Tunable ring resonator filter for OFDM Transmission systems

A novel tunable filter is theoretically demonstrated. It is based on a ring resonator with an amplifier and a noise filter in the loop. This optoelectronic device has potential as a high-sensitivity receiver and as a tunable demultiplexer in OFDM transmission systems.Publicad

Metal Accumulation by Jatropha curcas L. Adult Plants Grown on Heavy Metal-Contaminated Soil

Jatropha curcas has the ability to phytoextract high amounts of heavy metals during its first months just after seeding. Notwithstanding, there is scarce information about metal uptake by adult J. curcas plants. To shed light on this issue, 4-year-old J. curcas L. plants were planted in a soil mixture of peat moss and mining soil (high metals content), and the biomass growth and metal absorption during 90 days were compared with those of plants growing in peat moss. The main metal found in the mining soil was Fe (31985 mg kg-1) along with high amounts of As (23717 mg kg-1). After the 90-day phytoremediation, the plant removed 29% of Fe and 44% of As from the soil mixture. Results revealed that J. curcas L. translocated high amounts of metals to its aerial parts, so that translocation factors were much higher than 1. Because of the high translocation and bioaccumulation factors obtained, J. curcas L. can be regarded as a hyperaccumulator plant. Despite the great capacity of J. curcas L. to phytoremediate heavy-metal-contaminated soils, the main drawback is the subsequent handling of the metal-contaminated biomass, although some potential applications have been recently highlighted for this biomass.University of Seville (VIPPIT-2019-I.5

Analysis of double-parallel amplified recirculating optical-delay lines

A novel method of analysis of double-parallel amplified recirculating optical-delay lines (DPAROD) is presented. The location of the maxima and the minima of the transfer function for this configuration is calculated and experimentally demonstrated. The influence of different parameters, such as the coupling coefficients, gains, lengths of the fiber loops and fractional losses of the directional couplers, on the shape of the transfer function are analyzed. Different measurements have been taken to verify this model. The potential application of these interconnected delay loops as filters is a reason for developing this method.Publicad

Seguridad en Internet

El presente documento describe los problemas que enfrenta todo usuario en la actualidad con el manejo de la información libre a través del Internet. Específicamente el robo de información. Los datos, información o archivos que son enviados de una PC a otra pueden ser interceptados y leídos por personas no autorizadas. Aquí se menciona la necesidad de diseñar mejores políticas, controles, procedimientos y recomendaciones a los administradores de redes y empresas en general. También se expone el caso de los software dañinos o virus desde sus orígenes hasta las medidas que se pueden tomar para evitarlos. Describe los servicios y mecanismos de seguridad que se deben tomar en cuenta para mejorar la seguridad en la comunicación entre usuarios. Detalla el uso de aplicaciones de correos seguros. Menciona las razones que hace a la aplicación PGP ser la más generalizada y el uso que hace de los diferentes algoritmos para ofrecer mayor seguridad. Resalta la importancia del uso de firmas digitales en los mensajes para protegerlos. Se diseñó una aplicación la cual hace uso del método o cifrado de Vigenere que encripta / desencripta archivos y cadenas de texto

Detection and identification of explosives by surface enhanced Raman scattering

Surface Enhanced Raman Scattering (SERS) has undergone an important development over the last few years, particularly in the detection and identification of extremely low traces of explosives. The large number of studies and results generated by this increasing research makes a comprehensive overview necessary. This work reviews in detail that research focused on the identification of explosives by SERS, including TNT, DNT, RDX, PETN, TATP, HMTD, perchlorate, etc. either in bulk state, in solution or in vapour phase. In brief, TNT and DNT have been widely studied by SERS due to its aromatic structure and LODs down to 5&#-10 zg and 10-17&-10-13 M have been achieved. The other explosives have been quite less researched; therefore, few results are available to be compared and a bit more modest LODs have been reached such as 10-13 M for RDX, 10‑4 M for TATP, 5 pg for PETN, or 10-9 M for perchlorate. In addition, the challenges of detecting both explosives vapours and perchlorate anion by SERS are thoroughly discussed.Prevention of and Fight against Crime Programme European Commission - Directorate-General Home Affair

Detección de fallos con sensores virtuales bajo FF

[Resumen] Se propone la detección de fallos de procesos dotados de elementos de medida virtuales mediante ecuaciones de paridad. El procedimiento de detección utiliza aproximadores funcionales basados en redes neuronales implementadas mediante bloques función del estándar Foundation Fieldbu

Analysis of pre-ignited Improvised Incendiary Devices using portable Raman

In this work, the use of a portable Raman spectrometer is evaluated for the non-invasive analysis of two types of pre-ignited improvised incendiary devices (IIDs), the classic Molotov cocktails and the chemical ignition Molotov cocktails (CIMCs). The most common ignitable liquids (ILs) used to make classic Molotov cocktails (gasoline, diesel fuel, kerosene and ethanol) were measured in seven different clear and colored glass bottles to evaluate if the container features could hamper the Raman measurements. The results showed that the portable Raman spectrometer can be employed to detect ILs in glass bottles without disturbances. Chemical changes on the ILs are produced when they are mixed with acid; therefore, to evaluate the use of the portable Raman spectrometer for the analysis of CIMCs required an investigation of how time and movement influence the measurements. Thus, two different IL&-sulfuric acid mixtures commonly used to make CIMCs (gasoline&-sulfuric acid and diesel fuel&-sulfuric acid) were measured over time under static and motion conditions. In spite of the intense fluorescence encountered in both CIMCs, it was possible to identify the acid and the gasoline for the first hours of the reaction both in the static and motion experiments. Concerning the diesel fuel present in the CIMC, it underwent instantaneous chemical changes under both measurement conditions, showing high fluorescence that impeded its identification. In view of the results achieved, the portable Raman spectrometer can be a useful instrument for the rapid, non-invasive and safe analysis of pre-ignited IIDs

Development of a capillary electrophoresis method for the determination of soybean proteins in soybean-rice gluten-free dietary products. Research Article

CE has been applied for the first time to the simultaneous separation of soybean and\ud rice proteins. Treated and untreated capillaries with different effective lengths as well\ud as separation media at different pHs were tested. For that purpose, samples and\ud standard solutions were prepared in 25:75 ACN–water media containing 0.3% v/v\ud acetic acid. The use of an untreated capillary of 50 cm effective length together with an\ud 80 mM borate buffer (pH 8.5) modified with 20% v/v ACN and UV detection at 254 nm\ud were the conditions working the best. These conditions enabled the determination of\ud soybean proteins in gluten-free dietary commercial products elaborated with soybean\ud protein and/or soybean flour and rice flour using the standard additions calibration\ud method. The method was linear up to 26 mg/mL of soybean proteins, the precision\ud (expressed as RSD) was always better than 6%, and recoveries obtained for soybean\ud proteins when spiking commercial products were very close to 100%The authors thank the Ministry of Science and Technology\ud (Spain) for the research project BQU2002–01199 and F. J.\ud Cabello-Murillo for technical assistance. C.G.-R. also\ud thanks the Ministry of Science and Technology for the\ud Ramón y Cajal program (RYC-2003–001)

Influence of glycerol addition on the droplet size distribution, mean diameters and physical stability of ecological O/W emulsions processed with Microfluidizer technology

The aim of this work was to investigate the influence of the pressure ( 0 psi and 15000 psi) and the number of passes (0,1,2 and 3) through a high pressure homogenizer with Microfluidizer technology on the droplet size distribution, mean diameters and physical stability of ecological O/W emulsions. The results with an emulsion formulated with 50 wt% of glycerol in the continuous phase are compared. As dispersed phase a 30 wt% mixture of green solvents, N,N-dimethyldecanamide and α-pinene with a 75/25 mass ratio was used. In addition, an ecological surfactant derived from coconut oil, HLB = 13.El objetivo de este trabajo ha consistido en investigar cómo influye la presión (0 y 15000 psi) y el número de pasadas (1, 2 y 3) a través de un homogeneizador de alta presión con tecnología Microfluidizer sobre la distribución de tamaños de gota, diámetros medios y estabilidad física de una emulsión ecológica O/W. Se comparan los resultados con la emulsión formulada con un 50% en peso de glicerol en el medio continuo. Como fase dispersa se utiliza un 30% en peso de una mezcla de disolventes verdes, N,N-dimetildecanamida y α-pineno, en una relación en masa de 75/25. Adicionalmente se emplea un tensioactivo ecológico derivado de aceite de coco, de HLB 13.Ministerio de Economía y Competitividad de España-CTQ2015-70700-PComisión Europea (Programa FEDER

Multimode interference filter to solve degradation on coupler common-mode rejection

After quantifying degradation of a common mode rejection ratio (CMRR) 3dB-coupler due to excitation of TE01 mode, a novel compact circuit including multimode interference (MMI) coupler+bend+MMI+filter (CBF) is proposed. We show a CBF circuit has better CMRR at the expense of moderate loss. A complete tolerance analysis to main geometrical parameters has also been carried out.Publicad