895 research outputs found
The role of noise and initial conditions in the asymptotic solution of a bounded confidence, continuous-opinion model
We study a model for continuous-opinion dynamics under bounded confidence. In
particular, we analyze the importance of the initial distribution of opinions
in determining the asymptotic configuration. Thus, we sketch the structure of
attractors of the dynamical system, by means of the numerical computation of
the time evolution of the agents density. We show that, for a given bound of
confidence, a consensus can be encouraged or prevented by certain initial
conditions. Furthermore, a noisy perturbation is added to the system with the
purpose of modeling the free will of the agents. As a consequence, the
importance of the initial condition is partially replaced by that of the
statistical distribution of the noise. Nevertheless, we still find evidence of
the influence of the initial state upon the final configuration for a short
range of the bound of confidence parameter
Life cycle and environmental assessment of calcium looping (CaL) in solar thermochemical energy storage
Calcium looping is a promising thermochemical energy storage process to be integrated into concentrating solar power plants. This work develops for the first time a comprehensive life cycle assessment of the calcium looping integration in solar plants to assess the potential of the technology from an environmental perspective. Two representative integrations are analysed, representing daily (hot) and seasonal (cold) storage designs. Similar performance environmental impacts are observed in both, with slightly better results for the seasonal storage case due to the simplified energy storage integration. The results show the moderate environmental impact of calcium looping thermochemical energy storage technology, resulting in lower equivalent carbon dioxide emissions 24 kg/MWh) than other energy storage options such as molten salt-based solar facilities (40 kg/MWh). Plant construction involves a higher energy demand for the process, whilst the operation and maintenance on the plant represent a moderate impact due to the low environmental impact of limestone, the unique raw material of the process, and the lower water consumption compared to typical concentrating solar power plants. Besides, the energy required for the system is first time analysed, obtaining an energy payback time of 2.2 years and 2.5 years depending on the storage strategy design.Unión Europea - Horizonte 2020 No 727348Junta de Andalucía PY20 RE00
Analysis of microbial populations in Rusitec fermenters fed diets of variable composition
Trabajo presentado al : Joint Annual Meeting. ADSA-ASAS. Orlando Florida (USA), julio, 2015. T485Fermenters are widely used to study ruminal fermentation, but
infonnation on microbial populations developing in fermenters over
the incubation period is limited. Four Rusitec fermenters were fed
2 diets representative of those administered to dairy sheep (DAI;
50:50 alfalfa hay:concentrate) and fattening lambs (FAT; 15:85 barley
straw:concentrate) in a crossover design with 2 14-d incubation periods to assess the evolution of the microbial populations. There were 4
fermenters per diet. The fermenters received daily 30 g of diet DM and
samples from liquid (LIQ) and solid (SOL) digesta were taken on d 3,
8 and 14, and stored frozen at-80ªC until DNA extraction. Concentrations ofbacterial and protozoal DNA and relative abundance offungi
and methanogenic archaea to total bacteria! DNA concentration were
detennined by real time PCR using previously validated primers and
DNA from bacteria and protozoa isolated from sheep rumen as standards. Data were analyzed as a mixed model with repeated measnres
using the PROC MlXED of SAS. The model included diet, incubation
nm, time, and diet x tin1e as fixed effects, and fermenter as a random
effect. Diet x sampling time interactions (P > 0.05) were detected for
bacteria! and protozoal DNA concentrations in both digesta phases. The
bacteria! DNA concentrations in SOL did not change (P = 0.002) over
the incubation period, whereas concentrations in LIQ increased (P <
0.001) by 1.5 and 1.8 times for DAI and FAT diets by the end ofthe
incubation, respectively. Protozoal DNA concentrations on d 14 were
37.8 and 8.0 times lower (P < 0.001; means across diets) than those on
d 3 for SOL and LIQ phases, respectively. Relative abundance offungi
decreased (P < 0.05) with time in both phases, and that ofmethanogenic archaea remain unchanged in LIQ and increased (P = 0.021) in
SOL. Concentration of bacteria! and protozoal DNA and the relative
abundance of methanogenic archaea were greater in the fermenters fed
the DAI diet (P < 0.05) compared with FAT diet. The results show that
microbial populations in Rusitec fermenters are affected by the incubated
diet and change over the incubation periodPeer reviewe
An overview of the ciao multiparadigm language and program development environment and its design philosophy
We describe some of the novel aspects and motivations behind
the design and implementation of the Ciao multiparadigm programming system. An important aspect of Ciao is that it provides the programmer with a large number of useful features from different programming paradigms and styles, and that the use of each of these features can be turned on and off at will for each program module. Thus, a given module may be using e.g. higher order functions and constraints, while another module may be using objects, predicates, and concurrency. Furthermore, the language is designed to be extensible in a simple and modular way. Another important aspect of Ciao is its programming environment, which provides a powerful preprocessor (with an associated assertion language) capable of statically finding non-trivial bugs, verifying that programs comply with specifications, and performing many types of program optimizations. Such optimizations produce code that is highly competitive with other dynamic languages or, when the highest levéis of optimization are used, even that of static languages, all while retaining the interactive development environment of a dynamic language. The environment also includes a powerful auto-documenter. The paper provides an informal overview of the language and program development environment. It aims at illustrating the design philosophy rather than at being exhaustive, which would be impossible in the format of a paper, pointing instead to the existing literature on the system
Determination of synthetic opioids in oral fluid samples using fabric phase sorptive extraction and gas chromatography-mass spectrometry
New psychoactive substances (NPS) continue to emerge in the drug market every year, becoming a global threat to public health and safety. These compounds are mostly synthetic cannabinoids and designer cathinones. However, synthetic opioids have appeared on the recreational drug markets in recent years, particularly fentanyl and its derivatives (“fentanyls”). Fentanyl and its analogs are related to harmful intoxications and an increase in opioid-related mortality in many countries, such as in the United States and Europe in the last years. Taking the drug related global crisis into consideration, this work developed and validated an effective and sensitive method based on fabric phase sorptive extraction (FPSE) followed by gas chromatography-mass spectrometry (GC-MS) for the simultaneous determination of 11 fentanyl analogs in oral fluid samples. The extraction was carried out using a sol-gel Carbowax 20 M sorbent immobilized on 100% cellulose fabric substrate and using ethyl acetate as the desorption solvent. The limits of detection (LODs) and quantification (LOQs) ranged from 1 to 15 ng mL−1 and 5 to 50 ng mL−1, respectively. Intra-day and inter-day precision were found within 8.2% and 8.6%, respectively, while accuracy ranged from -5.5 to 9.1%, in accordance with the established criteria. The absolute recovery values were in the range of 94.5%–109.1%. The validated method demonstrated its great potential to detect and quantify fentanyl analogs in possible forensic work and off-site analysis in road traffic casesThis work was supported by the Spanish Ministry of Science, Innovation, and Universities (Project RTI2018‐096450‐B‐I00) and FEDER fundsS
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