494 research outputs found
Visible WDM System Design for Multi-Gbit/s Transmission over SI-POF
This proceeding at: SPIE Photonics West 2015. IX Conference Broadband Access Communication Technologies (SPIE).In order to increase the data rates of Multi-Gbit/s links based on large core step index (SI) plastic optical fibers (POF), different modulation scenes have been proposed. Another option is to use multiple optical carriers for parallel transmission of communication channels over the same fiber. Some designs to reach data rates of 14.77 Gb/s in 50 m, with 4 channels have been developed by off line processing. In this work, designs to test the potential of real Multi- Gbit/s transmission systems using commercial products are reported. Special care in designing low insertion loss multiplexers and demultiplexers is carried out to allow for greener solutions in terms of power consumption.This work has been sponsored by the Spanish institutions Ministerio de EconomĂa y Competitividad under project TEC2012-37983-C03-02, Comunidad de Madrid under grant S2013/MIT-2790.Publicad
Efficient Multiplexer/Demultiplexer for Visible WDM Transmission over SI-POF Technology
A five channel step index plastic optical fiber proposal for a multiplexer/demultiplexer having insertion losses (IL) of 2.9-4 dB, pass bandwidths at -3 dB > 30 nm, crosstalk attenuation >30 dB and size of
similar to ~65
mm x 55 mm, is demonstrated. It is based on a reflective diffraction grating
with blazed profile and an aspheric lens. The theoretical analysis presented is
used to further reduce the system size to similar to ~37 mm x 30 mm and to
increase the number of channels to 8 keeping ILs < 4.5 dB. Experimental
results have good agreement with theoretical expectations.This work was supported by the Spanish Ministry of Economy and by Madrid region under Grants TEC2012-37983-C03-02 and P2013/MIT-2790.Publicad
Visible WDM system for real-time multi-Gb/s bidirectional transmission over 50-m SI-POF
We report a 2 Gb/s bidirectional real-time data transmission with bit error rate (BER) < 1 x 10(-10) in a 50 m step-index polymer optical fiber link. The system is able to transmit 5 Gb/s using five channels. The system performance is tested using the most restrictive channels with the shortest and longest wavelengths in a real-time Ethernet link. The implementation takes an advantage of the PAM-16 modulation spectral efficiency and low loss multiplexers and demultiplexers, which provide an enhanced link power budget. The optical power per transmitted bit considering the BER implication for TCP/IP networks throughput is below 5.8 pJ/b. This is due to the low insertion losses <4 dB, in each five-channel multiplexer and demultiplexer.This work was supported in part by the Spanish Ministry of Economy under Grants TEC2012-37983-C03-02 and TEC2015-63826-C3-2-R, and in part by Madrid Region under Grant S2013/MIT-2790
Polymer Optical Fiber Temperature Sensor With Dual-Wavelength Compensation of Power Fluctuations
The design and development of a plastic optical fiber macrobend temperature sensor is presented. The sensor can operate in a temperature range from -55 to 70 degrees C and has a linear response versus temperature with a sensitivity of 8.95.10(-4) degrees C-1. The sensor system uses the ratio of transmittance at two wavelengths to implement a self-referencing technique in order to avoid undesirable power fluctuations influence. The transmittance ratio precision is 0.1%. An analysis has been developed to find the two wavelengths which ratio offers the highest linearity and sensitivity response. Experimental results are successfully compared with theoretical approaches.This work was supported by the Spanish Ministry of EconomĂa y Competitividad and Madrid region under Grants TEC2012â37983-C03â02, P2013/MIT-2790.Publicad
Memory function on dielectric relaxation
[EN] The second-order memory function ~SOMF! for the dicyclohexylmetyl-2metyl succinate is obtained
by using simple numerical manipulation of the experimental dielectric data. According to the
prescription given in a previous paper @J. Chem. Phys. 109, 9057 ~1998!#, the frequency behavior of
the real and imaginary parts of the SOMF is discussed in terms of the Havriliak-Negami equation
of the dielectric function, and together with the three-variable model describing the evolution of the
torque-autocorrelation function. Furthermore, in this paper we present the temperature dependence
of the parameters, which characterize the SOMF behavior for two ester substances. © 2000
American Institute of Physics. @S0021-9606~00!51048-4#This work was supported in part by the UPV. One of the authors L. F del C. wishes to thank DGAPA-UNAM for support from Grant No. IN119200. Authors of the UPV also thank the Science and Technology Office of Spain for Grant No. MAT 1999-1127-C04-03.DĂaz-Calleja, R.; GarcĂa BernabĂ©, A.; Sanchis SĂĄnchez, MJ.; Del Castillo, L. (2000). Memory function on dielectric relaxation. The Journal of Chemical Physics. 113(24):11258-11263. https://doi.org/10.1063/1.1326913S11258112631132
Diffraction grating-based demultiplexers for SI-POF networks
The proceeding at: 22nd International Conference on Plastic Optical Fibers (POF 2013), took place in 2013 September,11-13, in Armação dos Buzios, Rio de Janeiro, (Brasil). The event Web site at: http://www.pof2013.org.br/ .In this paper, the possibility of implementing low-loss demultiplexer devices based on diffractive
elements for SI-POF networks is studied. Theoretical and experimental analyses of three different diffractive
setups are reported. It is also presented a 3-channel demultiplexer proposal, based on a transmission diffraction
grating, with experimental insertion loss from 3.6dB to 5.8dB and adjacent channel crosstalk from â16.4dB to
â28.6dB. This proposal presents low losses and low crosstalk, and it is very easy to implement in a compact
reflective setup.This work has been sponsored by Ministerio de Economia y Competitividad (TEC2012-37983-C03-02) and
Ministerio de Educacion, Cultura y Deportes (PRX12/00007),Publicad
Educational interventions by nurses in caregivers with their elderly patients at home
Introduction: The home is the natural setting for the development of informal care. The work
that nurses are required to develop in this context (the carer/the elderly dependent/the home)
focuses on training and educational activities to assist these two groups, such as demonstrating
care activities to help dependent seniors, instruction in self-care techniques and teaching strategies
for the use of human and material resources. Aims: This article analyzes care education
interventions performed by nurses, and the factors that facilitate, or limit, health care training.
Methodological approach: This is a qualitative, descriptive study designed to be flexible and
openly analytical in its approach to the research problem and the dynamic nature of the home
environment. Triangulation of the methodological techniques and study subjects was applied.
Results: Nursing interventions related to professional attitudes, such as encouraging communication
and facilitating teaching; communication interventions in health education and
counseling; and technical interventions aimed at improving access to health information
and support for the informal carer. Lack of will, the advanced age of the carer, emotional state
and work overload are factors that undermine care instruction, which if reversed, would become
learning facilitators. The lack of time and resources in the home are the major limiting factors
on care teaching, according to nurses. Evidence from our study suggests that care in the home is
considered a key primary health care strategy, one in which nurses play a significant role.Funding for open access charge: Universidad de Huelva / CBU
Multicomponent bioactive extract from red stage Haematococcus pluvialis wet paste: avoiding the drying step and toxic solvents
info:eu-repo/grantAgreement/AEI/Plan Estatal de InvestigaciĂłn CientĂfica y TĂ©cnica y de InnovaciĂłn 2013-2016/EQC2018-005011-P/ESThis study provides an efficient alternative by extracting bioactive compounds from Haematococcus pluvialis via matrix solid-phase dispersion (MSPD) from its wet form, reducing one of the process steps with the greatest economic impact, the drying of the microalga. To obtain a suitable extract for nutraceutical purposes, solvents with the generally recognised as safe (GRAS) designation (ethanol, ethyl lactate, and ethyl acetate) with limitations of use (acetone) and extractants with higher toxicity such as methanol and methyl-tert-butyl ether (MTBE) are contrasted. Through the optimisation of the extractive process, ethanol, a GRAS solvent, presents the best overall recovery for carotenoid compounds and fatty acids, showing an antioxidant activity of 1.58 mmolTE gâ1 DW, comparable to its synthetic alternative of petrochemical origin without the drawback of having limitations in its food use. In addition, the identification of the phenolic compounds, phloroglucinol, p-coumaric acid, gallic acid, and catechin, not previously characterised in red stage H. pluvialis, provides a response to the phenolic activity present in the extract (24.65 mmolGAE gâ1 DW). Comparison of the extractive efficiency obtained with the main methods for the extraction of carotenoids and fatty acids in H. pluvialis, in contrast to the proposed method, shows a positive feasibility of this approachOpen Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This research was funded by project ED431 2020/06 (Galician Competitive Research Groups Xunta de Galicia). This work was supported by project EQC2018-005011-P (Ministry of Science, Innovation and Universities, Spain). All these programmes are co-funded by FEDER (EU). This article is based upon work from the Sample Preparation Study Group and Network, supported by the Division of Analytical Chemistry of the European Chemical SocietyS
Design and analysis of a WDM System for Multi-Gbit/s Transmission over 50 m of SI-POF
Proceeding of: 23rd International Conference on Plastic Optical Fibers (POF 2014), 8-10 October 2014, Yokohama, JapanIn this work, the design of a data communication system based on a stepâindex plastic optical fiber
link (SIâPOF) and a 3 channel wavelength division multiplexing (WDM) scheme is presented. New proposals
of multiplexer and demultiplexer devices are also presented. The multiplexer is able to combine 3 channels with
insertion loss (IL) of about 1.4 dB. And the demultiplexer is a compact device based on a reflective diffraction
grating that is able to separate 3 channels with IL < 4.5 dB and crosstalk < â30dB. The system has been experimentally
analyzed using one of the 3 channels available (at 650 nm) and the early results are presented. These
results show that the system can establish a real time link at 1 Gbit/s with 50 m of SIâPOF and that it has the
potential of expanding the transmission data rate up to 3 Gbit/s.This work has been sponsored by the Spanish Economy Ministry through grant (Ref.TEC2012-37983-C03-02)
Valorization of insulation cellulose waste as solid biomass fuel
This paper investigates the ability of insulation cellulose fiber powder (CFP) to be pelletized for its valorization as biomass fuel. CFP is a waste originating from insulation cellulose manufacturing that lacks any method of valorization because of its boron salts content. A sugar byproduct and lignosulfonate (LS) were considered as binders for the pellet manufacturing process. Physical tests were carried out to characterize the pelletsâ performance. Chemical and combustion tests were considered to state the pelletsâ potential as a green energy source. Raw CFP showed good ability in its pelletization and durability in the range of 15â30% of moisture content. The pelletâs density decreased as water content increased. Binders increased the pelletâs length before and after the durability test. Binders also increased the CFP pelletâs water absorption, demonstrating a potential decrease in durability against environmental factors. Binders also decreased the lower heating value. Ultimate analysis showed a slight Nitrogen increase in both binder combinations that could potentially raise the pollutant NOx combustion emissions. All the combinations showed adequate combustion characteristics, but binders increased ash production. Additives decreased the CFP volatile matter content and increased the fixed carbon, which could facilitate a more stable combustion. DTA curves showed a mass loss rate decrease in the volatile stage for the binder combinations, which also could be considered as an indicator of a more stable combustion. The ashesâ chemical compositions when analyzed by XPS showed boron contents oscillating between 10.03% and 16.42%, demonstrating the possibility of recovering them from the combustion ashes.This work was funded by Gobierno de Navarra and Fondo Europeo de Desarrollo Regional (FEDER) by the aislamientos ecolĂłgicos para la rehabilitaciĂłn de edificios histĂłricos (Reference: 0011-1365-2018-000096), research project
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