This biography of a living person does not cite any references or sources. Please help by adding reliable sources. Contentious material about living people that is unsourced or poorly sourced must be removed immediately. (June 2009)
Jane McGarrigle is a Canadian songwriter and musician.
She is the sister of Kate and Anna McGarrigle, and has written and performed several songs with the duo. She also composed the scores to the Canadian film Tommy Tricker and the Stamp Traveller and its sequel, The Return of Tommy Tricker.
This article on a Canadian musician is a stub. You can help Wikipedia by expanding it. v•d•e
Retrieved from “http://en.wikipedia.org/wiki/Jane_McGarrigle”
Categories: Canadian songwriters | Canadian composers | People from Montreal | Canadians of Irish descent | Irish Canadians | Living people | Canadian musician stubsHidden categories: Unreferenced BLPs from June 2009 | All unreferenced BLPs
This article needs additional citations for verification.
Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (July 2007)
Lock On: Modern Air Combat
Developer(s)
Eagle Dynamics
Publisher(s)
EU Ubisoft RUS 1C Company
Release date(s)
EU November 20, 2003 RUS November 21, 2003
Genre(s)
Flight simulator
System requirements
System: Pentium IV 1.6Ghz or AMD Athlon 1500+ or equivalent.
512 MB of RAM, 128 MB of Video Memory, 1.5 Gb of Hard Drive Space.
Input methods
Joystick, Mouse, Keyboard
Lock On: Modern Air Combat or LOMAC, known in Russia as Lock On, is a modern combat flight simulation developed by Eagle Dynamics and published by Ubisoft in Europe and 1C Company in Russia; widely regarded as one of the most realistic simulators in its class. It contains 8 flyable aircraft and over 40 non-playable/AI-controlled planes. The game mainly revolves around air-to-air combat and air-to-ground combat with some optional, unique roles such as pinpoint/anti-radiation strikes, anti-ship strikes or aerobatics. The game realistically models all aspects of take-off and landing, AWACS (also known as AEW&C), carrier-based landings (for the Su-33), and Aerial refueling.
Over 180,000 buildings, 50 million trees, 21 cities, 1,700 towns, 500 bridges, 18 airfields, and 8 naval bases are present in a virtual world modelled after Black Sea region. The 8 flyable aircraft are the MiG-29A, MiG-29C , Su-27, Su-33, Su-25, MiG-29G (a German MiG-29 variant with a native board-computer), F-15C, and the A-10A; only the Su-25 and A-10 are dedicated close air support aircraft, the rest are air superiority or multi-role fighters with limited or no air-to-ground capabilities. Due to the small number of aircraft the player can only fly as a pilot from either the United States, Ukraine, the Russian Federation, Georgia, Israel or Germany.
A flexible mission editor is included to allow users to make a wide variety of missions or even full-length campaigns, equal to the quality of those presented with the game. Many fan created mission packs and campaigns have also been released: .
In-game screenshot of the MiG-29S.
Contents
1Upgrades
2Flaming Cliffs 2.0
3Bill & John
4References
5External links
Upgrades
View of the Su-27 cockpit in Lock On.
Aside from the v1.02 patch for the retail game the developer, Eagle Dynamics, has released an unofficial add-on named Lock On: Flaming Cliffs, designed in part to correct numerous flaws within the original game. Also included is another flyable aircraft, the Su-25T and several new missions. Some changes and tweaks to the games missile modeling are also included, as is an Advanced Flight Model (AFM) for the Su-25T. A patch to Flaming Cliffs was released, correcting minor coding errors and bringing the game to its final, current version: 1.12b.
Flaming Cliffs 2.0
In November 2009 Eagle Dynamics announced that a pay-for upgrade ($14.99 USD) called Flaming Cliffs 2.0 was planned for release in early 2010. Improvements include:
Forward compatibility as well as online compatibility with the new Eagle Dynamics title DCS: Black Shark. Players may fly Flaming Cliffs-specific aircraft in missions/campaigns created for DCS:Black Shark (and vice versa) and in multi-player games with players running DCS:Black Shark online.
General improvements and bug fixes to the the multi-player component of Flaming Cliffs.
Features the same virtual world environment as DCS:Black Shark (the Crimean portion of the previous Flaming Cliffs map has been removed while additional areas of Georgia have been introduced, modelled at higher resolutions than in DCS: Black Shark).
Automatic detection of player-modified configuration files when connecting to a multi-player server.
Updated graphics engines (referred to as The Fighter Collection Simulation Engine (TFCSE)) running natively under DirectX 9.0c with numerous improvements to texture, weather and resolution quality.
Improved and more realistic aircraft, weaponry, sensory and audio modelling.
Brand-new Mission Editor with scriptable triggers, new mission roles and improved AI/flight modelling for NPC aircraft.
Lock On: Modern Air Combat is the source of the video of the awards-winning machinimaThe Adventures of Bill & John.
References
^ ab http://games.1c.ru/lock_on/
^ ab http://www.mobygames.com/game/windows/lock-on-modern-air-combat/release-info
External links
Official game site
Add On & Forums site
Serbian Lock On Community Serbian Eagles
LOMAC : FC =TuAF= Squadron formed by Turkish virtual pilots
Croatian Lock On Support
Preflight, an Israeli simulation fan site with an active Lock On community
Official Flaming Cliffs 2.0 announcement, announcement of Lock On: Flaming Cliffs 2.0
104th-Phoenix: Lock-On & Black Bhark Community and Squadron site
51 PVO Regiment
v•d•e
Flanker series
Titles:
Su-27 Flanker · Su-27 Flanker: Squadron Commander’s Edition · Flanker 2.0 · Flanker 2.5 · Lock On: Modern Air Combat
Related aircraft:
A-10 · F-15 · MiG-29 · Su-25 · Su-27 · Su-33
Retrieved from “http://en.wikipedia.org/wiki/Lock_On:_Modern_Air_Combat”
Categories: 2003 video games | Combat flight simulators | Windows games | Video games developed in Russia | Lua-scripted video gamesHidden categories: Articles needing additional references from July 2007 | All articles needing additional references | All articles with unsourced statements | Articles with unsourced statements from July 2008
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Wood drying
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This article may require cleanup to meet Wikipedia’s quality standards. Please improve this article if you can. (February 2008)
It has been suggested that Case hardening (woodworking) be merged into this article or section. (Discuss)
Wood drying (also seasoning lumber or wood seasoning) refers to reducing the moisture content of wood prior to its use.
Typically when burning wood it is best to dry it. Moisture affects the burning process leading to unburnt hydrocarbons going up the chimmney. Though if a 50% wet log is burnt at high temperature, with good heat extraction from the exhaust gas leading to a 100C exhaust temperature, only about 5% of the energy of the log is wasted evaporating and heating the water vapour. With condensers the efficiency can be further increased, though for the normal stove, the key to burning wet wood is to burn it very hot, perhaps starting the fire with dry wood.
For some purposes wood is not dried at all (it is used “green“). Often the wood needs to be in an equilibrium with the air outside (e.g. construction wood) or the air indoors (e.g. for furniture). Wood is either air-dried or kiln-dried. Usually the wood is sawn prior to the drying process, but not always (i.e. drying the whole log)
Contents
1Types of wood
2Wood-water relationships
2.1Moisture content of wood
2.2Fibre saturation point
2.3Equilibrium moisture content
2.4Moisture content of wood in service
2.5Shrinkage and swelling
3Wood drying
3.1How wood dries: the mechanisms of moisture movement
3.1.1Mechanisms for moisture movement
3.1.1.1Moisture passageways
3.1.1.2Moisture movement space
3.2Driving forces for moisture movement
3.2.1Capillary action
3.2.2Moisture content differences
3.2.3Moisture movement directions for diffusion
3.3Reasons for splits and cracks during timber drying and their control
3.4Influence of temperature, relative humidity and rate of air circulation
3.5Classification of timbers for drying
3.6A simple model for wood drying
4Methods of drying timber
4.1Air drying
4.2Kiln drying
4.2.1Kiln drying schedules
4.3Drying defects
5References
6Related Journal
7Further reading
8External links
9See also
Types of wood
Wood is divided, according to its botanical origin, into two kinds: Softwoods from coniferous trees and hardwoods from broadleaved trees. Structurally softwoods are generally simple in structure and lighter whereas hardwoods are generally complex in structure and harder. However, in Australia softwoods generally refer to rainforest trees and hardwoods refer to sclerophyllous species namely Eucalyptusspp.
Softwood (like pine wood) is much lighter and easier to process than the heavy hardwood (like fruit tree wood). The density of softwoods ranges between 350-700 kg/m³, while hardwoods are 450-1250 kg/m³. Both consist of approximately 12 % moisture (Desch and Dinwoodie, 1996). Due to the more dense and complex structure of hardwood, the permeability is very low in comparison to softwood, thus making it more difficult to dry. Even though there are about hundred times more species of hardwood trees than softwood trees, the ability to process and dry softwood faster and more easily makes it the main supply of commercial wood today.
Wood-water relationships
The timber of living trees and freshly felled logs contains a large amount of water, which often constitutes over 50% of the woods actual weight. Water has a significant influence on wood: wood continually exchanges moisture (water) with its surroundings, although the rate of exchange is strongly affected by the degree wood is sealed.
Water in wood may be present in two forms:
Free water: The bulk of water contained in the cell lumina is only held by capillary forces: it is not bound chemically and is termed free water. Free water is not in the same thermodynamic state as liquid water: energy is required to overcome the capillary forces. Furthermore, free water may contain chemicals, altering the drying characteristics.
Bound or hygroscopic water: Bound water is bound to the wood via hydrogen bonds. The attraction of wood for water arises from the presence of free hydroxyl (OH) groups in the cellulose, hemicelluloses and lignin molecules in the cell wall. The hydroxyl groups are negatively charged electrically. Water is a polar liquid. The free hydroxyl groups in cellulose attract and hold water by hydrogen bonding.
Water in cell lumina may be in the form of water vapour, but the total amount is normally negligible, at normal temperatures and moisture contents.
Moisture content of wood
The moisture content of wood is calculated by the formula (Siau, 1984):
Here, is the green mass of the wood, is its oven-dry mass (the attainment of constant mass generally after drying in an oven set at 103 +/- 2 °C for 24 hours as mentioned by Walker et al., 1993). This can also be expressed as a fraction of the mass of the water and the mass of the oven-dry wood rather than a percentage, for example, 0.59 kg/kg (oven dry basis) expresses the same moisture content as 59% (oven dry basis).
Students in the United Kingdom would recognise this formula written as
Where the wet weight is the weight of the original ‘wet’ sample and the dry weight being the weight of the sample after drying in an oven. Moisture contents being expressed as a percentage.
Fibre saturation point
When green wood dries, the first water to go is the free water from the cell lumina. It is held only by the capillary forces. Most physical properties, such as strength and shrinkage, are unaffected by the removal of free water. The fibre saturation point (FSP) is defined as the moisture content at which free water should be completely gone, while the cell walls are saturated with bound water. In most woods, the fibre saturation point is at 25 to 30% moisture content. Siau (1984) reported that the fibre saturation point (kg/kg) is dependent on the temperature T (°C) according to the following equation:
Keey et al. (2000) use a different definition of the fibre saturation point (equilibrium moisture content of wood in an environment of 99% relative humidity).
Many important properties of wood show a considerable change as the wood is dried below the fibre saturation point. These include:
Volume: ideally no shrinkage occurs until some bound water is lost, i.e. until the wood is dried below FSP.
Most strength properties show a consistent increase as the wood is dried below the FSP (Desch and Dinwoodie, 1996). An exception is impact bending strength and, in some cases toughness.
Electrical resistivity increases very rapidly with the loss of bound water when the wood dries below the FSP.
Equilibrium moisture content
Main article: Equilibrium moisture content
Wood is a hygroscopic substance. It has the ability to take in or give off moisture in the form of vapour. The water contained in wood exerts a vapour pressure of its own, which is determined by the maximum size of the capillaries filled with water at any time. If the water vapour pressure in the ambient space is lower than the vapour pressure within wood, desorption takes place. The largest sized capillaries, which are full of water at the time, empty first. The vapour pressure within the wood falls as water is successively contained in smaller and smaller sized capillaries. A stage is eventually reached when the vapour pressure within the wood equals the vapour pressure in the ambient space above the wood, and further desorption ceases. The amount of moisture that remains in the wood at this stage is in equilibrium with the water vapour pressure in the ambient space, and is termed the equilibrium moisture content or EMC (Siau, 1984). Because of its hygroscopicity, wood tends to reach a moisture content that is in equilibrium with the relative humidity and temperature of the surrounding air. The EMC of wood varies with the ambient relative humidity (a function of temperature) significantly, to a lesser degree with the temperature. Siau (1984) reported that the EMC also varies very slightly with species, mechanical stress, drying history of wood, density, extractives content and the direction of sorption in which the moisture change takes place (i.e. adsorption or desorption).
Moisture content of wood in service
Wood retains its hygroscopic characteristics after it is put into use. It is then subjected to fluctuating humidity, the dominant factor in determining its EMC. These fluctuations may be more or less cyclical, such as diurnal changes or annual seasonal changes. In order to minimise the changes in wood moisture content or the movement of wooden objects in service, wood is usually dried to a moisture content that is close to the average EMC conditions to which it will be exposed. These conditions vary for interior uses compared with exterior uses in a given geographic location. For example, according to the Australian Standard for Timber Drying Quality (AS/NZS 4787, 2001), the EMC is recommended to be 10-12% for the majority of Australian states, although extreme cases may be up to 15 to 18% for some places in Queensland, Northern Territory, Western Australia and Tasmania. However, the EMC may be as low as 6 to 7% in dry centrally heated houses and offices or in permanently air-conditioned buildings.
The primary reason for drying wood to a moisture content equivalent to its mean EMC under use conditions is to minimise the dimensional changes (or movement) in the final product.
Shrinkage and swelling
Shrinkage and swelling may occur in wood when the moisture content is changed (Stamm, 1964). Shrinkage occurs as moisture content decreases too much, while swelling takes place when it increases. Volume change is not equal in all directions. The greatest dimensional change occurs in a direction tangential to the growth rings. Shrinkage from the pith outwards, or radially, is usually considerably less than tangential shrinkage, while longitudinal (along the grain) shrinkage is so slight as to be usually neglected. The longitudinal shrinkage is 0.1 to 0.3%, in contrast to transverse shrinkages, which is 2-10%. Tangential shrinkage is often about twice as great as in the radial direction, although in some species it may be as much as five times as great. The shrinkage is about 5 to 10% in the tangential direction and about 2 to 6% in the radial direction (Walker et al., 1993).
Differential transverse shrinkage of wood is related to:
the alternation of late wood and early wood increments within the annual ring;
the influence of wood rays in the radial direction (Kollmann and Cote, 1968)
the features of the cell wall structure such as microfibril angle modifications and pits; and,
the chemical composition of the middle lamella.
Wood drying
Wood drying may be described as the art of ensuring that gross dimensional changes through shrinkage are confined to the drying process. Ideally, wood is dried to that equilibrium moisture content as will later (in service) be attained by the wood. Thus, further dimensional change will be kept to a minimum.
It is probably impossible to completely eliminate movement in wood, but this may be approximated by chemical modification. This is the treatment of wood with chemicals to replace the hydroxyl groups with other hydrophobic functional groups of modifying agents (Stamm, 1964). Among all the existing processes, wood modification with acetic anhydride has considerable promise due to the high anti-shrink or anti-swell efficiency (ASE) attainable without damaging the wood properties. However, acetylation of wood has been slow to be commercialised due to the cost, corrosion and the entrapment of the acetic acid in wood. There is extensive literature relating to the chemical modification of wood (Rowell, 1983, 1991; Kumar, 1994; Haque, 1997).
Drying timber is one approach for adding value to sawn products from the primary wood processing industries. According to the Australian Forest and Wood Products Research and Development Corporation (FWPRDC), green sawn hardwood, which is sold at about $350 per cubic metre or less, increases in value to $2,000 per cubic metre or more with drying and processing. However, currently-used conventional drying processes often result in significant quality problems from cracks, both externally and internally, reducing the value of the product. As an example, in Queensland alone (Anon, 1997), assuming that 10% of the dried softwood is devalued by $200 per cubic metre because of drying defects, sawmillers are losing about $5 million per year in that State alone. Australia wide this could be $40 million per year for softwood and an equal or higher amount for hardwood. Thus proper drying under controlled conditions (prior to use) is of great importance in timber utilisation in any country, where climatic conditions vary considerably at different times of the year.
Drying, if carried out promptly after the felling of trees, also protects timber against primary decay, fungal stain and attack by certain kinds of insects. Organisms, which cause decay and stain, generally cannot thrive in timber with a moisture content below 20%. Several, though not all, insect pests can live only in green timber. Dried wood is less susceptible to decay than green wood (above 20% moisture content).
Apart from the above important advantages of drying timber, the following points are also significant (Walker et al., 1993; Desch and Dinwoodie, 1996):
Dried timber is lighter, and hence the transportation and handling costs are reduced.
Dried timber is stronger than green timber in most strength properties.
Timbers for impregnation with preservatives have to be properly dried if proper penetration is to be accomplished, particularly in the case of oil-type preservatives.
In the field of chemical modification of wood and wood products, the material should be dried to a certain moisture content for the appropriate reactions to occur.
Dry wood works, machines, finishes and glues better than green timber. Paints and finishes last longer on dry timber.
The electrical and thermal insulation properties of wood are improved by drying.
Prompt drying of wood immediately after felling therefore results in significant upgrading of, and value adding to, the raw timber. Drying enables substantial long term economy in timber utilisation by rationalising the utilisation of timber resources. The drying of wood is thus an area for research and development, which concerns many researchers and timber companies around the world.
How wood dries: the mechanisms of moisture movement
Water in wood normally moves from zones of higher to zones of lower moisture content (Walker et al., 1993). In simple terms, this means that drying starts from the outside and moves towards the centre, and it also means that drying at the outside is also necessary to expel moisture from the inner zones of the wood. Wood, after a period of time, attains a moisture content in equilibrium with the surrounding air (the EMC, as mentioned earlier).
Mechanisms for moisture movement
Moisture passageways
The basic driving force for moisture movement is chemical potential. However, it is not always straightforward to relate chemical potential in wood to commonly observable variables, such as temperature and moisture content (Keey et al., 2000). Moisture in wood moves within the wood as liquid or vapour through several types of passageways depending on the nature of the driving force, (e.g. pressure or moisture gradient), and variations in wood structure (Langrish and Walker, 1993), as explained in the next section on driving forces for moisture movement. These pathways consist of cavities of the vessels, fibres, ray cells, pit chambers and their pit membrane openings, intercellular spaces and transitory cell wall passageways. Movement of water takes place in these passageways in any direction, longitudinally in the cells, as well as laterally from cell to cell until it reaches the lateral drying surfaces of the wood. The higher longitudinal permeability of sapwood of hardwood is generally caused by the presence of vessels. The lateral permeability and transverse flow is often very low in hardwoods. The vessels in hardwoods are sometimes blocked by the presence of tyloses and/or by secreting gums and resins in some other species, as mentioned earlier. The presence of gum veins, the formation of which is often a result of natural protective response of trees to injury, is commonly observed on the surface of sawn boards of most eucalypts. Despite the generally higher volume fraction of rays in hardwoods (typically 15% of wood volume), the rays are not particularly effective in radial flow, nor are the pits on the radial surfaces of fibres effective in tangential flow (Langrish and Walker, 1993).
Moisture movement space
The available space for air and moisture in wood depends on the density and porosity of wood. Porosity is the volume fraction of void space in a solid. The porosity is reported to be 1.2 to 4.6% of dry volume of wood cell wall (Siau, 1984). On the other hand, permeability is a measure of the ease with which fluids are transported through a porous solid under the influence of some driving forces, e.g. capillary pressure gradient or moisture gradient. It is clear that solids must be porous to be permeable, but it does not necessarily follow that all porous bodies are permeable. Permeability can only exist if the void spaces are interconnected by openings. For example, a hardwood may be permeable because there is intervessel pitting with openings in the membranes (Keey et al., 2000). If these membranes are occluded or encrusted, or if the pits are aspirated, the wood assumes a closed-cell structure and may be virtually impermeable. The density is also important for impermeable hardwoods because more cell-wall material is traversed per unit distance, which offers increased resistance to diffusion (Keey et al., 2000). Hence lighter woods, in general, dry more rapidly than do the heavier woods. The transport of fluids is often bulk flow (momentum transfer) for permeable softwoods at high temperature while diffusion occurs for impermeable hardwoods (Siau, 1984). These mechanisms are discussed below.
Driving forces for moisture movement
Three main driving forces used in different version of diffusion models are moisture content, the partial pressure of water vapour, and the chemical potential (Skaar, 1988; Keey et al., 2000). These are discussed here, including capillary action, which is a mechanism for free water transport in permeable softwoods. Total pressure difference is the driving force during wood vacuum drying.
Capillary action
Capillary forces determine the movements (or absence of movement) of free water. It is due to both adhesion and cohesion. Adhesion is the attraction between water to other substances and cohesion is the attraction of the molecules in water to each other.
As wood dries, evaporation of water from the surface sets up capillary forces that exert a pull on the free water in the zones of wood beneath the surfaces. When there is no longer any free water in the wood capillary forces are no longer of importance.
Moisture content differences
The chemical potential is explained here since it is the true driving force for the transport of water in both liquid and vapour phases in wood (Siau, 1984). The Gibbs free energy per mole of substance is usually expressed as the chemical potential (Skaar, 1933). The chemical potential of unsaturated air or wood below the fibre saturation point influences the drying of wood. Equilibrium will occur at the equilibrium moisture content (as defined earlier) of wood when the chemical potential of the wood becomes equal to that of the surrounding air. The chemical potential of sorbed water is a function of wood moisture content. Therefore, a gradient of wood moisture content (between surface and centre), or more specifically of activity, is accompanied by a gradient of chemical potential under isothermal conditions. Moisture will redistribute itself throughout the wood until the chemical potential is uniform throughout, resulting in a zero potential gradient at equilibrium (Skaar, 1988). The flux of moisture attempting to achieve the equilibrium state is assumed to be proportional to the difference in chemical potential, and inversely proportional to the path length over which the potential difference acts (Keey et al., 2000).
The gradient in chemical potential is related to the moisture content gradient as explained in above equations (Keey et al., 2000). The diffusion model using moisture content gradient as a driving force was applied successfully by Wu (1989) and Doe et al. (1994). Though the agreement between the moisture-content profiles predicted by the diffusion model based on moisture-content gradients is better at lower moisture contents than at higher ones, there is no evidence to suggest that there are significantly different moisture-transport mechanisms operating at higher moisture contents for this timber. Their observations are consistent with a transport process that is driven by the total concentration of water. The diffusion model is used for this thesis based on this empirical evidence that the moisture-content gradient is a driving force for drying this type of impermeable timber.
Differences in moisture content between the surface and the centre (gradient, the chemical potential difference between interface and bulk) move the bound water through the small passageways in the cell wall by diffusion. In comparison with capillary movement, diffusion is a slow process. Diffusion is the generally suggested mechanism for the drying of impermeable hardwoods (Keey et al., 2000). Furthermore, moisture migrates slowly due to the fact that extractives plug the small cell wall openings in the heartwood. This is why sapwood generally dries faster than heartwood under the same drying conditions.
Moisture movement directions for diffusion
It is reported that the ratio of the longitudinal to the transverse (radial and tangential) diffusion rates for wood ranges from about 100 at a moisture content of 5% to 2 to 4 at a moisture content of 25% (Langrish and Walker, 1993). Radial diffusion is somewhat faster than tangential diffusion. Although longitudinal diffusion is most rapid, it is of practical importance only when short pieces are dried. Generally the timber boards are much longer than in width or thickness. For example, a typical size of a green board used for this research was 6 m long, 250 mm in width and 43 mm in thickness. If the boards are quartersawn (sawing around the pith), then the width will be in the radial direction whereas the thickness will be in tangential direction, and vice versa for back-sawn (sawing through and through) boards. Most of the moisture is removed from wood by lateral movement during drying.
Reasons for splits and cracks during timber drying and their control
The chief difficulty experienced in the drying of timber is the tendency of its outer layers to dry out more rapidly than the interior ones. If these layers are allowed to dry much below the fibre saturation point while the interior is still saturated, stresses (called drying stresses) are set up because the shrinkage of the outer layers is restricted by the wet interior (Keey et al., 2000). Rupture in the wood tissues occurs, and consequently splits and cracks occur if these stresses across the grain exceed the strength across the grain (fibre to fibre bonding).
The successful control of drying defects in a drying process consists in maintaining a balance between the rate of evaporation of moisture from the surface and the rate of outward movement of moisture from the interior of the wood. The way in which drying can be controlled will now be explained. One of the most successful ways of wood drying or seasoning would be kiln drying, where the wood are placed into a kiln compartment in stacks and dried by steaming, and releasing the steam slowly.
Influence of temperature, relative humidity and rate of air circulation
The external drying conditions (temperature, relative humidity and air velocity) control the external boundary conditions for drying, and hence the drying rate, as well as affecting the rate of internal moisture movement. The drying rate is affected by external drying conditions (Walker et al., 1993; Keey et al., 2000), as will now be described.
Temperature: If the relative humidity is kept constant, the higher the temperature, the higher the drying rate. Temperature influences the drying rate by increasing the moisture holding capacity of the air, as well as by accelerating the diffusion rate of moisture through the wood. The actual temperature in a drying kiln is the dry-bulb temperature (usually denoted by Tg), which is the temperature of a vapour-gas mixture determined by inserting a thermometer with a dry bulb. On the other hand, the wet-bulb temperature (TW) is defined as the temperature reached by a small amount of liquid evaporating in a large amount of an unsaturated air-vapour mixture. The temperature sensing element of this thermometer is kept moist with a porous fabric sleeve (cloth) usually put in a reservoir of clean water. A minimum air flow of 2 m/s is needed to prevent a zone of stagnant damp air formation around the sleeve (Walker et al., 1993). Since air passes over the wet sleeve, water is evaporated and cools the wet-bulb thermometer. The difference between the dry-bulb and wet-bulb temperatures, the wet-bulb depression, is used to determine the relative humidity from a standard hygrometric chart (Walker et al., 1993). A higher difference between the dry-bulb and wet-bulb temperatures indicates a lower relative humidity. For example, if the dry-bulb temperature is 100 °C and wet-bulb temperature 60 °C, then the relative humidity is read as 17% from a hygrometric chart.
Relative humidity: The relative humidity of air is defined as the partial pressure of water vapour divided by the saturated vapour pressure at the same temperature and total pressure (Siau, 1984). If the temperature is kept constant, lower relative humidities result in higher drying rates due to the increased moisture gradient in wood, resulting from the reduction of the moisture content in the surface layers when the relative humidity of air is reduced. The relative humidity is usually expressed on a percentage basis. For drying, the other essential parameter related to relative humidity is the absolute humidity, which is the mass of water vapour per unit mass of dry air (kg of water per kg of dry air). The following equation can be used to calculate the absolute humidity from the relative humidity (Strumillo and Kudra, 1986):
Air circulation rate: Drying time and timber quality depend on the air velocity and its uniform circulation. At a constant temperature and relative humidity, the highest possible drying rate is obtained by rapid circulation of air across the surface of wood, giving rapid removal of moisture evaporating from the wood. However, a higher drying rate is not always desirable, particularly for impermeable hardwoods, because higher drying rates develop greater stresses that may cause the timber to crack or distort. At very low fan speeds, less than 1 m s-1, the air flow through the stack is often laminar flow, and the heat transfer between the timber surface and the moving air stream is not particularly effective (Walker et al., 1993). The low effectiveness (externally) of heat transfer is not necessarily a problem if internal moisture movement is the key limitation to the movement of moisture, as it is for most hardwoods (Pordage and Langrish, 1999).
Classification of timbers for drying
The timbers are classified as follows according to their ease of drying and their proneness to drying degrade:
A. Highly refractory woods: These woods are slow and difficult to dry if the final product is to be free from defects, particularly cracks and splits. Examples are heavy structural timbers with high density such as ironbark (Eucalyptus paniculata), blackbutt (E. pilularis), southern blue gum (E. globulus) and brush box (Lophostemon cofertus). They require considerable protection and care against rapid drying conditions for the best results (Bootle, 1994).
B. Moderately refractory woods: These timbers show a moderate tendency to crack and split during seasoning. They can be seasoned free from defects with moderately rapid drying conditions (i.e. a maximum dry-bulb temperature of 85 °C can be used). Examples are Sydney blue gum (E. saligna) and other timbers of medium density (Bootle, 1994), which are potentially suitable for furniture.
C. Non-refractory woods: These woods can be rapidly seasoned to be free from defects even by applying high temperatures (dry-bulb temperatures of more than 100 °C) in industrial kilns. If not dried rapidly, they may develop discolouration (blue stain) and mould on the surface. Examples are softwoods and low density timbers such as Pinus radiata.
A simple model for wood drying
The rate at which wood dries depends upon a number of factors, the most important of which are the temperature, the dimensions of the wood, and the relative humidity. Simpson and Tschernitz have developed a simple model of wood drying as a function of these three variables. Although the analysis was done for red oak, the procedure may be applied to any species of wood by adjusting the constant parameters of the model.
Simply put, the model assumes that the rate of change of the moisture content M with respect to time t is proportional to how far the wood sample is from its equilibrium moisture content Me, which is a function of the temperature T and relative humidity h:
where ? is a function of the temperature T and a typical wood dimension L and has units of time. The typical wood dimension is roughly the smallest value of () which are the radial, tangential and longitudinal dimensions respectively, with the longitudinal dimension divided by ten because water diffuses about 10 times more rapidly in the longitudinal direction (along the grain) than in the lateral dimensions. The solution to the above equation is:
Where M0 is the initial moisture content. It was found that for red oak lumber, the “time constant” ? was well expressed as:
where a, b and n are constants and psat(T) is the saturation vapor pressure of water at temperature T. For time measured in days, length in inches, and psat measured in mmHg, the following values of the constants were found for red oak lumber.
Solving for the drying time yields:
For example, at 150 deg F, using the Arden Buck Equation, the saturation vapor pressure of water is found to be about 192 mmHg. The time constant for drying a 1-inch thick red oak board at 150 deg F is then ? = 3.03 days, which is the time required to reduce the moisture content to 1/e = 37% of its initial deviation from equilibrium. If the relative humidity is 0.50, then using the Hailwood-Horrobin equation the moisture content of the wood at equilibrium is about 7.4%. The time to reduce the lumber from 85% moisture content to 25% moisture content is then about 4.5 days.
Methods of drying timber
Broadly, there are two methods by which timber can be dried: (i) natural drying or air drying, and (ii) artificial drying.
Air drying
Air drying is the drying of timber by exposing it to the air. The technique of air drying consists mainly of making a stack of sawn timber (with the layers of boards separated by stickers) on raised foundations, in a clean, cool, dry and shady place. Rate of drying largely depends on climatic conditions, and on the air movement (exposure to the wind). For successful air drying, a continuous and uniform flow of air throughout the pile of the timber needs to be arranged (Desch and Dinwoodie, 1996). The rate of loss of moisture can be controlled by coating the planks with any substance that is relatively impermeable to moisture; ordinary mineral oil is usually quite effective. Coating the ends of logs with oil or thick paint, improves their quality upon drying. Wrapping planks or logs in materials which will allow some movement of moisture, generally works very well provided the wood is first treated against fungal infection by coating in petrol/gasoline or oil. Mineral oil will generally not soak in more than 1–2 mm below the surface and is easily removed by planing when the timber is suitably dry. Benefits- It does not cost anything to use this technique. Drawbacks- It takes several months at least to air-dry the wood.
Kiln drying
The process of kiln drying consists basically of introducing heat. This may be directly, using natural gas and/or electricity or indirectly, through steam-heated heat exchangers, although solar energy is also possible. In the process, deliberate control of temperature, relative humidity and air circulation is provided to give conditions at various stages (moisture contents or times) of drying the timber to achieve effective drying. For this purpose, the timber is stacked in chambers, called wood drying kilns, which are fitted with equipment for manipulation and control of the temperature and the relative humidity of the drying air and its circulation rate through the timber stack (Walker et al., 1993; Desch and Dinwoodie, 1996).
Kiln drying provides a means of overcoming the limitations imposed by erratic weather conditions. In kiln drying as in air drying, unsaturated air is used as the drying medium. Almost all commercial timbers of the world are dried in industrial kilns. A comparison of air drying, conventional kiln and solar drying is given below:
Timber can be dried to any desired low moisture content by conventional or solar kiln drying, but in air drying, moisture contents of less than 18% are difficult to attain for most locations.
The drying times are considerably less in conventional kiln drying than in solar kiln drying, followed by air drying.
This means that if capital outlay is involved, this capital is just sitting there for a longer time when air drying is used. On the other hand, installing an industrial kiln, to say nothing of maintenance and operation, is expensive.
In addition, wood that is being air dried takes up space, which could also cost money.
In air drying, there is little control over the drying elements, so drying degrade cannot be controlled.
The temperatures employed in kiln drying typically kill all the fungi and insects in the wood if a maximum dry-bulb temperature of above 60 °C is used for the drying schedule. This is not guaranteed in air drying.
If air drying is done improperly (exposed to the sun), the rate of drying may be overly rapid in the dry summer months, causing cracking and splitting, and too slow during the cold winter months.
The significant advantages of conventional kiln drying include higher throughput and better control of the final moisture content. Conventional kiln and solar drying both enable wood to be dried to any moisture content regardless of weather conditions. For most large-scale drying operations solar and conventional kiln drying are more efficient than air drying.
Compartment-type kilns are most commonly used in timber companies. A compartment kiln is filled with a static batch of timber through which air is circulated. In these types of kiln, the timber remains stationary. The drying conditions are successively varied from time to time in such a way that the kilns provide control over the entire charge of timber being dried. This drying method is well suited to the needs of timber companies, which have to dry timbers of varied species and thickness, including refractory hardwoods that are more liable than other species to check and split.
The main elements of kiln drying are described below: a) Construction materials: The kiln chambers are generally built of brick masonry, or hollow cement-concrete slabs. Sheet metal or prefabricated aluminium in a double-walled construction with sandwiched thermal insulation, such as glass wool or polyurethane foams, are materials that are also used in some modern kilns. Some of the elements used in kiln construction. However, brick masonry chambers, with lime and (mortar) plaster on the inside and painted with impermeable coatings, are used widely and have been found to be satisfactory for many applications. b) Heating: Heating is usually carried out by steam heat exchangers and pipes of various configurations (e.g. plain, or finned (transverse or longitudinal) tubes) or by large flue pipes through which hot gases from a wood burning furnace are passed. Only occasionally is electricity or gas employed for heating. c) Humidification: Humidification is commonly accomplished by introducing live steam into the kiln through a steam spray pipe. In order to limit and control the humidity of the air when large quantities of moisture are being rapidly evaporated from the timber, there is normally a provision for ventilation of the chamber in all types of kilns. d) Air circulation: Air circulation is the means for carrying the heat to and the moisture away from all parts of a load. Forced circulation kilns are most common, where the air is circulated by means of fans or blowers, which may be installed outside the kiln chamber (external fan kiln) or inside it (internal fan kiln). Throughout the process, it is necessary to keep close control of the moisture content using a moisture meter system in order to reduce over-drying and allow operators to know when to pull the charge. Preferably, this in-kiln moisture meter will have an auto-shutoff feature.
Kiln drying schedules
Satisfactory kiln drying can usually be accomplished by regulating the temperature and humidity of the circulating air to suit the state of the timber at any given time. This condition is achieved by applying kiln-drying schedules. The desired objective of an appropriate schedule is to ensure drying timber at the fastest possible rate without causing objectionable degrade. The following factors have a considerable bearing on the schedules.
The species; because of the variations in physical, mechanical and transport properties between species.
The thickness of the timber; because the drying time is approximately inversely related to thickness and, to some extent, is also influenced by the width of the timber.
Whether the timber boards are quarter-sawn, back-sawn or mixed-sawn; because sawing pattern influences the distortion due to shrinkage anisotropy.
Permissible drying degrade; because aggressive drying schedules can cause timber to crack and distort.
Intended use of timber; because the required appearance of the timber surface and the target final moisture contents are different depending on the uses of timber.
Considering each of the factors, no one schedule is necessarily appropriate, even for similar loads of the same species. This is why there is so much timber drying research, including this work, focused on the development of effective drying schedules.
Drying defects
Drying defects are the most common form of degrade in timber, next to natural problems such as knots (Desch and Dinwoodie, 1996). There are two broad categories of drying defects (some defects involve both causes):
defects that arise due to the shrinkage anisotropy. This leads to warping: cupping, bowing, twisting, spring and diamonding.
defects that arise due to uneven drying. This leads to the rupture of the wood tissue: checks (surface, end and internal), end splits, honey-combing and case hardening. Another such defect is collapse, often seen as a corrugation, or “washboarding” of the wood surface (Innes, 1996). Collapse is a defect that results from the physical flattening of fibres, above the fibre saturation point (thus not a form of shrinkage anisotropy).
Australian and New Zealand Standard Organisations (AS/NZS 4787, 2001) have developed a standard for timber quality. Their five criteria for measuring drying quality:
moisture content gradient and presence of residual drying stress (case-hardening);
surface, internal and end checks;
collapse;
distortions;
and discolouration caused by drying.
This standard also indicates how to assess each of these drying quality criteria and provides a classification to express drying quality.
References
^Simpson, William; John Tschernitz (1979). Importance of Thickness Variation in Kiln Drying Red Oak Lumber. Madison, Wisconsin: Western Dry Kiln Clubs. http://ir.library.oregonstate.edu/dspace/bitstream/1957/5722/1/Importance_Thick_ocr.pdf. Retrieved 2008-11-15.
ABARE (2000). National Plantation Inventory, March, 2000. 4p.
Anon. (1997). Timber markets, home and away: Australian growers capitalising on international demand. Pie, Newsletter of Australia’s International and National Primary Industries and Energy (PIE) R&D Organisations. Volume 7 (Summer Issue): p14.
Bootle, K.R. (1994). Wood in Australia: Types, Properties and Uses. McGraw-Hill Book Company, Sydney. 443p.
Desch, H.E. and Dinwoodie, J.M. (1996). Timber: Structure, Properties, Conversion and Use. 7th ed. Macmillan Press Ltd., London. 306p.
Doe, P.D., Oliver, A.R. and Booker, J.D. (1994). A Non-Linear Strain and Moisture Content Model of Variable Hardwood Drying Schedules. Proc. 4th IUFRO International Wood Drying Conference, Rotorua, New Zealand. 203-210pp.
Haque, M.N. (1997). The Chemical Modification of Wood with Acetic Anhydride. MSc Dissertation. The University of Wales, Bangor, UK. 99p.
Hoadley, R. Bruce (2000). Understanding Wood: A Craftsman’s Guide to Wood Technology (2nd. ed.). Taunton Press. ISBN 1-56158-358-8.
Innes, T. (1996). Improving Seasoned Hardwood Timber Quality with Particular Reference to Collapse. PhD Thesis. University of Tasmania, Australia. 172p.
Keey, R.B., Langrish, T.A.G. and Walker, J.C.F. (2000). Kiln-Drying of Lumber. Springer, Berlin. 326p.
Kollmann, F.F.P. and Cote, W.A.J. (1968). Principles of Wood Science and Technology. I. Solid Wood. Springer-Verlag, NewYork. 592p.
Kumar, S. (1994). Chemical modification of wood. Wood and Fiber Sci., 26(2):270-280.
Langrish, T.A.G. and Walker, J.C.F. (1993). Transport Processes in Wood. In: Walker, J.C.F. Primary Wood Processing. Chapman and Hall, London. pp121–152.
Panshin, A.J. and de Zeeuw, C. (1970). Textbook of Wood Technology. Volume 1, Third Edition. McGraw-Hill, New York, 705 p.
Pordage, L.J. and Langrish, T.A.G. (1999). Simulation of the effect of air velocity in the drying of hardwood timber. Drying Technology – An International Journal, 17(1&2):237-256.
Rasmussen, E.F. (1988). Forest Products Laboratory, U.S. Deptartment of Agriculture.. ed. Dry Kiln Operators Manual. Hardwood Research Council.
Rowell, R.M. (1983). Chemical modification of wood. Forest Product Abstract, 6(12):363-382.
Rowell, R.M. (1991). Chemical Modification of Wood. In: Hon, D.N.-S and Shiraishi, N. (eds), Wood and Cellulosic Chemistry. pp. 703-756. Marcel Dekker, Inc., New York.
Siau, J.F. (1984). Transport processes in wood. Springer-Verlag, NewYork. 245p.
Sjostrom, E. (1993). Wood Chemistry: Fundamentals and Applications. Academic Press Limited, London. 293p.
Skaar, C. (1988). Wood Water Relations. Springer-Verlag, NewYork. 283p.
Stamm, A. J. (1964). Wood and Cellulose Science. Ronald Press, New York. 509p.
Standard Australia (2000). Timber – Classification into Strength Groups. Australian/New Zealand Standard (AS/NZS) 2878. Sydney. 36p.
Standard Australia (2001). Timber – Assessment of Drying Quality. Australian/New Zealand Standard (AS/NZS) 4787. Sydney. 24p.
Strumillo, C. and Kudra, T. (1986). Drying: Principles, Applications and Design. Gordon and Breach Science Publishers, New York. 448p.
Walker, J.C.F., Butterfield, B.G., Langrish, T.A.G., Harris, J.M. and Uprichard, J.M. (1993). Primary Wood Processing. Chapman and Hall, London. 595p.
Wise, L.E. and Jahn, E.C. (1952). Wood Chemistry. Vol 2. Reinhold Publishing Corp., New York. 1343p.
Wu, Q. (1989). An Investigation of Some Problems in Drying of Tasmanian Eucalypt Timbers. M.Eng. Sc. Thesis, University of Tasmania. 237p.
Related Journal
Drying Technology
Further reading
This Entry is first contributed as an edited extract from the Chapter 1 of Ph.D. Thesis by Dr. Nawshadul Haque or Nawshad Haque
External links
Northern Hardwood Initiative: Drying Hardwoods – Page Currently Not Found
Vacuum Kiln Drying Info
Wood Drying Information
TRADA: Timber Research and Development Association
See also
Wood
Retrieved from “http://en.wikipedia.org/wiki/Wood_drying”
Categories: Timber seasoning | Woodworking | WoodHidden categories: Articles needing cleanup from February 2008 | All pages needing cleanup | Articles to be merged from September 2009 | All articles to be merged | All articles with unsourced statements | Articles with unsourced statements from March 2007
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Eastpoint is a census-designated place (CDP) in Franklin County, Florida, United States. The population was 2,158 at the 2000 census.
Contents
1Geography
2Demographics
3Education
4References
Geography
Eastpoint is located at 29°44?30?N84°52?37?W? / ?29.74167°N 84.87694°W? / 29.74167; -84.87694 (29.741560, -84.876951).
According to the United States Census Bureau, the CDP has a total area of 7.3 square miles (19.0 km²), all of it land.
Demographics
As of the census of 2000, there were 2,158 people, 804 households, and 612 families residing in the CDP. The population density was 294.4 people per square mile (113.7/km²). There were 911 housing units at an average density of 124.3/sq mi (48.0/km²). The racial makeup of the CDP was 96.57% White, 0.79% African American, 0.42% Native American, 0.09% Asian, 0.56% from other races, and 1.58% from two or more races. Hispanic or Latino of any race were 1.67% of the population.
There were 804 households out of which 36.3% had children under the age of 18 living with them, 59.3% were married couples living together, 11.4% had a female householder with no husband present, and 23.8% were non-families. 18.7% of all households were made up of individuals and 6.8% had someone living alone who was 65 years of age or older. The average household size was 2.61 and the average family size was 2.95.
In the CDP the population was spread out with 26.4% under the age of 18, 7.6% from 18 to 24, 28.0% from 25 to 44, 24.6% from 45 to 64, and 13.5% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 99.6 males. For every 100 females age 18 and over, there were 96.4 males.
The median income for a household in the CDP was $30,324, and the median income for a family was $29,940. Males had a median income of $23,750 versus $25,179 for females. The per capita income for the CDP was $13,382. About 6.3% of families and 12.1% of the population were below the poverty line, including 17.0% of those under age 18 and 6.7% of those age 65 or over.
Education
Eastpoint is within the Franklin County School District system. The Franklin County School, a K-12 school, houses the district’s elementary, middle and high school programs. It is located in Eastpoint.
References
^ ab“American FactFinder”. United States Census Bureau. http://factfinder.census.gov. Retrieved 2008-01-31.
^“US Board on Geographic Names”. United States Geological Survey. 2007-10-25. http://geonames.usgs.gov. Retrieved 2008-01-31.
^“US Gazetteer files: 2000 and 1990″. United States Census Bureau. 2005-05-03. http://www.census.gov/geo/www/gazetteer/gazette.html. Retrieved 2008-01-31.
This Hradec Králové Region location article is a stub. You can help Wikipedia by expanding it. v•d•e
Retrieved from “http://en.wikipedia.org/wiki/St%C4%9B%C5%BEery”
Categories: Villages in the Czech Republic | Hradec Králové District | Cities, towns and villages in Hradec Králové District | Hradec Králové Region geography stubs
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This page was last modified on 12 July 2008 at 13:50.
Xiamen University (XMU, Latin: Universitas Amoiensis, Pinyin: Xiàmén Dàxué, POJ: E-mng Toa-hak, Simplified Chinese: ????), colloquially known as Xia Da (Pinyin: Xià Dà, POJ: E-toa, Simplified Chinese: ??), located in Xiamen, Fujian Province, is the first university in China founded by overseas Chinese. Before 1949, it was named as : University of Amoy. The school motto: “Pursue Excellence, Strive for Perfection (????, ????)”. This university rank is 13 in China.
Contents
1History
2Campus
3Faculties
4Famous alumni
5See also
6References
7External links
History
Statue of Mr.Tan Kah Kee, in front of his memorial hall located in Xiamen University.
Xiamen University
Statue of Chen Jungrun, Xiamen University
Jiannan Auditorium of Xiamen University
Xiamen University Playground
Xiamen University
Xiamen University Campus with “Kah Kee” building complex in the center and student dorms in the foreground
XMU at dusk
In 1919 Mr. Tan Kah Kee (???; Pinyin: Chen Jiageng), the well-known overseas Chinese leader, donated millions of dollars to establish and endow Xiamen University, officially founded in 1921. It is regarded as one of the most prestigious and selective universities in China.
Mr. Tan handed over Xiamen University to the government in 1937 due to lack of funds, and the institution subsequently became a national university.
In 1938, at the outbreak of the Second Sino-Japanese War, the university temporary relocated to Changting(??) in Min Xi(??) county, western Fujian.
At the end of World War II in 1946, Xiamen University moved back to Xiamen and resumed normal operations.
In 1952, Xiamen University became a comprehensive university, and has been designated as a national key university since 1962.
When the Cultural Revolution began in 1966, daily operations at the University were suspended and a subsidiary of faculties moved to Fuzhou, forming the initial polytechnic departments of Fuzhou University.
Campus
Xiamen University is famous for its beautiful campus. Located at the foot of the green mountains, facing the blue ocean and surrounded by Xiamen bay. The main campus is picturesque with beautiful scenery and parks. The university has campuses at Jimei and Zhangzhou in addition to the Xiamen campus located in the southern part of Xiamen Island.
Xiamen University has a constructed area of 2.6 million square meters and its libraries (the Xiamen University Libraries) hold 3.5 million volumes. The scope and level of its high-speed information network on campus is rated at the top of all universities in China and has become the one of the main injunctions of CERNET2.
Faculties
At June 1, 2004, Xiamen University had 20 schools containing 43 departments, and many key research institutes.
School of Humanities
School of Foreign Languages & Cultures
School of Journalism& Communication
School of Law
School of Public Affairs
College of Economics
School of Management
College of Art Education
Chemistry & Chemical Engineering College
School of Physics and Mechanical & Electrical Engineering
College of Oceanography & Environment
School of Life Science
School of Computer and Information Engineering
School of Mathematics
Software School
Medical College
School of Architecture and Civil Engineering
Overseas Education College
Adult Education College
Professional Technical College
Internet Education College
Famous alumni
Chen Jingrun – Mathematician
Zeng Chengkui – Biologist
See also
List of universities in the People’s Republic of China
GU8 Global consortium of 8 universities
References
External links
Wikimedia Commons has media related to: Xiamen University
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Tsinghua University · Peking University · Beihang University · Beijing Institute of Technology · Renmin University of China · Beijing Normal University · China Agricultural University · Minzu University of China
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National University of Defense Technology · Hunan University · Central South University
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Chongqing University
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Sichuan University · University of Electronic Science and Technology of China
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Sun Yat-sen University · South China University of Technology
Project 211
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Project 211, People’s Republic of China (211??)
Higher education and Universities in China
Beijing
Beijing Foreign Studies University · Beijing Forestry University · Beijing Institute of Technology · Beijing Jiaotong University · Beijing Normal University · Beijing University of Aeronautics and Astronautics · Beijing University of Chemical Technology · Beijing University of Chinese Medicine · Beijing University of Posts and Telecommunications · Beijing University of Technology · Peking Union Medical College · Peking University · Renmin University of China · Tsinghua University · Central Conservatory of Music · Central University of Finance and Economics · China Agricultural University · China University of Geosciences · China University of Mining and Technology · China University of Political Science and Law · Communication University of China · University of International Business and Economics · University of Science and Technology Beijing ·Minzu University of China · North China Electric Power University ·
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Shanghai International Studies University · Shanghai Jiao Tong University · Shanghai University · Shanghai University of Finance and Economics · Fudan University · Donghua University · East China Normal University ·
East China University of Science and Technology · Tongji University · Second Military Medical University · Southeast University ·
Tianjin
Tianjin Medical University · Tianjin University · Nankai University ·
Chongqing
Chongqing University ·
Anhui
Anhui University · University of Electronic Science and Technology of China · Hefei University of Technology ·
Fujian
Xiamen University · Fuzhou University ·
Guangdong
Guangzhou University of Chinese Medicine · Sun Yat-sen University · South China Normal University · South China University of Technology · Jinan University ·
Guizhou
Guizhou University ·
Gansu
Lanzhou University ·
Hebei
Hebei University of Technology ·
Heilongjiang
Harbin Engineering University · Harbin Institute of Technology · Northeast Agricultural University · Northeast Forestry University ·
Henan
Zhongnan University of Economics and Law · Zhengzhou University ·
Hubei
Wuhan University · Wuhan University of Technology · Huazhong Agricultural University · Huazhong Normal University · Huazhong University of Science and Technology ·
Hunan
Central South University · Hunan Normal University · Hunan University · National University of Defense Technology ·
Jiangsu
Nanjing Agricultural University · Nanjing Normal University · Nanjing University · Nanjing Aeronautics and Astronautics University · Nanjing University of Science and Technology · Soochow University · China Pharmaceutical University · Jiangnan University ·Hohai University ·
Jiangxi
Nanchang University ·
Jilin
Jilin University · Yanbian University · Northeast Normal University ·
Liaoning
Liaoning University · Dalian Maritime University ·
Dalian University of Technology · Northeastern University ·
Shaanxi
Chang’an University · Xi’an Jiaotong University · Xidian University · Fourth Military Medical University · Northwest A&F University · Northwest University ·
Northwestern Polytechnical University ·
Shandong
China University of Petroleum · Shandong University · Ocean University of China ·
Shanxi
Taiyuan University of Technology ·
Sichuan
Sichuan Agricultural University · Sichuan University · Southwest Jiaotong University ·
Southwestern University of Finance and Economics ·
Yunnan
Yunnan University ·
Zhejiang
Zhejiang University ·
Guangxi
Guangxi University ·
Inner Mongolia
Inner Mongolia University ·
Xinjiang
Xinjiang University · Xinjiang Medical University ·
Project 985
v•d•e
Universities and colleges in Fujian
National
Huaqiao University ? ·Xiamen University ?
Provincial
Fujian Agriculture and Forestry University · Fujian University of Traditional Chinese Medicine · Fujian Medical University · Fujian Normal University · Fujian University of Technology · Fuzhou University · Jimei University · Longyan University · Minjiang University · Putian University · Quanzhou Normal College · Zhangzhou Normal University · Wuyi University
Private
Yang-en University
See also: List of universities in China
Retrieved from “http://en.wikipedia.org/wiki/Xiamen_University”
Categories: Global U8 Consortium | Universities and colleges in Xiamen | Universities in Fujian | Project 211 | Educational institutions established in 1921
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This page was last modified on 5 February 2010 at 11:15.
Under Secretary of Commerce for International Trade
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Under Secretary Christopher Padilla
The Under Secretary for International Trade is a position within the United States Department of Commerce that leads the International Trade Administration. The Under Secretary also serves as a member of the Tourism Policy Council and the National Intellectual Property Council. The Under Secretary participates in the development of U.S. trade policy; identifies and resolves market access and compliance issues; administers U.S. trade laws; and undertakes a range of trade promotion and trade advocacy efforts. The current Under Secretary for International Trade is Christopher A. Padilla.
The Under Secretary is appointed by the President with the advice and consent of the U.S. Senate. The position was created as a result of a June 16, 1982 law that did not require for an Under Secretary for International Trade until January 1, 1989. The Under Secretary is paid on a rate paytable for Level III of the Executive Schedule, meaning he or she receives a basic annual salary of $152,000 as of 2006. Previous Under Secretaries include Franklin L. Lavin, Acting Under Secretary Rhoda Keenum, and Robert S. LaRussa.
References
^ ab“”trade.gov – Christopher A. Padilla”". http://trade.gov/press/bios/padilla.asp. Retrieved September 26, 2007.
^“”US CODE: Title 22,2124. Tourism Policy Council”". http://www.law.cornell.edu/uscode/html/uscode22/usc_sec_22_00002124—-000-.html. Retrieved September 22, 2007.
^“”US CODE: Title 15,1128. National Intellectual Property Law Enforcement Coordination Council”". http://www.law.cornell.edu/uscode/html/uscode15/usc_sec_15_00001128—-000-.html. Retrieved September 22, 2007.
^“”US CODE: Title 19,2171. Structure, functions, powers, and personnel”". http://www.law.cornell.edu/uscode/html/uscode19/usc_sec_19_00002171—-000-notes.html. Retrieved September 22, 2007.
^“”Salary Table 2006-EX”". http://www.opm.gov/oca/06tables/html/ex.asp. Retrieved September 22, 2007.
^“”Remarks By Under Secretary for International Trade Franklin L. Lavin Before The American Chamber Of Commerce”". http://merida.usconsulate.gov/merida/Story1.html. Retrieved September 26, 2007.
^“”BCAST-ARCHIVE archives — 2005 (#71)”". http://dir.commerce.gov/cgi-bin/WA.EXE?A2=ind05&L=bcast-archive&D=1&F=l&T=0&P=6984. Retrieved September 26, 2007.
^“”Clinton Presidential Center “President Names Larussa Under Secretary for International Trade”"”. http://www.clintonpresidentialcenter.org/legacy/052300-president-names-larussa-under-secretary-for-international-trade.htm. Retrieved September 26, 2007.
v•d•e
Agencies under the United States Department of Commerce
Headquarters: Herbert C. Hoover Building · Secretary of Commerce · Deputy Secretary of Commerce
Under Secretary of Commerce for Industry and Security
Bureau of Industry and Security
Under Secretary of Commerce for Economic Affairs
Economics and Statistics Administration · Bureau of Economic Analysis · Census Bureau · Economic Development Administration
Under Secretary of Commerce for International Trade
International Trade Administration · Minority Business Development Agency
Under Secretary of Commerce and Administrator for NOAA
National Oceanic and Atmospheric Administration · National Telecommunications and Information Administration · National Oceanic and Atmospheric Administration Commissioned Corps
Under Secretary of Commerce for Intellectual Property
Patent and Trademark Office
Director of the National Institute of Standards and Technology
National Institute of Standards and Technology · National Technical Information Service
Retrieved from “http://en.wikipedia.org/wiki/Under_Secretary_of_Commerce_for_International_Trade”
Categories: United States Department of Commerce officials
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This page was last modified on 30 November 2009 at 18:42.
Dark Angel: Vampire Apocalypse is a Diablo-style hack n’ slash game by Metro 3D.
References
Dark Angel: Vampire Apocalypse (infobox details) at GameFAQs
This action game-related article is a stub. You can help Wikipedia by expanding it. v•d•e
Retrieved from “http://en.wikipedia.org/wiki/Dark_Angel:_Vampire_Apocalypse”
Categories: Action game stubs | 2001 video games | PlayStation 2 games | PlayStation 2-only games | Vampire video games | Video games developed in the United Kingdom
Marie Curie Middle School 158 (MS 158 for short) is a middle school for science and technology located in Bayside, New York with a large enrollment. Approximately 1,150 6th to 8th graders attend this school, which is named after Marie Curie, the renowned scientist and winner of the Nobel Prize in Physics and the Nobel Prize in Chemistry.
This school continues the District 26 gifted and talented program, accepting children from the 5th grade magnet program at P.S. 188 Kingsbury School, P.S. 203 Oakland Gardens School, P.S. 41, and P.S. 31 Bayside School.
Former math teacher Marie Nappi became principal after Charles DeMeo retired on June 30, 2005.
The graduation ceremony of eighth graders was traditionally held at St. Francis Preparatory School. It is now held at St. John’s University.
Contents
1Extracurriculars
2Programs
3Special Education
4Community
5Trivia
6External links
Extracurriculars
Activities include basketball (girls and boys teams), volleyball, softball, newspaper club, peer tutoring, yearbook club, dance, chorus, orchestra, All Star Jazz Ensemble, peer mediation club, recycling and other clubs and organizations. The school also provides a National Junior Honor Society which allows students to do community service for the school. 7th grade students need 15 hours to be submitted into the society and 40 hours for continuing 8th grade members.
Programs
MS 158 has a Beacon program, a city-run youth-service organization, and many different after school programs as well. A Saturday morning program offers tutoring and academic support.
There are specific gifted and talented classes as well as a magnet program in math, science and technology enrichment. A program for hearing impaired students and classes in computers, fine and performing arts and math/literacy skills are offered.
A separate SP program that begins in 7th grade is offered to high achievers not in the magnet program. The pace of instruction in core academics is faster and Regents earth science is taught in the 8th grade. Admission to these classes is based upon 6th grade test scores and class performance as well as teacher recommendations.
Special Education
The school has self-contained and inclusion classes for children with special needs. A separate, off-site administration, District 75, the citywide district for students with severe disabilities, runs a program for hearing-impaired students in the school. They have full access to the facilities and participation in school events.
Community
Two community-based organizations are housed at the school. The Beacon Program is in its 12th year. This program services the community with many student and adult support programs. The program operates from 5pm to 10pm each day .
Trivia
The last 9th grade class graduated in 2006.
Struggling students can receive help through programs such as peer tutoring and the extended day program.
Additionally, the Mathcounts team placed first in the Queens Chapter in 2009.
Students can take a Spanish proficiency exam and two Regents examinations before high school.
About 10 percent of the students are recent immigrants from China and South Korea. There are small ESL classes for language instruction.
An assistant principal and guidance counselor oversee each incoming class for its entire three-year stay.
6th graders stay with the same teacher for three periods each day of instruction in reading, language arts, and social studies instead of moving from class to class.
“Up” and “down” staircases keep students moving during changes of classes.
Offers gym classes to 8th grade SP and Magnet classes as of 2009, but for only one day of the week.
This year’s Mathcounts team consists of a mix of 8th graders and 7th graders. There is 1 very smart 7th grader. (Lies 8th graders are better 8D) (Then go beat all the 7th graders in countdown :3)
External links
Official School Website
MS 158 – Marie Curie Middle School (Previous Site)
List of public elementary schools in New York City · Empowerment Schools
Retrieved from “http://en.wikipedia.org/wiki/Marie_Curie_Middle_School_158″
Categories: New York City Department of Education | Public education in New York CityHidden categories: All articles with unsourced statements | Articles with unsourced statements from September 2008
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is the green mass of the wood, 
is its oven-dry mass (the attainment of constant mass generally after drying in an oven set at 103 +/- 2 °C for 24 hours as mentioned by Walker et al., 1993). This can also be expressed as a fraction of the mass of the water and the mass of the oven-dry wood rather than a percentage, for example, 0.59 kg/kg (oven dry basis) expresses the same moisture content as 59% (oven dry basis).
(kg/kg) is dependent on the temperature T (°C) according to the following equation:
) which are the radial, tangential and longitudinal dimensions respectively, with the longitudinal dimension divided by ten because water diffuses about 10 times more rapidly in the longitudinal direction (along the grain) than in the lateral dimensions. The solution to the above equation is:
