser light fabricated by metallorganic chemical-vapor deposition.

    Science.gov (United States)

    Matsuura, Y; Miyagi, M

    1999-04-20

    A hollow fiber composed of a glass capillary tube and a metal thin film upon the inside of the tube is proposed for the delivery of ArF-excimer laser light. From theoretical analysis, aluminum is chosen as the metal layer. A thin aluminum film is deposited by metallorganic chemical-vapor deposition, with dimethylethylamine alane employed as the source material. Measured loss spectra in vacuum-ultraviolet and ultraviolet regions and losses for ArF-excimer laser light show the low-loss property of the aluminum-coated fiber at the 193-nm wavelength of ArF-excimer laser light. The straight loss of the 1-m long, 1-mm-bore fiber is 1.0 dB.

  9. Soliton self-frequency blue-shift in gas-filled hollow-core photonic crystal fibers

    CERN Document Server

    Saleh, Mohammed F; Hoelzer, Philipp; Nazarkin, Alexander; Travers, John C; Joly, Nicolas Y; Russell, Philip St J; Biancalana, Fabio

    2011-01-01

    We show theoretically that the photoionization process in a hollow-core photonic crystal fiber filled with a Raman-inactive noble gas leads to a constant acceleration of solitons in the time domain with a continuous shift to higher frequencies, limited only by ionization loss. This phenomenon is opposite to the well-known Raman self-frequency red-shift of solitons in solid-core glass fibers. We also predict the existence of unconventional long-range non-local soliton interactions leading to spectral and temporal soliton clustering. Furthermore, if the core is filled with a Raman-active molecular gas, spectral transformations between red-shifted, blue-shifted and stabilized solitons can take place in the same fiber.

  10. GeO2-SiO2-chitosan-medium-coated hollow optical fiber for cell immobilization.

    Science.gov (United States)

    Zhong, Nian-Bing; Zhu, Xun; Liao, Qiang; Wang, Yong-Zhong; Chen, Rong

    2013-08-15

    A GeO(2)-SiO(2)-chitosan-medium (GSCM)-coated hollow optical fiber (HOF) is proposed. The HOF consists of three parts: the fiber core (air), cladding (SiO(2)), and coating (GSCM), which shows the highest refractive index of the three. The HOF's luminescence properties and surface morphology are investigated. Their adsorption capacity for Rhodopseudomonas palustris CQK 01 is also assayed. We discovered that when the amount of 2GeO(2)-SiO(2) sol dopant is 0.9 mass percent, the HOF exhibits the highest luminous intensity and uniform light distribution, and the adsorption capacity for the cell is 3.2 times higher than that of a normal solid optical fiber.

  11. Hydrogen Permeation Performance of Ni-BaZr0.1Ce0.7Y0.2O3-δ Metal-Ceramic Hollow Fiber Membrane

    Institute of Scientific and Technical Information of China (English)

    Chun-li Yang; Qi-ming Xu; Zhi-wen Zhu; Wei Liu

    2012-01-01

    A dense Ni-BaZr0.1Ce0.7Y0.2O3-δ (BZCY) cermet hollow fiber is fabricated by sintering NiOBZCY hollow fiber precursors prepared by phase inversion method in 5%H2/95%Ar and its hydrogen permeation performance is investigated. The Ni-BZCY hollow fiber membrane possesses a "sandwich" structure.Finger-like structures are observed near both the inner and outer surfaces,while a dense layer is present in the center part.With 200 mL/min wet 20%H2/80%N2 on the shell side and 150 mL/min high purity Ar on the core side,the hydrogen permeation flux through the Ni-BZCY hollow fiber membrane at 900 ℃ is 0.53 μmol/cm2s.Owing to a high packing density,the hydrogen permeation flux per unit volume is greatly improved and membrane components composed of an assembly of hollow fibers may be applied in industrial hydrogen separation.

  12. High-Energy, Multicolor Femtosecond Pulses from the Deep Ultraviolet to the Near Infrared Generated in a Hydrogen-Filled Gas Cell and Hollow Fiber

    Directory of Open Access Journals (Sweden)

    Kazuya Motoyoshi

    2014-07-01

    Full Text Available We investigate four-wave mixing in hydrogen gas using a gas cell and a hollow fiber for the generation of high-energy, multicolor femtosecond (fs optical pulses. Both a hydrogen-filled gas cell and hollow fiber lead to the generation of multicolor fs pulses in a broad spectral range from the deep ultraviolet to the near infrared. However, there is a difference in the energy distribution of the multicolor emission between the gas cell and the hollow fiber. The hydrogen-filled gas cell generates visible pulses with higher energies than the pulses created by the hollow fiber. We have generated visible pulses with energies of several tens of microjoules. The hydrogen-filled hollow fiber, on the other hand, generates ultraviolet pulses with energies of a few microjoules, which are higher than the energies of the ultraviolet pulses generated in the gas cell. In both schemes, the spectral width of each emission line supports a transform-limited pulse duration shorter than 15 fs. Four-wave mixing in hydrogen gas therefore can be used for the development of a light source that emits sub-20 fs multicolor pulses in a wavelength region from the deep ultraviolet to the near infrared with microjoule pulse energies.

  13. Diffusive and convective transport through hollow fiber membranes for liver cell culture.

    Science.gov (United States)

    Curcio, E; De Bartolo, L; Barbieri, G; Rende, M; Giorno, L; Morelli, S; Drioli, E

    2005-05-25

    For an efficient membrane bioreactor design, transport phenomena determining the overall mass flux of metabolites, catabolites, cell regulatory factors, and immune-related soluble factors, need to be clarified both experimentally and theoretically. In this work, experiments and calculations aimed at discerning the simultaneous influence of both diffusive and convective mechanisms to the transport of metabolites. In particular, the transmembrane mass flux of glucose, bovine serum albumin (BSA), APO-transferrin, immunoglobulin G, and ammonia was experimentally measured, under pressure and concentration gradients, through high-flux microporous hydrophilic poly-ether-sulphone (PES-HFMs) and poly-sulphone hollow fiber membranes (PS-HFMs). These data were analyzed by means of a model based on the mechanism of capillary pore diffusion, assuming that solute spherical molecules pass through an array of solvent-filled cylindrical pores with a diffusive permeation corrected for friction and steric hindrances. Additionally, resistances to the mass transfer were taken into account. Convective permeation data were discussed in terms of morphological properties of the polymeric membranes, molecular Stokes radius, and solute-membrane interactions according to information given by contact angle measurements. The observed steady-state hydraulic permeance of PS-HFMs was 0.972 L/m2hmbar, about 15.6-fold lower than that measured for PES-HFMs (15.2 L/m2h); in general, PS-HFMs provided a significant hindrance to the transport of target species. Diffusion coefficients of metabolites were found to be similar to the corresponding values in water through PES-HFMs, but significantly reduced through PS-HFMs (D(Glucose)(Membrane)=2.8x10(-6)+/-0.6x10(-6)cm2/s, D(BSA)(Membrane)=6.4 x 10(-7)+/-1 x 10(-7)cm(/s, D(Apotransferrin)(Membrane)=2.3 x 10(-7)+/-0.25 x 10(-7)cm2/s).

  14. Amikacin Pharmacokinetics/Pharmacodynamics in a Novel Hollow-Fiber Mycobacterium abscessus Disease Model.

    Science.gov (United States)

    Ferro, Beatriz E; Srivastava, Shashikant; Deshpande, Devyani; Sherman, Carleton M; Pasipanodya, Jotam G; van Soolingen, Dick; Mouton, Johan W; van Ingen, Jakko; Gumbo, Tawanda

    2015-12-07

    The treatment of pulmonary Mycobacterium abscessus disease is associated with very high failure rates and easily acquired drug resistance. Amikacin is the key drug in treatment regimens, but the optimal doses are unknown. No good preclinical model exists to perform formal pharmacokinetics/pharmacodynamics experiments to determine these optimal doses. We developed a hollow-fiber system model of M. abscessus disease and studied amikacin exposure effects and dose scheduling. We mimicked amikacin human pulmonary pharmacokinetics. Both amikacin microbial kill and acquired drug resistance were linked to the peak concentration-to-MIC ratios; the peak/MIC ratio associated with 80% of maximal kill (EC80) was 3.20. However, on the day of the most extensive microbial kill, the bacillary burden did not fall below the starting inoculum. We performed Monte Carlo simulations of 10,000 patients with pulmonary M. abscessus infection and examined the probability that patients treated with one of 6 doses from 750 mg to 4,000 mg would achieve or exceed the EC80. We also examined these doses for the ability to achieve a cumulative area under the concentration-time curve of 82,232 mg · h/liter × days, which is associated with ototoxicity. The standard amikacin doses of 750 to 1,500 mg a day achieved the EC80 in ≤ 21% of the patients, while a dose of 4 g/day achieved this in 70% of the patients but at the cost of high rates of ototoxicity within a month or two. The susceptibility breakpoint was an MIC of 8 to 16 mg/liter. Thus, amikacin, as currently dosed, has limited efficacy against M. abscessus. It is urgent that different antibiotics be tested using our preclinical model and new regimens developed.

  15. Hollow fiber membrane modification with functional zwitterionic macromolecules for improved thromboresistance in artificial lungs.

    Science.gov (United States)

    Ye, Sang-Ho; Arazawa, David T; Zhu, Yang; Shankarraman, Venkat; Malkin, Alexander D; Kimmel, Jeremy D; Gamble, Lara J; Ishihara, Kazuhiko; Federspiel, William J; Wagner, William R

    2015-03-03

    Respiratory assist devices seek optimized performance in terms of gas transfer efficiency and thromboresistance to minimize device size and reduce complications associated with inadequate blood biocompatibility. The exchange of gas with blood occurs at the surface of the hollow fiber membranes (HFMs) used in these devices. In this study, three zwitterionic macromolecules were attached to HFM surfaces to putatively improve thromboresistance: (1) carboxyl-functionalized zwitterionic phosphorylcholine (PC) and (2) sulfobetaine (SB) macromolecules (mPC or mSB-COOH) prepared by a simple thiol-ene radical polymerization and (3) a low-molecular weight sulfobetaine (SB)-co-methacrylic acid (MA) block copolymer (SBMAb-COOH) prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization. Each macromolecule type was covalently immobilized on an aminated commercial HFM (Celg-A) by a condensation reaction, and HFM surface composition changes were analyzed by X-ray photoelectron spectroscopy. Thrombotic deposition on the HFMs was investigated after contact with ovine blood in vitro. The removal of CO2 by the HFMs was also evaluated using a model respiratory assistance device. The HFMs conjugated with zwitterionic macromolecules (Celg-mPC, Celg-mSB, and Celg-SBMAb) showed expected increases in phosphorus or sulfur surface content. Celg-mPC and Celg-SBMAb experienced rates of platelet deposition significantly lower than those of unmodified (Celg-A, >95% reduction) and heparin-coated (>88% reduction) control HFMs. Smaller reductions were seen with Celg-mSB. The CO2 removal rate for Celg-SBMAb HFMs remained comparable to that of Celg-A. In contrast, the rate of removal of CO2 for heparin-coated HFMs was significantly reduced. The results demonstrate a promising approach to modifying HFMs using zwitterionic macromolecules for artificial lung devices with improved thromboresistance without degradation of gas transfer.

  16. Clinical evaluation of the Terumo Capiox FX05 hollow fiber oxygenator with integrated arterial line filter.

    Science.gov (United States)

    Deptula, Joseph; Valleley, Melinda; Glogowski, Kimberly; Detwiler, John; Hammel, James; Duncan, Kim

    2009-12-01

    Perfusion techniques and equipment in pediatric open heart surgery have continued to focus on decreasing prime volumes and lowering surface areas of the cardiopulmonary bypass circuit. While this has improved drastically over the last 20 years, greater demand is being placed on the perfusionist to reduce the deleterious effects of bypass without compromising safety or efficiency. Specifically, manufacturers of disposable perfusion equipment have focused on providing pediatric perfusionists with oxygenators that provide the smallest prime and surface area possible while attempting to maximize performance. Recently,Terumo Cardiovascular has introduced the Capiox FX05, a neonatal hollow fiber oxygenator that includes an integrated arterial line filter. The FX05 provides a blood flow range of 0.1-1.5 L/min and a low priming volume of 43 mL. Additionally, it is coated with X Coating, a biocompatible, hydrophilic polymer surface coating that reduces platelet adhesion and protein denaturation. The purpose of this study was to test the FX05 for gas transfer, blood path resistance, and blood handling characteristics in a standardized clinical setting. Heat exchange coefficients were also calculated during the cooling and warming period. Other data analyzed includes bypass circuit prime volumes and initial patient hematocrit along with the total operative homologous blood donor exposures. In summary, the FX05 offers good gas exchange capabilities and a low pressure drop during normal cardiopulmonary bypass parameters along with the safety of an integrated arterial line filter. Furthermore, the FX05 with integrated filter allows a reduction in overall bypass prime volume and surface area while promoting the reduction of homologous blood transfusions, optimizing hemostasis.

  17. PREPARATION OF ASYMMETRIC POLYETHERKETONE FLAT AND HOLLOW FIBER MEMBRANES FOR GAS SEPARATION USING ACETIC ACID BASED COAGULANTS

    Institute of Scientific and Technical Information of China (English)

    Ji-ping Yang; Philip J. Brown

    2008-01-01

    Membranes for gas separation have developed significantly in the last twenty years, however, there is still a need for high temperature and chemically resistant membranes that exhibit good selectivity and gas permeability. Our study examines the fundamental properties of polyetherketone (PEK, a thermally stable and chemically resistant polymer)membranes prepared using concentrated sulphuric acid (98% H2SO4) as the solvent. Non-solvents used in the work included acetic acid, ethanol, methanol, glycerol, and water. The concentration of the polymer solutions was chosen to be 20%. The membrane structures were examined using SEM, and the gas separation properties were measured using a lab-scale test rig.The results show that formation and control of membrane structures are complicated, and many preparation parameters affect membrane morphology and performance. Using appropriate conditions skinned sponge-like structured hollow fiber membranes could be made from PEK by using acetic acid as the internal coagulant. PEK hollow fibers spun from 20%PEK/H2SO4 solutions with 50% aqueous acetic acid as internal coagulant had selectivity for hydrogen/methane of around 40, implying a solution diffusion separation mechanism for gas separation without the need for fiber coating or after post-treatments.

  18. High-throughput hydrolysis of starch during permeation across {alpha}-amylase-immobilized porous hollow-fiber membranes

    Energy Technology Data Exchange (ETDEWEB)

    Miura, Suguru; Kubota, Noboru; Kawakita, Hidetaka; Saito, Kyoichi E-mail: marukyo@xtal.tf.chiba-u.ac.jp; Sugita, Kazuyuki; Watanabe, Kohei; Sugo, Takanobu

    2002-02-01

    Two kinds of supporting porous membranes, ethanolamine (EA) and phenol (Ph) fibers, for immobilization of {alpha}-amylase were prepared by radiation-induced graft polymerization of an epoxy-group-containing monomer, glycidyl methacrylate, onto a porous hollow-fiber membrane, and subsequent ring-opening with EA and Ph, respectively. An {alpha}-amylase solution was forced to permeate radially outward through the pores of the EA and Ph fibers. {alpha}-Amylase was captured at a density of 0.15 and 6.6 g/L of the membrane by the graft chain containing 2-hydroxyethylamino and phenyl groups, respectively. A permeation pressure of 0.10 MPa provided a space velocity of 780 and 1500 h{sup -1} for the {alpha}-amylase-immobilized EA and Ph fibers, respectively. Quantitative hydrolysis of starch during permeation of a 20 g/L starch solution in the buffer across the {alpha}-amylase-immobilized Ph fiber was attained up to a space velocity of about 2000 h{sup -1}; this was achieved because of negligible diffusional mass-transfer resistance of the starch to the {alpha}-amylase due to convective flow/ whereas an enzyme reaction-controlled system was observed for the {alpha}-amylase-immobilized EA fiber.

  19. High-throughput hydrolysis of starch during permeation across α-amylase-immobilized porous hollow-fiber membranes

    Science.gov (United States)

    Miura, Suguru; Kubota, Noboru; Kawakita, Hidetaka; Saito, Kyoichi; Sugita, Kazuyuki; Watanabe, Kohei; Sugo, Takanobu

    2002-02-01

    Two kinds of supporting porous membranes, ethanolamine (EA) and phenol (Ph) fibers, for immobilization of α-amylase were prepared by radiation-induced graft polymerization of an epoxy-group-containing monomer, glycidyl methacrylate, onto a porous hollow-fiber membrane, and subsequent ring-opening with EA and Ph, respectively. An α-amylase solution was forced to permeate radially outward through the pores of the EA and Ph fibers. α-Amylase was captured at a density of 0.15 and 6.6 g/L of the membrane by the graft chain containing 2-hydroxyethylamino and phenyl groups, respectively. A permeation pressure of 0.10 MPa provided a space velocity of 780 and 1500 h -1 for the α-amylase-immobilized EA and Ph fibers, respectively. Quantitative hydrolysis of starch during permeation of a 20 g/L starch solution in the buffer across the α-amylase-immobilized Ph fiber was attained up to a space velocity of about 2000 h -1; this was achieved because of negligible diffusional mass-transfer resistance of the starch to the α-amylase due to convective flow, whereas an enzyme reaction-controlled system was observed for the α-amylase-immobilized EA fiber.

  20. mJ range all-fiber MOPA prototype with hollow-core fiber beam delivery designed for large scale laser facilities seeding (Conference Presentation)

    Science.gov (United States)

    Scol, Florent; Gouriou, Pierre; Perrin, Arnaud; Gleyze, Jean-François; Valentin, Constance; Bouwmans, Géraud; Hugonnot, Emmanuel

    2017-03-01

    The Laser megajoule (LMJ) is a French large scale laser facility dedicated to inertial fusion research. Its front-ends are based on fiber laser technology and generate highly controlled beams in the nanojoule range. Scaling the energy of those fiber seeders to the millijoule range is a way explored to upgrade LMJ's architecture. We report on a fully integrated narrow line-width all-fiber MOPA prototype at 1053 nm designed to meet stringent requirements of large-scale laser facilities seeding. We achieve 750 µJ temporally-shaped pulses of few nanoseconds at 1 kHz. Thanks to its original longitudinal geometry and its wide output core (26µm MFD), the Yb-doped tapered fiber used in the power amplifier stage ensures a single-mode operation and negligible spectro-temporal distortions. The transport of 30 kW peak power pulses (from tapered fiber) in a 17 m long large mode area (39µm) hollow-core (HC) fiber is presented and points out frequency modulation to amplitude modulation conversion management issues. A S² measurement of this fiber allows to attribute this conversion to a slightly multimode behavior (< 13dB of extinction between the fundamental mode and higher order modes). Other HC fibers exhibiting a really single-mode behavior (<20 dB) have been tested and the comparison will be presented in the conference. Finally, fiber spatial beam shaping from coherent Gaussian beam to coherent top-hat intensity profile beam in the mJ range with a specifically designed and fabricated fiber will also be presented.