• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 770
  • 277
  • 172
  • 89
  • 38
  • 36
  • 30
  • 22
  • 22
  • 22
  • 22
  • 22
  • 22
  • 15
  • 14
  • Tagged with
  • 1933
  • 169
  • 156
  • 154
  • 147
  • 137
  • 126
  • 118
  • 117
  • 114
  • 98
  • 95
  • 92
  • 81
  • 76
  • 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.
281

Isolation and Characterization of a new thermotolerant pigment- producing microalga: Salt stress enhances pigment and oil biosynthesis in Coelastrella sp.F50

Hu, Che-Wei 22 August 2012 (has links)
A new species of reddish-orange pigment-producing microalga was isolated from a shallow pond in tropical Taiwan. Morphological and molecular evidence including meridional ribs on the cell wall, pigment production, and 18S rDNA sequence analysis suggest that this microalga is a species in the genus Coelastrella. Salt stress accelerated biosynthesis of the reddish-orange pigments, and large quantity of oil accumulated as the cells stressed under nutrient deficiency. This microalga could sustain 45 ¢XC for more than 8 hours indicated by the stability of its chlorophylls, which is a necessary trait for large scale outdoor cultivation using photobioreactors in tropical areas. The reddish-orange pigments could be separated into many fractions by HPLC, and signals from carotenoids were detected in a few fractions using NMR, suggesting these pigments may function as antioxidants among other roles.
282

Salt Control on Sedimentary Processes in Early Pleistocene: Ship Shoal South Addition Blocks 349-358, Gulf of Mexico.

Syarif, Munji 30 September 2004 (has links)
The interpretation of 3D seismic data from Ship Shoal South Addition Blocks 349-358, Gulf of Mexico shows a complex interaction between salt, faults, and sedimentary strata. Reconstruction of the geometry of early Pliestocene (about 3.65 Ma) through recent salt and associated sediments reveals the evolution of a supralobal basin in the study area. The basin depocenter shifted from the northeastern part to the center of the study area through time. A small, bulb-shaped, salt-stock structure occurs in the northwest, and a salt sheet structure is present in the southeastern part of the study area. Those structures are part of a pennant-shaped structure bounded by counter regional faults trending northeastward. Salt movements created instability and triggered extensive faulting of the overlying strata. Three-dimensional reconstruction suggests that salt blocked the sediment during the early Pleistocene. The sediment was diverted around the salt high on both east and west sides of the salt body to the southwest and southeast. Stratigraphic interpretation of the interval between 1.35 Ma and 1.95 Ma led to the identification of a highstand systems tract (HST), a transgressive systems tract(TST), and two lowstand systems tracts (LST). The strata are developed normally in the depocenter area, whereas the strata at the basin margin were deformed by salt movement and faulting. Each systems tract is uniquely associated with a certain seismic facies. Three seismic facies were identified associated with LST, TST, and HST. Additionally, seismic sections reveal channel geometries in the LST. Seismic attribute analysis elucidates facies distribution in the systems tracts. Because of its ability to move, to divert sediment, to create instability, and to block sediment transport pathways, salt exercises the main control on the sedimentary processes in the study area.
283

The heat and salt balances of the upper ocean beneath a spatially variable melting sea ice cover /

Hayes, Daniel Reiner, January 2003 (has links)
Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 112-118).
284

A study of salt tolerance in Arabidopsis thaliana and Hordeum vulgare

Attumi, Al-Arbe M. January 2007 (has links)
Thesis (Ph.D.) - University of Glasgow, 2007. / Ph.D. thesis submitted to the Division of Biochemistry and Molecular Biology, Biomedical and Life Sciences (IBLS), University of Glasgow, 2007. Includes bibliographical references. Print version also available.
285

Response of minibasin subsidence to variable deposition : experiments and theory

Kopriva, Bryant Timothy 20 July 2012 (has links)
Differential loading induced deformation of a mobile substrate (e.g., salt tectonics) is an important process for the development of accommodation space and stratigraphic architectures in intra-slope minibasins. Numerous studies of minibasin systems have focused on either the tectonic processes involved in salt body deformation or the stratigraphic interpretation of the overburden sediment deposits. This study, however, focuses on coevolution of depositional and tectonic processes and provides a new insight of the linked evolution into the stratigraphic patterns. Using a silicone polymer to simulate a viscous mobile substrate, a series of 2D experiments were conducted to explore the effects of variation in 1) sedimentation rate, 2) depositional style (intermittent sediment supply), and 3) the thickness of the deformable salt substrate on subsidence patterns and minibasin evolution. Experiments results have shown that larger initial thickness of salt substrate as well as lower sedimentation rate caused greater amounts of subsidence for a given amount of deposit. Furthermore, increase in subsidence rate was observed as sedimentation continued, while decrease in subsidence rate occurred once sedimentation ceased. Due to the linked depositional and tectonic processes, higher sediment supply resulted in relatively slower subsidence and more actively widening minibasins. Lower sediment supply was observed to have the reverse effect, resulting in higher relative subsidence and a narrow basin width. A numerical model that captures viscous flow under the deposit is also presented here. The model for minibasin formation showed the effects of interaction of the two processes (deposition and tectonics) on the development of minibasin strata in the experiments. Experimental and modeled findings have resulted in a new model of minibasin development that incorporates the effects of sedimentation rates on subsidence patterns into basin evolution. / text
286

Electrode separation effects in capacitive deionization desalination systems

Pierce, Kena Marie 29 November 2012 (has links)
A more energy efficient and sustainable method of desalinating water is needed due to increasing water shortages and contamination of current freshwater sources. Capacitive deionization (CDI), a new emerging technology, is a type of electric desalination that uses an applied voltage to pull the salt ions out of the salty solution and store the ions in porous carbon electrodes. CDI uses less applied energy than more commonly used methods of desalination like reverse osmosis and multi-flash distillation and has the added advantage of energy recovery. This report details experiments conducted to analyze the effect of different separation distances between the electrodes on salt ion adsorption for a high concentration solution under various flow rates and a 1 V voltage potential difference. The testing was performed in the Multiscale Thermal-Fluids Laboratory at The University of Texas at Austin using a uniquely fabricated CDI cell. Voltage, elapsed time, and electrical conductivity measurements were taken during the testing. Electrical conductivity was used to signify salinity of the solution. Two different separation distances were created by placing either one 2mm mesh between the electrodes or by using two 2 mm meshes between the electrodes. The results did not agree with the expectation that the one-mesh tests would adsorb twice the amount of salt ions as the two-mesh tests because of the differences in the electric field between the two types of tests. This is believed to be due to the high concentration tested. Future testing should include repeating these tests to verify the results and performing the tests for lower concentrations to see if they followed the expectation. / text
287

Albian/Maastrichtian tectono-stratigraphic evolution of Central Santos Basin, Offshore Brazil

Pequeno, Mônica Alves 04 February 2013 (has links)
The dissertation examines the interaction between basement tectonics, salt tectonics and sedimentation during the Late Cretaceous basement reactivation in the center of the Santos Basin. The study area is a seismic volume 60 x 30 km² in area, augmented by 2D regional seismic lines. The results of seismic interpretation and structural restorations revealed important inversions in the Late Cretaceous, including inversion of an NNE-oriented aborted rift segment known as Merluza Graben. The following tectono-stratigraphic evolution was inferred. During the Albian, basin subsidence and differential loading by the overburden caused salt to flow basinwards. In the Late Turonian, intraplate compression resulted in uplift of the onshore and proximal areas of the Santos Basin and in a newly recognized basement inversion in deep water. ENE and NNE oriented structures were reactivated. The uplift exposed the Turonian shelf and a new shelf began to prograde. The first shelves were narrow (~25 km wide) but enlarged to 60 km in the Santonian. Salt influenced the position of the shelf break and the progradation pattern of the shelf margin. Because of the continuous accommodation space provided by salt withdrawal underneath the sedimentary wedge, the shelf margin aggraded until underlying salt welded, after which the shelf prograded to a position around 50 km to the east of the present-day shelf break. Deformation peaked in the Late Santonian when the shelf was widest, the rate of progradation of the shelf margin was anomalously high, and transtension along the borders of the Merluza Graben allowed Late Santonian magma to intrude. Salt acted as a partial seal, causing a large part of the magma to spread beneath it. Some magma formed sills inside the evaporitic layer, intruding zones of dilation in the salt. Magma also followed the top of the evaporitic layer and intruded salt-related faults as dikes. These dikes supplied sills in the overburden and extrusive flows emerged on the Late Santonian seafloor from ENE-striking transtensional zones. Right-lateral reactivation of the Merluza Graben borders slightly compressed the graben, which favored sill injection in Coniacian/Santonian strata. Tectonic activity diminished towards the end of the Cretaceous. / text
288

Salt tectonics and sequence-stratigraphic history of minibasins near the Sigsbee Escarpment, Gulf of Mexico

Montoya, Patricia 28 August 2008 (has links)
Not available / text
289

Salt River Valley Soils

Forbes, Robert H. 03 1900 (has links)
This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.
290

RECURRENT SELECTION FOR GERMINATION SALT TOLERANCE IN ALFALFA (SALINITY, FORAGES, BREEDING)

Robinson, David Lowell, 1955- January 1986 (has links)
No description available.

Page generated in 0.4074 seconds