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Tesi sul tema "Salinity"
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1
Sanoubar, Rabab <1971>. "Salinity Effect on Horticultural Crops: Morphological, Physiological, and Biomolecular Elements of Salinity Stress Response". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6645/1/Sanoubar_Rabab_Tesi.pdf.
Testo completoAbstract (sommario):
Among abiotic stresses, high salinity stress is the most severe environmental stress. High salinity exerts its negative impact mainly by disrupting the ionic and osmotic equilibrium of the cell. In saline soils, high levels of sodium ions lead to plant growth inhibition and even death. Salt tolerance in plants is a multifarious phenomenon involving a variety of changes at molecular, organelle, cellular, tissue as well as whole plant level. In addition, salt tolerant plants show a range of adaptations not only in morphological or structural features but also in metabolic and physiological processes that enable them to survive under extreme saline environments. The main objectives of my dissertation were understanding the main physiological and biomolecular features of plant responses to salinity in different genotypes of horticultural crops that are belonging to different families Solanaceae (tomato) and Cucurbitaceae (melon) and Brassicaceae (cabbage and radish). Several aspects of crop responses to salinity have been addressed with the final aim of combining elements of functional stress response in plants by using several ways for the assessment of plant stress perception that ranging from destructive measurements (eg. leaf area, relative growth rate, leaf area index, and total plant fresh and dry weight), to physiological determinations (eg. stomatal conductance, leaf gas exchanges, water use efficiency, and leaf water relation), to the determination of metabolite accumulation in plant tissue (eg. Proline and protein) as well as evaluation the role of enzymatic antioxidant capacity assay in scavenging reactive oxygen species that have been generated under salinized condition, and finally assessing the gene induction and up-down regulation upon salinization (eg. SOS pathway).
2
Sanoubar, Rabab <1971>. "Salinity Effect on Horticultural Crops: Morphological, Physiological, and Biomolecular Elements of Salinity Stress Response". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6645/.
Testo completoAbstract (sommario):
Among abiotic stresses, high salinity stress is the most severe environmental stress. High salinity exerts its negative impact mainly by disrupting the ionic and osmotic equilibrium of the cell. In saline soils, high levels of sodium ions lead to plant growth inhibition and even death. Salt tolerance in plants is a multifarious phenomenon involving a variety of changes at molecular, organelle, cellular, tissue as well as whole plant level. In addition, salt tolerant plants show a range of adaptations not only in morphological or structural features but also in metabolic and physiological processes that enable them to survive under extreme saline environments. The main objectives of my dissertation were understanding the main physiological and biomolecular features of plant responses to salinity in different genotypes of horticultural crops that are belonging to different families Solanaceae (tomato) and Cucurbitaceae (melon) and Brassicaceae (cabbage and radish). Several aspects of crop responses to salinity have been addressed with the final aim of combining elements of functional stress response in plants by using several ways for the assessment of plant stress perception that ranging from destructive measurements (eg. leaf area, relative growth rate, leaf area index, and total plant fresh and dry weight), to physiological determinations (eg. stomatal conductance, leaf gas exchanges, water use efficiency, and leaf water relation), to the determination of metabolite accumulation in plant tissue (eg. Proline and protein) as well as evaluation the role of enzymatic antioxidant capacity assay in scavenging reactive oxygen species that have been generated under salinized condition, and finally assessing the gene induction and up-down regulation upon salinization (eg. SOS pathway).
3
Farr, C. R. "Salinity Distribution Under Drip Irrigation". College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/204075.
Testo completo
4
Hick, Peter T. "Remote sensing of agricultural salinity". Thesis, Curtin University, 1987. http://hdl.handle.net/20.500.11937/877.
Testo completoAbstract (sommario):
Salinity represents the major environmental threat to arable land in Western Australia and many other parts of the world. This study was designed to establish criteria for a practical remote sensing system using the visible, reflected and shortwave infrared for the early detection and mapping of salinity. The results are principally from a group of study sites on the CSIROs Yalanbee Experiment Station, and from other significant sites during the agricultural cycles of 1985-7.Analysis of imagery from the Geoscan Multispectral Airborne Scanner showed that best discrimination between study sites affected by salinity, and those not affected, was provided by bands 3 (650-700 nm), 4 (830-870nm) and band 6 (1980-2080nm). The maximum discrimination occurred in a September 1986 flight (spring-flush). Although excellent discrimination was also evident in August and November in 1985, this could not be reproduced in November 1986. The visible and reflected infrared bands 3 and 4 featured prominently, but the significance of the short wave infrared bands was evident especially when vegetative ground cover became a less dominant factor.Field spectra collected over the same period with the Geoscan Portable Field Spectroradiometer (PFS) supported the aircraft data to a certain extent. Detailed analysis of the fine non-correlated structure of narrow constructed bands, from PFS data, indicated that improved discrimination between sites could be provided over a wider time window extending into the summer and autumn. This is when weather-related conditions, i.e. cloud, soil moisture and sun angle, are more conducive to extensive surveys.The importance of at least one narrow band centred near 1985 nm was determined. Laboratory spectra of bare soil from sites measured on an Hitachi Spectrophotometer also provided the importance of the shortwave region adjacent to the 1900 nm water absorption.The study evaluated the spatial and spectral characteristics of existing satellite systems such as Thematic Mapper and the Multispectral Scanner on the Landsat series and determined that a spatial resolution of about 20-30 metres was most appropriate for detection of salinity at a scale whereby management could be implemented.Ground electromagnetic techniques were evaluated during the study and the EM-38 Ground Conductivity Unit proved valuable for characterizing salinity status of the sites. The Lowtran Computer Code was used to model atmospheric attenuation and results indicated that the positioning of a narrow shortwave infrared waveband, centred at 1985 nm, is possible.
5
Hick, Peter T. "Remote sensing of agricultural salinity". Curtin University of Technology, Department of Environmental Biology, 1987. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=10930.
Testo completoAbstract (sommario):
Salinity represents the major environmental threat to arable land in Western Australia and many other parts of the world. This study was designed to establish criteria for a practical remote sensing system using the visible, reflected and shortwave infrared for the early detection and mapping of salinity. The results are principally from a group of study sites on the CSIROs Yalanbee Experiment Station, and from other significant sites during the agricultural cycles of 1985-7.Analysis of imagery from the Geoscan Multispectral Airborne Scanner showed that best discrimination between study sites affected by salinity, and those not affected, was provided by bands 3 (650-700 nm), 4 (830-870nm) and band 6 (1980-2080nm). The maximum discrimination occurred in a September 1986 flight (spring-flush). Although excellent discrimination was also evident in August and November in 1985, this could not be reproduced in November 1986. The visible and reflected infrared bands 3 and 4 featured prominently, but the significance of the short wave infrared bands was evident especially when vegetative ground cover became a less dominant factor.Field spectra collected over the same period with the Geoscan Portable Field Spectroradiometer (PFS) supported the aircraft data to a certain extent. Detailed analysis of the fine non-correlated structure of narrow constructed bands, from PFS data, indicated that improved discrimination between sites could be provided over a wider time window extending into the summer and autumn. This is when weather-related conditions, i.e. cloud, soil moisture and sun angle, are more conducive to extensive surveys.The importance of at least one narrow band centred near 1985 nm was determined. Laboratory spectra of bare soil from sites measured on an Hitachi Spectrophotometer also provided the importance of the shortwave region adjacent to the 1900 nm water ++absorption.The study evaluated the spatial and spectral characteristics of existing satellite systems such as Thematic Mapper and the Multispectral Scanner on the Landsat series and determined that a spatial resolution of about 20-30 metres was most appropriate for detection of salinity at a scale whereby management could be implemented.Ground electromagnetic techniques were evaluated during the study and the EM-38 Ground Conductivity Unit proved valuable for characterizing salinity status of the sites. The Lowtran Computer Code was used to model atmospheric attenuation and results indicated that the positioning of a narrow shortwave infrared waveband, centred at 1985 nm, is possible.
6
Sabia, Roberto. "Sea surface salinity retrieval error budget within the esa soil moisture and ocean salinity mission". Doctoral thesis, Universitat Politècnica de Catalunya, 2008. http://hdl.handle.net/10803/30542.
Testo completoAbstract (sommario):
L’oceanografia per satèl•lit ha esdevingut una integració consolidada de les tècniques convencionals de monitorització in situ dels oceans. Un coneixement precís dels processos oceanogràfics i de la seva interacció és fonamental per tal d’entendre el sistema climàtic. En aquest context, els camps de salinitat mesurats regularment constituiran directament una ajuda per a la caracterització de les variacions de la circulació oceànica global. La salinitat s’utilitza en models oceanogràfics predictius, pero a hores d’ara no és possible mesurar-la directament i de forma global.
La missió Soil Moisture and Ocean Salinity (SMOS) (en català, humitat del sòl i salinitat de l’oceà) de l’Agència Espacial Europea pretén omplir aquest buit mitjançant la implementació d’un satèl•lit capaç de proveir aquesta informació sinòpticament i regular.
Un nou instrument, el Microwave Imaging Radiometer by Aperture Synthesis (MIRAS) (en català, radiòmetre d’observació per microones per síntesi d’obertura), ha estat desenvolupat per tal d’observar la salinitat de la superfície del mar (SSS) als oceans a través de l’adquisició d’imatges de la radiació de microones emesa al voltant de la freqüència de 1.4 GHz (banda L). SMOS portarà el primer radiòmetre orbital, d’òrbita polar, interferomètric 2D i es llençarà a principis de 2009.
Així com a qualsevol altra estimació de paràmetres geofísics per teledetecció, la recuperació de la salinitat és un problema invers que implica la minimització d’una funció de cost. Per tal d’assegurar una estimació fiable d’aquesta variable, la resta de paràmetres que afecten a la temperatura de brillantor mesurada s’ha de tenir en compte, filtrar o quantificar. El producte recuperat seran doncs els mapes de salinitat per a cada passada del satèl•lit sobre la Terra.
El requeriment de precisió proposat per a la missió és de 0.1 ‰ després de fer el promig en finestres espaciotemporals de 10 dies i de 20x20.
En aquesta tesi de doctorat, diversos estudis s’han dut a terme per a la determinació del balanç d’error de la salinitat de l’oceà en el marc de la missió SMOS. Les motivacions de la missió, les condicions de mesura i els conceptes bàsics de radiometria per microones es descriuen conjuntament amb les principals característiques de la recuperació de la salinitat.
Els aspectes de la recuperació de la salinitat que tenen una influència crítica en el procés d’inversió són:
• El biaix depenent de l’escena en les mesures simulades,
• La sensibilitat radiomètrica (soroll termal) i la precisió radiomètrica,
• La definició de la modelització directa banda L
• Dades auxiliars, temperatura de la superfície del mar (SST) i velocitat del vent, incerteses,
• Restriccions en la funció de cost, particularment en el terme de salinitat, i
• Promig espacio-temporal adequat.
Un concepte emergeix directament de l’enunciat del problema de recuperació de la salinitat: diferents ajustos de l’algoritme de minimització donen resultats diferents i això s’ha de tenir en compte. Basant-se en aquesta consideració, la determinació del balanç d’error s’ha aproximat progressivament tot avaluant l’extensió de l’impacte de les diferents variables, així com la parametrització en termes d’error de salinitat.
S’ha estudiat l’impacte de diverses dades auxiliars provinents de fonts diferents sobre l’error SSS final. Això permet tenir una primera impressió de l’error quantitatiu que pot esperar-se en les mesures reals futures, mentre que, en un
altre estudi, s’ha investigat la possibilitat d’utilitzar senyals derivats de la reflectometria per tal de corregir les incerteses de l’estat del mar en el context SMOS.
El nucli d’aquest treball el constitueix el Balanç d’Error SSS total. S’han identificat de forma consistent les fonts d’error i s’han analitzat els efectes corresponents en termes de l’error SSS mig en diferents configuracions
d’algoritmes.
Per una altra banda, es mostren els resultats d’un estudi de la variabilitat horitzontal de la salinitat, dut a terme utilitzant dades d’entrada amb una resolució espacial variable creixent. Això hauria de permetre confirmar la capacitat de la SSS recuperada per tal reproduir característiques oceanogràfiques mesoscàliques.
Els principals resultats i consideracions derivats d’aquest estudi contribuiran a la definició de les bases de l’algoritme de recuperació de la salinitat.Satellite oceanography has become a consolidated integration of conventional in situ monitoring of the oceans. Accurate knowledge of the oceanographic processes and their interaction is crucial for the understanding of the climate system. In this framework, routinely-measured salinity fields will directly aid in characterizing the variations of the global ocean circulation. Salinity is used in predictive oceanographic models, but no capability exists to date to measure it directly and globally. The European Space Agency’s Soil Moisture and Ocean Salinity (SMOS) mission aims at filling this gap through the implementation of a satellite that has the potential to provide synoptically and routinely this information. A novel instrument, the Microwave Imaging Radiometer by Aperture Synthesis, has been developed to observe the sea surface salinity (SSS) over the oceans by capturing images of the emitted microwave radiation around the frequency of 1.4 GHz (L-band). SMOS will carry the first-ever, polar-orbiting, space-borne, 2-D interferometric radiometer and will be launched in early 2009. Like whatsoever remotely-sensed geophysical parameter estimation, the retrieval of salinity is an inverse problem that involves the minimization of a cost function. In order to ensure a reliable estimation of this variable, all the other parameters affecting the measured brightness temperature will have to be taken into account, filtered or quantified. The overall retrieved product will thus be salinity maps in a single satellite overpass over the Earth. The proposed accuracy requirement for the mission is specified as 0.1 ‰ after averaging in a 10-day and 2ºx2º spatio-temporal boxes. In this Ph.D. Thesis several studies have been performed towards the determination of an ocean salinity error budget within the SMOS mission. The motivations of the mission, the rationale of the measurements and the basic concepts of microwave radiometry have been described along with the salinity retrieval main features. The salinity retrieval issues whose influence is critical in the inversion procedure are: • Scene-dependent bias in the simulated measurements, • Radiometric sensitivity (thermal noise) and radiometric accuracy, • L-band forward modeling definition, • Auxiliary data, sea surface temperature (SST) and wind speed, uncertainties, • Constraints in the cost function, especially on salinity term, and • Adequate spatio-temporal averaging. A straightforward concept stems from the statement of the salinity retrieval problem: different tuning and setting of the minimization algorithm lead to different results, and complete awareness of that should be assumed. Based on this consideration, the error budget determination has been progressively approached by evaluating the extent of the impact of different variables and parameterizations in terms of salinity error. The impact of several multi-sources auxiliary data on the final SSS error has been addressed. This gives a first feeling of the quantitative error that should be expected in real upcoming measurements, whilst, in another study, the potential use of reflectometry-derived signals to correct for sea state uncertainty in the SMOS context has been investigated. The core of the work concerned the overall SSS Error Budget. The error sources are consistently binned and the corresponding effects in terms of the averaged SSS error have been addressed in different algorithm configurations. Furthermore, the results of a salinity horizontal variability study, performed by using input data at increasingly variable spatial resolution, are shown. This should assess the capability of retrieved SSS to reproduce mesoscale oceanographic features. Main results and insights deriving from these studies will contribute to the definition of the salinity retrieval algorithm baseline.
7
Ha, Mi Ae. "Salinity routing in reservoir system modeling". Thesis, Texas A&M University, 2006. http://hdl.handle.net/1969.1/4963.
Testo completoAbstract (sommario):
This research evaluates and improves capabilities incorporated in the Water Rights Analysis Package (WRAP) modeling system for tracking salt loads, particularly for applications dealing with natural salt pollution problems that are prevalent in several major river basins in Texas and neighboring states. WRAP is the river/reservoir system simulation model incorporated in the Water Availability Modeling (WAM) System applied by agencies and consulting firms in Texas in planning and water right regulatory activities. A salinity simulation component of WRAP called WRAP-SALT was developed recently at Texas A&M University. WRAP-SALT was based on the premise of complete mixing within the monthly computational time step. However, salt concentrations actually have time variation throughout a reservoir. This thesis research investigates more realistic salinity routing methods. Historical gauged data provide a basis for calibration of routing parameters. The timing of the inflow load to determine outflow concentration is calculated by lag parameters with the monthly time steps. Complete mixing occurs during the lag months. Two options are incorporated into WRAP-SALT for setting the lag parameter. With the first option, the model-user sets a constant that is applied during every month of the simulation. This option requires calibration studies to determine the lag. With the alternative option, a variable lag is computed within the model in each month based on the concept of retention time, which is a representation of the time required for a monthly volume of water and its salt load to flow through a reservoir. When the lag is activated, the accuracy between observed and computed mean monthly salinity concentrations through the reservoir is generally improved. The basin-wide simulation was performed for the Brazos River Basin for conditions with and without salt control dams proposed by the Corps of Engineers. The proposed salt control impoundments improve water quality throughout the basin.
8
Elmezoghi, Saleh Mohamed. "Physiology of salinity tolerance in maize". Thesis, University of Liverpool, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433774.
Testo completo
9
Babagolzadeh, Ali. "Salinity tolerance in seven Trifolium species". Thesis, University of Liverpool, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367195.
Testo completo
10
Hossain, Mohammad Rashed. "Salinity tolerance and transcriptomics in rice". Thesis, University of Birmingham, 2014. http://etheses.bham.ac.uk//id/eprint/5092/.
Testo completoAbstract (sommario):
Morpho-physiological characterization and whole genome transcript profiling of rice genotypes that belongs to sub-species Indica, Japonica and wild relatives were carried out under salt stress. The existence of qualitatively different mechanisms of salt tolerance across the genotypes was identified. Multivariate analysis was applied to categorize the genotypes according to their level of tolerance. Modified SAM analysis elucidated the trait specific expression of genome wide transcripts. Gene ontology enrichment analysis identified the genes involved in different molecular functions such as signal transduction, transcription factor and ion homeostasis etc. Gene network analysis identified the regulatory network of genes that are active in different tissues. The differential expression of transcripts of four tolerant and two susceptible Indica genotypes under stress were further analysed. The candidate genes for different biological processes and molecular functions are identified and discussed. Highly induced stimulus responsive gene Os01g0159600 (OsLEA1a) and Os05g0382200 (Nhx) can be mentioned for instance. The differentially expressed genes that are located within the salt stress related QTLs were also identified. The transcriptomics data were also used to predict the salinity tolerance of genotypes using OSC-PLSDA model. The combined physiological and transcriptomic approach of this study gives a complementary whole organism assessment of plants responses to salt stress.
11
Chung, Hyung Won. "Membrane distillation for high salinity desalination". Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/100061.
Testo completoAbstract (sommario):
Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2015.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references (pages 57-60).
Membrane distillation systems typically have low energy efficiency. Multistage membrane distillation (MD) systems can have significantly higher efficiencies than their single stage counterparts. However, multistage MD system design has received limited attention. In this work, the performance of a multistage vacuum membrane distillation (MSVMD) which is thermodynamically similar to a multi-stage flash distillation (MSF) is evaluated for desalination, brine concentration, and produced water reclamation applications. A wide range of solution concentrations were accurately modeled by implementing Pitzer's equations for NaCl-solution properties. The viability of MSVMD use for zero liquid discharge (ZLD) applications is investigated, by considering discharge salinities close to NaCl saturation conditions. Energy efficiency (gained output ratio or GOR), second law efficiency, and the specific membrane area were used to quantify the performance of the system. At high salinities, the increased boiling point elevation of the feed stream resulted in lower fluxes, larger heating requirements and lower GOR values. The second law efficiency, however, is higher under these conditions since the least heat for separation increases faster than the system's specific energy consumption with increase in salinity. Under high salinity conditions, the relative significance of irreversible losses is lower. Results indicate that MSVMD systems can be as efficient as a conventional MSF system, while using reasonable membrane areas and for a wide range of feed salinities. Given MD's advantages over MSF such as lower capital requirement and scalability, MSVMD can be an attractive alternative to conventional thermal desalination systems. Recently proposed single stage MD systems have shown high energy efficiency. Permeate gap (PGMD) and conductive gap (CGMD) systems are studied in the context of energy efficiency. A wide range of salinities was considered to investigate potential of these single stage systems for high salinity desalination applications.
by Hyung Won Chung.
S.M.
12
Schuch, Ursula K., e Jack J. Kelly. "Salinity Tolerance of Cacti and Succulents". College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2008. http://hdl.handle.net/10150/216639.
Testo completoAbstract (sommario):
The salinity tolerance of golden barrel cactus (Echinocactus grusonii), ocotillo (Fouquieria splendens), saguaro cactus (Carnegiea gigantea), and Gentry’s agave (Agave parryi truncata) was tested. Plants were irrigated with a solution of EC 0.6, 5.0, 10.0, and 15.0 dS/m. Duration of treatments were 18 weeks for saguaro and 26 weeks for the other three species. In general, fresh weight, dry weight, and moisture content decreased with increasing salinity levels, with the exception of saguaro dry weight which was not affected by the treatments, and ocotillo moisture content which increased with increasing salinity. Runoff was collected three times during the experiment and indicated that ion uptake was higher for barrel cactus than the other three species. EC of runoff averaged for all dates and species showed an increase of 17%, 54%, 46%, and 64% over the salinity treatment solutions of 0.6, 5.0, 10.0, and 15.0 dS/m, respectively.
13
Kandjou, Kaunahama. "Effect of salinity on oxygen consumption and growth of juvenile white steenbras, litohognathus lithognathus". Thesis, Rhodes University, 2008. http://eprints.ru.ac.za/1705/.
Testo completo
14
Talone, Marco. "Contributrion to the improvement of the soil moisture and ocean salinity (SMOS) sea surface salinity retrieval algorithm". Doctoral thesis, Universitat Politècnica de Catalunya, 2010. http://hdl.handle.net/10803/48633.
Testo completoAbstract (sommario):
The European Space Agency's Soil Moisture and Ocean Salinity (SMOS)
satellite was launched on November, 2, 2009 from the Russian cosmodrome
of Plesetsk. Its objective is to globally and regularly collect measurements of
soil moistre and Sea Surface Salinity (SSS). To do that, a pioneering instru-
ment has been developed: the Microwave Imaging Radiometer by Aperture
Synthesis (MIRAS), the rst space-borne, 2-D interferometric radiometer
ever built; it operates at L-band, with a central frequency of 1.4135 GHz,
and consists of 69 antennas arranged in a Y shape array. MIRAS' output
are brightness temperature maps, from which SSS can be derived through
an iterative algorithm, and using auxiliary information. For each overpass
of the satellite an SSS map is produced, with an estimated accuracy of 1
psu (rmse). According to the Global Ocean Data Assimilation Experiment
(GODAE) the mission requirement is instead speci ed as 0.1 psu after av-
eraging in a 10-day and 2 2 spatio-temporal boxes.
In previuos works ((Sabia et al., 2010), or more extensively in Dr. Sabia's
Ph.D. thesis (Sabia, 2008)) the main error sources in retrieving SSS from
SMOS measurements were determined as:
1. Scene-dependent bias in the simulated measurements,
2. L-band forward modeling de nition,
3. Radiometric sensitivity and accuracy,
4. Constraints in the cost function, and
5. Spatio-temporal averaging.
This Ph.D. thesis, is an attempt of reducing part of the aforementioned
errors (the relative to the one-overpass SSS (1 - 4)) by a more sophisticated
data processing.
Firstly, quasi-realistic brightness temperatures have been simulated using
the SMOS End-to-end Performance Simulator (SEPS) in its full mode and
an ocean model, as provider for geophysical parameters. Using this data
set the External Brightness Temperature Calibration technique has been
tested to mitigate the scene-dependent bias, while the error introduced by
inaccuracies in the L-band forward models has been accounted for by the
application of the External Sea Surface Salinity Calibration.
Apart from simulated brightness temperatures, both External Brightness
Temperature Calibration and External Sea Surface Salinity Calibration have
been tested using real synthetic-aperture brightness temperatures, collected
by the Helsinki University of Technology HUT-2D radiometer during the
SMOS Calibration and Validation Rehearsal Campaign in August 2007 and
ten days of data acquired by the SMOS satellite between July 10 and 19,
2010.
Finally, a study of the cost function used to derive SSS has been performed:
the correlation between measurement mis ts has been estimated and the
e ect of including it in the processing have been assessed.
As an outcome of a 3-month internship at the Laboratoire LOCEAN in
Paris, France, a theoretical review of the e ect of the rain on the very top
SSS vertical pro le has been carried out and is presented as Appendix.
15
Stong, Matthew Harold. "Development of Remote Sensing Techniques for Assessment of Salinity Induced Plant Stresses". Diss., The University of Arizona, 2008. http://hdl.handle.net/10150/194858.
Testo completoAbstract (sommario):
Salinity has been shown to reduce vegetative growth, crop quality, and yield in agricultural crops. Remote sensing is capable of providing data about large areas. This project was designed to induce salinity stress in a crop, pak choi, and thereafter monitor the response of the crop as expressed by its spectral reflectances. The project was conducted in the National Taiwan University Phytotron, and spectral data was collected using a GER 2600. Yield and soil salinity (ECe) were also measured. After three seasons of data were collected, wavelengths sensitive to salinity were selected. These wavelengths, which are within the spectral response of biochemicals produced by plants as a response to soil salinity, were used to create two indices, the Salinity Stress Index (SSI) and the Normalized Salinity Stress Index (NSSI). After creating the indices tests were conducted to determine the efficacy of these indices in detecting salinity and drought stresses as compared to existing indices (SRVI and NDVI). This project induced salinity and drought stress in a crop, pak choi, and thereafter monitored the response of the crop as expressed by its spectral reflectances. The SSI and NSSI correlated well to both ECe and marketable yield. Additionally the SSI and NSSI were found to provide statistical differences between salinity stressed treatments and the control treatment. Drought stress was not detected well by any of the indices reviewed although the SSI and NSSI indices tended to increase with drought stress and decrease with salinity stress. As a final test, specific ion toxicities of sodium and chloride were tested against the developed indices (SSI and NSSI) and existing indices (NDVI, SRVI, and NDWI). There were no differences in SSI and NSSI responses to specific ion concentration in the high salinity treatments. These results indicated that the SSI and NSSI are not sensitive to the specific ion concentration in irrigation water. However, the SSI and NSSI were higher for the sodium water than the choride water in the low salinity treatments. It is likely that this difference was caused by the fact that the high SAR water decreased infiltration and caused water stress.
16
Fournier, Séverine. "Spatio-temporal coherence between spaceborne measurements of salinity and optical properties in the Amazon-Orinoco Plume Region". Thesis, Brest, 2014. http://www.theses.fr/2014BRES0071/document.
Testo completoAbstract (sommario):
Avec les lancements réussis des missions ESA Soil Moisture and Ocean Salinity (SMOS) et NASA Aquarius/SAC-D, la salinité de surface des océans peut maintenant être déduite. De plus, les produits de couleur de l'eau, tels que les mesures d'absorption et d'atténuation de la lumière et de concentration en chlorophylle, peuvent être utilisés comme traceurs de la salinité. Les signatures des panaches des grands fleuves tropicaux tels que l'Amazone et l'Orénoque peuvent être étudiées en détail grâce à ces nouvelles méthodes. En particulier, les relations de corrélations entre SSS et propriétés optiques également déduites de mesures satellites peuvent maintenant être établies et analysées sur des échelles spatiales beaucoup plus grandes. Différents efforts de recherche sont envisagés dans le cadre de ce travail de thèse. Tout d'abord, nous étudions les corrélations entre salinité de surface et propriétés optiques dans le panache de l'Amazone durant la période 2010-2013. Ensuite, la relation de mélange est établie de façon robuste selon tout d'abord une approche régionale, puis selon une approche locale. Ensuite, une fois cette loi de dilution établie de façon robuste, nous l'utilisons pour estimer un produit de salinité de surface à partir des produits couleur de l'eau sur la période 1998-2013. Enfin, nous tentons d'envisager la relation de dilution suivant une approche lagrangienneWe enter now in a new era of global Sea Surface Salinity (SSS) observing systems from Space with therecent successful launches of the ESA Soil Moisture and Ocean Salinity (SMOS) mission and the NASA Aquarius/SAC-D mission. These new satellite SSS observing systems are as well complemented by an increased number of devices deployed in situ. Finally, ocean color products can be used as well for tracking salinity via semi-conservative tracers such as dissolved organic matter absorption coefficient at 443 nm(acdm), light attenuation at 490 nm and chlorophyll concentration. With these new methods, we are now in an excellent position to revisit the SSS observed in the warm seas of the tropical Atlantic with multi-yeartime series of excellent remote sensing and concurrent in situ observations. The seasonal cycles in the spatial extent of low surface salinity waters of the major river plumes and freshwater pools of the tropical Atlantic oceans as the Amazon and Orinoco rivers can thus be analyzed in a new and original manner. In particular, the correlation between SSS and bio-optical properties measured from Space in the plume waters can now beestablished and analyzed over large spatial scales. In the frame of this PhD work, different major research topics were studied. First the correlations between sea surface salinity and absorption coefficient of colored detrital matter at 443 nm in the Amazon-Orinoco plume over 2010-2013 are studied. Then the conservative mixing relationship is robustely established based on two different approaches, a regional one over the whole Amazon plume and a local one. Once the SSS/acdm relationship established, it is used to retrieve a SSSproduct from 1998 to 2013 based on Ocean Color data. Finally, we attempt to explore the conservative mixing using a lagrangian approach
17
Taylor, Peter John. "Potential impacts of interception belts on the management of dryland salinity /". Title page, contents and abstract only, 1999. http://web4.library.adelaide.edu.au/theses/09AGRP/09agrpt245.pdf.
Testo completo
18
Hendawy, Salah El-Sayed el. "Salinity tolerance in Egyptian spring wheat genotypes". [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972317627.
Testo completo
19
Krishnamurthy, Ganesh. "Incorporating salinity considerations in water availability modeling". Texas A&M University, 2006. http://hdl.handle.net/1969.1/3833.
Testo completoAbstract (sommario):
This research focused on expanding the capabilities of the Water Rights Analysis
Package (WRAP) for incorporating salinity considerations in assessments of water
availability. A simulation modeling approach was used to address this issue and a
generalized simulation model called WRAP-SALT was developed. The Brazos River
Basin served as a case study to test the simulation approach adopted by the model.
The simulation model adopts a generalized modeling approach applicable to any
river basin system. The model tracks salinity throughout a river basin system over
different periods of time for alternative scenarios of water use, reservoir system
operating policies, and salt control mechanisms. The model was applied to the Brazos
River Basin considering different management scenarios and the results obtained were
analyzed.
Reservoir reliabilities were assessed under user imposed salinity constraints. It
was observed that the water supply reliabilities decreased significantly if salinity
constraints were considered. Salt control dams proposed by the U.S. Army Corps of Engineers were also incorporated in the simulation of the river basin. It was observed
that salinity in the main stem of the Brazos River was significantly reduced. However,
no significant improvement was observed in water supply reliabilities.
20
Whittington, John. "Physiological effects of salinity on chara corallina /". Title page, contents and summary only, 1990. http://web4.library.adelaide.edu.au/theses/09PH/09phw6258.pdf.
Testo completo
21
Memon, Jawed Akhtar. "Interaction between salinity and nutrients in cotton". Thesis, Bangor University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297670.
Testo completo
22
Turhan, Hakan. "Salinity studies in potato (Solanum tuberosum L.)". Thesis, University of Reading, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363437.
Testo completo
23
ConceiÃÃo, Susana Silva. "ACCLIMATIZATION SUNFLOWER PLANTS TO SALINITY INDUCED SILICON". Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=16360.
Testo completoAbstract (sommario):
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoThe aim of the study was to evaluate the effects of silicon (Si) in sunflower plants subjected to salinity, studying physiological and biochemical mechanisms of the plant. Sunflower seeds (cv. Catissol 01) were sown in polystyrene trays containing a mixture of sands (washed with water and sterilized by autoclaving) and vermiculite, conducted in the greenhouse. In 7th days after sowing (DAS), the seedlings were transferred to pots containing the nutrient solution of Hoagland. The beginning of the treatments occurred at 28th DAS, and evaluations of plants were carried out 14th days later. It used a factorial scheme 4 Ã 4, in a randomized design, with four replications, in which the factors consisted of four Si concentrations (0.0; 1.0; 1.5; and 2.0 mM) and four NaCl concentrations (0; 50; 100; and 150 mM). The salinity influenced the decrease in height and the dry matter of sunflower plants, but the presence of Si reversed this effect, resulting in taller plants and increased dry matter, compared to those not treated with this nutrient, even when subjected to saline stress conditions. As well as treatment with Siinduced lower electrolyte leakage in leaf and root tissues and higher relative water content in the leaves of plants subjected to saline stress conditions, possibly, caused by the accumulation of silica crystals in these plant tissues. The increase in Si concentrations induced the accumulation of soluble proteins, proline, and N-amino solutes in leaf and root tissues, and this result is related to the higher nitrate content and higher activity of nitrate reductase in the leaves and roots of plants treated with silicon. Oxidative damage in leaves and roots of sunflower plants were partially reduced by treatment with Si. In general, the activity of the enzyme superoxide dismutase, ascorbate peroxidase and catalase was increased in plants subjected to saline stress conditions and treated with Si. Thus, the application of Si in vegetative growth decreased the effects of salinity on sunflower plants, especially, using higher concentrations of silicon (2 mM), allowing the plants to properly acclimate conditions of saline stress, through improvements in the relative water content of the plant, the accumulation of organic solutes and an antioxidant enzyme system more efficient.
Este trabalho teve como objetivo avaliar os efeitos do silÃcio (Si) em plantas de girassol submetidas à salinidade, estudando mecanismos fisiolÃgicos e bioquÃmicos envolvidos. Para isso, sementes de girassol (cultivar Catissol 01) foram semeadas em bandejas de polietileno contendo uma mistura de areia lavada autoclavada e vermiculita, sendo mantidas em casa de vegetaÃÃo. Sete dias apÃs a semeadura (DAS), as plÃntulas foram transferidas para vasos com soluÃÃo nutritiva de Hoagland. O inÃcio dos tratamentos ocorreu aos 28 DAS e a coleta das plantas foi realizada 14 dias depois. Foi utilizado um esquema fatorial 4 à 4, em delineamento inteiramente casualizado, com quatro repetiÃÃes, sendo os fatores constituÃdos por quatro concentraÃÃes de Si (0,0; 1,0; 1,5 e 2,0 mM) e quatro concentraÃÃes de NaCl (0, 50, 100 e 150 mM). A salinidade reduziu a altura e a matÃria seca das plantas de girassol, mas a presenÃa de Si no meio de crescimento reverteu tal efeito, resultando em plantas com maior altura e maior acÃmulo de matÃria seca, em comparaÃÃo Ãquelas nÃo tratadas com esse nutriente, mesmo quando sob estresse salino. AlÃm disso, o tratamento com Si induziu menor vazamento de eletrÃlitos nos tecidos foliares e radiculares e maior conteÃdo relativo de Ãgua nas folhas das plantas sob estresse salino, o que pode ter sido causado pelo acÃmulo de cristais de sÃlica nesses ÃrgÃos do vegetal. O Si crescente no meio de cultivo tambÃm induziu acÃmulo de proteÃnas solÃveis, prolina e N-aminossolÃveis nos tecidos foliares e radiculares, e essa resposta relacionou-se ao maior conteÃdo de nitrato e à maior atividade da redutase do nitrato, tanto nas folhas, quanto nas raÃzes das plantas tratadas com esse nutriente. Os danos oxidativos nas folhas e nas raÃzes de plantas de girassol foram parcialmente atenuados pelo tratamento com Si. De modo geral, a atividade das enzimas dismutase do superÃxido, peroxidase do ascorbato e catalase foi aumentada nas plantas mantidas sob condiÃÃes salinas e tratadas com Si. Assim, conclui-se que a aplicaÃÃo de Si no meio de crescimento atenuou os efeitos da salinidade nas plantas de girassol, especialmente nas maiores concentraÃÃes de Si empregadas (2 mM), levando-as a se aclimatarem adequadamente a esse estresse, por meio de melhorias no estado hÃdrico da planta, do acÃmulo de solutos orgÃnicos e de um sistema enzimÃtico antioxidativo mais eficiente.
24
Bell, Hester Louise. "Response of Sporobolus virginicus (L.) Kunthto salinity". Thesis, The University of Arizona, 2000. http://hdl.handle.net/10150/291593.
Testo completoAbstract (sommario):
Optimal growth of euhalophytes requires moderate concentrations of salt and, in dicots, is associated with succulence of leaves and stems and accumulation of Na⁺ in plant tissues. Relative growth rate, water and cation content were studied in Sporobolus virginicus, a C₄ Chlorodoid grass, grown under different concentrations of NaCl. Optimal growth occurred at 100-150 mmol/L NaCl. and was not dependent on nitrogen levels or accompanied by accumulation of Na⁺ in leaves. Na:K ratios were lower in leaves and rhizomes than in roots indicating the possibility of discrimination in Na⁺ and K⁺ transport from roots to leaves. Water content of leaves and shoots was significantly greater in plants grown at optimal levels of salinity than in plants grown at sub or supra optimal salinity. Na⁺ and K⁺ concentrations in leaves contribute approximately 60% of osmolality. These results support the characterization of S. virginicus as a euhalophyte.
25
Stougard, Pegeen O'Neil. "The role of salinity in equatorial mixed layers". Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1998. http://handle.dtic.mil/100.2/ADA350461.
Testo completoAbstract (sommario):
Thesis (M.S. in Meteorology and Physical Oceanography) Naval Postgraduate School, June 1998."June 1998." Thesis advisor(s): Roland W. Garwood, Arlene A. Guest. Includes bibliographical references (p. 53). Also available online.
26
Dale, Ryan. "Salinity, temperature, and macroinfaunal communities in groundwater seeps". Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file 9.34 Mb., p, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:1435921.
Testo completo
27
Gonzalez, Angel Ana Maria. "Porites astreoides Larval Response to Acute Salinity Stress". NSUWorks, 2013. http://nsuworks.nova.edu/occ_stuetd/178.
Testo completoAbstract (sommario):
Coral reef biodiversity is threatened by rapidly changing anthropogenic activities and natural perturbations, leading to massive ecological and economic consequences ranging from the loss of fisheries to coastal erosion. It is necessary to understand corals responses to environmental changes in order to determine management programs on appropriate spatial and temporal scales to address these issues. Coral larvae are the product of sexual reproduction, have the potential to recruit to new areas, and are fundamental in maintaining genetic diversity. These larvae are subjected to variations in local environmental conditions until they settle, inducing specific larval molecular response patterns. One factor that influences coral health is salinity. Low salinities can alter cell homeostasis creating stress in cells. In the natural environment larvae may be exposed to low salinities due to heavy rainfall or run-off. This study investigated larvae responses to low salinity and characterized gene expression in the reef-building coral Porites astreoides using a coral stress-focused microarray. Nine batches of 250+ larvae from three different colonies were collected and immediately exposed in an acute hyposalinity experiment. Samples from two treatments of 25 and 30 ppt, and a control at 35 ppt were used in this study. After experimental exposure these samples were stored in RNAlater® and molecular analysis was performed. The RNA from the samples was extracted, purified and hybridized to a coral stress-focused microarray. Statistical analysis indicates 72 genes were differentially expressed across treatments (p<0.003, analysis of variance). The hierarchical cluster analysis groups together the larvae exposed to salinities of 30 and 35 ppt indicating both treatments induced similar patterns of gene expression. Larvae responses to 30 ppt are minimal, suggesting larvae can tolerate acute exposures to 30 ppt salinity levels. In contrast, the lower salinity (25 ppt) induced a strong response in both the coral and zooxanthellae. The coral larvae up-regulated stress response genes and down-regulated genes associated with normal cell functioning. Additionally, the zooxanthellae down-regulated genes associated with photosynthesis. These results suggest larvae may be vulnerable to bleaching, which may affect the ability of larvae to successfully undergo metamorphosis and survive at low salinities. However, this has yet to be confirmed with complementary techniques. Long-term studies are recommended to examine the effects of hyposalinity on larvae at different time scales and life history stages.
28
Al-Harbi, Abdulaziz R. A. K. "Salinity and the growth of cucumber in hydroponics". Thesis, Imperial College London, 1991. http://hdl.handle.net/10044/1/46641.
Testo completo
29
Tonin, Hemerson E., e hemer tonin@flinders edu au. "Atmospheric freshwater sources for eastern Pacific surface salinity". Flinders University. Chemistry, Physics and Earth Sciences, 2006. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20061031.080144.
Testo completoAbstract (sommario):
The remarkable salinity difference between the upper Pacific and Atlantic Oceans is often explained through net export of water vapour across Central America. To investigate this mechanism a study of salinity signals in the Equatorial Pacific Ocean current system was made looking at responses to fresh water input from two sources (local versus remote - Atlantic Ocean) as well as a combination of the two. Statistical analyses (Empirical Orthogonal Functions, Single Value Decomposition and Wavelet analysis) were used to split the main sources of the atmospheric freshwater input into local and remote contributions and to quantify both contributions. The remote source was assumed to have been transported over Central America from the Atlantic Ocean as an atmospheric freshwater flux, whereas the local source originated in the Pacific Ocean itself. The analysis suggests that 74% of the total variance in precipitation over the tropical eastern Pacific is due to water vapour transport from the Atlantic. It also demonstrates strong influence of ENSO events, with maximum correlation at a two months time lag. During La Ni�a periods the precipitation variance is more closely related to water vapour transport across Central America (the remote source), while during El Ni�o periods it is more closely related to the water vapour transport by Southerly winds along the west coast of South America (the local source). The current and temperature fields provided by the Modular Ocean Model (version 2) were used to study the changes in the salinity field when freshwater was added to or removed from the model. ECMWF ERA-40 data taken from the ECMWF data server was used to determine the atmospheric flux of freshwater at the ocean surface, in the form of evaporation minus precipitation (E-P). The Mixed Layer Depth (MLD) computed from temperature and salinity fields determines to what depth the salinity's dilution/concentration takes place for every grid point. Each MLD was calculated from the results of the previous time step, and the water column was considered well mixed from the surface to this depth. The statistical relationships were used to reconstruct the precipitation over the tropical eastern Pacific. A numerical ocean model, which uses currents and temperature from a global ocean model and is forced by precipitation, was used to study the ocean's response to either the remote or the local source acting in isolation. Through time lag correlation analysis of the sea surface salinity anomalies produced by the variation in the reconstructed precipitation fields, it is found that the anomaly signals of salinity propagate westward along the Equator at a rate of approximately 0.25 m.s-1 (6.1 degrees per month).
30
Bhat, Shreyas. "Salinity (conductivity) sensor based on parallel plate capacitors". [Tampa, Fla] : University of South Florida, 2005. http://purl.fcla.edu/usf/dc/et/SFE0001381.
Testo completo
31
Gilstrap, Matthew Coleman. "Renewable electricity from salinity gradients using reverse electrodialysis". Thesis, Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/49031.
Testo completoAbstract (sommario):
Renewable power generation from the controlled mixing of sea and fresh water is relatively unexplored when compared to the development for solar, wind, and other sustainable power alternatives. When global river discharge was taken into account, an estimated 2.6 TW of obtainable energy exists in untapped salinity gradients. Reverse electrodialysis is one proposed power-generating mechanism for harnessing energy from brackish environments and relies on the transport of aqueous salt ions through an apparatus of ion-exchange membranes. In this thesis, operational parameters, including flow direction, salinity composition, and membrane selectivity, are investigated. For optimal performance, I have employed counter-current flow mode with monovalent ion selective membranes and pure 0.5 M NaCl saline solution. The results show that a maximum open circuit voltage (OCV) level of 2.01 V is obtained with an active membrane area of 0.0756 m². The presence of multivalent ions in the feed solutions hinders OCV levels, but the effects are reduced with monovalent-selective membranes. Preliminary results are insightful; in order to increase the commercially viability of this technology, future work is needed to enhance the performance properties of the ion exchange membranes.
32
Kwon, Taek-Ryoun. "Physiological studies of salinity tolerance in Brassica species". Thesis, Coventry University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361653.
Testo completo
33
Khan, Javed Ahmad. "Salinity effects on 4D recombinant tetraploid wheat genotypes". Thesis, Bangor University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321525.
Testo completo
34
Buya, J. K. "The genetics of salinity tolerance in Tilapia species". Thesis, Swansea University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.636193.
Testo completoAbstract (sommario):
Path coefficients were applied to estimate the amount of variation each physiological factor determines in the serum water content (SEWCON) or time-to-succumb (TS). Each estimate was used to reconstitute its own mean. In all cases, the re-constructed variables exhibited a higher value of VG/VP than in the original. This infers the expression of genetic variability masked by the composite action of many gene differences on the trait (Mather and Harrison 1949). VG/VP was related to neither the correlation or regression between groups. Correlation estimates differed from their intra-class correlations (rI). ANOVA values of VG/VP were similar to those of rI, which estimates the amount of genetic variability in the trait (Falconer 1981). VG/VP estimates from repeatability are not about how "repeatable" measures are (Falconer 1981), but rather the degree to which individuals differ from each other, the individuality (I). Both being standardized values (Bentsen 1994), the individuality readily translates into the heredity (h), the degree to which an individual's phenotype is determined by additive genetic factors. This idea was developed by Wright (1911) to define the heritability (h2); where hPPx ½hOP = ½h2 and hPP, the covariance between additive genetic and phenotypic values (COV (Ai, Pj)) which is also the covariance between parents and their respective family genotypic values (CO (giP, gjF)) (Mather and Harrison 1949). This is the additive degree of divergence (d), between parents (Bentsen 1994). When this quantity is estimated from half-siblings it has a magnitude of ¼h. The offspring-parent path (hOP), is the correlation of parent additive and offspring phenotypic values, (COV(AiP, PjO)). Its value is ½h. A domestication selection programme for tilapia species is proposed, where several lines of known genetic differences are generated to aid improvement programs through reciprocal recurrent selection (RRS).
35
Stringer, Christina Elaine. "Hydrologic Controls on Salinity in Mangroves and Lagoons". Scholar Commons, 2010. http://scholarcommons.usf.edu/etd/3583.
Testo completoAbstract (sommario):
This dissertation explores the hydrologic controls on salinity within mangroves and lagoons at sites in Florida and Mexico. The main objective of this research is to better understand hydrologic controls on mangrove ecosystem structure and develop ideas that will be useful to land managers attempting to regulate and conserve these critical habitats. This study was conducted at sites in Ft. Pierce, FL and Costalegre on the central Pacific coast of Mexico.
We examined controls on water levels and salinity in a mangrove on a carbonate barrier island along the Indian River Lagoon, east-central Florida. Spectral analysis of water levels showed that mangrove groundwater levels are not tidally influenced. Salinities vary spatially, with values of ~10 in upland environments to ~75 psu in irregularly-flushed mangroves. Water chemistry indicates that water salinities are largely controlled by enrichment due to evapotranspiration. An electrical resistivity survey showed that the freshwater lens is restricted to uplands and that hypersaline waters extend deeply below the mangrove. These results indicate that evapotranspiration lowers water levels in the mangrove, which causes Indian River Lagoon water to flow into the mangrove where it evapoconcentrates and descends, forming a thick layer of high-salinity water below the mangrove.
Spatial variability of terrain conductivity in the Ft. Pierce mangrove varied under two hydrologic management regimes, breached rotational impoundment management and rotational impoundment management. The difference in coefficient of variation (CV) between the breached RIM and RIM data was calculated to examine spatial variability in both the shallow and deep layers. A null-hypothesis model was employed to examine the statistical significance of the CV results. The average water levels were -0.06 m amsl and 0.49 m amsl during the breached-RIM and RIM regimes, respectively. The average shallow (EM31) layer terrain conductivity shifted slightly from 1868 mS m -1 to 1825 mS m-1 after the alteration in management regime, yet the standard deviation of these averages decrease from 656 mS m-1 to 216 mS m-1. The average deep (EM34) layer terrain conductivities were 328 mS m-1 and 255 mS m-1 during the breached-RIM and RIM regimes, respectively. The temporal CVs were 0.23 and -0.04 for the shallow and deep layers, respectively. The null-hypothesis model for the shallow layer illustrates that the difference in spatial structure is statistically significant. The deep layer CV was not statistically significant. These results indicate that the transition from breached RIM to RIM resulted in changes to both the physical and chemical hydrologic character of the impoundment, especially in the shallow layer.
The second study sites were three mangrove communities along the central Pacific Mexican coast. Salinities varied by water type, with values of ~9 in La Manzanilla, ~17 in La Vena, ~33 in Barra de Navidad, ~0.4 in the fresh waters, and ~34 in the seawater. Sodium and Chloride concentrations and isotopic signatures, as well as salinity, were used as tracers in mass-balance mixing models to quantify estimates of relative fresh-water and seawater contributions to each site. La Manzanilla, a basin mangrove, had mean fresh-water contribution estimates of 63-84%. La Vena, a riverine mangrove, had fresh-water estimates of 39-51%. Barra de Navidad, a fringe mangrove, had low fresh-water contributions of 0-5%. These results illustrates that the role groundwater plays in mangrove hydrodynamics is dependent on the site hydrogeomorphology.
36
Razzouk, S. "Effects of temperature and salinity on cotton quality". Thesis, University of Nottingham, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234699.
Testo completo
37
Alhdad, Gazala. "Responses of Suaeda maritima to flooding and salinity". Thesis, University of Sussex, 2013. http://sro.sussex.ac.uk/id/eprint/43812/.
Testo completoAbstract (sommario):
Suaeda maritima is an annual halophyte commonly found in salt-marshes. Its salt tolerance has been well studied, though there is little published on the effect of simultaneous waterlogging. The effects of saline waterlogging on growth, antioxidants (glutathione and total polyphenolic compounds, antioxidant activity) and oxidative damage were investigated with simulated tides in a controlled glasshouse and on plants collected from the field. Flooded shoots possessed higher levels of antioxidants than those from plants growing in well-drained situations, in the glasshouse and the field. The effects of hypoxia, (simulated in nutrient solution by flushing with nitrogen in a solution containing a low concentration of agar, which limits convection within the solution and so the transport of oxygen from the air) were determined on growth and trace metal concentrations, in plants grown in different concentrations of artificial seawater (100 and 350 mM Na+ at low pH, > pH 5.5), in sand/mud irrigated with halfstrength fresh seawater (at high pH, ca 7-8) and in different concentrations of manganese and iron in solution culture. High salt concentration reduced accumulation of trace metals in plants. Optimal growth occurred in 14 μM Fe and 1 mM Mn. Accumulation of trace metals was reduced at high pH, with more accumulating in the roots than the shoots. Hypoxia increased soluble sugars in shoots and roots, and this was affected by the salt concentration. Hypoxia also caused adventitious root development in hydroponic experiments, while in sand, adventitious root development was greater in drained than flooded conditions. Hypoxia significantly reduced shoot sodium concentration, sodium flux and bypass flow, at low and high salt concentrations. In high salt conditions, S. maritima reduced its transpiration rate and improved its water use efficiency. It was also shown that the roots contained high lactate concentrations under aerated and hypoxic conditions. S. maritima demonstrated many adaptations for tolerating extreme hypoxia.
38
Stuebe, David Allen. "Temperature and salinity variability in thermohaline staircase layers". Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/39194.
Testo completoAbstract (sommario):
Thesis (S.M.)--Joint Program in Physical Oceanography (Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences; and the Woods Hole Oceanographic Institution), 2005.Includes bibliographical references (p. 65-67).
A moored profiler record from the western tropical North Atlantic provides the first continuous time series of temperature, salinity and velocity profiles in a thermohaline staircase. Variations in the intensity of layering and the evolution of layer properties are well documented during the 4.3 month record. Such staircases are the result of strong salt fingering at the interfaces between the mixed layers, and these data provide unique insights into the dynamics of salt fingers. In particular, a striking linear correlation between the temperature and salinity of the layers may be interpreted as resulting from vertical salt finger flux divergences. Data from this record allow new interpretations of previous work on this topic by McDougall (1991).
by David Allen Stuebe.
S.M.
39
Møller, Inge Skrumsager. "Na⁺ exclusion and salinity tolerance in Arabidopsis thaliana". Thesis, University of Cambridge, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.612521.
Testo completo
40
Amini, Sina. "Hydrodynamics and Salinity of Pontchartrain Estuary During Hurricanes". ScholarWorks@UNO, 2014. http://scholarworks.uno.edu/td/1845.
Testo completoAbstract (sommario):
A hurricane is a combination of sustained winds, low atmospheric pressures and precipitation. Over the past decades, Louisiana has experienced several devastating hurricanes.
The east bank of the City of New Orleans is bounded by Lake Pontchartrain to the North and the Mississippi River to the South. Lake Pontchartrain is a brackish system connected to the Gulf of Mexico through Lake Borgne to the East. As a Hurricane enters the Estuary from the Gulf of Mexico, it imposes a sustained surge of a few meters which may lead to flooding in areas which are not protected by levees. These flood water may be saline.
Saltwater flooding is an environmental issue in flooded marshlands since saltwater can be fatal to some plants. The response of salinity and storm surge to hurricane duration which represents the forward speed of the storm is numerically modeled.
41
Kareem, Rikan Mohammed Ali. "Nano geochemistry of low salinity enhanced oil recovery". Thesis, Durham University, 2017. http://etheses.dur.ac.uk/12041/.
Testo completoAbstract (sommario):
In this thesis a wide range of analytical techniques were used to characterise several petrophysical properties of Berea sandstone, including the mineral distribution at the pore surface and its pore structure, both playing a crucial role in determining its response to low salinity enhanced oil recovery (EOR) investigations. In addition, the role of different cations in affecting the wettability state of pure quartz and Berea sandstone was experimentally investigated in order to gain an insight on the behaviour of sandstone reservoirs during low salinity waterflooding EOR. Results from the multi-technique, multi-scale characterisation of Berea indicate that the mineralogy exposed to the pore spaces is highly heterogeneous across different length scales, going down to the often-neglected nanoscale were significant amounts of phases identified as grain coatings. In addition, analysis of the porosity and pore-connectivity also requires a multi-length approach for its full characterisation to be realised. Both aspects are crucial to understand the role of mineral surface chemistry in determining oil/water and oil/minerals interactions in both experiments and field conditions. Investigations on wettability alteration using environmental scanning electron microscopy (ESEM) and contact angle measurements on ideal quartz surfaces showed that reduced salinity leads to a more water-wet state. These measurements were complemented with atomic force microscopy adhesion measurements on quartz surfaces, the results giving further insight into the role of nano-scale roughness on quartz surfaces in wettability alteration by increasing the amount of oil retained on the surface. Finally, similar wettability alteration experiments were performed on Berea sections. The effect of brine was consistent, reproducible and reversible and again showed a low salinity effect, i.e. a change to more water-wet conditions with lower salinity. The results also demonstrate that quartz surfaces always contributes at least in part to the low salinity effect, decreasing oil wettability when salinity is low. In addition, we demonstrate that the ESEM can be an essential tool in studying the wettability alteration of rocks and minerals.
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Schrader, Stephanie EllaJean, e Stephanie EllaJean Schrader. "Salinity Tolerance of Lettuce Cultivars in Controlled Environment". Thesis, The University of Arizona, 2017. http://hdl.handle.net/10150/624098.
Testo completoAbstract (sommario):
The specific objectives of this study were to determine the effects of increasing salinity on growth, crop quality, and physiological parameters of different lettuce (Lactuca sativa L.) cultivars grown either in a hydroponic system or in soil and subjected to irrigation water of varying salinity levels. Two trials were conducted in winter 2016 and summer 2016 in a greenhouse using a hydroponic system for the cultivation of three lettuce cultivars. 'Romaine del Sol', Leaf Lettuce 'Bergams Green' and 'Green Leaf Lettuce' were exposed to irrigation water with increasing salinity (2.1, 3.6, 5.1, and 6.6 dS/m) by supplementing the nutrient solution (2.1 dS/m) with a combination of 2:1 NaCl and CaCl2. Lettuce head height, diameter, leaf number, shoot and root dry weight were not impacted by increasing salinity. Similarly, osmotic potential, transpiration and leaf temperature were not affected. However, head fresh weight and water content were reduced at the higher salinity levels compared to the control in the second trial. A third greenhouse trial was conducted in winter 2017 with 'Romaine del Sol' and 'Green Leaf Lettuce' cultivars grown in a hydroponics system or in containers with soil to determine tolerance to increasing salinity in different substrates. Head height, diameter, and shoot dry mass decreased at the two highest salinity levels at the final harvest. When plants were smaller, salinity had no effect on these variables. Fresh weight, water content, and leaf number decreased with increasing salinity at final harvest for both cultivars however, osmotic potential of both cultivars was not affected by salinity or substrate throughout the study. An informal taste test found that the leaves from the two highest levels of salinity from both cultivars were inedible because of a salty and bitter taste. Mineral concentration of sodium and chloride in ‘Romaine’ and 'Green Leaf Lettuce' increased as salinity levels increased, and plants of both cultivars grown in soil had greater concentrations of both elements when compared to hydroponics. 'Romaine' and 'Green Leaf Lettuce' are more tolerant to salinity than previously reported in other lettuce cultivars, and the physiological variables measured showed little changes in response to increasing salinity. Although lettuce grown at 5.1 dS/m and 6.6 dS/m was marginally acceptable by size standards, the lack of head formation in ‘Romaine del Sol’, and the unfavorable taste of both cultivars would render them unmarketable.
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Hartzell, Jeanne L. "The fate of phosphorus along estuarine salinity gradients". Fairfax, VA : George Mason University, 2009. http://hdl.handle.net/1920/4505.
Testo completoAbstract (sommario):
Thesis (Ph.D.)--George Mason University, 2009.Vita: p. 152. Thesis director: Thomas E. Jordan. Thesis director: Donald P. Kelso. Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Environmental Science and Public Policy. Title from PDF t.p. (viewed June 10, 2009). Includes bibliographical references (p. 140-151). Also issued in print.
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Khatun, Saleha. "Effect of salinity on seed set in rice". Thesis, University of Sussex, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333445.
Testo completo
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Reid, Elizabeth. "Salinity shocking and fouling amelioration in membrane bioreactors". Thesis, Cranfield University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.653080.
Testo completo
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Poscher, Elisabeth. "Salinity Effects on Guayule Leaf Anatomy and Physiology". Diss., The University of Arizona, 2005. http://hdl.handle.net/10150/194362.
Testo completoAbstract (sommario):
Salinity usually reduces plant growth in terms of height and biomass, but can increase secondary metabolite production. This frequently reported observation in guayule (Parthenium argentatum Gray, Asteraceae) was investigated for possible mechanisms.Osmotic and specific ion effects of four chloride salts (CaCl2, MgCl2, KCl, and NaCl) on leaf anatomical and plant physiological parameters were studied. One-year-old plants of guayule line AZ 2 were grown under two salt concentrations (750 ppm and 1500 ppm) for each salt type (plus a control) in sand culture (semi-hydroponic) for eight weeks under controlled greenhouse conditions in Tucson, Arizona.Growth in height decreased with increasing salt concentration. Shoot dry weight, rubber, and resin contents, however, showed no significant differences between treatments, indicating no effect from either salt concentration or salt type. There was a trend for increasing rubber content with increasing salt concentration, although not statistically significant. At the same time, net CO2 gas exchange rates decreased significantly with increasing salinity.With increasing salt concentration, guayule showed osmotic effects in terms of height, indicating a lower hydraulic conductivity. Although plants of higher salt concentrations utilized significantly less water, they had the same shoot dry weights, rubber, and resin contents. Salt-stressed plants therefore achieved higher water use efficiencies. The diurnal net CO2 gas exchange rates were significantly reduced with increasing salinity; the nocturnal net CO2 gas exchange rates showed no significant difference between the treatments.Anatomically, it was found that the stomata were raised or elevated above the epidermis, and supported by upwardly curving cells. When guayule was grown under salt treatments, the trichomes were found to include deposits of material. Trichomes might act as a detoxification repository for excess ions. Although the physiological significance of raised stomata is unknown, it is hypothesized that the unique combination of raised stomata, indumentum, and multiple layers of palisade parenchyma allows for an overall high photosynthetic capacity and performance. During stress conditions such as salinity or drought, guayule might activate an internal CO2 concentrating mechanism, i.e., bicarbonate/CO2 pump, internal CO2 recycling, or PEP carboxylation activity.
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Wang, Lijun. "Physiological response of Kentucky bluegrass under salinity stress". DigitalCommons@USU, 2013. https://digitalcommons.usu.edu/etd/1492.
Testo completoAbstract (sommario):
Salinity is a major abiotic stress in plant agriculture which reduces seed germination, vegetative growth, and flowering, and limits crop productivity world-wide. Salinity causes water deficit, ion toxicity, and nutrient deficiency in plants, which can result in cellular damage, growth reduction, and even death. Kentucky bluegrass (Poa pratensis L.) is the most widely used cool-season species in cool-arid climates; however it has relatively poor salt-tolerance. Thus the development of Kentucky bluegrass genotypes with increased salt tolerance is of interest to turf breeders. One impediment to selection towards this goal is finding an efficient and accurate method to evaluate the salt tolerance. The objective of this study was to examine physiological responses to salt stress and to evaluate the genetic diversity among the accessions used in the research. Salt-tolerant accessions PI371768 (768) and PI440603 (603) and salt-sensitive varieties Midnight and Baron were exposed to four levels of salinity imposed by irrigating with salt solutions of 0 dS m-1 (control), 6 dS m-1, 12 dS m-1, and 18 dS m-1 or 24 dS m-1. Soil salinity was measured using Acclima Digital TDT sensors and grass response to the stress was measured using turf quality ratings, stomatal conductance, leaf water potential and electrolyte leakage. In general, turfgrass quality, stomatal conductance, and leaf water potential decreased while electrolyte leakage increased under salinity stress. Midnight and Baron exhibited greater changes in these measurements, indicating more sensitivity compared to 768 and 603. The 6 dS m-1 treatment had little effect on the salt-tolerant accessions. Salt tolerance of 603 and 768 was confirmed and likewise, salt sensitivity of Baron and Midnight was confirmed. The genetic similarity of all cultivars used in this study was very high.
All of the evaluation measurements were highly correlated, with water potential and electrolyte leakage being the most reliable and accurate methods due to the low standard deviations. Due to more repeatable methods and less user error, electrolyte leakage and turfgrass quality are recommended methods for screening salt tolerance of turfgrasses.
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Hawks, Austin McCoy. "Salinity Inventory and Tolerance Screening in Utah Agriculture". DigitalCommons@USU, 2009. https://digitalcommons.usu.edu/etd/546.
Testo completoAbstract (sommario):
Soil salinity, a yield-limiting condition, has plagued crop production for centuries by reducing crop productivity. Research has introduced methods for successfully managing soil salinity. This research discusses the adaptation of established management methods to create new soil salinity management techniques. One adapted technique is an automated crop screening apparatus. A new design was created and successfully used in rapidly screening two strawberry cultivars to determine their tolerance to salinity. Screening crops and determining their tolerance to yield-limiting conditions are essential in managing soil salinity. Another salinity management tool used in this research was electromagnetic induction (EMI). EMI was used to complete a basin-scale inventory over an 18,000 ha study area in Cache County, Utah. The data obtained during the inventory were used to create EMI calibration models and a basin-scale map showing the spatial distribution of apparent soil electrical conductivity (ECa). These new methods for crop tolerance screenings and basin-scale salinity inventories will assist in successfully managing soil salinity and decrease its effect on the global food supply.
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LANZONI, ALESSANDRA. "The Messinian Salinity Crisis in the Adriatic Sea". Doctoral thesis, Università degli Studi di Trieste, 2022. http://hdl.handle.net/11368/3030771.
Testo completoAbstract (sommario):
The framework of this thesis investigated the effect of the Messinian Salinity Crisis (MSC; 5.97-5.33 Ma) in the Adriatic Sea, one of the most controversial geological events that occurred in the Mediterranean Basin. The main objectives included the analysis of surfaces and units of the MSC to evaluate the thickness of the MSC deposits and their relationships with the effect of different phenomena such as erosion, non-deposition, and Plio-Quaternary deformation, all related to the geological evolution of the Adria plate and its role as Apennine foreland. Moreover, the Adriatic Sea represents a not fully understood problem in the framework of the MSC and its connection with the other Mediterranean basins.
The Adriatic Sea is one of several restricted basins located in the Mediterranean Basin. It represents the foreland of three orogenic belts: the Southern Alps to the North, active since the Cretaceous time; the Dinarides to the East, active during the Eocene; and the Apennines to the West, active since the Paleogene.
For the aim of this thesis, more than 10000 km long 2D multichannel seismic profiles were analyzed, calibrated by 218 boreholes, covering almost the whole Adriatic Sea in the Italian and partially Croatian offshore. The interpretation of the seismic lines in the Adriatic Sea has been carried out thanks to the IHS Kingdom Suite software. A precise and careful seismo-stratigraphy analysis was performed to recognize the different facies of the sedimentary sequence, focusing on the MSC expression.
Analysis of the MSC surfaces and unit allowed to produce of the map of the base of the Plio-Quaternary sequence and the thickness of the evaporites. In particular, the Adriatic Sea was divided into three main geographical areas based on the occurrence of the MSC. Our results showed that the Northern Adriatic Sea during the MSC experienced subaerial exposure in front of the Trieste and Venice Gulfs. At the same time, evaporite deposition occurred in the modern Rimini foredeep. The Central Adriatic Sea shows the combined effect of deposition and erosion, with several channel incisions in this area, are related to paleo-drainage systems. The Southern Adriatic Sea shows an intense erosion on the carbonate platform, while MSC evaporites are present and eroded along the margins of the South Adriatic Basin.
Following the MSC, the east migration of the Apennine Chain was covered with the external thrust and obliterated part of the MSC. From the Late Pliocene, the Adriatic Sea underwent different evolutionary steps. Boreholes calibration highlight the presence of locally very thin Pliocene succession in the entire Adriatic Sea. The main effect of the Apennines' eastward migration occurred during the Lower Pliocene, as testified by the regional tilting of the MSC reflectors, onlapped by Plio-Quaternary (PQ) parallel reflectors. The Southern Adriatic Sea was affected, starting from the Pliocene, by the Albanides orogenesis, as testified by the eastward foreland tilting, where PQ sediments onlap the MSC unconformity.
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Garthwaite, Alaina Jane. "Physiological traits associated with tolerance to salinity and waterlogging in the genus 'Hordeum' /". University of Western Australia, 2005. http://theses.library.uwa.edu.au/adt-WU2005.0133.
Testo completoAbstract (sommario):
Wild Hordeum species, from the four genome groups of X, H, I and Y, were assessed for physiological traits associated with tolerance to salinity and waterlogging. When grown in saline conditions, a number of wild Hordeum species had exceptional ‘exclusion’ of Na+ and Cl- from the young leaves, and also maintained tissue K+ concentrations, compared with Hordum vulgare ssp. vulgare (cv. ‘Golf’). For example, at 150 mol m-3 NaCl, the K+:Na+ in youngest, fully expanded leaf blades of wild Hordeum species averaged 5.2, compared with 0.8 in H. vulgare. H. marinum was more salt tolerant than H. vulgare, with a relative growth rate 30% higher than H. vulgare at 150 mol m-3 NaCl. At 300 mol m-3 NaCl, glycinebetaine plus proline contributed to 15% of πsap in expanding leaf blades of H. marinum, compared with 8% in H. vulgare. When grown in stagnant conditions, 16 accessions (approximately half of those evaluated) formed a barrier to radial O2 loss (ROL) in basal zones of adventitious roots. In the Triticeae, this trait had previously only been described in one species, H. marinum. The barrier to ROL occurred only in accessions from wetland or intermediate habitats, and was also related to genome type, being present in accessions with the X or the H genome (Hordeum vulgare has the I genome). In stagnant conditions, aerenchyma formed was, on average; 22% in accessions with the X genome; 19% in those with the H genome; and 15 and 16% in those with the I or the Y genomes, respectively. The combination of a barrier to ROL and aerenchyma enhances longitudinal O2 movement in adventitious roots, permitting roots to penetrate deeper into anaerobic substrates. In H. marinum, induction of the barrier to ROL was associated with a 97% reduction in apparent O2 diffusivity across the external layers of the basal zones of roots, compared with near the root tip. The barrier results from physical resistance to radial O2 movement, although when roots were cooled to suppress respiration some additional leakage of O2 was detected, indicating respiration also contributes to the low rates of ROL from the basal regions of roots. Low radial O2 permeability in the roots of stagnantly-treated H. marinum was associated with secondary thickening, putatively lignin or suberin deposits, in the hypodermis. These changes in root structure, however, did not influence root hydraulic conductivity, assessed for individual adventitious roots and whole root systems. Thus, diversity amongst Hordeum species in expression of traits for tolerance to waterlogging (an inducible barrier to ROL and aerenchyma) and salinity (Na+ and Cl- ‘exclusion’) were documented in this study. Traits for root aeration did not compromise the capacity of roots to take up water, presumably being of importance for growth in soils with fluctuating water levels (i.e. wet/dry cycles). The high degree of salinity tolerance in several Hordeum species, and especially in H. marinum, is consistent with field observations that these species occur in salt affected areas