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Literatura académica sobre el tema "Wood accumulation"

Autor: Grafiati

Publicado: 10 de marzo de 2023

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Artículos de revistas sobre el tema "Wood accumulation"

Wyss, Andris, Isabella Schalko y Volker Weitbrecht. "Field Study on Wood Accumulation at a Bridge Pier". Water 13, n.º 18 (9 de septiembre de 2021): 2475. http://dx.doi.org/10.3390/w13182475.

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Transported large wood (LW) in rivers may block at river infrastructures such as bridge piers and pose an additional flood hazard. An improved process understanding of LW accumulations at bridge piers is essential for a flood risk assessment. Therefore, we conducted a field study at the River Glatt in Zurich (Switzerland) to analyze the LW accumulation process of single logs at a circular bridge pier and to evaluate the results of previous flume experiments with respect to potential scale effects. The field test demonstrated that the LW accumulation process can be described by an impact, rotation, and separation phase. The LW accumulation was described by combining two simplified equilibria of acting forces and moments, which are mainly a function of the pier diameter, pier roughness, and flow properties. We applied the resulting analytic criterion to the field data and demonstrated that the criterion can explain the behavior of 82% of the logs. In general, the field observations confirmed previous results on the LW accumulation probability in the laboratory, which supports the applicability of laboratory studies to investigate LW–structure interactions.

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Corotis, Ross B. y Daniel P. Sheehan. "Wood Damage Accumulation by Stochastic Load Models". Journal of Structural Engineering 112, n.º 11 (noviembre de 1986): 2402–15. http://dx.doi.org/10.1061/(asce)0733-9445(1986)112:11(2402).

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Spreitzer, Gabriel, Heide Friedrich y Jon Tunnicliffe. "Effects of a large woody debris accumulation on channel-bed morphology during flood events". E3S Web of Conferences 40 (2018): 02024. http://dx.doi.org/10.1051/e3sconf/20184002024.

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A novel experimental setup for the laboratory was designed in order to investigate large woody debris accumulations and their influence on hydraulic flow conditions and channel morphology at a river cross-section. Real wood and mobile gravel bedload material were used to simulate morphodynamic interactions in a headwater stream, based on a New Zealand prototype river. The survey methodology employs Structure from Motion techniques, using an advanced multi-camera-array. In this study we present the experimental setup and initial results from our first experiments. With this research project we aim to investigate the dynamics of jam initiation and the characteristic evolution of the jam, for a given discharge, sediment load, and distribution of woody material. Furthermore, this study will elaborate more practical and efficient methodologies for observing wood jams, both in the laboratory and in the field. The project expands current knowledge about interaction processes between flow, sediment and woody debris, which are presently poorly understood and still represent a gap in research.

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Medvedeva, M. V., T. S. Titova, O. N. Bakhmet, A. N. Pekkoev y V. A. Kharitonov. "Investigation of the Influence of Aerotechnogenic Pollution on the Accumulation of Heavy Metals in the Plant-Soil System". Ecology and Industry of Russia 23, n.º 6 (11 de junio de 2019): 52–57. http://dx.doi.org/10.18412/1816-0395-2019-6-52-57.

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It is shown that the chemical composition of the litter falls and wood of deciduous and coniferous trees is different. On the background of aerotechnogenic pollution, accumulation of individual heavy metals, an increase in ash content was noted. There was revealed the anthropogenic dynamics of the accumulation of heavy metals in the wood of trees: the maximum number during the period of diesel traction; as the railway site is electrified, the accumulation of elements decreases. The obtained data can be recommended to be used for phytoremediation at sites subject to pollution. The obtained data will be the basis for assessing the phytoextractive potential of woody plants, in diagnosing aero-technogenic pollution of the environment, solving the problem of reducing environmental risks, as well as during the modernization and planning of environmental measures in the field of railway infrastructure.

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Li, Zheng, Duo Tao, Mengwei Li, Zhan Shu, Songshi Jing, Minjuan He y Peng Qi. "Prediction of Damage Accumulation Effect of Wood Structural Members under Long-Term Service: A Machine Learning Approach". Materials 12, n.º 8 (16 de abril de 2019): 1243. http://dx.doi.org/10.3390/ma12081243.

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It is well known that wood structural members can stand a relatively heavy load in the short term but will gradually get weaker if the load is applied for a longer period. This phenomenon is caused by the damage accumulation effect in wood and should be appropriately considered during the design of timber structures. Although various formulation methods (also known as classical models) have been proposed to evaluate the damage accumulation effect in wood, the calibration of model parameters is very time-consuming. Our work proposes a novel method to deal with the damage accumulation effect in wood that involves the application of machine learning algorithms. The proposed algorithm considers a multi-objective optimization process with a combination of goodness-of-fit and complexity. Long-term experimental data of typical wood species are used for developing the machine learning based damage accumulation model. Compared with existing pre-formulated models, our model managed to reduce the complexity of the model structure and give sufficiently accurate and unbiased predictions. This study aims to provide a novel tool for evaluating the damage accumulation in wood structural members, and the proposed model can further support the life-cycle performance assessment of timber structures under long-term service scenarios.

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Maass, J. Manuel, Angelina Martínez-Yrízar, Cristina Patiño y José Sarukhán. "Distribution and annual net accumulation of above-ground dead phytomass and its influence on throughfall quality in a Mexican tropical deciduous forest ecosystem". Journal of Tropical Ecology 18, n.º 6 (25 de septiembre de 2002): 821–34. http://dx.doi.org/10.1017/s0266467402002535.

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The amount and annual net accumulation of above-ground dead woody material were quantified in a tropical deciduous forest in western Mexico. Three plots were located within a small watershed (16 ha) and distributed along a 150-m-elevation gradient (Upper, Middle and Lower plot). Total amount of above-ground dead phytomass (fine + coarse) was 27.2 Mg ha-1. Coarse dead category (branches + logs) made up 70.6% (19.2 Mg ha-1) of the total. The rest comprised the fine fraction, which was lying on the forest floor as surface litter. Of the total coarse dead woody mass, 70.8% was standing, hanging or still attached to live trees (13.6 Mg ha-1). Dead wood net accumulation was 6.6 Mg ha-1 y-1; 58% of this was coarse woody material and the rest comprised the fine litterfall fraction. The amount of standing, hanging/attached dead branches (2-20 cm circumference) varied significantly among plots, with the highest value in the Upper plot. Dead wood net accumulation was similar between the Upper and Middle plots, and significantly higher than the Lower plot. Compared to the intact canopy, the removal of dead mass (hanging/attached dead branches and standing dead logs) caused a significant decrease in throughfall nutrient concentration and nutrient flux by this pathway.

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Storozhenko, V. G. "COMPARATIVE ASSESSMENT OF THE SUCCESSION DYNAMICS OF WOOD FRACTIONS OF SPRUCE FORESTS OF THE SOUTHERN TAIGA". FOREST SCIENCE ISSUES 5, n.º 3 (30 de septiembre de 2022): 1–14. http://dx.doi.org/10.31509/2658-607x-202252-109.

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Relevance. The native forests can be recognized as endangered formations of the European North of Russia. They are benchmarks of forest sustainability for comparative assessment with forests of other origin and use, what determines the relevance of research on their structural features. The purpose of the research is to conduct a comparative assessment of dynamic processes in the native forests of spruce formations of the southern taiga subzone of various successional positions (phases of dynamics) in the time trend of their development. Material and methods. Native spruce forests of different ages of the southern taiga subzone of the Central Forest Biosphere Reserve (Tver region) and the Kologrivsky Forest Reserve (Kostroma region) were researched various dynamic characteristics and successional position — climax, demutation, digressive. In the biogeocenoses of the sample areas, the age of trees and the presence of rot were determined, age series were built, the volumes of trees in age generations were calculated. All the tree fractions of the analyzed spruce forests were arranged in one time series: stands, current tree fall and deadfall — from retrospective values (– 60 years) to prospective values of the age limit of trees of the first generations of stands (+ ~ 300 years). The processes of dynamics of volumes of the wood fraction of native spruce forests of various successional positions in a long time space with different rates of accumulation and decomposition of wood biomass are described. Results and discussion. The processes of accumulation of biomass and the formation of age structures of biogeocenosis are 4 to 7 times slower than the processes of decomposition of the dying biomass of woody decay. Wood-destroying fungi of the saprotrophic complex “adjust” the activity of the decomposition process of wood decay to the dynamics of wood accumulation by the stand, maintaining the balance of accumulation and decomposition of woody biomass in the forest community. The correlation dependence of the increase in the values of tree infestation with wood-destroying fungi in age generations with an increase in their age is expressed in correlation coefficients from r — 0.89 at mr — 0.07 and t — 11.8 (spruce grove 1) to 0.99 at mr — 0.004 and t — 245 (spruce grove 4). The connection in both cases is very high, almost functional, which can be interpreted as a pattern. Conclusion. In native virgin forests, the balance of reproducible and decomposable wood is preserved as one of the most important criteria for the sustainable functioning of forest communities. This position can be regarded as an important fact of the evolutionary functional structure of forests.

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Pagliara, Stefano y Iacopo Carnacina. "Influence of Wood Debris Accumulation on Bridge Pier Scour". Journal of Hydraulic Engineering 137, n.º 2 (febrero de 2011): 254–61. http://dx.doi.org/10.1061/(asce)hy.1943-7900.0000289.

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Schalko, Isabella, Lukas Schmocker, Volker Weitbrecht y Robert M. Boes. "Laboratory study on wood accumulation probability at bridge piers". Journal of Hydraulic Research 58, n.º 4 (18 de julio de 2019): 566–81. http://dx.doi.org/10.1080/00221686.2019.1625820.

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Gabriel, J., M. Mokrejš, J. Bílý y P. Rychlovský. "Accumulation of heavy metals by some wood-rotting fungi". Folia Microbiologica 39, n.º 2 (abril de 1994): 115–18. http://dx.doi.org/10.1007/bf02906805.

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Tesis sobre el tema "Wood accumulation"

Kitts, Duncan Renfield. "The hydraulic and hydrological performance of large wood accumulation in a low-order forest stream". Thesis, University of Southampton, 2010. https://eprints.soton.ac.uk/185791/.

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Large wood and its accumulations are poorly understood despite being an important feature in the functioning of forested river channels and floodplains. Large wood has previously been removed from rivers in order to reduce flow resistance and increase channel conveyance. However, recently there has been an appreciation of the role of large wood accumulations in creating important aquatic habitat, increasing geomorphic diversity, re-connecting river channels to their floodplains and in the development of multi-channel anastomosed river patterns. This thesis examines the role that large wood plays at a range of scales in a low-order forested stream in the New Forest, Southern England. The study river was subject to restoration measures, involving the addition of large wood to the river channel, as part of an EU LIFE III project. An empirical and Froude-scaled flume approach is taken to determine the role of large wood accumulations upon the reach-scale flow resistance values. Large wood accumulations from a variety of environments are assessed to determine the hydraulic effects of accumulations of different architecture in different environments. Field data from the study catchment is used to show the role of large wood in increasing the frequency and duration of reach-scale, floodplain inundation. Hydrological data shows the impact the restoration has upon both flood peak magnitude and flood peak travel time highlighting the potential benefits of large wood to downstream flood risk. A 2-Dimensional model is produced which simulates the effect of a range of large wood accumulations upon the inundation extent. An approach using spatial diversity metrics, widely used in ecological sciences, is conducted in an attempt to quantify the flow depth and flow velocity diversity, which can influence flow habitat diversity. Results show that large wood can initiate an anastomosing flow pattern which allows increases flow depth diversity by up to 49% and flow velocity diversity by up to 48%

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Chiriboga, April Therese. "Longitudinal Variation in Wood Accumulation along the Stem of Populus Grandidentata; Implications for Forest Carbon Monitoring". Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/578835.

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The world's forests sequester roughly a quarter of anthropogenic emissions of carbon dioxide and store it in wood. Assessing this carbon sink includes quantifying annual wood production, establishing baselines, and characterizing both long-term trends and inter-annual variability. Direct measures of forest wood production are often based on measures of individual tree growth along the stem, often taken at a single height: basal height (1.3 meters). This assumes that a measurement of wood production at a single height is representative of wood production along the whole stem. In violation of this assumption, it is known that trees do accumulate wood differentially along the stem, and that this longitudinal variability can change from year to year. Few efforts have been made to describe annual longitudinal variability, and quantify the error in estimated annual whole-stem wood production related to assuming that constant wood production along the stem. In the present study, I present a stem analysis of 30 Populus grandidentata to address this. Dendrochronological techniques are used to develop three chronologies: a traditional tree-ring width chronology from basal height, a novel chronology developed from tree rings grown in the crown of the trees, and a specific volume increment chronology calculated from measured annual volume increment data. A novel taper chronology is also presented. In Chapter 2, comparisons are made between the chronologies to explore differences in inter-annual variability, and the suitability for using tree-ring data from basal height as a proxy for annual wood production. Both basal and crown tree-ring width chronologies were strongly correlated with the volume chronology (r = 0.96 and 0.88, respectively), suggesting that the basal chronology is a superior proxy for stem volume. However, a chronology of taper along the stem indicates that the reliability of either chronology to represent specific volume increment (SVI) changes over time, resulting in different common signals, especially in the last decade of this dataset. If accurately capturing the relative year-to-year changes in stem wood volume is desired, stem dissection and development of an SVI chronology is required. In Chapter 3, two models that use tree-ring data to estimate annual wood production are compared to volume measurements from the stem analysis. The two models are a site-specific allometric model of biomass, and a simplified conic model of volume. Additionally the conic model is decomposed into the three dimensions of growth along which variability exists (around the circumference, along the length of the stem, and height) to identify which dimension introduces the most error when no variability in that dimension is assumed. Relative error (RE) analysis and regression analysis show that stem analysis is superior in cases where few trees are used and accurate measures of wood increment are needed. At the population level, the allometric and conic models show different strengths. Allometric models are more accurate than the conic model (RE = -16% and -18%, respectively) and are better for carbon budgets, whereas the conic model was more precise than the allometric model (R² = 0.94 and 0.86, respectively; interquartile range = 24% and 41%, respectively) and maintains inter-annual variability, which is necessary in cross-validation efforts. Decomposition of the conic model supports previous findings that height is the second most important parameter, following diameter at breast height, in models of woody tissue growth. In Chapter 4, basal, crown and specific volume chronologies are compared to eddy covariance estimates of carbon dioxide flux between the forest and the atmosphere, including net ecosystem exchange, gross primary production and ecosystem respiration. At the University of Michigan Biological Station (UMBS), crown-grown tree-ring widths from P. grandidentata individuals are good recorders of the inter-annual variability of net ecosystem production. Coupled with other environmental information from UMBS, these records implicate defoliating insects as a previously under-appreciated modifier of stand level respiration and gross primary production. These histories of ring widths, volume and taper have unique potential to improve our understanding of how carbon is stored in and flows through forests within the terrestrial biosphere. In the face of global change, forests will experience new stressors, and changes in frequency of known stressors, that reduce the ability of trees to store carbon in woody tissues. A diversity of tree-ring-based chronologies can describe the sensitivity of carbon stores to these stressors, improving predictions of how forests respond to environmental changes.

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Österås, Ann Helén. "Interactions between calcium and heavy metals in Norway spruce : Accumulation and binding of metals in wood and bark". Doctoral thesis, Stockholm University, Department of Botany, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-81.

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Waste products from the forest industry are to be spread in forests in Sweden to counteract nutrient depletion due to whole tree harvesting. This may increase the bioavailability of calcium (Ca) and heavy metals, such as cadmium (Cd), copper (Cu) and zinc (Zn) in forest soils. Heavy metals, like Cd, have already been enriched in forest soils in Sweden, due to deposition of air pollutions, and acidification of forest soils has increased the bioavailability of toxic metals for plant uptake. Changes in the bioavailability of metals may be reflected in altered accumulation of Ca and heavy metals in forest trees, changes in tree growth, including wood formation, and altered tree species composition. This thesis aims at examining: A) if inter- or intra- specific differences in sensitivity to Cd occur in the most common tree species of Sweden, and if so, to study if these can be explained by the uptake and distribution of Cd within the plant: B) how elevated levels of Ca, Cd, Cu and Zn affect the accumulation and attachment of metals in bark and wood, and growth of young Norway spruce (Picea abies): C) how waste products from the forest industry, such as wood ash, influence the contents of Ca, Cd, Cu and Zn in wood and bark of young Norway spruce.

Sensitivity to Cd, and its uptake and distribution, in seedlings of Picea abies, Pinus sylvestris and Betula pendula from three regions (southern, central and northern parts) of Sweden, treated with varying concentrations of Cd, were compared. Differences in root sensitivity to Cd both among and within woody species were found and the differences could to some extent be explained by differences in uptake and translocation of Cd. The root sensitivity assays revealed that birch was the least, and spruce the most, sensitive species, both to the external and to tissue levels of Cd. The central ecotype of the species tested tended to be most Cd resistant.

The radial distribution, accumulation and attachment of, and interactions between Ca and heavy metals in stems of two-year-old Norway spruce trees treated with elevated levels of Cd, Cu, Zn and/or Ca, were investigated. Further, the influence of these metals on growth, and on root metal content, was examined. Accumulation of the metals was enhanced in wood, bark and/or roots at elevated levels of the metal in question. Even at low levels of the metals, similar to after application of wood ash, an enhanced accumulation was apparent in wood and/or bark, except for Cd. The increased accumulation of Zn and Cu in the stem did not affect the growth. However, Cu decreased the accumulation of Ca in wood. Higher levels of Cu and Cd reduced the stem diameter and the toxic effect was associated with a reduced Ca content in wood. Copper and Cd also decreased the accumulation of Zn in the stem. On the other hand, elevated levels of Ca increased the stem diameter and reduced the accumulation of Cd, Cu, Zn and Mn in wood and/or bark. When metals interacted with each other the firmly bound fraction of the metal reduced was in almost all cases not affected. As an exception, Cd decreased the firmly bound fraction of Zn in the stem.

The influence of pellets of wood ash (ash) or a mixture of wood ash and green liquor dregs (ash+GLD), in the amount of 3000 kg ha^-1, on the contents of Ca, Cd, Cu and Zn in wood and bark of young Norway spruce in the field was examined. The effect of the treatments on the metal content of bark and wood was larger after 3 years than after 6 years. Treatment with ash+GLD had less effect on the heavy metal content of bark and wood than treatment with ash alone. The ash treatment increased the Cu and Zn content in bark and wood, respectively, after 3 years, and decreased the Ca content of the wood after 6 years. The ash+GLD treatment increased the Ca content of the bark and decreased the Zn content of bark and wood after 3 years. Both treatments reduced, or tended to decrease, the Cd content in wood and bark at both times.

To conclude, small changes in the bioavailability of Ca, Cu, Cd and Zn in forest soils, such as after spreading pellets of wood ash or a mixture of wood ash and green liquor dregs from the forest industry, will be reflected in an altered accumulation of metals in wood and bark of Norway spruce. It will not only be reflected in changed accumulation of those metals in which bioavailability in the soil has been enhanced, but also of other metals, probably partly due to interactions between metals. When metals interact the exchangeable bound fraction of the metal reduced is suggested to be the main fraction affected. The small alterations in accumulation of metals should not affect the growth of Norway spruce, especially since the changes in accumulation of metals are low, and further since these decrease over time. However, as an exception, one positive and maybe persistent effect of the waste products is that these may decrease the accumulation of Cd in Norway spruce, which partly may be explained by competition with Ca for uptake, translocation and binding. A decreased accumulation of Cd in Norway spruce will probably affect the trees positively, since Norway spruce is one of the most sensitive species to Cd of the forest trees in Sweden. Thus, spreading of waste products from the forest industry may be a solution to decrease the accumulation of Cd in Norway spruce. In a longer perspective, this will decrease the risk of Cd altering the tree species composition of the forest ecosystem. An elevated bioavailability of Ca in forest soils will, in addition to Cd, probably also decrease the accumulation of other less competitive heavy metals, like Zn and Mn, in the stem.

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Adler, Anneli. "Accumulation of elements in Salix and other species used in vegetation filters with focus on wood fuel quality /". Uppsala : Dept. of Crop Production Ecology, Swedish University of Agricultural Sciences, 2007. http://epsilon.slu.se/200706.pdf.

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Österås, Ann Helén. "Interactions between calcium and heavy metals in Norway spruce : accumulation and binding of metals in wood and bark /". Stockholm : Botaniska institutionen, Univ, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-81.

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De, Cicco Pina Nicoletta [Verfasser] y Matthias [Akademischer Betreuer] Schöniger. "Experimental and numerical investigations on wood accumulation at bridge piers with different shapes / Pina Nicoletta De Cicco ; Betreuer: Matthias Schöniger". Braunschweig : Technische Universität Braunschweig, 2018. http://d-nb.info/1175816035/34.

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Philpott, Timothy James. "Translocation and accumulation of organic and inorganic nitrogen in wood resources colonized by the mycelial cord systems of the decay fungus Hypholoma fasciculare". Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42162.

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Translocation of nitrogen (N) through mycelial cords of wood decay fungi is thought to be the mechanism responsible for the observed increase in absolute N content in woody debris over time. This research evaluates the ability of the mycelial cords of the wood ¹⁵decay fungus Hypholoma fasciculare to translocate and accumulate labeled organic (¹⁵N-glycine, N Douglas-fir litter) and inorganic N (¹⁵NH₄⁺, ¹⁵NO₃⁻) in its wood substrate. Each N form was supplied separately to the growing fronts of mycelial cords established over 67 days from wood blocks (Douglas-fir) in soil microcosms. Three sampling occasions (days 6, 18 and 30 after N addition) were used to identify trends in ¹⁵N transfer and total N accumulation. Wood blocks inoculated with Hypholoma fasciculare assimilated significantly more ¹⁵N than uninoculated blocks for all ¹⁵N treatments on at least one sampling occasion. After 73 days of incubation (day 6 sampling occasion), inoculated wood blocks increased in absolute N content by 211% relative to uninoculated control blocks, but 80% of this accumulated N was lost after 97 days of incubation (day 30 sampling occasion). The small amount of ¹⁵N that was transferred contrasted with the large increase in total N, suggesting that the site of N transfer was largely from the soil underneath wood blocks rather than at the site of ¹⁵N injection. The precipitous decline in absolute N content was attributed to visible indications of mycelial senescence. This research demonstrates that the mycelial cords of Hypoloma fasciculare are capable of translocating ¹⁵N into a wood substrate and can also greatly increase the absolute N content of wood blocks. The results are discussed in the context of fungal ecology as well as woody debris management.

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Fors, Yvonne. "Sulfur-Related Conservation Concerns in Marine Archaeological Wood : The Origin, Speciation and Distribution of Accumulated Sulfur with Some Remedies for the Vasa". Doctoral thesis, Stockholm : Department of Physical, Inorganic and Structural Chemistry, Stockholm University, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-7627.

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Mazzochin, Marinez da Silva. "Indústria madeireira mundial e brasileira: o caso Paranaense". Universidade Estadual do Oeste do Parana, 2010. http://tede.unioeste.br:8080/tede/handle/tede/112.

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Made available in DSpace on 2017-05-12T14:42:40Z (GMT). No. of bitstreams: 1 Marinez Parte I.pdf: 5373100 bytes, checksum: b04e4763ea058d931916bf3ae4511ab3 (MD5) Previous issue date: 2010-09-08
This study seeks to understand the relationship of the process of capital accumulation in the wood processing industry and its relationship with the production of geographical space. The analysis of such a process takes into account the contradictions inherent in their development process. We seek to understand these contradictions, by pointing the main factors that encouraged the development of modern forestry, based on scientific research, especially in relation to raw material, meeting the industrial needs. It was intended in this work demonstrate the relationship between the various geographical scales as the focal point of socio-spatial training for the consolidation of the timber industry in the state of Parana.
O presente trabalho busca compreender a relação do processo de acumulação de capital no setor de transformação de madeira e sua relação com a produção do espaço geográfico. A análise de tal processo leva em consideração as contradições inerentes ao seu prodesso de desenvolvimento. Buscamos compreender essas contradições apontando os principais fatores que propiciam o desenvolvimento de uma moderna silvicultura, baseada em pesquisas científicas, sobretudo em relação à matéria-prima, atendendo as necessidades industriais. Pretendeu-se no decorrer do trabalho demonstrar a relação entre as diversas escalas geográficas como ponto central da formação sócio-espacial para a consolidação da indústria madeireira no Estado do Paraná.

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González, Alejandro Danilo Venegas. "Tree growth response to climate change in two threatened South American Biomes: Brazilian Atlantic Forest and Chilean Mediterranean Forest". Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/11/11150/tde-22032018-154156/.

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Biomes classified as Brazilian Atlantic Forest (BAF) and the Chilean Mediterranean forest (CMF) have been affected by anthropic pressure that has caused a considerable decrease of their forest surfasse. However, they are rich in biodiversity and they provide many ecosystem services and were, therefore, classified as \"hotspots\" (forests in risk). Therefore, is essential to study the natural dynamics and the climatic response of the trees of these forests to include conservation projects and strategic measures. To achieve these objectives, the scientific literature reports that tree growth rings are the only ecological indicators with annual resolution that can be efficient and highly accurate to obtain this information. In this context, the research project has as main objective the retrospective analysis of radial growth of forest species in different vegetation communities of BAF and CMF in response to climatic changes. To achieve this goal, four key questions were elaborated: 1) Which variable explains betterthe variability of radial growth at different spatial and temporal scales? 2) What is the growth resilience to recent climate changes? 3) Is there some more vulnerable population to expected climatic changes?. A total of five sites (seven populations) of Cedrela odorata and C. fissilis in BAF from the State of São Paulo in Brazil, and five sites (10 populations) of Nothofagus macrocarpa (FMC) from the central region of Chile were sampled, using a non-destructive method. Four chapters were developed to answer these questions. Chapter I seek to analyze the resilience in radial growth to changes in regional climate variability and droughts, in temporal and spatial scale, on Atlantic forest remnant forests of biogeographic region Serra do Mar. Results show that radial growth in wet sites (winter rains exceed 240 mm) depend on the moisture conditions in dry season, while the higher population is more sensitive to the favorable summer water condition, which would be explained because this population received a lower temperature than the other Cedrela spp. populations studied. Chapter II analyzed how recent climatic variability affected the radial growth in N. macrocarpa populations. It is observed that all the populations are closely linked to the precipitations of May-November (end of autumn/end of spring) and average temperature of October-December (mid-spring/early summer). In Chapter III, we continued exploring the growth responses to climate in the FMC populations in order to find biogeographic differences. In this sense, we evaluated if this significant decrease in tree growth is differentiated between populations and age classes, and determine if the positive effect of CO2 fertilization compensates the precipitation decrease and temperature increase in the last decades in the growth of older, maturer and younger trees . Results show a significant negative trend in all classes from the year 2000, which would be associated to a decrease in precipitation in all populations while temperature was more associated with the northern and southern populations (distribution limit). We did not find a positive effect of rising CO2. Finally, chapter IV integrated the results of the two biomes comparing the projections of aboveground trees biomass under two climatic scenarios of CMIP5 project (light and severe), in order to know which populations are more vulnerable to rising temperature forecasted by year 2100, using ring width data, wood density and allometric equations. This study will provide an overview of adaptation to recent and projected climatic changes of two hotspot neotropical biomes. Although they are different in structure-biodiversity-climate are in risk. Thus, we can understand the vulnerability of threatened forests in South America to global warming that, although they are in protected areas, does not guarantee their persistence.
Os biomas classificados como Mata Atlancia Brasileira (MAB) e da Floresta Mediterrânea Chilena (FMC) têm sido afetados pela pressão antrópica que tem causado uma diminuição considerável de sua superfície florestal. No entanto são ricas em biodiversidade e providenciam muitos serviços ecossistêmicos, pelo que foram classificadas como hotspot (florestas em risco). Portanto, é fundamental estudar a dinâmica natural e a resposta climática das árvores dessas florestas para incluir em projetos de conservação. Para atingir esses objetivos, a literatura científica reporta que os anéis de crescimento das árvores são os únicos indicadores ecológicos com resolução anual que podem ser eficientes e de elevada precisão para obter essas informações. Neste contexto, o projeto de pesquisa tem como objetivo geral a analise retrospectivo de crescimento radial de espécies florestais em diferentes comunidades vegetacionais da MAB e FMC em resposta às mudanças climaticas. Para atingir esse objetivo foram elaboradas quatro perguntas-chave: 1) Que variable explica melhor a variabilidade do crescimento radial a diferentes escalas espaciais e temporais? 2) Qual é a resiliência em crescimento das árvores às mudanças climáticas recentes? 3) Há alguma população mais vulnerável respeito às mudanças climaticas esperadas?. Foram coletadas amostras de lenho, através de método não destrutivo, de cinco sitios (sete populações) de Cedrela odorata e C. fissilis na MAB no estado de São Paulo em Brasil, e cinco sitios (10 populações) de Nothofagus macrocarpa na FMC na região central do Chile, para aplicação de tecnicas dendrocronologicas. Para responder essas questões foram desenvolvidos quatro capitulos. O capitulo I busca analisar a resiliência em crescimento radial às mudanças na variabilidade climática regional e secas, em escala temporal e espacial, em florestas remanentes da região biogeográfica Serra do Mar da Mata Atlântica, usando as especies bioindicadoras Cedrela fissilis and C. odorata. Os resultados mostram que o crescimento radial dos sítios mais úmidos (chuvas no inverno superam os 240 mm) dependem das condições hidricas da estação seca, enquanto que a população mais alta é mais sensível à condição hídrica favorável do verão, qual seria explicado porque essa população recebi uma menor temperatura respeito às outras populações de cedrela estudadas. No capitulo II analisou-se como a variabilidade climática recente estaria afeitando o crescimento radial in N. macrocarpa populations. Observa-se que todas as populações estão estreitamente ligadas às precipitações de Maio-Novembro (fim de outono/fim de primaveira) e temperatura média de Outubro-Dezembro (mediados de primaveira/inicios do verão). Especificamente, há uma tendencia negativa significativa no crescimento radial apartir de 1980 que esta associada a uma variação do clima regional. No capitulo III, continuo-se explorando as respostas do crescimento radial ao clima nas populações da FMC com objetivo de encontrar diferencias biogeográficas. Neste sentido, foi avaliado se essa diminuição significativa de crescimento é diferenciada entre populações e classes de idade, e analisar se o efeito positivo da fertilização de CO2 compensa a diminuição da precipitação e aumento da temperatura nas ultimas decadas no crescimento de árvores velhos, maduros e jovens. Os resultados mostram uma tendencia negativa significativa em todas as clases apartir do ano 2000, qual estaria associada a diminuição da precipitação em todas as populações enquanto a temperatura teve mais associada às populações do sul. Não foi encontrado um efeito positivo do aumento de CO2. Finalmente, o capitulo IV integrou os resultados dos dois biomas comparando as proyeções de biomasa arborea sob dois escenarios climáticos do projeto CMIP5 (leve e severo), com objetivo de conocer quais populações são mais vulneraveis ao aumento da temperature previsto para o ano 2100, usando crescimento radial, densidade de madeira e ecuações alométricas. Os resultados mostram que a população com maior influencia urbana e a mais seca são as mais vulneráveis ao aumento exarcerbado de temperatura nas regiões de MAB and FMC, respectivamente. O presente estudo permitiu-nos apresentar uma visão da adaptação às mudanças climáticas recentes e projetadas de dois biomas hotspot. Embora sejam diferentes em estrutura-biodiversidade-clima estão em risco. Assim, podemos entender a vulnerabilidade de florestas neotropicais ao aquecimento global, embora estejam em áreas protegidas, não garante sua persistência.

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Libros sobre el tema "Wood accumulation"

Murphy, J. Damage accumulation in wood structural members under stochastic live loads. [Madison, Wis.?: U.S. Forest Service, 1987.

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Williams, R. Sam. Accumulation of sulfur compounds at the interface of paint and wood following exposure to sulfurous acid. [Washington, D.C.?: U.S. Dept. of Agriculture, 1989.

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Parrott, Joanne Louise. Accumulation of fish mixed function oxygenase inducers by semipermeable membrane devices in river water and effluents, Athabasca, Peace and Wapiti rivers, August and September, 1995. Edmonton: The Study, 1996.

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Damage accumulation in wood structural members under stochastic live loads. [Madison, Wis.?: U.S. Forest Service, 1992.

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Accumulation of fish mixed function oxygenase inducers by semipermeable membrane devices in river water and effluents, Athabasca River, August and September, 1994. Edmonton, Alta: Northern River Basins Study, 1996.

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Thoreau, Henry David. Walden. Editado por Stephen Allen Fender. Oxford University Press, 2008. http://dx.doi.org/10.1093/owc/9780199538065.001.0001.

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‘The mass of men lead lives of quiet desperation.’ In 1845 Henry David Thoreau left his home town of Concord, Massachusetts to begin a new life alone, in a rough hut he built himself a mile and a half away on the north-west shore of Walden Pond. Walden is Thoreau’s classic autobiographical account of this experiment in solitary living, his refusal to play by the rules of hard work and the accumulation of wealth and above all the freedom it gave him to adapt his living to the natural world around him. This new edition of Walden traces the sources of Thoreau’s reading and thinking and considers the author in the context of his birthplace and his sense of its history - social, economic and natural. In addition, an ecological appendix provides modern identifications of the myriad plants and animals to which Thoreau gave increasingly close attention as he became acclimatized to his life in the woods by Walden Pond.

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Mattissen, Johanna. Sub-Types of Polysynthesis. Editado por Michael Fortescue, Marianne Mithun y Nicholas Evans. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780199683208.013.5.

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The structural heterogeneity of polysynthetic languages is captured by a sublassification of allegedly polysynthetic languages according to their word-formational type (number of roots allowed in a verb form), namely, compositional, transitional, or affixal, and their internal organization (template vs. scope or both). Further parameters show correlations to these independent ones: the number of participants encoded on a verb, the imaginable evolutionary path via which the structure has come about, namely layering (“onion type”), internal expansion (“sandwich type”) or coalescence (“burdock type”), and the characteristic design of a complex verb form: Grammatical category accumulation (integration of non-obligatory, rather grammatical information); ping-pong recategorization (multiple verbalization and nominalization); productive in/excorporation; dependent-head synthesis; multiple packing (integration of rather lexical information); holophrasis (all wordforms being predicates—or particles); composite-stem layout (composite root-like morphemes, unitary concept); and building-block design (multiple classifer-like morphemes make up a wordform). The classification along these parameters reconciles conflicting approaches to polysynthesis.

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Capítulos de libros sobre el tema "Wood accumulation"

Kirby, K. J. "Accumulation of dead wood — a missing ingredient in coppicing?" En Ecology and Management of Coppice Woodlands, 99–112. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-2362-4_6.

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Queirolo, F., P. Valenta, S. Stegen y S. W. Breckle. "Accumulation of Heavy Metals in Oak Wood from Polluted Regions". En Mechanisms and Effects of Pollutant-Transfer into Forests, 193–202. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-009-1023-2_22.

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Grigillo, Dejan, Anja Vrečko, Matjaž Mikoš, Tomaž Gvozdanović, Andreja Anžur, Rok Vezočnik y Dušan Petrovič. "Determination of Large Wood Accumulation in a Steep Forested Torrent Using Laser Scanning". En Engineering Geology for Society and Territory - Volume 3, 127–30. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-09054-2_24.

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Vizzarri, Matteo, Roberto Pilli, Anu Korosuo, Ludovico Frate y Giacomo Grassi. "The Role of Forests in Climate Change Mitigation: The EU Context". En Climate-Smart Forestry in Mountain Regions, 507–20. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-80767-2_15.

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AbstractThe European Union (EU) aims at reaching carbon neutrality by 2050. Within the land use, land-use change, and forestry (LULUCF) sector, forestry will contribute to this target with CO2 sink, harvested wood products (HWP), and use of wood for material or energy substitution. Despite the fact that the forest sink currently offsets about 9% of the total EU GHG emissions, evaluating its future mitigation potential is challenging because of the complex interactions between human and natural impacts on forest growth and carbon accumulation. The Regulation (EU) 2018/841 has improved robustness, accuracy, and credibility of the accounting of GHG emissions and removals in the LULUCF sector. For the forest sector, the accounting is based on the Forest Reference Level (FRL), i.e., a projected country-specific value of GHG emissions and removals against which the actual GHG emissions and removals will be compared. The resulting difference will count toward the EU GHG target for the period 2021–2030. Here, we provide an overview of the contribution of forests and HWP to the EU carbon sink for the period 2021–2025 (proposed FRLs) and focus on the contribution of mountain forests to the EU carbon sink, through exploring co-benefits and adverse side effects between climate regulation and other ecosystem services.

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Carnacina, Iacopo, Aleksandra Lescova y Stefano Pagliara. "A Methodology to Measure Flow Fields at Bridge Piers in the Presence of Large Wood Debris Accumulation Using Acoustic Doppler Velocimeters". En Lecture Notes in Civil Engineering, 17–25. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-8181-2_2.

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Yang, Yating, Xiaoli Wu y Wei Liu. "Scar Symptom: Erythema and Thickness". En Textbook on Scar Management, 103–8. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-44766-3_11.

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AbstractErythema is a word derived from the Greek erythros, which describes red color of the skin or mucous membrane. In particular, erythema and redness in scar are important as they are closely related to scar symptoms and tissue maturation, and thus can serve as an indicator for scar prognosis. There is rich information in the literature regarding its clinical manifestation, pathological mechanism, and its relation to inflammation and symptoms of pain and itching as well as the clinical treatment. Scar thickness reflects the accumulation of collagen content and there is no necessary association between scar redness and thickness. This chapter mainly focuses on the overview of scar erythema/redness in the aspects of definition, possible mechanism related to clinical manifestation and symptoms, and finally the therapeutic options.

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Nightingale, Stephen y Hideki Tanaka. "The Word Is Mightier than the Count: Accumulating Translation Resources from Parsed Parallel Corpora". En Computational Linguistics and Intelligent Text Processing, 420–31. Berlin, Heidelberg: Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/3-540-36456-0_45.

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Zolotova, Ekaterina Sergeevna. "Study of the Various Aspects of Mineral Nutrition, Accumulation and Distribution of Micro- and Macro-Elements in Woody Plants". En Experimental Ecophysiology and Biochemistry of Trees and Shrubs, 133–37. Includes bibliographical references and index.: Apple Academic Press, 2020. http://dx.doi.org/10.1201/9780429322266-23.

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Rahul, Jitin. "Stone Crusher Dust and Its Impact: Accumulation Efficiency of Some Woody Tree Species Around the Stone Crusher Plant (SCP)". En Sustainable Energy-Water-Environment Nexus in Deserts, 621–27. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-76081-6_78.

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Actas de conferencias sobre el tema "Wood accumulation"

Wyss, Andris, Isabella Schalko y Volker Weitbrecht. "Field test on large wood accumulation at a bridge pier". En Proceedings of the 39th IAHR World Congress From Snow to Sea. Spain: International Association for Hydro-Environment Engineering and Research (IAHR), 2022. http://dx.doi.org/10.3850/iahr-39wc252171192022106.

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De, P., E. Paris y L. Solari. "Wood accumulation at bridges: Laboratory experiments on the effect of pier shape". En The International Conference On Fluvial Hydraulics (River Flow 2016). Taylor & Francis Group, 6000 Broken Sound Parkway NW, Suite 300, Boca Raton, FL 33487-2742: CRC Press, 2016. http://dx.doi.org/10.1201/9781315644479-363.

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Stocker, Barbara, Adriano Lais, Isabella Schalko y Robert M. Boes. "Backwater Rise Due To Large Wood Accumulation At Protruding Piers Of Dam Spillways". En Proceedings of the 39th IAHR World Congress From Snow to Sea. Spain: International Association for Hydro-Environment Engineering and Research (IAHR), 2022. http://dx.doi.org/10.3850/iahr-39wc252171192022698.

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Tarita, Anatolie y Valeriu Brasoveanu. "Bioacumularea metalelor grele în lemnul speciilor de arbori din ecosistemul forestier „Padurea Hânceşti”". En Impactul antropic asupra calitatii mediului. Institute of Ecology and Geography, Republic of Moldova, 2019. http://dx.doi.org/10.53380/9789975330800.11.

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The total content of heavy metals (As, Cd, Co, Cr, Cu, Fe, Ni, Pb, Zn) in the wood of different species of trees in the forest ecosystem "Forest Hânceşti" was determined. The contents of HM in different wood species (strong/soft) trees were different. Bioaccumulation Factor (BCF) of HM for different tree species differ greatly from species to species and ecosystem. Analyzed wood tree species have been bioaccumulated HM in the following order: Zn>Cu>Ni>Cd>Pb>Cr>Co>As. Mobility Factor (MF), evaluated in order to estimate accumulation of HM in the wood of the trees studied from atmospheric air through the leaf material, with the exception of Pb is >1, indicating polluted air as a major source of impairment of studded forestry species.

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Maaroufi, Maroua, Kamilia Abahri, Alexandra Bourdot y Chady El Hachem. "3D Modelling of Hydric Transfers in Spruce Wood with Consideration of Sorption Hysteresis". En 4th International Conference on Bio-Based Building Materials. Switzerland: Trans Tech Publications Ltd, 2022. http://dx.doi.org/10.4028/www.scientific.net/cta.1.743.

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Buildings are responsible for a large portion of the total energy consumption, and have a heavy environmental impact. Wood is one of the most used bio-based building materials, as it helps reducing the environmental footprint of the construction sector. Spruce wood is widely available in France and therefore massively used in buildings. It has interesting thermal and acoustic insulation performances and a good hydric regulation property. Spruce wood microstructure is highly heterogeneous and multiphasic, which makes it harder to apprehend. On the other hand, sorption hysteresis phenomenon is responsible for the moisture accumulation in porous building materials. It is often neglected in hygrothermal transfers modelling, which leads to incorrect water content values. The aim of this work is to investigate the influence of the sorption hysteresis phenomenon on the hydric transfers of spruce wood. The heterogeneity of the microstructure is also considered through 3D tomographic reconstructions included in the modelling.

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Olson, Vickie G. "Reducing Cooling Tower Fill Fouling and Degradation With Water Quality Control". En ASME 2007 Power Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/power2007-22052.

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Cooling tower fill may be composed of wood or plastic, but it must provide adequate surface area for heat dissipation. Online and field water quality analysis can maximize tower efficiency and minimize maintenance. Uncontrolled levels of pH, bio-growth, or over-application of chemicals cause degradation of the material and plugging. Automatic control of pH conditioner can be accomplished with proven differential pH methods tied to analog and/or digital control. Oxidizing biocide application can be optimized with ORP and halogen analysis and control. Overuse of this type of biocide can also cause wood delignification that can affect the structural integrity of the tower. Another cause of fouling is excessive solids accumulation. Solids buildup can be minimized with side-stream filtration and/or clarification and monitored with low maintenance self-cleaning optical probes.

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Dudel, Ernst Gert, Carsten Brackhage, Claudia Clemens, Holger Dienemann, Martin Mkandawire, Joachim Rotsche y Arndt Weiske. "Principles and Limitations for Natural Attenuation of Radionuclides in Former Uranium Mining and Milling Sites". En ASME 2001 8th International Conference on Radioactive Waste Management and Environmental Remediation. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/icem2001-1260.

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Abstract Development of a self-sustainable remediation process seems to require an approach that uses the entire ecosystem functions. Selected effects have been documented in four case studies both in forests and wetlands: I) In the course of vegetation and soil development on experimental plots forested since 1963, concentration of RNs was reduced from >1000 Bq/kg to <200 Bq/kg in the top soil due to dilution by accumulation of organic carbon; II) in the stem wood of spruce and alder as few as 13–54 mg U/ha had been fixed; III) wetland compartments acted as strong sinks (> 1000 Bq/kg in organic matter); IV) water quality below a natural wetland — working as a filter within an uranium mineralisation hot spot in Malawi (SE-Africa) (> 2000 Bq/kg soil) — demonstrated no difference to a reference brook within the catchment.

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"A Study on Sustainable Reutilization of C&D Debris in the Construction of Traffic Barrier". En Recent Advancements in Geotechnical Engineering. Materials Research Forum LLC, 2021. http://dx.doi.org/10.21741/9781644901618-14.

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Abstract. In India, the construction industry is growing at twice the world average. This leads to a significant accumulation of C&D waste. This typically includes asphalt, steel, concrete, bricks, wood and other building materials. It is estimated on a conservative basis that over 25-30 million tons of C&D waste is generated which clogs rivers, blocks traffic and occupies land / agricultural space which in turn creates pollution, solid waste production, discharge of dust and gas and leads to additional utilization of natural resources including non-renewable resources, thereby depleting the available resources. Only little amount of construction and demolition concrete debris is recycled or reused. Construction and demolition waste generation and handling issues are being focused to achieve sustainable goals. Based on this study, experimental investigations are carried out to evaluate the material properties and to study the strength characteristics and effect of partial replacement (20 %, 30 % and 40 %) of both fine and coarse aggregate obtained from construction and demolition waste (CDW) in the construction of intermediate road traffic concrete barriers.

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Al Teneiji, Shamma Saleh y Sherooq Saleh Al Teneiji. "Electrostatic Dust Removal for Solar Panels". En ADIPEC. SPE, 2022. http://dx.doi.org/10.2118/210820-ms.

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Abstract The world is evolving and developing in various sectors to enhance life which in return is increasing the energy requirements. The development of sustainable energy sources has increased over the years in order to preserve the fossil fuel energy resources such as coal, oil, natural gas, wood etc. which will reduce greenhouse gas emissions and accordingly protect the environment. As the world moves toward sustainable solutions of clean energy resources for a more environmentally friendly life, the utilization of solar energy has increased. Subsequently, Photovoltaics (PV) panels usage increased tremendously in the recent years. the high efficiency of the PVs is highly impacted by the dust build up causing a big decrease of output power in power output which could reach up to 50% power loss with dust accumulation of 5 mg/cm2 as it be discussed later in paper. The objective of this paper is to present one of the proposed solutions for cleaning the solar panels and as a result enhance the absorption of solar power and the efficiency of the PV panels. The solution is a waterless approach for dust removal from solar panels using electrostatic induction. This is a new technology which is experimentally tested. The new technology is a development to Electrodynamic Screens (EDS) technology where particles are electrically conducted actively charged like conductive iron particles where particle lift-off happens when the applied voltage reaches a threshold value that enables particles to overcome the force that adhere them on the surface. Implementing this technology shall provide a sustainable solution that can be implemented anywhere specially areas where it is difficult to transport water or visit regularly for cleaning. The technology is still in experimental stages not established or implemented in any existing system. Results are based on theoretical calculation, experimental lab prototype, and conclusions.

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Panici, Diego y Gustavo de Almeida. "The Influence Of Pier Shape On The Accumulations Of Large Wood Debris". En Proceedings of the 39th IAHR World Congress From Snow to Sea. Spain: International Association for Hydro-Environment Engineering and Research (IAHR), 2022. http://dx.doi.org/10.3850/iahr-39wc252171192022243.

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Informes sobre el tema "Wood accumulation"

Burch, D. M. y W. C. Thomas. An analysis of moisture accumulation in a wood frame wall subjected to winter climate. Gaithersburg, MD: National Institute of Standards and Technology, 1991. http://dx.doi.org/10.6028/nist.ir.4674.

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Wooster, John y Sue Hilton. Large woody debris volumes and accumulation rates in cleaned streams in redwood forest in southern Humboldt County, California. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station, 2004. http://dx.doi.org/10.2737/psw-rn-426.

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Harris, Kathleen y Christopher Haring. Tar-Pamlico and Neuse River Basins, North Carolina, geomorphic summary report. Engineer Research and Development Center (U.S.), junio de 2022. http://dx.doi.org/10.21079/11681/44600.

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The Tar-Pamlico and Neuse River Basins are neighboring basins in eastern North Carolina, both originating in the piedmont physiographic region, transitioning to coastal plains, and emptying into Pamlico Sound. The Pittsburgh District is responsible for the continued efforts to assist local sponsors with managing these basins and submitted a Water Operations Technical Support (WOTS) request. The WOTS program, funded by Headquarters, US Army Corps of Engineers, provides funding for the Coastal and Hydraulics Laboratory (CHL) to provide technical assistance to develop innovative solutions to water resource problems. The objectives of this study are to identify flood risk management alternatives to address the accumulation of woody debris in the channel systems. CHL compiled existing conditions information and researched current and potential new methods for managing woody debris to provide a comprehensive list of recommendations. The results and recommendations are provided in this document.

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Backstrom, Robert y David Dini. Firefighter Safety and Photovoltaic Systems Summary. UL Firefighter Safety Research Institute, noviembre de 2011. http://dx.doi.org/10.54206/102376/kylj9621.

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Under the United States Department of Homeland Security (DHS) Assistance to Firefighter Grant Fire Prevention and Safety Research Program, Underwriters Laboratories examined fire service concerns of photovoltaic (PV) systems. These concerns include firefighter vulnerability to electrical and casualty hazards when mitigating a fire involving photovoltaic (PV) modules systems. The need for this project is significant acknowledging the increasing use of photovoltaic systems, growing at a rate of 30% annually. As a result of greater utilization, traditional firefighter tactics for suppression, ventilation and overhaul have been complicated, leaving firefighters vulnerable to potentially unrecognized exposure. Though the electrical and fire hazards associated with electrical generation and distribution systems is well known, PV systems present unique safety considerations. A very limited body of knowledge and insufficient data exists to understand the risks to the extent that the fire service has been unable to develop safety solutions and respond in a safe manner. This fire research project developed the empirical data that is needed to quantify the hazards associated with PV installations. This data provides the foundation to modify current or develop new firefighting practices to reduce firefighter death and injury. A functioning PV array was constructed at Underwriters Laboratories in Northbrook, IL to serve as a test fixture. The main test array consisted of 26 PV framed modules rated 230 W each (5980 W total rated power). Multiple experiments were conducted to investigate the efficacy of power isolation techniques and the potential hazard from contact of typical firefighter tools with live electrical PV components. Existing fire test fixtures located at the Delaware County Emergency Services Training Center were modified to construct full scale representations of roof mounted PV systems. PV arrays were mounted above Class A roofs supported by wood trusses. Two series of experiments were conducted. The first series represented a room of content fire, extending into the attic space, breaching the roof and resulting in structural collapse. Three PV technologies were subjected to this fire condition – rack mounted metal framed, glass on polymer modules, building integrated PV shingles, and a flexible laminate attached to a standing metal seam roof. A second series of experiments was conducted on the metal frame technology. These experiments represented two fire scenarios, a room of content fire venting from a window and the ignition of debris accumulation under the array. The results of these experiments provide a technical basis for the fire service to examine their equipment, tactics, standard operating procedures and training content. Several tactical considerations were developed utilizing the data from the experiments to provide specific examples of potential electrical shock hazard from PV installations during and after a fire event.

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Backstrom, Robert y David Backstrom. Firefighter Safety and Photovoltaic Installations Research Project. UL Firefighter Safety Research Institute, noviembre de 2011. http://dx.doi.org/10.54206/102376/viyv4379.

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Sengupta-Gopalan, Champa, Shmuel Galili y Rachel Amir. Improving Methionine Content in Transgenic Forage Legumes. United States Department of Agriculture, febrero de 2001. http://dx.doi.org/10.32747/2001.7580671.bard.

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Leguminous forage crops are high in proteins but deficient in S- amino acids. It has been shown that both wool quality and milk production can be limited by the post-ruminal supply of sulfur-containing amino acids. Efforts to use conventional plant breeding and cell selection techniques to increase the S-amino acid content of alfalfa have met with little success. With the objective to increase the S-amino acid content of forage legumes, the goal of this project was to co- express the methionine rich zein genes from corn along with a gene for a key enzyme in methionine biosynthesis, aspartate kinase(AK). The zeins are seed storage proteins from corn and are groupec into four distinct classes based on their amino acid sequence homologies. The b-zein (15kd) and the 6zein (10kD and 18kD) have proportionately high levels of methionine (10%, 22% and 28%, respectively). Initial studies from our lab had shown that while the 15kD zein accumulated to high levels in vegetative tissues of transgenic tobacco the l0kD zein did not. However, co-expression of the 10kD zein with the 15kD zein genes in tobacco showed stabilization of the 10kD zein and the co-localization of the 10kD and 15kD zein proteins in unique ER derived protein bodies. AK is the key enzyme for producing carbon skeletons for all amino acids of the aspartate family including methionine. It is, however, regulated by end-product feedback inhibition. The specific objectives of this proposal were: i. to co-express the 15kD zein with the 10/18kD zein genes in alfalfa in order to enhance the level of accumulation of the 10/18kD zein; ii. to increase methionine pools by expressing a feedback insensitive AK gene in transformants co-expressing the 15kD and 10/18kD zein genes. The Israeli partners were successful in expressing the AK gene in alfalfa which resulted in an increase in free and bound threonine but not in methionine (Galili et al., 2000). Since our target was to increase methionine pools, we changed our second objective to replace the AK gene with the gene for cystathionine gamma synthase (CGS) in the co-expression studies. The first methionine specific reaction is catalyzed by CGS. An additional objective was to develop a transformation system for Berseem clover, and to introduce the appropriate gene constructs into it with the goal of improving their methionine content. Genes for the 15kD zein along with the genes for either the 10kD or 18kD zein have been introduced into the same alfalfa plant both by sexual crosses and by re-transformation. Analysis of these zein co-expressors have shown that both the IOkD and 18kD zein levels go up 5 to 10 fold when co-expressed with the 15kD zein (Bagga et al., MS in preparation). Incubation of the leaves of transgenic alfalfa co-expressing the 15kD and 10kD zein genes, in the rumen of cows have shown that the zein proteins are stable in the rumen. To increase the level of zein accumulation in transgenic alfalfa different promoters have been used to drive the zein genes in alfalfa and we have concluded that the CaMV 35S promoter is superior to the other strong leaf -specific promoters. By feeding callus tissue of alfalfa plants co-expressing the 15kD and 10kD zein genes with methionine and its precursors, we have shown that the zein levels could be significantly enhanced by increasing the methionine pools. We have now introduced the CGS gene (from Arabidopsis; kindly provided to us by Dr. Leustek), into the 15kD zein transformants and experiments are in progress to check if the expression of the CGS gene indeed increases the level of zein accumulation in alfalfa. We were not successful in developing a transformation protocol for Berseem clover.

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Cahaner, Avigdor, Sacit F. Bilgili, Orna Halevy, Roger J. Lien y Kellye S. Joiner. effects of enhanced hypertrophy, reduced oxygen supply and heat load on breast meat yield and quality in broilers. United States Department of Agriculture, noviembre de 2014. http://dx.doi.org/10.32747/2014.7699855.bard.

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Original objectivesThe objectives of this project were to evaluate the growth performance, meat yield and quality attributes of broiler strains widely differing in their genetic potential under normal temperature vs. warm temperature (short and long-term) conditions. Strain differences in breast muscle accretion rate, metabolic responses under heat load and, gross and histopathological changes in breast muscle under thermal load was also to be characterized. BackgroundTremendous genetic progress has been made in broiler chicken growth rate and meat yield since the 1950s. Higher growth rate is driven by higher rates of feed intake and metabolism, resulting in elevated internal heat production. Hot rearing conditions negatively affect broiler growth by hindering dissipation of heat and may lead to a lethal elevation in body temperature. To avoid heat-induced mortality, broilers reduce feed intake, leading to depressed growth rate, lower weight gain, reduce breast meat yield and quality. Thus, the genetic potential of contemporary commercial broilers (CCB) is not fully expressed under hot conditions. Major conclusions, solutions, and achievementsResearch conducted in Israel focused on three broiler strains – CCB, Featherless, Feathered sibs (i.e., sharing similar genetic background). Complimentary research trials conducted at Auburn utilized CCB (Cobb 500, Cobb 700, Ross 308, Ross 708), contrasting their performance to slow growing strains. Warm rearing conditions consistently reduced feed intake, growth rate, feed efficiency, body weight uniformity and breast muscle yield, especially pronounced with CCB and magnified with age. Breast meat quality was also negatively affected, as measured by higher drip loss and paler meat color. Exposure to continuous or short-term heat stress induced respiratory alkalosis. Breast muscle histomorphometrics confirmed enhanced myofiber hypertrophy in CCB. Featherless broilers exhibited a significant increase in blood-vessel density under warm conditions. Rapid growth and muscle accretion rate was correlated to various myopathies (white striping, woody and necrotic) as well as to increases in plasma creatinekinase levels. Whether the trigger(s) of muscle damage is loss of cellular membrane integrity due to oxidative damage or tissue lactate accumulation, or to loss of inter-compartmental cation homeostasis is yet to be determined. Based on genome-wide single-nucleotide polymorphism array genotyping, identification of the gene with the recessive mutation Scaleless (sc) facilitated the development a dCAPS assay to discriminate between sc carrier (sc/+) and non-carrier (+/+) individuals. ImplicationsThis project confirmed that featherless broiler strains grow efficiently with high yield and quality of breast meat, even under warm rearing conditions that significantly depress the overall performance of CCB. Therefore, broiler meat production in hot regions and climates can be substantially improved by introducing the featherless gene into contemporary commercial broiler stocks. This approach has become more feasible with the development of dCAPS assay. A novel modification of the PCR protocol (using whole blood samples instead of extracted DNA) may contribute to the efficient development of commercial featherless broiler strains. Such strains will allow expansion of the broiler meat production in developing countries in warm climates, where energy intensive environmental control of rearing facilities are not economical and easily achievable.

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