Search results for "Environmental engineering"
showing 10 items of 2674 documents
2018
Abstract. In situ cloud observations at mountain-top research stations regularly measure ice crystal number concentrations (ICNCs) orders of magnitudes higher than expected from measurements of ice nucleating particle (INP) concentrations. Thus, several studies suggest that mountain-top in situ cloud microphysical measurements are influenced by surface processes, e.g., blowing snow, hoar frost or riming on snow-covered trees, rocks and the snow surface. This limits the relevance of such measurements for the study of microphysical properties and processes in free-floating clouds. This study assesses the impact of surface processes on in situ cloud observations at the Sonnblick Observatory in…
Parametric Design of Sailing Hull Shapes
2006
The author presents an original algorithm aimed at automatically generating the hull shape of a sailing yacht starting from an initial set of parameters. The procedure consists of two steps. First one keel line and a Designed Water Line (DWL in the following) are faired according to a set of parameters, say length of water line, canoe body draft, stem angle and some adimensional coefficients. This information is then used to fair the hull surface, which must in turn fulfil more prerequisites (parameters like displaty cement, floatation area and related coefficients). The hull is defined by means of a B-spline surface, the fairing of which is ensured by allowing for all the imposed objective…
Deducing a Drain Spacing Formula by Applying Dimensional Analysis and Self-Similarity Theory
2016
For designing a steady state drainage system a drain flow formula coupled with the Dupuit-Forcheimer form of the differential equation of groundwater flow is used. At first, in this paper the most applied drain flow formulas in steady-state conditions are reviewed and compared using as dependent variable the ratio between the maximum water table height and the distance between two lines of parallel drains. These equation are also tested using experimental field data measured in three plot drained by surface pipe drains having different value of drain spacing. Then, applying the dimensional analysis and the self-similarity theory, a new drain spacing formula is theoretically deduced and comp…
Modeling of PAH elimination by adiabatic steam stripping and intraparticle desorption
2003
The decontamination process of solids loaded with PAH in a pilot plant is modeled. This process is separated into two main stages: fast steam stripping at the entrance of the separation tube and the subsequent slow desorption of PAH from the interior of the soil particles. The stripping process also occurs in two stages: fast diffusion controlled saturation of the partial pressures followed by the heat transfer controlled evaporation. The phase diagram of PAH/water is constructed using both the microscopic model and empirical relationships for systems with wide miscibility gaps. The numerical basis for the calculations describing desorption from the soil particles is discussed. The model fo…
Comparison of laboratory-scale thermophilic biofilm and activated sludge processes integrated with a mesophilic activated sludge process
2003
A combined thermophilic-mesophilic wastewater treatment was studied using a laboratory-scale thermophilic activated sludge process (ASP) followed by mesophilic ASP or a thermophilic suspended carrier biofilm process (SCBP) followed by mesophilic ASP, both systems treating diluted molasses (dilution factor 1:500 corresponding GF/A-filtered COD (COD(filt)) of 1900+/-190 mgl(-1)). With hydraulic retention times (HRTs) of 12-18 h the thermophilic ASP and thermophilic SCBP removed 60+/-13% and 62+/-7% of COD(filt), respectively, with HRT of 8 h the removals were 48+/-1% and 69+/-4%. The sludge volume index (SVI) was notably lower in the thermophilic SCBP (measured from suspended sludge) than in …
Forest resources and sustainable tourism, a combination for the resilience of the landscape and development of mountain areas.
2020
The development of sustainable tourism models has been widely discussed in the economic literature. If on the one hand the demand for tourism has grown in recent years, on the other it is necessary to have adequate planning and political tools. The problems of sustainable tourism appear more complex when sustainable tourism involves development opportunities that require the support of the local community and the management of natural resources which are generally common goods. In these circumstances, new management structures need to be created, which can both meet the needs of the local community and ensure adequate management of natural resources. This study analyzes the connections betw…
STRATEGIC MANAGEMENT OF SUSTAINABLE DEVELOPMENT IN THE COUNTRYSIDE OF SIBIU DEPRESSION - BASIC OF ENVIRONMENTAL PROTECTION
2016
Integrated approach to the assessment of waste management systems within the SEA framework
2007
This paper addresses the problem of evaluating the environmental performances of Urban Waste Systems. Specifically, the paper refers to the crucial problem of environmentally analysing the Urban Waste System Management Process. The application of the Dashboard of Sustainability has been deliberately suggested. The method has been selected because of its intrinsic simplicity and because it can provide the simultaneous evaluation of indicators which refer to different fields, such as the Environment, Economics and Quality in Institutional Services. The method has been applied to the city of Palermo. The results obtained have been compared to a couple of ideal scenarios.
Survey-based qualitative analysis of young generation perception of sustainable development in Poland
2020
Abstract Understanding the perception of Sustainable Development can help to identify misconceptions surrounding the concept in order to design better education plans and public policies on this subject. Evaluating the perception of sustainability issues by focusing on the young generation as is an important proxy to imagine what the future holds for in terms of addressing sustainable development. We conducted 177 in-person interviews on a heterogeneous group of students and random volunteers in four cities in Poland to assess their perception of Sustainable Development. The vast majority (89.3%) of the respondents were familiar with the term ‘Sustainable Development’. However, part of them…
Coupling sustainable energy with membrane distillation processes for seawater desalination
2010
Desalination technologies nowadays is a very interesting and emerging alternative to conventional water sources; their high energy consumption, however, generates some problems in adopting them, especially in remote areas where electric grid is not available and fuel transportation is not always sustainable. In this paper a short overview of possible couplings between the membrane distillation technology for desalination and the use of sustainable thermal energy sources is presented. Two case studies of ongoing research projects at Universita di Palermo are also presented.