Gasoline quality sensor based on tilted fiber Bragg gratings

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOWe report on the study of an intensity-based optical fiber sensor for gasoline quality monitoring. The sensor setup employs two Bragg gratings with different spectral responses to interrogate the optical response of a tilted Bragg grating. The sensor operation is based on the tilted Bragg grating sensitivity to external refractive index changes, which are translated as power variations by the interrogation scheme. Gasoline-ethanol solutions with concentrations ranging from 0% to 60% ethanol were used to demonstrate the sensor performance. The results allowed to estimate that the sensor is able, within its resolution limit, to detect ethanol concentration variations of 1.5% in gasoline-ethanol solutions and discriminate temperature variations of 0.5 degrees C. The all-optical sensor setup is compact and robust, making it a competitive alternative for the realization of fuel quality analyses in practical applications.6218FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO2014/50632-6Sem informaçã

Understanding Lignin-Degrading Reactions of Ligninolytic Enzymes: Binding Affinity and Interactional Profile

Previous works have demonstrated that ligninolytic enzymes mediated effective degradation of lignin wastes. The degrading ability greatly relied on the interactions of ligninolytic enzymes with lignin. Ligninolytic enzymes mainly contain laccase (Lac), lignin peroxidase (LiP) and manganese peroxidase (MnP). In the present study, the binding modes of lignin to Lac, LiP and MnP were systematically determined, respectively. Robustness of these modes was further verified by molecular dynamics (MD) simulations. Residues GLU460, PRO346 and SER113 in Lac, residues ARG43, ALA180 and ASP183 in LiP and residues ARG42, HIS173 and ARG177 in MnP were most crucial in binding of lignin, respectively. Interactional analyses showed hydrophobic contacts were most abundant, playing an important role in the determination of substrate specificity. This information is an important contribution to the details of enzyme-catalyzed reactions in the process of lignin biodegradation, which can be used as references for designing enzyme mutants with a better lignin-degrading activity

A comparison of methods for the extraction of dissolved organic matter from freshwaters

Studies of dissolved organic matter (DOM) composition have used several different methods to concentrate and extract the DOM from fresh water, but the impact of these methods on the composition of the DOM is relatively unknown, as very few studies use more than one method to compare results. The aim of this study was to use several methods, frequently used in the scientific literature, to concentrate and extract DOM from fresh water and compare the elemental and functional group composition of the extracted DOM. In addition, the cost, in terms of money, resources and time, were assessed for each method. The results showed that the elemental and functional group composition of the extracted DOM varied between methods significantly. The methods that yielded the most similar and reproducible DOM results were rotary evaporation, dry-down at 60 °C and freeze-drying. Although each of these methods required a relatively expensive piece of laboratory equipment, this was a ‘one-off’ cost, and consumables and time per sample were relatively low. This study highlights the dangers of comparing DOM data from different studies when the DOM has been extracted via different methods. In future, it is recommended that studies of DOM composition report their methods of extraction clearly and consistently, ideally using one (or more) of the methods showing reliable results here

Molecular dynamics simulation of humic substances

© 2014, Orsi. Humic substances (HS) are complex mixtures of natural organic material which are found almost everywhere in the environment, and particularly in soils, sediments, and natural water. HS play key roles in many processes of paramount importance, such as plant growth, carbon storage, and the fate of contaminants in the environment. While most of the research on HS has been traditionally carried out by conventional experimental approaches, over the past 20 years complementary investigations have emerged from the application of computer modeling and simulation techniques. This paper reviews the literature regarding computational studies of HS, with a specific focus on molecular dynamics simulations. Significant achievements, outstanding issues, and future prospects are summarized and discussed

Trace elements at the intersection of marine biological and geochemical evolution

Life requires a wide variety of bioessential trace elements to act as structural components and reactive centers in metalloenzymes. These requirements differ between organisms and have evolved over geological time, likely guided in some part by environmental conditions. Until recently, most of what was understood regarding trace element concentrations in the Precambrian oceans was inferred by extrapolation, geochemical modeling, and/or genomic studies. However, in the past decade, the increasing availability of trace element and isotopic data for sedimentary rocks of all ages has yielded new, and potentially more direct, insights into secular changes in seawater composition – and ultimately the evolution of the marine biosphere. Compiled records of many bioessential trace elements (including Ni, Mo, P, Zn, Co, Cr, Se, and I) provide new insight into how trace element abundance in Earth's ancient oceans may have been linked to biological evolution. Several of these trace elements display redox-sensitive behavior, while others are redox-sensitive but not bioessential (e.g., Cr, U). Their temporal trends in sedimentary archives provide useful constraints on changes in atmosphere-ocean redox conditions that are linked to biological evolution, for example, the activity of oxygen-producing, photosynthetic cyanobacteria. In this review, we summarize available Precambrian trace element proxy data, and discuss how temporal trends in the seawater concentrations of specific trace elements may be linked to the evolution of both simple and complex life. We also examine several biologically relevant and/or redox-sensitive trace elements that have yet to be fully examined in the sedimentary rock record (e.g., Cu, Cd, W) and suggest several directions for future studies

Glyphosate-Induced Specific and Widespread Perturbations in the Metabolome of Soil Pseudomonas Species

Previous studies have reported adverse effects of glyphosate on crop-beneficial soil bacterial species, including several soil Pseudomonas species. Of particular interest is the elucidation of the metabolic consequences of glyphosate toxicity in these species. Here we investigated the growth and metabolic responses of soil Pseudomonas species grown on succinate, a common root exudate, and glyphosate at different concentrations. We conducted our experiments with one agricultural soil isolate, P. fluorescens RA12, and three model species, P. putida KT2440, P. putida S12, and P. protegens Pf-5. Our results demonstrated both species- and strain-dependent growth responses to glyphosate. Following exposure to a range of glyphosate concentrations (up to 5 mM), the growth rate of both P. protegens Pf-5 and P. fluorescens RA12 remained unchanged whereas the two P. putida strains exhibited from 0 to 100% growth inhibition. We employed a 13C-assisted metabolomics approach using liquid chromatography-mass spectrometry to monitor disruptions in metabolic homeostasis and fluxes. Profiling of the whole-cell metabolome captured deviations in metabolite levels involved in the tricarboxylic acid cycle, ribonucleotide biosynthesis, and protein biosynthesis. Altered metabolite levels specifically in the biosynthetic pathway of aromatic amino acids (AAs), the target of toxicity for glyphosate in plants, implied the same toxicity target in the soil bacterium. Kinetic flux experiments with 13C-labeled succinate revealed that biosynthetic fluxes of the aromatic AAs were not inhibited in P. fluorescens Pf-5 in the presence of low and high glyphosate doses but these fluxes were inhibited by up to 60% in P. putida KT2440, even at sub-lethal glyphosate exposure. Notably, the greatest inhibition was found for the aromatic AA tryptophan, an important precursor to secondary metabolites. When the growth medium was supplemented with aromatic AAs, P. putida S12 exposed to a lethal dose of glyphosate completely recovered in terms of both growth rate and selected metabolite levels. Collectively, our findings led us to conclude that the glyphosate-induced specific disruption of de novo biosynthesis of aromatic AAs accompanied by widespread metabolic disruptions was responsible for dose-dependent adverse effects of glyphosate on sensitive soil Pseudomonas species

Optofluidic device based on a 3D printed chip and a sensing tilted fiber Bragg gratings

In this work an optical solution to characterize optofluidic devices is proposed. The fluidic chip was manufactured via 3D printing and it is able to produce a stream of water droplets in oil. The optical characterization was realized using a Tilted Fiber Bragg Grating (TFBG) embedded in the chip and whose cladding modes could vary between guided and leak. This is the first time a fully integrated all-optical scheme is demonstrated to monitor a droplet generator fluidic device.CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQSem informaçãoSBFoton International Optics and Photonics Conference2018-10-08Campinas, S

In-series Fiber Bragg Gratings And Multimode Interferometers For Sensing Applications

Bragg gratings and multimode interferometers are employed for monitoring strain, refractive index, temperature and liquid level variations. Resolutions of 4.3 μe, 1.6 ° C and 4 x 10-4 RIU were obtained for strain, temperature and refractive index respectively. Liquid level measurements revealed a sensitivity of 0.25 dB/mm. © OSA 2016.Part F1-LAOP 2016Latin America Optics and Photonics Conference, LAOP 201622 August 2016 through 26 August 201613427

Simultaneous measurement of strain, temperature and refractive index based on multimode interference, fiber tapering and fiber Bragg gratings

FINEP - FINANCIADORA DE ESTUDOS E PROJETOSCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOWe report the development of an optical fiber sensor capable of simultaneously measuring strain, temperature and refractive index. The sensor is based on the combination of two fiber Bragg gratings written in a standard single-mode fiber, one in an untapered region and another in a tapered region, spliced to a no-core fiber. The possibility of simultaneously measuring three parameters relies on the different sensitivity responses of each part of the sensor. The results have shown the possibility of measuring three parameters simultaneously with a resolution of 3.77 mu epsilon, 1.36 degrees C and 5 x 10(-4), respectively for strain, temperature and refractive index. On top of the multiparameter ability, the simple production and combination of all the parts involved on this optical-fiber-based sensor is an attractive feature for several sensing applications.We report the development of an optical fiber sensor capable of simultaneously measuring strain, temperature and refractive index. The sensor is based on the combination of two fiber Bragg gratings written in a standard single-mode fiber, one in an untapered region and another in a tapered region, spliced to a no-core fiber. The possibility of simultaneously measuring three parameters relies on the different sensitivity responses of each part of the sensor. The results have shown the possibility of measuring three parameters simultaneously with a resolution of 3.77 mu epsilon, 1.36 degrees C and 5 x 10(-4), respectively for strain, temperature and refractive index. On top of the multiparameter ability, the simple production and combination of all the parts involved on this optical-fiber-based sensor is an attractive feature for several sensing applications.27716FINEP - FINANCIADORA DE ESTUDOS E PROJETOSCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFINEP - FINANCIADORA DE ESTUDOS E PROJETOSCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO01.12.0393.00Sem informaçãoThis work was funded by FINEP (#01.12.0393.00) and by FCT-Fundação para a Ciência e Tecnologia through Portuguese national funds PEstOE/EEI/LA0008/2013 and UID/EEA/50008/2013 (Swat), PhD Scholarship SFRH/BD/88472/2012, investigator grant IF/01664/2014 and project INITIATE. J H Osório acknowledges CNPq for financial support

Intensity liquid level sensor based on multimode interference and fiber Bragg grating

FINEP - FINANCIADORA DE ESTUDOS E PROJETOSCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOIn this paper an intensity liquid level sensor based on a single-mode-no-core-single-mode (SMS) fiber structure together with a Bragg grating inscribed in the later single mode fiber is proposed. As the no-core fiber is sensitive to the external refractive index, the SMS spectral response will be shifted related to the length of no-core fiber that is immersed in a liquid. By positioning the FBG central wavelength at the spectral region of the SMS edge filter, it is possible to measure the liquid level using the reflected FBG peak power through an intensity-based approach. The sensor is also self-referenced using the peak power of another FBG that is placed before and far from the sensing part. The temperature error analysis was also studied revealing that the sensor can operate in environments where the temperature changes are minimal. The possibility to use a second setup that makes the whole device temperature insensitive is also discussed.In this paper an intensity liquid level sensor based on a single-mode-no-core-single-mode (SMS) fiber structure together with a Bragg grating inscribed in the later single mode fiber is proposed. As the no-core fiber is sensitive to the external refractive index, the SMS spectral response will be shifted related to the length of no-core fiber that is immersed in a liquid. By positioning the FBG central wavelength at the spectral region of the SMS edge filter, it is possible to measure the liquid level using the reflected FBG peak power through an intensity-based approach. The sensor is also self-referenced using the peak power of another FBG that is placed before and far from the sensing part. The temperature error analysis was also studied revealing that the sensor can operate in environments where the temperature changes are minimal. The possibility to use a second setup that makes the whole device temperature insensitive is also discussed.271216FINEP - FINANCIADORA DE ESTUDOS E PROJETOSCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFINEP - FINANCIADORA DE ESTUDOS E PROJETOSCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO01.12.0393.00Sem informaçãoThis work was funded by FINEP (#01.12.0393.00) and by FCT-Fundação para a Ciência e Tecnologia through portuguese national funds PEstOE/EEI/LA0008/2013 and UID/EEA/50008/2013 (Swat), PhD Scholarship SFRH/BD/88472/2012, investigator grant IF/01664/2014 and project INITIATE. J H Osório acknowledge CNPq for financial support