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Hypolimnetic Aeration
Via deep water aeration or hypolimnetic aeration, the oxygen demand of deep water is provided by oxygen from the atmosphere without destroying the lake’s natural stratification. Thus the deep water becomes aerobic, the dissolving of phosphates is reduced significantly and the production of ammonia by sediments improves. Scientific evidence shows that it is possible to keep the deep water clean through this process all year round via technical ventilation measures and thereby to recover the natural balance of lakes effectively.Steinberg, C., Bernhardt, H.: Handbuch Angewandte Limnologie – 14. Erg.Lfg. 4/0 Verlag: Hüthig Jehle Rehm, 2002, . Eutrophication In stratified, eutrophic lakes an oxygen deficit in deep water is created during summer stagnation. As a result of elevated nutrient inputs, the trophic level of many lakes increases continuously. Elevated phosphorus concentrations may lead to stronger algae growth and a corresponding increase in oxygen consumption in the d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Aeration
Water aeration is the process of increasing or maintaining the oxygen saturation of water in both natural and artificial environments. Aeration techniques are commonly used in pond, lake, and reservoir management to address low oxygen levels or algal blooms. Water quality Water aeration is often required in water bodies that suffer from Hypoxia (environmental), hypoxic or anoxic conditions, often caused by upstream human activities such as sewage discharges, agricultural run-off, or over-baiting a fishing lake. Aeration can be achieved through the infusion of air into the bottom of the lake, lagoon or pond or by surface agitation from a fountain or spray-like device to allow for oxygen exchange at the surface and the release of gasses such as carbon dioxide, methane or hydrogen sulfide. Decreased levels of dissolved oxygen (DO) is a major contributor to poor water quality. Not only do fish and most other aquatic animals need oxygen, aerobic bacteria help decompose organic matter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper
Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals that can occur in nature in a directly usable metallic form ( native metals). This led to very early human use in several regions, from circa 8000 BC. Thousands of years later, it was the first metal to be smelted from sulfide ores, circa 5000 BC; the first metal to be cast into a shape in a mold, c. 4000 BC; and the first metal to be purposely alloyed with another metal, tin, to create ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galvanization
Galvanization or galvanizing (American and British English spelling differences, also spelled galvanisation or galvanising) is the process of applying a protective zinc coating to steel or iron, to prevent rusting. The most common method is hot-dip galvanization, hot-dip galvanizing, in which the parts are submerged in a bath of hot, molten zinc. Protective action The zinc coating, when intact, prevents corrosive substances from reaching the underlying iron. Additional electroplating such as a chromate conversion coating may be applied to provide further Passivation (chemistry)#Surface passivation, surface passivation to the substrate material. History and etymology The earliest known example of galvanized iron was encountered by Europeans on 17th-century Indian armour in the Royal Armouries Museum collection. The term "galvanized" continues to be used metaphorically of any stimulus which results in activity by a person or group of people. In modern usage, the term "galva ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corrosion
Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engineering is the field dedicated to controlling and preventing corrosion. In the most common use of the word, this means electrochemical oxidation of metal in reaction with an oxidant such as oxygen, hydrogen or hydroxide. Rusting, the formation of iron oxides, is a well-known example of electrochemical corrosion. This type of damage typically produces oxide(s) or salt(s) of the original metal and results in a distinctive orange colouration. Corrosion can also occur in materials other than metals, such as ceramics or polymers, although in this context, the term "degradation" is more common. Corrosion degrades the useful properties of materials and structures including strength, appearance and permeability to liquids and gases. Many structural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermocline
A thermocline (also known as the thermal layer or the metalimnion in lakes) is a thin but distinct layer in a large body of fluid (e.g. water, as in an ocean or lake; or air, e.g. an atmosphere) in which temperature changes more drastically with depth than it does in the layers above or below. In the ocean, the thermocline divides the upper mixed layer from the calm deep water below. Depending largely on season, latitude, and turbulent mixing by wind, thermoclines may be a semi-permanent feature of the body of water in which they occur, or they may form temporarily in response to phenomena such as the radiative heating/cooling of surface water during the day/night. Factors that affect the depth and thickness of a thermocline include seasonal weather variations, latitude, and local environmental conditions, such as tides and currents. Oceans Most of the heat energy of the sunlight that strikes the Earth is absorbed in the first few centimeters at the ocean's surface, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newman Lake
Newman Lake—historically and alternatively known as Moab—is an unincorporated community in Spokane County, Washington, United States. Newman Lake, which took its name from early settler William Newman, is east-northeast of downtown Spokane. Newman Lake has a post office with ZIP code 99025. It is also home to Ellerport Airport, a private-use airport. As of the summer of 2014, freshwater jellyfish inhabited the lake. The area was settled in the 1880s and served by the Northern Pacific Railway The Northern Pacific Railway was a transcontinental railroad that operated across the northern tier of the western United States, from Minnesota to the Pacific Northwest. It was approved by Congress in 1864 and given nearly of land grants, whic ..., which later ran excursion trains from Spokane. The local post office was renamed from Moab to Newman Lake in the 1930s. References External linksOriginal Newman Lake website [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aquatic Therapy
Aquatic therapy refers to treatments and exercises performed in water for relaxation, fitness, physical rehabilitation, and other therapeutic benefit. Typically a qualified aquatic therapist gives constant attendance to a person receiving treatment in a heated therapy pool. Aquatic therapy techniques include Ai Chi, Aqua Running, Bad Ragaz Ring Method, Burdenko Method, Halliwick, Watsu, and other aquatic bodywork forms. Therapeutic applications include neurological disorders, spine pain, musculoskeletal pain, postoperative orthopedic rehabilitation, pediatric disabilities, and pressure ulcers. Overview Aquatic therapy refers to water-based treatments or exercises of therapeutic intent, in particular for relaxation, fitness, and physical rehabilitation. Treatments and exercises are performed while floating, partially submerged, or fully submerged in water. Many aquatic therapy procedures require constant attendance by a trained therapist, and are performed in a speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waterbody Restoration
Stream restoration or river restoration, also sometimes referred to as river reclamation, is work conducted to improve the environmental health of a river or stream, in support of biodiversity, recreation, flood management and/or landscape development. Stream restoration approaches can be divided into two broad categories: form-based restoration, which relies on physical interventions in a stream to improve its conditions; and process-based restoration, which advocates the restoration of hydrological and geomorphological processes (such as sediment transport or connectivity between the channel and the floodplain) to ensure a stream's resilience and ecological health. Form-based restoration techniques include deflectors; cross-vanes; weirs, step-pools and other grade-control structures; engineered log jams; bank stabilization methods and other channel-reconfiguration efforts. These induce immediate change in a stream, but sometimes fail to achieve the desired effects if degradatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alloy
An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility, opacity (optics), opacity, and lustre (mineralogy), luster, but may have properties that differ from those of the pure metals, such as increased strength or hardness. In some cases, an alloy may reduce the overall cost of the material while preserving important properties. In other cases, the mixture imparts synergistic properties to the constituent metal elements such as corrosion resistance or mechanical strength. Alloys are defined by a metallic bonding character. The alloy constituents are usually measured by mass percentage for practical applications, and in Atomic ratio, atomic fraction for basic science studies. Alloys are usually classified as substitutional or interstitial alloys, depending on the atomic arrangement that forms the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stainless Steel
Stainless steel is an alloy of iron that is resistant to rusting and corrosion. It contains at least 11% chromium and may contain elements such as carbon, other nonmetals and metals to obtain other desired properties. Stainless steel's corrosion resistance, resistance to corrosion results from the chromium, which forms a Passivation (chemistry), passive film that can protect the material and self-healing material, self-heal in the presence of oxygen. The alloy's properties, such as luster and resistance to corrosion, are useful in many applications. Stainless steel can be rolled into Sheet metal, sheets, plates, bars, wire, and tubing. These can be used in cookware, cutlery, surgical instruments, major appliances, vehicles, construction material in large buildings, industrial equipment (e.g., in paper mills, chemical plants, water treatment), and storage tanks and tankers for chemicals and food products. The biological cleanability of stainless steel is superior to both alumi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polypropylene
Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications. It is produced via chain-growth polymerization from the monomer propylene. Polypropylene belongs to the group of polyolefins and is partially crystalline and non-polar. Its properties are similar to polyethylene, but it is slightly harder and more heat-resistant. It is a white, mechanically rugged material and has a high chemical resistance. Bio-PP is the bio-based counterpart of polypropylene (PP). Polypropylene is the second-most widely produced commodity plastic (after polyethylene). In 2019, the global market for polypropylene was worth $126.03 billion. Revenues are expected to exceed US$145 billion by 2019. The sales of this material are forecast to grow at a rate of 5.8% per year until 2021. History Phillips Petroleum chemists J. Paul Hogan and Robert Banks first demonstrated the polymerization of propylene in 1951. The stereoselective polymerization t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
