Average relative stem profile comparisons for three size classes of Caribbean pine

1993 ◽  
Vol 23 (12) ◽  
pp. 2594-2598 ◽  
Author(s):  
Paul J. Allen
Keyword(s):  
Form Factor ◽  
Relative Position ◽  
Form Factors ◽  
Size Class ◽  
Polynomial Model ◽  
Relative Height ◽  
Independent Variables ◽  
Size Classes ◽  
The Mean ◽  
Caribbean Pine

A method for determining and comparing average relative stem profiles is described. Under-bark diameters at several points along the stem and the total heights were measured on 572 sample trees of Caribbean pine (Pinuscaribaea Morelet var. hondurensis Barrett & Golfari). For each tree, the total volume and the diameters under bark at several consistent relative positions along the stem (viz. 0.10–0.50 in increments of 0.05) were interpolated. The trees were categorised into three size classes depending on volume. For each tree, a true form factor corresponding to each interpolated relative position was calculated. These form factors were regressed on volume for each size class to determine the most appropriate position along the stem for use in calculating the relative diameters. A polynomial model was fitted to each size class, using relative diameter as the dependent variable and powers of relative height as the independent variables. Differences between the three equations describing the mean relative profiles were statistically significant. Mean errors for the relative diameters are also presented to indicate the accuracy of the three equations.

Fuel weights of understory-grown conifers in southern Oregon

1983 ◽  
Vol 13 (4) ◽  
pp. 648-656 ◽  
Author(s):  
James K. Agee
Keyword(s):  
Pinus Contorta ◽  
Shade Tolerance ◽  
Basal Area ◽  
Size Class ◽  
Regression Equations ◽  
Coniferous Tree ◽  
Independent Variables ◽  
Size Classes ◽  
Coniferous Tree Species ◽  
Foliage Weight

Fuel weight by size classes for five understory coniferous tree species in southern Oregon was estimated using regression equations. Species included Abiesconcolor (Gord. and Glend) Lindl., Abiesmagnified Murr. var. shastensis Lenin., Pinusponderosa Dougl., Pinus contorta Dougl. var. murryana Grev. and Balf., and Tsugamertensiana (Bong.) Carr. Trees ranged from 0.1 to 3 m tall and were selected from "open" and "dense" overstory classes. Live and dead fuels from each tree were segregated into five diameter size classes. Regressions for foliage and total fuel weight are presented using as independent variables groundline diameter, total height, diameter2 × height, and basal area. Coefficients of determination (r2) were high, exceeding 95% for total weight in every case, but tended to decrease as diameter size class increased. Relative shade tolerance of the five species is estimated by comparing open- and dense-grown foliage weight ratios for each species.

Size Distribution in Periphyton

1987 ◽  
Vol 44 (11) ◽  
pp. 2025-2028 ◽  
Author(s):  
Antonella Cattaneo
Keyword(s):  
Size Distribution ◽  
Fish Community ◽  
Size Class ◽  
Size Distributions ◽  
Size Classes ◽  
Rule Of Thumb ◽  
Littoral Fish ◽  
Order Of Magnitude ◽  
The Mean

When periphytic organisms growing on artificial plants were grouped in logarithmically increasing size classes, patterns in the distribution of biomass were consistent over the season and under different grazing regimes, despite taxonornical changes in the dominant taxa of algae and invertebrates. The amount in each size class was not constant, and instead, certain classes tended to have values consistently lower or higher than the mean. The locations of these peaks and troughs in the size distributions coincided with those observed in lake plankton. Despite these irregularities, the hypothesis that the biomass in logarithmic size classes is constant apparently applies at a crude level, for the biomass of most size classes lay within an order of magnitude of the mean. This rule of thumb also applies to the littoral fish community, for the minnow biomass was approximately that in a periphyton size class.

Screening of F1 progeny for selection of superior hybrids in mulberry (Morus spp.) - A simple approach PART I: Screening of seedlings in relation to seed size

2017 ◽  
Vol 6 (2) ◽  
pp. 5256
Author(s):  
Daryoush Shafiei ◽  
Prof. Basavaiah*
Keyword(s):  
Seed Size ◽  
Seedling Survival ◽  
Size Class ◽  
Medium Size ◽  
Screening Process ◽  
Size Classes ◽  
Morus Spp ◽  
In The Beginning ◽  
Selection Of ◽  
Size Grading

In mulberry (Morus spp.), the process of selection of promising hybrids from F1 population requires the screening of a large number of progenies and a long period. To develop a simple and faster approach for screening, studies were conducted using F1 seeds of two crosses. The details of screening studies conducted in relation to seed-size and seedling-size are reported separately in two parts. In this part, the F1 seeds were size-graded as small, medium and large seeds; their progenies were raised separately and screened in nursery. There was a considerable degree of variation in size of seeds and medium-size class seeds were in high percentage in both the crosses. The length, width and weight of seeds were also varied between the seed size classes significantly in both the crosses. The seed size classes differ with high significance in shoot length and Root collar diameter and also differ significantly in root length and weight of seedlings. The positive correlation between the seed size and growth of seedlings, seed size and germination, seed size and seedling survival in nursery indicated that size-grading of seeds and rejection of small seeds in the beginning of screening process may help to increase the efficiency of screening by increasing the chances of getting superior hybrids from limited progenies. However, confirmation on the performance of large seedlings from small seed size class may help to draw conclusion. Hence, the studies are continued with size- grading of seedlings in the next part of screening study.

scholarly journals Ethnic variation in medial orbital wall anatomy and its implications for decompression surgery

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Minhui Amy Chan ◽  
Farah Ibrahim ◽  
Arjunan Kumaran ◽  
Kailing Yong ◽  
Anita Sook Yee Chan ◽  
...  
Keyword(s):  
Relative Position ◽  
Ethmoid Sinus ◽  
Decompression Surgery ◽  
Ethnic Variation ◽  
Sinus Wall ◽  
Orbital Wall ◽  
Mean Width ◽  
Significant Difference ◽  
The Mean ◽  
Medial Orbital Wall

Abstract Background To describe the inter-ethnic variation in medial orbital wall anatomy between Chinese, Malay, Indian and Caucasian subjects. Methods Single-centre, retrospective, Computed Tomography (CT)-based observational study. 20 subjects of each ethnicity, were matched for gender and laterality. We excluded subjects younger than 16 years and those with orbital pathology. OsiriX version 8.5.1 (Pixmeo., Switzerland) and DICOM image viewing software CARESTREAM Vue PACS (Carestream Health Inc., USA) were used to measure the ethmoidal sinus length, width and volume, medial orbital wall and floor angle and the relative position of the posterior ethmoid sinus to the posterior maxillary wall. Statistical analyses were performed using Statistical Package for Social Sciences version 25.0 (IBM, USA). Results There were 12 males (60 %) in each group, with no significant difference in age (p = 0.334–0.994). The mean ethmoid sinus length in Chinese, Malay, Indian and Caucasian subjects, using the Chinese as reference, were 37.2, 36.9, 38.0 and 37.4mm, the mean width was 11.6, 10.5, 11.4 and 10.0mm (p = 0.020) and the mean ethmoid sinus volume were 3362, 3652, 3349 and 3898mm3 respectively. The mean medial orbital wall and floor angle was 135.0, 131.4, 131.0 and 136.8 degrees and the mean relative position of posterior ethmoid sinus to posterior maxillary wall were − 2.0, -0.2, -1.5 and 1.6mm (p = 0.003) respectively. Conclusions No inter-ethnic variation was found in decompressible ethmoid sinus volume. Caucasians had their posterior maxillary sinus wall anterior to their posterior ethmoidal walls unlike the Chinese, Malay and Indians. Awareness of ethnic variation is essential for safe orbital decompression.

The influence of the nuclear and atomic form factors on the muon bremsstrahlung cross section

1968 ◽  
Vol 46 (10) ◽  
pp. S377-S380 ◽  
Author(s):  
A. A. Petrukhin ◽  
V. V. Shestakov
Keyword(s):  
Form Factor ◽  
Cross Section ◽  
Born Approximation ◽  
Form Factors ◽  
Experimental Results ◽  
Simple Analytical Expression ◽  
Nuclear Form Factor ◽  
The Cross ◽  
Atomic Electrons ◽  
Bremsstrahlung Process

The cross section for the muon bremsstrahlung process is calculated as a function of the nuclear form factor in the Born approximation following the Bethe and Heitler theory. The influence of the nuclear form factor is greater than that taken by Christy and Kusaka. The simple analytical expression for the effect of the screening of the atomic electrons is found. The influence of a decrease in the cross section upon the interpretation of some experimental results is estimated.

scholarly journals The Abundance of Microcystin-Producing Genotypes Correlates Positively with Colony Size in Microcystis sp. and Determines Its Microcystin Net Production in Lake Wannsee

2003 ◽  
Vol 69 (2) ◽  
pp. 787-795 ◽  
Author(s):  
Rainer Kurmayer ◽  
Guntram Christiansen ◽  
Ingrid Chorus
Keyword(s):  
Growth Rate ◽  
Colony Size ◽  
Population Growth Rate ◽  
Size Class ◽  
Net Production ◽  
Cell Numbers ◽  
Size Classes ◽  
Key Factor ◽  
Genotype Composition ◽  
Working Hypotheses

ABSTRACT The working hypotheses tested on a natural population of Microcystis sp. in Lake Wannsee (Berlin, Germany) were that (i) the varying abundance of microcystin-producing genotypes versus non-microcystin-producing genotypes is a key factor for microcystin net production and (ii) the occurrence of a gene for microcystin net production is related to colony morphology, particularly colony size. To test these hypotheses, samples were fractionated by colony size with a sieving procedure during the summer of 2000. Each colony size class was analyzed for cell numbers, the proportion of microcystin-producing genotypes, and microcystin concentrations. The smallest size class of Microcystis colonies (<50 μm) showed the lowest proportion of microcystin-producing genotypes, the highest proportion of non-microcystin-producing cells, and the lowest microcystin cell quotas (sum of microcystins RR, YR, LR, and WR). In contrast, the larger size classes of Microcystis colonies (>100 μm) showed the highest proportion of microcystin-producing genotypes, the lowest proportion of non-microcystin-producing cells, and the highest microcystin cell quotas. The microcystin net production rate was nearly one to one positively related to the population growth rate for the larger colony size classes (>100 μm); however, no relationship could be found for the smaller size classes. It was concluded that the variations found in microcystin net production between colony size classes are chiefly due to differences in genotype composition and that the microcystin net production in the lake is mainly influenced by the abundance of the larger (>100-μm) microcystin-producing colonies.

Mean Temperature Difference Charts for Air Coolers

1983 ◽  
Vol 105 (3) ◽  
pp. 592-597 ◽  
Author(s):  
A. Pignotti ◽  
G. O. Cordero
Keyword(s):  
Heat Transfer ◽  
Heat Capacity ◽  
Temperature Difference ◽  
Optimization Technique ◽  
Independent Variables ◽  
Mean Temperature ◽  
Air Cooler ◽  
The Mean ◽  
The One ◽  
Water Ratio

Computer generated graphs are presented for the mean temperature difference in typical air cooler configurations, covering the combinations of numbers of passes and rows per pass of industrial interest. Two sets of independent variables are included in the graphs: the conventional one (heat capacity water ratio and cold fluid effectiveness), and the one required in an optimization technique of widespread use (hot fluid effectiveness and the number of heat transfer units). Flow arrangements with side-by-side and over-and-under passes, frequently found in actual practice, are discussed through examples.

Quality of soil from the nickel mining area of Southeast Sulawesi, Indonesia, engineered using earthworms (Pheretima sp.)

2021 ◽  
Vol 8 (4) ◽  
pp. 2995-3005
Author(s):  
Hasbullah Syaf ◽  
Muhammad Albar Pattah ◽  
Laode Muhammad Harjoni Kilowasid
Keyword(s):  
Tap Water ◽  
Soil Aggregates ◽  
Aggregate Size ◽  
Mining Area ◽  
Size Class ◽  
Soil Conditions ◽  
Total N ◽  
Organic C ◽  
Size Classes ◽  
Nickel Mining

Earthworms (Pheretima sp.) could survive under abiotic stress soil conditions. Furthermore, their activities as ecosystem engineers allow for the creation of soil biostructures with new characteristics. Therefore, this study aimed to investigate the effect of the abundance of Pheretima sp. on the aggregate size, physicochemistry, and biology of the topsoil from the nickel mining area of Southeast Sulawesi, Indonesia. It was carried out by first grouping their abundance into zero, two, four, six, and eight individuals per pot and then carrying out tests. The Pheretima sp. were then released onto the surface of the topsoil and mixed with biochar that was saturated with tap water in the pot overnight. The results showed that the abundance of the species had a significant effect on the size class distribution, and aggregate stability of the soil. Furthermore, the size of the soil aggregates formed was dominated by the size class 2.83 - 4.75 mm under both dry and wet conditions. Under dry conditions, three size classes were found, while under wet conditions, there were five size classes. The results also showed that the highest and lowest stability indexes occurred with zero and eight Pheretima sp., respectively. Furthermore, the abundance had a significant effect on pH, organic C, total N, CEC, and total nematodes. However, it had no significant effect on the total P, C/N ratio, total AMF spores, and flagellate. The highest soil pH occurred with zero Pheretima sp., while with six and two members of the species, the total nematode was at its highest and lowest populations, respectively. Therefore, it could be concluded that the species was able to create novel conditions in the topsoils at the nickel mining area that were suitable for various soil biota.

Diet of the endangered spirlin (Alburnoides bipunctatus) at the centre of its distribution in Europe

2018 ◽  
Vol 69 (11) ◽  
pp. 1712
Author(s):  
L. Marszał ◽  
M. Grzybkowska ◽  
D. Błońska ◽  
J. Leszczyńska ◽  
M. Przybylski
Keyword(s):  
Resource Use ◽  
Diet Composition ◽  
Feeding Habits ◽  
Open Water ◽  
Size Class ◽  
Habitat Segregation ◽  
Chironomid Larvae ◽  
Size Classes ◽  
Taxonomic Groups ◽  
Distribution In Europe

The feeding habits of spirlin Alburnoides bipunctatus were investigated in a tributary of the River Vistula (Poland). To evaluate size-related patterns of resource use, fish were assigned to three size classes, defined according to size at first maturation: small (29–70-mm total length, TL), medium (71–90mm TL) and large (91–104mm TL). There was a significant ontogenetic shift in the feeding pattern among size classes, marked by differences in the proportion of the main taxonomic groups of prey consumed: small spirlin primarily consumed chironomid larvae, whereas medium and large spirlin showed a preference for Coleoptera, Ephemeroptera and imagines of unidentified insects. The proportion of prey taken from the water column was significantly lower for small- than medium- and large-sized spirlin. This difference was attributed to the benthic habits of small spirlin compared with medium and large spirlin. The shift to open water feeding in spirlin corresponded with sexual maturation, with habitat segregation between the smallest size class (comprising juveniles) and larger size classes (mature individuals). Size-specific changes in the diet composition of this species have not previously been documented.

Helm model interpretation of 16O form factors: application to pion photoproduction and muon capture

1980 ◽  
Vol 58 (1) ◽  
pp. 48-62 ◽  
Author(s):  
R. D. Graves ◽  
B. A. Lamers ◽  
Anton Nagl ◽  
H. Überall ◽  
V. Devanathan ◽  
...  
Keyword(s):  
Form Factor ◽  
Electron Scattering ◽  
Form Factors ◽  
Muon Capture ◽  
Physical Parameters ◽  
Medium Energy ◽  
Model Interpretation ◽  
Charged Pions ◽  
Transition Densities ◽  
Energy Processes

The available experimental data for the form factors of the T = 1 levels in 16O, obtained from electron scattering at low (Darmstadt), medium (Tohoku), and high momentum transfer (Stanford), are interpreted by the generalized Helm model. This phenomenological model reduces the form factor description of each level to the listing of a few physical parameters, i.e., the radius and smearing width of the transition densities of charge (current) and magnetization, and their corresponding strength constants. Its parameters having been determined by the form factor fits, the model may then be used to predict the results of other medium energy processes; this is done here for the photoproduction of charged pions and for muon capture in16O.

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