Academic literature on the topic 'Tree pits'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Tree pits.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Tree pits"
1
Strom, Steven. "Tree pits as urban gardens." Landscape Research 15, no. 2 (June 1990): 19–22. http://dx.doi.org/10.1080/01426399008706311.
Full text
2
Webb, Sara L. "Windstorm damage and microsite colonization in two Minnesota forests." Canadian Journal of Forest Research 18, no. 9 (September 1, 1988): 1186–95. http://dx.doi.org/10.1139/x88-182.
Full textAbstract:
Scattered trees were uprooted, snapped, or bent during a 1983 windstorm in two northwestern Minnesota pine forests. I tested potential correlates (tree species, tree size, cause of damage) of damage type, and compared consequences of the uprooting, snapping, and bending of trees by assessing postdamage survival and by surveying formation and colonization of microsites (mounds, pits, stumps, and dead boles). Larger trees damaged directly by wind were usually snapped and killed in both study areas, regardless of tree species. Smaller trees damaged by falling neighbors were either (i) bent without sustaining mortality or forming microsites, a damage type prevalent among strong-wooded Acersaccharum and Ostryavirginiana in a Pinus–Acer study area, or (ii) uprooted, forming small mounds and pits, a damage type prevalent among weakwooded Abiesbalsamea and Picea spp. in a Pinus–Abies study area. Bent trees usually survived, at least for several years. However, uprooted and snapped trees were equally unlikely to survive their damage. Thus, uprooting and snapping were equally likely to result in dead bole formation. Windstorm-related microsites covered small proportions (6 and 18%) of the floor of the two forests, most as dead boles rather than as stumps, mounds, or pits. Microsites from uprooting, microsites from snapping, and background substrates did not differ in colonizing tree flora but did differ in density of colonists. The role of microsites varied with the autecology of tree species present. In the Pinus–Abies area, rotting wood of stumps and boles was the major establishment substrate for all regenerating tree species. In the Pinus–Acer area, Acersaccharum and A. rubrum were numerically dominant over other species on all substrates, with seedling densities highest away from microsites. Observed patterns of survival and tree regeneration indicate that uprooting and snapping of trees do not differ strongly in their consequences for either forest.
3
Moya Roque, Róger, Mario Tomazelo Fo, and Edwin Canessa Amador. "Fiber morphology in fast growth Gmelina arborea plantations." Madera y Bosques 13, no. 2 (August 30, 2016): 3–13. http://dx.doi.org/10.21829/myb.2007.1321225.
Full textAbstract:
Gmelina arborea is planted in large areas of forest with the objective of producing solid wood using well known silvicultural techniques and taking advantage of the properties of the wood quality of fast-growing tree species managed in short rotation systems. The aim of this study was to analyze the morphology and dimension of fibers from the pith to the bark in trees from fast growth plantations in northern Costa Rica.The results indicate that fiber morphology is irregular in both diameter and shape; with 1 to 4 septa, abundant crystals deposited in fiber lumina and minutely bordered pits with oblique and nonvestured apertures. Fiber length, width and cell wall thickness increased with tree age in the early stages. Lumen diameter was not correlated with tree age.
4
Hassanpoor Tichi, Ali, Habibollah Khademieslam, and Mojtaba Rezanezhad Divkolae. "Evaluation of physical, anatomical, and biometric characteristics of Citrus sinensis trees in longitudinal and transverse axes of stem." BioResources 15, no. 3 (June 3, 2020): 5696–709. http://dx.doi.org/10.15376/biores.15.3.5696-5709.
Full textAbstract:
Three healthy Citrus sinensis (orange) trees in Babol, Iran, were randomly selected and cut. Two discs of 5 cm thickness were prepared along the tree (breast height and crown). In the transverse direction, the test specimens were cut 2 × 2 cm to 3 cm from the pith to the bark sequentially and examined. The biometric and physical properties were measured, and microscopic sections of wood near the bark were studied using light microscopy according to the International Association of Wood Anatomists’ (IAWA) List. Anatomical examination of the C. sinensis wood showed that the species was a diffuse porous hardwood, with indistinct growth rings, simple perforation plates, alternate intervessel pits, and banded parenchyma. The basic density and oven-dry density increased from the pith towards the tree bark and from the bottom of the tree towards the crown. There was a significant difference in both the transverse and longitudinal directions of the C. sinensis tree in terms of fiber length, fiber lumen diameter, fiber diameter, and cell wall thickness. The mean fiber length, fiber diameter, fiber lumen diameter, and cell wall thickness were 0.76 mm, 23.64 µm, 9.23 µm, and 14.41 µm, respectively.
5
Beatty, Susan W., and Earl L. Stone. "The variety of soil microsites created by tree falls." Canadian Journal of Forest Research 16, no. 3 (June 1, 1986): 539–48. http://dx.doi.org/10.1139/x86-094.
Full textAbstract:
The uprooting of forest trees leads to the formation of microsites on the forest floor, contributing to fine-scale heterogeneity in soil properties. We found the types of microsites formed depended on the way the tree fall occurred. Tree falls were classified as either hinge or rotational types. Hinge tree falls formed when the root mat of a tree and the surrounding soil were uplifted vertically, leaving an adjacent pit in the soil. Hinge tree falls varied as to thickness of the root mat and angle of uplift. Rotational tree falls were usually a result of a ball and socket motion of the root mat and soil, which positioned the tree bole over the newly created pit. The tree falls disrupted and redistributed surface soil organic matter and subsoil. In rotational tree falls, the surface material remained intact, covering some of the pit and the adjacent side of the mound. In hinge tree falls, the surface organic matter was deposited on the throw side of the mound, leaving subsoil on the other side and in the pit. With time, however, hinge-type pits accumulated litter and eventually had more organic matter than mounds. Old mounds from both hinge and rotational tree falls had lower concentrations of calcium and magnesium, lower pH, and less moisture than pits. The tree fall process creates long-term soil patterns and maintains microsite heterogeneity in forest communities.
6
Hassanpoor Tichi, Ali, Hadi Gholamiyan, and Mojtaba Rezanezhad Divkolae. "Changes in biometric, density, and microscopic features of Parrotia persica trees in longitudinal and radial directions of the stem." BioResources 16, no. 2 (March 26, 2021): 3563–74. http://dx.doi.org/10.15376/biores.16.2.3563-3574.
Full textAbstract:
The biometric, density, and microscopic features of Parrotia persica species were investigated in this work. Three completely healthy P. persica trees were randomly felled. Three discs of 5 cm thickness were cut at three height levels (at breast height, 3 m, and 4.5 m) of each stem. The test specimens were sequentially taken from pith to bark. The biometric characteristics of the fiber and their density were analyzed. The microscopic features were studied according to the IAWA List of Hardwoods. It was found that all biometric factors of P. persica were decreased with increasing tree height from base to top. In contrast, these factors were also increased with the increase of distance from the pith toward the bark. Oven-dry density and basic density were decreased with an increase in the height along the tree stem. However, in the transverse direction, oven-dry density and basic density were increased from pith to bark. The anatomical study indicated that P. persica is a diffuse-porous hardwood that has distinct growth ring boundaries, heterogeneous rays, scalariform perforation, and alternative intervessel pits.
7
Yoshida, Toshiya. "Regeneration Dynamics on Treefall Mounds and Pits for 10 Years after a Windfall in a Natural Mixed Forest." Forests 12, no. 8 (August 10, 2021): 1064. http://dx.doi.org/10.3390/f12081064.
Full textAbstract:
The treefall mounds and pits resulting from uprooting caused by strong winds is an indispensable microtopography for the regeneration of many tree species through improved light conditions and mineral soil exposure. These microtopographies are expected to become more important because global warming is predicted to increase windstorm frequency. This study aimed to clarify the characteristics of mounds and pits that contribute to the early establishment of major tree species in a natural mixed forest of northern Japan. The 39 tip-up mounds caused simultaneously by a strong typhoon in September 2004 were selected. In 2006, light intensity and soil moisture contents were measured in each mound and pit. Seedlings of all tree species were counted, and in 2014, the height of saplings was measured. The initial seedling density, regardless of tree species, was significantly higher in the pits than on the mound, but the density at the 10-th growing season decreased significantly in the pits and was comparable between the two locations. Intense light conditions favor regeneration of Betula sp. (Betula platyphylla and B. ermanii). In contrast, for Abies sachalinensis and Picea glehnii, the light intensity had a negative effect, so it was concluded that regeneration of conifers would be limited under the condition where strong winds form large gaps.
8
Brlansky, R. H., D. S. Howd, P. Broadbent, and V. D. Damsteegt. "Histology of Sweet Orange Stem Pitting Caused by an Australian Isolate of Citrus tristeza virus." Plant Disease 86, no. 10 (October 2002): 1169–74. http://dx.doi.org/10.1094/pdis.2002.86.10.1169.
Full textAbstract:
Some strains of the Citrus tristeza virus (CTV) cause stem pitting in sweet orange (Citrus sinensis (L.) Osbeck). This abnormality causes tree decline and reduction in fruit size and yield of affected citrus trees. Stem-pitting symptoms can occur on trunks, on all sizes of limbs, and on the twigs where fruit are produced. Variously sized pits or grooves in the wood often contain a yellow gum. Irregular growth of the phloem occurs in the area of these xylem pits. The histology of stem pitting caused by an Australian CTV isolate was studied in sweet orange using light and electron microscopy. Using scanning electron microscopy, details of the wood pits containing the gumming material were revealed. In thin sections of bark tissue, outgrowths of the phloem tissue were found at various intervals that corresponded to the pits in the wood. Higher numbers of viral inclusions were detected in the phloem outgrowths than were present in the other sieve elements.
9
Tu, Min-cheng, Joshua Caplan, Sasha Eisenman, and Bridget Wadzuk. "When Green Infrastructure Turns Grey: Plant Water Stress as a Consequence of Overdesign in a Tree Trench System." Water 12, no. 2 (February 19, 2020): 573. http://dx.doi.org/10.3390/w12020573.
Full textAbstract:
Green infrastructure (GI) systems are often overdesigned. This may be a byproduct of static sizing (e.g., accounting for a design storm’s runoff volume but not exfiltration rates) or may be deliberate (e.g., buffering against performance loss through time). In tree trenches and other GI systems that require stormwater to accumulate in an infiltration bed before it contacts the planting medium, overdesign could reduce plant water availability significantly. This study investigated the hydrological dynamics and water relations of an overdesigned tree trench system and identified factors contributing to, compounding, and mitigating the risk of plant stress. Water in the infiltration bed reached soil pits only once in three years, with that event occurring during a hydrant release. Moreover, minimal water was retained in soil pits during the event due to the hydraulic properties of the soil media. Through a growing season, one of the two tree types frequently experienced water stress, while the other did so only rarely. These contrasting responses can likely be attributed to roots being largely confined to the soil pits vs. reaching a deeper water source, respectively. Results of this study demonstrate that, in systems where soil pits are embedded in infiltration beds, overdesign can raise the storm size required for water to reach the soil media, reducing plant water availability between storms, and ultimately inducing physiological stress.
10
Akkermans‐Rutgers, Marlot, Jeannette Doornenbal, Annelies Kassenberg, Roel Bosker, and Simone Doolaard. "Is the twig bent as the tree is inclined? Children and parents interacting with school‐distributed literacy assignments." Psychology in the Schools 58, no. 2 (November 20, 2020): 377–99. http://dx.doi.org/10.1002/pits.22452.
Full textDissertations / Theses on the topic "Tree pits"
1
Ng, Yuk-yin Judith, and 吳鈺賢. "Soil moisture and related edaphic properties of street-tree pits in urban Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B42575321.
Full text
2
Ng, Yuk-yin Judith. "Soil moisture and related edaphic properties of street-tree pits in urban Hong Kong." Click to view the E-thesis via HKUTO, 1999. http://sunzi.lib.hku.hk/hkuto/record/B42575321.
Full text
3
de, la Mota Daniel Francisco Javier. "Water Fluxes in Soil-Pavement Systems: Integrating Trees, Soils and Infrastructure." Diss., Virginia Tech, 2019. http://hdl.handle.net/10919/99419.
Full textAbstract:
In urban areas, trees are often planted in bare soil sidewalk openings (tree pits) which recently are being covered with permeable pavements. Pavements are known to alter soil moisture and temperature, and may have implications for tree growth, root development and depth, drought resilience, and sidewalk lifting. Furthermore, tree pits are often the only unsealed soil surface and are important for water exchange between soil and atmosphere. Therefore, covering tree pits with pavement, even permeable, may have implications for the urban water balance and stormwater management. A better understanding of permeable pavement on tree pavement soil system functioning can inform improved tree pit and street design for greater sustainability of urban environments.
We conducted experiments at two sites in Virginia, USA (Mountains and Coastal Plain) with different climate and soil. At each location, we constructed 24 tree pits in a completely randomized experiment with two factors: paved with resin-bound porous-permeable pavement versus unpaved, and planted with Platanus x acerifolia 'Bloodgood' versus unplanted (n = 6). We measured tree stem diameter, root growth and depth, and soil water content and temperature over two growing seasons. We also monitored tree sap flow one week in June 2017 at the Mountains. In addition, we calibrated and validated a soil water flow model, HYDRUS-1D, to predict soil water distribution for different rooting depths, soil textures and pavement thicknesses.
Trees in paved tree pits grew larger, with stem diameters 29% (Mountains) and 51% (Coastal Plain) greater. Roots developed faster under pavement, possibly due to the increased soil water content and the extended root growing season (14 more days). Tree transpiration was 33% of unpaved and planted pit water outputs, while it was 64% for paved and planted pits. In June 2016, planted pits had decreased root-zone water storage, while unplanted pits showed increased storage. A water balance of the entire experimental site showed overall decreased soil water storage due to tree water extraction becoming the dominant factor. HYDRUS-1D provided overall best results for model validation at 10 cm depth from soil surface (NSE = 0.447 for planted and paved tree pits), compared to 30- and 60 cm depths. HYDRUS-1D simulations with greater pavement thickness resulted in changes in predicted soil water content at the Coastal Plain, with higher values at 10- and 30-cm depths, but lower values at 60-cm depth. At the Mountains, virtually no difference was observed, possibly due to different soil texture (sandy vs clayey).
Tree pits with permeable pavement accelerated tree establishment, but promoted shallower roots, possibly increasing root-pavement conflicts and tree drought susceptibility. Paved tree pits resulted in larger trees, increasing tree transpiration, but reduced soil evaporation compared to unpaved pits. Larger bare soil pits surrounded by permeable pavement might yield the best results to improve urban stormwater retention. Also, HYDRUS 1D was successful at simulating soil water content at 10-cm depth and may be valuable to inform streetscape design and planning.PHD
4
Shi, Chunming. "Paleoclimate information archived in tree-ring width and tree-ring stable isotopes on Tibetan Plateau." Versailles-St Quentin en Yvelines, 2011. http://www.theses.fr/2011VERS0023.
Full textAbstract:
Le plateau tibétain, avec une altitude moyenne de 4000m, est appelé le « troisième pôle de la Terre ». Il est l’objet d’une attention particulière dans les études qui portent sur le changement climatique global. D’une part, il constitue un obstacle physique à la circulation atmosphérique et, d’autre part, il agit comme un régulateur thermique qui réchauffe l’air sus-jacent en été et le refroidit en hiver. Le climat du plateau tibétain n’est pas une composante isolée du climat global mais bien une composante interactive avec les autres systèmes. En particulier, le plateau joue un rôle décisif dans la variabilité de la mousson asiatique qui affecte une aire géographique conséquente et densément peuplée. Soixante pourcent des eaux du Fleuve Jaune, dont dépendent plus de 100 millions de personnes et une industrie en pleine expansion, proviennent du plateau (Zhao et al. , 2008). Or, le débit de ce fleuve a diminué régulièrement depuis les années 1950 (Liu and Xia, 2004; Chang et al. , 2007). Il est crucial de comprendre comment les variations climatiques locales et globales affectent l’approvisionnement en eau de cette région appelée le « Château d’eau » de la Chine. Les enregistrements instrumentaux, qui ont généralement démarré dans la seconde moitié du 20ème siècle, sont toutefois trop courts pour appréhender la variabilité climatique. Le plateau tibétain offre une variété d’archives climatiques permettant d’étendre notre connaissance de la variabilité du climat au-delà des séries instrumentales. Le climat de haute altitude permet la formation de cernes d’arbres qui peuvent être parfaitement datés et offrent l’accès à une résolution saisonnière à annuelle. La largeur des cernes et la composition isotopique d’arbres anciens permettent, dans certaines conditions, de quantifier des paramètres clés du climat. Le potentiel de ces proxies pour reconstruire la variabilité des paramètres liés au cycle hydrologique (précipitation, humidité relative, couverture nuageuse, débit des rivières) reste à explorer. Cette thèse vise à répondre aux questions concernant la variabilité climatique sur le plateau au cours des derniers siècles. Les objectifs spécifiques sont : a) de déterminer les relations entre les variables climatiques du plateau et les paramètres des arbres (largeurs de cernes et composition isotopique de l’oxygène et du carbone de la cellulose) sur la période instrumentale, b) d’obtenir de longues séries de valeurs de largeurs de cernes et de composition isotopique de la cellulose et de les interpréter en termes climatiques, c) de reconstruire la variabilité climatique à partir de ces données et de leur confrontation à d’autres enregistrements de la variabilité climatique passéeThe Tibetan plateau, 4000m high, is called the earth’s third pole. No other area in the world is a water repository of such size, serving as a lifeline for much of a continent and millions of people in countries downstream. The water supply in this head water region accounts for instance for more than 60% of the total runoff to the Yellow River (Zhao et al. , 2008). Climate evolution in Tibet would potentially have serious impacts. The current climate change could thus cause a rapid retreat of the glaciers with significant consequences on water resources in the region. However, the glacier water balance is influenced not only by local temperature variations, but also by precipitation ones. In southern Tibet, precipitation events exhibit a strong interannual-to-decadal variability directly related to the variability of Indian monsoon rainfall. To decipher the causes and the driving forces of water supply variability in the ‘water tower’ of China, it is therefore crucial to understand how it is affected by local and global climate changes. The climate and river flow in the source region of the Yellow River are documented through instrumental records starting in the 20th century. The Tibetan Plateau can offer a variety of climate archives but high-resolution proxy data, which are needed to document long-term climate change impacts, are still scarce in this area. The width and the isotopic composition of tree-ring have shown to be very valuable proxies of climate parameters. However, the potential of these proxies for reconstructing parameters linked to the hydrological cycle (precipitation, relative humidity, cloud cover, river flow) in this area still needs to be investigated. This thesis aims at characterizing climate variability in the Southern Tibetan Plateau over the last centuries. The main goals are: a) to determine the relations between some key climate parameters and tree-ring parameters (ring-width and cellulose 13C and 18O) over the instrumental time-period, b) to reconstruct and interpret climate variability in the South-Eastern Plateau over the last centuries from new tree-ring chronologies
5
Santini, Filippo. "Towards the characterisation of adaptive syndromes of Mediterranean pines: insights through innovative tree phenotyping techniques." Doctoral thesis, Universitat de Lleida, 2020. http://hdl.handle.net/10803/668898.
Full textAbstract:
En aquesta tesi, es van estudiar patrons de variació genètica intraespecífica en caracters funcionals
de Pinus halepensis Mill., Pinus nigra Arnold i Pinus sylvestris L. Un conjunt de tècniques de fenotipat
ben establertes van ser combinades amb dades de teledetecció obtingudes amb un dron (unmanned
aerial vehicle, UAV). Les imatges d’UAV van indicar una diferenciació genètica en estratègies
adaptatives de P. halepensis, determinada per la variació en la disponibilitat d'aigua dins la distribució
geogràfica de l’espècie. En P. nigra, la diferenciació genètica va ser determinada per les temperatures
mínimes anuals. D'altra banda, la disponibilitat d'aigua va tenir una importància marginal com a
determinant de la variació intraespecífica en aquesta espècie. Així mateix es va detectar una escassa
diferenciació genètica en P. sylvestris en trets relacionats amb l'ús d'aigua. No obstant això, aquesta
espècie va presentar una considerable variació plàstica en l'eficiència de l'ús de l'aigua. La informació
proporcionada per aquesta tesi és crucial per comprendre la dinàmica futura d'aquestes espècies i
emfatitza la vulnerabilitat de P. nigra i P. sylvestris en el context del canvi climàtic A més, els resultats
d'aquesta tesi subratllen l'ús d'imatges derivades d'UAVs com potencials eines de fenotipat massiu en
espècies forestals.En esta tesis, se estudió la variación genética intraespecífica de rasgos funcionales de Pinus halepensis Mill., Pinus nigra Arnold y Pinus sylvestris L., combinando técnicas de fenotipado bien establecidas con datos de teledetección obtenidos un dron (unmanned aerial vehicle, UAV). Las imágenes de UAV revelaron una diferenciación genética en estrategias adaptativas de P. halepensis, determinada por la existencia de poblaciones adaptadas a la sequía. En P. nigra, la diferenciación genética fue determinada por las temperaturas mínimas anuales. Por otro lado, la disponibilidad de agua tuvo una importancia marginal como determinante de la variación intraespecifica en esta especie. Asimismo se detectó una escasa diferenciación genética en P. sylvestris en rasgos relacionados con el uso de agua. Sin embargo, esta especie presentó una considerable variación plástica en la eficiencia del uso del agua. La información proporcionada por esta tesis es crucial para comprender la dinámica futura de estas especies y enfatiza la vulnerabilidad de P. nigra y P. sylvestris en el contexto del cambio climático Además, los resultados de esta tesis subrayan el uso de imágenes derivadas de UAVs como potenciales herramientas de fenotipado masivo en especies forestales.
This thesis studied the intra-specific genetic variation in functional traits of Pinus halepensis Mill., Pinus nigra Arnold and Pinus sylvestris L. by combining well-established phenotyping techniques with remote sensing data obtained with an Unmanned Aerial Vehicle (UAV). UAV-imagery revealed a genetic divergence in adaptive strategies in P. halepensis, related to the presence of drought-adapted populations. In P. nigra, genetic variation was related to winter temperatures, while water availability had a weak role as driver of intra-specific divergence. Similarly, a weak genetic differentiation emerged in P. sylvestris in water-related traits, although this species showed high plastic variation in water use efficiency. The information provided by this thesis is crucial to understand the future dynamics of these pines, highlighting the vulnerability of P. nigra and P. sylvestris in the context of climate change. In addition, this thesis provided a strong support for the use of UAV-derived imagery as phenotyping tool in forest species.
6
Li, Shan [Verfasser]. "Predicting angiosperm tree mortality based on embolism resistance, cambium vitality and intervessel pit membrane thickness / Shan Li." Ulm : Universität Ulm, 2017. http://d-nb.info/1126579602/34.
Full text
7
Torres, Lezcano Estanis. "Desarrollo de métodos de predicción de la incidencia de 'bitter pit' en plantaciones de manzanas ‘Golden Smoothee’ (Malus domestica, L. Borkh.)." Doctoral thesis, Universitat de Lleida, 2018. http://hdl.handle.net/10803/665244.
Full textAbstract:
El bitter pit és la fisiopatia més important en molts cultivars de pomes. No obstant, no existeix una estratègia completament efectiva per al seu control, per aquest motiu, un mètode de predicció que identifiqui anys i plantacions amb un alt potencial de desenvolupar la fisiopatia permetrà evitar pèrdues econòmiques, especialment durant la conservació i confecció.
L’objectiu principal de la present tesi doctoral va ser la posada a punt d’un sistema de predicció de la incidència del bitter pit en plantacions de poma ‘Golden Smoothee’. Per això, es van investigar diferents mètodes basats en tres tecnologies diferents: i) l’anàlisi mineralògic de fruits en diferent època (en estadis primerencs i a recol·lecció), ii) la inducció de símptomes (infiltració de Mg, banys amb etefón, embossat de fruits i mètode passiu) i iii ) l’espectroscopía VIS/NIR. Els diferents mètodes es van avaluar en diferents períodes de creixement del fruit. Paral·lelament, es va avaluar i quantificar l’eficàcia de diferents estratègies per mitigar l’aparició de bitter pit basades en aplicacions de CaCl2 a pre i postcollita (aplicacions radiculares, foliars i banys en poscosecha).
L’anàlisi primerenc de Ca en fruit a 60 dies després de la floració (DDPF) va mostrar una precisió en la predicció similar o millor que l’anàlisi a recol·lecció. Es va definir un valor de referència de 60 DDPF de 11 mg de Ca 100 g-1 de pes fresc, per sobre del qual es minimitza la incidència de bitter pit. La majoria de mètodes basats en induir símptomes, a excepció de l’embossat, van mostrar eficàcia a partir dels 40 dies abans de la recol·lecció (DAR), amb una correlació amb el bitter pit de postcollita del 70-80%. La espectroscopía VIS/NIR va mostrar resultats poc satisfactoris per a la predicció del bitter pit, però va ser capaç de discriminar fruits afectats quan els símptomes eren visibles a postcollita. Finalment, es va disenyar un model de predicció per al bitter pit basat en l’anàlisi de Ca en fruit a 60 DDPF i el mètode passiu a partir de 40 DAR. Respecte la mitigació del bitter pit, els resultats obtinguts en els anys amb alta incidència van mostrar una reducció del 20% a un 12%, 8% o 3% mitjançant aplicacions foliars, banys de postcollita o la combinació d’ambdues, respectivament, per tant, les aplicacions foliars de CaCl2 així com els banys postcollita serien pràctiques a recomanar en els casos d’alt risc de bitter pit.El bitter pit es la fisiopaía más importante en muchos cultivares de manzana. Sin embargo, no existe una estrategia de control completamente efectiva, por lo que un método de predicción que identifique años y plantaciones con alto potencial de desarrollar la fisiopatía permitirá evitar pérdidas económicas, especialmente durante la conservación y confección. El objetivo principal de la presente tesis doctoral fue la puesta a punto de un sistema de predicción de la incidencia de bitter pit en plantaciones de manzanas ‘Golden Smoothee’. Para ello, se investigaron diferentes métodos de predicción basados en tres tecnologías distintas: i) el análisis mineralógico de fruto (en estadios tempranos y en recolección), ii) la inducción de síntomas (infiltración de Mg, baños con etefón, embolsado de frutos y método pasivo) y iii) la espectroscopía VIS/NIR. Los distintos métodos se evaluaron en diferentes períodos de crecimiento del fruto. Paralelamente, se evaluó y cuantificó la eficacia de distintas estrategias para la mitigación del bitter pit basadas en aportaciones de CaCl2 en pre y poscosecha (aplicaciones radiculares, foliares y baños en poscosecha). El análisis temprano de Ca en fruto a 60 días después de plena floración (DDPF) mostró una precisión de predicción similar o mejor que el análisis de Ca en recolección. Se definió un umbral de referencia a 60 DDPF de 11 mg Ca 100 g-1 de peso fresco, por encima del cual se minimizó el riesgo de aparición del bitter pit. La mayoría de métodos basados en inducir síntomas, a excepción del embolsado de frutos, mostraron eficacia a partir de los 40 días antes de recolección (DAR), con una correlación con el bitter pit de poscosecha del 70-80%. La espectroscopía VIS/NIR mostró resultados poco satisfactorios para la predicción del bitter pit, sin embargo, sí fue capaz de discriminar frutos afectados cuando los síntomas eran visibles en poscosecha. Finalmente, se diseñó un modelo de predicción del bitter pit basado en el análisis de Ca en fruto a 60 DDPF y el método pasivo a partir de 40 DAR. Respecto la mitigación del bitter pit, los resultados obtenidos en años con alta incidencia mostraron una reducción de un 20% a un 12%, 8% o 3% mediante aplicaciones foliares, baños en poscosecha o la combinación de ambas, respectivamente, por lo que tanto las aplicaciones foliares de CaCl2 como los baños poscosecha serían prácticas a recomendar en el caso de riesgo de bitter pit.
Bitter pit is the most important physiological disorder in many apple cultivars. However, there is no a completely effective control strategy, therefore, a prediction method that identifies years and orchards with high potential to develop bitter pit will allow reducing economic losses, especially during storage and fruit packing. The main objective of this PhD thesis was the development of a system to predict the incidence of bitter pit for ‘Golden Smoothee’ apple orchards. For this, different methods to predict bitter pit based on three different technologies were investigated: i) mineral analysis (at early stages and at harvest period, ii) induction of symptoms (Mg infiltration, dips with etephon solution, bagging of fruit and passive method) and iii) VIS/NIR spectrophotometry. The different methods were tested in different fruit growth stages. At the same time, the efficacy of different strategies based on CaCl2 applications at pre- and postharvest (fertigation, foliar and postharvest dips) to mitigate bitter pit incidence, were evaluated and quantified. The accuracy of mineral analysis at early development fruit after 60 days after full bloom (DAFB) was better or equal than Ca analysis at harvest. A reference threshold at 60 DAFB of 11 mg Ca 100 g-1 fresh weight was defined. Values equal or higher indicated a low risk of bitter pit. Most methods based on inducing symptoms, with the exception of bagging fruit, showed efficacy from 40 days before harvest (DBH), with a correlation with bitter pit at postharvest of 70-80%. VIS/NIR spectrophotometry showed unsatisfactory results for bitter pit prediction, however, it was able to discriminate affected apples when the symptoms were visible at postharvest. Finally, a bitter pit prediction model based on the analysis of Ca in fruitlet at 60 DAFB and the passive method from 40 DBH was designed. Regarding bitter pit mitigation, the results obtained in seasons with a high incidence showed a reduction from 20% to 12%, 8% or 3% using Ca sprays, postharvest dips or the combination of both, respectively. Therefore, Ca sprays and postharvest dips in CaCl2 solutions are recommended practices when there is a diagnostic of high risk of bitter pit.
8
Lenart, Melanie. "A comparative study of soil disturbance from uprooted trees, and mound and pit decay in Puerto Rico and Colorado." Diss., The University of Arizona, 2003. http://hdl.handle.net/10150/289948.
Full textAbstract:
The toppling of trees forms mounds of disturbed sediment and pits from which the mound removes sediment, rocks, and organic matter. Sites of uprooted trees in Puerto Rico and Colorado were examined (1) to compare areas and volumes of mounds and pits relative to tree size, (2) to compare areas and volumes of mounds and pits formed during catastrophic events at the landscape scale, and (3) to consider decay of mounds and pits after formation. For a given basal area, the analyses found no difference among sites in area and volume of freshly formed individual mounds and pits. For landscape-level catastrophic uprooting, the percent of toppled trees in a plot can explain 85% and 87% of the areas and volumes, respectively, of the quantity of soil uplifted. Exponential decay coefficients developed by monitoring mound/pit complexes indicate that mounds and pits at the humid tropical site in Puerto Rico decay in about 74% and 57% of the time, respectively, of mounds and pits at a temperate Colorado site. Decay coefficients developed for the Colorado site indicate that mounds and pits are reduced to 10% of their original volume within 30 and 78 years, respectively. Coefficients for Puerto Rico suggest that a similar reduction in volume requires 17 years, whereas pits generally fill within a decade.
9
Jones, Elies. "Eco-innovation : tools to facilitate early-stage workshops." Thesis, Brunel University, 2003. http://bura.brunel.ac.uk/handle/2438/5377.
Full textAbstract:
This thesis presents research carried out into the use of creative tools at the early stages of eco-innovation. Eco-innovation is a practical approach aiming to develop new products and processes which significantly decrease our impact on the environment. Designers are trained to develop profitable products that increase production and consumption. Eco-innovation is a new discipline in which designers can radically reduce the environmental burdens of production and consumption through the innovation of new types of products and services. The main aim of this research was to develop an approach that would promote significant environmental improvements whilst remaining a practical, design-focused discipline. Problems and under-investigated aspects of eco-innovation were identified: • Creative approaches at early stages of eco-innovation were under-investigated and few tools had been developed for use at the early stages. • Empirical design research techniques had rarely been used to assess new eco-innovation tools or to inform their subsequent development. The focus of the research work was the development and testing of tools to facilitate workshops at the early stages of eco-innovation. Not only was the goal to facilitate the generation of radical ideas but also to ensure that these were developed into appropriate solutions having the potential to be taken up in industry. The development of the tools was based on literature research, worked examples and interviews. The tools were tested in controlled workshop experiments and the results were analysed using various empirical techniques. First, an idea-recording technique to improve the efficiency of generating and harvesting ideas in a team design process was developed. This novel tool was called the Product Ideas Tree (PIT) diagram. The tool was tested for its ability to facilitate design workshops. Secondly, a structured approach to innovation - the theory of inventive problem solving (TRIZ) - was investigated. Worked examples using some of the tools from TRIZ were presented and a limited number of tools were selected and simplified for testing in team design workshops. The PIT diagram and TRIZ tools experiments established which attributes of the tools and approaches were most beneficial. The development and testing of these specific tools provided the following general contributions to eco-innovation: • A model for eco-innovation that describes the factors influencing the discipline and the attributes of good practice. • A recommended process to transform radical ideas into appropriate solutions to improve their potential to be taken up in industry. • General insights into the use of tools in early-stage workshops such as: tool selection, integration into existing processes, system-level problem solving and providing thematic information. • Suggested improvements for testing tools in controlled workshop experiments.
10
Fridjonsson, Liselotte, Mathilda Brink, and Malin Brytting. "Hållbar Textil Produktutveckling : med växtfärgning." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-518.
Full textAbstract:
Författarna har haft ett samarbete med Panduro Hobby i samband med deras årliga miljökampanj. Syftet med examensarbetet har varit att med hjälp av befintliga produktutvecklingsprocesser och livscykelanalyser (LCA) ta fram en hållbar textil produkt med växtfärgning. Tanken var att konsumenter sedan själva skall kunna ta fram och växtfärga denna hållbara textilprodukt. Miljömedvetenhet och hållbarhet inom textilindustrin är ett aktuellt ämne. Trots det saknar dagens konsumenter förståelse för textilindustrins påverkan på miljön och har bristande kunskap om textila material för att kunna göra miljövänliga val ute i handeln. Både konsumenter och företag uttrycker att de gärna vill bidra till en mer miljövänlig textilindustri men att de saknar kännedom, resurser och verktyg för att göra det. Därför valde författarna av examensarbetet att undersöka hur en hållbar textil produkt kan tas fram med hjälp av livscykelanalyser, produktutvecklingsmetoden Product Ideas Tree (PIT) samt växtfärgning. Alla steg under produktutvecklingsprocessen valdes ur miljöhänsyn och efter de förutsättningar som krävs för att göra en så miljövänlig textil produkt som möjligt. Resultatet av undersökningen blev en växtfärgad tygkasse i 100 % lin. Efter framtagningen av produkten gjordes en livscykelanalys benämnd MET-matris för att analysera produktens miljöpåfrestning. Matrisen konstaterade att produkten inte har avsevärda miljöbrister. Med examensarbetet och den framtagna produkten vill författarna uppmuntra konsumenter och företag till att fortsätta visa engagemang och intresse för förändringar som gynnar miljön med förhoppningen om att få fler att agera mer hållbart.The authors have had a collaboration with Panduro Hobby in addition to their annual environmental sustainability campaign. The aim of the thesis has been to develop a sustainable textile product with natural dye using existing product development processes and Life Cycle Assessment (LCA). The idea was that consumers later on would be able to produce this sustainable textile product and dye it themselves. Environmental awareness and sustainability in the textile industry is a topical subject. Nevertheless many consumers lack sufficient knowledge of textile materials to make environmentally friendly choices in the commerce. Both consumers and businesses express that they would like to contribute to a more environmentally friendly textile industry, but that they lack the knowledge, resources and tools to do it. Therefore, the authors of the thesis chose to explore how a sustainable textile product may be produced with the help of Life Cycle Assessment and the product development method Product Ideas Tree (PIT). All steps in the product development process were carefully chosen with consideration to the environment and the circumstances required to make the textile product as sustainable as possible. The study resulted in the development of a canvas bag made out of 100% linen dyed it with natural dye. After the product development a Life Cycle Analysis, referred to as MET Matrix, was done to analyse the product's environmental strain. The matrix noted that the product does not have significant environmental burdens. With the thesis and the produced product the authors would like to encourage consumers and businesses to continue to show commitment and interest in changes that benefit the environment, with the hope of getting more people to act more sustainably.
Books on the topic "Tree pits"
2
1947-, Johnson Linda, and Van Horn George ill, eds. Tree vipers. Vero Beach, Fla: Rourke, 1987.
Find full text
6
ill, Budwine Greg, ed. Three little pigs =: Los tres cerditos. Houston: Advance, 2008.
Find full text
7
ill, Joan Pere, ed. The three little pigs =: Los tres cerditos. San Francisco: Chronicle Books, 2006.
Find full text
8
ill, Cuéllar Olga 1953, ed. The three little pigs =: Los tres cerditos. Canandaigua, NY: Adirondack Books, 2014.
Find full textBook chapters on the topic "Tree pits"
1
Bearce, Stephanie. "On Pins and Needles." In Twisted True Tales from Science Medical Mayhem, 26–30. New York: Routledge, 2021. http://dx.doi.org/10.4324/9781003239291-7.
Full text
2
Decelle, Rémi, Phuc Ngo, Isabelle Debled-Rennesson, Frédéric Mothe, and Fleur Longuetaud. "Pith Estimation on Tree Log End Images." In Reproducible Research in Pattern Recognition, 101–20. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-76423-4_7.
Full text
3
Kużelewski, Andrzej, Eugeniusz Zieniuk, Agnieszka Bołtuć, and Krzystof Szerszeń. "Modified Binary Tree in the Fast PIES for 2D Problems with Complex Shapes." In Lecture Notes in Computer Science, 1–14. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-50417-5_1.
Full text
4
Crivellaro, Alan, and Fritz Hans Schweingruber. "Introduction." In Atlas of Wood, Bark and Pith Anatomy of Eastern Mediterranean Trees and Shrubs, 1–2. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-37235-3_1.
Full text
5
Crivellaro, Alan, and Fritz Hans Schweingruber. "Materials and Methods." In Atlas of Wood, Bark and Pith Anatomy of Eastern Mediterranean Trees and Shrubs, 3. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-37235-3_2.
Full text
6
Crivellaro, Alan, and Fritz Hans Schweingruber. "Definition of anatomical features." In Atlas of Wood, Bark and Pith Anatomy of Eastern Mediterranean Trees and Shrubs, 5–36. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-37235-3_3.
Full text
7
Crivellaro, Alan, and Fritz Hans Schweingruber. "Identification keys." In Atlas of Wood, Bark and Pith Anatomy of Eastern Mediterranean Trees and Shrubs, 37–47. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-37235-3_4.
Full text
8
Crivellaro, Alan, and Fritz Hans Schweingruber. "Anatomical description of species." In Atlas of Wood, Bark and Pith Anatomy of Eastern Mediterranean Trees and Shrubs, 49–573. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-37235-3_5.
Full text
9
Fledelius, Hans C. "Optical pits and (other) acoustic fistulas. True B-scan findings or artifacts? An ultrasonic report on six patients." In Documenta Ophthalmologica Proceedings Series, 559–64. Dordrecht: Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-011-5802-2_71.
Full text
10
Rubenstein, Roberta. "Home/lands and Contested Motherhood: The Bean Trees and Pigs in Heaven, Barbara Kingsolver." In Home Matters, 53–64. New York: Palgrave Macmillan US, 2001. http://dx.doi.org/10.1057/9780312299750_4.
Full textConference papers on the topic "Tree pits"
1
"Adsorption of Methylene Blue onto Chemically Prepared Activated Carbon from Date Palm Pits: Kinetics and Thermodynamics." In By-Products of Palm Trees and Their Applications. Materials Research Forum LLC, 2019. http://dx.doi.org/10.21741/9781644900178-23.
Full text
2
Stärk, K. D. C., and B. Rasmussen. "Hazard analysis of Salmonella in pork using tree diagrams." In 10th International Conference on the Epidemiology and Control of Biological, Chemical and Physical Hazards in Pigs and Pork. Iowa State University, Digital Press, 1999. http://dx.doi.org/10.31274/safepork-180809-994.
Full text
3
Vilar, M. J., J. Ranta, S. Virtanen, R. Laukkanen-Ninios, and H. Korkeala. "The True Seroprevalence of Enteropathogenic Yersinia in Pigs, a Hayesian Approach." In Eighth International Symposium on the Epidemiology and Control of Foodborne Pathogens in Pork. Iowa State University, Digital Press, 2013. http://dx.doi.org/10.31274/safepork-180809-899.
Full text
4
Brückner-Foit, A., and C. Ziegler. "Time-Dependent Reliability of Ceramic Components Subjected to High-Temperature Loading in a Corrosive Environment." In ASME 1999 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/99-gt-233.
Full textAbstract:
The time-dependent reliability of ceramic components subjected to high temperature loading can be analysed using multiaxial Weibull theory and its generalisations. In this approach it is assumed that no additional flaws are initiated during exposure to high temperatures. However, this may not be true in a highly corrosive environment such as in a combustion chamber. Additional flaws can be generated by surface oxidation, volume damage or by formation of circular pits on the surface of the component. These cases are considered in this paper. The relations for the failure probabilities are derived starting from classical Weibull theory. A fastener bolt for the ceramic lining of a combustion chamber is considered as an example.
5
Bubel, Julian, Marc-André Pick, and Jürgen Grabe. "Stability of Artificial Subaqueous Slopes in Sandy Soils Under Wave Loads." In ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/omae2015-41827.
Full textAbstract:
Shallow foundation structures in marine environments can rarely be placed on top of the sea floor. Weak soils usually need to be excavated to place the structure on more stable ground. Steep but stable slopes of the resulting pit meet both economic and ecologic aims as they minimise material movement and sediment disturbance. This paper focuses changes of geometry of submarine slopes in non-cohesive soils (erosion, sedimentation, breach failure, liquefaction failure) due to surface waves. After Terzaghi the angle between slope and the horizontal of the ground surface of cohesionless soil is at most equal to the critical state friction angle, as obviously true for dry soil. However, it can be observed that natural submarine slopes of sandy soils are always mildly sloped. During the construction of artificial submarine pits under offshore conditions it should be considered that the long-term slope-inclination is less than onshore due to hydrodynamic actions (e. g. flow, waves, earthquakes). Large surface waves cause excess pore water pressures within the soil body, leading to a reduction of effective stresses and in case of submarine slopes to changes of the slope geometry depending on wave length L, wave height H, water depth h and soil properties (permeability k, relative density Dr). During our preliminary work we investigated such processes based on the coupling of linear wave theory and linear quasistatic consolidation theory (e.g. [1]). With the help of numerical modelling we solved corresponding equations considering also materially nonlinear consolidation. However, deformations were always limited by used Lagrangian-FEM. Recent developments at our Institute enable the use of an Eulerian-FEM approach with an u-p-Formulation for fully saturated soil [2]. This allows larger deformations of the subaqueous slope to be numerically investigated.
6
Alfonso, L., F. Caleyo, J. M. Hallen, and J. Araujo. "On the Applicability of Extreme Value Statistics in the Prediction of Maximum Pit Depth in Heavily Corroded Non-Piggable Buried Pipelines." In 2010 8th International Pipeline Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ipc2010-31321.
Full textAbstract:
There exists a large number of works aimed at the application of Extreme Value Statistics to corrosion. However, there is a lack of studies devoted to the applicability of the Gumbel method to the prediction of maximum pitting-corrosion depth. This is especially true for works considering the typical pit densities and spatial patterns in long, underground pipelines. In the presence of spatial pit clustering, estimations could deteriorate, raising the need to increase the total inspection area in order to obtain the desired accuracy for the estimated maximum pit depth. In most practical situations, pit-depth samples collected along a pipeline belong to distinguishable groups, due to differences in corrosion environments. For example, it is quite probable that samples collected from the pipeline’s upper and lower external surfaces will differ and represent different pit populations. In that case, maximum pit-depth estimations should be made separately for these two quite different populations. Therefore, a good strategy to improve maximum pit-depth estimations is critically dependent upon a careful selection of the inspection area used for the extreme value analysis. The goal should be to obtain sampling sections that contain a pit population as homogenous as possible with regard to corrosion conditions. In this study, the aforementioned strategy is carefully tested by comparing extreme-value-oriented Monte Carlo simulations of maximum pit depth with the results of inline inspections. It was found that the variance to mean ratio, a measure of randomness, and the mean squared error of the maximum pit-depth estimations were considerably reduced, compared with the errors obtained for the entire pipeline area, when the inspection areas were selected based on corrosion-condition homogeneity.
7
Zhu, Lin, Jiaxing Lu, and Yihong Chen. "HDI-Forest: Highest Density Interval Regression Forest." In Twenty-Eighth International Joint Conference on Artificial Intelligence {IJCAI-19}. California: International Joint Conferences on Artificial Intelligence Organization, 2019. http://dx.doi.org/10.24963/ijcai.2019/621.
Full textAbstract:
By seeking the narrowest prediction intervals (PIs) that satisfy the specified coverage probability requirements, the recently proposed quality-based PI learning principle can extract high-quality PIs that better summarize the predictive certainty in regression tasks, and has been widely applied to solve many practical problems. Currently, the state-of-the-art quality-based PI estimation methods are based on deep neural networks or linear models. In this paper, we propose Highest Density Interval Regression Forest (HDI-Forest), a novel quality-based PI estimation method that is instead based on Random Forest. HDI-Forest does not require additional model training, and directly reuses the trees learned in a standard Random Forest model. By utilizing the special properties of Random Forest, HDI-Forest could efficiently and more directly optimize the PI quality metrics. Extensive experiments on benchmark datasets show that HDI-Forest significantly outperforms previous approaches, reducing the average PI width by over 20% while achieving the same or better coverage probability.
8
Lee, Gary Y. H., Ohgeon Kwon, Zuwairi Ramli, and Zaki Mohamad Afifi. "Crude Furnace Creep Assessment and High Temperature Degradation." In ASME 2017 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/pvp2017-65046.
Full textAbstract:
Creep calculations indicate a crude furnace radiant section carbon steel tubes exceeding their life fraction due to flame impingement reaching up to 700°C for a year. The ambiguity of the temperature and material data means the life fraction of creep calculations were based on limited inspection data and infra-red scanning giving a conservative indication of end of life. Due to unavailable tubes in stock, a planned pit stop cannot be arranged due to economic and safety reasons as the furnace may not be started back up safely. To safeguard the integrity of the furnace until the planned outage, the temperature on the furnace tube was stabilized to a current limit of 540°C through improvements in burner operations. The crude diet was also maintained within the crude acceptance envelope. Visual checks at every shift were done to ensure no observation from tube bulging or uneven flame pattern. A decision tree was created to facilitate quick decision making using a go/no go criteria of which tubes to replace during the August 2015 planned turnaround. The criteria set for the decision tree required tube wall thickness, surface hardness test, tube outer diameter ring gauge to be examined. Failing any of the criteria will require the tube to be replaced. The replaced tubes (one worst and one representative) will also be lab tested through destructive examination to identify the degradation mechanism and high temperature properties of the worst tubes to quantitatively define the high temperature properties and life fraction of the tubes that are left in the furnace. The lab test will provide results after a year of creep testing and can give assurance of continued furnace operation for 4 more years until the next outage. The final decision after the examination based on the decision tree was made required 17 tubes to be replaced in this turnaround. The worst degraded tubes were found to be at the vicinity of the initial observed location around the flame impingement zone.
9
Dann, Markus R., and Luc Huyse. "Pragmatic Approach to Estimate Corrosion Rates for Pipelines Subject to Complex Corrosion." In 2014 10th International Pipeline Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/ipc2014-33146.
Full textAbstract:
Corrosion is a common degradation process for most oil and gas pipelines in operation that can lead to leak and rupture failures. To avoid failures due to corrosion, integrity management plans for pipelines require fitness-for-service (FFS) assessments and remaining life analysis of the corrosion features that are detected by in-line inspections (ILIs). The objective of the present paper is to support the deterministic integrity and remaining life assessment of pipelines by introducing a pragmatic approach for the determination of corrosion rates from two inspections. The proposed approach is primarily tailored towards upstream and subsea pipelines that are subject to very high density internal corrosion rather than transmission pipelines with low to moderate densities of external features. ILI data may be subject to significant measurement errors and feature matching for two ILIs can become highly unreliable if high-density corrosion is present. To address these uncertainties, the backbone of the proposed approach is to focus on corrosion clusters rather than individual corrosion pits and a filtering process is utilized to identify true corrosion growth. The introduced approach is supported by theoretical knowledge and practical experience. The approach can be easily executed in spreadsheet software tools without the application of advanced statistical and probabilistic methods for the deterministic remaining life assessment in practice.
10
Purvis, Brian. "Pipeline Integrity Monitoring: What’s the Present Situation for Offshore Pipelines and the Future?" In 2010 8th International Pipeline Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ipc2010-31449.
Full textAbstract:
This paper will discuss both the present situation and future developments in Pipeline Integrity Monitoring. It will also highlight how integrity monitoring is a vital part of any Pipeline Integrity Management System (PIMS). To give the true picture of a pipeline’s condition, the integrity monitoring systems must identify those elements of the pipeline which are at most risk to any potential modes of failure. Pipeline integrity monitoring offshore tends to be the periodic monitoring of specified components above and below the water surface. This being in the form of long and short term monitoring programs, which are derived from threat identification, risk assessment and mitigation processes. These programs normally follow the relevant industry standards that define specific monitoring activities and frequencies, especially for the safety critical components. PIMS documentation review cycles can be long and complex, but should be undertaken on a regular basis. When these reviews are undertaken they don’t always use new data sources that could give us more information about potential failure modes. At present these processes tend to be more reactive or lagging in nature. The future monitoring of pipeline integrity should be more forward-looking and be proactive as well as being reactive. Where are the next major developments? We need to make better use of the data we have by studying trends, changes and impacts wherever possible. Also, have a better understanding of the in-service behaviour and how this can change over the life cycle of a pipeline system.
Reports on the topic "Tree pits"
1
Marx, D. H. Research on: A. Reclamation of borrow pits and denuded lands; B. Biochemical aspects of mycorrhizae of forest trees. Office of Scientific and Technical Information (OSTI), December 1990. http://dx.doi.org/10.2172/6174293.
Full text