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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

ProduÃÃo de biomassa de Bacillus sp. RAB9 por fermentaÃÃo submersa. / BIOMASS PRODUCTION OF Bacillus sp. RAB9 BY SUBMERGED FERMENTATION

CÃvita Teixeira de Sousa 04 March 2013 (has links)
As bactÃrias promotoras de crescimento em plantas (BPCP) representam uma parcela funcional ativa da biota do solo sÃo presentes na rizosfera no rizoplano e no interior de plantas hospedeiras O uso biotecnolÃgico dessas bactÃrias tem se intensificado nos Ãltimos anos O gÃnero Bacillus vem sendo continuamente citado em estudos relacionados a promoÃÃo de crescimento em espÃcies vegetais Algumas espÃcies podem ser aplicadas no tratamento de sementes, ÃrgÃos de propagaÃÃo vegetativa e mudas Diante disso o presente trabalho teve como objetivo avaliar a produÃÃo de biomassa de Bacillus sp (RAB9) com potencial uso na promoÃÃo de crescimento de mudas de bananeira A cepa Bacillus sp (RAB9) pertencente ao grupo das bactÃrias epifÃticas, foi isolada de rabanete proveniente da ColeÃÃo de Culturas do LaboratÃrio de Fitobacteriologia da Universidade Federal Rural de Pernambuco Os experimentos foram realizados em agitador orbital e em reator de bancada Em agitador orbital foi estudada a curva de crescimento da linhagem a 30ÂC para observar sua fase exponencial Para a produÃÃo de biomassa foram observados os efeitos da adiÃÃo do teor de peptona (5 a 50 g.L-1) no meio NYD (extrato de carne, extrato de levedura peptona de carne e dextrose) adiÃÃo de elementos secundÃrios (K2HPO4 e MgSO4) e fonte de nitrogÃnio inorgÃnico ((NH4)2SO4) Em reator de bancada foram realizados testes com diferentes vazÃes de ar em batelada simples bem como uma comparaÃÃo com batelada alimentada com o meio modificado As fermentaÃÃes nos reatores apresentaram formaÃÃo de espuma testes foram feitos com Ãleos vegetais (milho canola girassol soja) e mineral para verificaÃÃo do melhor antiespumante Posteriormente aos testes foram quantificadas a biomassa o aÃÃcar residual nitrogÃnio residual e nitrogÃnio amoniacal Com os resultados obtidos foi observado a importÃncia da adiÃÃo dos elementos (MgSO4 e (NH4)2SO4) ao meio NYD e da vazÃo de ar sobre o crescimento da cepa Com os parÃmetros estudados foram determinadas as melhores condiÃÃes para a produÃÃo de Bacillus sp RAB9 / The growth-promoting bacteria in plants (BPCP) represents a functional portion of the active biota soil rhizosphere are present in rhizoplane and within host plants The biotechnological use of these bacteria has intensified in recent years The genus Bacillus has been continually cited in studies related to growth promotion in plant species Some species can be applied as a seed treatment organs for the vegetative propagation and seedling Therefore this study aimed to assess the biomass of Bacillus sp (RAB9) with potential use in promoting growth of banana plantlets The strain Bacillus sp (RAB9) belonging to the group of epiphytic bacteria was isolated from radish from the Culture Collection of the Laboratory of Fitobacteriologia Federal Rural University of Pernambuco The experiments were performed on an orbital shaker and batch reactor In orbital shaker was studied growth curve of strain at 30ÂC to observe their exponential phase For the production of biomass were observed the effects of adding the content of peptone (5 to 50 g.L-1) in NYD medium (meat extract yeast extract meat peptone and dextrose) addition of secondary elements (K2HPO4 and MgSO4) and inorganic nitrogen source ((NH4)2SO4) In batch reactor tests were conducted with different air flows in simple batch and fed batch with a comparison with the modified medium The fermentations presented in the reactors foaming tests were made with vegetable oils (corn canola sunflower soybean) and to verify the best mineral defoamer Later tests were quantified biomass residual sugar residual nitrogen and ammonia nitrogen With the results noted the importance of the addition of elements (MgSO4 and (NH4)2SO4) in half NYD and air flow on the growth of strain With the studied parameters were determined the best conditions for the production of Bacillus sp RAB9
32

Movement of Air Through Submerged Air Vents

woods, Clay W. 01 December 2011 (has links)
A series of physical models consisting of three different diameter pipes at the same 4% slope were studied at the Utah Water Research Laboratory (UWRL). Various combinations of air flow and head on the pipe were used to determine the effect of pipe diameter, head, and air flow on the behavior of air bubbles introduced into the pipes and to determine the venting capacity of the pipes. It was determined that neither bubble velocity nor bubble length changes with pipe diameter or head changes within the range tested. It was also determined that bubble velocity and length will increase with increased air flow. Bubble velocity also increased with increasing bubble length consistent with prior research. Overall the venting capacity of a pipe is dependent upon having a large enough pipe to prevent slug flow. A procedure was developed to aid in the sizing of submerged vent piping during the design of pipelines based on the data collected during this study and utilizing prior research.
33

SATELLITE-BASED APPROACH FOR MONITORING AND MAPPING THE SUBMERGED AQUATIC VEGETATION IN THE EUTROPHIC SHALLOW BASIN OF LAKE BIWA, JAPAN / 琵琶湖の富栄養化浅層湖盆における水生植物のモニタリングおよびマッピングのための衛星データの利用

Yadav, Shweta 25 September 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20694号 / 工博第4391号 / 新制||工||1682(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 米田 稔, 教授 清水 芳久, 准教授 須崎 純一 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
34

Recovery And Restoration Of The Seagrass Halodule Wrightii After Boat Propeller Scar Damage In A Pole-troll Zone In Mosquito Lag

Grablow, Katherine 01 January 2008 (has links)
This study combined documentation of four boat propeller scar types in Halodule wrightii seagrass beds in Mosquito Lagoon, Florida with manipulative field experiments to document scar recovery times with and without restoration. Scar types ranged from the most severe scar type (Type 1) with trench formation which had no roots or shoots in the trench, to the least severe (Type 4) scars that had no depth, intact roots and shoots shorter than the surrounding canopy. For 110 measured existing scars, the frequency of each scar type was 56% for Type 1, 10% for Type 2, 7% for Type 3, and 27% for Type 4. In the first manipulative experiment, experimental scars were created to document the natural recovery time of H. wrightii for each scar severity within one year. Type 4 scars recovered to the control shoot density at 2 months, while Types 1, 2, and 3 scars did not fully recover in one year. Mean estimated recovery for H. wrightii is expected in 25 months for Type 1, and 19 months for Types 2 and 3. For the second manipulative experiment, three restoration methods were tested on the Type 1 scars over a 1 year period. Restoration methods included: (1) planting H. wrightii in the scar trench, (2) filling the trench with sand, and (3) filling with sand plus planting H. wrightii. There was complete mortality of all transplants at 2 months and only 25% of scars retained fill sand after 1 year. With dense adjacent seagrass beds, natural recovery was more successful than any of my restoration attempts. Thus, I suggest that managers should concentrate on preventing seagrass destruction rather than restoration.
35

Fluidelastic Instability of Tube Arrays Subjected to Axisymmetric Jet Flow

Ledger, Buddy 06 1900 (has links)
An experimental scale model study was conducted to investigate the onset of fluidelastic instability in a tube array subjected to axisymmetric jet flow. A tube array was constructed using aluminum tubes with 44.45 mm outer diameter, $D$, which were arranged in a square pattern with 88 mm pitch, $P$. The pitch to diameter ratio, $P/D$, was approximately 2.0. The tubes were flexibly mounted using threaded rod and tuned to a first mode natural frequency, $f_n$, of 9 Hz. Auxiliary damping devices were added to each tube, and tuned, to achieve a damping ratio, $\zeta$, of 1 % of critical. The mass damping parameter, $m(2 \pi \zeta)/(\rho D^{2})$, of the tube array was 27.9. The tube array was tested under uniform flow conditions in McMaster University's 2 ft wind tunnel to establish the critical reduced velocity, $V_{cr}/(f_n D)$, of 30.0 at the onset of fluidelastic instability. The uniform flow test established a basis for comparing the results with the existing literature and evaluating the validity of the proposed partial admission calculation. The tube array was also tested in open air using an axisymmetric jet, with two different physical arrangements, the first with the jet aimed between tubes and perpendicular to the tube spans and the second with the jet aimed at a tube face and perpendicular to the tube spans. In each case the jet flow velocity was incrementally increased to characterize the onset of fluidelastic instability. To characterize the flow dispersion through the tube array a series of velocity profile measurements were also collected. The measured velocity profiles were used to estimate the spanwise function of transverse average gap velocity, $\bar{V}(x)$, which was used to predict the equivalent critical uniform gap flow velocity, $V_{cr}$, using the concept of partial admission. The predicted $V_{cr}$ values showed reasonable agreement with the experimental results. However, the prediction method did indicate instabilities in tube rows where instability was not actually observed. A simplified prediction approach was developed which was based on using a predicted three dimensional velocity profile, $V(x,y)$, at the $z$ location of the first row tube gap, under the assumption of free field conditions, to calculate an estimate of the spanwise function of transverse average gap velocity, $\bar{V}(x)$. Although the predictions of $V_{cr}$ agreed reasonably well with the experimental results, first row instabilities were not observed in any of axisymmetric jet flow experiments. Therefore, this method can be used to estimate the the critical uniform gap velocity, $V_{cr}$, but not the spatial location of the instability. Based on the results of the experiments and calculations, adoption of the modified partial admission formula is recommended and possible avenues for further investigation and verification are suggested. / Thesis / Master of Applied Science (MASc)
36

Experimental Investigation of Aperiodic Bubbling from Submerged Capillary-tube Orifices in Liquid Pools

Gopal, Vignesh 21 October 2013 (has links)
No description available.
37

Submerged flexible vegetation impact on open channel flow velocity distribution: An analytical modelling study on drag and friction

Pu, Jaan H., Hussain, Awesar, Guo, Yakun, Vardakastanis, Nikolaos, Hanmaiahgari, P.R., Lam, Dennis 06 June 2019 (has links)
Yes / In this paper, an analytical model that represents the streamwise velocity distribution for open channel flow with submerged flexible vegetation is studied. In the present vegetated flow modelling, the whole flow field has been separated into two layers vertically: a vegetated layer and a non-vegetated free-water layer. Within the vegetated layer, an analysis of the mechanisms affecting water flow through flexible vegetation has been conducted. In the non-vegetated layer, a modified log-law equation that represents the velocity profile varying with vegetation height has been investigated. Based on the studied analytical model, a sensitivity analysis has been conducted to assess the influences of the drag and friction coefficients on the flow velocity. The investigated ranges of drag and friction coefficients have also been compared to published values. The findings suggest that the drag and friction coefficient values are non-constant at different depths and vegetation densities, unlike the constant values commonly suggested in literature. This phenomenon is particularly clear for flows with flexible vegetation, which is characterised by large deflection.
38

Drag coefficient modelling study for flexible vegetation in open channel flow

Hussain, Awesar, Pu, Jaan H., Hanmaiahgari, P.R. 10 November 2018 (has links)
No / Vegetation remains to be an important factor that can hinder the river flow. It needs innovative management scheme, in order to adapt these changes and ensure sustainability of their multiple usages. Vegetation plays an important role in floods and droughts adaptation within river system to alleviate any flood that may propagates from river to its surrounding. Vegetation within river can also retard its flow to cause building-up of deposition, and further adding to uncertainty of water use under extreme droughts. Due to these, it is important to study and understand vegetation drag behaviour toward flow in order to prevent flood risk and water security with hydrological drought in the basin and any other negative impact caused by it. In this study, an analytical approach for river flooding has been studied by improved representation of drag coefficient CD in flow velocity distribution modelling. The analysis of flow parameters, i.e. Reynolds number, on the drag coefficient CD has been conducted. The presented model has been used and analysed in open channel flows with flexible vegetation. In modelling, the flexible vegetated channel layers were divided into vegetation, top of vegetation and water layer zones in the model. The balance of forces for each layer has been established by validation using different reported measured data. The modelling results showed reasonably corresponding prediction of velocity profile in flows with flexible vegetation.
39

The application of extensive 3D Seismic Reflection Data for the exploration of extensive inundated Palaeolandscapes

Fitch, Simon, Gaffney, Vincent January 2013 (has links)
Yes
40

A needle in a haystack: Landscape survey and archaeological detection experiments in Apalachee Bay

Fitch, Simon, Cook Hale, Jessica 16 August 2024 (has links)
This paper presents the results of a pilot landscape-scale seismic survey undertaken in Apalachee Bay, Florida, across a submerged landscape that contains dozens of Pre-Contact sites. In addition to the goals of improving the geophysical and remote sensing ground model for this submerged landscape, the survey also sought to undertake the first independent scientific test of the contentious ‘HALD’ methodology, an acoustic resonance method that it is claimed to identify knapped lithic artefacts at and/ or below the seabed through the identification of distinct ‘haystack’ responses. The results of this work indicate that the HALD method, as currently described, produces results that could not be scientifically replicated in this survey. We conclude that any HALD ‘haystack’ signal should therefore not be considered as an example of detection of human-modified lithic material but rather as a geophysical anomaly that requires additional constraints before it can be used to reliably identify human-modified lithic materials. Thus, although the authors note that laboratory studies have successfully produced an acoustic signal in human-modified lithics, the field-based methods remain yet to be reliably determined. In addition to these results, the landscape mapping survey also recorded valuable information on buried and previously unrecorded landscape features that have archaeological significance and that may guide future site prospection. We therefore conclude that despite the results of the HALD test, the well-preserved submerged landscape of Apalachee Bay region provides a highly useful testing ground for methods that can be deployed elsewhere globally. / UK Research and Innovation (UKRI) for the Life on the Edge Project (LOTE) via a UKRI Future Leaders Fellowship (Grant No. MR/W007797/1).

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