2,367 research outputs found

    Immobilization of arsenic from copper smelter waste

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    Arsenic is an inconvenient impurity for copper smelters and its problematic its bound to worsen as concentrates become dirtier. Air emissions are prevented during the off-gas treatment so it deports to liquid effluents and dusts. From effluents it cannot be removed easily together with other metals and specific removal needs to be considered. At industrial level the preferred choice is precipitation and copper smelters thus seek precipitates that are safe enough for inexpensive landfill disposal. The literature review identified the most common methods used by industry as well as more novel proposals to remove arsenic from solution. When precipitates or other types of solids are still too hazardous for safe disposal, it is possible to stabilise them with other methods discussed. The experimental work tested one solid stabilisation approach, vitrification, on hazardous copper smelter waste. Next, after producing an arsenic bearing solution similar to copper smelter effluents by leaching the same waste, five precipitation methods were tested: high iron arsenical ferrihydrite, a two-step process using aluminium and iron, arsenate hydroxyapatite, gypsum seeded scorodite and ferrous arsenate (symplesite). The short term leaching behaviour of the solids was tested with 24 hour bottle tests performed at different pH conditions. The results showed that all methods produced solids somewhat safer than the original one, but only the symplesite and two step precipitation methods have resulted in solids safe enough for landfill disposal. A preliminary cost estimation shows that these methods could be competitive with existing processes, while producing a safer solid. Regarding vitrification of the current waste, even though the particular conditions of the test were unable to produce a safe enough solid, the waste proved amenable to the process

    Identification and Characterization of the Lipid Transport System in the Tarantula Grammostola rosea

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    Lipids due to its hydrophobic nature are transported in the hemolymph mainly by lipoproteic fractions. In the present work we studied the lipoproteic fractions present in the hemolymph of the spider Grammostola rosea. Through ultracentrifugation two lipoproteic fractions are isolated, one of high density named Gr-HDL (δ = 1.13 - 1.15 g/ml) and the other of very high density called Gr-VHDL (δ = 1.24 - 1.27 g/ml) Gr-VHDL in hemolymph is majority in relation to Gr-HDL. In this sense Gr-VHDL fraction has 98.6% of hemolymphatic proteins, and 89.3% of lipids presents in the hemolymph. Both lipoproteic fractions possess phospholipids such as majority lipids (phosphatidylcholine and phosphatidylethanolamine) and 18:1, 16:0, 18:2 and 18:0 as the major fatty acids. In order to confirm the role played by lipoproteic fractions in vitro assays with different 14C-lipid were performed. It was observed that Gr-VHDL takes up mainly free fatty acids and triacylglycerols unlike that observed for Gr-HDL in relation to phosphatidylcholine. Through electrophoresis it was observed that Gr-VHDL has three proteins: a predominant band of 68 kDa and two others of 99 and 121 kDa. Gr-HDL displayed a predominant band of 93 kDa, and other minority of 249 kDa. In conclusion, this study reports lipid characterization of the lipoproteic fractions present in the hemolymph of the tarantula, G. rosea. The role of each lipoproteic fraction in relation to lipid up- take is sustained by in vitro assays. Similarities and differences are found when it is compared to lipoproteins of only the three species of spiders studied.Fil: Laino, Aldana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Cunningham, Monica Liliana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Suarez, Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Garcia, Carlos Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; Argentin

    PFS: A Productivity Forecasting System For Desktop Computers To Improve Grid Applications Performance In Enterprise Desktop Grid

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    An Enterprise Desktop Grid (EDG) is a low cost platform that gathers desktop computers spread over different institutions. This platform uses desktop computers idle time to run Grid applications. We argue that computers in these environments have a predictable productivity that affects a Grid application execution time. In this paper, we propose a system called PFS for computer productivity forecasting that improves Grid applications performance. We simulated 157.500 applications and compared the performance achieved by our proposal against two recent strategies. Our experiments show that a Grid scheduler based on PFS runs applications faster than schedulers based on other selection strategies.Fil: Salinas, Sergio Ariel. Universidad Nacional de Cuyo; ArgentinaFil: Garcia Garino, Carlos Gabriel. Universidad Nacional de Cuyo; ArgentinaFil: Zunino Suarez, Alejandro Octavio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tandil. Instituto Superior de Ingenieria del Software; Argentin

    ICE: Enabling Non-Experts to Build Models Interactively for Large-Scale Lopsided Problems

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    Quick interaction between a human teacher and a learning machine presents numerous benefits and challenges when working with web-scale data. The human teacher guides the machine towards accomplishing the task of interest. The learning machine leverages big data to find examples that maximize the training value of its interaction with the teacher. When the teacher is restricted to labeling examples selected by the machine, this problem is an instance of active learning. When the teacher can provide additional information to the machine (e.g., suggestions on what examples or predictive features should be used) as the learning task progresses, then the problem becomes one of interactive learning. To accommodate the two-way communication channel needed for efficient interactive learning, the teacher and the machine need an environment that supports an interaction language. The machine can access, process, and summarize more examples than the teacher can see in a lifetime. Based on the machine's output, the teacher can revise the definition of the task or make it more precise. Both the teacher and the machine continuously learn and benefit from the interaction. We have built a platform to (1) produce valuable and deployable models and (2) support research on both the machine learning and user interface challenges of the interactive learning problem. The platform relies on a dedicated, low-latency, distributed, in-memory architecture that allows us to construct web-scale learning machines with quick interaction speed. The purpose of this paper is to describe this architecture and demonstrate how it supports our research efforts. Preliminary results are presented as illustrations of the architecture but are not the primary focus of the paper

    Aportación metodológica para determinar el índice de calidad del medio ambiente urbano y edificado del Área Metropolitana de Barcelona

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    El presente trabajo está orientado hacia la determinación de una metodología que evalúa características socio-residenciales, diagnostica el estado de bienestar del medio ambiente urbano del Área Metropolitana de Barcelona (AMB), responde al estado en que se encuentran las viviendas pre-existentes al 2001. La investigación incorpora una aportación al enfoque de valoración inmobiliaria sustentada en técnicas de valores sociales como parte de un contexto integral. La orientación al desarrollo sostenible constituye dar un enfoque de valoración inmobiliaria, es decir, retomando el valor de uso como una combinación de valores urbanos y de satisfacción residencial en la base del análisis. La hipótesis de la investigación nace a partir de desarrollar una metodología sustentada en indicadores parciales (simples) idóneos para la obtención del Índice de Calidad Edificada del AMB obtenido por el método del indicador sintético de distancia DP2. El objetivo de la investigación es demostrar la validación del método del indicador sintético de distancia.This work is oriented towards the determination of a methodology to assess socio-residential characteristics, diagnoses the welfare state of the urban environment in the metropolitan area of Barcelona (AMB), responds to the state that are pre-existing dwellings to 2001 . The research incorporates a contribution to real estate valuation approach supported by techniques of social values as part of a comprehensive context. The sustainable development orientation is an approach to property valuation, returning the value in use as a combination of urban values and residential satisfaction in the analysis. The hypothesis of the research stems from developing a methodology supported by partial indicators (simple) suitable for obtaining Built Quality Index of AMB obtained by the method of the synthetic indicator DP2 away. The objective of this research is to demonstrate the validation of the method of the synthetic indicator away.Peer Reviewe

    Design of a Segmentation and Classification System for Seed Detection Based on Pixel Intensity Thresholds and Convolutional Neural Networks

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    Due to the computational power and memory of modern computers, computer vision techniques and neural networks can be used to develop a visual inspection system of agricultural products to satisfy product quality requirements. This chapter employs artificial vision techniques to classify seeds in RGB images. As a first step, an algorithm based on pixel intensity threshold is developed to detect and classify a set of different seed types, such as rice, beans, and lentils. Then, the information inferred by this algorithm is exploited to develop a neural network model, which successfully achieves learning classification and detection tasks through a semantic-segmentation scheme. The applicability and satisfactory performance of the proposed algorithms are illustrated by testing with real images, achieving an average accuracy of 92% in the selected set of classes. The experimental results verify that both algorithms can directly detect and classify the proposed set of seeds in input RGB images. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG

    Gestión para la infraestructura it mediante servicios dhcp server, dns server, controlador de dominio, proxy no transparente, file server y print server bajo zentyal server

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    Como solución a la solicitud de nuestro cliente, se desea implementar una infraestructura de los servicios tecnológicos; donde gestionaremos la instalación y configuración de Zentyal Server, esta herramienta es un sistema que se encuentra enlazado en una plataforma web, contando con varios servicios que permitirán la instalación de módulos para la ejecución, configuración y administración de servidores DHCP, DNS, Controles de dominio, Proxy transparente, File Server, Print Server entre otros. Permitiendo de esta manera llevar un dominio total de los recursos tecnológicos con los que cuenta el cliente, brindando una seguridad y buen manejo a las prácticas de las TIC.As a solution to the request of our client wants to implement a technological services infrastructure; where we will manage the installation and configuration of Zentyal Server, this tool is a system that is is linked on a web platform, counting with various services that will allow the installation of modules for execution, configuration and server management DHCP, DNS, Controls domain, Transparent Proxy, File Server, Print Server among others. Allowing in this way to carry a total control of technological resources with which customer account, providing security and good management of TIC practices

    A fatal case of Nocardia otitidiscaviarum pulmonary infection and brain abscess: taxonomic characterization by molecular techniques

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    We report on a rare case of pulmonary Nocardiosis and brain abscess caused by Nocardia otitidiscaviarum in an elderly woman with chronic obstructive pulmonary disease. Taxonomic identification involved phenotypic testing, restriction fragment length polymorphism (RFLP), and complete 16S rRNA gene sequencing

    CO2 Transoral Laser Microsurgery in Benign, Premalignant and Malignant (Tis, T1, T2) Lesion of the Glottis. A Literature Review

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    Carbon Dioxide transoral laser microsurgery represents a reliable option for the treatment of early glottic carcinoma (Tis-T2), with good functional and oncological outcomes, nowadays representing one of the main options in larynx preservation protocols. The development and improvement of laser devices means surgeons are able to use more precise instruments compared with classic cold dissection in laser-assisted phonosurgery. Secondary effects on voice, swallowing, or quality of life as well as complications have been well documented. Also, with the introduction of a new proposal for staging systems following the principle of the three-dimensional map of isoprognostic zones, the use of narrow-band imaging in clinical evaluation and intraoperative, and the implementation of diffusion-weighted magnetic resonance during preoperative evaluation, the development of new tools to improve surgical quality and preliminary reports regarding the use of carbon dioxide laser in transoral robotic surgery suggests an exciting future for this technique

    DEGRADACIÓN ANORMAL DE P53 E INDUCCIÓN DE APOPTOSIS EN LA RED P53-MDM2 USANDO LA ESTRATEGIA DE CONTROL TIPO PIN

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    Este artículo presenta el control tipo “PIN” para regular la actividad de la red p53-Mdm2. Esta red considera la degradación de p53 mediada por el incremento de Mdm2, el cual perturba la respuesta de estrés normal de p53. El modelo considera tres proteínas: p53, Mdm2 y ARF. p53 es regulado a través de un ciclo de retroalimentación que involucra su gen objetivo Mdm2 y un regulador indirecto ARF. Se presentan dos escenarios. Para el primer escenario, la red responde a un incremento de Mdm2 y una baja regulación de p53 sin ninguna entrada externa; luego, en el segundo escenario apoptosis es inducido por el control tipo “PIN”. El comportamiento dinámico de la red y la efectividad del controlador propuesto son ilustrados vía simulaciones
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