Page 1
The edge effect was determined by the adhesion of the ends of the cylinder connected with epoxy glue.
The edge effect occurs when determining adhesive strength when films have a limited length or width. For films of relatively large size, the edge effect is insignificant.
The edge effect - partial association with a mixed solvent - should be eliminated by saturating the chamber with solvent vapor. It is caused by varying degrees of evaporation across the width of the plate, with the rate of evaporation being greater near the edges than in the middle. This is due to two factors: the large volume of the chamber compared to the volume of the plate and the unsaturated atmosphere behind the plate. Therefore, the Rf value of the solute is higher near the edges of the plate, and the line containing the spots of the solute applied across the plate will have depressions.
The edge effect is explained by different evaporation of the solvent across the width of the plate, with the evaporation rate being greater at the edges of the plate than in the middle. This is due to the large volume of the chamber relative to the volume of the solvent and the unsaturation of its atmosphere.
The edge effect will increase if turbulent flow is created in the area of the ends of the cylinder.
The edge effect distorts the field at a distance approximately equal to the width of the gap between the electrodes. This condition is not necessary for the equipotential space between the source and the input diaphragm. Finally, the contact potential difference between the electrodes shifts the delay curve along the abscissa axis, and scattered particles distort its shape.
The edge effect is a phenomenon when, when exposing the original (for example, on a selenium plate), a charge of static electricity in illustrations with large painted surfaces seems to accumulate along the edges of the image. During development, the powder settles in these places, and the middle of the image receives the smallest amount of it. To eliminate the edge effect, three methods are used to reproduce such originals: single-stage, multi-stage and pre-screening.
There is no edge effect on the cathode, which occupies the entire cross-section of the electrolyte, if the walls and bottom of the bath do not conduct electric current.
The edge effect, as already mentioned, increases the dose rate calculated in this way by 8 - 12% compared to the experimental one.
The edge effect is noticeably manifested in cases where the chamber is not saturated with vapors and contains a mixture of solvents that differ in volatility. The content of volatile components in the liquid gradually decreases and the content of less volatile components relatively increases. Changing the composition of the solvent system significantly affects the separation of substances and the Rf value of the separated components. To eliminate edge effects, it is necessary to ensure uniform saturation of the chambers with solvent vapors before starting chromatography.
The edge effect in a solid cylinder is determined by only one variable and can be studied and tabulated in a general form.
The edge effect is an increase in species diversity in transition zones between communities (ecotones). [ ...]
EDGE EFFECT is a tendency to increase (bio)diversity and density of organisms on the outskirts of two neighboring biogeocenoses and transitional territories between them. [ ...]
The edge effect - partial association with a mixed solvent - can be eliminated by saturating the chamber with solvent vapor. It is caused by varying degrees of evaporation across the width of the plate, with the rate of evaporation being greater near the edges than in the middle. This is due to two factors: the large volume of the chamber compared to the volume of the plate and the unsaturated atmosphere behind the plate. Therefore, the value of R) of the solute is higher near the edges of the plate, and the line on which the spots of the solute applied across the plate are located will have depressions. [ ...]
Border or edge effect. An important feature of the structural characteristics of biocenoses is the presence of habitat boundaries for different communities. However, they are rarely clearly defined, since neighboring biocenoses gradually transform into one another. As a result, a rather extensive border (edge) zone arises, characterized by special conditions. [ ...]
In the forest zone, the influence of the edge effect on the ratio of total evaporation from the forest and field is weakly expressed, and the value of the age of the planting appears only in small catchments. As a result, for this zone the ratio of total evaporation and runoff from forest and field catchment areas is determined mainly by climatic factors. Therefore, here, most often, there is a clear increase in the average long-term annual runoff with an increase in the forest cover of the catchment, which also follows from observational materials on the flat territory. [ ...]
In terrestrial communities, the concept of the "edge effect" is particularly applicable to bird populations. Beecher (1942) attempted to carry out a complete census of bird nests in an area occupied by a number of marshy and upland communities. It turned out that in a large swamp, completely overgrown with cattails, there were fewer nests than in an area of equal size, where the same plant community formed many scattered small areas. In general, bird population densities increased as the ratio of boundary length to area occupied by the community increased. It is well known that the density of songbirds is higher on various types of estates, in the vicinity of colleges and the like, which consist of mixed habitats and, therefore, are characterized by a greater extent of “boundaries” compared to large homogeneous!’ areas of forest or fields. [ ...]
In a landscape, people give preference to the edge effect: water - shore, forest edge - field, mountains - seas, hilly areas - flat plain, earth - sky. American specialists, writes V.A. Nikolaev (2003) explain this by the psychological and even physiological needs of humans in a diverse natural environment. The same researchers showed that homogeneous tree plantations, landscapes of old swampy lowlands, as well as areas disfigured by humans, the so-called anthropogenic badlands, produce a repulsive effect.” It was absolutely right that attention was focused on the physiological need of a person; the automaticity of saccades is precisely such a physiological need. The great diversity of nature creates excellent conditions for the eye to work, and this is what delays tourists. While in a homogeneous environment there are not enough elements to fix the gaze and this is what causes a repulsive effect, tourists do not linger and quickly leave such places. In this case, the eyes seem to be telling the legs: “There is nothing to do here, let’s move on.” And tourists have a well-known motto: “Go where your eyes lead.” The eyes look at beautiful places and do not look at ugly ones, from which the tourist immediately turns away and goes in the other direction. [ ...]
We will assume that the field area is sufficiently large and that the edge effect can therefore be neglected. This allows us to describe agrophytocenosis as a non-stationary one-dimensional system with two independent variables: vertical coordinate x and time t. To build a model, it is therefore necessary to select a certain unit area of the field. The state of the abiotic part of the system at each moment in time is characterized by the vertical distribution of various physical variables: radiation, temperature and humidity of the air in the crop, temperature and humidity of the soil, etc. (Fig. 4.1). In the same way, the biological part of the system is characterized by a set of vertically distributed variables: the density of the assimilating surface of phytoelements s (je) and the absorbing surface of roots co (je), the density of individual components of phytomass (carbohydrates, amino acids, proteins) and phytomass as a whole, etc. In dynamics, everything these quantities change. The task of modeling is precisely to describe the changes in these variables in space (i.e., vertically) and in time. [ ...]
In aquatic ecosystems, compared to terrestrial ones, the zones of manifestation of the edge effect are less constant in time and space, their dynamics depend on hydrophysical factors (Odum, 1975, 1986). Thus, in the ecotones of the contact zones of river and reservoir waters, the areas where the edge effect is maximally manifested are concentrated at river mouths during the period of hydrological spring. In the summer, when the flow and water level in the rivers decrease, and the reservoir level is still quite high, they move up the river bed. In autumn, due to rain floods and a drop in the water level in the reservoir, they are again recorded at river mouths. [ ...]
In nature, glacial and sediment loads and erosion greatly smooth out this edge effect. Seismic studies carried out in this area make it possible to compare the observed (Fig. 7.1, b) and theoretically calculated foundation relief (Fig. 7.4, d). A comparison of the theoretically calculated relief with the observed one (taking into account the load of the sedimentary strata) showed that the model used gives satisfactory agreement with the results in terms of the most general characteristics, namely: the nature of the change in relief at the contacts of lithosphere of different ages and the gradient of increasing depth of the basement with distance from the ridge axis. At the same time, the actually observed relief of the surface of the oceanic lithosphere is characterized by significant ruggedness, which cannot be explained only by the features of the thermal structure. [ ...]
In such transition zones, a concentration of species and individuals occurs, the so-called edge effect, or edge effect, is observed. The rule of ecotone, or edge effect, is that at the junctions of biocenoses the number of species and individuals in them increases. [ ...]
The photo illustrates the desired ratio of young and mature vegetation and the concept of the “edge effect” (Picozzi, 1968). [ ...]
As a model cellulose, 3-cellobiose has the disadvantage of being significantly influenced by "edge effects", but a complete X-ray diffraction analysis of the higher members of the homologous series has not yet been performed. The powder X-ray diffraction patterns of the homologues above cellotetraose have a strong resemblance to the x-ray diffraction pattern of cellulose II. IR spectra of cellotetraose and especially the cellopentaoses are similar to the IR spectra of cellulose II (after deuteration of the less ordered regions) in the region of O-H stretching vibrations, indicating the involvement of all these groups in hydrogen bonding. Small differences between even and odd members should be expected. homologous series, depending on whether the same or different terminal units are adjacent. Very thin single crystals were grown for cellotriose, but it was not possible to carry out analysis beyond the determination of the probable space group. Data from infrared spectra and the X-ray diffraction pattern of the powder indicate that the chains are packed in. cellodextrins, starting with cellotetraose, is very similar to the chain packing in cellulose II, although the period of identity along the chain axis depends for lower homologues on the length of the molecule. Analysis of single crystals of cellotetraose and cellopentaose can provide very interesting data, but it is very tedious. According to a report on the study of a two-dimensional projection (x, z; the dimensions of the axes are the same as those indicated in Table 1.13), cellotetraose crystals have a triclinic unit cell, the length of which is twice the length of the anhydrocellobiose unit of the macromolecule. These preliminary single crystal data may provide evidence that the cellulose II unit cell is triclinic and contains parallel oriented chains. [ ...]
The modern concept of ecotones includes not just the phenomenon of physical contact of two ecosystems, but the obligatory presence of an edge effect, i.e. trends towards increasing biodiversity and abundance in the mixing zone (Kharchenko, 1991a). Ecotone, as defined in the UNESCO program (MAB) (Holland, 1988; Hillbricht-Ilkowska, 1989): “... a transitional area between adjacent ecological systems, possessing a number of characteristics clearly recorded in spatiotemporal coordinates and determined by the strength of connections and intensity interactions between neighboring ecosystems.” [ ...]
Joint research of the Institute of Electric Welding named after. E. O. Paton and Yuzhgipronefteprovod showed that in order to reduce edge effect stresses in the junction of the wall and the bottom and increase the reliability of the design of large-capacity tanks (50,000 and 100,000 m3), it is necessary to make the lower chords of the walls from high-strength steels, reduce the thickness of the outer parts of the bottom and make the bottom from high-strength steel. [ ...]
This formula is valid for Reynolds numbers E[...]
Ecotones—transition zones between communities—are characterized by high species diversity, and the increase in species diversity here is called the edge effect. [ ...]
The most favorable conditions for the existence of many species are characteristic of transition zones between communities, which are called ecotones, and the tendency to increase species diversity here is called the edge effect. [ ...]
Consequently, under the conditions of complex anthropogenic pollution of the contact zone of river and reservoir waters during the growing season, a change occurs in the localization of the area of maximum manifestation of the edge effect: in spring and autumn it manifests itself at the upper boundaries of the contact zone, while on other - control rivers - at the mouth. [ ...]
To explain this phenomenon, data on zooplankton in the water contact zone of the river were analyzed. Koshta, which receives waste from the Ammophos production plant. Here, during the growing season, no changes were observed in the location of zones of maximum manifestation of the edge effect. The trophic structure was constantly dominated by primary filter feeders and vertical feeders, obtaining food in the water column. [ ...]
The reproduction rate depends on the crop, soil and climatic conditions and agricultural technology (especially the seeding rate). In the early stages of the test, in order to increase the multiplication factor, seeding rates lower than those usually accepted in production are used; in addition, the multiplication factor increases due to the edge effect, and therefore the higher the proportion of edge rows in the plot, the higher it is. So, with a seven-row plot it will be higher than with a ten-row plot. It is not recommended to greatly reduce the seeding rate, as the test becomes atypical. As an exception, this technique is used when the main task of the nursery is to obtain more seeds (for example, when sowing /h). Table 1 shows approximate data necessary for planning the selection process scheme when working with spring wheat in the Non-Chernozem zone. It is also necessary to take into account the consumption of seeds for analyzing the quality of the sample (see. [ ...]
Wildlife management is not just about producing game animals on lands that are not suitable for anything else; it must deal with their products in those areas that are used for agriculture or forestry. Hawkins (1940) compared the landscape of Wisconsin as it appeared to the first European settlers in 1838 with its appearance after 100 years of intensive farming; vast tracts of forests and prairies are fragmented into numerous small areas, interspersed with fields, roads and villages: local game birds - meadow grouse and quail - are completely replaced by introduced species - pheasant and gray partridge, which have already been adapted to exist in various areas of the European continent with intensive agriculture. Thus, as landscapes become domesticated, so do wild populations. Under these conditions, food ceases to be the main limiting factor and habitable space, diseases and enemies come to the fore. The principles of predator-prey interactions and the concepts of optimal yield are discussed extensively in Chap. 7. [ ...]
Thus, the contact zones of river and reservoir waters in the mouth areas of small rivers that are tributaries of the reservoir are ecotones in which contact of two types of water masses with their characteristic zooplankton occurs. Here, new complexes are formed that differ from the zooplankton of bordering systems and tend to increase species diversity and quantitative abundance, i.e. corresponding to the concept of edge effect. [ ...]
Chromatograms are usually developed by ascending chromatography in closed chambers, the dimensions of which are slightly larger than the dimensions of the plates. More complex is the sandwich chamber (c-chamber), in which the cover plate, together with the plate on which the adsorbent is applied, forms a small internal chamber, which contributes to its good saturation. When using a c-camera, the spots of separated substances are smaller and there is no edge effect. [ ...]
FRAGMENTATION (f.) - the process of dividing a single ecosystem into isolated areas, usually as a result of human economic activity. Examples of F. are small spots of natural ecosystems, steppe or forest, in arable land, clearings of meadow vegetation in the forest. Physics transforms single ecosystems into “islands” with their own biological diversity (see Island biogeography). The preservation of the biodiversity of “islands” is also influenced by the edge effect, since the outer part of the “island” differs in its conditions from the inner one and special types of ecotone communities are formed on it, for example, forest edges, in which species of forests, meadows and edge plant species are represented and their companions are insects. An example of natural forestry is highland ecosystems, which are found only at the peaks and are separated by vegetation at lower absolute altitudes. [ ...]
The only exception was 1987 - unfavorable weather conditions and the presence of toxic substances in the water after an emergency release of 1 thousand m3 of concentrated sulfuric acid into the river (Flerov, 1990). The number of zooplankton in the mouth at that time did not exceed 18.1 thousand specimens/m3, and the biomass was 0.02 g/m3 (Rivier, 1990). Taking this into account, it can be assumed that the constant presence of toxic substances at the mouth of the river. Jagorbs have a decisive influence on zooplankton and the manifestation of the edge effect. [ ...]
Chromatography plates with a thin layer of KSK brand silica gel. On ten glass plates measuring 3x18 cm, apply a uniform layer of a mixture of 14 g of silica gel ground and sifted through a sieve (hole diameter 0.1 mm), 0.85 g of gypsum and 37.6 ml of distilled water (silica gel is pre-calcined at 700 ° C in for 2 hours to remove organic matter). The plates are air dried at room temperature and stored in a desiccator. To reduce edge effects, a layer of sorbent 0.5 cm wide is removed from the sides of the plates. [ ...]
The population of invertebrate thickets of higher aquatic vegetation is a specific biocenosis, diverse in species composition and quantitative abundance. This typical ecotone community develops at the boundary between a reservoir and a catchment area under dynamic and diverse conditions (Zhgareva, 2001). According to the definition of F.D. Mordukhai-Boltovsky (1974) the zone of macrophyte thickets acquires the character of “another state”, located within the aquatic ecosystem, but living a different life. In these biotopes, the edge effect is enhanced by the fact that in shallow water, water, soil and plants border in a narrow space. The predominance of a particular community of organisms in the biocenosis is determined by the location, depth, total area and density of overgrowth, as well as the ratio of areas occupied by air-water, floating and submerged plants and their morphological structure (Zimbalevskaya, 1981). In addition, macrophyte zoocenoses are influenced by the type of water body, as well as the degree of anthropogenic pressure on the ecosystem. [ ...]
Thus, the results showed that the greatest quantity and species diversity of zooplankton is observed in mixing zones of water masses that differ in physical and chemical parameters: tributary waters with the waters of the reservoir and waters of river reaches with the waters of the Main Reservoir of the Rybinsk Reservoir. Here contact occurs between groups of zooplanktonic animals characteristic of adjacent planktonic systems. As mentioned above, according to the modern concept, the presence of a tendency to increase the diversity and quantitative abundance of communities in contact zones - the edge effect - allows the selected zones to be considered as ecotones. [ ...]
To take into account field germination, plant survival and crop structure (as well as damage by diseases, pests and determination of varietal purity), trial sites are allocated in competitive variety testing. Three test plots are identified in two non-adjacent repetitions on plots of each variety. For continuous crops, the area of each plot is set to Vu m2, for legumes - Ve> for crops cultivated in wide rows - Vg m3. The plots cover two rows (in wide-row sowing, one). Platforms are not laid on the outer rows due to their atypicality (edge effect). It is necessary that the areas cover the rows sown by all coulters of the seeder (except for the outer ones), and, if possible, the representation of these rows should be the same. Test plots are placed diagonally across the plot, trying to ensure that they cover the rows that are furthest apart from each other. [ ...]
An ecotone is a transition between two or more different communities, such as between forest and grassland or between soft and hard ground marine communities. This is a border zone, or a “tension” zone, which can have a significant linear extent, but is always narrower than the territory of the neighboring communities themselves. Typically, an ecotone community contains a significant proportion of species from each of the overlapping communities, and sometimes also species unique to the ecotone. Often both the number of species and the population density of some of them are higher in an ecotone than in the communities lying on either side of it. The tendency to increase the diversity and density of living organisms at the boundaries of communities is known as the edge effect. [ ...]
The apparatus of Linke and Israel has a number of advantages over other instruments used to measure heavy air ions. First of all, it has several times smaller dimensions (convenient for expeditions) and significant sensitivity. With a potential difference of 200 volts, it makes it possible to capture all azroions. In addition, this apparatus has two capacitors and, accordingly, two electrometers, so that air is simultaneously passed along two paths and both positive and negative air ions are simultaneously captured. This makes it possible to simultaneously determine the unipolarity coefficient. In addition, the device measures the amount of air passed through and requires 1 to 3 minutes to complete all measurements. To eliminate the harmful influence of the capacitor edge effect, due to which some of the light air ions do not enter the measuring capacitor, an additional capacitor is installed in the suction tube of the device. It traps light air ions before they enter the main measuring capacitor. This device makes it possible to more accurately measure the amount of air ions. [ ...]
Currently, there is a trend towards a significant increase in the size of steel tanks for storing petroleum products, which corresponds to the continuous growth of oil production and refining. The economic advantage of increasing the volume of tanks is expressed in a decrease in the specific consumption of steel, a decrease in the degree of evaporation of petroleum products, and a reduction in the total area of oil storage facilities. However, at the same time, the height of the tanks and the calculated wall thickness increase, which worsens its performance under repeated loads. An increase in the diameter of the tank, in turn, leads to an increase in radial displacements. The combined action of the last two factors aggravates the danger of brittle fracture of the body, especially in the lower most loaded part, which is also subject to the action of the edge effect. For large-volume tanks, along with conventional low-carbon steels, as a rule, metal of increased and high strength is used. Reservoirs with a capacity of 50 and 100 thousand m3 with floating roofs are considered promising.
Material from Wikipedia - the free encyclopedia
Edge effect, edge effects- influence of boundaries.
- Edge effects in electromagnetism:
- Reduce the inductance of the coil.
- Edge effects, shape effects have to be taken into account when designing electrical machines and electrical measuring instruments.
- Border effects of development in photography.
- Edge effect rule, condensation of life at the boundaries of ecosystems.
Modeling
- Edge effect in process modeling - a disadvantage, limitation of a model that implies continuity, unlimitedness of the process in space or time.
- Edge effect in role-playing games, game modeling - the influence of the moments of the beginning and end of the game on the actions of the players and the work of the models adopted in the game.
- Edge effect in the operation of cellular automata
In psychology
Edge effect- decision-making phenomenon. Characterized by an overestimation of probable events and an underestimation of unlikely events. In particular, the individual usually completely ignores very unlikely events even if they are extremely significant.
[…] G. Ebbinghaus also established that with close attention to an event, experiencing it once is enough to accurately reproduce it in the future. Another finding was that when learning a long series, the material at the ends is better recalled (the “edge effect”).
see also
Write a review about the article "Edge effect"
Notes
__DISAMBIG__Excerpt describing the Edge Effect
Pierre, unconscious from fear, jumped up and ran back to the battery, as the only refuge from all the horrors that surrounded him.While Pierre was entering the trench, he noticed that no shots were heard at the battery, but some people were doing something there. Pierre did not have time to understand what kind of people they were. He saw the senior colonel lying with his back to him on the rampart, as if examining something below, and he saw one soldier he noticed, who, breaking forward from the people holding his hand, shouted: “Brothers!” – and saw something else strange.
But he had not yet had time to realize that the colonel had been killed, that the one shouting “brothers!” There was a prisoner who, in front of his eyes, was bayoneted in the back by another soldier. As soon as he ran into the trench, a thin, yellow, sweaty-faced man in a blue uniform, with a sword in his hand, ran at him, shouting something. Pierre, instinctively defending himself from the push, since they, without seeing, ran away from each other, put out his hands and grabbed this man (it was a French officer) with one hand by the shoulder, with the other by the proud. The officer, releasing his sword, grabbed Pierre by the collar.
For several seconds, they both looked with frightened eyes at faces alien to each other, and both were at a loss about what they had done and what they should do. “Am I taken prisoner or is he taken prisoner by me? - thought each of them. But, obviously, the French officer was more inclined to think that he had been taken prisoner, because Pierre’s strong hand, driven by involuntary fear, squeezed his throat tighter and tighter. The Frenchman wanted to say something, when suddenly a cannonball whistled low and terribly above their heads, and it seemed to Pierre that the French officer’s head had been torn off: he bent it so quickly.
Pierre also bowed his head and let go of his hands. Without thinking any more about who took whom prisoner, the Frenchman ran back to the battery, and Pierre went downhill, stumbling over the dead and wounded, who seemed to him to be catching his legs. But before he had time to go down, dense crowds of fleeing Russian soldiers appeared towards him, who, falling, stumbling and screaming, ran joyfully and violently towards the battery. (This was the attack that Ermolov attributed to himself, saying that only his courage and happiness could have accomplished this feat, and the attack in which he allegedly threw the St. George crosses that were in his pocket onto the mound.)
For a long shell, the deflection can be represented as
here is the deflection of the shell in a momentless stressed state, -
where arbitrary constants are determined from the fixation condition at - from the boundary conditions at . It is assumed that the influence of the fastening conditions at does not affect each other. The solutions express the edge effect. For example in Fig. 16.17 we have
The possibility of representing (123) follows from the fact that differential equation (97) contains a small parameter at the highest derivative (flexural stiffness D for thin shells is a small value). If are sufficiently smooth functions and their derivatives can be neglected in comparison with small functions, then a particular solution can be taken in the form
Deflection expresses a momentless stress state in which. Solution (123) represents an approximate solution to the cylindrical shell equation. This solution is called asymptotic, since its accuracy increases as . The approximate solution allows for separate determination of arbitrary constants for boundary conditions and gives a general approximate formula for a particular solution (formula (126)).
Notes. 1. Disturbance zones arise not only in the zones of shell fastening, but also in the zones where concentrated impacts are applied.
2. An equation with a small parameter for the highest derivative and the boundary effect for such equations are also found in other problems of mathematical physics (for example, in problems of thermal conductivity).
Short shells.
For short shells, it is convenient to represent the solution of equations (98) using normal fundamental functions (Krylov functions). We write the solution to equation (98) in the form
where the Krylov functions are equal
expresses a particular solution to equation (98). For short shells, approximate solution (123) is unsuitable, since the edge effect zones occupy the entire length of the shell. Models of the strength of short shells are based on solution (127).
When assessing strength, the various dangers of uniformly distributed stresses throughout the wall thickness (stresses from efforts) and bending stresses, which decrease when plastic deformations occur, are taken into account.