The angle of reach as a mobility index for small and large landslides

1996 ◽  
Vol 33 (2) ◽  
pp. 260-271 ◽  
Author(s):  
Jordi Corominas
Keyword(s):  
Scale Effects ◽  
Regression Equations ◽  
Relative Mobility ◽  
Mass Wasting ◽  
Volume Increase ◽  
Runout Distance ◽  
Landslide Mass ◽  
Height Of Fall ◽  
Reach Angle ◽  
Topographic Constraints

The relations between the angle of reach (fahrböschung) and other indexes expressing the mobility of landslides and vertical drop, horizontal reach, and volume of landslide mass have been analyzed by means of simplified plots and regression equations. Results for 204 landslides of all sizes show that whatever the mechanism of motion, all kinds of landslides experience a continuous reduction of the angle of reach with volume increase. This reduction starts from the smallest sizes. Scattering in this relation is mostly due to mechanisms of motion and to both obstacles and topographic constraints on the path. This synthesis indicates that small landslides (less than 0.5 × 106 m3), in relative terms, display excesses of travel distance similar to large landslides. Since most small landslides are not expected to develop any change in the mechanism of progression while moving, the decrease in the reach angle with volume suggests that scale effects should be taken into account. The angle of reach is found to be a proper indicator of the relative mobility of landslides and is not dependent on the height of fall. Key words: mass wasting, landslides, reach angle, runout distance, rock avalanches, shallow landslides.

Momentum transfer and friction in the debris of rock avalanches

1989 ◽  
Vol 26 (4) ◽  
pp. 623-628 ◽  
Author(s):  
W. Van Gassen ◽  
D. M. Cruden
Keyword(s):  
Momentum Transfer ◽  
Sliding Friction ◽  
Rock Avalanche ◽  
Initial Position ◽  
Mass Wasting ◽  
Accurate Calculation ◽  
Frictional Material ◽  
Runout Distance ◽  
Debris Accumulation ◽  
Centre Of Gravity

When a mass of loose, dry, purely frictional material slides down an incline after release at a given velocity, the runout (the distance the centre of gravity of the displaced mass moves from its initial position) depends on momentum transfer within the mass. This can be estimated from the profile of the debris accumulation, which also allows more accurate calculation of apparent angles of sliding friction in rockfall avalanches. The apparent extreme mobility of the Elm and Frank slides, typical rockfall avalanches, is explained by momentum transfer in a loose, dry, purely frictional material with an angle of friction of 30°. Key words: mass wasting, momentum transfer, landslide, accumulation, rock avalanche, runout distance.

Microstructural and Microchemical Characterization of Nickel Sulfide Inclusions in Plate Glass

1991 ◽  
Vol 49 ◽  
pp. 962-963
Author(s):  
J. Cooper ◽  
O. Popoola ◽  
W. M. Kriven
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Glass Matrix ◽  
Nickel Sulfide ◽  
Plate Glass ◽  
Thermal Expansion Mismatch ◽  
Volume Increase ◽  
Β Phase ◽  
Microchemical Characterization

Nickel sulfide inclusions have been implicated in the spontaneous fracture of large windows of tempered plate glass. Two alternative explanations for the fracture-initiating behaviour of these inclusions have been proposed: (1) the volume increase which accompanies the α to β phase transformation in stoichiometric NiS, and (2) the thermal expansion mismatch between the nickel sulfide phases and the glass matrix. The microstructure and microchemistry of the small inclusions (80 to 250 μm spheres), needed to determine the cause of fracture, have not been well characterized hitherto. The aim of this communication is to report a detailed TEM and EDS study of the inclusions.

Strain analysis in composite ceramics

1986 ◽  
Vol 44 ◽  
pp. 494-497
Author(s):  
W. M. Kriven
Keyword(s):  
Strain Field ◽  
Strain Analysis ◽  
Processing Temperature ◽  
Transformation Toughening ◽  
Zirconia Ceramics ◽  
Volume Increase ◽  
Analysis Technique ◽  
Fundamental Understanding ◽  
Contrast Analysis ◽  
Elastic Strain Field

Significant progress towards a fundamental understanding of transformation toughening in composite zirconia ceramics was made possible by the application of a TEM contrast analysis technique for imaging elastic strains. Spherical zirconia particles dispersed in a large-grained alumina matrix were examined by 1 MeV HVEM to simulate bulk conditions. A thermal contraction mismatch arose on cooling from the processing temperature of 1500°C to RT. Tetragonal ZrO2 contracted amisotropically with α(ct) = 16 X 10-6/°C and α(at) = 11 X 10-6/°C and faster than Al2O3 which contracted relatively isotropically at α = 8 X 10-6/°C. A volume increase of +4.9% accompanied the transformation to monoclinic symmetry at room temperature. The elastic strain field surrounding a particle before transformation was 3-dimensionally correlated with the internal crystallographic orientation of the particle and with the strain field after transformation. The aim of this paper is to theoretically and experimentally describe this technique using the ZrO2 as an example and thereby to illustrate the experimental requirements Tor such an analysis in other systems.

Synovial Volume Increase May Flag Worsening OA

2008 ◽  
Vol 7 (2) ◽  
pp. 7
Author(s):  
DAMIAN MCNAMARA
Keyword(s):  
Volume Increase

Length scale effects on the macroscopic behaviour of single and polycrystalline FCC crystals

2001 ◽  
Vol 11 (PR5) ◽  
pp. Pr5-161-Pr5-170 ◽  
Author(s):  
E. P. Busso ◽  
K. S. Cheong
Keyword(s):  
Scale Effects ◽  
Length Scale

Computer Assistance in the Clinical Investigation of Pulmonary Function Studies

1973 ◽  
Vol 12 (02) ◽  
pp. 102-107 ◽  
Author(s):  
D. J. Protti ◽  
Nancy Craven ◽  
A. Naimark ◽  
R. M. Cherniack
Keyword(s):  
Information System ◽  
Pulmonary Function ◽  
Additional Data ◽  
Normal Values ◽  
Clinical Investigation ◽  
Regression Equations ◽  
Beneficial Effects ◽  
Computer Assistance ◽  
Manual Methods

A previously described comprehensive respiratory information system (CRIS) has been changed to introduce new spirometric tests which are sensitive to minor abnormalities, revise on the basis of additional data the regression equations which define normal values to various parameters of pulmonary function and refine the system’s interpretation scheme. The beneficial effects of transferring the system from a large IBM 360/65 to a small CDC 1700 are presented. An analysis of the costs of processing routine pulmonary function studies reveals that a 40°/o saving is realized when a computer is used in comparison to the use of the usual manual methods.

Studying the factors of regional insurance market development using the correlation and regression analysis

2020 ◽  
Vol 26 (7) ◽  
pp. 1610-1630
Author(s):  
E.L. Prokop'eva
Keyword(s):  
Regression Analysis ◽  
Federal District ◽  
Insurance Market ◽  
Market Development ◽  
Insurance Markets ◽  
Regression Equations ◽  
Factors Affecting ◽  
Correlation And Regression Analysis ◽  
Country Level ◽  
Inverse Effect

Subject. The article investigates and quantifies factors of insurance markets functioning in Russian regions, and reveals possibilities to manage them. Objectives. The purpose of the study is to substantiate regional factors that determine the specifics of regional insurance market development; to quantify them to increase the efficiency of regional insurance. Methods. The study draws on statistical methods, functional analysis, algorithm development, correlation and regression analysis. Results. I calculated coefficients of pair and multiple correlation with the indicators of insurance markets in the context of the subjects of the Russian Federation, and composed regression equations. Based on the analysis, I determined the algorithm for inverse effect of the insurance market on the economic, social, fiscal and environmental performance of the region, offered appropriate measures aimed at developing the economic potential of the region and its social sphere. Conclusions. The paper considers the case of the Republic of Khakassia, one of depressed subjects in the Siberian Federal District. The developed models can be used for other regions of Russia, given the geographical and economic features of development. The findings may help generate regional strategies for socio-economic development at the country level. The scientific contribution and the novelty of the work consist of systematizing and quantifying the factors affecting the insurance mechanisms of regional markets, and assessing the inverse effect of insurance mechanisms on integrated development of the region.

Scale Effects in Laboratory and Pilot-Plant Reactors for Trickle-Flow Processes

1991 ◽  
Vol 46 (4) ◽  
pp. 501-515 ◽  
Author(s):  
S. T. Sie
Keyword(s):  
Pilot Plant ◽  
Scale Effects ◽  
Flow Processes

Determination of the metal toughness components in impact-bending test

2018 ◽  
Vol 84 (12) ◽  
pp. 68-72
Author(s):  
A. B. Maksimov ◽  
I. P. Shevchenko ◽  
I. S. Erokhina
Keyword(s):  
Crack Growth ◽  
Specific Energy ◽  
Crack Formation ◽  
Crack Nucleation ◽  
Scale Effects ◽  
Linear Equations ◽  
Bending Test ◽  
Cross Sectional ◽  
Two Samples ◽  
Sample Width

A method for separating the work of impact into two parts - the work of the crack nucleation and that of crack growth - which consists in testing two samples with the same stress concentrators and different cross-sectional dimensions at the notch site is developed. It is assumed that the work of crack nucleation is proportional to the width of the sample face on which the crack originates and the specific energy of crack formation, whereas the work of the crack growth is proportional to the length of crack development and the specific crack growth energy. In case of the sample fracture upon testing, the crack growth length is assumed equal to the sample width. Data on the work of fracture of two samples and their geometrical dimensions at the site of the notch are used to form a system of two linear equations in two unknowns, i.e., the specific energy of crack formation and specific energy of crack growth. The determined specific energy values are then used to calculate the work of crack nucleation and work of crack growth. The use of the analytical method improves the accuracy compared to graphical - extrapolative procedures. The novelty of the method consists in using one and the same form of the notch in test samples, thus providing the same conditions of the stress-strain state for crack nucleation and growth. Moreover, specimens with different cross-section dimensions are used to eliminate the scale effects. Since the specific energy of the crack nu-cleation and specific energy of the crack growth are independent of the scale factor, they are determined only by the properties of the metal. Introduction the specific energy of crack formation and growth makes possible to assign a specific physical meaning to the fracture energy.

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