Misplaced Pages

#318681

39-642: The La Mesa Dam and Reservoir is an earth dam in Quezon City , Philippines . Its reservoir can hold up to 50.5 million cubic meters (1,780 million cubic feet), occupying an area of 27 square kilometers (10 sq mi). It is part of the Angat - Ipo -La Mesa water system, which supplies most of the water in Metro Manila . The La Mesa Dam was constructed in 1929 as the Novaliches Reservoir during

78-523: A network comprising different types of computers, potentially with vastly differing memory sizes, processing power and even basic underlying architecture. In algebra, homogeneous polynomials have the same number of factors of a given kind. In the study of binary relations , a homogeneous relation R is on a single set ( R ⊆ X × X ) while a heterogeneous relation concerns possibly distinct sets ( R ⊆ X × Y ,   X = Y or X ≠ Y ). In statistical meta-analysis , study heterogeneity

117-401: A big number of different terms for environmental heterogeneity, often undefined or conflicting in their meaning. Habitat diversity and habitat heterogeneity are a synonyms of environmental heterogeneity. In chemistry , a heterogeneous mixture consists of either or both of 1) multiple states of matter or 2) hydrophilic and hydrophobic substances in one mixture; an example of

156-418: A dam and the filling of the reservoir behind it places a new weight on the floor and sides of a valley. The stress of the water increases linearly with its depth. Water also pushes against the upstream face of the dam, a nonrigid structure that under stress behaves semiplastically, and causes greater need for adjustment (flexibility) near the base of the dam than at shallower water levels. Thus the stress level of

195-422: A drain layer to collect seep water. A zoned-earth dam has distinct parts or zones of dissimilar material, typically a shell of locally plentiful material with a watertight clay core. Modern zoned-earth embankments employ filter and drain zones to collect and remove seep water and preserve the integrity of the downstream shell zone. An outdated method of zoned earth dam construction used a hydraulic fill to produce

234-468: A heterogeneous substance in many aspects; for instance, rocks (geology) are inherently heterogeneous, usually occurring at the micro-scale and mini-scale. In formal semantics , homogeneity is the phenomenon in which plural expressions imply "all" when asserted but "none" when negated . For example, the English sentence "Robin read the books" means that Robin read all the books, while "Robin didn't read

273-448: A rock-fill dam, rock-fill is blasted using explosives to break the rock. Additionally, the rock pieces may need to be crushed into smaller grades to get the right range of size for use in an embankment dam. Earth-fill dams, also called earthen dams, rolled-earth dams or earth dams, are constructed as a simple embankment of well-compacted earth. A homogeneous rolled-earth dam is entirely constructed of one type of material but may contain

312-404: A small sustained overtopping flow can remove thousands of tons of overburden soil from the mass of the dam within hours. The removal of this mass unbalances the forces that stabilize the dam against its reservoir as the mass of water still impounded behind the dam presses against the lightened mass of the embankment, made lighter by surface erosion. As the mass of the dam erodes, the force exerted by

351-686: A thick suspension of earth, rocks and water. Therefore, safety requirements for the spillway are high, and require it to be capable of containing a maximum flood stage. It is common for its specifications to be written such that it can contain at least a one-hundred-year flood. A number of embankment dam overtopping protection systems were developed in the early 21st century. These techniques include concrete overtopping protection systems, timber cribs , sheet-piles , riprap and gabions , Reinforced Earth , minimum energy loss weirs , embankment overflow stepped spillways , and precast concrete block protection systems. All dams are prone to seepage underneath

390-579: A watertight core. Rolled-earth dams may also employ a watertight facing or core in the manner of a rock-fill dam. The frozen-core dam is a temporary earth dam occasionally used in high latitudes by circulating a coolant through pipes inside the dam to maintain a watertight region of permafrost within it. Tarbela Dam is a large dam on the Indus River in Pakistan , about 50 km (31 mi) northwest of Islamabad . Its height of 485 ft (148 m) above

429-420: Is a hypernym for different environmental factors that contribute to the diversity of species, like climate, topography, and land cover. Biodiversity is correlated with geodiversity on a global scale. Heterogeneity in geodiversity features and environmental variables are indicators of environmental heterogeneity. They drive biodiversity at local and regional scales. Scientific literature in ecology contains

SECTION 10

#1732855019319

468-544: Is a mixture of two or more compounds . Examples are: mixtures of sand and water or sand and iron filings, a conglomerate rock, water and oil, a salad, trail mix , and concrete (not cement). A mixture can be determined to be homogeneous when everything is settled and equal, and the liquid, gas, the object is one color or the same form. Various models have been proposed to model the concentrations in different phases. The phenomena to be considered are mass rates and reaction. Homogeneous reactions are chemical reactions in which

507-591: Is an earth dam or a terrain dam ( caldera alike) with a height of 24 meters (79 ft). The elevation at its crest is 82.5 meters (271 ft) while the elevation at its overflow section is 80.15 meters (263.0 ft). These elevations can be observed from SM Fairview Mall , the Basement Level and First Floor at the Round about going bayan. The La Mesa Reservoir has a maximum capacity of about 50.5 million cubic meters (1,780 million cubic feet). Water from

546-438: Is distinctly nonuniform in at least one of these qualities. The words homogeneous and heterogeneous come from Medieval Latin homogeneus and heterogeneus , from Ancient Greek ὁμογενής ( homogenēs ) and ἑτερογενής ( heterogenēs ), from ὁμός ( homos , "same") and ἕτερος ( heteros , "other, another, different") respectively, followed by γένος ( genos , "kind"); -ous is an adjectival suffix. Alternate spellings omitting

585-553: Is when multiple studies on an effect are measuring somewhat different effects due to differences in subject population, intervention, choice of analysis, experimental design, etc.; this can cause problems in attempts to summarize the meaning of the studies. In medicine and genetics , a genetic or allelic heterogeneous condition is one where the same disease or condition can be caused, or contributed to, by several factors, or in genetic terms, by varying or different genes or alleles . In cancer research , cancer cell heterogeneity

624-751: The American colonial era in the Philippines . Sometime between 1920 and 1926, the Metropolitan Water District (a predecessor agency of the Metropolitan Waterworks and Sewerage System ) decided to build a replacement for the old Wawa Dam in Montalban , Rizal . The Wawa Dam which served Manila and surrounding locales had to be replaced due to the growing population of the Manila area. The La Mesa Dam

663-490: The earth-filled dam (also called an earthen dam or terrain dam ) made of compacted earth, and the rock-filled dam . A cross-section of an embankment dam shows a shape like a bank, or hill. Most have a central section or core composed of an impermeable material to stop water from seeping through the dam. The core can be of clay, concrete, or asphalt concrete . This type of dam is a good choice for sites with wide valleys. They can be built on hard rock or softer soils. For

702-484: The (DENR) and the Metropolitan Waterworks and Sewerage System (MWSS). The La Mesa Dam is part of the Angat - Ipo -La Mesa water system which supplies water to Metro Manila and surrounding provinces. The water collected in the reservoir is treated at the La Mesa and Balara Treatment Plants . The La Mesa facility has a designed capacity of 2,400 million litres per day (mld) and serves the western half of Metro Manila, while

741-686: The Balara facility has a capacity of 1,600 mld and handles the remaining eastern section. Whenever the dam’s water level drops below the critical mark of 69 meters (226 ft), the MWSS, Maynilad , and Manila Water begin regulating water dispensed to customers. Because the dam is designed to overflow into the Tullahan River, the locations affected by spills from the dam in cases of extreme weather are Fairview, Valenzuela, Navotas, Quezon City and Malabon. Earth dam Embankment dams come in two types:

780-403: The U.S. Bureau of Reclamation homogeneous Homogeneity and heterogeneity are concepts relating to the uniformity of a substance , process or image. A homogeneous feature is uniform in composition or character (i.e. color, shape, size, weight, height, distribution, texture, language, income, disease, temperature, radioactivity, architectural design, etc.); one that is heterogeneous

819-616: The asphalt make such dams especially suited to earthquake regions. For the Moglicë Hydro Power Plant in Albania the Norwegian power company Statkraft built an asphalt-core rock-fill dam. Upon completion in 2018 the 320 m long, 150 m high and 460 m wide dam is anticipated to be the world's highest of its kind. A concrete-face rock-fill dam (CFRD) is a rock-fill dam with concrete slabs on its upstream face. This design provides

SECTION 20

#1732855019319

858-411: The books" means that she read none of them. Neither sentence can be asserted if Robin read exactly half of the books. This is a puzzle because the negative sentence does not appear to be the classical negation of the sentence. A variety of explanations have been proposed including that natural language operates on a trivalent logic . With information technology , heterogeneous computing occurs in

897-536: The concrete slab as an impervious wall to prevent leakage and also a structure without concern for uplift pressure. In addition, the CFRD design is flexible for topography, faster to construct and less costly than earth-fill dams. The CFRD concept originated during the California Gold Rush in the 1860s when miners constructed rock-fill timber-face dams for sluice operations . The timber was later replaced by concrete as

936-406: The core is separated using a filter. Filters are specifically graded soil designed to prevent the migration of fine grain soil particles. When suitable building material is at hand, transport is minimized, leading to cost savings during construction. Rock-fill dams are resistant to damage from earthquakes . However, inadequate quality control during construction can lead to poor compaction and sand in

975-406: The dam must be calculated in advance of building to ensure that its break level threshold is not exceeded. Overtopping or overflow of an embankment dam beyond its spillway capacity will cause its eventual failure . The erosion of the dam's material by overtopping runoff will remove masses of material whose weight holds the dam in place and against the hydraulic forces acting to move the dam. Even

1014-486: The dam, but embankment dams are prone to seepage through the dam as well; for example, the Usoi landslide dam leaks 35-80 cubic meters per second. Sufficiently fast seepage can dislodge a dam's component particles, which results in faster seepage, which turns into a runaway feedback loop that can destroy the dam in a piping-type failure. Seepage monitoring is therefore an essential safety consideration. gn and Construction in

1053-452: The design was applied to irrigation and power schemes. As CFRD designs grew in height during the 1960s, the fill was compacted and the slab's horizontal and vertical joints were replaced with improved vertical joints. In the last few decades, design has become popular. The tallest CFRD in the world is the 233 m-tall (764 ft) Shuibuya Dam in China , completed in 2008. The building of

1092-566: The embankment which can lead to liquefaction of the rock-fill during an earthquake. Liquefaction potential can be reduced by keeping susceptible material from being saturated, and by providing adequate compaction during construction. An example of a rock-fill dam is New Melones Dam in California or the Fierza Dam in Albania . A core that is growing in popularity is asphalt concrete . The majority of such dams are built with rock and/or gravel as

1131-429: The last -e- (and the associated pronunciations) are common, but mistaken: homogenous is strictly a biological/pathological term which has largely been replaced by homologous . But use of homogenous to mean homogeneous has seen a rise since 2000, enough for it to now be considered an "established variant". Similarly, heterogenous is a spelling traditionally reserved to biology and pathology , referring to

1170-464: The latter would be a mixture of water, octane , and silicone grease . Heterogeneous solids, liquids, and gases may be made homogeneous by melting, stirring, or by allowing time to pass for diffusion to distribute the molecules evenly. For example, adding dye to water will create a heterogeneous solution at first, but will become homogeneous over time. Entropy allows for heterogeneous substances to become homogeneous over time. A heterogeneous mixture

1209-424: The primary fill. Almost 100 dams of this design have now been built worldwide since the first such dam was completed in 1962. All asphalt-concrete core dams built so far have an excellent performance record. The type of asphalt used is a viscoelastic - plastic material that can adjust to the movements and deformations imposed on the embankment as a whole, and to settlement of the foundation. The flexible properties of

La Mesa Dam and Reservoir - Misplaced Pages Continue

1248-575: The property of an object in the body having its origin outside the body. The concepts are the same to every level of complexity. From atoms to galaxies , plants , animals , humans , and other living organisms all share both a common or unique set of complexities. Hence, an element may be homogeneous on a larger scale, compared to being heterogeneous on a smaller scale. This is known as an effective medium approximation . Various disciplines understand heterogeneity , or being heterogeneous , in different ways. Environmental heterogeneity (EH)

1287-401: The reactants and products are in the same phase , while heterogeneous reactions have reactants in two or more phases. Reactions that take place on the surface of a catalyst of a different phase are also heterogeneous. A reaction between two gases or two miscible liquids is homogeneous. A reaction between a gas and a liquid, a gas and a solid or a liquid and a solid is heterogeneous. Earth is

1326-501: The reservoir begins to move the entire structure. The embankment, having almost no elastic strength, would begin to break into separate pieces, allowing the impounded reservoir water to flow between them, eroding and removing even more material as it passes through. In the final stages of failure, the remaining pieces of the embankment would offer almost no resistance to the flow of the water and continue to fracture into smaller and smaller sections of earth or rock until they disintegrate into

1365-594: The reservoir spills into the Tullahan River that passes Brgy. Nova Proper (commonly called Bayan) which transports the water to Manila Bay . The La Mesa Watershed Reservation which hosts the dam and reservoir is jointly administered, supervised, and controlled by the Department of Environment and Natural Resources of the Philippine national government and the is under the joint administration, supervision and control of

1404-399: The river bed and 95 sq mi (250 km ) reservoir make it the largest earth-filled dam in the world. The principal element of the project is an embankment 9,000 feet (2,700 m) long with a maximum height of 465 feet (142 m). The dam used approximately 200 million cubic yards (152.8 million cu. meters) of fill, which makes it one of the largest man-made structures in

1443-404: The upstream face and made of masonry , concrete , plastic membrane, steel sheet piles, timber or other material. The impervious zone may also be inside the embankment, in which case it is referred to as a "core". In the instances where clay is used as the impervious material, the dam is referred to as a "composite" dam. To prevent internal erosion of clay into the rock fill due to seepage forces,

1482-414: The world. Because earthen dams can be constructed from local materials, they can be cost-effective in regions where the cost of producing or bringing in concrete would be prohibitive. Rock -fill dams are embankments of compacted free-draining granular earth with an impervious zone. The earth used often contains a high percentage of large particles, hence the term "rock-fill". The impervious zone may be on

1521-521: Was built in Novaliches, which was then in the municipality of Caloocan due to the sloping topography of the watershed area from Bulacan. The dam later became part of a larger system with the opening of Ipo Dam in Norzagaray , Bulacan in 1936, and Angat Dam in the same locale in 1967. The La Mesa Dam was raised in 1959 to increase the reservoir's maximum capacity to its current level. The La Mesa Dam

#318681