91 research outputs found
Warming increases the compositional and functional variability of a temperate protist community
Phototrophic protists are a fundamental component of the world's oceans by serving as the primary source of energy, oxygen, and organic nutrients for the entire ecosystem. Due to the high thermal seasonality of their habitat, temperate protists could harbour many well-adapted species that tolerate ocean warming. However, these species may not sustain ecosystem functions equally well. To address these uncertainties, we conducted a 30-day mesocosm experiment to investigate how moderate (12C) and substantial (18C) warming compared to ambient conditions (6C) affect the composition (18S rRNA metabarcoding) and ecosystem functions (biomass, gross oxygen productivity, nutritional quality – C:N and C:P ratio) of a North Sea spring bloom community. Our results revealed warming-driven shifts in dominant protist groups, with haptophytes thriving at 12 C and diatoms at 18 C. Species responses primarily depended on the species' thermal traits, with indirect temperature effects on grazing being less relevant and phosphorus acting as a critical modulator. The species Phaeocystis globosa showed highest biomass on low phosphate concentrations and relatively increased in some replicates of both warming treatments. In line with this, the C:P ratio varied more with the presence of P. globosa than with temperature. Examining further ecosystem responses under warming, our study revealed lowered gross oxygen productivity but increased biomass accumulation whereas the C:N ratio remained unaltered. Although North Sea species exhibited resilience to elevated temperatures, a diminished functional similarity and heightened compositional variability indicate potential ecosystem repercussions for higher trophic levels. In conclusion, our research stresses the multifaceted nature of temperature effects on protist communities, emphasising the need for a holistic understanding that encompasses trait-based responses, indirect effects, and functional dynamics in the face of exacerbating temperature changes
Алгоритм сжатия на основе вычисления скорости изменения ультразвукового сигнала
The intermittency structure of multihadronic e+e- annihilation is analyzed by evaluating the factorial moments F2-F5 in three-dimensional Lorentz invariant phase space as a function of the resolution scale. We interpret our data in the language of fractal objects. It turns out that the fractal dimension depends on the resolution scale in a way that can be attributed to geometrical resolution effects and dynamical effects, such as the pi-O Dalitz decay. The LUND 7.2 hadronization model provides an excellent description of the data. There is no indication of unexplained multiplicity fluctuations in small phase space regions
A three-step numerical approximant based on block hybrid backward differentiation formula for stiff system of ordinary differential equation
We present results of an analysis of the reaction in the two-photon process in the untagged mode. The cross section is largely compatible with previous determinations; however, we do not confirm the enhancement claimed at 1.9 GeV. All observed ω's are accompanied by ϱ's in the recoiling ππ spectrum. An angular correlation analysis shows that the data is not dominated by a single spin-parity state, thus establishing severe constraints on models which predict
Накопление газообразных продуктов деления и соединений в микрокапсулированном топливе в сверхдлинных кампаниях
The production of b and c quarks in annihilation has been studied with the CELLO detector in the range from 35 GeV up to the highest PETRA energies. The heavy quarks have been tagged by their semileptonic decays. The charge asymmetries for b quarks at 35 and 43 GeV have been found to be , respectively, using a method incorporating jet variables and their correlations for the separation of the heavy quarks from the back ground of the lighter quarks. For c quarks we obtain and , respectively. The axial vector coupling constants of the heavy quarks c and b are found to be and taking mixing into account. The results are in agreement with the expectations from the standard model
Разработка модульного стенда физического подобия для изучения гидротехнических систем
В рамках данной работы проведен обзор и анализ образовательных стендов, сформулирована концепция модульного стенда физического подобия, разработаны функциональные схемы двух модулей, в соответствии с которыми подобраны основные элементы. Для первого модуля предоставлены принципиальная схема и демонстрационный алгоритм работы.In this work, a review and analysis of educational booths, formulated the concept of modular stand physical similarity, developed functional diagrams of the two modules, in accordance with which the selected basic elements. For the first module, a schematic diagram and a demonstration algorithm are provided
Autothermal reforming of palm empty fruit bunch bio-oil: thermodynamic modelling
This work focuses on thermodynamic analysis of the autothermal reforming of palm empty fruit bunch (PEFB) bio-oil for the production of hydrogen and syngas. PEFB bio-oil composition was simulated using bio-oil surrogates generated from a mixture of acetic acid, phenol, levoglucosan, palmitic acid and furfural. A sensitivity analysis revealed that the hydrogen and syngas yields were not sensitive to actual bio-oil composition, but were determined by a good match of molar elemental composition between real bio-oil and surrogate mixture. The maximum hydrogen yield obtained under constant reaction enthalpy and pressure was about 12 wt% at S/C = 1 and increased to about 18 wt% at S/C = 4; both yields occurring at equivalence ratio Φ of 0.31. The possibility of generating syngas with varying H2 and CO content using autothermal reforming was analysed and application of this process to fuel cells and Fischer-Tropsch synthesis is discussed. Using a novel simple modelling methodology, reaction mechanisms were proposed which were able to account for equilibrium product distribution. It was evident that different combinations of reactions could be used to obtain the same equilibrium product concentrations. One proposed reaction mechanism, referred to as the ‘partial oxidation based mechanism’ involved the partial oxidation reaction of the bio-oil to produce hydrogen, with the extent of steam reforming and water gas shift reactions varying depending on the amount of oxygen used. Another proposed mechanism, referred to as the ‘complete oxidation based mechanism’ was represented by thermal decomposition of about 30% of bio-oil and hydrogen production obtained by decomposition, steam reforming, water gas shift and carbon gasification reactions. The importance of these mechanisms in assisting in the eventual choice of catalyst to be used in a real ATR of PEFB bio-oil process was discussed
Reviewing the potential and cost-effectiveness of grid-connected solar PV in Indonesia on a provincial level
\u3cp\u3ePhotovoltaic (PV) energy could play a large role in increasing the electrification ratio and decreasing greenhouse gas emissions in Indonesia, especially since Indonesia comprises over 17,000 islands which is a challenge for the distribution of fuels and modern grid connection. The potential of grid-connected PV depends on, a.o. population, electrification ratio, irradiance, electricity demand, electricity generation costs and the urbanization ratio. Large spatial differences exist for these factors in Indonesia, therefore this study aims to assess the energetic potential and cost-effectiveness of grid-connected PV in Indonesia on a provincial level. Taking restrictions of the electricity demand during day-time and a minimal base load of conventional power systems into account, the total potential of grid-connected PV systems is about 27 GWp, generating 37 TWh/year, which is about 26% of the total electricity consumption in Indonesia over 2010. In the eastern provinces of Indonesia the LCOE of PV in grid-connected urban areas is lower than the cost of present electricity generation and could be a viable alternative if excluding high subsidies for electricity production.\u3c/p\u3
Real-time irradiance simulation for PV products and building integrated PV in a virtual reality environment
\u3cp\u3eThis paper describes a new software tool named VR4PV, which has been developed for real-time simulation of irradiance for photovoltaic (PV) products in a virtual 3-D environment. This tool offers the possibility for product designers and architects to evaluate the distribution of irradiance on surfaces with an arbitrary geometry that can be covered with PV cells. In addition, the energetic performance can be estimated during the design process of PV products and building integrated PV (BIPV). The software allows for irradiance calculations on multiple arbitrarily oriented surfaces at the same time. It includes shadow simulation for multiple surrounding objects with various shapes and can handle movements of the 3-D objects during the simulation, which might be useful for the design of moving PV-powered products like boats, cars, and portable handhelds. A validation is carried out based on 1-min outdoor measurements of irradiance on two different locations in Italy and in California.\u3c/p\u3
Experiences of end-users of the electricity grid
\u3cp\u3eThis chapter explores the reliability of electricity supply in Indonesia.\u3c/p\u3
Status and challenges of electricity supply
\u3cp\u3eIn this chapter, we will present the status of the energy and electricity supply and demand in Indonesia, challenges in providing electricity to the whole population, power supply systems and businesses, and the status of renewable implementation.\u3c/p\u3
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