scholarly journals Transfer of Risk elements in soil–bilberry system

2013 ◽  
Vol 32 (2) ◽  
Author(s):  
Margita Kuklová ◽  
Ján Kukla
Keyword(s):  
Forest Ecosystems ◽  
The Other ◽  
Transfer Coefficients ◽  
Limit Values ◽  
Mean Values ◽  
Risk Elements ◽  
Al Content ◽  
L System ◽  
Vaccinium Myrtillus L ◽  
Humus Horizons

AbstractKuklova M., Kukla J.: Transfer of risk elements in soil-bilberry system. Ekologia (Bratislava), Vol. 32, No. 2, p. 211-219, 2013.Transfer of Al, Cr and Ni in the soil-plant (Vaccinium myrtillus L.) system was examined in four forest ecosystems in the localities Muraň (skeli-humic podzols) and Hliniky (dystric cambisols) in the protected zone of the NP Slovensky raj. In case of Al, the transfer coefficients were low, exceeding 1 only in the litter horizon on the damaged plot in the locality Muraň. The Al content in soils was the highest at a depth of 60-70 cm (10 249 mg kg-1) on the undamaged plot in Hliniky. The amounts of Al accumulated in bilberries were higher than the background value in plants, and they made 11-22% of the maximum Al contents detected in Ooh horizons of the studied soils. Cr on the damaged plot in the locality Muraň displayed higher transfer coefficients (range 1.09-11.3) in comparison with the other plots (0.03-0.59). Considering the value representing the maximum Cr amount detected in Ooh horizon in the corresponding locality as 100%, the content of Cr in bilberries growing on the damaged plot in Muraň was 109%, in contrast to 2% on the damaged plot in Hliniky. The concentrations of Ni in soils exceeded limit values in the surface humus horizons on all studied plots. Ni displayed higher transfer coefficients, exceeding 1 only on the damaged plot in the locality Muraň. Bilberries had accumulated 6-28% Ni in the locality Muraň, and 2-6% in the locality Hliniky of the maximum amounts detected in Ooh horizons of soils. The differences in mean values of transfer coefficients for Al, Ni and Cr were statistically significant (p < 0.05).

Modeling mass transfer and substrate utilization in the boundary layer of biofilm systems

1998 ◽  
Vol 37 (4-5) ◽  
pp. 139-147 ◽  
Author(s):  
Harald Horn ◽  
Dietmar C. Hempel
Keyword(s):  
Boundary Layer ◽  
Mass Transfer ◽  
Reynolds Number ◽  
Film Theory ◽  
Substrate Utilization ◽  
The Other ◽  
Concentration Profiles ◽  
Hydrodynamic Conditions ◽  
Time Axis ◽  
Transfer Coefficients

The use of microelectrodes in biofilm research allows a better understanding of intrinsic biofilm processes. Little is known about mass transfer and substrate utilization in the boundary layer of biofilm systems. One possible description of mass transfer can be obtained by mass transfer coefficients, both on the basis of the stagnant film theory or with the Sherwood number. This approach is rather formal and not quite correct when the heterogeneity of the biofilm surface structure is taken into account. It could be shown that substrate loading is a major factor in the description of the development of the density. On the other hand, the time axis is an important factor which has to be considered when concentration profiles in biofilm systems are discussed. Finally, hydrodynamic conditions become important for the development of the biofilm surface when the Reynolds number increases above the range of 3000-4000.

scholarly journals A numerical study of the response of tropical Pacific SST to atmospheric forcing

MAUSAM ◽  
2021 ◽  
Vol 48 (4) ◽  
pp. 657-668
Author(s):  
XIAOMING LIU ◽  
JOHN M. MORRISON ◽  
LIAN XIE
Keyword(s):  
Ocean Circulation ◽  
Numerical Study ◽  
Ocean Model ◽  
Tropical Pacific ◽  
The Other ◽  
Atmospheric Forcing ◽  
Transfer Coefficients ◽  
Low Wind Speed ◽  
Sensitivity Tests ◽  
The Tropical Pacific

Two sets of atmospheric forcing from NCEP/NCAR 40-year reanalysis project, one based on monthly averaged climatological data and the other on 1982-83 monthly averaged data, are used to derive the global Miami Isopycnic Coordinate Ocean Model (MICOM). These two runs are referred to as the climatological experiments and 1982-83 El Nino experiments. Sensitivity tests of tropical Pacific SST to different bulk parameterizations of air-sea heat and momentum fluxes are carried out in the two experiments. Primary results show that constant transfer coefficients                          (1.2 × 10-3) for heat flux greatly overestimate the tropical Pacific SST, whereas the Liu-Katsaros-Businger (Liu et al. 1979) method can significantly improve the SST simulation especially under very low-wind speed conditions. On the other hand, Large and Pond (1982) formulation of the drag coefficient made little difference on the tropical Pacific SST simulation although it might modify the surface ocean circulation. The SST seasonal cycle and interannual variability of tropical Pacific SST are also examined in this study. Since SST is the most important oceanic parameter that provides the link between the atmosphere and the ocean, this evaluation of different parameterization schemes may facilitate future studies on coupling ocean-atmospheric numeric models.    

Effect of grain or silage supplementation on meat quality attributes of cryptorchid lambs grazing lucerne or annual grass-clover pastures

1995 ◽  
Vol 35 (4) ◽  
pp. 461 ◽  
Author(s):  
DL Hopkins ◽  
PJ Holst ◽  
DG Hall
Keyword(s):  
Meat Quality ◽  
Shear Force ◽  
The Other ◽  
Carcass Weight ◽  
Annual Grass ◽  
Eye Muscle ◽  
Mean Values ◽  
Significant Difference ◽  
The Mean ◽  
Ad Libitum

Objective and subjective tests for quality were performed on the meat from 40 cryptorchid second-cross lambs fed lucerne only (L; n = 8), lucerne plus an oat grain supplement ad libitum (LO; n = lo), lucerne plus wilted lucerne silage ad libitum (LS; n = 11), or an oat-lupin grain (3:1) supplement at 90% of ad libitum while grazing dry summer annual pasture (OL; n = 11). All carcasses complied with the Elite lamb specification of weight >22 kg and GR measurement 6-15 mm. There was no significant difference between groups for hot carcass weight, the mean (� s.e) values being 25.1 0.43, 25.2 � 0.36,25.2 � 0.38, and 25.3 � 0.36 kg for L, LS, LO, and OL groups, respectively. When the GR and fat depth over the eye muscle at the 12th rib were adjusted to a common carcass weight of 25.2 kg there was no significant difference between groups. There was no significant difference between groups for pH, or the colour values a*, b*, and L* of the M. longissimus thoracis et lumborum (a* is relative redness, b* relative yellowness, and L* relative lightness). The shear force values for the loin muscle were significantly (P<0.05) greater for lambs from group OL than for those from group LO. Cooking loss for the loin muscle was significantly (P<0.05) greater for OL lambs than all other groups. A comparison of the mean values for aroma and flavour showed the lambs from group OL produced meat that was considered significantly (P<0.05) less desirable for these characteristics, with other groups being similar. Meat from OL-fed lambs was considered oilier and less meaty than meat from lambs fed the other diets. There was a significant (P<0.05) difference in absolute scores between panellists, but their ranking was not affected and there was no panellist x sample interaction. Because many producers use grain supplements such as oats and lupins for finishing lambs on dry forages, further study is recommended that focuses on the interaction between supplement and the base forage.

Interactions between cations and sugars. III. Free energies, enthalpies, and entropies of association of Ca2+, Sr2+, Ba2+, La3+, Gd3+ with D-ribose in water at 25 °C

1987 ◽  
Vol 65 (11) ◽  
pp. 2656-2660 ◽  
Author(s):  
Alfredo Maestre Alvarez ◽  
Nicole Morel-Desrosiers ◽  
Jean-Pierre Morel
Keyword(s):  
Thermodynamic Properties ◽  
Aqueous Solutions ◽  
Equilibrium Constant ◽  
The Other ◽  
Free Energies ◽  
Mean Values ◽  
Enthalpies Of Transfer ◽  
Other Hand ◽  
Solutions Of Electrolytes

The standard enthalpies of transfer of ribose and arabinose from water to aqueous solutions of electrolytes (CaCl2, SrCl2, BaCl2, LaCl3, and GdCl3) have been measured at 25 °C. A method is described to calculate from these data the equilibrium constant and the enthalpy for the association between the cations and the complexing isomers of ribose. Mean values relative to these isomers are given: the constants vary from 2.0 to 4.3 and the enthalpies from −5.9 to −17.9 kJ mol−1 for the different cations studied. The thermodynamic properties of association are not related to the size nor to the charge of the complexed cation in a simple way. On the other hand, the enthalpies of reaction are linearly correlated to the entropies of reaction.

Heat Transfer Model for Condensation in Non-Circular Microchannels

2007 ◽  
Author(s):  
Akhil Agarwal ◽  
Todd M. Bandhauer ◽  
Srinivas Garimella
Keyword(s):  
Heat Transfer ◽  
Acute Angle ◽  
Heat Transfer Model ◽  
The Other ◽  
Transfer Model ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Tube Shape ◽  
Flow Mechanisms ◽  
Circular Microchannels

A model for predicting heat transfer during condensation of refrigerant R134a in horizontal noncircular microchannels is presented. The thermal amplification technique developed and reported in earlier work by the authors is used to measure condensation heat transfer coefficients for six non-circular microchannels (0.424 < Dh < 0.839 mm) of different shapes over the mass flux range 150 < G < 750 kg/m2-s. The channels included barrel-shaped, N-shaped, rectangular, square, and triangular extruded tubes, and a channel with a W-shaped corrugated insert that yielded triangular microchannels. Results from previous work by the authors on condensation flow mechanisms in microchannel geometries were used to interpret the results based on the applicable flow regimes. The effect of tube shape was also considered in deciding the applicable flow regime. A modified version of the annular flow based heat transfer model proposed recently by the authors for circular microchannels, with the required shear stress being calculated from a noncircular microchannel pressure drop model also reported earlier was found to best correlate the present data for square, rectangular and barrel-shaped microchannels. For the other microchannel shapes with sharp acute-angle corners, a mist flow based model from the literature on larger tubes was found to suffice for the prediction of the heat transfer data. These models predict the data significantly better than the other available correlations in the literature.

Evaluation of Agreement Among Routine Methods for Determination of Fluoride in Vegetation: Interlaboratory Collaborative Study

1982 ◽  
Vol 65 (5) ◽  
pp. 1150-1154
Author(s):  
Jay S Jacobson ◽  
John J Troiano ◽  
Christina C Cosentini ◽  
John Evans
Keyword(s):  
Significant Interaction ◽  
Collaborative Study ◽  
Considerable Improvement ◽  
The Other ◽  
Mean Values ◽  
Potentiometric Analysis ◽  
Aoac Official ◽  
Vegetation Samples ◽  
Action Methods

Abstract An interlaboratory collaborative study was conducted to evaluate the performance of methods and laboratories for the measurement of fluoride in vegetation. Samples of 8 plant species containing about 5-200 ppm fluoride were distributed to 40 participants who were instructed to use their routine methods of analysis. Methods which had sufficient participants to allow the inclusion of results in statistical analyses were classified into 3 categories: (1) Willard-Winter method (similar to the AOAC official final action method); (2) semiautomated and potentiometric methods (similar to the 2 AOAC official first action methods); and (3) potentiometric analysis with prior ashing, fusion, and/or distillation (not an approved method). There was a significant interaction of methods with samples caused by 3 of the 8 samples. In the other 5 samples, the Willard-Winter and semiautomated methods gave higher mean values for fluoride content than did the 2 potentiometric methods. Despite considerable improvement in speed and simplicity of fluoride analyses during the last decade, agreement between laboratories has not improved because of the variety of methods and techniques in use, the inherent differences between methods, and, apparently, poor laboratory quality control.

Soil Material Quality and Environmental Potential of Metallically Contaminated Soils

2020 ◽  
Vol 838 ◽  
pp. 164-169
Author(s):  
Juraj Fazekaš ◽  
Danica Fazekašova ◽  
Jana Chovancová
Keyword(s):  
Contaminated Soils ◽  
Agricultural Land ◽  
Mining Activity ◽  
Limit Values ◽  
Soil Material ◽  
Risk Elements ◽  
Average Value ◽  
Potential Index ◽  
Environmental Functions

The paper presents the results of the evaluation of the environmental potential of soils in the area affected by the long-term mining activity. The environmental potential index consists of a numerical expression of the ability to provide water storage, immobilization of risk elements, and immobilization and transformation of organic pollutants. The exceedance of the limit values Hg, Cu, Zn, As, Cd and Pb was found in the soils of the investigated area of central Spiš. The rate of soil immobilization of risk elements is very low to high. The point value expressing the ability of agricultural lands to provide environmental functions is very low to medium in the studied areas, the financial expression of the values of the environmental potentials indexes is in the range of 7 100 to 14 000 € ha-1, while the average value of 1 ha of agricultural land in Slovakia is about 14 200 €.

scholarly journals Fossil Usnea and similar fruticose lichens from Palaeogene amber

2020 ◽  
Vol 52 (4) ◽  
pp. 319-324
Author(s):  
Ulla Kaasalainen ◽  
Jouko Rikkinen ◽  
Alexander R. Schmidt
Keyword(s):  
Forest Ecosystems ◽  
Late Eocene ◽  
The Other ◽  
Epiphytic Lichens ◽  
Unique Type ◽  
General Morphology ◽  
Evolutionary Innovation ◽  
Extant Genus ◽  
Ecological Flexibility ◽  
Minimum Age

AbstractFruticose lichens of the genus Usnea Dill. ex Adans. (Parmeliaceae), generally known as beard lichens, are among the most iconic epiphytic lichens in modern forest ecosystems. Many of the c. 350 currently recognized species are widely distributed and have been used as bioindicators in air pollution studies. Here we demonstrate that usneoid lichens were present in the Palaeogene amber forests of Europe. Based on general morphology and annular cortical fragmentation, one fossil from Baltic amber can be assigned to the extant genus Usnea. The unique type of cortical cracking indirectly demonstrates the presence of a central cord that keeps the branch intact even when its cortex is split into vertebrae-like segments. This evolutionary innovation has remained unchanged since the Palaeogene, contributing to the considerable ecological flexibility that allows Usnea species to flourish in a wide variety of ecosystems and climate regimes. The fossil sets the minimum age for Usnea to 34 million years (late Eocene). While the other similar fossils from Baltic and Bitterfeld ambers cannot be definitely assigned to the same genus, they underline the diversity of pendant lichens in Palaeogene amber forests.

Effects of chest wall compressions in kittens

1982 ◽  
Vol 60 (10) ◽  
pp. 1241-1246 ◽  
Author(s):  
T. Trippenbach ◽  
C. Gaultier ◽  
L. Cooper
Keyword(s):  
Chest Wall ◽  
Chest Compression ◽  
The Other ◽  
Peak Amplitude ◽  
Inspiratory Time ◽  
Chest Compressions ◽  
Mean Values ◽  
Control Value ◽  
Other Hand ◽  
Before And After

Effects of chest compressions on the pattern of breathing were studied in pentobarbital anaesthetized 9- to 11-day-old kittens before and after vagotomy. The chest was compressed by means of a micrometer at three levels (T1–4, T6–8, T9–11). In intact and vagotomized kittens, the group mean values of inspiratory time (tI), expiratory (tE) time, peak amplitude of the integrated phrenic activity (PHR) and its rate of rise (PHR/tI) during compressions were not different from those of the control breaths. On the other hand, in intact kittens during chest compressions variability of all the measured variables significantly increased. In the vagotomized kittens, variability of parameters other than inspiratory time was unaffected. Nevertheless we cannot exclude contribution of extravagal receptors in control of tE. The tE effects could be masked by the increased variability of the control value in vagotomized kittens. The effects of chest compression on the integrated phrenic activity were mostly dependent on the intact vagal feedback.

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