A Regional Study of Landsliding Near Ottawa

1971 ◽  
Vol 8 (2) ◽  
pp. 315-335 ◽  
Author(s):  
D. A. Sangrey ◽  
M. J. Paul
Keyword(s):  
Soil Characteristics ◽  
Aerial Photographs ◽  
Test Results ◽  
Regional Study ◽  
Field Situation ◽  
Flow Slides ◽  
The Stability ◽  
Clay Layers ◽  
Strength Relationship ◽  
Natural Slopes

The stability of natural slopes near Ottawa has been examined from a regional approach. With the aid of aerial photographs, the density and distribution of past landslides have been ascertained, and the development of more recent slides has been traced. This information, combined with details of the present day topography, groundwater conditions, and soil characteristics, leads to a conclusion that factors influencing slope stability vary markedly throughout the region, and certain areas are much more prone to sliding than others.The strength of soils in the region is discussed, including the development of a logical shear strength relationship which incorporates the effects both of cementation strength and fissuring. The influence of sample size on the extrapolation of laboratory triaxial test results to the field situation is introduced. Details of the method of landslide analysis used are given.Considerable evidence is presented to support the presence of separate marine and freshwater clay layers in the Ottawa area, and to suggest that flow slides are confined to the upper freshwater deposit. These two clay soils are most graphically distinguished by differences in fissure spacing and pore water chemistry.

scholarly journals Effect of Strength Anisotropy on the Stability of Natural Slopes

2021 ◽  
Vol 710 (1) ◽  
pp. 012025
Author(s):  
Magnus T Aamodt ◽  
Gustav Grimstad ◽  
Steinar Nordal
Keyword(s):  
Strength Anisotropy ◽  
The Stability ◽  
Natural Slopes

scholarly journals Analytical and Experimental Investigation of the Stability of the Rotor-Bearing System of a New Small Turbocharger

1987 ◽  
Author(s):  
H. R. Born
Keyword(s):  
Experimental Investigation ◽  
Dynamic Stability ◽  
Squeeze Film ◽  
Test Results ◽  
Flow Capacity ◽  
Squeeze Film Dampers ◽  
Rotor Bearing ◽  
The Stability ◽  
Turbine Design ◽  
Bearing System

This paper presents an overview of the development of a reliable bearing system for a new line of small turbochargers where the bearing system has to be compatible with a new compressor and turbine design. The first part demonstrates how the increased weight of the turbine, due to a 40 % increase in flow capacity, influences the dynamic stability of the rotor-bearing system. The second part shows how stability can be improved by optimizing important floating ring parameters and by applying different bearing designs, such as profiled bore bearings supported on squeeze film dampers. Test results and stability analyses are included as well as the criteria which led to the decision to choose a squeeze film backed symmetrical 3-lobe bearing for this new turbocharger design.

Durability of BFRP and Hybrid FRP Sheets under Freeze-Thaw Cycling

2010 ◽  
Vol 163-167 ◽  
pp. 3297-3300 ◽  
Author(s):  
Jia Wei Shi ◽  
Hong Zhu ◽  
Zhi Shen Wu ◽  
Gang Wu
Keyword(s):  
Mechanical Properties ◽  
Test Data ◽  
Mechanical Characteristics ◽  
Test Results ◽  
Freeze Thaw ◽  
Frp Composites ◽  
Test Parameters ◽  
The Stability ◽  
Better Than

Coupon tests were conducted to investigate the mechanical characteristics of basalt FRP (BFRP) sheet, basalt-carbon hybrid FRP sheets and the corresponding epoxy rein under the effect of freeze-thaw cycling. FRP sheets and epoxy rein coupons were subjected to up to 200 and 250 freeze-thaw cycles respectively. Test parameters included the number of freeze-thaw cycles and the types of FRP composites. Test results show that (1) BFRP sheet perform better than CFRP or GFRP sheets under high freeze-thaw cycles; (2) exposed hybrid FRP sheets not only show very little loss in mechanical properties, but also contribute to the stability of test data; (3) mechanical properties of rein epoxy decrease significantly with increasing freeze-thaw cycles.

scholarly journals Analysis and Calculation of Stability Coefficients of Cross-Laminated Timber Axial Compression Member

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4267
Author(s):  
Qi Ye ◽  
Yingchun Gong ◽  
Haiqing Ren ◽  
Cheng Guan ◽  
Guofang Wu ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Axial Compression ◽  
Calculation Method ◽  
National Standards ◽  
Test Results ◽  
Average Deviation ◽  
Stability Coefficient ◽  
Cross Laminated Timber ◽  
Stability Bearing Capacity ◽  
The Stability

Cross-laminated timber (CLT) elements are becoming increasingly popular in multi-storey timber-based structures, which have long been built in many different countries. Various challenges are connected with constructions of this type. One such challenge is that of stabilizing the structure against vertical loads. However, the calculations of the stability bearing capacity of the CLT members in axial compression in the structural design remains unsolved in China. This study aims to determine the stability bearing capacity of the CLT members in axial compression and to propose the calculation method of the stability coefficient. First, the stability coefficient calculation theories in different national standards were analyzed, and then the stability bearing capacity of CLT elements with four slenderness ratios was investigated. Finally, based on the stability coefficient calculation formulae in the GB 50005-2017 standard and the regression method, the calculation method of the stability coefficient for CLT elements was proposed, and the values of the material parameters were determined. The result shows that the average deviation between fitting curve and calculated results of European and American standard is 5.43% and 3.73%, respectively, and the average deviation between the fitting curve and the actual test results was 8.15%. The stability coefficients calculation formulae could be used to predict the stability coefficients of CLT specimens with different slenderness ratios well.

scholarly journals Stability and Emission Characteristics of Diesel-Ethanol-Coconut Methyl Ester Blends for the Diesel Engines

2015 ◽  
Vol 14 (2) ◽  
pp. 1
Author(s):  
Tanti Ardiyati ◽  
Nathaniel P. Dugos ◽  
Susan A. Roces ◽  
Masaaki Suzuki ◽  
Kusnanto Kusnanto
Keyword(s):  
Methyl Ester ◽  
Diesel Engines ◽  
Emission Characteristics ◽  
Test Results ◽  
Fuel Blends ◽  
Fuel Consumption Rate ◽  
Efficient Combustion ◽  
Smoke Opacity ◽  
The Stability ◽  
Blended Fuels

The stability and emission characteristics of diesel-ethanol-coconut methyl ester (CME) blends were studied to determine the most suitable fuel blends to be applied in diesel engines. This is done in order to assess the potential of the blends as a substitute for commercially available diesel fuel used in diesel engine. The stability results of the blends using 100% and 99.5% ethanol purity showed that the fuel blends containing ethanol up to 10% and CME of 5% and greater exhibited high mutual solubility at any temperature range and were resistant to microbial growths after 3 months storage. Engine operations at low speed especially at idle-no load and using a bigger size engine lead to a minimum ignition delay and result in lower fuel consumption rate. The emission test results with the new- blended fuels showed a reduction in CO2 and increasing percentage by volume of CO2 compared to commercially available diesel. The blends could deliver an efficient combustion and could run efficiently since production of the CO2 gases is higher than that of CO. The blends of 80% diesel, 5% ethanol, 10% CME; and 80% diesel, 10% ethanol, 10% CME could reduce the smoke opacity compared to commercially available diesel.

scholarly journals Lyapunov Based Estimation of Flight Stability Boundary under Icing Conditions

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Binbin Pei ◽  
Haojun Xu ◽  
Yuan Xue
Keyword(s):  
Equilibrium Point ◽  
External Disturbance ◽  
Stability Boundary ◽  
Wind Tunnel Test ◽  
Test Results ◽  
Theoretical Support ◽  
Effect Model ◽  
Short Period ◽  
The Stability ◽  
Period Model

Current fight boundary of the envelope protection in icing conditions is usually defined by the critical values of state parameters; however, such method does not take the interrelationship of each parameter and the effect of the external disturbance into consideration. This paper proposes constructing the stability boundary of the aircraft in icing conditions through analyzing the region of attraction (ROA) around the equilibrium point. Nonlinear icing effect model is proposed according to existing wind tunnel test results. On this basis, the iced polynomial short period model can be deduced further to obtain the stability boundary under icing conditions using ROA analysis. Simulation results for a series of icing severity demonstrate that, regardless of the icing severity, the boundary of the calculated ROA can be treated as an estimation of the stability boundary around an equilibrium point. The proposed methodology is believed to be a promising way for ROA analysis and stability boundary construction of the aircraft in icing conditions, and it will provide theoretical support for multiple boundary protection of icing tolerant flight.

scholarly journals SYNTHESIS AND STABILITY OF RESVERATROL-CONJUGATED GOLD NANOPARTICLES MODIFIED WITH POLYETHYLENE GLYCOL

2020 ◽  
pp. 230-236
Author(s):  
RADITYA ISWANDANA ◽  
RICHA NURSELVIANA ◽  
SUTRIYO SUTRIYO
Keyword(s):  
Particle Size ◽  
Gold Nanoparticles ◽  
Polyethylene Glycol ◽  
Zeta Potential ◽  
High Performance ◽  
Entrapment Efficiency ◽  
Test Results ◽  
Novel Method ◽  
The Stability ◽  
Phosphate Buffered Saline

Objective: Gold nanoparticles (AuNPs) are highly useful for drug delivery, but their application is limited by their stability as they readily aggregate.This issue can be prevented by adding a stabilizing agent such as resveratrol (RSV), which is a polyphenol derived from plants, that is used to preventcancer. Therefore, we propose a novel method to prepare stable RSV-conjugated nanoparticles modified with polyethylene glycol (RSV-AuNP-PEG).Methods: In the first step, the Turkevich method was used to synthesize the AuNPs. Then, PEG was added as stabilizer agent and conjugated with RSV.The synthesized conjugates were characterized using ultraviolet-visible spectrophotometry, Fourier transform infrared spectroscopy, particle sizeanalysis, and high-performance liquid chromatography.Results: The obtained RSV-AuNP-PEG had a particle size of 83.93 nm with a polydispersity index (PDI) of 0.562 and formed a translucent purple-redfluid in solution. The zeta potential was −22.9 mV, and the highest entrapment efficiency was 75.86±0.66%. For comparison, the RSV-AuNP solutionwas purple and turbid, the particle size was 51.97 nm with a PDI of 0.694, and the zeta potential was −24.6 mV. The stability test results showed thatthe storage stability of RSV-AuNP-PEG was better than that of AuNP-RSV. Further, the RSV-AuNP-PEG was shown to be most stable in 2% bovine serumalbumin (BSA) while the AuNP-RSV was most stable in 2% BSA in phosphate-buffered saline pH 7.4.Conclusion: These results show that modification of RSV-conjugated AuNPs with PEG effectively prevents their aggregation in storage, but only incertain mediums.

Stability of Floating Body Using Moderate Lightweight Concrete Mixed with Crumb Rubber and Polymer

2015 ◽  
Vol 723 ◽  
pp. 431-434
Author(s):  
Werasak Raongjant ◽  
Meng Jing
Keyword(s):  
Test Data ◽  
Lightweight Concrete ◽  
Crumb Rubber ◽  
Floating Body ◽  
Test Results ◽  
Concrete Body ◽  
The Common ◽  
The Stability ◽  
Metacentric Height ◽  
Polymer Latex

The purposes of this research is to study the stability of floating body using moderate lightweight concrete of which the gross weight was modified by crumb rubber and polymer. The moderate lightweight concrete was prepared by replacing 10%, 20% or 30% of sand in weight with crumb rubber of size No.6 or No.26 and mixing with the fluid polymer latex in 7.5% or 15% of the weight of cement. The test results shown that the concrete 626CR10-7.5, replaced sand with 5% No.6 rubber and 5% No. 26 rubber and mixed with 7.5% polymer, had better permeable resistant. Six pieces of models in the shape of open box were produced using the common concrete and concrete 626CR10-7.5. The stability of floating concrete body was tested and the metacentric height and the period of roll were calculated based on the test data. It is concluded that the moderate lightweight concrete behaved better stability and was appropriate material for floating concrete structures.

Interpretation of the limits in shear strength in binary granular mixtures

2001 ◽  
Vol 38 (5) ◽  
pp. 1097-1104 ◽  
Author(s):  
Luis E Vallejo
Keyword(s):  
Shear Strength ◽  
Laboratory Tests ◽  
Relative Concentration ◽  
Frictional Resistance ◽  
Glass Beads ◽  
Rock Fragments ◽  
Structural Support ◽  
Granular Mixtures ◽  
The Stability ◽  
Natural Slopes

Many natural slopes and rockfill structures are made of a mixture of rock fragments and sand-size particles. To analyze the stability of such natural slopes and rockfills, a knowledge of how rock–sand mixtures develop their shear strength is needed. Laboratory tests conducted on mixtures of glass beads of two different sizes (5 and 0.4 mm) have indicated that their shear strength depends upon the relative concentration by weight of the large and small beads in the mixtures. If the concentration by weight of the large beads is greater than 70%, the shear strength of the mixtures is controlled by the frictional resistance of the large beads. If the concentration of the large beads is less than 40%, the shear strength of the mixtures is controlled by the frictional resistance of the small beads. If the concentration of the large beads is between 40 and 70%, the shear strength of the mixture is partially controlled by the frictional resistance provided by the large beads in the mixtures. These limits are very similar to those reported for rock–sand mixtures. To date, no explanation has been put forward to account for why these limits exist. This study presents an explanation for their existence. The explanation is based on the porosity developed by the mixtures and the type of structural support provided by the coarse and fine grains.Key words: shear strength, granular mixtures, porosity, fabric, compaction.

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