852 research outputs found
Sistema de encendido de combustible usando celdas Peltier
The objective is to design a power supply system for an electric arc ignition circuit, in a conventional domestic stove, that uses Peltier cells as electric generation source. The regular working conditions of a domestic gas stove were replicated, doing temperature measurements by means of a thermographic camera on the stove surfaces, and by means of a conventional instrument on its inner room. Starting from the measurements, the most appropriate type of Peltier cell was selected, as well as its amount and optimum location. After that, the prototype circuit was design, as for the load of the storage device, as for the electric arc ignition system. A design of a battery-based power supply circuit was obtained, whose energy recharge source is based on Peltier cells, and which has an energy consumption of 650mW. In conclusion, It is possible to use the thermal energy produced by a stove or any other energy dissipating, for supplying power to low-power circuits, taking advantage of the thermoelectric effect.El objetivo es diseñar un sistema de alimentación para un circuito de ignición por arco eléctrico, para una estufa domestica convencional, que utilice celdas Peltier como fuente de generación de energía eléctrica. Se replicaron las condiciones normales de funcionamiento de una estufa a gas doméstica, realizando mediciones de temperatura con una cámara termográfica sobre las superficies de la estufa, y con un medidor convencional sobre su espacio interno. Partiendo de las mediciones realizadas, se seleccionó el tipo de celda Peltier más adecuado, así como también su cantidad y posición óptima. Posteriormente, se procedió a realizar un diseño del circuito prototipo tanto para la carga del dispositivo de almacenamiento como para el sistema de ignición por arco eléctrico. Se obtuvo el diseño de un circuito de alimentación basado en una batería, cuya fuente de recarga de energía está basada en celdas Peltier, teniendo un consumo estimado de 650mW. En conclusión, es posible utilizar la energía térmica producida por una estufa o cualquier otro elemento disipador de energía en forma de calor para alimentar circuitos de baja potencia, aprovechando el efecto termoeléctrico
Validation of hypermethylated DNA regions found in colorectal cancers as potential aging-independent biomarkers of precancerous colorectal lesions
BACKGROUND
We previously identified 16,772 colorectal cancer-associated hypermethylated DNA regions that were also detectable in precancerous colorectal lesions (preCRCs) and unrelated to normal mucosal aging. We have now conducted a study to validate 990 of these differentially methylated DNA regions (DMRs) in a new series of preCRCs.
METHODS
We used targeted bisulfite sequencing to validate these 990 potential biomarkers in 59 preCRC tissue samples (41 conventional adenomas, 18 sessile serrated lesions), each with a patient-matched normal mucosal sample. Based on differential DNA methylation tests, a panel of candidate DMRs was chosen on a subset of our cohort and then validated on the remaining part of our cohort and two publicly available datasets with respect to their stratifying potential between preCRCs and normal mucosa.
RESULTS
Strong statistical significance for the difference in methylation levels was observed across the full set of 990 investigated DMRs. From these, a selected candidate panel of 30 DMRs correctly identified 58/59 tumors (area under the receiver operating curve: 0.998).
CONCLUSIONS
These validated DNA hypermethylation markers can be exploited to develop more accurate noninvasive colorectal tumor screening assays
A graph-based modelling methodology for high-pressure networks applied on waterjet machining
This paper proposes a graph-based methodology that models high-pressure networks of varioustopologies. Therefore, a mathematical modelling of a supply network for waterjet machining will be introduced. High-pressure components are assigned to homogeneous segments, each representing a local pressure state as a differential equation. Segments are subsequently interconnected along the fluid flow path as an algebraic equation that allocates a fluid flow to the interconnections, resulting in a lumped parameter model. For this purpose, a graph network description has been used to approximate the spatially distributed high-pressure system. In this way, the proposed methodology offers a flexible modelling to cope with different network topologies. Moreover, a variable fluid compressibility has also been introduced so that a wide operating range can be included. This modelling methodology has been applied to a supply network for waterjet machining. The resulting mathematical model has been verified by measurements from a test bench with a pressure range of 100 to 400 MPa. It was shown that a variable fluid compressibility improves the model’s accuracy and that modelling errors can be reduced in comparison to other existing methodologies
Impacto social en los comerciantes, por el desarrollo de obras de transmilenio fase III carrera 10 de la ciudad de Bogotá.
Tablas, ficha técnica, imágenesEvaluar el impacto social que tienen las obras de la Fase III de Transmilenio, en los comerciantes ubicados en la Carrera Décima entre calles 19 y 26 de la ciudad de Bogotá, con el fin presentar unas propuestas que sirvan de base, sobre la forma como se puede mitigar el impacto social que generan las obras de infraestructura de la ciudad, sobre la población, en este caso los comerciantes de la Carrera Décima entre calles 19 y 26 de la ciudad de Bogotá. Las propuestas servirán como herramienta para la toma de decisiones en futuras obras a realizar.No Abstrac
Plan estratégico para Alimentos Montecarlo S.A.S. al año 2020 Marca Colandes
58 Páginas.ALIMENTOS MONTECARLO S.A.S. y su marca comercial COLANDES, es una empresa familiar dedicada a la recolección de leche cruda, proceso, producción y comercialización de leche pasteurizada y derivados lácteos en Zipaquirá Cundinamarca. Fue fundada por 5 hermanos en el mes de Septiembre del 2008. Está constituida por 40 empleados directos y 4 externos. Sus productos se comercializan en Zipaquirá, Cajicá, Chía, Funza, Mosquera, Madrid y en un sector de Bogotá. La empresa está en un proceso de crecimiento por lo tanto las ventas son realizadas por medio de distribuidores, realizando venta directa a pocos clientes, la empresa no cuenta con una estructura comercial, por lo que en los 6 años que lleva en el mercado su único instrumento para el crecimiento en ventas ha sido el voz a voz; con éste esquema se ha obtenido un leve crecimiento, sin embargo COLANDES requiere de un plan estratégico para mejorar su estructura creando un departamento comercial y fortaleciendo las demás áreas
Manihot-EcoMap - Distribución ecogeográfica del género Manihot en Colombia - Implicaciones para la conservación y flujo de genes entre cultivo silvestres
Physical activity through sustainable transport approaches (PASTA): protocol for a multi-centre, longitudinal study
BACKGROUND: Physical inactivity is one of the leading risk factors for non-communicable diseases, yet many are not sufficiently active. The Physical Activity through Sustainable Transport Approaches (PASTA) study aims to better understand active mobility (walking and cycling for transport solely or in combination with public transport) as an innovative approach to integrate physical activity into individuals' everyday lives. The PASTA study will collect data of multiple cities in a longitudinal cohort design to study correlates of active mobility, its effect on overall physical activity, crash risk and exposure to traffic-related air pollution.
METHODS/DESIGN: A set of online questionnaires incorporating gold standard approaches from the physical activity and transport fields have been developed, piloted and are now being deployed in a longitudinal study in seven European cities (Antwerp, Barcelona, London, Oerebro, Rome, Vienna, Zurich). In total, 14000 adults are being recruited (2000 in each city). A first questionnaire collects baseline information; follow-up questionnaires sent every 13 days collect prospective data on travel behaviour, levels of physical activity and traffic safety incidents. Self-reported data will be validated with objective data in subsamples using conventional and novel methods. Accelerometers, GPS and tracking apps record routes and activity. Air pollution and physical activity are measured to study their combined effects on health biomarkers. Exposure-adjusted crash risks will be calculated for active modes, and crash location audits are performed to study the role of the built environment. Ethics committees in all seven cities have given independent approval for the study.
DISCUSSION: The PASTA study collects a wealth of subjective and objective data on active mobility and physical activity. This will allow the investigation of numerous correlates of active mobility and physical activity using a data set that advances previous efforts in its richness, geographical coverage and comprehensiveness. Results will inform new health impact assessment models and support efforts to promote and facilitate active mobility in cities
Epstein Barr Virus-positive large T-cell lymphoma presenting as acute appendicitis 17 years after cadaveric renal transplant: a case report
<p>Abstract</p> <p>Introduction</p> <p>The majority of post-transplant lymphoproliferative disorders in renal transplant patients are of the B-cell phenotype, while the T-cell phenotype is rare. We report a case of Epstein Barr Virus-positive, T-cell lymphoma in a renal transplant patient, presenting unusually as acute appendicitis.</p> <p>Case presentation</p> <p>A 45-year-old Hispanic male renal transplant patient presented with right-side abdominal pain 17 years after transplant. The laboratory studies were unremarkable. Laparoscopic exploration showed an inflamed appendix so a laparoscopic appendectomy was performed. Pathology of the appendix showed large cells positive for CD3, CD56 and Epstein Barr Virus-encoded RNA staining, and negative for CD20 and CD30. The tissue tested positive for T-cell receptor gene rearrangement by polymerase chain reaction analysis. Treatment management involved reduction of immunosuppression and initiation of chemotherapy with cisplatin, etoposide, gemcitabine, and solumedrol followed by cyclophosphamide, hydroxydaunorubicin, vincristine and prednisone). He recovered and the allo-grafted kidney is fully functional.</p> <p>Conclusion</p> <p>We report a rare case of post-renal transplant large T-cell lymphoma, with an unusual presentation of acute appendicitis and Epstein Barr Virus-positivity, which responded well to chemotherapy.</p
Centrality categorization for R_{p(d)+A} in high-energy collisions
High-energy proton- and deuteron-nucleus collisions provide an excellent tool
for studying a wide array of physics effects, including modifications of parton
distribution functions in nuclei, gluon saturation, and color neutralization
and hadronization in a nuclear environment, among others. All of these effects
are expected to have a significant dependence on the size of the nuclear target
and the impact parameter of the collision, also known as the collision
centrality. In this article, we detail a method for determining centrality
classes in p(d)+A collisions via cuts on the multiplicity at backward rapidity
(i.e., the nucleus-going direction) and for determining systematic
uncertainties in this procedure. For d+Au collisions at sqrt(s_NN) = 200 GeV we
find that the connection to geometry is confirmed by measuring the fraction of
events in which a neutron from the deuteron does not interact with the nucleus.
As an application, we consider the nuclear modification factors R_{p(d)+A}, for
which there is a potential bias in the measured centrality dependent yields due
to auto-correlations between the process of interest and the backward rapidity
multiplicity. We determine the bias correction factor within this framework.
This method is further tested using the HIJING Monte Carlo generator. We find
that for d+Au collisions at sqrt(s_NN)=200 GeV, these bias corrections are
small and vary by less than 5% (10%) up to p_T = 10 (20) GeV. In contrast, for
p+Pb collisions at sqrt(s_NN) = 5.02 TeV we find these bias factors are an
order of magnitude larger and strongly p_T dependent, likely due to the larger
effect of multi-parton interactions.Comment: 375 authors, 18 pages, 16 figures, 4 tables. Submitted to Phys. Rev.
C. Plain text data tables for the points plotted in figures for this and
previous PHENIX publications are (or will be) publicly available at
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