Factors Influencing the Light Environment in Cootes Paradise, Hamilton Harbour, and Other Coastal Marshes of Lake Ontario

1996 ◽  
Vol 31 (3) ◽  
pp. 553-576 ◽  
Author(s):  
Eric P.S. Sager
Keyword(s):  
Critical Period ◽  
Suspended Solids ◽  
Inorganic Material ◽  
Light Attenuation ◽  
Light Environment ◽  
Coastal Marshes ◽  
Causal Factors ◽  
Macrophyte Community ◽  
Different Types ◽  
Germination And Growth

Abstract A common characteristic in many degraded coastal marshes of the Great Lakes is the absence of a submersed macrophyte community. A poor light environment due to high levels of turbidity is one factor which has been implicated in inhibiting their recovery. The overall purpose of this study was to examine the relative impacts of suspended materials on the light environment in turbid areas during the critical period of macrophyte germination and growth and causal factors. It also addresses the components of turbidity, partitioning these into three different types: algae (as measured by chlorophyll a), detritus and inorganic material. Through the use of least squares multiple regression, it was found that suspended inorganic material was playing the largest role in increasing light attenuation at all four sites over the course of the study. It was also found that the majority of suspended solids was made up of inorganic material. The sources of this material are discussed.

Seagrass depth range and water quality in southern Moreton Bay, Queensland, Australia

1996 ◽  
Vol 47 (6) ◽  
pp. 763 ◽  
Author(s):  
EG Abal ◽  
WC Dennison
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Suspended Solids ◽  
Light Attenuation ◽  
River Mouth ◽  
Total Suspended Solids ◽  
Quality Parameters ◽  
Depth Range ◽  
Moreton Bay ◽  
A Site

Correlations between water quality parameters and seagrass depth penetration were developed for use as a biological indicator of integrated light availability and long-term trends in water quality. A year-long water quality monitoring programme in Moreton Bay was coupled with a series of seagrass depth transects. A strong gradient between the western (landward) and eastern (seaward) portions of Moreton Bay was observed in both water quality and seagrass depth range. Higher concentrations of chlorophyll a, total suspended solids, dissolved and total nutrients, and light attenuation coefficients in the water column and correspondingly shallower depth limits of the seagrass Zostera capricorni were observed in the western portions of the bay. Relatively high correlation coefficient values (r2 > 0.8) were observed between light attenuation coefficient, total suspended solids, chlorophyll a, total Kjeldahl nitrogen and Zostera capricorni depth range. Low correlation coefficient values (r2 < 0.8) between seagrass depth range and dissolved inorganic nutrients were observed. Seagrasses had disappeared over a five-year period near the mouth of the Logan River, a turbid river with increased land use in its watershed. At a site 9 km from the river mouth, a significant decrease in seagrass depth range corresponded to higher light attenuation, chlorophyll a, total suspended solids and total nitrogen content relative to a site 21 km from the river mouth. Seagrass depth penetration thus appears to be a sensitive bio-indicator of some water quality parameters, with application for water quality management.

Patterns of gross deposition in reservoirs enriched in inorganic tripton

2001 ◽  
Vol 58 (11) ◽  
pp. 2177-2188 ◽  
Author(s):  
Steven W Effler ◽  
Carol M Matthews (Brooks) ◽  
David A Matthews
Keyword(s):  
New York ◽  
Suspended Solids ◽  
Inorganic Material ◽  
Settling Velocity ◽  
Particulate Phosphorus ◽  
Overlying Water ◽  
Longitudinal Gradients ◽  
The Individual ◽  
Carbon Particulate ◽  
Inorganic Components

Magnitudes and patterns in the deposition of chlorophyll (Chl), organic carbon, particulate phosphorus (PP), and suspended solids are documented for seven New York reservoirs based on analyses of metalimnetic and near-bottom sediment trap collections. Inorganic material dominated the trap collections and caused a decoupling of the downward fluxes of Chl and PP because of major contributions of inorganic components to P deposition. These contributions were manifested in the stoichiometry of trap collections, the much higher estimates of settling velocity (SV) for PP compared with Chl, and differences in patterns of Chl and PP deposition within individual reservoirs and among these systems. Most of the deposited phosphorus in these reservoirs (71–98%) was associated with nonphytoplankton particles. In contrast to the other constituents, the estimates of SV for Chl were lower and more uniform; nearly 50% of the individual estimates (n = 188) were between 0.15 and 0.25 m·day–1. Longitudinal gradients in sediment deposition occurred as a result of gradients in both overlying water concentrations and settling characteristics of the particles. Seasonal and vertical patterns in trap collections and budget calculations indicate that resuspension contributed to deposition, to varying extents, in all of the reservoir basins.

Modelling the clogging of coarse gravel and tire shreds in column tests

2007 ◽  
Vol 44 (11) ◽  
pp. 1273-1285 ◽  
Author(s):  
R. Kerry Rowe ◽  
Dan Babcock
Keyword(s):  
Laboratory Tests ◽  
Suspended Solids ◽  
Good Prediction ◽  
Column Tests ◽  
Average Grain Size ◽  
Tire Shreds ◽  
Different Types ◽  
Monod Kinetic ◽  
Coarse Gravel ◽  
Waste Leachate

A combination of data from laboratory tests and modelling is reported for both coarse gravel (19–38 mm) and two types of tire shred permeated with municipal solid waste leachate. It is suggested that the dispersivity of both the coarse gravel (initially about 4 mm) and tire shreds (initially about 45 mm) increases as the porosity of the drainage media is reduced because of clogging. The detachment of biofilm caused by growth and shear is examined and both are found to influence clogging. The average grain size estimated based on the measured surface area of the particles within a unit volume is shown to provide a good prediction of the rate of clogging for gravel and a conservative prediction for tire shreds. The size and density of suspended solids in leachate is found to significantly influence clogging rates. It is shown that Monod kinetic constants deduced for gravel at 27 °C give a good prediction of clogging for two different types of tire shred at the same temperature. Calibrated parameters used with the BioClog model are shown to give good fits to the porosity of both gravel and tire shred drainage material in laboratory column tests over time periods of up to 2 years.

scholarly journals Paranoia and Grandiosity in the General Population: Differential Associations With Putative Causal Factors

2021 ◽  
Vol 12 ◽  
Author(s):  
Julia M. Sheffield ◽  
Aaron P. Brinen ◽  
Daniel Freeman
Keyword(s):  
General Population ◽  
Sleep Quality ◽  
Sleep Disturbance ◽  
Paranoid Ideation ◽  
Causal Factors ◽  
Contributory Factors ◽  
Delusional Ideation ◽  
Different Types ◽  
Psychological Models

Worry, negative self-beliefs, and sleep disturbance have been identified as contributory factors to the onset, maintenance, and severity of paranoia. We tested the specificity of these contributory factors to paranoia compared to grandiosity, a different type of delusional ideation. Data were used from 814 adults from the Nathan Kline Institute-Rockland (NKI-Rockland) study, a general population dataset. Paranoid and grandiose delusional ideation was assessed using the Peters Delusions Inventory (PDI-21) and correlated with self-reported worry (n = 228), negative self-beliefs (n = 485), and sleep quality (n = 655). Correlations were compared using Fisher's r-to-z transform to examine whether the magnitude of relationships differed by delusion type. Paranoia was significantly associated with worry, negative self-belief, and sleep quality. Grandiosity demonstrated significantly weaker relationships with worry and negative self-beliefs. Relationships with sleep quality were similar. We replicate previous reports that worry, negative self-beliefs and sleep quality are associated with paranoid ideation in the general population. We extend these findings by demonstrating that these contributory factors, particularly worry and negative self-beliefs, are associated with paranoid ideation to a greater extent than grandiosity. This suggests a degree of specificity of contributory factors to different types of delusional thinking, supporting the pursuit of specific psychological models and treatments for each delusion type.

scholarly journals Low thermal conductivity in a modular inorganic material with bonding anisotropy and mismatch

Science ◽  
2021 ◽  
pp. eabh1619
Author(s):  
Quinn D. Gibson ◽  
Tianqi Zhao ◽  
Luke M. Daniels ◽  
Helen C. Walker ◽  
Ramzy Daou ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Room Temperature ◽  
Inorganic Material ◽  
Phonon Dispersion ◽  
Spatial Arrangement ◽  
Vibrational Modes ◽  
Crystalline Materials ◽  
Low Thermal Conductivity ◽  
Transverse Modes ◽  
Different Types

The thermal conductivity of crystalline materials cannot be arbitrarily low as the intrinsic limit depends on the phonon dispersion. We used complementary strategies to suppress the contribution of the longitudinal and transverse phonons to heat transport in layered materials containing different types of intrinsic chemical interface. BiOCl and Bi2O2Se encapsulate these design principles for longitudinal and transverse modes respectively, and the bulk superlattice material Bi4O4SeCl2 combines these effects by ordering both interface types within its unit cell to reach an extremely low thermal conductivity of 0.1 W K−1 m−1 at room temperature along its stacking direction. This value comes within a factor of four of air. We demonstrated that chemical control of the spatial arrangement of distinct interfaces can synergically modify vibrational modes to minimize thermal conductivity.

Case Studies of Two Second Language Learners of English

2019 ◽  
Vol 9 (10) ◽  
pp. 15-21
Author(s):  
Kamila alhadi Algwil
Keyword(s):  
Second Language ◽  
Language Learners ◽  
Cultural Context ◽  
Critical Period ◽  
Second Language Learners ◽  
Cognitive Theory ◽  
Cultural Theory ◽  
Oral Communication ◽  
Different Types ◽  
Main Factors

This study focuses on the factors that affect learners in learning English as a second language and the different types of errors. It also focuses on the strategies that are followed by the two second language learners during a three-month period and how they may help to understand the behaviourism theory, cognitive theory, and socio-cultural theory. The aims of the study are to explore how learners learn a second language, to highlight methods that they use to learn English and to examine their abilities in English. The methods that are used for data collection are an interview, a grammar test, samples of writing in English, and observation. The findings are analysed in relation to behaviourism theory, cognitive theory, and socio-cultural theory. The findings reveal that age, motivation, and personality are the main factors that affect the two learners. It appears that the Critical Period Hypothesis may have an impact only in pronunciation and oral communication rather than grammatical ability. The study also shows that the socio-cultural context is the most essential theory in learning a second language as it considers mental processes and the socio-cultural context. 

GROSS SOLIDS IN SEWER SYSTEMS: TEMPORAL AND CATCHMENT BASED RELATIONSHIPS

1994 ◽  
Vol 30 (1) ◽  
pp. 63-71 ◽  
Author(s):  
C. Jefferies ◽  
R. M. Ashley
Keyword(s):  
Suspended Solids ◽  
Daily Variation ◽  
Critical Factor ◽  
Observation Point ◽  
Dry Period ◽  
Sewer Systems ◽  
Combined Sewer ◽  
Predictive Methods ◽  
Different Types ◽  
High Degree

The behaviour of gross and visible solids was studied at two combined sewer overflow sites using the WRc Gross Solids Sampler. At one of the sites the daily variation of gross solids during dry weather was determined. There was found to be close correspondence between the variations of gross and suspended solids in the sewage. A relationship was developed between the load of gross solids and that of suspended solids at the observation point in dry weather. This relationship is presented for use with other predictive methods. A chart is presented which differentiates with a high degree of reliability the gross solids production of two different types of catchments, one being a collector sewer catchment, the other being a trunk. The rate of gross solids production has been found to be a critical factor in differentiating between the catchments. A consistent and further differentiation in the accumulation of gross solids is presented on the basis of antecedent dry period, greater than 24h allowing considerably greater accumulations than shorter dry periods.

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