A two particle hidden sector and the oscillations with photons

We present a detailed study of the oscillations and optical properties for vacuum, in a model for the dark sector that contains axion-like particles and hidden photons. In this model, both can couple to photons. We provide bounds for the couplings versus the mass, using current results from ALPS-I and PVLAS. We also discuss the challenges for the detection of models with more than one hidden particle in light shining trough wall-like experiments.Comment: 23 pages, 7 figures. Figures are coloure

Analytical model for BTEX natural attenuation in the presence of fuel ethanol and its anaerobic metabolite acetate

Copyright © 2013 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Journal of Contaminant Hydrology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Contaminant Hydrology Vol. 146 (2013), DOI: 10.1016/j.jconhyd.2012.12.006Flow-through column studies were conducted to mimic the natural attenuation of ethanol and BTEX mixtures, and to consider potential inhibitory effects of ethanol and its anaerobic metabolite acetate on BTEX biodegradation. Results were analyzed using a one-dimensional analytical model that was developed using consecutive reaction differential equations based on first-order kinetics. Decrease in pH due to acetogenesis was also modeled, using charge balance equations under CaCO3 dissolution conditions. Delay in BTEX removal was observed and simulated in the presence of ethanol and acetate. Acetate was the major volatile fatty acid intermediate produced during anaerobic ethanol biodegradation (accounting for about 58% of the volatile fatty acid mass) as suggested by the model data fit. Acetate accumulation (up to 1.1 g/L) near the source zone contributed to a pH decrease by almost one unit. The anaerobic degradation of ethanol (2 g/L influent concentration) at the source zone produced methane at concentrations exceeding its solubility (≅ 26 mg/L). Overall, this simple analytical model adequately described ethanol degradation, acetate accumulation and methane production patterns, suggesting that it could be used as a screening tool to simulate lag times in BTEX biodegradation, changes in groundwater pH and methane generation following ethanol-blended fuel releases

Experiences Developing Safe and Fault-Tolerant Tele-Operated Service Robots. A Case Study in Shipyards

Human operators use tele-operated service robots for performing more or less hazardous operations (manipulation of heavy and/or dangerous products) in more or less hostile environments (nuclear reactors, space missions, warehouses, etc). Anyway, independently of the operation, the robot has to interact with both the environment it is working on and with human operators. Therefore, it is essential that the design (which include both software and hardware) of the robot involves no risk, or at least an acceptable level of risk, neither for the operators, nor for the environment nor for the robot itself. Nevertheless, it is not always possible to make a system free of failures in its design or operation. Apart from the risk inherent to the use of the mechanisms themselves, these systems work in hazardous environments, where the probability of the risk is higher than normal. Should a failure happen, its consequences could even involve the loss of human lives. (Neumann, 1994) documents many cases of computer-related failures, such as the Therac-25 (a radiation-therapy device), the missiles shield in Saudi Arabia, etc. Nevertheless, safety aspects are seldom included in the early phases of the system design process from the beginning, even though they are a critic aspect. Generally, safety has to conform and adapt to the already designed system and not vice versa, when it is widely known that safety involves not only the design of the software but also the hardware. Even more, a simple hardware solution can eliminate a hazard or simplify the software design in many situations.This research has been funded by the Spanish CICYT project MEDWSA (TIN2006-15175- C05-02) and the Regional Government of Murcia Séneca Program (02998-PI-05)

Nitrate addition to groundwater impacted by ethanol-blended fuel accelerates ethanol removal and mitigates the associated metabolic flux dilution and inhibition of BTEX biodegradation

A comparison of two controlled ethanol-blended fuel releases under monitored natural attenuation (MNA) versus nitrate biostimulation (NB) illustrates the potential benefits of augmenting the electron acceptor pool with nitrate to accelerate ethanol removal and thus mitigate its inhibitory effects on BTEX biodegradation. Groundwater concentrations of ethanol and BTEX were measured 2 m downgradient of the source zones. In both field experiments, initial source-zone BTEX concentrations represented less than 5% of the dissolved total organic carbon (TOC) associated with the release, and measurable BTEX degradation occurred only after the ethanol fraction in the multicomponent substrate mixture decreased sharply. However, ethanol removal was faster in the nitrate amended plot (1.4 years) than under natural attenuation conditions (3.0 years), which led to faster BTEX degradation. This reflects, in part, that an abundant substrate (ethanol) can dilute the metabolic flux of target pollutants (BTEX) whose biodegradation rate eventually increases with its relative abundance after ethanol is preferentially consumed. The fate and transport of ethanol and benzene were accurately simulated in both releases using RT3D with our general substrate interaction module (GSIM) that considers metabolic flux dilution. Since source zone benzene concentrations are relatively low compared to those of ethanol (or its degradation byproduct, acetate), our simulations imply that the initial focus of cleanup efforts (after free-product recovery) should be to stimulate the degradation of ethanol (e.g., by nitrate addition) to decrease its fraction in the mixture and speed up BTEX biodegradation.Petróleo Brasileiro S/A — PETROBRASCoordination of Improvement of Higher Education Personnel (CAPES)National Council for Scientific and Technological Development (CNPq

Modeling benzene plume elongation mechanisms exerted by ethanol using RT3D with a general substrate interaction module

Copyright © 2008 American Geophysical Union (AGU)A mathematical model was developed to evaluate the effect of the common fuel additive ethanol on benzene fate and transport in fuel-contaminated groundwater and to discern the most influential benzene plume elongation mechanisms. The model, developed as a module for the Reactive Transport in 3 Dimensions (RT3D) model, includes commonly considered fate and transport processes (advection, dispersion, adsorption, biodegradation, and depletion of molecular oxygen during biodegradation) and substrate interactions previously not considered (e.g., a decrease in the specific benzene utilization rate due to metabolic flux dilution and/or catabolite repression) as well as microbial population shifts. Benzene plume elongation predictions, based on literature model parameters, were on the order of 40% for a constant source of E10 gasoline (10% vol/vol ethanol), which compares favorably to field observations. For low benzene concentrations (<1 mg/L), oxygen depletion during ethanol degradation was the principal mechanism hindering benzene natural attenuation. For higher benzene concentrations (exerting an oxygen demand higher than the available dissolved oxygen), metabolic flux dilution was the dominant plume elongation process. If oxygen were not limiting, as might be the case in zones undergoing aerobic biostimulation, model simulations showed that microbial growth on ethanol could offset negative substrate interactions and enhance benzene degradation, resulting in shorter plumes than baseline conditions without ethanol

Design proposal of an industrial biodigester of filter-cake for the generation of electrical energy

El presente trabajo está enmarcado en el diseño de una planta de biogás que utiliza cachaza como sustrato. El estudio de los diferentes campos de utilización de biogás y su eficiencia en la generación de electricidad mediante grupos electrógenos. Para el diseño de la planta se han propuesto seis biodigestores industriales y seis grupos electrógenos para una capacidad de generación de 24 MW para la venta de energía eléctrica generando un ingreso 1 756 093,11 $/año. Fueron determinados a partir de la metodología presentada las características constructivas del biodigestor, el volumen de biogás generado, así como la cantidad necesaria para satisfacer la demanda de biogás. El comportamiento a nivel mundial de los principales países productores de biogás ofrece costos de construcción de las plantas por metro cúbico de biogás generado en el orden de 200$ a 500 $. Se determina el potencial de generación de cachaza por la fábrica de azúcar que es de 144 t/d con una capacidad de generación de biogás de 13 038 Nm3 /d. La planta propuesta tiene una capacidad de generación de 24 MWh/d de energía eléctrica suministrada a la red. La evaluación económica de la planta muestra que la inversión de 4 237 000,00$ tiene una Tasa Interna de Retorno (TIR) de un 8% y un Periodo de Recuperación de la Inversión (PRI) de 6 años.The present work is framed in the design of a biogas plant that uses filter-cake as a substrate. The study of the different fields of use of biogas and its efficiency in the generation of electricity through generator sets. For the design of the plant, six industrial biodigesters and six generator sets have been proposed for a generation capacity of 24 MW for the sale of electrical energy generating an income of $1,756,093.11$year. The constructive characteristics of the biodigester, the volume of biogas generated, as well as the amount needed to meet the demand for biogas were determined from the methodology presented. The worldwide performance of the main biogas producing countries offers plant construction costs per cubic meter of biogas generated in the order of $200 to$500. The potential for the generation of filter-cake by the sugar factory is determined to be 144 t/d with a biogas generation capacity of 13 038 Nm3/d. The proposed plant has a generating capacity of 24 MWh/d of electricity supplied to the grid. The economic evaluation of the plant shows that the investment of $4,237,000.00 has an Internal Rate of Return (IRR) of 8% and an Investment Recovery Period (PRI) of 6 years.Campus Lima Su

Detection of Schistosoma mansoni-derived DNA in human urine samples by loopmediated isothermal amplification (LAMP)

[EN]Background Schistosoma mansoni is the main species causing hepatic and intestinal schistosomiasis in Sub-Saharan Africa, and it is the only species in South America. Adult stages of the parasite reside in the mesenteric venous plexus of infected hosts, and eggs are shed in feces. Collecting patient stool samples for S. mansoni diagnostic purposes is difficult in large-scale field trials. Urine samples would be an alternative approach for molecular S. mansoni detection since they have several advantages over stool samples, including better handling, management and storage. Additionally, loop-mediated isothermal amplification (LAMP) technology is a powerful molecular diagnostic tool for infectious diseases, particularly under field conditions in developing countries. The present study aimed to assess the effectiveness of our previously developed LAMP assay (SmMIT-LAMP) for S. mansoni-specific detection in clinical urine samples. Methodology/Principal findings The sensitivity of SmMIT-LAMP in urine was established in simulated fresh human urine samples artificially spiked with genomic DNA from S. mansoni. LAMP for 120 min instead of 60 min improved the sensitivity, reaching values of 0.01 fg/μL. A set of well-defined frozen stored human urine samples collected from Sub-Saharan immigrant patients was selected from a biobank to evaluate the diagnostic validity of SmMIT-LAMP. The set included urine samples from patients with microscopy-confirmed infections with S. mansoni, S. haematobium and other nonschistosome parasites, as well as urine samples from patients with microscopy-negative eosinophilia without a confirmed diagnosis. The SmMIT-LAMP was incubated for 60 and 120 min. A longer incubation time was shown to increase the LAMPpositive results in patient urine samples. We also tested urine samples from mice experimentally infected with S. mansoni, and LAMP-positive results were obtained from the third week after infection. A real-time LAMP assay was also performed with three individual urine samples. Conclusions/Significance The SmMIT-LAMP could effectively detect S. mansoni DNA in mouse urine samples and produced promising results for human clinical samples. The detection of S. mansoni DNA in mouse urine samples from the third week after infection indicates that early diagnosis of active S. mansoni infection is possible using urine as a source of DNA. Further studies are still needed, but our method could be used as a promising molecular tool applicable to urine samples to diagnose human intestinal schistosomiasis caused by S. mansoni

Electrochemical Oscillatory Baffled Reactors Fabricated with Additive Manufacturing for Efficient Continuous-Flow Oxidations

[Image: see text] Electrochemical continuous-flow reactors offer a great opportunity for enhanced and sustainable chemical syntheses. Here, we present a novel application of electrochemical continuous-flow oscillatory baffled reactors (ECOBRs) that combines advanced mixing features with electrochemical transformations to enable efficient electrochemical oxidations under continuous flow at a millimeter distance between electrodes. Different additive manufacturing techniques have been employed to rapidly fabricate reactors. The electrochemical oxidation of NADH, a very sensitive substrate key for the regeneration of enzymes in biocatalytic transformations, has been employed as a benchmark reaction. The oscillatory conditions improved bulk mixing, facilitating the contact of reagents to electrodes. Under oscillatory conditions, the ECOBR demonstrated improved performance in the electrochemical oxidation of NADH, which is attributed to improved mass transfer associated with the oscillatory regime

Fibroelastoma en el ventrículo izquierdo: un hallazgo muy poco frecuente

The evaluation of cardiac masses is a relatively frequent clinical problem for cardiac imaging techniques. We present the case of a cardiac mass with an unusual location in which imaging techniques made it possible to guide the diagnosis, which, how could it be otherwise, was confirmed in surgery.La valoración de las masas cardíacas es un problema clínico relativamente frecuente para las técnicas de imagen cardíca. Presentamos el caso de una masa cardíaca con localización inusual en el que las técnicas de imagen permitieron orientar el diagnóstico, que como no puede ser de otro modo, se confirmó en la cirugía