Search results for "Earth"
showing 10 items of 12204 documents
The role of extracellular polymeric substances on aerobic granulation with stepwise increase of salinity
2018
Abstract A granular sequencing batch reactor (GSBR) worked for 164 days to study the effect of salinity on aerobic granulation. The feeding had an organic loading rate (OLR) of 1.6 kg COD⋅m −3 ⋅d −1 and a gradual increase of salinity (from 0.30 to 38 g NaCl − ⋅L −1 ) to promote a biological salt-adaptation. First aggregates (average diameter ≈ 0.4 mm) appeared after 14 days. Extracellular polymeric substances (EPSs) analyses revealed that proteins were mainly higher than polysaccharides, and microorganisms metabolized EPSs as additional carbon source, mostly in feast phase, to face the energy demand for salinity adaptation. No significant worsening of organic matter removal was observed. Th…
Improvement of lateral connectivity in a sector of River Hârtibaciu (Olt/Danube Basin)
2017
Abstract The Hârtibaciu River in the Alţâna area has a disturbed lateral connectivity owing to its lateral embankments, as a result of which fish communities in this river sector are negatively influenced. The method of obtaining the water supply for a new proposed wetland is by gravitation, and any excessive water supply to the wetland will be controled and directed to the Hârtibaciu River in a natural manner. A state-of-the-art man-made wetland should increase the quality of the habitat for local fish communities, especially for the Rhodeus sericeus population, which is a species of conservation interest.
Analytical approach extending the Granier method to radial sap flow patterns
2020
Abstract The Granier thermal dissipation (TD) method is probably the most applied method to compute the transpiration flux of trees, due to its simplicity and effective compromise between theory and data availability. Starting from the heat transfer equations at the basis of Granier’s method, the objective of this paper is to derive an analytical solution for the transpiration flux to extend the sap flow equations to the radial domain. We adopted a flexible approach to cope with the differences in radial sapflow density (SFD) profile shapes that are known to occur in relation to wood anatomy (diffuse porous vs. ring- or non-porous xylem). With this purpose, we investigated the robustness of…
Analysis of uncontrolled phosphorus precipitation in anaerobic digesters under thermophilic and mesophilic conditions.
2019
This study compares the operation of mesophilic and thermophilic anaerobic digestion of sewage sludge and their effects in uncontrolled phosphorus precipitation. The research has been carried out using a pilot plant consisting of two digesters of 1.6 m3 working volume, treating the mixed sludge of Alzira WWTP (Valencia, Spain). The digesters were operated in parallel, at different conditions: mesophilic (38 ± 2.0°C) and thermophilic (55 ± 2.5°C) temperatures and organic loading rates (OLR) ranging from 1.1 to 1.7 kg volatile solids (VS) m−3 d−1 and different hydraulic retention times (HRT) 20, 15 and 12 days. Uncontrolled precipitation was evaluated through P, Mg and Ca mass balances in bot…
Análisis para la Implementación del Sistema de Gestión de Calidad y del Sistema de Gestión Ambiental para el Laboratorio de Análisis Instrumental de …
2019
El Laboratorio de Análisis Instrumental ubicado en el 5to piso del Edificio No. 17 de la Escuela Politécnica Nacional brinda servicios de análisis de gases de pozo, biogás, biocidas, solventes, vidrios laminados y templados, entre otros; no obstante, no cuenta con un sistema integrado de Gestión que incluya la ISO 9001:2015 ni ISO 14001:2015, los cuales deberían ser una base fundamental a fin de permitir una dirección basada en la optimización de procesos con una disminución de los impactos ambientales que puede generar cualquier empresa. Con estos antecedentes, el presente trabajo tiene por objetivo desarrollar un mecanismo para implementación de un SIG y que vaya acorde a la normativa ISO…
Traffic data acquirement by unmanned aerial vehicle
2017
This paper presents a methodology aimed to acquire traffic flow data through the employment of unmanned aerial vehicles (UAVs). The study is focused on the determination of driving behavior parameters of road users and on the reconstruction of traffic flow Origin/Destination matrix. The methodology integrates UAV flights with video image processing technique, and the capability of geographic information systems, to represent spatiotemporal phenomena. In particular, analyzing different intersections, the attention of the authors is focused on users’ gap acceptance in a naturalistic drivers’ behavior condition (drivers are not influenced by the presence of instruments and operators on the roa…
Geometrical deviation of end-of-life parts as a consequence of reshaping by single point incremental forming
2021
AbstractPutting in place circular economy strategies is an urgent challenge to face. In this scenario, manufacturing processes play a relevant role as efficient material reuse enabler. Scientists have to make an effort either to find new process or to rethink old process to reprocess end-of-life (EoL) component to recover both material and functions. In this paper, single point incremental forming (SPIF) process is used for reshaping sheet metal EoL components. The entire process chain was replicated including both deep drawing process (to imitate the end-of-life component) as well as SPIF operations (to obtain the reshaped components). The geometrical deviation as a consequence of SPIF ope…
Underwater Wireless Communications for Cooperative Robotics with UWSim-NET
2019
The increasing number of autonomous underwater vehicles (AUVs) cooperating in underwater operations has motivated the use of wireless communications. Their modeling can minimize the impact of their limited performance in real-time robotic interventions. However, robotic frameworks hardly ever consider the communications, and network simulators are not suitable for HIL experiments. In this work, the UWSim-NET is presented, an open source tool to simulate the impact of communications in underwater robotics. It gathers the benefits of NS3 in modeling communication networks with those of the underwater robot simulator (UWSim) and the robot operating system (ROS) in modeling robotic systems. Thi…
Using the Analytic Hierarchy Process (AHP) and fuzzy logic to evaluate the possibility of introducing single point incremental forming on industrial …
2018
Abstract Single point incremental forming (SPIF) is a promising forming process, yet not entirely accepted and implemented on industrial scale, due to several reasons, presented in the paper. The approach presented here develops an evaluation method for the degree of its industrial implementation. Several factors which will favor the industrial implementation of ASPIF are identified and their weights are hierarchized by means of AHP. To assess the robustness of the AHP, a sensitivity analysis was also presented. Furthermore, a fuzzy inference system was built, having as output the degree of industrial implementation of SPIF.
Using the Analytic Hierarchy Process (AHP) in Evaluating the Decision of Moving to a Manufacturing Process Based Upon Continuous 5 Axes CNC Machine-t…
2016
Abstract This paper represents the second part of the work described in the paper with the title “Decision-making tool for moving from 3-axes to 5-axes CNC machine-tool”. The problem of using either 3 axes CNC machine-tools or 5 axes CNC machine tools was presented in the first part, together with a fuzzy logic based decision support tool. This time, an AHP approach is used in order to evaluate the decision of moving to a manufacturing process based upon 5 axes machine tools. Three variants were taken into consideration and analysed. The consistency of the proposed approach was evaluated and a sensitivity analysis was also introduced.