29,582 research outputs found
Modelling of priority pollutants releases from urban areas
In the framework of the EU project ScorePP (Source Control Options for Reducing Emissions of Priority Pollutants), dynamic PPs (priority pollutants) fate models are being developed to assess appropriate strategies for limiting the release of PPs from urban sources and for treating PPs on a variety of spatial scales. Different possible sources of PP releases were mapped and both their release pattern and their loads were quantified as detailed as possible.
This paper focuses on the link between the gathered PP sources data and the dynamic models of the urban environment. This link consists of: (1) a method for the quantitative and structured storage of temporal emission pattern information, (2) the coupling of GIS-based spatial emission source data with temporal emission pattern information and (3) the generation of PP release time series to feed the dynamic sewer catchment model.
Steps 2 and 3 were included as the main features of a dedicated software tool. Finally, this paper also illustrates the methodâs applicability to generate model input timeseries for generic pollutants (N, P and COD/BOD) in addition to priority pollutants
Confirmation of the Dietary Background of Beef from its Stable Isotope Signature
End of project reportConsumers are increasingly demanding information on the authenticity and source of the food they purchase. Molecular DNA-based technology allows animal identification, but without certification or a âpaper-trailâ but does not provide information about feed history or the production system under which the animal was reared. The stable isotopes of chemical elements (e.g.13C/12C, 15N/14N) are naturally present in animal tissue and reflect the isotopic composition of the diet. The overall aim of this project was to determine the feasibility of using the stable isotopic composition as an intrinsic, biochemical marker to gain information about feed components used in the production of beef. Factors likely to affect the isotopic signature such as source of tissue, duration of feeding and production systems were examined. It is expected that this highly innovative and original technique will permit the identification of country of origin and dietary history of beef and so greatly assist efforts to market Irish beef, particularly in lucrative European markets. Sequential sampling and stable isotope analysis of bovine tail hair and hoof revealed that the two tissues can provide a detailed and continuous record of animal dietary history. Because hair can be sampled repeatedly and noninvasively, we anticipate that this approach will also prove useful for the investigation of short-term wildlife movements and changes in dietary preferences
A review of High Performance Computing foundations for scientists
The increase of existing computational capabilities has made simulation
emerge as a third discipline of Science, lying midway between experimental and
purely theoretical branches [1, 2]. Simulation enables the evaluation of
quantities which otherwise would not be accessible, helps to improve
experiments and provides new insights on systems which are analysed [3-6].
Knowing the fundamentals of computation can be very useful for scientists, for
it can help them to improve the performance of their theoretical models and
simulations. This review includes some technical essentials that can be useful
to this end, and it is devised as a complement for researchers whose education
is focused on scientific issues and not on technological respects. In this
document we attempt to discuss the fundamentals of High Performance Computing
(HPC) [7] in a way which is easy to understand without much previous
background. We sketch the way standard computers and supercomputers work, as
well as discuss distributed computing and discuss essential aspects to take
into account when running scientific calculations in computers.Comment: 33 page
A structured approach for the engineering of biochemical network models, illustrated for signalling pathways
http://dx.doi.org/10.1093/bib/bbn026Quantitative models of biochemical networks (signal transduction cascades, metabolic pathways, gene regulatory circuits) are a central component of modern systems biology. Building and managing these complex models is a major challenge that can benefit from the application of formal methods adopted from theoretical computing science. Here we provide a general introduction to the field of formal modelling, which emphasizes the intuitive biochemical basis of the modelling process, but is also accessible for an audience with a background in computing science and/or model engineering. We show how signal transduction cascades can be modelled in a modular fashion, using both a qualitative approach { Qualitative Petri nets, and quantitative approaches { Continuous Petri Nets and Ordinary Differential Equations. We review the major elementary building blocks of a cellular signalling model, discuss which critical design decisions have to be made during model building, and present ..
Special Libraries, October 1955
Volume 46, Issue 8https://scholarworks.sjsu.edu/sla_sl_1955/1007/thumbnail.jp
The effects of MgO, Na2O and SO3 on industrial clinkering process: phase composition, polymorphism, microstructure and hydration, using a multidisciplinary approach
Preprint publicado en: Materials Characterization Volume 155, September 2019, 109809The present investigation deals with how minor elements (their oxides: MgO, Na2O and SO3) in industrial kiln
feeds affect (i) chemical reactions upon clinkering, (ii) resulting phase composition and microstructure of
clinker, (iii) hydration process during cement production.
Our results show that all these points are remarkably sensitive to the combination and interference effects
between the minor chemical species mentioned above.
Upon clinkering, all the industrial raw meals here used exhibit the same formation temperature and amount
of liquid phase. Minor elements are preferentially hosted by secondary phases, such as periclase. Conversely, the
growth rate of the main clinker phases (alite and belite) is significantly affected by the nature and combination
of minor oxides. MgO and Na2O give a very fast C3S formation rate at T > 1450 K, whereas Na2O and SO3 boost
C2S
After heating, if SO3 occurs in combination with MgO and/or Na2O, it does not inihibit the C3S crystallisation
as expected. Rather, it promotes the stabilisation of M1-C3S, thus indirectly influencing the aluminate content,
too. MgO increseases the C3S amount and promotes the stabilisation of M3-C3S, when it is in combination with
Na2O. Na2O seems to be mainly hosted by calcium aluminate structure, but it does not induce the stabilisation of
the orhtorhombic polymorph, as supposed to occur. Such features play a key role in predicting the physicalmechanical
performance of a final cement (i.e. rate of hydration and hardening) when used as a bulding material.The present study has been partly funded by the project PRIN 2017
(2017L83S77), of the Italian Ministry for Education, University and
Research (MIUR)
Constructing a price deflator for R&D: calculating the price of knowledge investments as a residual
Working Pape
Designing algorithms to aid discovery by chemical robots
Recently, automated robotic systems have become very efficient, thanks to improved coupling between sensor systems and algorithms, of which the latter have been gaining significance thanks to the increase in computing power over the past few decades. However, intelligent automated chemistry platforms for discovery orientated tasks need to be able to cope with the unknown, which is a profoundly hard problem. In this Outlook, we describe how recent advances in the design and application of algorithms, coupled with the increased amount of chemical data available, and automation and control systems may allow more productive chemical research and the development of chemical robots able to target discovery. This is shown through examples of workflow and data processing with automation and control, and through the use of both well-used and cutting-edge algorithms illustrated using recent studies in chemistry. Finally, several algorithms are presented in relation to chemical robots and chemical intelligence for knowledge discovery
Tracking sources and fate of groundwater nitrate in Kisumu City and Kano Plains, Kenya
Groundwater nitrate (NO3â) pollution sources and in situ attenuation were investigated in Kisumu city and Kano plains. Samples from 62 groundwater wells consisting of shallow wells (hand dug, depth 15 m) were obtained during wet (MayâJuly 2017) and dry (February 2018) seasons and analyzed for physicochemical and isotopic (δ15N-NO3â, δ18O-NO3â, and δ11B) parameters. Groundwater NO3â concentrations ranged from <0.04 to 90.6 mg Lâ1. Boreholes in Ahero town showed significantly higher NO3â (20.0â70.0 mg Lâ1) than boreholes in the Kano plains (<10.0 mg Lâ1). Shallow wells in Kisumu gave significantly higher NO3â (11.4â90.6 mg Lâ1) than those in the Kano plains (<10.0 mg Lâ1). About 63% of the boreholes and 75% of the shallow wells exceeded the drinking water WHO threshold for NO3â and NO2â (nitrite) during the study period. Mean δ15N-NO3â values of 14.8â° Âą 7.0â° and 20.7â° Âą 11.1â°, and δ18O-NO3â values of 10.2â° Âą 5.2â° and 13.2â° Âą 6.0â° in wet and dry seasons, respectively, indicated manure and/or sewage as main sources of groundwater NO3â. However, a concurrent enrichment of δ15N and δ18O was observed, especially in the dry season, with a corresponding NO3â decrease, indicating in situ denitrification. In addition, partial nitrification of mostly sewage derived NH4+ appeared to be responsible for increased NO2â concentrations observed in the dry season. Specifically, targeted δ11B data indicated that sewage was the main source of groundwater NO3â pollution in shallow wells within Kisumu informal settlements, boreholes in Ahero, and public institutions in populated neighborhoods of Kano; while manure was the main source of NO3â in boreholes and shallow wells in the Kano and planned estates around Kisumu. Waste-water sanitation systems in the region should be urgently improved to avoid further deterioration of groundwater sources
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