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Gases: comparison with experiment
Published in Michael de Podesta, Understanding the Properties of Matter, 2020
P6. Objects float if their average density is less than the density of the fluid in which they are immersed. A balloon of mass 10 g is made of a material with negligible wall thickness which does not stretch under pressure (a fair approximation for the plastic Mylar). It is filled with helium gas at 0°C and 1.1 × 105 Pa until it just floats in air at STP. (a) What is the volume of the balloon? (You should find that the volume of the balloon (expressed in m3) is very roughly the same as the total load on the balloon (expressed in kg), (b) What volume must the balloon have if it is to lift the weight of an adult human being, say 70 kg? (c) If the balloon just floats at STP, will it float or sink if the temperature is increased to room temperature? (Assume the volume of the balloon stays constant.)
Golf Course Construction and Renovation
Published in L.B. (Bert) McCarty, Golf Turf Management, 2018
Bulk density, defined as the mass (or weight) of dry soil per actual volume of the soil, is the more important parameter for golf course superintendents. Bulk density, unlike particle density, includes the pore space volume as well as the volume of soil solids. Since most soils are about half solids and half pore space, bulk densities tend to be about half the particle density. The higher the bulk density of a soil is, the greater is the compaction. The bulk density range for golf greens is between 1.25 and 1.55 g/cm3, with a lower limit of 1.20 g/cm3, an upper limit of 1.60 g/cm3, and an optimum level of 1.40 g/cm3. Incorporating organic matter, such as peat, is one means of reducing the bulk density of a golf green rootzone.
Properties of bulk materials
Published in D.V. Subba Rao, The Belt Conveyor, 2020
Bulk density of the material is an apparent density and is defined as the mass of the material divided by its total volume (particles and voids). Thus, bulk density,ρb=msolids+mvoidsVsolids+Vvoids
Analysis of wave-induced submarine landslides in nearly saturated sediments at intermediate water depths
Published in Marine Georesources & Geotechnology, 2022
Amin Rafiei, M. Shamimur Rahman, Mohammed A. Gabr, Majid Ghayoomi
Here, and indicate the components of normal effective stresses, is shear stress, and and are the components of displacement in horizontal and vertical directions of the soil skeleton, respectively. The total density of seabed sediment () is expressed as: in which and denote the density of soil solids and porosity. For isotropic linear elastic soil skeleton, the normal, and shear stresses in plane strain condition are written as Zienkiewicz, Chang, and Bettess (1980): where and are shear modulus and Poisson’s ratio. The final forms of the governing equations are obtained by substitution of Eqs. (9)–(11) into Eqs. (6) and (7) and are expressed as:
Effects of traffic intensity and travel speed on forest soil disturbance at different soil moisture conditions
Published in International Journal of Forest Engineering, 2022
Sara Sadeghi, Ahmad Solgi, Petros A. Tsioras
Ground-based skidding operations that transfer the weight of the machinery and its log load onto a small soil surface area result in soil disturbances, such as increased soil compaction (Naghdi et al. 2015) that are diffused in the various soil layers. Compaction of the soil increases bulk density, reduces soil porosity, decreases infiltration rates, and lowers soil permeability (Froehlich et al. 1981). It has been well established that these changes in soil physical properties increase surface runoff and erosion, and create less-favorable soil environments for plant growth (Solgi et al. 2019a, 2019b). Not only topsoil is affected but also the subsoil, with the latter exhibiting longer lasting adverse effects (Rab 2004). Careful planning of landing locations and skid trail systems before logging commences is intended to reduce damage to the soil and the residual stand (Solgi et al. 2017; Naghdi et al. 2018b).
Influence of geocell on bearing capacity and settlement of railway embankments: an experimental study
Published in Geomechanics and Geoengineering, 2022
Farshad Astaraki, Morteza Esmaeili, Mohammad Reza Roozbini
In the second step and after preparation of the subgrade, to construct the modified subgrade and the embankment body, the soil was firstly moistened up to its optimal moisture content outside the chamber. Then, the prepared soil was compacted inside the chamber in 5–7 cm thicknesses layers using a 36 kg roller. With a view to meet the desirable density, the roller passing numbers were set as 15 times. Furthermore, the in-situ density test was regularly carried out using the sand cone method to ensure achieving the desired density. It should be noted that for each reinforced embankment, the geocell layers placed from top to bottom of the embankment crest without any intervals as presented in Figure 12. In this research, 6 laboratory models including 5 reinforced embankments and one unreinforced embankment were constructed in similar aforementioned way. As already mentioned, the ELM1 to ELM5 refers to reinforced embankments with 1, 2, 3, 4, and 5 geocell layers, respectively.