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Full-Text Articles in Life Sciences

Eco-Assessment Of Phytoplankton Composition In Relation To Environmental Conditions Of Saltwater And Freshwater Lakes In The Konya Closed Basin (Türkiye), Abuzer Çelekli, Ömer Lekesiz, Tolga Çetin May 2024

Eco-Assessment Of Phytoplankton Composition In Relation To Environmental Conditions Of Saltwater And Freshwater Lakes In The Konya Closed Basin (Türkiye), Abuzer Çelekli, Ömer Lekesiz, Tolga Çetin

Turkish Journal of Botany

Great importance is given to maintaining lentic ecosystems, threatened by human-induced consequences worldwide. The present study hypothesized to assess differences in species-environment relationships and ecological status of 15 lakes (saline water systems, high-altitude freshwater lakes, and other freshwater lakes) in the Konya Closed River Basin using phytoplankton indices throughout wet and dry periods. Results of canonical correspondence analysis separated saline and freshwater (high-altitude) habitats, which were characterized by different phytoplankton species. Total phosphorus (TP), electrical conductivity (EC), nickel-Ni, and altitude were the most influential environmental factors affecting phytoplankton dispersal in these ecosystems. Saline lakes were under pressure of high EC, …


Model Of Groundwater Level Control Using Horizontal Drainage, A. Arifjanov, M. Otaxonov, Z. Abdulkhaev Dec 2021

Model Of Groundwater Level Control Using Horizontal Drainage, A. Arifjanov, M. Otaxonov, Z. Abdulkhaev

Irrigation and Melioration

The article describes the main factors affecting the rise in the level of groundwater in the city of Fergana and ways to eliminate them. Currently, in order to reduce the negative impact of rising groundwater levels on the environment, crops, buildings and structures, as well as underground utilities, it is proposed to design horizontal drainage in urban areas and a mathematical model has been developed for changing the groundwater level. For this, long-term data from observation wells were analyzed and the hydraulic parameters of horizontal drainage were selected taking into account the hydrogeology of the area. Taking into account the …


Conductivity Measurements For Lunar Orbital Platform-Gateway (Lop-G) Materials, Crystal Tingle Apr 2021

Conductivity Measurements For Lunar Orbital Platform-Gateway (Lop-G) Materials, Crystal Tingle

Student Research Symposium

The focus of this research is to characterize materials that are being considered for use in the development of the Lunar Gateway Space Station (LOP-G). The LOP-G will experience ultra-high vacuum and bombardment by solar radiation, which subject the spacecraft to a phenomenon referred to as spacecraft charging. Spacecraft charging can be defined as extra charge accumulated in spacecraft materials from solar radiation, plasma environments, magnetic fields, and more. If a material accumulates too much charge, it may discharge arcs to surrounding components, which can cause electronic failure, structural damage, and ablation of thermal coatings. To avoid this, materials must …


Diatom Community Responses To Development And Climate Change In Lake George, An Oligotrophic Lake In The Adirondack Mountains, Adam T. Ruka Jan 2020

Diatom Community Responses To Development And Climate Change In Lake George, An Oligotrophic Lake In The Adirondack Mountains, Adam T. Ruka

Masters Theses

Lake George is a highly monitored, oligotrophic lake that experiences widespread tourism in the summer months. The southern basin is more developed than the northern basin, suggesting a north-south gradient of anthropogenic impairment. This study aimed to assess differences in nearshore diatom communities regarding gradients of water chemistry and watershed development throughout the lake. Using Redundancy analyses, water chemistry was found to explain more variation within diatom assemblages than watershed variables. Weighted averaging optima and tolerances specified taxa of concern, F. gracilis and A. formosa, that indicate increased phosphorus (μg/L) and conductivity (μS/cm), respectively. Two hypotheses related to the effect …


Lanthanide-Doped Ceria Nanoparticles As Backside Coaters To Improve Silicon Solar Cell Efficiency, Ali Hajjiah, Effat Samir, Nader Shehata, Mohamed Salah May 2018

Lanthanide-Doped Ceria Nanoparticles As Backside Coaters To Improve Silicon Solar Cell Efficiency, Ali Hajjiah, Effat Samir, Nader Shehata, Mohamed Salah

Biology Faculty Publications

This paper introduces lanthanide-doped ceria nanoparticles as silicon solar cell back-side coaters, showing their influence on the solar cell efficiency. Ceria nanoparticles can be synthesized to have formed oxygen vacancies (O-vacancies), which are associated with converting cerium ions from the Ce4+ state ions to the Ce3+ ones. These O-vacancies follow the rule of improving silicon solar cell conductivity through a hopping mechanism. Besides, under near-ultra violet (near-UV) excitation, the reduced trivalent cerium Ce3+ ions are directly responsible for down converting the un-absorbed UV wavelengths to a resultant green photo-luminescence emission at ~520 nm, which is absorbed through …


Diet Composition Explains Reductions In Stream Salamander Occupancy And Abundance Along A Conductivity Gradient, Jacob Matthew Hutton Jan 2018

Diet Composition Explains Reductions In Stream Salamander Occupancy And Abundance Along A Conductivity Gradient, Jacob Matthew Hutton

Theses and Dissertations--Forestry and Natural Resources

Changes in land use such as mountaintop removal mining with valley fills (MTR/VF) affect chemical, physical, and hydrological properties of headwater streams. Although numerous stream taxa have experienced significant declines from MTR/VF, stream salamanders appear to be particularly sensitive. Yet, the specific mechanism(s) responsible for the population declines has eluded researchers. We sampled salamander assemblages across a continuous specific conductivity (SC) gradient in southeastern Kentucky and estimated occupancy rates and abundance estimates along this gradient. We also examined the diet of larval and adult salamanders to determine if autochthony (A/T prey), total prey volume, and body condition is influenced by …


Dielectric Properties Of Isolated Adrenal Chromaffin Cells Determined By Microfluidic Impedance Spectroscopy, A. C. Sabuncu, M. Stacey, G. L. Graviso, N. Semenova, P. T. Vernier, N. Leblanc, I. Chatterjee, J. Zaklit Jan 2018

Dielectric Properties Of Isolated Adrenal Chromaffin Cells Determined By Microfluidic Impedance Spectroscopy, A. C. Sabuncu, M. Stacey, G. L. Graviso, N. Semenova, P. T. Vernier, N. Leblanc, I. Chatterjee, J. Zaklit

Bioelectrics Publications

Knowledge of the dielectric properties of biological cells plays an important role in numerical models aimed at understanding how high intensity ultrashort nanosecond electric pulses affect the plasma membrane and the membranes of intracellular organelles. To this end, using electrical impedance spectroscopy, the dielectric properties of isolated, neuroendocrine adrenal chromaffin cells were obtained. Measured impedance data of the cell suspension, acquired between 1 kHz and 20 MHz, were fit into a combination of constant phase element and Cole-Cole models from which the effect of electrode polarization was extracted. The dielectric spectrum of each cell suspension was fit into a Maxwell-Wagner …


Weatherbird Ii Sediment Cruise Sample Data 2015, Patrick Schwing Feb 2017

Weatherbird Ii Sediment Cruise Sample Data 2015, Patrick Schwing

C-IMAGE data

This dataset includes the locations and allotments of multicore sediment samples, water sample locations, and CTD data from cruises aboard the R/V Weatherbird II from 2015.


Biomechanical Characterization And Modeling Of Human Tmj Disc, Gregory Wright May 2015

Biomechanical Characterization And Modeling Of Human Tmj Disc, Gregory Wright

All Dissertations

Temporomandibular joint (TMJ) disorder affects over 10 million people in the US each year. The signs and symptoms of temporomandibular joint disorders (TMDs) include limited mouth opening, clicking and locking of the jaw, and significant pain in the craniofacial region. In patients who seek treatment for TMDs, over 70% have TMJ disc displacement related to disc degeneration. The TMJ disc is interposed between the mandible condyle and the glenoid fossa of the temporal bone. The disc reduces contact stresses within the joint and provides lubrication to the joint. It is generally believed that pathological mechanical loadings, such as sustained jaw …


Germination And Electrical Conductivity Tests On Artificially Aged Seed Lots Of 2 Wall-Rocket Species, Simona-Laura Lazar, Sara Mira, Doru Pamfil, Juan Bautista Martinez-Laborde Jan 2014

Germination And Electrical Conductivity Tests On Artificially Aged Seed Lots Of 2 Wall-Rocket Species, Simona-Laura Lazar, Sara Mira, Doru Pamfil, Juan Bautista Martinez-Laborde

Turkish Journal of Agriculture and Forestry

The aim of this study was to determine whether the loss of germinability and vigour in wall-rocket seed lots was related to electrolyte leakage. Ten seed lots of 2 wall-rocket species (9 of Diplotaxis tenuifolia and one of D. erucoides (Brassicaceae)) were stored at 45 °C and 70% relative humidity and electrolyte leakage was measured using the conductivity test. Small differences in longevity were found among species or seed lots, suggesting that a similar relative longevity might be expected within the genus Diplotaxis after artificial ageing, and that it will be above the average of that found in other species …


Electronic Interactions Within Composites Of Polyanilines Formed Under Acidic And Alkaline Conditions. Conductivity, Esr, Raman, Uv-Vis And Fluorescence Studies, L Dennany, P C. Innis, S T. Mcgovern, Gordon G. Wallace, Robert J. Forster Mar 2013

Electronic Interactions Within Composites Of Polyanilines Formed Under Acidic And Alkaline Conditions. Conductivity, Esr, Raman, Uv-Vis And Fluorescence Studies, L Dennany, P C. Innis, S T. Mcgovern, Gordon G. Wallace, Robert J. Forster

Gordon Wallace

The properties of two forms of polyaniline (PAni) synthesised under acidic and basic conditions have been investigated both individually and as combined complexes. The PAni polymerised within alkaline media was redox inactive and non-conducting while the PAni emeraldine salt (ES) was electroactive and conducting. Raman, electron spin resonance, UV-Vis and fluorescence spectroscopies were used to monitor the changes in electronic properties of these conducting polymer composites. Solution cast films of alkaline synthesised (A-PAni) with the PAni ES resulted in an increase in the high spin polaron population suggesting that it acts as a pseudodopant. The ability of the A-PAni to …


Effects Of Conductivity And Fish Grazing On Alkaline Phosphatase Activity Of Littoral Periphyton, Samuel A. Drerup Jan 2012

Effects Of Conductivity And Fish Grazing On Alkaline Phosphatase Activity Of Littoral Periphyton, Samuel A. Drerup

Browse all Theses and Dissertations

Littoral periphyton plays an important role in whole lake primary production and is a substantial contributor to whole lake energy budgets in moderately deep oligotrophic lakes. Under conditions of nutrient deficiency, members of the periphyton community supplement the available nutrient pool through the production of intracellular and extracellular enzymes. These enzymes are used to convert bio-unavailable forms of nitrogen and phosphorous to forms usable by the periphyton community. In this paper, I will investigate how conductivity and fish grazing affect periphyton production and phosphorus acquisition in both field and laboratory experiments.


Electronic Interactions Within Composites Of Polyanilines Formed Under Acidic And Alkaline Conditions. Conductivity, Esr, Raman, Uv-Vis And Fluorescence Studies, L Dennany, P C. Innis, S T. Mcgovern, Gordon G. Wallace, Robert J. Forster Jan 2011

Electronic Interactions Within Composites Of Polyanilines Formed Under Acidic And Alkaline Conditions. Conductivity, Esr, Raman, Uv-Vis And Fluorescence Studies, L Dennany, P C. Innis, S T. Mcgovern, Gordon G. Wallace, Robert J. Forster

Faculty of Science - Papers (Archive)

The properties of two forms of polyaniline (PAni) synthesised under acidic and basic conditions have been investigated both individually and as combined complexes. The PAni polymerised within alkaline media was redox inactive and non-conducting while the PAni emeraldine salt (ES) was electroactive and conducting. Raman, electron spin resonance, UV-Vis and fluorescence spectroscopies were used to monitor the changes in electronic properties of these conducting polymer composites. Solution cast films of alkaline synthesised (A-PAni) with the PAni ES resulted in an increase in the high spin polaron population suggesting that it acts as a pseudodopant. The ability of the A-PAni to …


Gel-Carbon Nanotube Materials: The Relationship Between Nanotube Network Connectivity And Conductivity, Naratip Songmee, Pisith Singjai, Marc In Het Panhuis Jan 2010

Gel-Carbon Nanotube Materials: The Relationship Between Nanotube Network Connectivity And Conductivity, Naratip Songmee, Pisith Singjai, Marc In Het Panhuis

Faculty of Science - Papers (Archive)

The electrical resistance of carbon nanotube networks (NNs) prepared from combinations of gellan gum, xanthan gum, Triton X-100, SWNT and MWNT is reported. It is demonstrated that the NN conductivity can be obtained by analysing the resistance of two overlapping NN as a function of their overlap distance. Unexpectedly, the connectivity between two overlapping NN was found to scale with the electrical conductivity over 4 orders of magnitude. Insights into the dependence of inter-NN contact on applied pressure were obtained.


Using Vegetation Units As Salinity Predictors In The Lower Cheliff Algeria, Adda Ababou, Mohammed Chouieb, Mohammed Khader, Khalladi Mederbal, Djamel Saidi Jan 2010

Using Vegetation Units As Salinity Predictors In The Lower Cheliff Algeria, Adda Ababou, Mohammed Chouieb, Mohammed Khader, Khalladi Mederbal, Djamel Saidi

Turkish Journal of Botany

The Lower Cheliff plain is among the largest salted soils in north-western Algeria. In order to establish the relationships between the main soil factors and plant species in this stressed ecosystem, 133 relevés related to soil and vegetation were realized. Soil variables measured included electrical conductivity and calcium carbonate. The 133 relevés were arranged in clusters using k-means classification. The similarity analysis used to examine the variation in vegetation assemblage structure showed significant differences in taxonomical composition among groups of relevés. The phi coefficient of fidelity used then to extract the different vegetation units and to measure species concentration in …


The Influence Of Certain Physical And Chemical Variables On The Seasonal Dynamics Of Phytoplankton Assemblages Of A Source Inlet And The Outlet Of The Shallow Hypertrophic Lake Manyas, Turkey, Kemal Çeli̇k, Tuğba Ongun Jan 2007

The Influence Of Certain Physical And Chemical Variables On The Seasonal Dynamics Of Phytoplankton Assemblages Of A Source Inlet And The Outlet Of The Shallow Hypertrophic Lake Manyas, Turkey, Kemal Çeli̇k, Tuğba Ongun

Turkish Journal of Botany

The relationships between water discharge, temperature, pH, conductivity, turbidity, nitrate, ammonium, phosphate and the seasonal dynamics of phytoplankton assemblages of one of the inlets, which is a source of waste for the lake, and the sole outlet of the shallow hypertrophic Lake Manyas, Turkey, were studied from January 2003 to August 2005. Conductivity, ammonium, nitrate, and phosphate concentrations were higher at the inlet than at the outlet. Diatoms and cyanobacteria were the dominant phytoplankton groups at both stations. Achnantes microcephala (Kütz.) Cleve was dominant throughout the year and Microcystis aeruginosa Kütz. was dominant in summer at both stations. Planktothrix rubescens …


Microbial Growth And Biofilm Formation In Geologic Media Is Detected With Complex Conductivity Measurements, Caroline A. Davis, Estella A. Atekwana, Eliot A. Atekwana, Lee D. Slater, Silvia Rossbach, Melanie R. Mormile Sep 2006

Microbial Growth And Biofilm Formation In Geologic Media Is Detected With Complex Conductivity Measurements, Caroline A. Davis, Estella A. Atekwana, Eliot A. Atekwana, Lee D. Slater, Silvia Rossbach, Melanie R. Mormile

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Complex conductivity measurements (0.1-1000 Hz) were obtained from biostimulated sand-packed columns to investigate the effect of microbial growth and biofilm formation on the electrical properties of porous media. Microbial growth was verified by direct microbial counts, pH measurements, and environmental scanning electron microscope imaging. Peaks in imaginary (interfacial) conductivity in the biostimulated columns were coincident with peaks in the microbial cell concentrations extracted from sands. However, the real conductivity component showed no discernible relationship to microbial cell concentration. We suggest that the observed dynamic changes in the imaginary conductivity (σ″) arise from the growth and attachment of microbial cells and …


Bias Dependence Of The Depletion Layer Width In Semi-Insulating Gaas By Charge Collection Scanning Microscopy, A. Castaldini, A. Cavallini, C. Del Papa, M. Alietti, C. Canali, F. Nava, C. Lanzieri Dec 1994

Bias Dependence Of The Depletion Layer Width In Semi-Insulating Gaas By Charge Collection Scanning Microscopy, A. Castaldini, A. Cavallini, C. Del Papa, M. Alietti, C. Canali, F. Nava, C. Lanzieri

Scanning Microscopy

A procedure for the evaluation of the depletion region width of a Schottky barrier diode made on semi-insulating materials has been assessed and applied to gallium arsenide nuclear detectors. This procedure, which makes use of the optical beam induced current method of charge collection scanning microscopy, allows the direct measurement of the depletion layer width. By taking into account the high resistivity of the material under examination and measuring the diode reverse current, it is possible to evaluate the actual voltage applied at the depletion layer boundaries. It was found that, at low actual bias values, the voltage dependence of …


Diatoms Of Northeastern Iowa Fens, Stephen P. Main, David E. Busch Jan 1992

Diatoms Of Northeastern Iowa Fens, Stephen P. Main, David E. Busch

Journal of the Iowa Academy of Science: JIAS

Analysis of water samples from 10 fens in NE Iowa, collected 13-14 November 1987, revealed a gradient from acid, low conductivity water conditions (pH 5.6, alkalinity 30 mg/I HCO, conductivity 65 μmho, total hardness 30 mg/I Ca) to circumneutral, moderately conductive conditions (pH 7 .2, alkalinity 390 mg/I, conductivity 705 μmho, total hardness 380 mg/I Ca). Three sites along this gradient were sampled 15 May 1988 and 3 September 1988 to evaluate seasonal variation in water conditions. Examination of composite diatom samples collected concurrently with the water samples yielded 150 taxa, of which 14 are new Iowa distributional records and …


Limnological Monitoring Data For Lake Mead During 1988, Suzanne E. Leavitt, Larry J. Paulson, State Of Nevada: Division Of Environmental Protection Apr 1989

Limnological Monitoring Data For Lake Mead During 1988, Suzanne E. Leavitt, Larry J. Paulson, State Of Nevada: Division Of Environmental Protection

Publications (WR)

Limnological monitoring was conducted in Las Vegas Bay and Boulder Basin from April to December of 1988. The purpose of the monitoring was to (i) document possible changes in water quality resulting from decreased phosphorus loading and increased ammonia in Las Vegas Wash, and (ii) establish a data base for evaluating the adequacy of water quality standards.