Search results for "Cost analysis"
showing 10 items of 86 documents
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.
The contingent equilibrium during imbalanced volcano tourism demand through fee estimation: An empirical analysis of tourism in Mt. Etna
2022
Volcanic sites can be considered strategic areas for conservation and protection policies, but such policies may involve considerable costs However, not only are volcanic sites often integral to the tourism industry and, hence, of potential significant benefit to local economies in general; entrance fee income from tourists can also contribute to management and conservation costs in particular. Nevertheless, seasonal variations in tourism demand, resulting in over-and under-tourism situations, may impact on both the level of income generated as well as on the sustainability of sites Therefore, based on a case study of Mt Etna in Italy, this study considers establishing appropriate entry fee…
Estimating the environmental and resource costs of leakage in water distribution systems: A shadow price approach.
2016
Water scarcity is one of the main problems faced by many regions in the XXIst century. In this context, the need to reduce leakages from water distribution systems has gained almost universal acceptance. The concept of sustainable economic level of leakage (SELL) has been proposed to internalize the environmental and resource costs within economic level of leakage calculations. However, because these costs are not set by the market, they have not often been calculated. In this paper, the directional-distance function was used to estimate the shadow price of leakages as a proxy of their environmental and resource costs. This is a pioneering approach to the economic valuation of leakage exter…
Configurable low-cost plotter device for fabrication of multi-color sub-cellular scale microarrays.
2014
We report on the construction and operation of a low-cost plotter for fabrication of microarrays for multiplexed single-cell analyses. The printing head consists of polymeric pyramidal pens mounted on a rotation stage installed on an aluminium frame. This construction enables printing of microarrays onto glass substrates mounted on a tilt stage, controlled by a Lab-View operated user interface. The plotter can be assembled by typical academic workshops from components of less than 15 000 Euro. The functionality of the instrument is demonstrated by printing DNA microarrays on the area of 0.5 squared centimeters using up to three different oligonucleotides. Typical feature sizes are 5 μm diam…
Hot Impression Die Forging Process: An Approach to Flash Design for Tool Life Improvement
2005
In impression die forging the role of the flash geometry is fundamental since a proper design of the flash land strongly influences both the complete die filling and the die wear (i.e. the die life and the related costs). In this paper an integrated approach between numerical simulations and statistical tools was developed with the aim to optimize flash thickness in order to reduce die wear and to minimize material wasting. As wear is regarded, an analytical model depending on sliding velocity, temperature, die hardness and contact pressure was utilized during the numerical simulations of the process in order to reach a wear evaluation for different values of the flash design variables. Thu…
Effectiveness of a physical therapeutic exercise programme for caregivers of dependent patients: a pragmatic randomised controlled trial from Spanish…
2020
Producción Científica
Machine learning for energy cost modelling in wastewater treatment plants.
2018
Understanding the energy cost structure of wastewater treatment plants is a relevant topic for plant managers due to the high energy costs and significant saving potentials. Currently, energy cost models are generally generated using logarithmic, exponential or linear functions that could produce not accurate results when the relationship between variables is highly complex and non-linear. In order to overcome this issue, this paper proposes a new methodology based on machine-learning algorithms that perform better with complex datasets. In this paper, machine learning was used to generate high-performing energy cost models for wastewater treatment plants, using a database of 317 wastewater…
Long-term resource utilisation and associated costs of exercise during (neo)adjuvant oncological treatment: the Phys-Can project
2022
Background Exercise during oncological treatment is beneficial to patient health and can counteract the side effects of treatment. Knowledge of the societal costs associated with an exercise intervention, however, is limited. The aims of the present study were to evaluate the long-term resource utilisation and societal costs of an exercise intervention conducted during (neo)adjuvant oncological treatment in a randomised control trial (RCT) versus usual care (UC), and to compare high-intensity (HI) versus low-to-moderate intensity (LMI) exercise in the RCT. Methods We used data from the Physical Training and Cancer (Phys-Can) project. In the RCT, 577 participants were randomised to HI or to …
Economic and environmental sustainability of an AnMBR treating urban wastewater and organic fraction of municipal solid waste
2016
[EN] The objective of this study was to evaluate the economic and environmental sustainability of a sub- merged anaerobic membrane bioreactor (AnMBR) treating urban wastewater (UWW) and organic fraction of municipal solid waste (OFMSW) at ambient temperature in mild/hot climates. To this aim, power requirements, energy recovery from methane (biogas methane and methane dissolved in the effluent), consumption of reagents for membrane cleaning, and sludge handling (polyelectrolyte and energy consumption) and disposal (farmland, landfilling and incineration) were evaluated within different operating scenarios. Results showed that, for the operating conditions considered in this study, AnMBR tec…
Issues and Perspectives in the Application of Different Pavement Design Methods to Life Cycle Cost Analysis
2016
Life cycle costs analysis (LCCA) is an economic evaluation tool that can provide valuable guidance to transportation officials in management decision process. The application of LCCA to pavement management is vital because it permits the selection of the best alternative, based on the analysis of agency costs and user costs, taking into account (after selecting pavement type) different maintenance and rehabilitation (M&R) strategies within the same pavement type. Additionally, environmental costs can be considered. Issues arise when comparing the expected life of the pavement derived according to different pavement design tools, such as the Mechanistic-Empirical pavement Design Guide (M…