A test of the predator satiation hypothesis, acorn predator size, and acorn preference

2018 ◽  
Vol 48 (2) ◽  
pp. 237-245 ◽  
Author(s):  
C.H. Greenberg ◽  
S.J. Zarnoch
Keyword(s):  
Removal Rate ◽  
Red Oak ◽  
Positive Trend ◽  
White Oak ◽  
Predator Satiation ◽  
Removal Rates ◽  
Crop Size ◽  
Predator Size ◽  
Satiation Hypothesis ◽  
Acorn Removal

Mast seeding is hypothesized to satiate seed predators with heavy production and reduce populations with crop failure, thereby increasing seed survival. Preference for red or white oak acorns could influence recruitment among oak species. We tested the predator satiation hypothesis, acorn preference, and predator size by concurrently measuring acorn production, mouse abundance, and white versus red oak acorn removal rates in exclosures allowing access by mice (HW), squirrels and smaller-sized vertebrates (WW), or all-sized vertebrates (C) for 12 years. Annual removal rate varied, but virtually all acorns were eventually removed from all exclosure types all years except one. Acorns were removed more slowly from HW than from WW or C exclosures, indicating that large vertebrates were not major acorn consumers, locally. Red and white oak acorn removal rates were similar except in two years, when red oak acorns were removed more rapidly. Removal slowed with increasing acorn crops, suggesting that heavy crops can “swamp” predators. Removal rate was negatively correlated with crop size the previous fall. A positive trend between mouse abundance and crop size the previous fall was evident; abundance decreased sharply the year following crop failures but not after moderate or heavy crops, suggesting that poor crops can dampen acorn predation the following year.

Analysis of organic removal rates in the aerated submerged fixed film process

1998 ◽  
Vol 38 (8-9) ◽  
pp. 213-221 ◽  
Author(s):  
Mohamed F. Hamoda ◽  
Ibrahim A. Al-Ghusain
Keyword(s):  
Pilot Plant ◽  
Removal Rate ◽  
Domestic Wastewater ◽  
Removal Rates ◽  
Hydraulic Loading ◽  
Organic Removal ◽  
Wide Range ◽  
Fixed Film ◽  
Cod Removal Rate ◽  
And Performance

Performance data from a pilot-plant employing the four-stage aerated submerged fixed film (ASFF) process treating domestic wastewater were analyzed to examine the organic removal rates. The process has shown high BOD removal efficiencies (> 90%) over a wide range of hydraulic loading rates (0.04 to 0.68 m3/m2·d). It could also cope with high hydraulic and organic loadings with minimal loss in efficiency due to the large amount of immobilized biomass attained. The organic (BOD and COD) removal rate was influenced by the hydraulic loadings applied, but organic removal rates of up to 104 kg BOD/ m2·d were obtained at a hydraulic loading rate of 0.68 m3/m2·d. A Semi-empirical model for the bio-oxidation of organics in the ASFF process has been formulated and rate constants were calculated based on statistical analysis of pilot-plant data. The relationships obtained are very useful for analyzing the design and performance of the ASFF process and a variety of attached growth processes.

The comparison of trichloroethylene removal rates by methane- and aromatic-utilizing microorganisms

1998 ◽  
Vol 38 (7) ◽  
pp. 19-24 ◽  
Author(s):  
C.-J. Lu ◽  
C. M. Lee ◽  
M.-S. Chung
Keyword(s):  
Cell Concentration ◽  
Removal Rate ◽  
Carbon Sources ◽  
Batch Reactors ◽  
Initial Cell Concentration ◽  
Removal Rates ◽  
Initial Cell ◽  
Toluene Concentration ◽  
Cell Source ◽  
Removal Efficiencies

The comparison of TCE cometabolic removal by methane, toluene, and phenol utilizers was conducted with a series of batch reactors. Methane, toluene, or phenol enriched microorganisms were used as cell source. The initial cell concentration was about 107 cfu/mL. Methane, toluene, and phenol could be readily biodegraded resulting in the cometabolic removal of TCE. Among the three primary carbon sources studied, the presence of phenol provided the best cometabolic removal of TCE. When the concentration of carbon source was 3 mg-C/L, the initial TCE removal rates initiated by methane, toluene, and phenol utilizers were 1.5, 30, and 100 μg/L-hr, respectively. During the incubation period of 80 hours, TCE removal efficiencies were 26% and 96% with the presence of methane and toluene, respectively. However, it was 100% within 20 hours with the presence of phenol. For phenol utilizers, the initial TCE removal rates were about the same, when the phenol concentrations were 1.35, 2.7, and 4.5 mg/L. However, TCE removal was not proportional to the concentrations of phenol. TCE removal was hindered when the phenol concentration was higher than 4.5 mg/L because of the rapid depletion of dissolved oxygen. The presence of toluene also initiated cometabolic removal of TCE. The presence of toluene at 3 and 5 mg/L resulted in similar TCE removal. The initial TCE removal rate was about 95 μg/L-hr at toluene concentrations of 3 and 5 mg/L compared to 20 μg/L-hr at toluene concentration of 1 mg/L.

Relations between carbon removal rates, biofilm size and density of a novel anaerobic reactor: the inverse turbulent bed

2000 ◽  
Vol 41 (4-5) ◽  
pp. 253-260 ◽  
Author(s):  
P. Buffière ◽  
R. Moletta
Keyword(s):  
Removal Rate ◽  
Removal Rates ◽  
Carbon Removal ◽  
Biofilm Growth ◽  
Loading Rates ◽  
Biomass Activity ◽  
High Turbulence ◽  
The One ◽  
High Level ◽  
Very High

An anaerobic inverse turbulent bed, in which the biogas only ensures fluidisation of floating carrier particles, was investigated for carbon removal kinetics and for biofilm growth and detachment. The range of operation of the reactor was kept within 5 and 30 kgCOD· m−3· d−1, with Hydraulic Retention Times between 0.28 and 1 day. The carbon removal efficiency remained between 70 and 85%. Biofilm size were rather low (between 5 and 30 μm) while biofilm density reached very high values (over 80 kgVS· m−3). The biofilm size and density varied with increasing carbon removal rates with opposite trends; as biofilm size increases, its density decreases. On the one hand, biomass activity within the reactor was kept at a high level, (between 0.23 and 0.75 kgTOC· kgVS· d−1, i.e. between 0.6 and 1.85 kgCOD·kgVS · d−1).This result indicates that high turbulence and shear may favour growth of thin, dense and active biofilms. It is thus an interesting tool for biomass control. On the other hand, volatile solid detachment increases quasi linearly with carbon removal rate and the total amount of solid in the reactor levels off at high OLR. This means that detachment could be a limit of the process at higher organic loading rates.

scholarly journals Enhanced Wastewater Treatment by Immobilized Enzymes

2021 ◽  
Author(s):  
Jakub Zdarta ◽  
Katarzyna Jankowska ◽  
Karolina Bachosz ◽  
Oliwia Degórska ◽  
Karolina Kaźmierczak ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Process Optimization ◽  
Organic Pollutants ◽  
Large Scale ◽  
Removal Rate ◽  
Immobilized Enzymes ◽  
Future Research ◽  
Process Conditions ◽  
Removal Rates ◽  
Catalytic Cycles

Abstract Purpose of Review In the presented review, we have summarized recent achievements on the use of immobilized oxidoreductases for biodegradation of hazardous organic pollutants including mainly dyes, pharmaceuticals, phenols, and bisphenols. In order to facilitate process optimization and achievement of high removal rates, effect of various process conditions on biodegradation has been highlighted and discussed. Recent Findings Current reports clearly show that immobilized oxidoreductases are capable of efficient conversion of organic pollutants, usually reaching over 90% of removal rate. Further, immobilized enzymes showed great recyclability potential, allowing their reuse in numerous of catalytic cycles. Summary Collected data clearly indicates immobilized oxidoreductases as an efficient biocatalytic tools for removal of hazardous phenolic compounds, making them a promising option for future water purification. Data shows, however, that both immobilization and biodegradation conditions affect conversion efficiency; therefore, process optimization is required to achieve high removal rates. Nevertheless, we have demonstrated future trends and highlighted several issues that have to be solved in the near-future research, to facilitate large-scale application of the immobilized oxidoreductases in wastewater treatment.

Lubricant Removal, Degradation, and Recovery on Particulate Magnetic Recording Media

1992 ◽  
Vol 114 (1) ◽  
pp. 61-67 ◽  
Author(s):  
V. J. Novotny ◽  
T. E. Karis ◽  
N. W. Johnson
Keyword(s):  
Bulk Viscosity ◽  
Magnetic Recording ◽  
Photoelectron Spectroscopy ◽  
Removal Rate ◽  
Lateral Diffusion ◽  
Recording Media ◽  
Magnetic Recording Media ◽  
Removal Rates ◽  
Linear Chains ◽  
Mechanical Durability

Lubrication of particulate magnetic recording media improves their mechanical durability in sliding and flying by several orders of magnitude compared with unlubricated media. Lubricant removal, degradation, and recovery were studied using microslit scanning Fourier transform infrared spectroscopy and microspot scanning X-ray photoelectron spectroscopy. These techniques measure the total and surface lubricant amounts in the porous film, respectively. Lubricant dynamics were compared for two physisorbed polyperfluoroalkylether lubricants of similar molecular weight but different molecular structure—Y with a CF3 side group and Z with linear chains. The bulk viscosity of Y was about ten times higher than the viscosity of Z. In sliding, the lubricant removal rate of Y was significantly higher than that of Z while in flying the removal rates were reversed. Removal rates in sliding were orders of magnitude higher than those in flying. Effective lateral diffusion coefficients estimated from the rate of lubricant reflow back to the depleted tracks were close to inversely proportional to the bulk viscosity. During sliding and flying both lubricants degraded as evidenced by chemically altered lubricant detected on the surfaces after dissolution of undegraded lubricant.

Mechanisms of High Efficiency and Stabilization of Baffled Constructed Wetland in Treatment of Domestic Sewage

2013 ◽  
Vol 295-298 ◽  
pp. 1057-1061 ◽  
Author(s):  
Chang Bing Ye ◽  
Zhi Ming Zhou ◽  
Ke Zhao ◽  
Qin Liu
Keyword(s):  
Constructed Wetland ◽  
Removal Rate ◽  
Short Circuit ◽  
Domestic Sewage ◽  
Wetland Plants ◽  
Stable Operation ◽  
Removal Rates ◽  
Operational Life ◽  
High Efficient ◽  
Hydraulic Load

To solve the problem of short-circuit of individual current constructed wetland, a baffled constructed wetland was designed and applied to treat domestic sewage by our research group. The wetland plants were composed of Eichhormia crassipes, Oenanthe javanica, Cyperusalternifolius, Phragmites communis and Aquatic. The results of 18 month indicated that the optimal hydraulic load of baffled constructed wetland was 2.0~2.2 m3/(m2•d). At the hydraulic load of 2.0m3/(m2•d), the COD, TN and TP removal rates of baffled constructed wetland could be over 76.40%, 76.12%, 65.37%, respectively, at 24°C. When the temperature decreased to 12°C, the COD, TN, TP removal rates of system decreased to 67.56%、62.75% and 61.33%, respectively; The SS removal rate of the first 6 compartments was about 79.5% and that of system could maintain 87.18% during the operation of system. Based on the results of trial, the mechanisms of extending the baffled constructed wetland's operational life was owed to high efficient SS removal rate of the first 6 compartments which was used as constructed wetland and anaerobic baffled reactor (ABR). As a result, the long-term stable operation of system in treatment of domestic sewage was explained with extending about 5 times service life than that of individual current constructed wetland. The mechanisms of higher efficiency of baffled constructed wetland in treatment of domestic sewage were owed to the longer flow line of system and the up-down flow of domestic sewage makes pollutant more intimate contact with roots of wetland plants.

scholarly journals Oak (Acorn)–Weevil Interactions across an Extensive Latitudinal Gradient in Eastern North America

Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 303
Author(s):  
Michael A. Steele ◽  
Harmony J. Dalgleish ◽  
Shealyn Marino ◽  
Andrew W. Bartlow ◽  
Rachel Curtis ◽  
...  
Keyword(s):  
Latitudinal Gradient ◽  
Quercus Rubra ◽  
Geographic Area ◽  
Eastern North America ◽  
Red Oak ◽  
Quercus Alba ◽  
White Oak ◽  
Opposite Pattern ◽  
Chemical Gradients ◽  
Latitudinal Transect

Recent studies have explored how nut weevils (Curculio and Conotrachelus spp. (Coleoptera: Curculionidae) prey on the fruits (acorns) of oak (Quercus spp.). However, few, if any, have examined these interactions over both an extensive geographic area and over several years. Here, we observed patterns of infestation in acorns of both red oak (Quercus rubra) and white oak (Quercus alba) over an eight-year period along a latitudinal transect, extending as far as 900km, across much of the shared range of these two oak species. Although weevil prevalence did not differ significantly between the two oak species, in red oak, infestation prevalence increased significantly with latitude. In contrast, an opposite pattern was evident in white oak, with the highest infestation prevalence occurring at lower latitudes. One controlled measure of cotyledon damage was significantly lower in acorns of red oak than those of white oak, which may in part be due to larger acorn size at the lower latitudes. Future investigations in this system should focus on the distribution of weevil species (with DNA barcoding) across this range and geographic variation in chemical gradients that likely determine patterns of weevil damage in individual acorns.

Nondestructive Evaluation of Red Oak and White Oak Species

2020 ◽  
Vol 70 (3) ◽  
pp. 370-377
Author(s):  
Cristian Grecca Turkot ◽  
Roy Daniel Seale ◽  
Edward D. Entsminger ◽  
Frederico José Nistal França ◽  
Rubin Shmulsky
Keyword(s):  
Modulus Of Elasticity ◽  
Longitudinal Vibration ◽  
Mechanical Tests ◽  
Modulus Of Rupture ◽  
Red Oak ◽  
Quercus Alba ◽  
White Oak ◽  
Static Modulus ◽  
Static Modulus Of Elasticity ◽  
The Relationship

Abstract The objective of this article is to evaluate the relationship between the dynamic modulus of elasticity (MOEd), which was obtained with acoustic-based nondestructive testing (NDT) methods, and static bending properties of two domestic hardwood oak species. The mechanical properties were conducted using static modulus of elasticity (MOE) and modulus of rupture (MOR) in radial and tangential directions. Mechanical tests were performed according to ASTM D143 on small clear, defect-free specimens from the two tree species: red oak (Quercus rubra) and white oak (Quercus alba). The MOEd was determined by two NDT methods and three longitudinal vibration methods based on the fast Fourier transform. The destructive strength values obtained in this study were within the expected range for these species. The MOE was best predicted by NDT methods for both species but also had a strong capability to predict MOR.

scholarly journals Nut Selection by Captive Blue Jays: Importance of Availability and Implications for Seed Dispersal

The Condor ◽  
2006 ◽  
Vol 108 (2) ◽  
pp. 377-388 ◽  
Author(s):  
Jeffrey E. Moore ◽  
Robert K. Swihart
Keyword(s):  
Correlation Coefficients ◽  
Discrete Choice Models ◽  
Red Oak ◽  
Quercus Alba ◽  
Northern Red Oak ◽  
White Oak ◽  
Large White ◽  
Shagbark Hickory ◽  
Black Oak ◽  
Blue Jays

Abstract We assessed dietary preference of 14 captive Blue Jays (Cyanocitta cristata) for different food types under different conditions of availability. In four separate feeding trials, we provisioned jays with the following: Trial 1, two nuts each of white oak (Quercus alba), pin oak (Q. palustris), black oak (Q. velutina), northern red oak (Q. rubra), and shagbark hickory (Carya ovata); Trial 2, two small and two large red oak acorns; Trial 3, two germinating and two nongerminating white oak acorns; and Trial 4, one large red oak acorn, one large white oak acorn, and one shagbark hickory nut. We used discrete choice models to describe selection under conditions of changing choice sets. Blue Jays displayed a clear preference for pin oak and strong avoidance of red oak acorns when alternative foods were available. White oak and black oak acorns were selected intermediately. Shagbark hickory nuts were never used. Correlation coefficients suggested that preference was inversely related to seed size and the proportion of seed consisting of hard seed coat. In the absence of alternative food items, small red oak acorns were readily taken, whereas large red oak acorns were mostly avoided but still used by some birds. These results highlight the importance of considering food availability when making conclusions about preference, and lend support to the hypothesis that Blue Jays can be important dispersers of even less-preferred oak species. We discuss the potential as well as the limitations for Blue Jays to act as seed dispersers, with respect to postglacial range expansion of fagaceous tree species, and in the context of present-day dispersal in regions where forests are highly fragmented.

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