The Photographic Determination of Group Size, Composition, and Stability of Coastal Porpoises (Tursiops truncatus)

Science ◽  
1977 ◽  
Vol 198 (4318) ◽  
pp. 755-756 ◽  
Author(s):  
B. WURSIG ◽  
M. WURSIG
Keyword(s):  
Group Size ◽  
Tursiops Truncatus ◽  
Size Composition

Specific Features of Blasting Operations in Mining Minerals in Northern and Arctic Regions of Russia

2021 ◽  
pp. 102-106
Author(s):  
V.A. Tikhonov ◽  
G.A. Dudnik ◽  
S.Yu. Panfilov ◽  
V.V. Zhulikov
Keyword(s):  
Size Composition ◽  
The Arctic ◽  
Physical Parameters ◽  
Arctic Zone ◽  
Arctic Regions ◽  
Priority Task ◽  
Geological Conditions ◽  
The Russian Federation ◽  
Remote Operations

A priority task for facilitating the development of the Arctic zone of the Russian Federation is to design new blasting technologies to be efficiently used in extremely difficult climatic, mining and geological conditions at remote operations. This is further motivated by the fact that up to 40% of Russia's gold reserves, 60–90% of its natural gas resources and 100% of its primary diamond deposits are located in the Arctic zone. The article analyses the problems of blasting operations while developing deposits in the Arctic zone. The main formulations of ordinary explosives are reviewed that allow to solve a number of challenges associated with blasting operations in remote and hard-to-reach Arctic regions. Based on the performed analysis of existing methods, further areas of research are identified that can improve the quality and safety of blasting operations: 1) determination of optimum weight and dimensions of boosters based on ordinary explosives depending on the initiating borehole size; 2) determination of the relation between the particle size / composition of the booster and the detonation velocity; 3) determination of physical parameters of transition from deflagration to detonation and gaining sensitivity to the initiating pulse from the detonator cap by the ordinary explosive compositions.

scholarly journals Determination of Varying Group Sizes for Pooling Procedure

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Wenjun Xiong ◽  
Hongyu Lu ◽  
Juan Ding
Keyword(s):  
Group Size ◽  
Rare Diseases ◽  
Population Heterogeneity ◽  
Sequential Procedure ◽  
Data Driven ◽  
Equal Group ◽  
Essential Step ◽  
Available Information ◽  
Individual Information

Pooling is an attractive strategy in screening infected specimens, especially for rare diseases. An essential step of performing the pooled test is to determine the group size. Sometimes, equal group size is not appropriate due to population heterogeneity. In this case, varying group sizes are preferred and could be determined while individual information is available. In this study, we propose a sequential procedure to determine varying group sizes through fully utilizing available information. This procedure is data driven. Simulations show that it has good performance in estimating parameters.

Influence of artisanal fisheries on the behaviour and social structure of Tursiops truncatus in the South-western Gulf of Mexico

2019 ◽  
Vol 99 (8) ◽  
pp. 1841-1849
Author(s):  
Nataly Morales-Rincon ◽  
Eduardo Morteo ◽  
Christian Alejandro Delfín-Alfonso
Keyword(s):  
Gulf Of Mexico ◽  
Group Size ◽  
Age Structure ◽  
Human Activities ◽  
Tursiops Truncatus ◽  
Bottlenose Dolphins ◽  
Vantage Point ◽  
Competitive Interactions ◽  
Artisanal Fisheries ◽  
Behavioural Plasticity

AbstractBehavioural plasticity in animals is tested whenever competitive interactions for space and/or food resources occur between wildlife and human activities. This study uses the concepts of operational and non-operational interactions between bottlenose dolphins (Tursiops truncatus) and artisanal fisheries in Alvarado, to search for differences in behaviour, age structure and group size. We conducted 20 surveys between 2015 and 2016, and recorded 64 groups by means of scan sampling from either a research boat or a fixed vantage point. Average dolphin group size was small (${\bar{\rm x}}$ = 3.2, SD = 2.2 individuals) and fewer individuals were commonly present when interaction with fisheries occurred. Operational interactions were defined within the first 30 m and occurred mainly with lone individuals (54% recorded from the lighthouse and 82% during surveys); this benchmark also accounted for higher frequencies in locomotion and feeding (χ2 = 83.10; df = 7; P < 0.001). We found a higher rate of new behavioural events for dolphin groups furthest from human activities, as well as a decrease in behaviours that imply greater body exposure as dolphins approach the fishing spots. Age structure and dolphin group size were not different during and in the absence of interaction with fisheries, but most interactions involved male dolphins. Behavioural variations in the dolphins' repertoire are likely a strategy to reduce the risk of injuries or death when interacting with human activities; these dolphins seem to have habituated to or at least tolerate fishing activities within the study area, possibly constituting a sex-biased pressure.

Research on Fuel Migration Phenomenon in the Sintering Process

2013 ◽  
Vol 634-638 ◽  
pp. 857-863
Author(s):  
Ya Ping Mo ◽  
De Qing Zhu ◽  
Jun Li
Keyword(s):  
Grain Size ◽  
Solid Fuel ◽  
Fine Particles ◽  
Vertical Direction ◽  
Size Composition ◽  
Fuel Particle ◽  
Sintering Process ◽  
Material Layer ◽  
Flow Through

In this paper, we use the research methods of sintering cup.On the basis of the determination of solid fuel particle size composition and the distribution in the mixture. During the sintering process, respectively, 5min, 10min, 15min, 20min interrupt the test, by dectecting the distribution of solid fuel in the mixture to study the migration phenomenon of solid fuel during the sintering process. The results showed that: during the sintering process, the main migration of the fuel is the migration of fine particles, including the fuel migration of 0.25-0.5mm grain size, part of the 0.5-1mm grain size and a small amount of-0.25mm grain size,but most of the fuel migrated will be re-adsorbed, about 0.11% of the fuel with the air flow through the material layer, the migration of fuel to ease the state of segregation in the vertical direction along the material layer, so that cause actual participation in the combustion of the fuel content in line along the height direction of the material layer.

scholarly journals Determination of soil grain size composition by measuring apparent weight of float submerged in suspension

2017 ◽  
Vol 31 (1) ◽  
pp. 61-72 ◽  
Author(s):  
Jarosław Kaszubkiewicz ◽  
Witold Wilczewski ◽  
Tibor József Novák ◽  
Przemysław Woźniczka ◽  
Krzysztof Faliński ◽  
...  
Keyword(s):  
Particle Size ◽  
Size Composition ◽  
Digital Transmission ◽  
Weight Changes ◽  
Laser Method ◽  
Particle Size Composition ◽  
Apparent Weight ◽  
High Level ◽  
The Stokes Equation

AbstractTexture is one of the most significant physical properties of soils. Over the years, several methods of its measuring were developed. The paper presents a method for determining the particle size composition of soils, based on the separation of particles in the sedimentation process. Density of suspension is determined on the basis of apparent weight changes of a float submerged in it. The weight of the float suspended on a thin line, at a given depth in the suspension, is measured with a sensitive piezoelectric dynamometer. The Stokes equation is used to calculate the content of soil fractions with equivalent diameters in the range of 0.001 to 0.1 mm. Digital transmission of results from the dynamometer, the temperature sensor and measurements of the distance defining the depth of immersion of the float to the computer enable calculations of particle size composition to be performed automatically. This paper presents the results of measurements of the particle size composition of artificially generated mixtures of ‘silt’ and ‘clay’. The results are compared with results obtained with other methods (including the laser method). A high level of repeatability of the results and satisfactory compatibility in relation to the reference pipette method are noted.

scholarly journals Comparisons of Group-Size, Composition and Movement of Herbivorous Reef Fish in Jamaica and Grand Cayman Island

2020 ◽  
Vol 10 (01) ◽  
pp. 1-15
Author(s):  
Layla Al-Shaer ◽  
Andrew Bloch ◽  
Matthew Draud ◽  
Brandon Baumann ◽  
Murray Itzkowitz
Keyword(s):  
Reef Fish ◽  
Group Size ◽  
Size Composition ◽  
Cayman Island ◽  
Grand Cayman

Group composition and cohesion in sympatric white-tailed deer and mule deer

2003 ◽  
Vol 81 (7) ◽  
pp. 1119-1130 ◽  
Author(s):  
Susan Lingle
Keyword(s):  
Group Size ◽  
Mule Deer ◽  
Size Composition ◽  
Odocoileus Hemionus ◽  
Habitat Conditions ◽  
Small Female ◽  
Habitat Variation ◽  
The Social ◽  
Southern Alberta ◽  
Large Groups

White-tailed deer (Odocoileus virginianus) have been reported to live in smaller groups than mule deer (Odocoileus hemionus). Group size, however, generally varies with habitat conditions, and no comparison has been made between the social structures of the two species living in the same ecological conditions. I compared the size, composition, and stability of groups formed by sympatric whitetails and mule deer living in a prairie habitat in southern Alberta. Seasonal trends were similar for the two species. Females and fawns usually formed small groups during summer. Larger mixed-sex groups became increasingly common during winter, well after the breeding season. Despite the similar seasonal trend, mule deer were significantly more likely than whitetails to occur in relatively large groups composed of both sexes during winter, and whitetails were more likely to occur in small female groups. Mule deer groups were more stable than whitetail groups, and marked mule deer fawns developed strong associations with other known fawns. Habitat variation was limited and was not related to group size. These results show that the composition and cohesion of whitetail and mule deer groups differ, even when the species live in similar circumstances. The differences in grouping behaviour, larger more cohesive groups formed by mule deer than by whitetails, are consistent with those expected to result from the selection pressure of predation.

Sign in / Sign up

Export Citation Format

Share Document