Fluctuation and Seasonality of Hourly Traffic and Accuracy of Design Hourly Volume Estimates

2008 ◽  
Vol 2049 (1) ◽  
pp. 63-70 ◽  
Author(s):  
David Mario Capparuccini ◽  
Ardeshir Faghri ◽  
Abishai Polus ◽  
Robert E. Suarez
Keyword(s):  
Design Hourly Volume ◽  
Volume Estimates

PETROLOGIC CORRELATIONS TO EXPAND VOLUME ESTIMATES OF THE MIOCENE COUGAR POINT TUFF, YELLOWSTONE HOT SPOT TRACK

2019 ◽  
Author(s):  
Gabriel M. Carbone ◽  
◽  
Christian M. Schrader ◽  
Scott Boroughs ◽  
John A. Wolff
Keyword(s):  
Hot Spot ◽  
Volume Estimates

scholarly journals How to Evaluate Downed Fine Woody Debris Including Logging Residues?

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 881
Author(s):  
Nathalie Korboulewsky ◽  
Isabelle Bilger ◽  
Abdelwahab Bessaad
Keyword(s):  
Wood Density ◽  
Stock Assessment ◽  
Woody Debris ◽  
Diameter Class ◽  
Density Measurements ◽  
Fine Woody Debris ◽  
Forest Inventories ◽  
Test Zone ◽  
Fixed Area ◽  
Volume Estimates

Volume or biomass estimates of downed woody debris are crucial for numerous applications such as forest carbon stock assessment, biodiversity assessments, and more recently for environmental evaluations of biofuel harvesting practices. Both fixed-area sampling (FAS) and line-intersect sampling (LIS) are used in forest inventories and ecological studies because they are unbiased and accurate methods. Nevertheless, most studies and inventories take into account only coarse woody debris (CWD, >10 cm in diameter), although fine woody debris (FWD) can account for a large part of the total downed biomass. We compared the LIS and FAS methods for FWD volume or biomass estimates and evaluated the influence of diameter and wood density measurements, plot number and size. We used a Test Zone (a defined surface area where a complete inventory was carried out, in addition to FAS and LIS), a Pilot Stand (a forest stand where both LIS and FAS methods were applied) and results from 10 field inventories in deciduous temperate forest stands with various conditions and amounts of FWD. Both methods, FAS and LIS, provided accurate (in trueness and precision) volume estimates, but LIS proved to be the more efficient. Diameter measurement was the main source of error: using the mean diameter, even by diameter class, led to an error for volume estimates of around 35%. On the contrary, wood density measurements can be simplified without much influence on the accuracy of biomass estimates (use of mean density by diameter class). We show that the length and number of transects greatly influences the estimates, and that it is better to apply more, shorter transects than fewer, longer ones. Finally, we determined the optimal methodology and propose a simplification of some measurements to obtain the best time-precision trade-off for FWD inventories at the stand level.

scholarly journals Antarctic sea-ice thickness and volume estimates from ice charts between 1995 and 1998

2015 ◽  
Vol 56 (69) ◽  
pp. 383-393 ◽  
Author(s):  
E. Rachel Bernstein ◽  
Cathleen A. Geiger ◽  
Tracy L. Deliberty ◽  
Mary D. Lemcke-Stampone
Keyword(s):  
Sea Ice ◽  
Regional Scale ◽  
Weighted Average ◽  
Ice Thickness ◽  
Average Thickness ◽  
Sea Ice Thickness ◽  
Subjective Analysis ◽  
Stage Of Development ◽  
Volume Estimates ◽  
The Impact

AbstractThis work evaluates two distinct calculations of central tendency for sea-ice thickness and quantifies the impact such calculations have on ice volume for the Southern Ocean. The first calculation, area-weighted average thickness, is computed from polygonal ice features and then upscaled to regions. The second calculation, integrated thickness, is a measure of the central value of thickness categories tracked across different scales and subsequently summed to chosen regions. Both methods yield the same result from one scale to the next, but subsequent scales develop diverging solutions when distributions are strongly non-Gaussian. Data for this evaluation are sea-ice stage-of-development records from US National Ice Center ice charts from 1995 to 1998, as proxy records of ice thickness. Results show regionally integrated thickness exceeds area-weighted average thickness by as much as 60% in summer with as few as five bins in thickness distribution. Year-round, the difference between the two calculations yields volume differences consistently >10%. The largest discrepancies arise due to bimodal distributions which are common in ice charts based on current subjective-analysis protocols. We recommend that integrated distribution be used for regional-scale sea-ice thickness and volume estimates from ice charts and encourage similar testing of other large-scale thickness data archives.

Needle microepiphytes in a Douglas fir canopy: biomass and distribution patterns

1979 ◽  
Vol 57 (9) ◽  
pp. 1000-1007 ◽  
Author(s):  
George C. Carroll
Keyword(s):  
Cell Volume ◽  
Distribution Patterns ◽  
Douglas Fir ◽  
Total Cell ◽  
Microbial Cell ◽  
Microbial Cells ◽  
Cutting Out ◽  
Total Cell Volume ◽  
Volume Estimates ◽  
Cell Volumes

Distribution patterns and total cell-volume estimates for needle microepiphytes are presented for three strata in the canopy of a single old-growth Douglas fir tree. Microbial cell volume was estimated by photographing transverse sections of needles, tracing microbial profiles on Mylar film, cutting out the tracings, and determining the pooled trace weights from various zones of each needle section. Microbial cells are concentrated in the midrib groove and over the stomatal zones of individual needles. Microbial cell volume on the upper needle surfaces increases during the 1st year and declines in subsequent years. Cell volumes on the lower needle surfaces increase from the 1st to the 3rd year and decrease from the 3rd to the 4th year. An increase in microbial cell volume occurs on both upper and lower surfaces from year 7 to year 8. Total microbial cell volume in relation to available needle surface area is greatest in the lower canopy and decreases with increasing height in the canopy. The total volume of microbial cells on needles was estimated to be 1093 cm3 for the entire tree.

Household greywater use practices in Melbourne, Australia

2013 ◽  
Vol 13 (2) ◽  
pp. 294-301 ◽  
Author(s):  
M. Sinclair ◽  
J. O'Toole ◽  
M. Malawaraarachchi ◽  
K. Leder
Keyword(s):  
Urban Areas ◽  
Microbial Contamination ◽  
Tap Water ◽  
Severe Drought ◽  
Urban Water ◽  
Housing Developments ◽  
End Use ◽  
Volume Estimates ◽  
And Storage ◽  
Greywater Reuse

Research on the potential of greywater reuse to reduce urban tap water demand has focused mainly on permanently installed greywater treatment or irrigation systems. These may be readily implemented in new housing developments, but experience in Australia shows their uptake by established households in urban areas is low. The majority of households employ simple and temporary methods for greywater collection and use, but their behaviour has not been well documented. We characterised the greywater use practices of over 1,000 Melbourne households during a 5-year period (2007 to 2011) which included 3 years of severe drought with stringent restrictions on outdoor tap water use. Greywater was most frequently collected from the laundry and bathroom, and generally used within 24 hours. Garden watering was the most common end use, and treatment of greywater to reduce microbial contamination was very rare. Volume estimates by householders suggest that on average around 10% of tap water used in the home was being collected for reuse. When drought conditions and water restrictions eased, over 40% of user households discontinued greywater use. Widespread adoption of permanent greywater collection, treatment and storage systems by households would be required to achieve a lasting effect on urban water consumption.

Neonatal Polycythemia: II. Plasma, Blood, and Red Cell Volume Estimates in Relation to Hematocrit Levels and Quality of Intrauterine Growth

PEDIATRICS ◽  
1981 ◽  
Vol 68 (2) ◽  
pp. 175-182
Author(s):  
Yves W. Brans ◽  
Donna L. Shannon ◽  
Rajam S. Ramamurthy
Keyword(s):  
Birth Weight ◽  
Exchange Transfusion ◽  
Intrauterine Growth Retardation ◽  
Umbilical Vein ◽  
Normal Growth ◽  
Red Cell ◽  
Intrauterine Growth ◽  
The Mean ◽  
Volume Estimates

Volumes of plasma (PV), blood (BV), and red cells (RCV) were estimated within 32 hours of birth in 39 neonates with normal growth, 14 neonates with intrauterine growth retardation, and 20 neonates with macrosomia. Total PV, BV, and RCV increased linearly with birth weight and were unaffected by deviation in the quality of fetal growth. In proportion to body weight, PV/kg, BV/kg, and RCV/kg correlated neither with birth weight nor with the quality of intrauterine growth. Neonates with umbilical vein hematocrit (UV Hct) levels 51% to 60%, 61% to 65%, and 66% to 77% had progressively lower, but not statistically different, mean PV/kg (38.1 ± 4.49, 37.6 ± 5.41, and 34.8 ± 5.16 ml/kg, respectively). On the other hand, they had progressively higher mean BV/kg (90 ± 10.1 vs 101 ± 13.7 ml/kg, P < .002, and vs 110 ± 19.0 ml/kg, P < .001). They also had progressively higher mean RCV/kg (52 ± 7.4, 64 ± 8.7, and 75 ± 16.4 ml/kg, P < .001). Although PV/kg did not correlate with UV Hct, both BV/kg and RCV/kg increased linearly with increasing UV Hct (r = .58 and r = .79, respectively). Volume estimates were repeated after partial exchange transfusion in 29 neonates. Mean UV Hct decreased from 63 ± 5.9% preexchange to 51 ± 5.2% postexchange (P < .001), mean PV increased from 37.7 ± 5.56 to 47.6 ± 7.99 ml/kg (P < .001) and mean RCV decreased from 67 ± 16.5 to 51 ± 12.3 ml/kg (P < .001). Despite precautions to keep the partial exchange isovolemic, mean BV decreased from 105 ± 18.7 to 98 ± 18.0 ml/kg (P = .001) and the mean PV increase (10 ml/kg) was less than the mean RCV decrease (16 ml/kg). These data suggest that neonates with polycythemia have normal PV but their RCV and BV are elevated in direct proportion to UV Hct. "Isovolemic" partial exchange transfusion decreases UV Hct, RCV, and BV and increases PV.

Sign in / Sign up

Export Citation Format

Share Document