Search results for "Fiber"
showing 10 items of 2343 documents
Macroelement Model for In-Plane and Out-of-Plane Responses of Masonry Infills in Frame Structures
2018
A new macroelement model is presented in this paper for the simulation of the in-plane (IP) and out-of-plane (OOP) response of infilled frames subjected to seismic actions. The model consists of two diagonal, one horizontal, and one vertical struts. Each strut is represented by two fiber-section beam-column elements. The model is able to capture the arching action of the wall under an OOP load as well as the interaction between the IP and OOP actions. The proposed modeling approach is sufficiently simple and efficient that it can be used for the static or dynamic analysis of an entire structural system. An experimental validation has been carried out. A further numerical study performed wit…
Mass Transport Analysis of the Enhanced Buffer Capacity of the Bicarbonate-CO2 Buffer in a Phase-Heterogenous System: Physiological and Pharmaceutica…
2018
The bicarbonate buffer capacity is usually considered in a phase-homogeneous system, at equilibrium, with no CO2 transfer between the liquid buffer phase and another phase. However, typically, an in vitro bicarbonate buffer-based system is a phase-heterogeneous system, as it entails continuously sparging (bubbling) the dissolution medium with CO2 in a gas mixture, at constant ratio, to maintain a constant partial pressure of CO2 (g) and CO2(aq) molarity at a prescribed value, with CO2 diffusing freely between the gas and the aqueous phases. The human gastrointestinal tract is also a phase-heterogeneous system, with CO2 diffusing across the mucosal membrane into the mesenteric arterial blood…
Design av en offshore gangbru i fiberarmert polymer
2018
Masteroppgave bygg BYG508 - Universitetet i Agder 2018 Innovation and development are essential for a market in demand of faster, lighter and stronger solutions. As a material with high strength to weight ratio, and good possibilities of being premade, fiber reinforced polymers can meet those requirements. However, it has yet to challenge concrete, steel and aluminum as a structural material. This is the underlying challenge for the problem statement of this assignment, to construct an offshore gangway using fiber reinforced polymers. The design concept is based on existing steel and aluminum constructions within the size range of 25- 30m fully extended. To solve the problem and answer the …
Microfluidic Fabrication of Physically Assembled Nanogels and Micrometric Fibers by Using a Hyaluronic Acid Derivative
2017
The employ of a hyaluronic acid (HA) derivative, bearing octadecyl (C18) and ethylenediamine (EDA) groups, for microfluidic fabrication of nanogels and microfibers is reported in this study. Two HA-EDA-C18 derivatives (125 and 320 kDa) having ionic strength sensitive properties are synthesized and characterized. The control of the rheological properties of HA-EDA-C18 aqueous dispersions by formation of inclusion complexes with hydroxypropyl-β-cyclodextrins (HPCD) is described. Reversibility of C18/HPCD complexation and physical crosslinking is detected in media with different ionic strength through oscillation frequency tests. HA-EDA-C18 125 kDa is employed for nanogel fabrication. Control …
Spectral properties and lifetime of green emission in γ-ray irradiated bismuth-doped silica photonic crystal fibers
2018
Abstract We report an experimental investigation focused on the green emission detected in γ-ray irradiated Bismuth-doped photonic crystal fibers. Our photoluminescence spectra, recorded at room temperature, provide evidence for the presence of two emission bands both located at ~ 530 nm (2.34 eV). One emission is detected only in the Bi-doped core while the other, is detected in the cladding. These two emissions feature different excitation spectra and a fast and a slow decay lifetime. The origin of the fast emission decay, about ten nanoseconds, is tentatively attributed to a silica intrinsic defect, whereas the slow component, having lifetime of about 2 μs and featuring anti-stokes emiss…
Poly-l-Lactic Acid Nanofiber-Polyamidoamine Hydrogel Composites: Preparation, Properties, and Preliminary Evaluation as Scaffolds for Human Pluripote…
2016
Electrospun poly-l-lactic acid (PLLA) nanofiber mats carrying surface amine groups, previously introduced by nitrogen atmospheric pressure nonequilibrium plasma, are embedded into aqueous solutions of oligomeric acrylamide-end capped AGMA1, a biocompatible polyamidoamine with arg-gly-asp (RGD)-reminiscent repeating units. The resultant mixture is finally cured giving PLLA-AGMA1 hydrogel composites that absorb large amounts of water and, in the swollen state, are translucent, soft, and pliable, yet as strong as the parent PLLA mat. They do not split apart from each other when swollen in water and remain highly flexible and resistant, since the hydrogel portion is covalently grafted onto the …
Structural performances of pultruded GFRP emergency structures – Part 1: Experimental characterization of materials and substructure
2019
Abstract This paper presents an experimental study in the field of structures made of pultruded fiber reinforced polymers (FRP) elements to be used for emergency purposes. A preliminary design of a 3D pultruded glass fiber reinforced polymer structure is presented with the mechanical characterization of the constituting elements. The axial and flexural properties of laminate and I-shaped GRFP profiles are discussed considering the short term creep. In a companion paper, the benefits, the limits and the reliability of the structure analyzed for emergency applications are discussed. In details, the numerical structural analysis of the full-scale 3D model is described followed by the experimen…
ALD thin ZnO layer as an active medium in a fiber-optic Fabry–Perot interferometer
2015
Abstract A novel optical fiber sensor of temperature using a thin ZnO layer fabricated by atomic layer deposition (ALD) is demonstrated for the first time. The thin ZnO layer was grown on the face of a standard optical telecommunication fiber SMF-28 and operates as a Fabry–Perot interferometer sensitive to temperature. The interferometer characterization was made in the temperature range extending from 50 to 300 °C with resolution equal to 1 °C. The output signal was analyzed by measurement of the shift of the maxima in spectral pattern. The sensitivity of temperature measurement is about 0.05 nm/°C. Furthermore, very good linearity of the sensor was achieved with correlation coefficient R2…
Broadband tuning of a long-cavity all-fiber mode locked Thulium-doped fiber laser using an acousto-optic bandpass filter
2019
A long-cavity passively mode-locked thulium-doped all-fiber laser is reported incorporating a tapered acousto-optic tunable bandpass filter (AOTBF). The operation of the AOTBF relies on the intermodal coupling between core and cladding modes when a flexural acoustic wave propagates along an 80-microm tapered fiber. The filter works in transmission and exhibits a 3-dB bandwidth of 9.02 nm with an insertion loss of 3.4 dB. The laser supports ultrashort pulse generation at a low repetition rate of 784.93 kHz. Optical pulses with 2.43 nm of optical bandwidth and 2.1 ps pulse duration were obtained in a broad tuning range from 1824.77 to 1905.16 nm.
Effect of silane coupling treatment on the adhesion between polyamide and epoxy based composites reinforced with carbon fibers
2020
The increasing efforts aimed to design structures with reduced weight and better mechanical performances has led in recent years to a growing use of fiber reinforced polymer materials in several fields such as marine. However, these materials can be composed of chemically very different elements and, hence, may be difficult to joint. This research aims to improve the adhesion between a thermoplastic matrix of polyamide reinforced with short carbon fibers (PA12-CR) and a carbon fiber reinforced epoxy matrix (CFRP). Two different silane coupling agents, (3-Aminopropyl)trimethoxysilane (AM) and (3-Glycidyloxypropyl)trimethoxysilane (EP), were applied, through the spray deposition method, on th…