The concentrations of macro elements (Ca, K, Mg, and Na), essential trace elements (Cr, Cu, Fe, Li, Mn, Ni, and Zn), and nonessential trace elements (Al, As, Cd, Pb, and Ti) in the shell and soft ...tissues of Perna perna (L. 1758) mussels from Southeast Brazil are presented as a baseline reference for understanding the effects of the COVID-19 pandemic on the quality of coastal environments. For shells, the macro elements load was greater during the pandemic period at all sampling sites; however, for soft tissues, the opposite trend was recorded. On the contrary, the concentrations of trace elements in the shell were below the limit of quantification in most samples, and they tended to decrease in the soft tissues during the pandemic. Thus, the COVID-19 was a short-term conservation event that positively impacted the mussels. The results are relevant for monitoring the coastal environment in a post-COVID-19 scenario.
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•Mussels were analyzed for macro elements and trace elements.•Trace elements were below the LOQ in most shells during the pandemic.•Trace elements in soft tissues tended to decrease during the pandemic.•Pandemic restriction was a short-term event that positively impacted the mussels.
Summary
We investigate a macro‐element variant of the hybridized discontinuous Galerkin (HDG) method, using patches of standard simplicial elements that can have non‐matching interfaces. Coupled via ...the HDG technique, our method enables local refinement by uniform simplicial subdivision of each macro‐element. By enforcing one spatial discretization for all macro‐elements, we arrive at local problems per macro‐element that are embarrassingly parallel, yet well balanced. Therefore, our macro‐element variant scales efficiently to n‐node clusters and can be tailored to available hardware by adjusting the local problem size to the capacity of a single node, while still using moderate polynomial orders such as quadratics or cubics. Increasing the local problem size means simultaneously decreasing, in relative terms, the global problem size, hence effectively limiting the proliferation of degrees of freedom. The global problem is solved via a matrix‐free iterative technique that also heavily relies on macro‐element local operations. We investigate and discuss the advantages and limitations of the macro‐element HDG method via an advection‐diffusion model problem.
A discrete‐element approach accounting for P‐Delta effects Cusmano, Valeria; Pantò, Bartolomeo; Rapicavoli, Davide ...
Earthquake engineering & structural dynamics,
June 2023, 2023-06-00, 20230601, Volume:
52, Issue:
7
Journal Article
Peer reviewed
Open access
This paper presents a discrete macro‐element accounting for P‐Delta effects to describe the rocking response of masonry walls subjected to out‐of‐plane (OOP) loadings. Both constitutive and geometric ...nonlinearities are considered within the discrete macro‐element method (DMEM), which is a modeling approach characterized by a very low computational cost compared to traditional distinct element method (DEM) and detailed finite element (FEM) strategies. OOP failure mechanisms are the main cause of severe damage for unreinforced masonry (URM) buildings, subjected to seismic actions. These mechanisms are generally activated by low seismic excitation and displacements. However, after their activation, they can evolve towards large displacements related to rigid‐block‐like kinematics that strongly affects the nonlinear mechanical response. Therefore, geometric nonlinearities, often ignored, should be included in the analyses. A new simplified, still accurate P‐Delta formulation is presented, according to which the global equilibrium is imposed by referring to the undeformed system configuration, avoiding assembling the geometric stiffness matrix. Namely, the system load vector is updated at each step of the analysis, accounting for the additional moments generated by the in‐plane compression forces acting on the macro‐elements in the deformed configuration. The proposed model is validated against closed‐form analytical solutions of rigid‐block benchmarks in large displacements and the results of experimental tests already available in the literature. In addition, extensive parametric analyses are performed to investigate the role of different mechanical and geometric parameters characterizing the ultimate non‐linear response of masonry walls subjected to horizontal forces. The results show how the proposed model, including P‐Delta effects, accurately predicts the non‐linear rocking response of masonry walls until the attainment of the unstable configuration.
Excess water is an abiotic stress in plants, but the level at which excess water becomes varies widely between plant species. We conducted a two growing season replicated excess flooding experiment ...that was planted with 24 accessions of perennial ryegrass which had been vegetatively propagated to ensure equal representation of genotypes within an accession, both cultivars and ecotypes, from various geographical origins. The excess water treatment applied over the winter periods was achieved with irrigation. Yields increased in the winter-flooded treatment in contrast to the non-artificial watered control treatment significantly in 2017. In 2018 the same trend could be seen, but was not significant. Differences in composition of macro- and micronutrient profiles were observed. Sulphur was the only element with highly significantly increased concentration (0.25%) in flooded samples compared to control. Phosphorus, copper, iron, manganese, and molybdenum decreased statistically significantly under flooded conditions. In conclusion, perennial ryegrass is coping extremely well with excess water supplied over the winter period and can utilise it effectively in spring.
This study aims to investigate the influence of three different dichromatic LED light sources and varying photoperiod durations on the mineral content and trace element compositions in cultivated ...Gongolaria barbata under controlled culture conditions. During the experiment, red-blue (RB), blue-green (BG), red-green (RG) and fluorescent lights were examined at 16:16, 12:12, and 8:16 Light: Dark (L:D) photoperiods, and at 150 μmol photon m-2 s-1 intensity of light in all treatments. The elemental compositions of the thallus samples were analyzed for Mg, Ca, K, Na, P, Zn, Mo, Cu, Mn, Cr, Co, Cd, Fe, and As.. Our results showed that macro element and trace element compositions significantly varied among different experimental groups. Regarding the order of abundance, macroelements were ranked as follows: K > Na > Ca > Mg > P. Meanwhile, trace elements followed this order: As > Zn > Mn > Cr > Co > Cu > Cd > Mo > Fe. Among the experiment groups, the highest value of the macro elements was recorded as 1041.3±22.2 mg kg-1 for K, and the lowest value was 26.61±0.02 mg kg-1 for the P. Among the trace elements, for As, the highest value was recorded as 1339.86±5.27 µg kg -1, and the lowest was determined at 1.93±0.04 mg kg-1 for the Fe. The findings highlight that LED lighting conditions can significantly influence the elemental composition of G. barbata.
Bu çalışmanın amacı, kontrol koşullarında yetiştirilen Gongolaria barbata’nın mineral içeriği ve iz element değişimleri üzerinde üç farklı dikromatik LED ışık ve değişen fotoperiyot sürelerinin etkisini araştırmaktır. Deneme aşamasında, kırmızı-mavi (RB), kırmızı-yeşil (RG), mavi-yeşil (BG) ve floresan (F) LEDler, sırasıyla 16:16, 12:12 ve 8:16 Aydınlık:Karanlık (L:D) fotoperiyotlarında, her biri 150 μmol photon m-2 s-1 yoğunluğunda incelenmiştir. Tallusların; Ca, K, Mg, Na, P, Zn, Mo, Mn, Fe, Cu, Cr, Co, Cd ve As kompozisyonları analiz edilmiştir. Sonuçlarımıza göre, makroelement ve iz element kompozisyonları farklı deney grupları arasında önemli varyasyonlar gösterdi. Türde bulunan makroelementlerin sıralaması şu şekildedir: K > Na > Ca > Mg > P, aynı zamanda iz elementler şu sırayı takip etmektedir: As > Zn > Mn > Cr > Co > Cu > Cd > Mo > Fe. Deneme grupları arasında, makro elementlerin en yüksek değeri K elementi için 1041.3±22.2 mg kg-1 olarak belirlenirken, en düşük değer P için 26.607±0.02 mg kg-1 olarak belirlendi. İz elementler arasında ise en yüksek değer As için 1339.86±5.27 µg kg-1 tespit edilirken, en düşük değer Fe için 1.930±0.04 mg kg-1 olarak belirlendi. Bulgular, LED aydınlatma koşullarının G. barbata türünün elementel kompozisyonunu önemli ölçüde etkileyebileceğini vurgulamaktadır.
Abstract
We present a mesh-independent and parameter-robust multigrid solver for the Scott–Vogelius discretisation of the nearly incompressible linear elasticity equations on meshes with a macro ...element structure. The discretisation achieves exact representation of the limiting divergence constraint at moderate polynomial degree. Both the relaxation and multigrid transfer operators exploit the macro structure for robustness and efficiency. For the relaxation we use the existence of local Fortin operators on each macro cell to construct a local space decomposition with parameter-robust convergence. For the transfer we construct a robust prolongation operator by performing small local solves over each coarse macro cell. The necessity of both components of the algorithm is confirmed by numerical experiments.
Riparian woodlands play a multiple ecological and environmental role, including control of non-point source pollution and increasing of nutrients retention. Four riparian species (Arundo donax L., ...Salix purpurea L., Populus euphratica Olivier and Tamarix gallica L.) were tested comparatively in tertiary treatment and/or secondary one under a Mediterranean climate. Mesocosm inlets and outlets have been sampled every two weeks, during 21 successive months, and analyzed to determine nitrogen (N) and phosphorus (P) contents. Growth, biomass production and/or NP contents of macrophytes were monitored during three successive vegetation periods. Results show that A. donax presents a higher growth rate (2.39 cm d−1) during the vegetation period, and a large harvestable biomass (118–134 t dry weight.ha−1.y−1) and aboveground N/P accumulation (1.55–2.13 t N.ha−1.y−1/0.16–0.17 t P.ha−1.y−1). S. purpurea and T. gallica show medium performances in this respect. In addition, A. donax-Mesocosm retains more particulate and dissolved forms of total nitrogen and total phosphorus, and orthophosphates in both treatment levels. In tertiary treatment, the annual collecting of aboveground biomass contributes to the export of 31.4% N-14.1% P and 14.5% N-7.71% P removed, by A. donax and T. gallica mesocosms in the same order. Collecting biomass of riparian plant grown in subsurface flow constructed wetland promotes more N retention when compared to the P one.
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•Four riparian plants have been experimented for urban wastewater treatment.•Arundo donax produces a large harvestable biomass than other three species.•A. donax stores more nitrogen and phosphorus in its aboveground parts.•Collecting biomass is more profitable for the N retention than the P one.
Cereal straw, including wheat one, is widely used in animal husbandry. Wheat straw is used as bedding and a component of rations. Violation of storage conditions and excessive volumes of harvesting ...causes a large mass of straw to deteriorate every year, which has a negative impact on the environment. Uncontrolled rotting of straw increases the amount of gas emissions into the air. An effective way of disposing of spoiled wheat straw is its fermentation using biological preparations to obtain biocompost. The problem of the effectiveness of composting spoiled wheat straw using the domestic biodestructor BTU-CENTER remains unexplored. The aim of the work was to determine the effect of different doses of the BTU-CENTER biodestructor on the physical and chemical parameters of fermented wheat straw. For the experiment, 4 groups of piles were formed. In the piles from the control group, straw composting was carried out without the use of a biodestructor. A biodestructor was added to the straw from the 1st experimental group at the rate of 7.0 cm3/t of biomass with a moisture content of 65.5 %. Spoiled straw in the II and III experimental groups was treated with a biodestuctor solution, providing its doses in the range of 14.0 and 28.0 cm3/t. Aeration of the piles was carried out by stirring the straw periodically every 8 days. During composting, the temperature of the straw biomass in the middle of the piles was determined. The content of crude protein, Phosphorus, Calcium and Nitrogen was determined in the fermented straw. It has been established that the heating of straw in the piles started from the second day of composting. An increase in the temperature of the biomass in the experimental piles was observed up to the 12th day, and in the control group up to the 14th day of composting. It was found that the higher the dose of the biodestructor used during straw processing, the higher the temperature in the middle of the piles. In the III experimental group, on the 12th day of composting, the highest straw temperature was established in the middle of the piles. The difference with control, I and II experimental groups was 21.4; 15.9 and 4.1 % respectively. The longest fermentation of wheat straw under the thermophilic regime was established in the group where the highest dose of biodestructor was used – 18 days. It has been proved that the use of high doses of the biodestructor increases the content of crude protein, Nitrogen, Phosphorus and Calcium in the fermented wheat straw biomass relatively to the control one.
In this study, the quantification of macro, micro and toxic elements in milk and its products was carried out using inductively coupled plasma optical emission spectrometry (ICP-OES) after using ...sample preparation procedures (wet digestion, dry digestion, and microwave digestion). Samples were collected from farms and markets in Edirne, Turkey. Ca, Mg, Na, K, Cu, Fe, Mn, Zn, Al, and Ba concentrations in the farm milk and its products ranged from 823 to 1499, 109–476, 218–1498, 905–1694, 0.094–0.26, 2.0–3.7, 0.014–0.105, 1.2–5.2, 0.192–0.35 and 0.075–0.191mgkg−1 respectively. The results in commercial milk and milk based products (minimum-maximum in mg·kg−1) were: Ca 791–1518, Mg 107–518, Na 221–1594, K 901–1692, Cu 0.068–0.23, Fe 2.2–4, Mn 0.019–0.087, Zn 2–5, Al 0.124–0.40 and 0.080–0.197. Macro, micro and toxic element contents of the commercial milk and its products in this study generally were higher than that of the natural samples. However, a tolerable daily diet of these elements by the Trakya region is well below the Turkish Food Codex (TFC) levels of macro, micro and toxic elements.
•Macro, micro and toxic elements in both cow's milk and milk-based products were determined by ICP-OES•Wet digestion, dry digestion, and microwave digestion procedures were discussed.•Ca, Mg, Na, K, Cu, Fe, Mn, Zn, Al, and Ba concentrations were compared with Turkish Food Codex levels.
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