A flake is a piece of raw material that has been removed by a variety of removal techniques. Diagnostically there are five flake types I describe more in depth in question four. In order to produce the desired flake the flintknapper can utilize either percussion or pressure flakings in order to remove the flake from the raw material. At the removal of a flake a wide range of characteristics can be annotated. Location of the platform aids in identifying the initial impact area and orientation of the flake. Primary flakes are removed from the core first therefore on the dorsal side they will posses a portion of the cortex, or exterior of the raw material used. Any additional flakes will have characteristics of the primary flake on its now dorsal …show more content…
Emanating from the bulb of force will be ripple like compression rings that will be a visual representation of the force that traversed the material while on its way to remove the flake. Flake termination is another characteristic and is observed by the edge breaks. The most useful and planned one is the feather termination, this termination produces thin and sharp edges ready for use as blades or knives. The footprint on the core is positive and more flakes can be successfully removed in succession. While the most ideal termination there are others that will happen while producing flakes off of cores. Hinge fractures have the ability to be repurposed into a usable tool however they are not a planned fracture. If there was not enough force applied in the hit the force will take a shortcut to the edge leaving a rounded break that possesses a sharp point on the outer edge of the core. The fracture that will be caused due to an incorrect angle or insufficient force are step breaks and in resembling their name they look like a stair step. The force rebounds and exits the core at a 90 degree angle, causing a potentially fatal break to the core causing it to be tossed …show more content…
They take a great deal of practice and work to make however just a few steps to produce one. Basic steps include selecting a suitable core, percussion flaking, pressure flaking and notching. Selecting the a core entails having . Percussion flaking procedes finding the core. Location of a platform with a ridge angle less than 90 degrees and strike with one solid hit in order to remove a flake. After removing a handful of flakes, selection of the perfect flake corresponds with skill. As I am not a skilled flintknapper yet an ideal a arrowhead blank would not be paper thin around the perimeter but without a gross amount of thickness. Avoiding a curved flake should also be avoided since during the reduction process to correct the curve too much of the material may be lost, however it is not impossible to make a successful arrowhead. Pressure flaking will be able to remove mass on both sides while shaping and removing any excess cortex that may be present or any other dorsal and ventral marks by its completion. Setting up to begin pressure flaking is as follows, holding the flake against a tanned piece of leather on the solid part of the palm with the fingers grasping the center of the flake in one hand and resting on your lap. The other hand holding the pressure flaker either man-made or a piece of antler press the tip into the flake in order to remove the desired flake. After each flake is removed using a sandstone
The etiology of calcaneal fracture is usually high energy trauma such as fall from a height or motor vehicle crash 1,2.
10. Point the flask away from everyone and open the two-way valve in order to release pressure from the flask. Remove the stopper assembly, then fill up the flask with water. Discard of the solution in the sink.
Die-forming of sheet metal has been around for thousands of years. Originally the metal was manipulated by hand and hammered into the depression, by utilizing crude grooves carved into wood or stone. This technique was used to make spouts, handles, and other forms. Since then, however; they have undergone a remarkable technological evolution. Mate-female conforming dies to create hollow forms by using hydraulic pressure or drop hammer pressure, changed die-forming forever (Paisin, 2013).
It is the most important and the most complex stage of fatigue fracture. There is an irreversible change in the metal caused by repetitive shear stresses which is the most significant factor in the initiation process. The initiation site of any fatigue fracture is very small. It is never more than two to five grains around the origin. At the location of stress concentration points, the number would depend on geometry, environment, stress, and strength conditions. If this stage can be seized than fracture phenomenon would not take place.
In the prepping process you will begin to draw out vessel shapes on paper (up to ten). You will then choose a shape and draw the chosen one on cardboard. Then you will simply cut the shape out.
Fractures occur when a force is placed on a bone and the force is greater than the bone can withstand. A greenstick fracture is most often caused by:
This tool has a thin metal sheet or ribbon attached to the handle. The ribbon carves into the material.
The most dangerous fractures are those of the hip especially for elderly people. Studies have found that only about a third of people who get a hip fracture return to normal even after treatment. In fact, about 20 percent of the elderly people who get this fracture die within a year.
Nevertheless, it may also lead to mandibular fracture. Bone strength reflects the integration of 2 main features: bone density and bone quality.”(3). probably the only clinically applicable index of bone quality at present is a patient’s history of a fragility fracture. In the absence of methods of measuring bone quality, the diagnosis of osteoporosis tends to be made on the basis of low bone density. (Note: The World Health Organization (WHO) (4) defines fragility fracture as “a fracture caused by injury that would be insufficient to fracture normal bone: the result of reduced compressive and/or torsional strength of bone.” Clinically, a fragility fracture may be defined as one that occurs as a result of minimal trauma, such as a fall from a standing height or less, or no identifiable trauma
These are all strong materials. Nevertheless, you may find yourself in need of emergency denture repair for several different reasons. Some of the most common reasons why dentures fracture include:
A nasal fracture is a break or crack in the bones or cartilage of the nose. Minor breaks do not require treatment. These breaks usually heal on their own in about a month. Serious breaks may require surgery.
The PetroThin allows for a quick, accurate, repeatable way of thinning within +5 microns, before a final chemical etch.
This solution was then added to a 250cm3 volumetric flask using a funnel. The beaker and funnel were swilled thoroughly using a small amount of water these washing were then added to the volumetric flask. Water was then added to the volumetric flask until it was about 1cm below the graduation mark. The water was then added slowly from a clean pipette so that at eye level the bottom of the meniscus was just touching the graduation mark. The volumetric flask was then stoppered and then inverted.
To make small holes, movement involves are flexion and extension of elbow and forearm joint. Next, PIP extension.
There are four types of method; potter’s wheel, pinching by hand, coiling, and slab making. Potter’s wheel is best for bowls, plates or even vases. Pinching by hand is usually for small object. Coiling is best for hollow or non-hollow symmetrical pottery. This method allows you to make amazing texture by coiling two patterns into whole clay. Slab making is best for flat sided pottery like decorative box.