Search results for "VOLUME"
showing 10 items of 1932 documents
U.I.R.D.A. – Unbuilt Italian Rationalism Digital Archive
2018
For twenty years, the architecture of Italian rationalism through the digital modelling has been investigated. Very often, the production of a model and the consequent representation of tridimensional views, in many case studies, as outcome of the research on architecture have been considered. Actually, the digital model, intended as a critical tool, has to be conceived as a ‘starting point' for graphic analysis of architecture and not as the outcome. Indeed, it is associated to other graphics, sometimes not ‘deducted' from the model, useful for the understanding/translation of architecture. The construction of the model is not the construction of a simple image, operation, which is often c…
Once t hrough m ultistage fl ash d esalination: gPROMS d ynamic and s teady s tate m odeling
2010
This study focuses on modeling the steady state and dynamic behavior of the multistage flash desalination process (MSF) using gPROMS. This modeling tool allows for simultaneous coding of the system dynamics and steady state performance. In addition, it allows the use of the most efficient solvers for a set of non-linear differential and algebraic equations describing the MSF process. The system model and analysis are based on actual plant data that includes 21 flashing stages and a capacity of 378 kg/s (32,000 m3/d). The simulated unit is part of a massive MSF installation in Doha, Kuwait. System's dynamic behavior is simulated by a step change in the input values of the main operating para…
Description and commissioning of NEXT-MM prototype: first results from operation in a Xenon-Trimethylamine gas mixture
2014
[EN] A technical description of NEXT-MM and its commissioning and first performance is reported. Having an active volume of ∼35 cm drift × 28 cm diameter, it constitutes the largest Micromegas-read TPC operated in Xenon ever constructed, made by a sectorial arrangement of the 4 largest single wafers manufactured with the Microbulk technique to date. It is equipped with a suitably pixelized readout and with a sufficiently large sensitive volume (∼23 l) so as to contain long (∼20 cm) electron tracks. First results obtained at 1 bar for Xenon and Trymethylamine (Xe-(2%)TMA) mixture are presented. The TPC can accurately reconstruct extended background tracks. An encouraging fu…
Bubble formation at variously inclined nozzles
2014
Bubble formation at variously inclined submerged nozzles, fed with a continuous gas flow rate, is investigated. Results confirm previous findings, such as a substantial independence of bubble size of nozzle diameter and its dependence on the cubic root of gas flow rate at sufficiently high values of this parameter. Nozzle inclination in the range between 0 and 135° from the vertical upward orientation is found to have a negligible effect on bubble size. Observed bubble rise velocities lead to an estimation of the average liquid velocity induced by bubbles motion, leading in turn to a very simple correlation for the estimation of the liquid velocities induced by the repeated passage of bubbl…
Control of activated sludge settleability using preaeration and preprecipitation
1993
This paper deals with the addition of a preaeration and a preprecipitation stage to a conventional activated sludge process. The experiments were carried out in a pilot plant using wastewater from the city of Valencia (Spain) as feed. The effect of the F/M ratio and sludge age on sludge settleability was established. In both cases, process stability was observed to increase with respect to the conventional process. Good sludge settleability was thus assured in a greater F/M ratio range. A comparative economic study was also carried out.
Performance evaluation of a biotrickling filter treating a mixture of oxygenated VOCs during intermittent loading
2008
Laboratory scale-studies on the biodegradation of a 1:1:1 weight mixture of three oxygenated volatile organic compounds (VOCs), ethanol, ethyl acetate, and methyl-ethyl ketone (MEK) in a biotrickling filter (BTF) were carried out using two identically sized columns, filled with different polypropylene rings. The performance of the BTFs was examined for a period of 10 months applying several operational strategies. Similar performance was obtained for both supports. Intermittent flow rate of trickling liquid was shown beneficial to improve the removal efficiency (RE). Continuous feeding of VOC resulted in an excessive accumulation of biomass so high pressure drop was developed in less than 2…
Application of a new dynamic transport model to predict the evolution of performances throughout the nanofiltration of single salt solutions in conce…
2018
Although many knowledge models describing the rejection of ionic compounds by nanofiltration membranes are available in literature, they are all used in full recycling mode. Indeed, both permeate and retentate streams are recycled in order to maintain constant concentrations in the feed solution. However, nanofiltration of real effluents is implemented either in concentration or diafiltration modes, for which the permeate stream is collected. In these conditions, concentrations progressively evolve during filtration and classical models fail to predict performances. In this paper, an improvement of the so called "Donnan Steric Pore Model", which includes both volume and concentration variat…
Methane oxidation in a boreal climate in an experimental landfill cover composed from mechanically–biologically treated waste
2007
The present study evaluated microbial methane (CH4) oxidation in a boreally located outdoor landfill lysimeter (volume 112 m3, height 3.9 m) filled with mechanically-biologically treated waste (MBT residual) and containing a cover layer made from the same MBT residual. The calculations based on gas emission and pore gas measurements showed that, between April and October 2005, a significant proportion (96%) of the methane produced (23 l CH4 m(-2) d(-1)) in the lysimeter was oxidized. Methane was oxidized mainly at the depths of 35-75 cm, as indicated by the upward decrease both in the methane concentration and in the methane-to-carbon dioxide ratio in the pore gas. Lower methane oxidation (…
An integral approach to sludge handling in a WWTP operated for EBPR aiming phosphorus recovery: simulation of alternatives, LCA and LCC analyses
2020
[EN] As phosphorus is a non-renewable resource mainly used to produce fertilizers and helps to provide food all over the world, the proper management of its reserves is a global concern since it is expected to become scarcer in the near future. In this work we assessed two different sludge line configurations aiming for P extraction and recovery before anaerobic digestion and compared them with the classical configuration. This study has been performed by simulation with the model BNRM2 integrated in the software package DESASS 7.1. Configuration 1 was based on the production of a PO4-enriched stream from sludge via elutriation in the primary thickeners, while Configuration 2 was based on t…
Palliative Treatment of Dyspnea With Epidural Methadone in Advanced Emphysema
2005
This study investigated whether epidural methadone perfusion at the thoracic level can mitigate dyspnea in patients with advanced emphysema.Open-label clinical trial without a control group.University hospital.The inclusion criteria were a diagnosis of emphysema, basal dyspnea index (Mahler scale)or = 3, FEV(1)or = 35%, and no indication for pneumoreduction or lung transplantation surgery.An epidural catheter was inserted at the thoracic level connected to a perfusion pump for administering methadone (6 mg/24 h). Assessments were made at baseline, 1 week, and 1 month after catheter insertion.Pulmonary function tests were performed, and determinations were made of arterial blood gas levels, …