A Note on Friction Ratio

1975 ◽  
Vol 12 (4) ◽  
pp. 524-526
Author(s):  
Umesh Dayal ◽  
J. H. Allen
Keyword(s):  
Constant Velocity ◽  
Maximum Velocity ◽  
Granular Soils ◽  
Cohesive Soils ◽  
Moisture Contents ◽  
Different Types ◽  
Side Friction ◽  
Penetration Tests ◽  
Local Side ◽  
Penetration Velocity

Constant velocity penetration tests were conducted on the different types of soils ranging from gravelly sand through clay of various strengths and moisture contents. The tests were performed for various penetration velocities up to a maximum of 2.66 f.p.s. (81.14 cm/s). From the measured cone pressure and local side friction (sleeve friction), the friction ratio is calculated at various penetration velocities. The experimental results indicate that for granular soils the influence of penetration velocity on friction ratio is insignificant. In cohesive soils the increase in penetration velocity causes an increase in friction ratio which amounted to 80% at the maximum velocity used.

The Effect of Penetration Rate on the Strength of Remolded Clay and Sand Samples

1975 ◽  
Vol 12 (3) ◽  
pp. 336-348 ◽  
Author(s):  
Umesh Dayal ◽  
John H. Allen
Keyword(s):  
Penetration Rate ◽  
Velocity Ratio ◽  
Viscosity Coefficient ◽  
Analytical Relationship ◽  
Granular Soils ◽  
Cohesive Soils ◽  
Static Tests ◽  
Proportionality Constant ◽  
Penetration Tests ◽  
Penetration Velocity

The penetration rate effect on the strength of clay and sand was studied by constant velocity penetration tests performed with various velocities up to 2.662 f.p.s. (81.14 cm/s). The clay and sand targets were of various strengths and moisture contents. The construction of the penetrometer is similar to that used in static tests, and in each test the cone resistance, sleeve friction, and penetration velocity were recorded.Experimental results indicated that for granular soils the effects of penetration velocity on cone and sleeve friction resistances are insignificant, whereas, for cohesive soils, the increase in penetration velocity causes an increase in the cone and friction resistances. It is found that for the cohesive soils the ratio of dynamic to static strength is directly proportional to the logarithm of the penetration velocity ratio. The proportionality constant of this relationship defined as soil viscosity coefficient depends on the physical properties of the soil and the soil strength and its value increases as the strength of the soil decreases. For the tested soils various values of the soil viscosity coefficient are proposed for different strength ranges. The validity of the analytical relationship is established for penetration velocities ranging from 0.0044 f.p.s. (0.13 cm/s) to 18 f.p.s. (550 cm/s).

Bose-Einstein-type statistics, order statistics and planar random motions with three directions

2004 ◽  
Vol 36 (3) ◽  
pp. 937-970 ◽  
Author(s):  
S. Leorato ◽  
E. Orsingher
Keyword(s):  
Partial Differential Equations ◽  
Order Statistics ◽  
Constant Velocity ◽  
Uniform Motion ◽  
Change Of Direction ◽  
Telegraph Process ◽  
Cyclic Motion ◽  
Different Types ◽  
Random Motions ◽  
Bose Einstein

In this paper we study different types of planar random motions (performed with constant velocity) with three directions, defined by the vectors dj = (cos(2πj/3), sin(2πj/3)) for j = 0, 1, 2, changing at Poisson-paced times. We examine the cyclic motion (where the change of direction is deterministic), the completely uniform motion (where at each Poisson event each direction can be taken with probability ) and the symmetrically deviating case (where the particle can choose all directions except that taken before the Poisson event). For each of the above random motions we derive the explicit distribution of the position of the particle, by using an approach based on order statistics. We prove that the densities obtained are solutions of the partial differential equations governing the processes. We are also able to give the explicit distributions on the boundary and, for the case of the symmetrically deviating motion, we can write it as the distribution of a telegraph process. For the symmetrically deviating motion we use a generalization of the Bose-Einstein statistics in order to determine the distribution of the triple (N0, N1, N2) (conditional on N(t) = k, with N0 + N1 + N2 = N(t) + 1, where N(t) is the number of Poisson events in [0, t]), where Nj denotes the number of times the direction dj (j = 0, 1, 2) is taken. Possible extensions to four directions or more are briefly considered.

Contribution of Composition, Physicochemical Characteristics and Polyphosphates to the Microbial Safety of Pasteurized Cheese Spreads

1994 ◽  
Vol 57 (4) ◽  
pp. 295-300 ◽  
Author(s):  
KARL F. ECKNER ◽  
WENDY A. DUSTMAN ◽  
ANNA A. RYŚ-RODRIGUEZ
Keyword(s):  
Clostridium Botulinum ◽  
Toxin Production ◽  
Physicochemical Characteristics ◽  
The Other ◽  
Microbial Safety ◽  
Processed Cheese ◽  
Moisture Contents ◽  
Glass Containers ◽  
Different Types ◽  
Process Cheese

Pasteurized process cheese spread was manufactured with moisture contents of 52, 54, 56 and 60%. Three different types of phosphate emulsifier were used, disodium ortho-phosphate and two commercially-available polyphosphates, S9 and S9H. Pasteurized, processed cheese spreads were inoculated with approximately 1 × 104 Clostridium botulinum spores/gram cheese in the cook kettle, held 3 min at 80°C, hot-filled into glass containers, and incubated at 30°C. Samples were analyzed over 30 weeks for growth of C. botulinum and toxigenesis. Toxin was first detected in 60% moisture cheese with disodium ortho-phosphate as the emulsifier at 8 weeks and in 60% moisture cheese with the test polyphosphates as the emulsifier when tested at 20 weeks. None of the other cheese formulations were toxic at 20 weeks. Toxin production correlated statistically to time, moisture, pH and phosphate type.

Bose-Einstein-type statistics, order statistics and planar random motions with three directions

2004 ◽  
Vol 36 (03) ◽  
pp. 937-970 ◽  
Author(s):  
S. Leorato ◽  
E. Orsingher
Keyword(s):  
Partial Differential Equations ◽  
Order Statistics ◽  
Constant Velocity ◽  
Uniform Motion ◽  
Change Of Direction ◽  
Telegraph Process ◽  
Cyclic Motion ◽  
Different Types ◽  
Random Motions ◽  
Bose Einstein

In this paper we study different types of planar random motions (performed with constant velocity) with three directions, defined by the vectorsdj= (cos(2πj/3), sin(2πj/3)) forj= 0, 1, 2, changing at Poisson-paced times. We examine the cyclic motion (where the change of direction is deterministic), the completely uniform motion (where at each Poisson event each direction can be taken with probability) and the symmetrically deviating case (where the particle can choose all directions except that taken before the Poisson event). For each of the above random motions we derive the explicit distribution of the position of the particle, by using an approach based on order statistics. We prove that the densities obtained are solutions of the partial differential equations governing the processes. We are also able to give the explicit distributions on the boundary and, for the case of the symmetrically deviating motion, we can write it as the distribution of a telegraph process. For the symmetrically deviating motion we use a generalization of the Bose-Einstein statistics in order to determine the distribution of the triple (N0,N1,N2) (conditional onN(t) =k, withN0+N1+N2=N(t) + 1, whereN(t) is the number of Poisson events in [0,t]), whereNjdenotes the number of times the directiondj(j= 0, 1, 2) is taken. Possible extensions to four directions or more are briefly considered.

scholarly journals Grain-scale DEM study of open-ended pipe pile penetration in granular soils

2021 ◽  
Vol 249 ◽  
pp. 11007
Author(s):  
Michail Komodromos ◽  
Gaël Combe ◽  
Gioacchino Viggiani
Keyword(s):  
Distinct Element ◽  
Horizontal Stress ◽  
Granular Soils ◽  
Pipe Pile ◽  
Pile Shaft ◽  
Offshore Engineering ◽  
Pile Penetration ◽  
Penetration Tests ◽  
Shed Light ◽  
Number Of Particles

Open-Ended Pipe Piles (OEPP) are particularly popular in offshore engineering. An important feature of the installation of these piles is the rate with which soil enters the pile from the bottom, and its interaction with the internal pile shaft. The response of OEPP crucially depends on the occurrence of soil plugging, which can make the behavior of an OEPP similar to a pile of solid cross section. Plugging is generally attributed to arching effects in the soil; therefore, understanding this phenomenon requires an investigation at the grain scale. This is precisely the objective of this study, where the Distinct Element Method (DEM) is used to study the installation of an Open-Ended Pipe Pile in a Virtual Calibration Chamber comprising 128000 grains, under constant horizontal stress. Despite the relatively small number of particles, this numerical model is found to be able to reproduce several aspects of the mechanisms actually observed in thefield. The results are compared to those obtained from actual experiments of miniature pile penetration tests. Stress and strainfields that develop in the soil inside and outside the pile provide interesting data and shed light on the mechanisms at play during OEPP installation, especially as for the influence of grains interlocking.

scholarly journals PHYSICO-CHEMICAL STANDARDIZATION OF A UNANI ANALGESIC FORMULATION HABB-E-SURANJAN

2019 ◽  
Vol 9 (4-A) ◽  
pp. 486-489
Author(s):  
Shahid Suhail ◽  
Shagufta Parveen ◽  
Shazia Jilani ◽  
, Shama
Keyword(s):  
Moisture Content ◽  
Petroleum Ether ◽  
Fluorescence Analysis ◽  
Normal Range ◽  
Moisture Contents ◽  
Loss Of Weight ◽  
Physico Chemical ◽  
Different Types ◽  
Microscopic Features ◽  
Effective Role

Habb-e-Suranjaan is an important compound preparation which is used for a centuries in Unani system of medicine as an effective analgesic for all types of Waj-al-Mafasil (Arthritics). The drug is known for its pharmacological actions such as Mushile-Balgham (Phlegmagogue), Mushile-Safra (Cholagogue), Mushile-Sauda (Melanagogue), Mohallile-Waram (Anti-inflammatory), Musakkin-e-Alam (Analgesic), Dafae Niqris (Anti-gout) Muqawwi-e asaab (Nervine tonic) Munawwim (Hypnotic/Soporific), Musaffi-e-Dam (Blood Purifier). Ingredients of Habb-e-Suranjaan play very effective role in management of different types of Waj-al-Mafasil.  In this article, standardized value of a specimen of Habb-e Suranjaan assessed on physico-chemical and analytical parameters viz Macroscopic and microscopic features, extractive values, moisture contents, Ash values, loss of weight on drying, pH of 1 % and 10 % solution, TLC and  Fluorescence analysis are provided. The moisture content and the ash value were found within the recommended normal range. The value of different hot extracts (Petroleum ether, Methanol, chloroform and Aqueous) is more than the cold extracts of drug. Keywords-  Habb-e-Suranjaan, Waj-al-Mafasil, Analgesic.

scholarly journals Proposta de previsão da capacidade de carga à tração de estacas tipo hélice contínua em solos granulares

2020 ◽  
Vol 1 (48) ◽  
pp. 146
Author(s):  
Caio Cardoso Scipião ◽  
Alfran Sampaio Moura
Keyword(s):  
Bearing Capacity ◽  
Granular Soils ◽  
Specific Method ◽  
Uplift Capacity ◽  
Security Measures ◽  
Structural Element ◽  
Compressive Loads ◽  
Penetration Tests ◽  
Uplift Forces

Foundations projects must present security measures concerning the structural element and soil-structure system failure and acceptable displacements. In buildings it is very common to have foundations which are only subjected to compressive loads, however, in many of them, the foundations are submitted to uplifting forces, thus it is also necessary to verify the safety conditions regarding uplift capacity. In this context, this article evaluates the applicability of specific and non-specific methods for estimating the uplift bearing capacity of continuous flight auger piles in granular soils. In addition to that, a method was developed in order to estimate the ultimate uplift capacity of these pile types. In order to so, this research was based on 97 Standard Penetration Tests (SPT), and 12 continuous flight auger piles in granular soils subjected to the uplift forces. Among the evaluated literature methods, the specific method that presented the best agreement was Meyerhof and Adams (1968), and the non-specific one was Meyerhof (1953), both with approximately 65% higher values, in average, than the reference values and with great scatter. On the other hand, the developed method presented good agreement and lower scatter, establishing an alternative for the determination of uplift bearing capacity of continuous flight auger piles in granular soils.

scholarly journals Discrete modeling of penetration tests in constant velocity and impact conditions

2016 ◽  
Vol 71 ◽  
pp. 12-18 ◽  
Author(s):  
Quoc Anh Tran ◽  
Bastien Chevalier ◽  
Pierre Breul
Keyword(s):  
Constant Velocity ◽  
Discrete Modeling ◽  
Penetration Tests

Analysis of Wood Combustion Based on the First and Second Laws of Thermodynamics

1987 ◽  
Vol 109 (3) ◽  
pp. 129-141 ◽  
Author(s):  
A. Dadkhah-Nikoo ◽  
D. J. Bushnell
Keyword(s):  
Moisture Content ◽  
Energy Content ◽  
Wood Combustion ◽  
Moisture Contents ◽  
Direct Combustion ◽  
Air Temperatures ◽  
Wide Range ◽  
Laws Of Thermodynamics ◽  
Different Types ◽  
Wood Fuels

Wood is a highly flexible fuel which can be used in a variety of ways for energy generation. Direct combustion of wood is the oldest method of utilization of this renewable energy source. This paper presents an analysis of wood combustion based on the first and second laws of thermodynamics, using a computer program developed for this study. Since the moisture content of the available wood fuels vary over a wide range, special attention is given to the effects of moisture content on the exergy and energy content of the wood. Because of the wide variation in particle size and moisture content of the wood fuels, different types of combustion systems have been designed and are utilized in industry. Each combustion system uses a certain amount of combustion air and is designed for a certain range of combustion air temperatures and wood fuel moisture contents. The effects of these variables on wood combustion and the efficiencies of the process have been studied and are presented in this paper. To point out the importance and differences between efficiencies that are commonly used, several efficiencies based on the first and the second laws of the thermodynamics are calculated and compared. Based on the results presented in this report, it is concluded that, over the range of variables studied, the most efficient conditions for wood combustion can be achieved by using the minimum amount of excess air at highest permissible temperature. It is also concluded that the lower moisture contents result in higher combustion efficiencies.

Sign in / Sign up

Export Citation Format

Share Document