View allAll Photos Tagged extensible
British Royal Navy version of the F-4 Phantom. Featured Rolls Royce Spey engines in a redesigned rear fuselage and an extra-long extensible nose gear oleo for increased angle of attack for takeoff from the smaller British carriers. Identifiable by the large bypass cooling doors on the rear fuselage for the Spey engines.
Taburete que incorpora un mecanismo de elevación de columna hidráulica de gas que permite adaptar su uso a la altura deseada por el usuario. Destaca por la comodidad de su respaldo y el toque de distinción que le confiere el embellecedor metálico cromado en la parte superior del asiento.
Pensada para espacios estrechos, la mesa Concept Minor incorpora un sistema de extensión mediante el desplazamiento frontal de las patas, pasando de un ancho de 52 cm a un cómodo ancho de 80 cm en posición abierta. Incorpora un cómodo sistema de rodaje en las ruedas para facilitar la apertura. Se fabrica en armazón metálico aluminio, cromado, blanco y negro, y encimera en vidrio de templado de 8 mm.
A small slow-moving lizard with a long extensible tongue and tail.It has protruding eyes that rotate independently, and has the ability to change body colour hence the name 'Chameleon' I always thought a chameleon changed colour to hide but have just recently found out it's in fact the way that they communicate with each other.
Kelletia kelletii feeds with an extensible muscular proboscis which can be extended from the head region during feeding. Food is ingested by a muscular sucking action of the proboscis and a rasping of the radula. The proboscis is capable of extending approximately twice the length of the whelk's shell; it is this extension which allows Kelletia kelletii to reach food items in depressions or within the substratum. Most of the scavenger feedings by Kelletia kelletii attract more than one individual. In one instance, 85 were clustered around and feeding on a dead sea bass, Paralabrax sp., off Point Loma.
Interaction with sea star
Kellet's whelk has been observed feeding together at the same time with the Giant sea star Pisaster giganteus on common food items and thus these two species are trophically interrelated. Pisaster giganteus also preys on Kelletia kelletii more often than any other motile gastropod, and yet the whelks do not appear to be eaten in proportion to their abundance or accessibility in studied localitions. The sea star appears to be a major predator of the whelk, even though Kelletia kelletii makes up less than 10% of the diet of the sea star] The whelk does not display an avoidance response in the presence of Pisaster giganteus. Coexistence between the two species is believed possible as long as Kelletia kelletii does not become a preferred prey of the asteroid. Usually these feeding convergences involved only a single sea star and two or three whelks.
These convergent feeding groups were not limited to Kelletia kelletii and Pisaster giganteus. Kelletia kelletii has also been observed feeding interspecifically with two other sea stars, Dermasterias imbricata and Pisaster brevispinus.
Life cycle.
Females and males aggregate seasonally for mating. Fertilization is internal. Kellet's whelks reproduce annually, with egg-laying restricted to late spring and summer (in March, April and May).] The snails form aggregations, with the average spawning cluster being about 15 to 20 snails. However, a few spawning aggregations contain between 200 and 300 individuals.
Kelletia kelletii is slow-growing, and slow to mature. Studies have suggested a growth rate of 0.3 to 0.4 inches (7 to 10 millimeters) per year until sexual maturity. Rosenthal (1970)[ reported onset of sexual maturity at c. 60 mm in shell length (defined as maximum shell length from the tip of the spire to the tip of the siphonal canal).[4] having reached sexual maturity, growth slows considerably and it has been suggested that it takes at least 20 years to reach 3.5 inches (9.0 centimeters).[5] In a year-long tagging study in southern California the majority of the 188 animals recaptured showed no growth at the end of the year.
Kellet's whelk commercial landings
Year
Weight
1979 1,958 pounds (0.888 t)
1980 645 pounds (0.293 t)
1981 860 pounds (0.39 t)
1982 550 pounds (0.25 t)
1983 1,265 pounds (0.574 t)
1984 8,032 pounds (3.643 t)
1985 7,098 pounds (3.220 t)
1986 1,680 pounds (0.76 t)
1987 1,216 pounds (0.552 t)
1988 142 pounds (0.064 t)
1989 1,033 pounds (0.469 t)
1990 1,621 pounds (0.735 t)
1991 1,983 pounds (0.899 t)
1992 1,584 pounds (0.718 t)
1993 4,590 pounds (2.08 t)
1994 39,513 pounds (17.923 t)
1995 29,959 pounds (13.589 t)
1996 20,391 pounds (9.249 t)
1997 18,453 pounds (8.370 t)
1998 29,698 pounds (13.471 t)
1999 43,779 pounds (19.858 t)
2000 42,716 pounds (19.376 t)
2001 41,039 pounds (18.615 t)
2002 53,563 pounds (24.296 t)
2003 79,248 pounds (35.946 t)
2004 71,304 pounds (32.343 t)
2005 105,764 pounds (47.974 t)
2006 191,177 pounds (86.716 t)
2007 172,201 pounds (78.109 t)
2008 160,696 pounds (72.890 t)[5]
2009 ?
2010 67.5 t[10]
2011 ?
2012 ?
Shells of Kellet's whelks have been found in archeological and paleontological sites in southern California.[5] The earliest recorded commercial landing data specific to Kellet's whelk dates back to 1979, but prior to this it may have been recorded as "miscellaneous mollusks" or "sea snails".[5] Landings data indicate an increased intake starting in 1993 at 4590 pounds (2 metric tons), with the highest landings in 2006 being 191,177 pounds (87 metric tons). This represents an over forty-fold increase in thirteen years.[5] Kellet's whelk landings have been reported at 24 ports from 1979 to 2008, with 80 percent of landings occurring at four ports.[5] The majority of landings (439,828 pounds, 200 metric tons in 2008) occurred at Santa Barbara, with approximately 40 percent of the total landings reported.[5] The other three top ports were Terminal Island, San Diego, and San Pedro.[5] Dana Point is also an important port.[10] Ex-vessel value from the 2008 commercial harvest of Kellet's whelks was approximately $132,700, with price per pound averaging $0.82 ($1.81 per kilogram).[5] Since 1979, the fishery's ex-vessel value has ranged from $94 (1988) to approximately $136,000 (2007) and the ex-vessel price has ranged from $0.24 per pound ($0.53 per kilogram) in 1981 to $0.88 per pound ($1.94 per kilogram) in 1992.[5] The average weight of a Kellet's whelk in a fishery is 150 g.[10]
The food-finding ability of Kelletia kelletii by distance chemoreception has, on more than one occasion, been a nuisance to spiny lobster fishermen in some areas off southern California.[3] These fishermen usually bait traps with dead fish in order to attract the spiny lobster Panulirus interruptus.[3] Many times, however, a single lobster trap is found to contain dozens of Kelletia kelletii which were attracted to the trap by the "scent" of the bait.[3] Since 1979, 89 percent of all harvested Kellet's whelks have been taken incidentally in lobster and crab traps when they enter to prey on bait or on injured crustaceans.[5] The other method of take is diving.[5] Commercial divers are required to have a commercial fishing license, and may only take whelks that are further than 1000 feet (305 meters) beyond the low tide mark, as the take of any snails is prohibited in the tidal invertebrate zone (Title 14, CCR, §123).[5] Recreational take of Kellet's whelk by hand is allowed (Title 14, CCR, §29.05) outside of the 1000 foot (305 meter) tidal invertebrate zone.[5] Except where prohibited in state marine reserves, state marine parks and state marine conservation areas the bag limit is 35 animals, with no closed season.[5] Ninety-nine percent of Kellet's whelks are used for human consumption., and are mainly sold in live fish markets.[5]
The fact that this species is slow-growing, slow to mature, and makes seasonal aggregations for mating, all mean that this recently targeted fishery species is vulnerable to overexploitation.[4] The Kelletia kelletii fishery has experienced a rapid increase in landings since 1995, prompting the California Department of Fish and Game to designate the species as an "emerging fishery" (California Regulatory Notice Register 2011 43-Z).[4] New commercial and recreational fishing regulations for Kellet's whelk were established in 2012.[11]
This is the Cave Shredder, a powerfull shredding machine used by the Power Miners.
Features:
- The torso can spin in 360 degrees through a gears system.
- The claw open and closes.
- 1-stud (:P) extensible chopper blades, which can spin through a system made using a rubber elastic piece.
I didn't post in Flickr because of the length... =(
ANDAMAN SEA (Dec. 13, 2021) A twin boom extensible crane (TBEC) lowers an 11-meter rigid-hull inflatable boat (RHIB) to launch position during boat operations aboard Independence-variant littoral combat ship USS Tulsa (LCS 16). Tulsa, part of Destroyer Squadron (DESRON) 7, is on a rotational deployment, operating in U.S. 7th Fleet to enhance interoperability with partners and serve as a ready-response force in support of a free and open Indo-Pacific region. (U.S. Navy photo by Mass Communication Specialist 1st Class Devin M. Langer)
La sencillez de lineas y el amplio abanico de medidas de este modelo son sus características principales. El armazón metálico se ofrece en acabados aluminio, blanco y negro, y la encimera es de cristal templado de 8 mm en todos los colores del muestrario y además una versión de cristal mate transparente.
Ampliable de 4 a 8 plazas gracias a su doble sistema de extensión.Mesa extensible mediante el desplazamiento del armazón. Es el sistema ideal para evitar que las patas de la mesa obstaculicen mientras se hace uso de ella. Dispone de dos extensibles de apertura automática fabricados a juego con la encimera en vidrio templado coloreado de 8mm de espesor. Dispone de varias opciones de acabado en las patas, aluminio, blanco, negro o cromado, y todos los acabados del muestrario para la encimera de cristal.
The painted frogfish grows up to 30 centimetres (12 in) long. Like other members of its family, it has a globulous, extensible body, with soft skin is covered with small dermal spinules. Its skin is covered partially with few, small, wart-like protuberances, some variably shaped, scab-like blotches and many small eye spots (ocelli) which look like sponges holes. Its large prognathous mouth allows it to consume prey its same size.
The coloring of the body is extremely variable because they always tend to match their living environments. Frogfishes have the capacity to change coloration and pigment pattern in few weeks. However, the dominant coloration goes from white to black, passing through a whole range of related nuances such as cream, pink, yellow, red, and brown, usually with circular eye spots darker than the background color and/or with saddles and blotches. Some specimens can easily be confused with Antennarius maculatus. These characteristics can help to separate the two close species: usually, A. maculatus has red or orange margins on all fins, and sometimes a spike of the saddle blotch starts posterior to the eye, numerous warts on the skin, andfew or no ocellis; A. pictus has also three eye spots on its caudal fin. Juveniles can have a dark background color with small yellow spots.
The first dorsal spine, the [illicium (fish anatomy)|illicium]], is modified and is used as a fishing rod. Its extremity is endowed with a characteristic esca (lure), which looks like a small fish with a pinkish to brownish coloration. The illicium is twice the length of the second dorsal spine and its often darkly banded. The second dorsal spine is practically straight and is mobile, and the third one is bent towards the back of the body; both are membranously attached to the head. They are well separated from each other and from the dorsal fin.
The pectoral fins are angled and help, with the pelvic fins, to move the frogfish on the bottom and to keep a stable position for ambush.
This fully manual camera with a Xenar-Schneider lens was used during the cold war by spies because it was easy to conceal. Lots of accessories were available to make pictures without raising the awareness of the target (such as a right angle viewfinder). It can also takes many pictures at a very rapid speed (a bonus for spies). And last but not least, it is extremely rugged and solid (James Bond enjoys this feature very much).
Earlier models were used by the Luftwaffe during WWII.
Some say the quality of its pictures are as good as a leica's. I haven't tried yet because the film cartridge is missing (must find one on the internet). What is quite interesting is that it uses regular 35mm but in 24 X 24 frames only. So, the pictures are square (and you can put more on one film - spies like that!).
I am eager to use it! I have never used a fully manual camera before...
Serial #: D-110045
ROBOT-STAR I 4th version
Long advance knob
Years manufactured : 1954-1960
Series letter : "D"
Square format : 24×24 ,35mm film
Motor capacity : 48 exposures
Shutter speeds : B, 1/2, 1/5, 1/10, 1/25, 1/50, 1/100, 1/250, 1/500 sec
Rewinding system : extensible knob
Attachment for accessories : on the hood
Flash contact : X and M
Clear Viewfinder : +right angle Viewfinder
Mount : 26mm screw mount
Weight : 500g
Outside finish : chrome/black finish
Production : 560 approx.
Cassettes for film : Commercially available cartridge; "N" Winder
Soil profile: A representative soil profile of Arol fine sandy loam. The subsoil is very dense, and it is underlain by weakly cemented
tuffaceous material at a depth of about 90 centimeters. (Soil Survey of Fayette County, Texas; by Dennis D. Ressel and Samuel E. Brown, Jr., Natural Resources Conservation Service)
The Arol series consists of moderately deep, moderately well drained soils that formed in clayey residuum weathered from tuffaceous sandstone and siltstone of the Catahoula formation of Miocene age. These nearly level to gently sloping soils are on broad, upland ridges. Slope ranges from 0 to 5 percent. Mean annual precipitation is about 889 to 1232 mm (35 to 49 in) and the mean annual air temperature is about 18.4 to 21.1 degrees C (65 to 70 degrees F).
TAXONOMIC CLASS: Fine, smectitic, thermic Udic Paleustalfs
Note: These soils do not have an aquic moisture regime. Classification change from Typic Albaqualfs is due to interpretation that the low chroma matrix is due to organic matter accumulations in conjunction with gray colored parent material. Field observations, water table studies from Texas A&M University, landscape position and climate indicate the soil is typically not saturated long enough to be reduced in most years. Arol soils were formerly included in the Wilson series.
Depth of solum: 61 to 94 cm (24 to 37 in), moderately deep
Depth to argillic horizon: 13 to 20 cm (5 to 8 in)
Depth to abrupt textural change: 13 to 20 cm (5 to 8 in)
Depth to redoximorphic features: 13 to 46 cm (5 to 18 in)
Depth to paralithic material: 61 to 94 cm (24 to 37 in)
Depth to paralithic contact: 61 to 94 cm (20 to 40 in)
Rock fragments: Less than 5 percent (by volume) sandstone gravels
Coefficient of Linear Extensibility (COLE):May exceed 0.07 in the Bt subhorizons of some pedons, but the potential linear extensibility is less than 6 cm (2.4 in)
Particle size control section (weighted average)
Clay content: 35 to 45 percent in particle size control section
Rock fragments: Less than 5 percent (by volume) sandstone gravels
USE AND VEGETATION: Used mainly as pastureland. Large acreages were once planted to cotton and corn, but are now idle or in low quality pastures of threeawn grasses and annuals. Improved pastures are mainly coastal bermudagrass. Native grasses are little bluestem, indiangrass, switchgrass, big bluestem, and sideoats grama with scattered post oak trees.
DISTRIBUTION AND EXTENT: Land Resource Region J - Southwestern Prairies Cotton and Forage Region. Southeastern Claypan area of Texas (MLRA 87A). The series is moderately extensive.
For additional information about the survey area, visit:
www.nrcs.usda.gov/Internet/FSE_MANUSCRIPTS/texas/TX149/0/...
For a detailed soil description, visit:
soilseries.sc.egov.usda.gov/OSD_Docs/A/AROL.html
For acreage and geographic distribution, visit:
Prototype of the Mercury, an infinitely extensible, open camera system that I developed over the past two years, with some help from others. This one is shown configured for 6x9 medium format.
La mesa Camel auna modernidad y tradición en un diseño en el que el valor añadido lo incorpora un cajón de gran capacidad con sistema de freno integrado
Disciplines / Task Styles:
- F1A (Gliders) - seniors
- F1B (Model Aircraft with Extensible Motors Wakefield) - seniors
- F1C (Power Model Aircraft) - seniors
Place: Moncontour (France)
Dates: 03 Aug to 10 Aug 2013
Photo by Cenny Breeman
Disciplines / Task Styles:
- F1A (Gliders) - seniors
- F1B (Model Aircraft with Extensible Motors Wakefield) - seniors
- F1C (Power Model Aircraft) - seniors
Place: Moncontour (France)
Dates: 03 Aug to 10 Aug 2013
Photo by Cenny Breeman
The perfect plow for removing snow in tight places this plow goes from 6 to 10 feet and includes standard anti shock wings.
For details write to: info@cotech.qc.ca
This dragonfly is carrying its eggs
A dragonfly is an insect belonging to the order Odonata, infraorder Anisoptera (from Greek ἄνισος anisos, "unequal" and πτερόν pteron, "wing", because the hindwing is broader than the forewing). Adult dragonflies are characterized by large, multifaceted eyes, two pairs of strong, transparent wings, sometimes with coloured patches, and an elongated body. Dragonflies can be mistaken for the related group, damselflies (Zygoptera), which are similar in structure, though usually lighter in build; however, the wings of most dragonflies are held flat and away from the body, while damselflies hold their wings folded at rest, along or above the abdomen. Dragonflies are agile fliers, while damselflies have a weaker, fluttery flight. Many dragonflies have brilliant iridescent or metallic colours produced by structural colouration, making them conspicuous in flight. An adult dragonfly's compound eyes have nearly 24,000 ommatidia each.
Fossils of very large dragonfly-like insects, sometimes called griffinflies, are found from 325 million years ago (Mya) in Upper Carboniferous rocks; these had wingspans up to about 750 mm (30 in), but were only distant ancestors, not true dragonflies. About 3,000 extant species of true dragonfly are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threatens dragonfly populations around the world.
Dragonflies are predators, both in their aquatic nymphs stage (also known as naiads) and as adults. In some species, the nymphal stage lasts for up to five years, and the adult stage may be as long as ten weeks, but most species have an adult lifespan in the order of five weeks or less, and some survive for only a few days. They are fast, agile fliers, sometimes migrating across oceans, and often live near water. They have a uniquely complex mode of reproduction involving indirect insemination, delayed fertilization, and sperm competition. During mating, the male grasps the female at the back of the head, and the female curls her abdomen under her body to pick up sperm from the male's secondary genitalia at the front of his abdomen, forming the "heart" or "wheel" posture.
Dragonflies are represented in human culture on artefacts such as pottery, rock paintings, statues and Art Nouveau jewellery. They are used in traditional medicine in Japan and China, and caught for food in Indonesia. They are symbols of courage, strength, and happiness in Japan, but seen as sinister in European folklore. Their bright colours and agile flight are admired in the poetry of Lord Tennyson and the prose of H. E. Bates.
Evolution
Dragonflies and their relatives are similar in structure to an ancient group, meganisoptera, from the 325 Mya Upper Carboniferous of Europe, a group that included the largest insect that ever lived, Meganeuropsis permiana from the Early Permian, with a wingspan around 750 mm (30 in);. Known informally as "griffinflies", their fossil record ends with the Permian–Triassic extinction event (about 247 Mya). The Protanisoptera, another ancestral group that lacks certain wing vein characters found in modern Odonata, lived from the Early to Late Permian age until the end Permian event, and are known from fossil wings from current-day United States, Russia, and Australia, suggesting they might have been cosmopolitan in distribution. While both of those groups are sometimes referred to as "giant dragonflies", in fact true dragonflies/odonata are more modern insects that had not evolved yet.
Modern dragonflies do retain some traits of their distant predecessors, and are in a group known as palaeoptera, ancient-winged. They, like the gigantic pre-dinosaur griffinflies, lack the ability to fold their wings up against their bodies in the way modern insects do, although some evolved their own different way to do so. The forerunners of modern Odonata are included in a clade called the Panodonata, which include the basal Zygoptera (damselflies) and the Anisoptera (true dragonflies). Today, some 3,000 species are extant around the world.
The relationships of anisopteran families are not fully resolved as of 2013, but all the families are monophyletic except the Corduliidae; the Gomphidae are a sister taxon to all other Anisoptera, the Austropetaliidae are sister to the Aeshnoidea, and the Chlorogomphidae are sister to a clade that includes the Synthemistidae and Libellulidae. On the cladogram, dashed lines indicate unresolved relationships; English names are given (in parentheses)
Distribution and diversity
About 3,012 species of dragonflies were known in 2010; these are classified into 348 genera in 11 families. The distribution of diversity within the biogeographical regions are summarized below (the world numbers are not ordinary totals, as overlaps in species occur).
Dragonflies live on every continent except Antarctica. In contrast to the damselflies (Zygoptera), which tend to have restricted distributions, some genera and species are spread across continents. For example, the blue-eyed darner Rhionaeschna multicolor lives all across North America, and in Central America; emperors Anax live throughout the Americas from as far north as Newfoundland to as far south as Bahia Blanca in Argentina, across Europe to central Asia, North Africa, and the Middle East. The globe skimmer Pantala flavescens is probably the most widespread dragonfly species in the world; it is cosmopolitan, occurring on all continents in the warmer regions. Most Anisoptera species are tropical, with far fewer species in temperate regions.
Some dragonflies, including libellulids and aeshnids, live in desert pools, for example in the Mojave Desert, where they are active in shade temperatures between 18 and 45 °C (64.4 to 113 °F); these insects were able to survive body temperatures above the thermal death point of insects of the same species in cooler places.
Dragonflies live from sea level up to the mountains, decreasing in species diversity with altitude. Their altitudinal limit is about 3700 m, represented by a species of Aeshna in the Pamirs.
Dragonflies become scarce at higher latitudes. They are not native to Iceland, but individuals are occasionally swept in by strong winds, including a Hemianax ephippiger native to North Africa, and an unidentified darter species. In Kamchatka, only a few species of dragonfly including the treeline emerald Somatochlora arctica and some aeshnids such as Aeshna subarctica are found, possibly because of the low temperature of the lakes there. The treeline emerald also lives in northern Alaska, within the Arctic Circle, making it the most northerly of all dragonflies.
General description
Dragonflies (suborder Anisoptera) are heavy-bodied, strong-flying insects that hold their wings horizontally both in flight and at rest. By contrast, damselflies (suborder Zygoptera) have slender bodies and fly more weakly; most species fold their wings over the abdomen when stationary, and the eyes are well separated on the sides of the head.
An adult dragonfly has three distinct segments, the head, thorax, and abdomen, as in all insects. It has a chitinous exoskeleton of hard plates held together with flexible membranes. The head is large with very short antennae. It is dominated by the two compound eyes, which cover most of its surface. The compound eyes are made up of ommatidia, the numbers being greater in the larger species. Aeshna interrupta has 22650 ommatidia of two varying sizes, 4500 being large. The facets facing downward tend to be smaller. Petalura gigantea has 23890 ommatidia of just one size. These facets provide complete vision in the frontal hemisphere of the dragonfly. The compound eyes meet at the top of the head (except in the Petaluridae and Gomphidae, as also in the genus Epiophlebia). Also, they have three simple eyes or ocelli. The mouthparts are adapted for biting with a toothed jaw; the flap-like labrum, at the front of the mouth, can be shot rapidly forward to catch prey. The head has a system for locking it in place that consists of muscles and small hairs on the back of the head that grip structures on the front of the first thoracic segment. This arrester system is unique to the Odonata, and is activated when feeding and during tandem flight.
The thorax consists of three segments as in all insects. The prothorax is small and is flattened dorsally into a shield-like disc, which has two transverse ridges. The mesothorax and metathorax are fused into a rigid, box-like structure with internal bracing, and provide a robust attachment for the powerful wing muscles inside. The thorax bears two pairs of wings and three pairs of legs. The wings are long, veined, and membranous, narrower at the tip and wider at the base. The hindwings are broader than the forewings and the venation is different at the base. The veins carry haemolymph, which is analogous to blood in vertebrates, and carries out many similar functions, but which also serves a hydraulic function to expand the body between nymphal stages (instars) and to expand and stiffen the wings after the adult emerges from the final nymphal stage. The leading edge of each wing has a node where other veins join the marginal vein, and the wing is able to flex at this point. In most large species of dragonflies, the wings of females are shorter and broader than those of males. The legs are rarely used for walking, but are used to catch and hold prey, for perching, and for climbing on plants. Each has two short basal joints, two long joints, and a three-jointed foot, armed with a pair of claws. The long leg joints bear rows of spines, and in males, one row of spines on each front leg is modified to form an "eyebrush", for cleaning the surface of the compound eye.
The abdomen is long and slender and consists of 10 segments. Three terminal appendages are on segment 10; a pair of superiors (claspers) and an inferior. The second and third segments are enlarged, and in males, on the underside of the second segment has a cleft, forming the secondary genitalia consisting of the lamina, hamule, genital lobe, and penis. There are remarkable variations in the presence and the form of the penis and the related structures, the flagellum, cornua, and genital lobes. Sperm is produced at the 9th segment, and is transferred to the secondary genitalia prior to mating. The male holds the female behind the head using a pair of claspers on the terminal segment. In females, the genital opening is on the underside of the eighth segment, and is covered by a simple flap (vulvar lamina) or an ovipositor, depending on species and the method of egg-laying. Dragonflies having simple flaps shed the eggs in water, mostly in flight. Dragonflies having ovipositors use them to puncture soft tissues of plants and place the eggs singly in each puncture they make.
Dragonfly nymphs vary in form with species, and are loosely classed into claspers, sprawlers, hiders, and burrowers. The first instar is known as a prolarva, a relatively inactive stage from which it quickly moults into the more active nymphal form. The general body plan is similar to that of an adult, but the nymph lacks wings and reproductive organs. The lower jaw has a huge, extensible labium, armed with hooks and spines, which is used for catching prey. This labium is folded under the body at rest and struck out at great speed by hydraulic pressure created by the abdominal muscles. Whereas damselfly nymphs have three feathery external gills, dragonfly nymphs have internal gills, located around the fourth and fifth abdominal segments. Water is pumped in and out of the abdomen through an opening at the tip. The naiads of some clubtails (Gomphidae) that burrow into the sediment, have a snorkel-like tube at the end of the abdomen enabling them to draw in clean water while they are buried in mud. Naiads can forcefully expel a jet of water to propel themselves with great rapidity.
Colouration
Many adult dragonflies have brilliant iridescent or metallic colours produced by structural colouration, making them conspicuous in flight. Their overall colouration is often a combination of yellow, red, brown, and black pigments, with structural colours. Blues are typically created by microstructures in the cuticle that reflect blue light. Greens often combine a structural blue with a yellow pigment. Freshly emerged adults, known as tenerals, are often pale-coloured and obtain their typical colours after a few days, some have their bodies covered with a pale blue, waxy powderiness called pruinosity; it wears off when scraped during mating, leaving darker areas.
Some dragonflies, such as the green darner, Anax junius, have a noniridescent blue that is produced structurally by scatter from arrays of tiny spheres in the endoplasmic reticulum of epidermal cells underneath the cuticle.
The wings of dragonflies are generally clear, apart from the dark veins and pterostigmata. In the chasers (Libellulidae), however, many genera have areas of colour on the wings: for example, groundlings (Brachythemis) have brown bands on all four wings, while some scarlets (Crocothemis) and dropwings (Trithemis) have bright orange patches at the wing bases. Some aeshnids such as the brown hawker (Aeshna grandis) have translucent, pale yellow wings.
Dragonfly nymphs are usually a well-camouflaged blend of dull brown, green, and grey.
Biology
Ecology
Dragonflies and damselflies are predatory both in the aquatic nymphal and adult stages. Nymphs feed on a range of freshwater invertebrates and larger ones can prey on tadpoles and small fish. Adults capture insect prey in the air, making use of their acute vision and highly controlled flight. The mating system of dragonflies is complex, and they are among the few insect groups that have a system of indirect sperm transfer along with sperm storage, delayed fertilization, and sperm competition.
Adult males vigorously defend territories near water; these areas provide suitable habitat for the nymphs to develop, and for females to lay their eggs. Swarms of feeding adults aggregate to prey on swarming prey such as emerging flying ants or termites.
Dragonflies as a group occupy a considerable variety of habitats, but many species, and some families, have their own specific environmental requirements. Some species prefer flowing waters, while others prefer standing water. For example, the Gomphidae (clubtails) live in running water, and the Libellulidae (skimmers) live in still water. Some species live in temporary water pools and are capable of tolerating changes in water level, desiccation, and the resulting variations in temperature, but some genera such as Sympetrum (darters) have eggs and nymphs that can resist drought and are stimulated to grow rapidly in warm, shallow pools, also often benefiting from the absence of predators there. Vegetation and its characteristics including submerged, floating, emergent, or waterside are also important. Adults may require emergent or waterside plants to use as perches; others may need specific submerged or floating plants on which to lay eggs. Requirements may be highly specific, as in Aeshna viridis (green hawker), which lives in swamps with the water-soldier, Stratiotes aloides. The chemistry of the water, including its trophic status (degree of enrichment with nutrients) and pH can also affect its use by dragonflies. Most species need moderate conditions, not too eutrophic, not too acidic; a few species such as Sympetrum danae (black darter) and Libellula quadrimaculata (four-spotted chaser) prefer acidic waters such as peat bogs, while others such as Libellula fulva (scarce chaser) need slow-moving, eutrophic waters with reeds or similar waterside plants.
Behaviour
Many dragonflies, particularly males, are territorial. Some defend a territory against others of their own species, some against other species of dragonfly and a few against insects in unrelated groups. A particular perch may give a dragonfly a good view over an insect-rich feeding ground; males of many species such as the Pachydiplax longipennis (blue dasher) jostle other dragonflies to maintain the right to alight there. Defending a breeding territory is common among male dragonflies, especially in species that congregate around ponds. The territory contains desirable features such as a sunlit stretch of shallow water, a special plant species, or the preferred substrate for egg-laying. The territory may be small or large, depending on its quality, the time of day, and the number of competitors, and may be held for a few minutes or several hours. Dragonflies including Tramea lacerata (black saddlebags) may notice landmarks that assist in defining the boundaries of the territory. Landmarks may reduce the costs of territory establishment, or might serve as a spatial reference. Some dragonflies signal ownership with striking colours on the face, abdomen, legs, or wings. The Plathemis lydia (common whitetail) dashes towards an intruder holding its white abdomen aloft like a flag. Other dragonflies engage in aerial dogfights or high-speed chases. A female must mate with the territory holder before laying her eggs. There is also conflict between the males and females. Females may sometimes be harassed by males to the extent that it affects their normal activities including foraging and in some dimorphic species females have evolved multiple forms with some forms appearing deceptively like males. In some species females have evolved behavioural responses such as feigning death to escape the attention of males. Similarly, selection of habitat by adult dragonflies is not random, and terrestrial habitat patches may be held for up to 3 months. A species tightly linked to its birth site utilises a foraging area that is several orders of magnitude larger than the birth site.
Reproduction
Mating in dragonflies is a complex, precisely choreographed process. First, the male has to attract a female to his territory, continually driving off rival males. When he is ready to mate, he transfers a packet of sperm from his primary genital opening on segment 9, near the end of his abdomen, to his secondary genitalia on segments 2–3, near the base of his abdomen. The male then grasps the female by the head with the claspers at the end of his abdomen; the structure of the claspers varies between species, and may help to prevent interspecific mating. The pair flies in tandem with the male in front, typically perching on a twig or plant stem. The female then curls her abdomen downwards and forwards under her body to pick up the sperm from the male's secondary genitalia, while the male uses his "tail" claspers to grip the female behind the head: this distinctive posture is called the "heart" or "wheel"; the pair may also be described as being "in cop".
Egg-laying (ovipositing) involves not only the female darting over floating or waterside vegetation to deposit eggs on a suitable substrate, but also the male hovering above her or continuing to clasp her and flying in tandem. The male attempts to prevent rivals from removing his sperm and inserting their own, something made possible by delayed fertilisation and driven by sexual selection. If successful, a rival male uses his penis to compress or scrape out the sperm inserted previously; this activity takes up much of the time that a copulating pair remains in the heart posture. Flying in tandem has the advantage that less effort is needed by the female for flight and more can be expended on egg-laying, and when the female submerges to deposit eggs, the male may help to pull her out of the water.
Egg-laying takes two different forms depending on the species. The female in some families has a sharp-edged ovipositor with which she slits open a stem or leaf of a plant on or near the water, so she can push her eggs inside. In other families such as clubtails (Gomphidae), cruisers (Macromiidae), emeralds (Corduliidae), and skimmers (Libellulidae), the female lays eggs by tapping the surface of the water repeatedly with her abdomen, by shaking the eggs out of her abdomen as she flies along, or by placing the eggs on vegetation. In a few species, the eggs are laid on emergent plants above the water, and development is delayed until these have withered and become immersed.
Life cycle
Dragonflies are hemimetabolous insects; they do not have a pupal stage and undergo an incomplete metamorphosis with a series of nymphal stages from which the adult emerges. Eggs laid inside plant tissues are usually shaped like grains of rice, while other eggs are the size of a pinhead, ellipsoidal, or nearly spherical. A clutch may have as many as 1500 eggs, and they take about a week to hatch into aquatic nymphs or naiads which moult between six and 15 times (depending on species) as they grow. Most of a dragonfly's life is spent as a nymph, beneath the water's surface. The nymph extends its hinged labium (a toothed mouthpart similar to a lower mandible, which is sometimes termed as a "mask" as it is normally folded and held before the face) that can extend forward and retract rapidly to capture prey such as mosquito larvae, tadpoles, and small fish. They breathe through gills in their rectum, and can rapidly propel themselves by suddenly expelling water through the anus. Some naiads, such as the later stages of Antipodophlebia asthenes, hunt on land.
The nymph stage of dragonflies lasts up to five years in large species, and between two months and three years in smaller species. When the naiad is ready to metamorphose into an adult, it stops feeding and makes its way to the surface, generally at night. It remains stationary with its head out of the water, while its respiration system adapts to breathing air, then climbs up a reed or other emergent plant, and moults (ecdysis). Anchoring itself firmly in a vertical position with its claws, its skin begins to split at a weak spot behind the head. The adult dragonfly crawls out of its nymph skin, the exuvia, arching backwards when all but the tip of its abdomen is free, to allow its exoskeleton to harden. Curling back upwards, it completes its emergence, swallowing air, which plumps out its body, and pumping haemolymph into its wings, which causes them to expand to their full extent.
Dragonflies in temperate areas can be categorized into two groups, an early group and a later one. In any one area, individuals of a particular "spring species" emerge within a few days of each other. The springtime darner (Basiaeschna janata), for example, is suddenly very common in the spring, but disappears a few weeks later and is not seen again until the following year. By contrast, a "summer species" emerges over a period of weeks or months, later in the year. They may be seen on the wing for several months, but this may represent a whole series of individuals, with new adults hatching out as earlier ones complete their lifespans.
Sex ratios
The sex ratio of male to female dragonflies varies both temporally and spatially. Adult dragonflies have a high male-biased ratio at breeding habitats. The male-bias ratio has contributed partially to the females using different habitats to avoid male harassment. As seen in Hine's emerald dragonfly (Somatochlora hineana), male populations use wetland habitats, while females use dry meadows and marginal breeding habitats, only migrating to the wetlands to lay their eggs or to find mating partners. Unwanted mating is energetically costly for females because it affects the amount of time that they are able to spend foraging.
Flight
Dragonflies are powerful and agile fliers, capable of migrating across the sea, moving in any direction, and changing direction suddenly. In flight, the adult dragonfly can propel itself in six directions: upward, downward, forward, backward, to left and to right. They have four different styles of flight: A number of flying modes are used that include counter-stroking, with forewings beating 180° out of phase with the hindwings, is used for hovering and slow flight. This style is efficient and generates a large amount of lift; phased-stroking, with the hindwings beating 90° ahead of the forewings, is used for fast flight. This style creates more thrust, but less lift than counter-stroking; synchronised-stroking, with forewings and hindwings beating together, is used when changing direction rapidly, as it maximises thrust; and gliding, with the wings held out, is used in three situations: free gliding, for a few seconds in between bursts of powered flight; gliding in the updraft at the crest of a hill, effectively hovering by falling at the same speed as the updraft; and in certain dragonflies such as darters, when "in cop" with a male, the female sometimes simply glides while the male pulls the pair along by beating his wings.
The wings are powered directly, unlike most families of insects, with the flight muscles attached to the wing bases. Dragonflies have a high power/weight ratio, and have been documented accelerating at 4 G linearly and 9 G in sharp turns while pursuing prey.
Dragonflies generate lift in at least four ways at different times, including classical lift like an aircraft wing; supercritical lift with the wing above the critical angle, generating high lift and using very short strokes to avoid stalling; and creating and shedding vortices. Some families appear to use special mechanisms, as for example the Libellulidae which take off rapidly, their wings beginning pointed far forward and twisted almost vertically. Dragonfly wings behave highly dynamically during flight, flexing and twisting during each beat. Among the variables are wing curvature, length and speed of stroke, angle of attack, forward/back position of wing, and phase relative to the other wings.
Flight speed
Old and unreliable claims are made that dragonflies such as the southern giant darner can fly up to 97 km/h (60 mph). However, the greatest reliable flight speed records are for other types of insects. In general, large dragonflies like the hawkers have a maximum speed of 36–54 km/h (22–34 mph) with average cruising speed of about 16 km/h (9.9 mph). Dragonflies can travel at 100 body-lengths per second in forward flight, and three lengths per second backwards.
Motion camouflage
n high-speed territorial battles between male Australian emperors (Hemianax papuensis), the fighting dragonflies adjust their flight paths to appear stationary to their rivals, minimizing the chance of being detected as they approach.[a] To achieve the effect, the attacking dragonfly flies towards his rival, choosing his path to remain on a line between the rival and the start of his attack path. The attacker thus looms larger as he closes on the rival, but does not otherwise appear to move. Researchers found that six of 15 encounters involved motion camouflage.
Temperature control
The flight muscles need to be kept at a suitable temperature for the dragonfly to be able to fly. Being cold-blooded, they can raise their temperature by basking in the sun. Early in the morning, they may choose to perch in a vertical position with the wings outstretched, while in the middle of the day, a horizontal stance may be chosen. Another method of warming up used by some larger dragonflies is wing-whirring, a rapid vibration of the wings that causes heat to be generated in the flight muscles. The green darner (Anax junius) is known for its long-distance migrations, and often resorts to wing-whirring before dawn to enable it to make an early start.
Becoming too hot is another hazard, and a sunny or shady position for perching can be selected according to the ambient temperature. Some species have dark patches on the wings which can provide shade for the body, and a few use the obelisk posture to avoid overheating. This behaviour involves doing a "handstand", perching with the body raised and the abdomen pointing towards the sun, thus minimising the amount of solar radiation received. On a hot day, dragonflies sometimes adjust their body temperature by skimming over a water surface and briefly touching it, often three times in quick succession. This may also help to avoid desiccation.
Feeding
Adult dragonflies hunt on the wing using their exceptionally acute eyesight and strong, agile flight. They are almost exclusively carnivorous, eating a wide variety of insects ranging from small midges and mosquitoes to butterflies, moths, damselflies, and smaller dragonflies. A large prey item is subdued by being bitten on the head and is carried by the legs to a perch. Here, the wings are discarded and the prey usually ingested head first. A dragonfly may consume as much as a fifth of its body weight in prey per day. Dragonflies are also some of the insect world's most efficient hunters, catching up to 95% of the prey they pursue.
The nymphs are voracious predators, eating most living things that are smaller than they are. Their staple diet is mostly bloodworms and other insect larvae, but they also feed on tadpoles and small fish. A few species, especially those that live in temporary waters, are likely to leave the water to feed. Nymphs of Cordulegaster bidentata sometimes hunt small arthropods on the ground at night, while some species in the Anax genus have even been observed leaping out of the water to attack and kill full-grown tree frogs.
Eyesight
Dragonfly vision is thought to be like slow motion for humans. Dragonflies see faster than we do; they see around 200 images per second. A dragonfly can see in 360 degrees, and nearly 80 percent of the insect's brain is dedicated to its sight.
Predators
Although dragonflies are swift and agile fliers, some predators are fast enough to catch them. These include falcons such as the American kestrel, the merlin, and the hobby; nighthawks, swifts, flycatchers and swallows also take some adults; some species of wasps, too, prey on dragonflies, using them to provision their nests, laying an egg on each captured insect. In the water, various species of ducks and herons eat dragonfly nymphs and they are also preyed on by newts, frogs, fish, and water spiders. Amur falcons, which migrate over the Indian Ocean at a period that coincides with the migration of the globe skimmer dragonfly, Pantala flavescens, may actually be feeding on them while on the wing.
Parasites
Dragonflies are affected by three major groups of parasites: water mites, gregarine protozoa, and trematode flatworms (flukes). Water mites, Hydracarina, can kill smaller dragonfly nymphs, and may also be seen on adults. Gregarines infect the gut and may cause blockage and secondary infection. Trematodes are parasites of vertebrates such as frogs, with complex life cycles often involving a period as a stage called a cercaria in a secondary host, a snail. Dragonfly nymphs may swallow cercariae, or these may tunnel through a nymph's body wall; they then enter the gut and form a cyst or metacercaria, which remains in the nymph for the whole of its development. If the nymph is eaten by a frog, the amphibian becomes infected by the adult or fluke stage of the trematode.
Dragonflies and humans
Conservation
Most odonatologists live in temperate areas and the dragonflies of North America and Europe have been the subject of much research. However, the majority of species live in tropical areas and have been little studied. With the destruction of rainforest habitats, many of these species are in danger of becoming extinct before they have even been named. The greatest cause of decline is forest clearance with the consequent drying up of streams and pools which become clogged with silt. The damming of rivers for hydroelectric schemes and the drainage of low-lying land has reduced suitable habitat, as has pollution and the introduction of alien species.
In 1997, the International Union for Conservation of Nature set up a status survey and conservation action plan for dragonflies. This proposes the establishment of protected areas around the world and the management of these areas to provide suitable habitat for dragonflies. Outside these areas, encouragement should be given to modify forestry, agricultural, and industrial practices to enhance conservation. At the same time, more research into dragonflies needs to be done, consideration should be given to pollution control and the public should be educated about the importance of biodiversity.
Habitat degradation has reduced dragonfly populations across the world, for example in Japan. Over 60% of Japan's wetlands were lost in the 20th century, so its dragonflies now depend largely on rice fields, ponds, and creeks. Dragonflies feed on pest insects in rice, acting as a natural pest control. Dragonflies are steadily declining in Africa, and represent a conservation priority.
The dragonfly's long lifespan and low population density makes it vulnerable to disturbance, such as from collisions with vehicles on roads built near wetlands. Species that fly low and slow may be most at risk.
Dragonflies are attracted to shiny surfaces that produce polarization which they can mistake for water, and they have been known to aggregate close to polished gravestones, solar panels, automobiles, and other such structures on which they attempt to lay eggs. These can have a local impact on dragonfly populations; methods of reducing the attractiveness of structures such as solar panels are under experimentation.
In culture
A blue-glazed faience dragonfly amulet was found by Flinders Petrie at Lahun, from the Late Middle Kingdom of ancient Egypt.
Many Native American tribes consider dragonflies to be medicine animals that had special powers. For example, the southwestern tribes, including the Pueblo, Hopi, and Zuni, associated dragonflies with transformation. They referred to dragonflies as "snake doctors" because they believed dragonflies followed snakes into the ground and healed them if they were injured. For the Navajo, dragonflies symbolize pure water. Often stylized in a double-barred cross design, dragonflies are a common motif in Zuni pottery, as well as Hopi rock art and Pueblo necklaces.: 20–26
As a seasonal symbol in Japan, the dragonflies are associated with season of autumn. In Japan, they are symbols of rebirth, courage, strength, and happiness. They are also depicted frequently in Japanese art and literature, especially haiku poetry. Japanese children catch large dragonflies as a game, using a hair with a small pebble tied to each end, which they throw into the air. The dragonfly mistakes the pebbles for prey, gets tangled in the hair, and is dragged to the ground by the weight.: 38
In Chinese culture, dragonflies symbolize both change and instability. They are also symbols in the Chinese practices of Feng Shui, where placements of dragonfly statues and artwork in parts of a home or office are believed to bring new insights and positive changes.
In both China and Japan, dragonflies have been used in traditional medicine. In Indonesia, adult dragonflies are caught on poles made sticky with birdlime, then fried in oil as a delicacy.
Images of dragonflies are common in Art Nouveau, especially in jewellery designs. They have also been used as a decorative motif on fabrics and home furnishings. Douglas, a British motorcycle manufacturer based in Bristol, named its innovatively designed postwar 350-cc flat-twin model the Dragonfly.
Among the classical names of Japan are Akitsukuni (秋津国), Akitsushima (秋津島), Toyo-akitsushima (豊秋津島). Akitsu is an old word for dragonfly, so one interpretation of Akitsushima is "Dragonfly Island". This is attributed to a legend in which Japan's mythical founder, Emperor Jimmu, was bitten by a mosquito, which was then eaten by a dragonfly.
In Europe, dragonflies have often been seen as sinister. Some English vernacular names, such as "horse-stinger", "devil's darning needle", and "ear cutter", link them with evil or injury. Swedish folklore holds that the devil uses dragonflies to weigh people's souls.: 25–27 The Norwegian name for dragonflies is Øyenstikker ("eye-poker"), and in Portugal, they are sometimes called tira-olhos ("eyes-snatcher"). They are often associated with snakes, as in the Welsh name gwas-y-neidr, "adder's servant". The Southern United States terms "snake doctor" and "snake feeder" refer to a folk belief that dragonflies catch insects for snakes or follow snakes around and stitch them back together if they are injured. Interestingly, the Hungarian name for dragonfly is szitakötő ("sieve-knitter").
The watercolourist Moses Harris (1731–1785), known for his The Aurelian or natural history of English insects (1766), published in 1780, the first scientific descriptions of several Odonata including the banded demoiselle, Calopteryx splendens. He was the first English artist to make illustrations of dragonflies accurate enough to be identified to species (Aeshna grandis at top left of plate illustrated), though his rough drawing of a nymph (at lower left) with the mask extended appears to be plagiarised.[b]
More recently, dragonfly watching has become popular in America as some birdwatchers seek new groups to observe.
In heraldry, like other winged insects, the dragonfly is typically depicted tergiant (with its back facing the viewer), with its head to chief.
In poetry and literature
Lafcadio Hearn wrote in his 1901 book A Japanese Miscellany that Japanese poets had created dragonfly haiku "almost as numerous as are the dragonflies themselves in the early autumn." The poet Matsuo Bashō (1644–1694) wrote haiku such as "Crimson pepper pod / add two pairs of wings, and look / darting dragonfly", relating the autumn season to the dragonfly. Hori Bakusui (1718–1783) similarly wrote "Dyed he is with the / Colour of autumnal days, / O red dragonfly."
The poet Lord Tennyson, described a dragonfly splitting its old skin and emerging shining metallic blue like "sapphire mail" in his 1842 poem "The Two Voices", with the lines "An inner impulse rent the veil / Of his old husk: from head to tail / Came out clear plates of sapphire mail."
The novelist H. E. Bates described the rapid, agile flight of dragonflies in his 1937 nonfiction book Down the River:
I saw, once, an endless procession, just over an area of water-lilies, of small sapphire dragonflies, a continuous play of blue gauze over the snowy flowers above the sun-glassy water. It was all confined, in true dragonfly fashion, to one small space. It was a continuous turning and returning, an endless darting, poising, striking and hovering, so swift that it was often lost in sunlight.
In technology
A dragonfly has been genetically modified with light-sensitive "steering neurons" in its nerve cord to create a cyborg-like "DragonflEye". The neurons contain genes like those in the eye to make them sensitive to light. Miniature sensors, a computer chip and a solar panel were fitted in a "backpack" over the insect's thorax in front of its wings. Light is sent down flexible light-pipes named optrodes[c] from the backpack into the nerve cord to give steering commands to the insect. The result is a "micro-aerial vehicle that's smaller, lighter and stealthier than anything else that's manmade".
[Credit: en.wikipedia.org/]
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SMART SUPPORT SOCKET
The Smart Support Socket is a step out of the comfort zone and introduces a new way of not only supporting the Smart Doll body - but also providing extensibility for accessories and robotics in the future.
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Silla que aúna estética y comodidad gracias a la curvatura de su asiento monocasco y tapicería con espuma de poliuretano inyectado con tapizado cosido artesanalmente.
La sencillez de lineas y el amplio abanico de medidas de este modelo son sus características principales. El armazón metálico se ofrece en acabados aluminio, blanco y negro, y la encimera es de cristal templado de 8 mm en todos los colores del muestrario y además una versión de cristal mate transparente.
Pensada para espacios estrechos, la mesa Concept Minor incorpora un sistema de extensión mediante el desplazamiento frontal de las patas, pasando de un ancho de 52 cm a un cómodo ancho de 80 cm en posición abierta. Incorpora un cómodo sistema de rodaje en las ruedas para facilitar la apertura. Se fabrica en armazón metálico aluminio, cromado, blanco y negro, y encimera en vidrio de templado de 8 mm.
La primera mesa del mercado que se adapta en medida de largo, ancho y alto a las necesidades de cada usuario. La encimera puede fabricarse en laminado rígido o cristal templado de 8mm, y ahora, además, puede incorporar ruedas en las patas!!!
Disciplines / Task Styles:
- F1A (Gliders) - seniors
- F1B (Model Aircraft with Extensible Motors Wakefield) - seniors
- F1C (Power Model Aircraft) - seniors
Place: Moncontour (France)
Dates: 03 Aug to 10 Aug 2013
Photo by Cenny Breeman
Disciplines / Task Styles:
- F1A (Gliders) - seniors
- F1B (Model Aircraft with Extensible Motors Wakefield) - seniors
- F1C (Power Model Aircraft) - seniors
Place: Moncontour (France)
Dates: 03 Aug to 10 Aug 2013
Photo by Cenny Breeman
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This photo was intended to show the size difference between the three plows in the Extendable family.
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Disciplines / Task Styles:
- F1A (Gliders) - seniors
- F1B (Model Aircraft with Extensible Motors Wakefield) - seniors
- F1C (Power Model Aircraft) - seniors
Place: Moncontour (France)
Dates: 03 Aug to 10 Aug 2013
Photo by Cenny Breeman
Pensada para espacios estrechos, la mesa Concept Minor incorpora un sistema de extensión mediante el desplazamiento frontal de las patas, pasando de un ancho de 52 cm a un cómodo ancho de 80 cm en posición abierta. Incorpora un cómodo sistema de rodaje en las ruedas para facilitar la apertura. Se fabrica en armazón metálico aluminio, cromado, blanco y negro, y encimera en vidrio de templado de 8 mm.
Disciplines / Task Styles:
- F1A (Gliders) - seniors
- F1B (Model Aircraft with Extensible Motors Wakefield) - seniors
- F1C (Power Model Aircraft) - seniors
Place: Moncontour (France)
Dates: 03 Aug to 10 Aug 2013
Photo by Cenny Breeman
Event classification: Open International - World Cup Event
Disciplines / Task Styles:
- F1A (Gliders)
- F1B (Model Aircraft with Extensible Motors Wakefield)
- F1C (Power Model Aircraft)
- F1Q (Electric Power Model Aircraft)
Photo by Cenny Breeman
Place: St Jean de Sauves (France)
Dates: 29 Jul to 30 Jul 2013
La primera mesa del mercado que se adapta en medida de largo, ancho y alto a las necesidades de cada usuario. La encimera puede fabricarse en laminado rígido o cristal templado de 8mm, y ahora, además, puede incorporar ruedas en las patas!!!
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A wild tangent inspired by Dominik Strzelec's Processing demo of catenary curves in Toxiclibs.
I was curious about the simulation aspect and how it might relate to parametric modeling, but then I added some basic color shading and promptly forgot about everything else. Sketches like these don't really have a defined place in my current practice and I usually only get to show them in lectures, so by now I have a growing elephant graveyard of code sketches like these.
I'm embarrassed to say this is the first time I've seriously used Toxiclibs for more than 20 minutes. It really is a thing of beauty and contains some very powerful tools once you figure out Karsten's code structure. Most coders tend towards idiosyncracy and Karsten is no exception, but his manifests itself in the form of well-thought out and extensible code structures while mine are far less elegant.
I plan to post a version of my sketch on OpenProcessing as a nod to Dominik for using his code. The physical simulation is still Toxiclibs, but I've moved all rendering, GUI and meshing to Modelbuilder for my own convenience's sake.