Read by QxMD icon Read


Matteo Cavasin, Marco Sangermano, Barry Thomson, Stefanos Giannis
An innovative testing methodology to evaluate the effect of long-term exposure to a marine environment on Glass Fiber Reinforced Polymers (GFRPs) has been investigated and is presented in this paper. Up to one-year ageing was performed in seawater, to simulate the environment for offshore oil and gas applications. The performance of an epoxy and epoxy-based GFRP exposed at different temperatures from 25 to 80 °C was quantified. The materials were also aged in dry air, to de-couple the thermal effect from the seawater chemical action...
March 8, 2019: Materials
Xi Liu, Yijia Sun, Tao Wu
Adding fibers is highly effective to enhance the deflection and ductility of fiber-reinforced polymer (FRP)-reinforced beams. In this study, the stress and strain conditions of FRP-reinforced lightweight aggregate concrete (LWC) beams with and without fibers at ultimate load level were specified. Based on the sectional analyses, alternative equations to predict the balanced reinforcement ratio and flexural capacity for beams failed by balanced failure and concrete crushing were established. A rational equation for estimating the short-term stiffness of FRP⁻LWC beams at service-load levels was suggested based on Zhu's model...
February 20, 2019: Sensors
Yujun Qi, Lei Xie, Yu Bai, Weiqing Liu, Hai Fang
An innovative pultruded fiber reinforced polymer (FRP)⁻wood composite (PFWC) column with a lightweight southern pine wood core confined by outer FRP sheets was manufactured using an improved pultrusion process. Axial compression tests with both ends pinned as boundary conditions were employed to investigate the mechanical performance of such PFWC columns under concentric load. Through experimental investigations, the effects of the slenderness ratio on the failure modes and the axial load bearing capacities of the PFWC columns were evaluated...
February 13, 2019: Sensors
Jin-Woo Kim
In this study, effects of variations in the fiber orientation for GFRP tension test on strength and temperature distributions were experimentally investigated. The temperature measurement method for test specimen was proposed in an IR thermography. Lock-in method, which is one of technique in IR thermography to measure the temperature of specimen as a function of time, was utilized to monitor changes in the temperature distribution during crack propagation process. At the maximum stress point, the temperature was significantly increased...
July 1, 2019: Journal of Nanoscience and Nanotechnology
Dong-Gi Lee, Jin-Woo Kim
In this study, materials with each different fiber content ratio and fiber orientation state were used in the study for the decision of molding condition of GFRP and the condition of lap joint. Clarify joint strength and lap joint efficiency during high temperature and compression press lap joint molding of GFRP and research data regarding the lap length of the joint part was presented. Thus, the purpose of this study is to contribute to the substitution of existing products as well as usage development in the non-automobile field and also to find out precise dynamic characteristics as designing data of structures...
July 1, 2019: Journal of Nanoscience and Nanotechnology
Cristian Marro Bellot, Marco Sangermano, Massimo Olivero, Milena Salvo
Optical fiber sensors (OFSs), which rely on evanescent wave sensing for the early detection of the diffusion of water and hydrochloric acid through glass fiber-reinforced polymers (GFRPs), have been developed and tested. Epoxy and GFRP specimens, in which these sensors were embedded, were subjected to tests in artificial sea water and hydrochloric acid. The sensors were able to detect the diffusion of chemicals through the epoxy and GFRP samples on the basis of a drop in the reflected signal from the tip of the optical sensor probe...
January 25, 2019: Materials
Christian Leopold, Sergej Harder, Timo Philipkowski, Wilfried V Liebig, Bodo Fiedler
Common analytical models to predict the unidirectional compressive strength of fibre reinforced polymers are analysed in terms of their accuracy. Several tests were performed to determine parameters for the models and the compressive strength of carbon fibre reinforced polymer (CFRP) and glass fibre reinforced polymer (GFRP). The analytical models are validated for composites with glass and carbon fibres by using the same epoxy matrix system in order to examine whether different fibre types are taken into account...
December 11, 2018: Materials
Punita Kumari, Jihui Wang, Saahil Khan
The effect of multiple/repeated impacts on a repaired composite was investigated using a low-velocity impact test. The composite samples were fabricated through a vacuum resin infusion method (VARI) and repaired by a scarf repair technique. Later, a repeated low-velocity impact test was performed on the original and repaired composites samples. Performance of the multi-impacted repaired and original samples was evaluated and compared by measuring maximum contact force, maximum displacement, maximum time duration, absorbed energy and damage area...
November 22, 2018: Materials
Ying Wang, Lars P Mikkelsen, Grzegorz Pyka, Philip J Withers
Understanding the fatigue damage mechanisms in composite materials is of great importance in the wind turbine industry because of the very large number of loading cycles rotor blades undergo during their service life. In this paper, the fatigue damage mechanisms of a non-crimp unidirectional (UD) glass fibre reinforced polymer (GFRP) used in wind turbine blades are characterised by time-lapse ex-situ helical X-ray computed tomography (CT) at different stages through its fatigue life. Our observations validate the hypothesis that off-axis cracking in secondary oriented fibre bundles, the so-called backing bundles, are directly related to fibre fractures in the UD bundles...
November 21, 2018: Materials
Anne Laprie, Valérie Bernier, Christian Carrie
No abstract text is available yet for this article.
October 22, 2018: Radiotherapy and Oncology: Journal of the European Society for Therapeutic Radiology and Oncology
Yiwei Xia, Xiaoping Li, Yu Peng, Mianheng Lai, Lu Wang
In recent years, load-bearing exterior sandwich wall boards have been adopted in civil engineering. The exterior walls of structures are often exposed to low velocity impacts such as stones, tools, and windborne debris, etc. The ultimate loading capacity, deformation, and ductility of sandwich walls are weakened by impact loads. In this study, the sandwich wall boards consisted of glass fiber reinforced plastic (GFRP) face sheets and a web-foam core. The core of wall boards was not the isotropic material. There was no doubt that the mechanical performance was seriously influenced by the impact locations...
September 13, 2018: Materials
Kai Xu, Changchun Ren, Qingshan Deng, Qingping Jin, Xuemin Chen
Glass fiber-reinforced polymers (GFRPs) have received increasing attention in recent years due to their overall performance of light weight, low cost and corrosion resistance, and they are increasingly used as reinforcement in concrete structures. However, GFRP material has low elastic modulus and linear elastic properties compared with steel bars, which introduces different bonding characteristics between bars and concrete. Therefore, a reliable monitoring method is urgently needed to detect the bond slip in GFRP-reinforced concrete structures...
August 13, 2018: Sensors
Anne Ducassou, Laetitia Padovani, Leonor Chaltiel, Stéphanie Bolle, Jean-Louis Habrand, Line Claude, Christian Carrie, Xavier Muracciole, Bernard Coche-Dequeant, Claire Alapetite, Stéphane Supiot, Charlotte Demoor-Goldschmidt, Valerie Bernier-Chastagner, Aymeri Huchet, Julie Leseur, Elisabeth Le Prise, Christine Kerr, Gilles Truc, Tan Dat Nguyen, Anne-Isabelle Bertozzi, Didier Frappaz, Sergio Boetto, Annick Sevely, Fatima Tensaouti, Anne Laprie
PURPOSE: The objective of this study was to analyze survival and prognostic factors for children, adolescents, and young adults treated with postoperative radiation therapy (RT) for intracranial ependymoma. METHODS AND MATERIALS: Between 2000 and 2013, 202 patients aged ≤25 years were treated in the 13 main French pediatric RT reference centers. Their medical records were reviewed for information, treatments received, and survival rates. All children had received postoperative RT- conformal, intensity modulated, or proton beam...
September 1, 2018: International Journal of Radiation Oncology, Biology, Physics
Monica J Emerson, Vedrana A Dahl, Knut Conradsen, Lars P Mikkelsen, Anders B Dahl
A unidirectional (UD) glass fibre reinforced polymer (GFRP) composite was scanned at varying resolutions in the micro-scale with several imaging modalities. All six scans capture the same region of the sample, containing well-aligned fibres inside a UD load-carrying bundle. Two scans of the cross-sectional surface of the bundle were acquired at a high resolution, by means of scanning electron microscopy (SEM) and optical microscopy (OM), and four volumetric scans were acquired through X-ray computed tomography (CT) at different resolutions...
June 2018: Data in Brief
Lamia Heikal, Anna Starr, Dania Hussein, Jesus Prieto-Lloret, Phil Aaronson, Lea Ann Dailey, Manasi Nandi
Reduced nitric oxide (NO) bioavailability correlates with impaired cardiovascular function. NO is extremely labile and has been challenging to develop as a therapeutic agent. However, NO bioavailability could be enhanced by pharmacologically targeting endogenous NO regulatory pathways. Tetrahydrobiopterin, an essential cofactor for NO production, is synthesized by GTP cyclohydrolase-1 (GCH1), which complexes with GCH1 feedback regulatory protein (GFRP). The dietary amino acid l-phenylalanine activates this complex, elevating vascular BH4 ...
June 2018: JACC. Basic to Translational Science
Saurabh Gupta, Prabhu Rajagopal
This paper studies the interaction of the fundamental symmetric Lamb wave mode S0 with delaminations in 8-layered glass fibre reinforced polymer (GFRP) laminated composites, using numerical models validated against experiments. The validation is performed using experiments on the eight layer quasi-isotropic GFRP composite laminate [0/90/45/-45]S . Further numerical studies were performed on the laminates [0/45/-45/90]S, [0/45/90/-45]S, [90/45/-45/0]S, [90/-45/0/45]S, [45/-45/0/90]S, and [45/90/-45/0]S to study the effect of ply layups on the reflection of S0 Lamb waves...
November 2018: Ultrasonics
Guanghui Li, Jun Zhao, Zike Wang
Fiber-reinforced polymer (FRP) bars have been widely applied in civil engineering. This paper presents the results of an experimental study to investigate the tensile fatigue mechanical properties of glass fiber-reinforced polymer (GFRP) bars after elevated temperatures exposure. For this purpose, a total of 105 GFRP bars were conducted for testing. The specimens were exposed to heating regimes of 100, 150, 200, 250, 300 and 350 °C for a period of 0, 1 or 2 h. The GFRP bars were tested with different times of cyclic load after elevated temperatures exposure...
June 16, 2018: Materials
Daniel Teufl, Swen Zaremba
During the production of fiber-reinforced composite materials, liquid resin is introduced into the fiber material and cured, i.e., hardened. An elevated temperature is needed for this curing. Microwave curing of composites has been investigated for some time, but it has mostly been done using small domestic or laboratory equipment. However, no investigation has been carried out using an industrial-sized chamber-microwave for glass fiber-reinforced plastic (GFRP). Here, we show that microwave curing produces laminates of the same quality as oven-cured ones...
May 18, 2018: Materials
Michal Dziendzikowski, Patryk Niedbala, Artur Kurnyta, Kamil Kowalczyk, Krzysztof Dragan
One of the ideas for development of Structural Health Monitoring (SHM) systems is based on excitation of elastic waves by a network of PZT piezoelectric transducers integrated with the structure. In the paper, a variant of the so-called Transfer Impedance (TI) approach to SHM is followed. Signal characteristics, called the Damage Indices (DIs), were proposed for data presentation and analysis. The idea underlying the definition of DIs was to maintain most of the information carried by the voltage induced on PZT sensors by elastic waves...
May 11, 2018: Sensors
João Vitor de Queiroz, José Cavalcante Souza Vieira, Grasieli de Oliveira, Camila Pereira Braga, Izabela da Cunha Bataglioli, Janaína Macedo da Silva, Wellington Luiz de Paula Araújo, Pedro de Magalhães Padilha
Predator fish can accumulate high levels of mercury, which qualifies them as potential indicators of this toxic metal. The predatory species Brachyplatystoma filamentosum, popularly known as filhote, is among the most consumed species in the Brazilian Amazon. Continuing the metalloproteomic studies of mercury in Amazonian fishes that have been developed in the last 5 years, the present paper provides the data of protein characterization associated with mercury in muscle and liver samples of filhote (Brachyplatystoma filamentosum) collected in the Madeira River, Brazilian Amazon...
May 8, 2018: Biological Trace Element Research
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"