The density of the seat belt (βd) is the ratio between the fixed part of the protective belt and the total volume of the protective belt. It has the same meaning as the concept of porosity, i.e. the ratio of the open part of the protective belt to the total volume. The two terms complement each other. Mineral solids themselves may also contain internal pores (intragranular porosity), which may or may not be connected to the surface of the mineral and thus to the network of intergranular pores. Figure 2.5 shows two intragranular porosity scanning electron micrographs. Wood et al. (1990) measured intracrystalline porosity in the quartz-rich glacial sands of Cape Cod, Massachusetts, and found that, on average, 9% of grain volume consisted of internal pore space. Ball et al.

(1990) found 1-5% internal pore space in leached sand grains from Canadian Forces Base Borden, Ontario; This sand consisted mainly of quartz and feldspar with small amounts of calcite. Here we use the weighting porosity determined by the water saturation method (φw) as an approximation of the NMR porosity (φN), since these two porosities should theoretically be identical. The φw is usually calculated by estimating the volume of water in coal, and the φN is calculated based on estimating the volume of liquid NMR signals in coal. Theoretically, NMR porosity represents the volume fractions of the pores occupied by bound (irreducible) and free (producible) water. By definition, bound water is the amount of water in coal that cannot be recovered during HD production, while free water can be recovered. Thus, NMR porosity can be divided into IP, which corresponds to the bound water fraction φNI, and producible porosity (PP), which corresponds to the free water fraction φNP. φNI and φNP can be determined by comparing the signal of a 100% water-saturated sample with that of a water-saturated irreducible sample. The porosity of the surface soil generally decreases with increasing particle size.

This is due to the formation of soil aggregates in finer structured surface soils when exposed to soil biological processes. Aggregation includes particle adhesion and higher compaction resistance. The typical bulk density of sandy soils is between 1.5 and 1.7 g/cm3. This results in a porosity between 0.43 and 0.36. The typical bulk density of clay soils is between 1.1 and 1.3 g/cm3. This results in a porosity between 0.58 and 0.51. This seems counterintuitive, as clay soils are said to be heavy, which implies lower porosity. Heavy apparently refers to a gravitational effect of moisture content combined with terminology that goes back to the relative strength required to pull a tillage device through loamy soil to the moisture of the field relative to the sand. An increase in the porosity of the filter tube is out of the question, as very small germs could pass through. These sample phrases are automatically selected from various online information sources to reflect the current use of the word “porosity”.

The views expressed in the examples do not represent the views of Merriam-Webster or its editors. Send us your feedback. Modern carrot measurements are usually closer to total porosity because they are made with inert liquids on cleaned and dried caps. The quantitative relationship between them is given in equation 2.1, which is repeated below for simplicity. Go back quite far and you will find that the porosity comes from the Greek word poros for “pore”, which means “passage”. Most pants have porosity, as you unfortunately notice when you spill soup on them – the soup passes. On the other hand, a raincoat has no porosity because it is waterproof. If your roof leaks during the rain, it has some porosity, which is a problem.

You can remember porosity by imagining fluids flowing through things. Porosity is the volume ratio of pores and fractures in coal. Unlike traditional oil and gas deposits (e.g. sandstone), coal pores and fractures vary widely, making it difficult to accurately measure coal porosity. According to the above methods and principles, the following sections explain the division of porosity zones and intervals into different oil-rich subsidence structural zones in the Jizhong Depression. Fluid-productive sandstones have porosities between 0.05 and 0.4 or between 5% and 40%. Although the porosity of the carbonate base material is virtually zero, the total porosity of carbonate rocks can be significant due to natural fractures in the rocks. The precursors of igneous rocks have no porosity, but their natural fractures form a certain degree of total porosity, in which hydrocarbons have been discovered in recent years. The porosity of a layer of rock or sediment is an important factor to consider when assessing the potential volume of water or hydrocarbons it may contain. Sediment porosity is a complex function of many factors, including but not limited to: burial rate, depth of burial, type of fluids connaten, nature of overlying sediments (which can impede fluid flow). A commonly used relationship between porosity and depth is given by the equation of Athy (1930): [2] Porosity is the property of being porous or full of tiny holes. Fluids go directly through things that have porosity.

Britannica English: Translation of porosity for arab speakers The porosity of the reservoir rock can be measured in the laboratory by analysis of core samples. It can also be estimated from open well logs. The porosity factor is often used to estimate hydrocarbon reserves. The optical density (βr) has a reciprocal or complementary implication as optical porosity. It is defined as the ratio between the projected solid surface and the total lateral view area of a protective belt. where φN, φNI and φNP are the total NMR, IP and PP porosity, respectively; BVI is the bound fluid index (or bounded volume) that can be calculated by the total fraction of spectral area at the condition of Sir. FFI is the free fluid index (or volume); BVI + FFI represents both the free liquid and the bound liquid, which can be calculated by the total fraction of the spectral area in the Sw state. The porosity zone can be divided into low, high and exceptionally high. The low porosity zone refers to the area where the porosity is below the lower limit of the effective reservoir on the depth porosity diagram (Fig. 5.7B, zone A). In the high quality zone, the porosity in the depth porosity diagram is between the lower limit and the maximum normal porosity (Fig.

5.7B, zone B). In the exceptionally high quality zone, the porosity in the diagram is higher than the porosity on the maximum normal porosity evolution curve (Fig. 5.7B, zone C). In this way, all the organic matter is burned and the tube returns to its former porosity. Optical porosity and optical density. Although the porosity or density of the protective belt is important in describing the structure of the protective belt, due to the three-dimensional nature of the pores through which the wind flows, it is almost impossible to physically measure the aerodynamic porosity of plants. Therefore, great efforts have been made to find an alternative measure. Optical porosity (β), a two-dimensional measure of porosity defined as the simple ratio of the perforated surface to the total surface area on the vertical section of a protective belt, was used as a descriptor for the structure of the protective belt. It has proven to be a promising alternative to aerodynamic porosity, especially for narrow seat belts. In general, optical porosity is not synonymous with aerodynamic porosity, because it does not take into account the three-dimensional nature of the pores, but for a tight artificial windbreak, β is close to βa. Porosity is an important parameter for the characterization of material microstructures.

It corresponds to the volume of spaces that can hold liquid, compared to the total volume of the material. The pore system, which is considered a network of communicating or non-communicating pores and small channels, can be divided into several porosity classes. “Residual porosity” or “closed porosity” refers to the part of the porous system consisting of closed pores without communication with the rest of the porous spaces and the outside. This type of porosity is not involved in the phenomenon of mass transfer, but has an influence on the strength of the material. In addition, the communicating pores form the “efficient” or “open” porosity, which is the porosity that takes into account the volume of accessible or connected pores. The description of the pore system can be refined taking into account the distribution of pore size. Figure 2.5. Scanning electron micrograph (SEM) with intragranular porosity on the surface of a quartz sand grain (left) and feldspar crystal in sandstone (right). Von Trewin, N., 1988, Use of the scanning electron microscope in sedimentology, in sedimentology techniques, Blackwell Scientific Publications. “Porosity.” Merriam-Webster.com Dictionary, Merriam-Webster, www.merriam-webster.com/dictionary/porosity. Retrieved 11 October 2022. The porosity of the soil is complex.

Traditional models consider porosity as continuous. This does not take into account abnormal characteristics and gives only approximate results. In addition, it cannot help model the influence of environmental factors that affect pore geometry. A number of more complex models have been proposed, including fractals, bubble theory, crack theory, the Boolean grain process, the compacted sphere, and many other models. The characterization of the interstitial space in the soil is an associated concept. Casting porosity is a consequence of one or more of the following factors: gasification of impurities at molten metal temperatures; shrinkage, which occurs when molten metal solidifies; and unexpected or uncontrolled changes in temperature or humidity.