Técnicas de Visión Computacional para determinar el estado fitosanitario en plantaciones de brócoli

The demand for broccoli has increased significantly in the last years due to the benefits of its consumption for human health. This poses new challenges for producers, who increasingly rely on technology to improve production processes, increase yields and thereby meet the current demand. One of the technology fields that has gained interest in crop production the use of Computer Vision models, which can provide support and assistance in food production. This paper proposes an algorithm based on color detection of broccoli, which, at the macro level can identify phytosanitary problems in broccoli plantations; and, at the micro level can be used to identify the product that is suitable for consumption. The algorithm uses open source tools such as OpenCV and Python, so that it can be developed at low cost with results similar or better than those obtained with commercial softwares.La demanda de brócoli se ha incrementado notablemente en las últimas décadas debido a los benefcios que el consumo de este producto ofrece para la salud humana. Esto plantea nuevos retos para los productores, quienes cada vez más se apoyan en la tecnología para mejorar sus procesos productivos, incrementar los rendimientos y con ello satisfacer la demanda actual. Uno de los campos de la tecnología que ha cobrado interés en la producción agrícola es la aplicación de modelos de Visión Computacional, la cual puede proporcionar soporte y asistencia en la producción de alimentos. En este trabajo se propone un algoritmo basado en la detección de color del brócoli, el cual, a nivel “macro”, sea capaz de identifcar problemas ftosanitarios en plantaciones de brócoli; y, a nivel “micro”, pueda ser empleada para identifcar el producto apto para la comercialización y el consumo. El desarrollo del algoritmo utiliza herramientas de software libre, como OpenCV y Python, lo cual refleja que estas herramientas pueden ser desarrolladas a bajo costo; y que sus resultados son similares o superiores a los obtenidos con softwares comerciales

Super-Resolution Imaging with Patchy Microspheres

The diffraction limit is a fundamental barrier in optical microscopy, which restricts the smallest resolvable feature size of a microscopic system. Microsphere-based microscopy has proven to be a promising tool for challenging the diffraction limit. Nevertheless, the microspheres have a low imaging contrast in air, which hinders the application of this technique. In this work, we demonstrate that this challenge can be effectively overcome by using partially Ag-plated microspheres. The deposited Ag film acts as an aperture stop that blocks a portion of the incident beam, forming a photonic hook and an oblique near-field illumination. Such a photonic hook significantly enhanced the imaging contrast of the system, as experimentally verified by imaging the Blu-ray disc surface and colloidal particle arrays

Kinked silicon nanowires: Superstructures by metal assisted chemical etching

We report on metal assisted chemical etching of Si for the synthesis of mechanically-stable, hybrid crystallographic orientation Si superstructures with high aspect ratio, above 200. This one-pot-type method sustains high etching rates and facilitates reproducible results. The protocol enables the control of the number, angle and location of kinks via successive etch-quench sequences. We analysed relevant Au mask catalyst features to systematically assess their impact on a wide spectrum of etched morphologies that can be easily attained and customized by fine tuning of the critical etching parameters. For instance, the designed kinked Si nanowires can be internalized in biological cells, without affecting their viability. An accessible numerical model is provided to explain the etch profiles and the physico-chemical events at the Si-Au-electrolyte interface and offers guidelines for the development of finite-element modeling of metal assisted Si chemical etching

Wearable nano-engineered systems : towards real-time health monitoring for remote places

In the coming years preventive medicine and medical treatment will strongly rely on wearable and implantable biomedical devices. Advances in manufacturing, energy harvesting systems, and information technologies are contributing to a transformation in the mobile health era in terms of healthcare management and real-time, personalised tracking of the health status. Thus, the demand of wearable devices for monitoring and treatment of chronic diseases such as diabetes in remote places is expected to drastically increase. Specifically, the design and development of next-generation wearable devices for the diabetes treatment involves multi-disciplinary fields such as transdermal drug delivery, radio-frequency energy harvesting, and embedded, low-power electronics. In this thesis, we present the integration of various concepts from these areas relevant for wearable healthcare technologies to progress towards wearable devices for monitoring and treatment of diabetic patients in remote places. First, our efforts have been focused on the design, simulation, and fabrication of planar, small and flexible antennas for both radio-frequency energy harvesting and wireless communication purposes, focusing on the unlicensed band of 2.45 GHz. Next, a novel painless patch design is presented as a transdermal insulin delivery system. The patch is based on the integration of nano-engineered heating elements - gold nanomesh thin layers - on polyimide substrates for transdermal insulin therapy by wireless, electrothermal actuation. A thin film of reduced graphene oxide integrated onto the nanoheater provides the drug reservoir. Numerical computations to analyse the Joule heating of the patch in contact with the human skin were performed. Finally, the architecture and the design of the wearable electronic system to control the electrothermal patch with a smart phone are described, considering that the transdermal patch is powered via batteries and radio-frequency energy harvesting.(FSA - Sciences de l'ingénieur) -- UCL, 202

Flexible SiNWs-based thermoelectric generators for healthcare monitoring

Wearable devices for healthcare monitoring applications need reliable and miniaturized electrical power supplies. Human skin, involved in the regulation of the body temperature, can be exploited to harvest thermal energy in order to enable smart power sources. Converting heat into electricity requires a highly efficient thermoelectric generator (TEG) to facilitate adequate intake of the human skin thermal signature. For this purpose, silicon nanowires (SiNWs) have emerged as a promising material since nanofabrication allowed Si onedimensional nanostructures to achieve good thermoelectric properties such as: high Seebeck coefficient, high electrical conductivity, and low thermal conductivity. A high thermal to electrical conversion efficiency can be achieved with SiNWs-based TEGs. Such TEGs require a thermoelectric couple based on n-type and p-type SiNWs that exploits the Seebeck effect. Here, we report on different techniques to improve the dimensionless figure of merit (zT) of SiNWs. For instance, zT can be altered by blending SiNWs with a polymer, for example, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate), thus, lowering thermal conductivity. Measurements are sustained by numerical modeling and discussed within a general theoretical framework for SiNWs. Specifically, an array of SiNWs-based TEGs, interconnected according to electrical power levels required by electro-thermal drug delivery patches, is integrated on a human-skin compatible platform using polyethylene terephthalate as a substrate

Impedance sensing of polystyrene microspheres in a microfluidic channel: An integrated electrooptic method

Electrical impedance measurements through microfluidic channels have been extensively studied over the last years, because electrical impedance is a simple and essentially a noninvasive technique that allows characterization of nano- and microparticles or other inorganic nano- and microstructuresin a dielectric medium. Electrical impedance sensing has successfully been used in flow cell cytometry, allowing the classification of different cell types. Here are presented results for polystyrene microspheres in a custom electrical impedance system composed of a modified commercial microfluidic channel along with optical micro-imaging characterization in an inverted microscope, quantifying the relationship between microspheres density, wavelength illumination range and magnitude of the electrical impedance signal for carboxyl and amino functionalized-microspheres in different fluid media. These observations are sustained by numerical modeling and discussed within a general theoretical framework. The obtained results might have potential application to classify novel nano- and micro-objects and further develop artificial intelligence-enabled drug delivery platforms

Algoritmo para corregir la posición de matrices de datos (2D)

Las Matrices de Datos o códigos 2D, son ampliamente empleados en los diferentes sectores de la industria, generalmente para identificación y etiquetado. En el presente trabajo se aborda el problema del código 2D, cuando este no se encuentra debidamente en una posición vertical con respecto al dispositivo lector, esto puede ocasionar una demora en la lectura o incluso, el no reconocimiento del código por parte del dispositivo lector; por este motivo se plantea un algoritmo para corregir la posición del Datamatrix, basado en técnicas del procesamiento digital de imágenes, con las cuales se determinar el ángulo de desviación con respecto a la vertical, para su posterior rotación y corrección, la determinación del valor del ángulo es independiente de la orientación que tiene el código, que puede ser hacia la izquierda o hacia la derecha. Las herramientas de software libre y gratuitas OpenCV y Python permiten el desarrollo del algoritmo de una forma rápida y económica. Finalmente, las pruebas del algoritmo con datos reales, muestra buenos resultados

Tailoring zigzag and kinked silicon nanowires with metal assisted chemical etching

n/

Operación de pre-cocción del pescado y su incidencia en la calidad y el rendimiento del producto

El rendimiento del atún como materia prima en las empresas atuneras es una variable clave para la sostenibilidad económica de estas, por lo tanto, se realiza un estudio sobre los posibles factores que podrían condicionar los resultados durante el proceso productivo. Estos factores corresponden a variables cuantitativas como cualitativas que serán evaluadas en torno a las operaciones de pre-cocción y limpieza del pescado. El estudio se realiza de acuerdo a la estrategia de experimentación del diseño factorial de 23, y concluye con la modelación de las condiciones de operación a través de la regresión lineal múltiple y la metodología de superficie de respuesta

Electrothermal patches driving the transdermal delivery of insulin

Transdermal patches have become a widely used approach for painless delivery of drugs. One major current limitation of these systems remains the restricted skin permeation of proteins and peptides as exemplified by insulin, necessitating different considerations for their successful transdermal delivery. We present a novel patch design based on the integration of nano-engineered heating elements on polyimide substrates for electrothermal transdermal therapy. The results reveal that tuning of the electrical resistivity of an array of gold nanoholes, patterned on polyimide, facilitates a fast-responding electrothermal skin patch, while post-coating with reduced graphene oxide offers capabilities for drug encapsulation, like insulin. Application of insulin-loaded patches to the skin of mice resulted in blood glucose regulation within minutes. While demonstrated for insulin, the skin patches might be well adapted to other low and high molecular weight therapeutic drugs, enabling on-demand electrothermal transdermal delivery