Alberta bolide of June 1, 1982: interpretation of photographic and seismic records

1989 ◽  
Vol 26 (7) ◽  
pp. 1350-1355 ◽  
Author(s):  
G. L. Cumming
Keyword(s):  
Horizontal Plane ◽  
National Research Council ◽  
Average Height ◽  
Apparent Velocity ◽  
Zero Curvature ◽  
Seismic Recording ◽  
Seismic Records ◽  
Cold Lake ◽  
Front Curvature

Passage of a bright bolide northeast of Edmonton near midnight on the evening of June 1, 1982, was recorded both photographically by three cameras of the Meteorite Observation and Recovery Project of the National Research Council of Canada and by seismic recording stations at Edmonton and Cold Lake. The photographic data indicate a path towards the northwest at an average height of about 80 km and an average speed of 28 km/s. The Cold Lake data make possible the determination of direction and velocity of approach of the sound wave as well as wave-front curvature in the horizontal plane. The data indicate an essentially zero curvature and a speed across the array of 337.8 m/s for the sound arrival.Wave-front curvature indicates a line source, being the nearly cylindrical shock wave from the hypervelocity bolide. Directions of approach at both Cold Lake and Edmonton, however, seem to indicate a direction more consistent with the end of the brightest segment of the meteor photograph.The discrepancy is not resolved at present, nor is the very slow apparent velocity towards both Cold Lake and Edmonton as derived from the traveltimes to each of the seismic stations.

Determination of seismic site classification of seismic recording stations in the Himalayan region using HVSR method

2019 ◽  
Vol 116 ◽  
pp. 304-316 ◽  
Author(s):  
P. Anbazhagan ◽  
K.N. Srilakshmi ◽  
Ketan Bajaj ◽  
Sayed S.R. Moustafa ◽  
Nassir S.N. Al-Arifi
Keyword(s):  
Himalayan Region ◽  
Site Classification ◽  
Seismic Recording ◽  
Hvsr Method

scholarly journals SPATIAL-TEMPORAL ANALYSIS OF SEISMIC WAVE-FIELD FROM THE DISTRIBUTED MINING EXPLOSION

2019 ◽  
Vol 4 (1) ◽  
pp. 141-148
Author(s):  
Sergey Efimov
Keyword(s):  
Wave Field ◽  
Seismic Wave ◽  
Temporal Analysis ◽  
Seismic Signal ◽  
Environmental Risks ◽  
Time Analysis ◽  
Seismic Recording ◽  
Seismic Records ◽  
Seismic Wave Field ◽  
Spatial Temporal Analysis

The article presents a space-time analysis of the seismic wave from a distributed career explosion. The method of direct measurement based on the dynamic model of the wave field is used to form an image of the seismic wave field in the field of quarry explosions. The efficiency of the proposed method is shown by the example of experimental seismic recording processing. The program "Nelumbo" is used to visualize the seismic field, which on the basis of experimental seismic records allows to form an image of the wave field in the space of the hemisphere, the center of which corresponds to the position of the seismometer (registration point). The algorithm of the program "Nelumbo" is based on the Huygens – Fresnel principle and Kirchhoff's theorem. The algorithm of the program allows to allocate from record of a seismic signal frames of a certain duration and to form the image of a wave field in space of a solid angle dimension π. This approach can be used as a tool to analyze the nature of the development of disturbances in the environment and the analysis of environmental risks in the production of blasting.

scholarly journals Fast Determination of Earthquake Depth Using Seismic Records of a Single Station, Implementing Machine Learning Techniques

2018 ◽  
Vol 38 (2) ◽  
pp. 91-103 ◽  
Author(s):  
Luis Hernán Ochoa Gutierrez ◽  
Luis Fernando Niño Vasquez ◽  
Carlos Alberto Vargas Jimenez
Keyword(s):  
Warning System ◽  
Machine Learning Techniques ◽  
Support Vector ◽  
Fast Determination ◽  
Learning Techniques ◽  
Single Station ◽  
Time Signals ◽  
Seismic Records ◽  
The City

The purpose of this research is to apply a new approach to make a fast determination of earthquake depth using seismic records of the “El Rosal” station, near to the city of Bogota – Colombia, by applying support vector machine regression (SVMR). The algorithm was trained with descriptors obtained from time signals of 863 seismic events acquired between January 1998 and October 2008; only earthquakes with magnitude ≥ 2 were contemplated, filtering its signals to remove diverse kind of noises not related to earth tremors. During training stages of SVMR several combinations of kernel function exponent and complexity factor were considered for time signals of 5, 10 and 15 seconds along with earthquake magnitudes of 2.0, 2.5, 3.0 and 3.5 (Ml). The best classification of SVMR was obtained using time signals of 15 seconds and earthquake magnitudes of 3.5 with kernel exponent of 10 and complexity factor of 2, showing accuracy of 0.6 ± 16.5 kilometers, which is good enough to be used in an early warning system for the city of Bogota. It is recommended to provide this model with a previous phase of deep-shallow classification.

scholarly journals Free Interfaces at the Tips of the Cilia in the One-Dimensional Periciliary Layer

Mathematics ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1961
Author(s):  
Kanognudge Wuttanachamsri
Keyword(s):  
Mathematical Model ◽  
Exact Solution ◽  
Free Boundary ◽  
Horizontal Plane ◽  
Numerical Solutions ◽  
Numerical Results ◽  
Brinkman Equation ◽  
Average Height ◽  
Free Interface ◽  
The Mathematical Model

Cilia on the surface of ciliated cells in the respiratory system are organelles that beat forward and backward to generate metachronal waves to propel mucus out of lungs. The layer that contains the cilia, coating the interior epithelial surface of the bronchi and bronchiolesis, is called the periciliary layer (PCL). With fluid nourishment, cilia can move efficiently. The fluid in this region is named the PCL fluid and is considered to be an incompressible, viscous, Newtonian fluid. We propose there to be a free boundary at the tips of cilia underlining a gas phase while the cilia are moving forward. The Brinkman equation on a macroscopic scale, in which bundles of cilia are considered rather than individuals, with the Stefan condition was used in the PCL to determine the velocity of the PCL fluid and the height/shape of the free boundary. Regarding the numerical methods, the boundary immobilization technique was applied to immobilize the moving boundaries using coordinate transformation (working with a fixed domain). A finite element method was employed to discretize the mathematical model and a finite difference approach was applied to the Stefan problem to determine the free interface. In this study, an effective stroke is assumed to start when the cilia make a 140∘ angle to the horizontal plane and the velocitiesof cilia increase until the cilia are perpendicular to the horizontal plane. Then, the velocities of the cilia decrease until the cilia make a 40∘ angle with the horizontal plane. From the numerical results, we can see that although the velocities of the cilia increase and then decrease, the free interface at the tips of the cilia continues increasing for the full forward phase. The numerical results are verified and compared with an exact solution and experimental data from the literature. Regarding the fixed boundary, the numerical results converge to the exact solution. Regarding the free interface, the numerical solutions were compared with the average height of the PCL in non-cystic fibrosis (CF) human tissues and were in excellent agreement. This research also proposes possible values of parameters in the mathematical model in order to determine the free interface. Applications of these fluid flows include animal hair, fibers and filter pads, and rice fields.

AN EVALUATION OF SEVERAL METHODS OF ESTIMATING SITE INDEX OF IMMATURE STANDS

1952 ◽  
Vol 28 (3) ◽  
pp. 63-74 ◽  
Author(s):  
John W. Ker
Keyword(s):  
Basal Area ◽  
Site Index ◽  
Site Quality ◽  
Average Height ◽  
Office Procedure ◽  
Minimum Sample ◽  
A Site ◽  
The University ◽  
Site Classes

The use of dominant heights for the estimation of site index is compared with the use of the average of dominant and codominant heights. Data collected on the University Research Forest are presented to illustrate the variability in tree heights and diameters within the two upper crown classes in well-stocked stands of immature Douglas fir.HeightIt is shown that the use of dominant heights reduces considerably the number of measurements required for a site index determination of given accuracy. Minimum sample sizes are given for three limits of accuracy for use in different site qualities. A general field and office procedure is outlined for the determination of minimum sample size in stands other than those described.DiameterThe use of diameter in site determination is discussed. Site indices based on the height of the tree of mean diameter, the height of the tree of mean basal area, and mean height are compared.ConclusionsQuick estimates of site quality can best be obtained by the measurement of total height of sample dominant trees, selected at random. For this purpose, tables are presented which list the average height of dominant trees by age and site classes for use in stands of Douglas fir, and western hemlock, respectively.

Consideration of Existing Anthropometric Data in Industrial Workplace Layout Design

1980 ◽  
Vol 24 (1) ◽  
pp. 27-30 ◽  
Author(s):  
Biman Das ◽  
Robert M. Grady
Keyword(s):  
Horizontal Plane ◽  
Layout Design ◽  
Reference Points ◽  
Anthropometric Data ◽  
Male And Female ◽  
Individual Male ◽  
Industrial Operations

Industrial workplace layout design dimensions were determined, through the use of the existing anthropometric data, for performing industrial tasks in sitting, standing and combination of both sitting and standing positions for general male, female and combination of both male and female operators and individual male and female operators for the 5th, 50th and 95th percentiles (only the workplace layout design dimensions for the seated operator are presented in this paper). The normal and maximum reach dimensions were based on the most commonly used industrial operations, which require a grasping movement. However, appropriate allowances were provided to adjust the reach dimensions for other types of industrial operations. To facilitate the design of industrial workplace layout, the normal and maximum horizontal and vertical clearance dimensions and reference points for the horizontal and vertical clearances were established. Squires' concept for the determination of normal working area in the horizontal plane was recommended in preference to Farley's.

THE POLARIZATION CHARACTERISTICS OF Pi-2 MICROPULSATIONS AND THEIR RELATION TO THE DETERMINATION OF POSSIBLE SOURCE MECHANISMS FOR THE PRODUCTION OF NIGHTTIME IMPULSIVE MICROPULSATION ACTIVITY

1967 ◽  
Vol 45 (3) ◽  
pp. 1319-1335 ◽  
Author(s):  
Gordon Rostoker
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Horizontal Plane ◽  
Auroral Zone ◽  
Propagation Path ◽  
Source Mechanisms ◽  
Polarization Characteristics ◽  
Direction Of Polarization

From the analysis of 20 separate events it is shown that Pi-2 micropulsations are polarized in an anticlockwise sense in the horizontal plane at northern-hemisphere mid-latitude stations. Combined with the knowledge that in the southern hemisphere polarization is predominantly in the clockwise sense, it can be inferred that at least the last part of the propagation path of the Pi 2 from the auroral zone to the observing station is traversed in the Alfvén mode. The presence of occasional pulsations possessing clockwise polarization in the northern hemisphere and anticlockwise polarization in the southern hemisphere suggests that the Alfvén mode alone is insufficient to explain the mode of propagation of a Pi 2. It is shown how ionospheric screening may influence the direction of polarization of a micropulsation. It is found that the initial kick of a Pi-2 micropulsation is strongly related to the sign of the accompanying geomagnetic bay. Deviations from this trend are discussed and it is shown that the Pi-2 micropulsation train and the initial kick may be considered as two separate effects. A theory for the origin of Pi-2 micropulsations is proposed.

DETERMINATION AND SIGNIFICANCE OF A DIETARY ALLOWANCE OF PROTEIN FOR INFANTS

PEDIATRICS ◽  
1959 ◽  
Vol 23 (2) ◽  
pp. 384-399
Author(s):  
Charles D. May
Keyword(s):  
National Research Council ◽  
Artificial Feeding ◽  
Cow’S Milk ◽  
Market Place ◽  
Cow's Milk ◽  
Dietary Allowance ◽  
Food And Nutrition ◽  
Selection Of

PROBABLY the greatest contributions to successful artificial feeding of infants that will ever be witnessed have already been made, namely: the discovery of the importance of bacterial contamination; the recognition of the role of vitamins; and the realization that fresh cow's milk produces large curds in the infant's stomach and must be treated by heat or other means to improve its digestibility. Elimination of these major handicaps of artificial feeding permitted attention to be focused on determination of precise figures for the amounts of individual nutrients which should be supplied by the diet to foster sound nutrition. Especial interest was attracted by the question of the relative adequacy of the protein in cow's milk and human milk. This called for refinement in methods of appraising the state of nutrition and clarification of the ultimate goal in infant feeding—the most desirable state of nutrition. Premature or excessive emphasis on selection of a figure for the dietary allowance of a nutrient is liable to arouse emotional controversy and distract nutritionists from the fundamental issues involved in judging nutritional status. Progress in the science of nutrition could easily be hampered by satisfaction with the sort of pseudosophistication so readily conveyed by plain numbers. If a figure for an allowance is proposed, there is a great temptation to exploit such a handy value by matching the composition of food products against this kind of "standard." The clamor of conflicting claims in the market place threatens to obscure the deficiencies in the fundamental knowledge upon which a meaningful figure for the allowance of protein or any other nutrient must be based. The Food and Nutrition Board of the National Research Council has now wisely recognized these considerations by not including a figure for protein allowance in infancy in the 1958 revision of their Recommended Dietary Allowances which states: "Breast-feeding is the best and desired procedure for meeting the nutrient requirements in the first months of life." This is a favorable setting in which to survey the principles which should govern the determination of the dietary allowance of protein for infants and to dwell upon the significance to be attached to any value proposed.

scholarly journals Drifting-snow acoustic detector: experimental tests in La Molina, Spanish Pyrenees

1998 ◽  
Vol 26 ◽  
pp. 221-224 ◽  
Author(s):  
D. Font ◽  
F. Naaim-Bouvet ◽  
M. Roussel
Keyword(s):  
Experimental Tests ◽  
Electrical Signal ◽  
Average Height ◽  
Acoustic Detector ◽  
Drifting Snow ◽  
Spanish Pyrenees ◽  
Wind Velocities ◽  
Drift Density ◽  
Exact Amount

A new gauge to detect drifting snow has been tested at an experimental site at La Molina, eastern Spanish Pyrenees during the 1996 winter.Based on an acoustic principle, it consiste of a miniature microphone located at the base of an aluminium pole of a Variable length (depending on the average height of the snow accumulated in a season). While snowdrifting occurs and the pole is exposed to the flux (wind + snow particles), the snow grains impact on the pole and the sound produced by these collisions is recorded as an electrical signal.30 m away from the snowdrifting detector, there is an anemometric station. The comparison of both records allows determination of thresholds and deposit wind velocities. In addition, this gauge allows users to know, during a wind episode, the exact amount of time during which snowdrifting occurs without being in the field. The interpretation of the values obtained using the acoustic detector is not yet an easy subject to discuss. We slill do not know what the drift-density equivalents for tile recorded noise levels are. However, these are only preliminary results and we expect to complete the calibration of the gauge during the coming months.

Sign in / Sign up

Export Citation Format

Share Document