Against the background of carbon peak and carbon neutralization, in order to solve the problem of poor flexibility of integrated energy systems and wind power consumption while improving the potential of hydrogen energy emission reduction, this study proposes an integrated energy system that takes into account the coupling of concentrating solar power (CSP), hydrogen-doped combustion, and power-to-gas (P2G) conversion. Firstly, a mathematical model of a CSP-CHP unit is established by introducing a CSP power station, aiming at the defect of the “heat to power” mode in the CHP system. Secondly, the energy consumption of P2G hydrogen energy production is satisfied by surplus wind power. The utilization stage of hydrogen energy is divided into supply CHP combustion and CO2 methanation, forming a CSP-P2G-HCHP collaborative framework and establishing an IES low-carbon economic dispatch model with CSP-P2G-HCHP. At the same time, the carbon trading mechanism is introduced to constrain the carbon emissions of the system. Finally, an optimization strategy with the minimum sum of the operation and maintenance cost, the energy purchase cost, the wind curtailment cost, and the carbon emission cost as the objective function is proposed, and the CPLEX solver is used to solve and carry out multi-case analysis. The simulation results show that the carbon emissions are reduced by 6.34%, the wind curtailment cost is reduced by 52.2%, and the total cost is reduced by 1.67%. The model takes into account the carbon reduction effect and operating efficiency and effectively improves the new energy consumption capacity.
The aim of this work is to study the effect of gold nanoparticles on the segmental dynamics, glass transition (Tg) and physical aging of polystyrene (PS). To do so, PS/gold nanocomposite samples containing 5 and 15 wt% of 60 nm spherical gold nanoparticles, surface-treated with thiolated-PS, were prepared. The segmental dynamics of PS, as measured by means of broadband dielectric spectroscopy (BDS), was found to be unchanged in the presence of gold nanoparticles. Conversely, the calorimetric Tg of PS was shown to decrease with increasing the amount of gold nanoparticles in the samples. Furthermore, by measuring the amount of recovered enthalpy of PS—by means of DSC—after annealing at temperatures below Tg for various aging times, the physical aging was shown to speed up with increasing the nanoparticles weight fraction, i.e. the amount of PS/gold interface in the hybrid material. Thus, the main conclusion of our work is that PS molecular mobility and the out-of-equilibrium dynamics are markedly decoupled in these nanocomposites. The significant effect of the amount of PS/gold interface on both the physical aging rate of PS and the depression of the calorimetric Tg in the presence of nanoparticles is quantitatively accounted for by a model based on the diffusion of free volume holes towards polymer interfaces, with a diffusion coefficient depending only on the molecular mobility.
Abstract Genetic variation is usually estimated empirically from statistics based on population gene frequencies, but alternative statistics based on allelic diversity (number of allelic types) can provide complementary information. There is a lack of knowledge, however, on the evolutionary implications attached to allelic-diversity measures, particularly in structured populations. In this article we simulated multiple scenarios of single and structured populations in which a quantitative trait subject to stabilizing selection is adapted to different fitness optima. By forcing a global change in the optima we evaluated which diversity variables are more strongly correlated with both short- and long-term adaptation to the new optima. We found that quantitative genetic variance components for the trait and gene-frequency-diversity measures are generally more strongly correlated with short-term response to selection, whereas allelic-diversity measures are more correlated with long-term and total response to selection. Thus, allelic-diversity variables are better predictors of long-term adaptation than gene-frequency variables. This observation is also extended to unlinked neutral markers as a result of the information they convey on the demographic population history. Diffusion approximations for the allelic-diversity measures in a finite island model under the infinite-allele neutral mutation model are also provided.
We present a fast and flexible software package--SimPhy--for the simulation of multiple gene families evolving under incomplete lineage sorting, gene duplication and loss, horizontal gene transfer--all three potentially leading to species tree/gene tree discordance--and gene conversion. SimPhy implements a hierarchical phylogenetic model in which the evolution of species, locus, and gene trees is governed by global and local parameters (e.g., genome-wide, species-specific, locus-specific), that can be fixed or be sampled from a priori statistical distributions. SimPhy also incorporates comprehensive models of substitution rate variation among lineages (uncorrelated relaxed clocks) and the capability of simulating partitioned nucleotide, codon, and protein multilocus sequence alignments under a plethora of substitution models using the program INDELible. We validate SimPhy's output using theoretical expectations and other programs, and show that it scales extremely well with complex models and/or large trees, being an order of magnitude faster than the most similar program (DLCoal-Sim). In addition, we demonstrate how SimPhy can be useful to understand interactions among different evolutionary processes, conducting a simulation study to characterize the systematic overestimation of the duplication time when using standard reconciliation methods. SimPhy is available at https://github.com/adamallo/SimPhy, where users can find the source code, precompiled executables, a detailed manual and example cases.
: Tuesday, June 15, 2004: POSTER SESSIONS: Poster Session 23: BP Measurements and Hemodynamics
Objectives: Administration of angiotensin-receptor blockers (ARB) at bedtime as opposed to upon wakening increases the sleep-time relative blood pressure (BP) decline and their efficacy in lowering nocturnal BP. Urinary albumin excretion in non-dippers has been shown to be significantly greater than in dippers, although the potential effects on renal function of reverting the non-dipping pattern have not been clearly elucidated. Accordingly, we evaluated the administration-time-dependent effects on urinary albumin excretion of treatment with ARB in subjects with essential hypertension. Methods: We studied 815 untreated non-proteinuric hypertensive subjects (321 men), 48.7 ± 13.5 years of age, assigned to receive an ARB in monotherapy either on awakening or at bedtime. BP was measured at 20-min intervals from 07:00 to 23:00 h and at 30-min intervals at night for 48 h before and after 12 weeks of treatment. The subjects collected their urine during the first 24 h of each BP monitoring session. Results: The reduction in awake BP was similar for both treatment-times. Treatment at bedtime, however, was significantly more efficient in reducing asleep BP (17.2 versus 11.2 mmHg after morning treatment; P < 0.001). The sleep-time relative BP decline was increased towards a more dipping pattern only after bedtime dosing (P < 0.001). Urinary albumin excretion was significantly reduced after treatment, and to a significant larger extent after bedtime dosing (P = 0.032). This albumin reduction was independent of the change in awake BP after treatment, but highly correlated with both the decrease in asleep BP and the increase in sleep-time relative BP decline (r = 0.321; P < 0.001), independently of treatment-time. Conclusions: Bedtime administration of ARB provides higher efficacy, as compared to morning treatment, in reducing the asleep BP mean, and improves the sleep-time relative BP decline towards a more dipper profile. This might be clinically relevant, as nighttime BP is a better prognostic marker of cardiovascular mortality than awake BP. Most important, the normalization of the circadian BP pattern towards a more dipper profile is associated with a significant decrease in urinary albumin excretion.
The standard bivalve embryos-larval bioassay method has been modified for monitoring the water quality in an important mussel culture area, La Rochelle Bay. Fertilised eggs from naturally spawned Mytilus galloprovincialis mussels were incubated for 48 h at 18 ± 1 degree C, in different water samples (five replicates) from the bay and its surroundings. The mean percentages of abnormalities, with the 95 % confidence limit, of controls and different water samples were compared. The method was shown to allow the application of the the bioassay to fresh, brackish and marine waters. The assessment of the water quality of the different tributaries to the Bay and that of freshwaters from intensively cultivated marshes close to it, showed that it varied form toxic to lethal, according to Woelke's classification. In contrast, the seawater of the mussel culture area was unpolluted.
