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How does a submerged arc furnace work?
A submerged arc furnace (SAF) operates by using electric arcs generated between electrodes that are submerged in a bed of raw materials, typically including metal ores, fluxes, and carbonaceous materials. The electric current passes through the materials, generating heat and causing them to melt and react chemically. This process allows for the efficient production of metals, particularly ferroalloys and silicon, as it can operate at high temperatures with a high degree of energy efficiency. The molten metal and slag are collected at the bottom of the furnace, while off-gases are managed for environmental compliance.
What do the particles look like in a liquid when it's evaporating?
he study focused on deposits formed under two conditions of two extremes of fluid flow; quiescent settling and deposition from turbulent flow. This work was to answer specific questions including: "What does the interface look like?"; "What are the transport mechanisms that determine rate of deposition and the structure of the interface?"; and "What are the kinetics of formation of various portions of the interface?". One premise of the work was that the morphology of the interface is intimately related to, and in some cases predictable from the characteristics of the suspended particles and the local fluid flow. This study yields critical information needed to calculate mass transport across the sediment/water "boundary", to interpret data obtained from sediment cores, to determine sampling protocols for sediments, and to assess sediment remediation schemes. Approach:This work combined models for particle transport and transformation to describe the formation of the sediment/water interface under conditions in which particle deposition rather than resuspension dominate the overall flux of particles to and from sediment. The work was compose of four interrelated tasks: 1) particle deposition under different conditions of fluid flow experiments performed using laboratory suspensions of particles of various sizes and surface chemistries; 2) similar experiments were conducted using sediment material collected from Galveston Bay or another source; 3) experimental results were compared with numerical simulations of the deposition process; and 4) to better define the chemistry of the colloidal and fineparticle phases that exist in Galveston Bay.Publications and Presentations:Publications have been submitted on this subproject: View all 7 publications for this subproject | View all 426 publications for this centerJournal Articles:Journal Articles have been submitted on this subproject: View all 4 journal articles for this subproject | View all 113 journal articles for this centerSupplemental Keywords:deposition, fluid flow, and suspended particles. , Ecosystem Protection/Environmental Exposure & Risk, Water, Scientific Discipline, Waste, RFA, Chemical Engineering, Analytical Chemistry, Hazardous Waste, Environmental Engineering, Fate & Transport, Environmental Chemistry, Contaminated Sediments, Hazardous, Ecology and Ecosystems, heavy metals, remediation, risk assessment, contaminant transport models, biodegradation, biotransformation, fate and transport, soil and groundwater remediation, aquifer fate and treatment, deposit morphology, technical outreach, chemical kinetics, contaminated sediment, anaerobic biotransformation, environmental technology, hazardous waste management, marine sediments, contaminated soil, bioremediation of soils, contaminated marine sediment, hazardous waste treatment, hydrology, sediment treatment, technology transfer, kinetics, chemical contaminantsProgress and Final Reports:Final ReportMain Center Abstract and Reports:R825513 HSRC (1989) - South and Southwest HSRCSubprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).R825513C001 Sediment Resuspension and Contaminant Transport in an Estuary.R825513C002 Contaminant Transport Across Cohesive Sediment Interfaces.R825513C003 Mobilization and Fate of Inorganic Contaminant due to Resuspension of Cohesive Sediment.R825513C004 Source Identification, Transformation, and Transport Processes of N-, O- and S- Containing Organic Chemicals in Wetland and Upland Sediments.R825513C005 Mobility and Transport of Radium from Sediment and Waste Pits.R825513C006 Anaerobic Biodegradation of 2,4,6-Trinitrotoluene and Other Nitroaromatic Compounds by Clostridium Acetobutylicum.R825513C007 Investigation on the Fate and Biotransformation of Hexachlorobutadiene and Chlorobenzenes in a Sediment-Water Estuarine SystemR825513C008 An Investigation of Chemical Transport from Contaminated Sediments through Porous Containment StructuresR825513C009 Evaluation of Placement and Effectiveness of Sediment CapsR825513C010 Coupled Biological and Physicochemical Bed-Sediment ProcessesR825513C011 Pollutant Fluxes to Aquatic Systems via Coupled Biological and Physicochemical Bed-Sediment ProcessesR825513C012 Controls on Metals Partitioning in Contaminated SedimentsR825513C013 Phytoremediation of TNT Contaminated Soil and GroundwatersR825513C014 Sediment-Based Remediation of Hazardous Substances at a Contaminated Military BaseR825513C015 Effect of Natural Dynamic Changes on Pollutant-Sediment InteractionR825513C016 Desorption of Nonpolar Organic Pollutants from Historically Contaminated Sediments and Dredged MaterialsR825513C017 Modeling Air Emissions of Organic Compounds from Contaminated Sediments and Dredged Materials title change in last year to "Long-term Release of Pollutants from Contaminated Sediment Dredged Material"R825513C018 Development of an Integrated Optic Interferometer for In-Situ Monitoring of Volatile HydrocarbonsR825513C019 Bioremediation of Contaminated Sediments and Dredged MaterialR825513C020 Bioremediation of Sediments Contaminated with Polyaromatic HydrocarbonsR825513C021 Role of Particles in Mobilizing Hazardous Chemicals in Urban RunoffR825513C022 Particle Transport and Deposit Morphology at the Sediment/Water InterfaceR825513C023 Uptake of Metal Ions from Aqueous Solutions by SedimentsR825513C024 Bioavailability of Desorption Resistant Hydrocarbons in Sediment-Water Systems.R825513C025 Interactive Roles of Microbial and Spartina Populations in Mercury Methylation Processes in Bioremediation of Contaminated Sediments in Salt-Marsh SystemsR825513C026 Evaluation of Physical-Chemical Methods for Rapid Assessment of the Bioavailability of Moderately Polar Compounds in SedimentsR825513C027 Freshwater Bioturbators in Riverine Sediments as Enhancers of Contaminant ReleaseR825513C028 Characterization of Laguna Madre Contaminated Sediments.R825513C029 The Role of Competitive Adsorption of Suspended Sediments in Determining Partitioning and Colloidal Stability.R825513C030 Remediation of TNT-Contaminated Soil by Cyanobacterial Mat.R825513C031 Experimental and Detailed Mathematical Modeling of Diffusion of Contaminants in FluidsR825513C033 Application of Biotechnology in Bioremediation of Contaminated SedimentsR825513C034 Characterization of PAH's Degrading Bacteria in Coastal SedimentsR825513C035 Dynamic Aspects of Metal Speciation in the Miami River Sediments in Relation to Particle Size Distribution of Chemical HeterogeneityTop of pageThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.
What is heat conduction?
in heat transfer, conduction (or heat conduction) is the transfer of heat energy by microscopic diffusion and collisions of particles or quasi-particles within a body due to atemperature gradient. The microscopically diffusing and colliding objects include molecules, electrons, atoms, and phonons. They transfer microscopically disorganized kinetic energy. Conduction takes place in all forms of ponderable matter, such as solids, liquids, gases and plasmas.By conduction, as well as by thermal radiation, heat spontaneously flows from a body at a higher temperature to a body at a lower temperature. In the absence of external driving fluxes, temperature differences, over time, approach thermal equilibrium.During conduction, the heat flows through the body itself, as opposed to its transfer by the bulk motion of the matter as in convection, and by thermal radiation. In solids, it is due to the combination of vibrations of the molecules in a lattice or phonons and diffusion of free electrons. In gases and liquids, conduction is due to the collisions and diffusion of the molecules during their random motion. Photons in this context do not collide with one another, and heat transport by electromagnetic radiation is conceptually distinct from heat conduction by microscopic diffusion and collisions of material particles and phonons. In condensed matter, such as a solid or liquid, the distinction between conduction and radiative transfer of heat is clear in physical concept, but it is often not phenomenologically clear, unless the material is semi-transparent. In a gas the distinction is both conceptually and phenomenologically clear.In the engineering sciences, heat transfer includes the processes of thermal radiation, convection, and sometimes mass transfer. Usually more than one of these processes occurs in a given situation. The conventional symbol for the material property, thermal conductivity, is .
The Basics of Welding Rods?
Welding rods are a crucial element of the welding process. In some circles, they are referred to as filler metals. For those who are unaware, a welding rod is a metal that is used during the welding process to connect to joints to one another either during repair manufacture of metal products. In most cases, the way that welding occurs is when the work pieces are partially melted and a filler metal, usually in the form of a welding rod, is used in order to form a liquid pool that joins the two parts together. When the metal solidifies, it creates a strong joint. A welding rode may also be referred to as an electrode. In most cases, they come in four different types. One of these types is the covered welding rod. The coating of the rod usually consists of calcium fluoride, iron powder, cellulose, and rutile. Rods that are coted in rutile typically give the weld a much nicer looking appearance that is very solid and high in quality. In some cases, a stainless steel rod may be used in order to weld two steel pieces together. In gas welding, bare welding rods are used instead. Several deoxidizing metals are included such as aluminum, silicon, titanium, and manganese. These are used in order to keep oxygen out of the process, which can cause the metals to rust and corrode during welding. Other materials such as titanium and zirconium may be included in order to prevent nitrogen from reacting with the metals as well. In most cases, these rods come with thicknesses somewhere between 2.4 and 0.7 millimeters. The thickness of the rod will depend on the metals that are being used, and for what purpose. A tubular welding rod, which comes in the form of a wire, is used in what is referred to as flux-cored arc welding. Another type of welding rod are the welding fluxes, which are used in submerged arc welding. This is a process that requires a constant supply of both solid and tubular welding rods. These four types of welding rods can be divided up into fast-fill electrodes and fast-freeze electrodes. Fast fill electrodes melt rapidly, while fast-freeze electrodes solidify quickly.
What does sola mean in science?
This article is about all uses of solar energy. For the journal, see Solar Energy Journal.Nellis Solar Power Plant in the United States, one of the largest photovoltaic power plants in North America.Renewable energyBiofuelBiomassGeothermalHydroelectricitySolar energyTidal powerWave powerWind powervteSolar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar energy technologies include solar heating, solar photovoltaics, solar thermal electricity and solar architecture, which can make considerable contributions to solving some of the most urgent problems the world now faces.[1]Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute solar energy. Active solar techniques include the use of photovoltaic panels and solar thermal collectors to harness the energy. Passive solar techniques include orienting a building to the Sun, selecting materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate air.In 2011, the International Energy Agency said that "the development of affordable, inexhaustible and clean solar energy technologies will have huge longer-term benefits. It will increase countries' energy security through reliance on an indigenous, inexhaustible and mostly import-independent resource, enhance sustainability, reduce pollution, lower the costs of mitigating climate change, and keep fossil fuel prices lower than otherwise. These advantages are global. Hence the additional costs of the incentives for early deployment should be considered learning investments; they must be wisely spent and need to be widely shared".[1]Contents[hide] 1 Energy from the Sun2 Applications of solar technology 2.1 Architecture and urban planning2.2 Agriculture and horticulture2.3 Solar lighting2.4 Solar thermal 2.4.1 Water heating2.4.2 Heating, cooling and ventilation2.4.3 Water treatment2.4.4 Cooking2.4.5 Process heat2.5 Solar power 2.5.1 Concentrated solar power2.5.2 Photovoltaics2.6 Solar chemical2.7 Solar vehicles3 Energy storage methods4 Development, deployment and economics5 ISO Standards6 See also7 Notes8 References9 External linksEnergy from the SunMain articles: Insolation and Solar radiation About half the incoming solar energy reaches the Earth's surface.The Earth receives 174 petawatts (PW) of incoming solar radiation (insolation) at the upper atmosphere.[2] Approximately 30% is reflected back to space while the rest is absorbed by clouds, oceans and land masses. The spectrum of solar light at the Earth's surface is mostly spread across the visible and near-infrared ranges with a small part in the near-ultraviolet.[3]Earth's land surface, oceans and atmosphere absorb solar radiation, and this raises their temperature. Warm air containing evaporated water from the oceans rises, causing atmospheric circulation or convection. When the air reaches a high altitude, where the temperature is low, water vapor condenses into clouds, which rain onto the Earth's surface, completing the water cycle. The latent heat of water condensation amplifies convection, producing atmospheric phenomena such as wind, cyclones and anti-cyclones.[4] Sunlight absorbed by the oceans and land masses keeps the surface at an average temperature of 14 °C.[5] By photosynthesis green plants convert solar energy into chemical energy, which produces food, wood and the biomass from which fossil fuels are derived.[6]Yearly Solar fluxes & Human Energy ConsumptionSolar3,850,000 EJ[7]Wind2,250 EJ[8]Biomass3,000 EJ[9]Primary energy use (2005)487 EJ[10]Electricity (2005)56.7 EJ[11]The total solar energy absorbed by Earth's atmosphere, oceans and land masses is approximately 3,850,000 exajoules (EJ) per year.[7] In 2002, this was more energy in one hour than the world used in one year.[12][13] Photosynthesis captures approximately 3,000 EJ per year in biomass.[9] The amount of solar energy reaching the surface of the planet is so vast that in one year it is about twice as much as will ever be obtained from all of the Earth's non-renewable resources of coal, oil, natural gas, and mined uranium combined.[14]Solar energy can be harnessed in different levels around the world. Depending on a geographical location the closer to the equator the more "potential" solar energy is available.[15]Applications of solar technologyAverage insolation showing land area (small black dots) required to replace the world primary energy supply with solar electricity. 18 TW is 568 Exajoule (EJ) per year. Insolation for most people is from 150 to 300 W/m2 or 3.5 to 7.0 kWh/m2/day. Solar energy refers primarily to the use of solar radiation for practical ends. However, all renewable energies, other than geothermal and tidal, derive their energy from the sun.Solar technologies are broadly characterized as either passive or active depending on the way they capture, convert and distribute sunlight. Active solar techniques use photovoltaic panels, pumps, and fans to convert sunlight into useful outputs. Passive solar techniques include selecting materials with favorable thermal properties, designing spaces that naturally circulate air, and referencing the position of a building to the Sun. Active solar technologies increase the supply of energy and are considered supply side technologies, while passive solar technologies reduce the need for alternate resources and are generally considered demand side technologies.[16]Architecture and urban planningMain articles: Passive solar building design and Urban heat island Darmstadt University of Technology in Germany won the 2007 Solar Decathlon in Washington, D.C. with this passive house designed specifically for the humid and hot subtropical climate.[17]Sunlight has influenced building design since the beginning of architectural history.[18] Advanced solar architecture and urban planning methods were first employed by the Greeks and Chinese, who oriented their buildings toward the south to provide light and warmth.[19]The common features of passive solar architecture are orientation relative to the Sun, compact proportion (a low surface area to volume ratio), selective shading (overhangs) and thermal mass.[18] When these features are tailored to the local climate and environment they can produce well-lit spaces that stay in a comfortable temperature range. Socrates' Megaron House is a classic example of passive solar design.[18] The most recent approaches to solar design use computer modeling tying together solar lighting, heating and ventilation systems in an integrated solar design package.[20] Active solar equipment such as pumps, fans and switchable windows can complement passive design and improve system performance.Urban heat islands (UHI) are metropolitan areas with higher temperatures than that of the surrounding environment. The higher temperatures are a result of increased absorption of the Solar light by urban materials such as asphalt and concrete, which have lower albedos and higher heat capacities than those in the natural environment. A straightforward method of counteracting the UHI effect is to paint buildings and roads white and plant trees. Using these methods, a hypothetical "cool communities" program in Los Angeles has projected that urban temperatures could be reduced by approximately 3 °C at an estimated cost of US$1 billion, giving estimated total annual benefits of US$530 million from reduced air-conditioning costs and healthcare savings.[21]Agriculture and horticultureGreenhouses like these in the Westland municipality of the Netherlands grow vegetables, fruits and flowers. Agriculture and horticulture seek to optimize the capture of solar energy in order to optimize the productivity of plants. Techniques such as timed planting cycles, tailored row orientation, staggered heights between rows and the mixing of plant varieties can improve crop yields.[22][23] While sunlight is generally considered a plentiful resource, the exceptions highlight the importance of solar energy to agriculture. During the short growing seasons of the Little Ice Age, French and English farmers employed fruit walls to maximize the collection of solar energy. These walls acted as thermal masses and accelerated ripening by keeping plants warm. Early fruit walls were built perpendicular to the ground and facing south, but over time, sloping walls were developed to make better use of sunlight. In 1699, Nicolas Fatio de Duillier even suggested using a tracking mechanism which could pivot to follow the Sun.[24] Applications of solar energy in agriculture aside from growing crops include pumping water, drying crops, brooding chicks and drying chicken manure.[25][26] More recently the technology has been embraced by vinters, who use the energy generated by solar panels to power grape presses.[27]Greenhouses convert solar light to heat, enabling year-round production and the growth (in enclosed environments) of specialty crops and other plants not naturally suited to the local climate. Primitive greenhouses were first used during Roman times to produce cucumbers year-round for the Roman emperor Tiberius.[28] The first modern greenhouses were built in Europe in the 16th century to keep exotic plants brought back from explorations abroad.[29] Greenhouses remain an important part of horticulture today, and plastic transparent materials have also been used to similar effect in polytunnels and row covers.Solar lightingDaylighting features such as this oculus at the top of the Pantheon, in Rome, Italy have been in use since antiquity. The history of lighting is dominated by the use of natural light. The Romans recognized a right to light as early as the 6th century and English law echoed these judgments with the Prescription Act of 1832.[30][31] In the 20th century artificial lighting became the main source of interior illumination but daylighting techniques and hybrid solar lighting solutions are ways to reduce energy consumption.Daylighting systems collect and distribute sunlight to provide interior illumination. This passive technology directly offsets energy use by replacing artificial lighting, and indirectly offsets non-solar energy use by reducing the need for air-conditioning.[32] Although difficult to quantify, the use of natural lighting also offers physiological and psychological benefits compared to artificial lighting.[32] Daylighting design implies careful selection of window types, sizes and orientation; exterior shading devices may be considered as well. Individual features include sawtooth roofs, clerestory windows, light shelves, skylights and light tubes. They may be incorporated into existing structures, but are most effective when integrated into a solar design package that accounts for factors such as glare, heat flux and time-of-use. When daylighting features are properly implemented they can reduce lighting-related energy requirements by 25%.[33]Hybrid solar lighting is an active solar method of providing interior illumination. HSL systems collect sunlight using focusing mirrors that track the Sun and use optical fibers to transmit it inside the building to supplement conventional lighting. In single-story applications these systems are able to transmit 50% of the direct sunlight received.[34]Solar lights that charge during the day and light up at dusk are a common sight along walkways.[35] Solar-charged lanterns have become popular in developing countries where they provide a safer and cheaper alternative to kerosene lamps.[36]Although daylight saving time is promoted as a way to use sunlight to save energy, recent research has been limited and reports contradictory results: several studies report savings, but just as many suggest no effect or even a net loss, particularly when gasoline consumption is taken into account. Electricity use is greatly affected by geography, climate and economics, making it hard to generalize from single studies.[37]Solar thermalMain article: Solar thermal energy Solar thermal technologies can be used for water heating, space heating, space cooling and process heat generation.[38]Water heatingMain articles: Solar hot water and Solar combisystem Solar water heaters facing the Sun to maximize gain.Solar hot water systems use sunlight to heat water. In low geographical latitudes (below 40 degrees) from 60 to 70% of the domestic hot water use with temperatures up to 60 °C can be provided by solar heating systems.[39] The most common types of solar water heaters are evacuated tube collectors (44%) and glazed flat plate collectors (34%) generally used for domestic hot water; and unglazed plastic collectors (21%) used mainly to heat swimming pools.[40]As of 2007, the total installed capacity of solar hot water systems is approximately 154 GW.[41] China is the world leader in their deployment with 70 GW installed as of 2006 and a long term goal of 210 GW by 2020.[42] Israel and Cyprus are the per capita leaders in the use of solar hot water systems with over 90% of homes using them.[43] In the United States, Canada and Australia heating swimming pools is the dominant application of solar hot water with an installed capacity of 18 GW as of 2005.[16]Heating, cooling and ventilationMain articles: Solar heating, Thermal mass, Solar chimney, and Solar air conditioning Solar House #1 of Massachusetts Institute of Technology in the United States, built in 1939, used seasonal thermal storage for year-round heating.In the United States, heating, ventilation and air conditioning (HVAC) systems account for 30% (4.65 EJ) of the energy used in commercial buildings and nearly 50% (10.1 EJ) of the energy used in residential buildings.[33][44] Solar heating, cooling and ventilation technologies can be used to offset a portion of this energy.Thermal mass is any material that can be used to store heat-heat from the Sun in the case of solar energy. Common thermal mass materials include stone, cement and water. Historically they have been used in arid climates or warm temperate regions to keep buildings cool by absorbing solar energy during the day and radiating stored heat to the cooler atmosphere at night. However they can be used in cold temperate areas to maintain warmth as well. The size and placement of thermal mass depend on several factors such as climate, daylighting and shading conditions. When properly incorporated, thermal mass maintains space temperatures in a comfortable range and reduces the need for auxiliary heating and cooling equipment.[45]A solar chimney (or thermal chimney, in this context) is a passive solar ventilation system composed of a vertical shaft connecting the interior and exterior of a building. As the chimney warms, the air inside is heated causing an updraft that pulls air through the building. Performance can be improved by using glazing and thermal mass materials[46] in a way that mimics greenhouses.Deciduous trees and plants have been promoted as a means of controlling solar heating and cooling. When planted on the southern side of a building, their leaves provide shade during the summer, while the bare limbs allow light to pass during the winter.[47] Since bare, leafless trees shade 1/3 to 1/2 of incident solar radiation, there is a balance between the benefits of summer shading and the corresponding loss of winter heating.[48] In climates with significant heating loads, deciduous trees should not be planted on the southern side of a building because they will interfere with winter solar availability. They can, however, be used on the east and west sides to provide a degree of summer shading without appreciably affecting winter solar gain.[49]Water treatmentMain articles: Solar still, Solar water disinfection, Solar desalination, and Solar Powered Desalination Unit Solar water disinfection in IndonesiaSmall scale solar powered sewerage treatment plant.Solar distillation can be used to make saline or brackish water potable. The first recorded instance of this was by 16th century Arab alchemists.[50] A large-scale solar distillation project was first constructed in 1872 in the Chilean mining town of Las Salinas.[51] The plant, which had solar collection area of 4,700 m2, could produce up to 22,700 L per day and operated for 40 years.[51] Individual still designs include single-slope, double-slope (or greenhouse type), vertical, conical, inverted absorber, multi-wick, and multiple effect.[50] These stills can operate in passive, active, or hybrid modes. Double-slope stills are the most economical for decentralized domestic purposes, while active multiple effect units are more suitable for large-scale applications.[50]Solar water disinfection (SODIS) involves exposing water-filled plastic polyethylene terephthalate (PET) bottles to sunlight for several hours.[52] Exposure times vary depending on weather and climate from a minimum of six hours to two days during fully overcast conditions.[53] It is recommended by the World Health Organization as a viable method for household water treatment and safe storage.[54] Over two million people in developing countries use this method for their daily drinking water.[53]Solar energy may be used in a water stabilisation pond to treat waste water without chemicals or electricity. A further environmental advantage is that algae grow in such ponds and consume carbon dioxide in photosynthesis, although algae may produce toxic chemicals that make the water unusable.[55][56]CookingMain article: Solar cooker The Solar Bowl in Auroville, India, concentrates sunlight on a movable receiver to produce steam for cooking.Solar cookers use sunlight for cooking, drying and pasteurization. They can be grouped into three broad categories: box cookers, panel cookers and reflector cookers.[57] The simplest solar cooker is the box cooker first built by Horace de Saussure in 1767.[58] A basic box cooker consists of an insulated container with a transparent lid. It can be used effectively with partially overcast skies and will typically reach temperatures of 90-150 °C.[59] Panel cookers use a reflective panel to direct sunlight onto an insulated container and reach temperatures comparable to box cookers. Reflector cookers use various concentrating geometries (dish, trough, Fresnel mirrors) to focus light on a cooking container. These cookers reach temperatures of 315 °C and above but require direct light to function properly and must be repositioned to track the Sun.[60]The solar bowl is a concentrating technology employed by the Solar Kitchen in Auroville, Pondicherry, India, where a stationary spherical reflector focuses light along a line perpendicular to the sphere's interior surface, and a computer control system moves the receiver to intersect this line. Steam is produced in the receiver at temperatures reaching 150 °C and then used for process heat in the kitchen.[61]A reflector developed by Wolfgang Scheffler in 1986 is used in many solar kitchens. Scheffler reflectors are flexible parabolic dishes that combine aspects of trough and power tower concentrators. Polar tracking is used to follow the Sun's daily course and the curvature of the reflector is adjusted for seasonal variations in the incident angle of sunlight. These reflectors can reach temperatures of 450-650 °C and have a fixed focal point, which simplifies cooking.[62] The world's largest Scheffler reflector system in Abu Road, Rajasthan, India is capable of cooking up to 35,000 meals a day.[63] As of 2008, over 2,000 large Scheffler cookers had been built worldwide.[64]Process heatMain articles: Solar pond, Salt evaporation pond, and Solar furnace Solar concentrating technologies such as parabolic dish, trough and Scheffler reflectors can provide process heat for commercial and industrial applications. The first commercial system was the Solar Total Energy Project (STEP) in Shenandoah, Georgia, USA where a field of 114 parabolic dishes provided 50% of the process heating, air conditioning and electrical requirements for a clothing factory. This grid-connected cogeneration system provided 400 kW of electricity plus thermal energy in the form of 401 kW steam and 468 kW chilled water, and had a one hour peak load thermal storage.[65]Evaporation ponds are shallow pools that concentrate dissolved solids through evaporation. The use of evaporation ponds to obtain salt from sea water is one of the oldest applications of solar energy. Modern uses include concentrating brine solutions used in leach mining and removing dissolved solids from waste streams.[66]Clothes lines, clotheshorses, and clothes racks dry clothes through evaporation by wind and sunlight without consuming electricity or gas. In some states of the United States legislation protects the "right to dry" clothes.[67]Unglazed transpired collectors (UTC) are perforated sun-facing walls used for preheating ventilation air. UTCs can raise the incoming air temperature up to 22 °C and deliver outlet temperatures of 45-60 °C.[68] The short payback period of transpired collectors (3 to 12 years) makes them a more cost-effective alternative than glazed collection systems.[68] As of 2003, over 80 systems with a combined collector area of 35,000 m2 had been installed worldwide, including an 860 m2 collector in Costa Rica used for drying coffee beans and a 1,300 m2 collector in Coimbatore, India used for drying marigolds.[26]Solar powerMain article: Solar power The PS10 concentrates sunlight from a field of heliostats on a central tower.Solar power is the conversion of sunlight into electricity, either directly using photovoltaics (PV), or indirectly using concentrated solar power (CSP). CSP systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. PV converts light into electric current using the photoelectric effect.Commercial CSP plants were first developed in the 1980s. Since 1985 the eventually 354 MW SEGS CSP installation, in the Mojave Desert of California, is the largest solar power plant in the world. Other large CSP plants include the Solnova Solar Power Station (150 MW) and the Andasol solar power station (100 MW), both in Spain. The Agua Caliente Solar Project, in the United States, and the 214 MW Charanka Solar Park in India, are the world's largest photovoltaic plants.Concentrated solar powerSee also: Concentrated solar power Concentrating Solar Power (CSP) systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. The concentrated heat is then used as a heat source for a conventional power plant. A wide range of concentrating technologies exists; the most developed are the parabolic trough, the concentrating linear fresnel reflector, the Stirling dish and the solar power tower. Various techniques are used to track the Sun and focus light. In all of these systems a working fluid is heated by the concentrated sunlight, and is then used for power generation or energy storage.[69]Photovoltaics80 MW Okhotnykovo Solar Park in Ukraine. NREL compilation of best research solar cell efficiencies from 1976 to 2012Main article: PhotovoltaicsA solar cell, or photovoltaic cell (PV), is a device that converts light into electric current using the photoelectric effect. The first solar cell was constructed by Charles Fritts in the 1880s.[70] In 1931 a German engineer, Dr Bruno Lange, developed a photo cell using silver selenide in place of copper oxide.[71] Although the prototype selenium cells converted less than 1% of incident light into electricity, both Ernst Werner von Siemens and James Clerk Maxwell recognized the importance of this discovery.[72] Following the work of Russell Ohl in the 1940s, researchers Gerald Pearson, Calvin Fuller and Daryl Chapin created the silicon solar cell in 1954.[73] These early solar cells cost 286 USD/watt and reached efficiencies of 4.5-6%.[74]Solar chemicalMain article: Solar chemical Solar chemical processes use solar energy to drive chemical reactions. These processes offset energy that would otherwise come from a fossil fuel source and can also convert solar energy into storable and transportable fuels. Solar induced chemical reactions can be divided into thermochemical or photochemical.[75] A variety of fuels can be produced by artificial photosynthesis.[76] The multielectron catalytic chemistry involved in making carbon-based fuels (such as methanol) from reduction of carbon dioxide is challenging; a feasible alternative is hydrogen production from protons, though use of water as the source of electrons (as plants do) requires mastering the multielectron oxidation of two water molecules to molecular oxygen.[77] Some have envisaged working solar fuel plants in coastal metropolitan areas by 2050- the splitting of sea water providing hydrogen to be run through adjacent fuel-cell electric power plants and the pure water by-product going directly into the municipal water system.[78]Hydrogen production technologies been a significant area of solar chemical research since the 1970s. Aside from electrolysis driven by photovoltaic or photochemical cells, several thermochemical processes have also been explored. One such route uses concentrators to split water into oxygen and hydrogen at high temperatures (2300-2600 °C).[79] Another approach uses the heat from solar concentrators to drive the steam reformation of natural gas thereby increasing the overall hydrogen yield compared to conventional reforming methods.[80] Thermochemical cycles characterized by the decomposition and regeneration of reactants present another avenue for hydrogen production. The Solzinc process under development at the Weizmann Institute uses a 1 MW solar furnace to decompose zinc oxide (ZnO) at temperatures above 1200 °C. This initial reaction produces pure zinc, which can subsequently be reacted with water to produce hydrogen.[81]Solar vehiclesMain articles: Solar vehicle, Solar-charged vehicle, Electric boat, and Solar balloon Australia hosts the World Solar Challenge where solar cars like the Nuna3 race through a 3,021 km (1,877 mi) course from Darwin to Adelaide.Development of a solar powered car has been an engineering goal since the 1980s. The World Solar Challenge is a biannual solar-powered car race, where teams from universities and enterprises compete over 3,021 kilometres (1,877 mi) across central Australia from Darwin to Adelaide. In 1987, when it was founded, the winner's average speed was 67 kilometres per hour (42 mph) and by 2007 the winner's average speed had improved to 90.87 kilometres per hour (56.46 mph).[82] The North American Solar Challenge and the planned South African Solar Challenge are comparable competitions that reflect an international interest in the engineering and development of solar powered vehicles.[83][84]Some vehicles use solar panels for auxiliary power, such as for air conditioning, to keep the interior cool, thus reducing fuel consumption.[85][86]In 1975, the first practical solar boat was constructed in England.[87] By 1995, passenger boats incorporating PV panels began appearing and are now used extensively.[88] In 1996, Kenichi Horie made the first solar powered crossing of the Pacific Ocean, and the sun21 catamaran made the first solar powered crossing of the Atlantic Ocean in the winter of 2006-2007.[89] There are plans to circumnavigate the globe in 2010.[90]Helios UAV in solar powered flight.In 1974, the unmanned AstroFlight Sunrise plane made the first solar flight. On 29 April 1979, the Solar Riser made the first flight in a solar powered, fully controlled, man carrying flying machine, reaching an altitude of 40 feet (12 m). In 1980, the Gossamer Penguin made the first piloted flights powered solely by photovoltaics. This was quickly followed by the Solar Challenger which crossed the English Channel in July 1981. In 1990 Eric Scott Raymond in 21 hops flew from California to North Carolina using solar power.[91] Developments then turned back to unmanned aerial vehicles (UAV) with the Pathfinder (1997) and subsequent designs, culminating in the Helios which set the altitude record for a non-rocket-propelled aircraft at 29,524 metres (96,864 ft) in 2001.[92] The Zephyr, developed by BAE Systems, is the latest in a line of record-breaking solar aircraft, making a 54-hour flight in 2007, and month-long flights are envisioned by 2010.[93]A solar balloon is a black balloon that is filled with ordinary air. As sunlight shines on the balloon, the air inside is heated and expands causing an upward buoyancy force, much like an artificially heated hot air balloon. Some solar balloons are large enough for human flight, but usage is generally limited to the toy market as the surface-area to payload-weight ratio is relatively high.[94]Energy storage methodsMain articles: Thermal mass, Thermal energy storage, Phase change material, Grid energy storage, and V2G Solar Two's thermal storage system generated electricity during cloudy weather and at night.Solar energy is not available at night, and energy storage is an important issue because modern energy systems usually assume continuous availability of energy.[95]Thermal mass systems can store solar energy in the form of heat at domestically useful temperatures for daily or seasonal durations. Thermal storage systems generally use readily available materials with high specific heat capacities such as water, earth and stone. Well-designed systems can lower peak demand, shift time-of-use to off-peak hours and reduce overall heating and cooling requirements.[96][97]Phase change materials such as paraffin wax and Glauber's salt are another thermal storage media. These materials are inexpensive, readily available, and can deliver domestically useful temperatures (approximately 64 °C). The "Dover House" (in Dover, Massachusetts) was the first to use a Glauber's salt heating system, in 1948.[98]Solar energy can be stored at high temperatures using molten salts. Salts are an effective storage medium because they are low-cost, have a high specific heat capacity and can deliver heat at temperatures compatible with conventional power systems. The Solar Two used this method of energy storage, allowing it to store 1.44 TJ in its 68 m3 storage tank with an annual storage efficiency of about 99%.[99]Off-grid PV systems have traditionally used rechargeable batteries to store excess electricity. With grid-tied systems, excess electricity can be sent to the transmission grid, while standard grid electricity can be used to meet shortfalls. Net metering programs give household systems a credit for any electricity they deliver to the grid. This is often legally handled by 'rolling back' the meter whenever the home produces more electricity than it consumes. If the net electricity use is below zero, the utility is required to pay for the extra at the same rate as they charge consumers.[100] Other legal approaches involve the use of two meters, to measure electricity consumed vs. electricity produced. This is less common due to the increased installation cost of the second meter.Pumped-storage hydroelectricity stores energy in the form of water pumped when energy is available from a lower elevation reservoir to a higher elevation one. The energy is recovered when demand is high by releasing the water to run through a hydroelectric power generator.[101]Development, deployment and economicsMain article: Deployment of solar power to energy grids See also: Cost of electricity by sourceBeginning with the surge in coal use which accompanied the Industrial Revolution, energy consumption has steadily transitioned from wood and biomass to fossil fuels. The early development of solar technologies starting in the 1860s was driven by an expectation that coal would soon become scarce. However development of solar technologies stagnated in the early 20th century in the face of the increasing availability, economy, and utility of coal and petroleum.[102]The 1973 oil embargo and 1979 energy crisis caused a reorganization of energy policies around the world and brought renewed attention to developing solar technologies.[103][104] Deployment strategies focused on incentive programs such as the Federal Photovoltaic Utilization Program in the US and the Sunshine Program in Japan. Other efforts included the formation of research facilities in the US (SERI, now NREL), Japan (NEDO), and Germany (Fraunhofer Institute for Solar Energy Systems ISE).[105]Commercial solar water heaters began appearing in the United States in the 1890s.[106] These systems saw increasing use until the 1920s but were gradually replaced by cheaper and more reliable heating fuels.[107] As with photovoltaics, solar water heating attracted renewed attention as a result of the oil crises in the 1970s but interest subsided in the 1980s due to falling petroleum prices. Development in the solar water heating sector progressed steadily throughout the 1990s and growth rates have averaged 20% per year since 1999.[41] Although generally underestimated, solar water heating and cooling is by far the most widely deployed solar technology with an estimated capacity of 154 GW as of 2007.[41]The International Energy Agency has said that solar energy can make considerable contributions to solving some of the most urgent problems the world now faces:[1]The development of affordable, inexhaustible and clean solar energy technologies will have huge longer-term benefits. It will increase countries' energy security through reliance on an indigenous, inexhaustible and mostly import-independent resource, enhance sustainability, reduce pollution, lower the costs of mitigating climate change, and keep fossil fuel prices lower than otherwise. These advantages are global. Hence the additional costs of the incentives for early deployment should be considered learning investments; they must be wisely spent and need to be widely shared.[1]In 2011, the International Energy Agency said that solar energy technologies such as photovoltaic panels, solar water heaters and power stations built with mirrors could provide a third of the world's energy by 2060 if politicians commit to limiting climate change. The energy from the sun could play a key role in de-carbonizing the global economy alongside improvements in energy efficiency and imposing costs on greenhouse gas emitters. "The strength of solar is the incredible variety and flexibility of applications, from small scale to big scale".[108]We have proved ... that after our stores of oil and coal are exhausted the human race can receive unlimited power from the rays of the sun.-Frank Shuman, New York Times, July 2, 1916[109]ISO StandardsThe International Organization for Standardization has established a number of standards relating to solar energy equipment. For example, ISO 9050 relates to glass in building while ISO 10217 relates to the materials used in solar water heaters. See alsoRenewable energy portalSustainable development portalEnergy portalAirmassCommunity solar farmDesertecEnergy storageGlobal dimmingGreasestockGreen electricityHeliostat
Are soldering and brazing fluxes the same?
No, soldering and brazing fluxes are not the same. Soldering fluxes are designed to remove oxides from the metal surfaces being joined during soldering, while brazing fluxes are formulated to clean the joint and promote wetting for the filler metal in brazing processes. Additionally, brazing fluxes can handle higher temperatures compared to soldering fluxes.
What are the ratings and certificates for Fluxes - 1969?
Fluxes - 1969 is rated/received certificates of: Singapore:PG
What is the plural of flux?
Fluxes
What are the release dates for Fluxes - 1969?
Fluxes - 1969 was released on: USA: October 1969 (Chicago International Film Festival)
Do all fluxes give off fumes that may be toxic?
No, not all fluxes give off toxic fumes. Some fluxes are specifically formulated to be low fuming or fume-free, making them safer to use. It's important to always check the product safety data sheet and use proper ventilation when working with fluxes to minimize exposure to any potential toxins.
What type of hazard is fluxes?
Fluxes can refer to various types of hazards depending on the context, but in environmental science, they often relate to the flow of energy or materials, such as nutrients or pollutants, within ecosystems. These fluxes can pose hazards when they lead to imbalances or contamination that negatively impact health, biodiversity, or ecosystem stability. For example, nutrient fluxes can cause algal blooms in water bodies, leading to hypoxia and harm to aquatic life. In summary, fluxes can represent environmental hazards when they disrupt natural processes or lead to pollution.
Can welding fluxes affect the penetration and contour of the weld bead?
Yes, welding fluxes can significantly affect the penetration and contour of the weld bead. Fluxes help stabilize the arc and protect the molten metal from oxidation, which can enhance penetration. Additionally, different types of fluxes can influence the fluidity of the weld pool, affecting the bead's shape and contour. Proper selection and application of flux are crucial for achieving desired weld characteristics.
What Fluxes are needed for melting brass?
Lemeltic degassing flux
What is a composition of fluxes and silica fused to make glass?
Frit
What is the partly fused sand and fluxes of which glass is made?
Frit
What is induction type relay?
An induction relay works only with alternating current. It consists of an electromagnetic system which operates on a moving conductor, generally in the form of a disc or cup, and functions through the interaction of electromagnetic fluxes with the parasitic Fault currents which are induced in the rotor by these fluxes. These two fluxes, which are mutually displaced both in angle and in position, produce a torque that can be expressed by T= Κ1.Φ1.Φ2 .sin θ, Where Φ1 and Φ2 are the interacting fluxes and θ is the phase angle between Φ1 and Φ2. It should be noted that the torque is a maximum when the fluxes are out of phase by 90º, and zero when they are in phase.
What is acidic fluxes?
Acidic fluxes are materials used in soldering and welding to remove oxides from the surfaces being joined. They work by breaking down the oxide layer on the metal, allowing for better wetting and bonding of the solder or welding filler material. However, acidic fluxes can be corrosive and may require thorough cleaning after use to prevent long-term damage to the joint.
