A barrier is something, either real or immaterial, that obstructs or prevents one thing from accessing another thing. A fence is a barrier in that it obstructs people from accessing what is on the opposite side of the fence. A cattle grid is a barrier to cloven-hooved animals, precenting their passage over the grid, while allowing vehicles and other animals free passage. Barrier creams are substances which prevent germs, water, the sun's rays or other substances from reaching the skin or a wound. In abstract terms, language can be a barrier to communication, if two people do not speak a common language then communication between them is seriously impaired and obstructed. Research Barrier
A ditch is a trench in the earth made by digging, particularly the term is used for a trench for draining wet land, or for making a fence to guard inclosures, or for preventing an enemy from approaching a town or fortress. In the latter sense it is called also a fosse or moat, and is dug round the rampart or wall between thoscarp and counterscarp. Research Ditch
Fences are continuous lines of obstacles artificially interposed between one portion of the surface of the land and another for the purpose of separation or exclusion. Live fences are made of hawthorn, holly, box, beech, etc; dead fences of stone, wood, and in more recent times of iron or wire. In agriculture fences are necessary both for restricting the tenant's own animals to their pasture, and for protecting his land from straying animals. The general erection of fences on farms was one of the improvements of later agriculture. Research Fence
Fence month is the thirty days extending from fifteen days before Midsummer until fifteen days after it. Fence month is the close-season when deerhunting is not allowed in Britain. Research Fence Month
A hedge is a fence formed of living trees or shrubs. Hedges are often composed of one or more of the following: Hawthorn, crab, blackthorn, holly, privet, beech, hornbeam, maple, barberry, furze, broom, alder, poplar, willow, yew, box, arborvitae, sweet-briar, etc. Although superior to dry-stone walls, they take up much room, and exhaust the soil to some extent. Hedges are probably more common in England than in any other country, though they were not very common in England until the close of the seventeenth century. Research Hedge
Agelenidae are a family of spiders, the members of which vary, with genera being moved into other families by some naturalists. The Agelenidae spin a tubular retreat from which extends either a small collar of silk, or a sheet of silk which may be large or small, and may be slightly funnel-shaped. The spiders grab prey falling onto or landing on the sheet and drag them back into their retreat to be eaten. Some times the retreat is not a web but a crevice in a wall or the junction of a wall and a garden fence post. Research Agelenidae
Operation yatso was a proposed KGB operation to disrupt relations between Greece and Turkey in 1969. Operation yatso was proposed to be a minor sabotage operation, involving a small explosive device which would be detonated close to a house owned by the Turkishconsulate in Thessaloniki, with the blame directed at a Greek citizen. The purpose of the proposed operation was to exacerbate the poor relationship between the NATO partners of Greece and Turkey thereby weakening American policy in south-east Europe. The text of the KGB special political action proposed by the Athens residency in April 1969 and published in this edited form by Vasili Mitrokhin, follows:
'The operation is codenamed Yatso. The aim and purpose of the operation is to cause moral and political damage to the south-east wing of NATO. Constant disagreements between Greece and Turkey cause great concern to the leadership of the USA and NATO and are a weak link in American policy in the area of south-east Europe. Carrying out a Lily on the Vaza could exacerbate relations between Greece and Turkey.
The operation would be carried out in the name of a Greek who had come from Turkey and was dissatisfied with the situation of the Greek minority there (there can also be another variant for carrying out the sabotage). Vaza is a two-storey house in Thessaloniki. The house and its annexe belong to the Turkish consulate-general...There is no furniture, only a table, iron troughs and a cooking stove. On the upper floor of the house there are displays with Ataturk's clothes and a photographic portrait of him. Apart from a desk there is no furniture. Next to the Vaza, about 15-20 m away, there is the two-storey building of the Turkish consulate-general. This house is also used as living accommodation for consulate officials. The Vaza and the consulate have a common courtyard. (A detailed description of the lay-out of the houses and the courtyard is attached.) The most suitable place for planting a Bouquet is in the bushes growing about one metre from the Vaza. The Vaza is not open to the general public. It can be visited with the permission of the Turkishconsulate; a special official is assigned to watch over the Vaza and to accompany visitors to the Vaza. The Vaza and the consulate are guarded round the clock by two gendarmes. The guard posts are mobile and the approaches to Vaza are restricted. The most convenient time to approach the target is at nightfall. Specifications of the Bouquet. The size and weight of the Bouquet must be related to the results which are desired from the attack on the Vaza. Evidently, there is no point in causing serious damage to the Vaza; it is better to achieve a moral and political effect. When calculating the force of the Bouquet, one must bear in mind that the distance from the Splash to the consulate living quarters is 15 - 20 m. ...In order to increase the impact and achieve the desired results, the Bouquet must be wrapped in a newspaper published in Turkey for Greek citizens. The temperature in Thessaloniki ranges in winter from
w zero to 14 C, while in summer it ranges from 24 C upwards. Occasionally there are thick fogs.
The Gardener must be sent to the country as a foreign tourist at the height of the tourist season. The greatest influx of tourists occurs from June to August. According to his identity documents, the Gardener's identity documents must show him to be a citizen of a country friendly to Greece or a neutral state (the USA, Britain, East Germany, Austria, France, Italy, Canada, Libya), excluding the Scandinavian countries, Denmark, Holland and Belgium. On arriving in Athens the Gardener can hire a motor car, visit historical sites in the south of the country and some of the islands. Simultaneously, the Gardener is acclimatizing himself and becoming fully accustomed to the situation in the country. After collecting the Bouquet from the residency via a DLB, the Gardener travels to Thessaloniki by rail. The estimated time span for carrying out the Lily and for the Gardener's activities is as follows: After arriving in Athens, the Gardener can hire a motor car the next day, spend one or two days in Athens and its suburbs, then travel the following route by
car: Athens-Patrais-Navplion-Epidhauros-Korinthos-Athens. This route will take the Gardener four or five days. On arriving in Athens, the Gardener books into a hotel.
The next day he places a signal indicating he is ready to carry out the DLB operation to receive the Bouquet. The DLB operation takes place next day. After collecting the Bouquet, the Gardener leaves by the next train to Thessaloniki, having previously booked out from the hotel. A train leaves Athens at 11.42, and arrives at Thessaloniki at 19.29; he travels in a first-class compartment. At Thessaloniki he does not stay at a hotel. In order to acquaint himself with the situation around the Vaza he walks past the Vaza after checking for surveillance. As darkness falls, the Gardener goes off on a route of his own choice, but at the final stage goes into the old fort, where he inserts the little flower into the Bouquet. From the northern gates of the fort, the Gardener goes down Isail Street which leads to the Vaza and comes out on St Paul Street. This takes 15-20 minutes. On coming out on to Isail Street, the Gardener goes from the garage towards St Paul Street. While moving along the fence, the Gardener causes the Splash. The Gardener can throw the Bouquet into the bushes which are close to the Vaza fence or he can drop the Bouquet on the ground inside the Vaza fence. (A diagram of the route and of the location of the installations is attached).
After completing the Splash, the Gardener goes out on Ayios Dhimitrios Street and moves in the direction of the stadium (20-25 minutes walk). In the stadium area there is some waste ground where the Gardener can bury the TWA or BOAC airline bag used for keeping and transporting the Bouquet. From Thessaloniki, the Gardener can go to Athens by train or air (buying the air ticket 5-10 minutes before take-off, using any surname). If the situation does not permit the Gardener to put the Bouquet together, then he can get rid of it ... in the area of the stadium where there is some waste ground. If he attracts the attention of the Vaza security guard, he must say
that he is a foreign tourist going from the fort to the delta Hotel, where he intends to spend the night, but that this is his first visit to the town and he is not sure of the way to the hotel.' Research Operation Yatso
Photography is the art, and sometimes business, of taking and also sometimes producing and printing photographs.
Early cameras operated upon the principle of allowing light reflected from a subject to fall upon a light-sensitive chemical impregnated plate, later plastic film. These plates or films were then treated with other chemicals to prevent further sensitivity to light, thereby fixing the image which was then printed. Later digital cameras evolved which used electronic light sensors to record the image in a binary digital file on a memory card.
If too much light is allowed in to the camera, the picture will be over exposed, and will look bright and indistinct. If not enough light is allowed in, the picture will be under exposed and will look dark and indistinct. It is less common for photographs to be over exposed, than under exposed.
Light is allowed in to the camera to the photograph plate, film or sensor through a quickly opening and closing door called the shutter. The size of the hole which is revealed by the shutter is known as the aperture, and is measured in F-Stops, such as F1.8, F4.5, F11 etc. Where, confusingly, the larger the F number the smaller the aperture is. Thus, F1.8 is quite a large aperture, and F11 is fairly small. A larger aperture, represented by a smaller F number, lets in more light than a smaller aperture.
The length of time for which the shutter remains open, letting light in through the aperture is often referred to as the shutter speed, and is measured in fractions of a second. Thus, a shutter speed of 500 implies that the aperture will be open for 1/500th of a second, while a shutter speed of 125 implies that the aperture will be open for 1/125th of a second. The longer the aperture remains open, the more light will enter.
How quickly the photographic plate, film or sensor reacts to the light reaching it through the aperture is known as the sensitivity of the plate, film or sensor and is measured in ISO or ASA units. The larger the ISO value, the quicker the plate, film or sensor will react to the light. Thus, a sensitivity of ASA or ISO 100 will react slower than a sensitivity of 200 or 400.
The aperture size, shutter speed and sensitivity, work together to determine the level of exposure that occurs when a picture is taken. Automatic camera settings will set these three values for you, so that the picture is properly exposed, and if it can not be properly exposed, will warn you. However, there are other effects connected with each of these three settings.
The higher the sensitivity of the photographic plate, film or sensor, the more grainy or noisy the photograph will be. Therefore, using the lowest possible sensitivity will give the best possible quality for the photograph. In order to use a low sensitivity, the subject must be as brightly lit as possible. For example a subject in bright sunshine or lit by powerful lamps or the use of a cameraflash gun.
The camera's aperture size governs the depth of the photograph. The smaller the aperture is, the deeper the field of focus. Using a large aperture size will result in only the subject being in focus, objects behind and in front of the subject will be blurred. Using a small aperture will allow objects behind and in front of the subject to also be in focus. The smaller the aperture size, the further behind and in front of the subject objects will remain in focus, and by extension the easier it will be to focus upon the subject.
The most noticeable effect of the shutter speed is in reducing motion blur and camerashake. When holding a camera, particularly one with a long lens every one will quiver their hand to a greater or lesser degree. When using a zoom lens, this quivering or camerashake is much more noticeable than when using a shorter or wider angle lens. If the camera is moved, even slightly while the shutter is open, the picture will be blurred. The more the camera moves while the shutter is open, the more blurring will occur. By using a fast shutter speed, the shutter is open for less time and as such less movement affect the photograph. Similarly, if the subject being photographed moves while the image is being taken, the resulting photograph will be blurred. Using a fast shutter speed of 1/500th of a second or faster enables photographs to be taken of action shots, such as footballers in mid-movement or in the air while heading the ball. The subject's movement being slower than the speed of the shutter opening and closing which appears to freeze the moment in time.
The best way to reduce camerashake is to use a tripod. If you can not use a tripod, try resting the camera on a firm surface, such as a wall, fence post or tree. It can not be over emphasised that using a tripod will result in better photographs as every one quivers ever so slightly when taking photographs. Even activating the shutter release on the camera can slightly jar the camera. To overcome this, many photographers use a camera with automatic frame advance or sequential shooting, whereby after activating the shutter release the camera takes multiple photographs until the shutter release mechanism is released. In this way, three images may be taken automatically, the first and last will often suffer from slight camerashake due to the action of operating the shutter release mechanism, while the second image will not. Research Photography
The Jurca MJ3 is a French single-seater sporting aircraft formed from the fuselage of the Jurca MJ2 Tempete with different wings attached, the new wings having an extended leading-edge inboard of the fence on each side and a redesigned tip shape. The Jurca MJ3 is powered by various flat-four engines of between 85 and 125 hp, the standard engine being the Continental C90 providing a cruising speed of 210 kmh. Research Jurca MJ3
The Sukhoi Su-17 (Fitter) is a Soviet single-seater variable-geometry ground-attack and counter air aircraft developed from the Su-7 and first flown in 1966, entering service in 1972. The Sukhoi SU-17M (Fitter-C) is powered by an NPO Saturn AL-21F-3 turbojet providing a top speed of Mach 2.09 and a range of 445 km typically. It is armed with two 30 mm 2NR-30 cannons in the wing roots and up to 4500 kg of disposable stores carried on eight hard points, two tandem pairs under the fuselage, one under each wing glove and one under the fence at each wing pivot point (in practice only 1000 kg of stores are carried). Research Su-17
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert
Abbreviations
Research Barrier
