213 research outputs found

    Proyecto de producción y exportación de dulce de membrillo a inmigrantes ecuatorianos que residen en la ciudad de nueva york, estados unidos

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    Project Production and Export of Sweet Quince aims to reach the market for Ecuadorian migrants residing in the New York City. The market strategy is to appeal to the sentiment of the Ecuadorian immigrants, who yearn to enjoy its typical products of Ecuador. Through market research, it was determined that there is a high degree of acceptance of the product. About 90% of respondents, who have already tried sweet quince, are willing to buy the product. 16% of people who consume traditional sweets Ecuadorians in New York City, they qualify sweet quince as your preference. Regarding the Technical Study emphasizes that the project does not require a large investment in terms of investment in equipment and physical works, which becomes attractive relative to the project. In the Financial Study two scenarios were developed, one with a debt of 40% debt and 60% equity and the other method under 100% of equity. In both cash flows the NPV is a positive value and the IRR is higher than TMAR, making the project profitable

    Ruddlesden–Popper hybrid lead bromide perovskite nanosheets of phase pure n=2: Stabilized colloids stored in the solid state

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    Ruddlesden-Popper lead halide perovskite (RP-LHP) nano-nanostructures can be regarded as self-assembled quantum wells or superlattices of 3D perovskites with an intrinsic quantum well thickness of a single or a few (n=2-4) lead halide layers; the quantum wells are separated by organic layers. They can be scaled down to a single quantum well dimension. Here, the preparation of highly (photo)chemical and colloidal stable hybrid LHP nanosheets (NSs) of ca. 7.4 µm lateral size and 2.5 nm quantum well height (thereby presenting a deep blue emission at ca. 440 nm), is reported for the first time. The NSs are close-lying and they even interconnect when deposited on a substrate. Their synthesis is based on the use of the p-toluenesulfonic acid/dodecylamine (pTS/DDA) ligand pair and their (photo)chemical stability and photoluminescence is enhanced by adding EuBr2 nanodots (EuNDs). Strikingly, they can be preserved as a solid and stored for at least one year. The blue emissive colloid can be recovered from the solid as needed by simply dispersing the powder in toluene and then using it to prepare solid films, making them very promising candidates for manufacturing devices. © 2021 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH

    DFTB+, a software package for efficient approximate density functional theory based atomistic simulations

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    DFTB+ is a versatile community developed open source software package offering fast and efficient methods for carrying out atomistic quantum mechanical simulations. By implementing various methods approximating density functional theory (DFT), such as the density functional based tight binding (DFTB) and the extended tight binding method, it enables simulations of large systems and long timescales with reasonable accuracy while being considerably faster for typical simulations than the respective ab initio methods. Based on the DFTB framework, it additionally offers approximated versions of various DFT extensions including hybrid functionals, time dependent formalism for treating excited systems, electron transport using non-equilibrium Green’s functions, and many more. DFTB+ can be used as a user-friendly standalone application in addition to being embedded into other software packages as a library or acting as a calculation-server accessed by socket communication. We give an overview of the recently developed capabilities of the DFTB+ code, demonstrating with a few use case examples, discuss the strengths and weaknesses of the various features, and also discuss on-going developments and possible future perspectives

    Evaluación de tres dosis de potasio en la producción de lechuga (Lactuca sativa L. var. Crispa) bajo el sistema hidropónico recirculante NTF bajo invernadero

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    Three doses of potassium were evaluated in the production of lettuce (Lactuca sativa L. var. Crispa), under the recirculable NFT hydroponic system in the greenhouse of the Department of Horticulture of the ESPOCH. A completely randomized block design was used with three treatments and three replications. The doses evaluated were: low dose (LD) with 224,33 ppm, medium dose (MD) with 470,00 ppm, and high dose (HD) with 716,67 ppm. Evaluated parameters were: potassium content in leaves and root, fresh weights of the aerial part and root, yield per net plot and hectare. The economic analysis was carried out according to the relation benefit/cost. The best results for most of the parameters evaluated were obtained with the low dose (LD), obtaining fresh weights of the aerial part and root of 193,01 and 36,65 g respectively. It has a yield per net plot of 2,04 kilograms and per hectare of 15338,75 kilograms, and the highest cost benefit with 4,63 dollars equivalent to 362,75%. On the other hand, the highest content of potassium in leaves and root up to 40 days after transplant (DAT) was obtained with the medium dose (MD) with 5,13 and 6,00% of total potassium, respectively. In all treatments, maintaining turgor in the plants throughout the cycle is very important. From the agronomic and economic point of view, the use a nutritive solution containing 224,33 ppm of potassium was recommended

    Data size increment for fault detection on rotating machinery

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    En los últimos años se ha incrementado el uso de técnicas de modelamiento basado en datos para el diagnóstico de fallos en maquinaria rotativa. Estas técnicas requieren de grandes cantidades de datos que no siempre se pueden obtener pues generan  altos costos y tiempo excesivo, que son difíciles de solventar desde el punto de vista económico y técnico.  El presente trabajo se enfoca en el pre-procesamiento de las señales de vibración y propone un método para incrementar el número de series temporales informativas de una máquina rotativa sin el incremento del tiempo y costos en la etapa de adquisición de las señales. Como resultado se ha obtenido una ampliación de 315 señales en la fase de adquisición de datos a 429000 luego de la aplicación del método; cantidad adecuada para la construcción de modelos basados en datos, incluso de deep learning para la detección de fallos en maquinaria rotativa. Palabras clave: Adquisición de datos, pre-procesamiento, rodamientos, señales.  

    DFTB+, a software package for efficient approximate density functional theory based atomistic simulations

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    DFTB+ is a versatile community developed open source software package offering fast and efficient methods for carrying out atomistic quantum mechanical simulations. By implementing various methods approximating density functional theory (DFT), such as the density functional based tight binding (DFTB) and the extended tight binding method, it enables simulations of large systems and long timescales with reasonable accuracy while being considerably faster for typical simulations than the respective ab initio methods. Based on the DFTB framework, it additionally offers approximated versions of various DFT extensions including hybrid functionals, time dependent formalism for treating excited systems, electron transport using non-equilibrium Green's functions, and many more. DFTB+ can be used as a user-friendly standalone application in addition to being embedded into other software packages as a library or acting as a calculation-server accessed by socket communication. We give an overview of the recently developed capabilities of the DFTB+ code, demonstrating with a few use case examples, discuss the strengths and weaknesses of the various features, and also discuss on-going developments and possible future perspectives

    Strengthening the Reporting of Observational Studies in Epidemiology-Nutritional Epidemiology (STROBE-nut): An Extension of the STROBE Statement.

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    Concerns have been raised about the quality of reporting in nutritional epidemiology. Research reporting guidelines such as the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement can improve quality of reporting in observational studies. Herein, we propose recommendations for reporting nutritional epidemiology and dietary assessment research by extending the STROBE statement into Strengthening the Reporting of Observational Studies in Epidemiology-Nutritional Epidemiology (STROBE-nut).Recommendations for the reporting of nutritional epidemiology and dietary assessment research were developed following a systematic and consultative process, coordinated by a multidisciplinary group of 21 experts. Consensus on reporting guidelines was reached through a three-round Delphi consultation process with 53 external experts. In total, 24 recommendations for nutritional epidemiology were added to the STROBE checklist.When used appropriately, reporting guidelines for nutritional epidemiology can contribute to improve reporting of observational studies with a focus on diet and health
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