Dynamite Alfred Nobel Essay Example

Dynamite Alfred Nobel Essay Example Dynamite Alfred Nobel Essay Dynamite Alfred Nobel Essay For the implementation of the tests for explosive-based cable bolts, three different explosives gunpowder, emulsion dynamite and gelatinite dynamite were used (Thompson, 285-291). The amount of explosive to be placed into the cap is very important. If the amount of explosive becomes relatively high, a greater than required pressure will be applied onto the borehole wall. As a result of this pressure, some cracks may occur in the rockmass. In contrast to this, if the explosive is less than needed, the cap will not expand adequately, and the anchorage capacity will be decreased. According to calculations carried out for the gelatinite dynamite, the required amount of the explosive was found to be ~780 g. However, this amount is only a reference quantity for a first approach. The real quantity, found using the trial and error method in the tests, amounts to 75 g/cap. Similarly, explosions are conducted on large scales in the destruction of buildings, in a way that the surrounding areas have minimal effects of the dynamite blasts and the tasks of the engineers are accomplished very efficiently and effectively (Perrings, 129-135). â€Å"In 1867 dynamite was invented, and in 1869 the mechanical drill run by compressed air was invented. These two inventions created a technological revolution in the mining industry. Dynamite was safer and easier to control than black powder. A steam engine-driven air compressor for the mechanical drill was generally installed outside the mine, and air lines were extended to the drills under ground. Most mines were worked on a small scale, with only a few miners and support personnel. † (Technology of Colonial and Victorian Iron Mining) The anchorage of the first 8 concepts was provided by a friction force developed through expansion of the cap in the borehole wall (Thompson, 285-291). However, for the oblique concept, a rotational moment has been additionally created by the pulling of the cable attached to the cap. The cap designed for this concept is shown in Figs. 1 and 2. In this concept, the upper part of the cap has been designed to be inclined. There were also 2-mm deep scratches on the cap as for the other concepts. These scratches facilitate the expansion of the cap. In this system, the barrel and wedge anchor for holding the cable causes the rotational moment on the cap. This rotational moment gives rise to additional friction between the cap and the borehole wall. These oblique caps are illustrated in Fig. 3. The invention of dynamite in the middle of 19th century was surely a breakthrough in some of the industrial processes. It was through this dynamite that, Alfred Nobel made further discoveries and went on to make a number of industries. The use of dynamite still dominates in the mining and construction industries and is considered to be one of the most significant discoveries of its time. A. G. Thompson: Tensioning reinforcing cables. Rock support in mining and underground construction, Rotterdam, Balkema, 1992, 285-291. Alfred Nobel His Life and Work http://nobelprize. org/alfred_nobel/biographical/articles/life-work/index. html Accessed, March 18, 2007

Describing Non-Disabled Children as Typical

Describing Non-Disabled Children as Typical Typical, or Typically Developing is the most appropriate way to describe children who are not receiving special education services. Normal is frankly offensive since it implies that a special education child is abnormal.  It also implies that there is a single norm for children.  Instead, it is preferred to refer to children without disabilities as typical because they have the behavior, intellectual ability and functional skills we would typically see in children of their age. How Mental Disability Used to be Defined At one time, the only measure of whether a child was disabled was how he or she performed on a measure of Intelligence, known as an IQ Test. Describing the intellectual disability of a child was defined by the number of IQ points below the mean of 100 a child would fall.  20 points was mildly retarded, 40 Points was severely retarded.  Now, a child is to be considered disabled if her or she fails to respond to intervention, or RTI.  Instead of performance on an intelligence test, the childs disability is defined by his or her difficulty with grade appropriate academic material. How to Define Typical A Typical child would perform within a standard deviation of the mean of all childrens performance.  In other words, the distance on either side of the mean that represents the largest part of the curve of the population. We also can benchmark the social behavior of typical children as well.  The ability to talk in complete sentences, the ability to initiation and maintain conversational exchange are behaviors, behaviors for which speech language pathologists have created norms.  Oppositional defiant behavior can also be compared to the behavior expected of a child of the same age without disruptive or aggressive behavior. Finally, there are functional skills which children typically acquire at certain ages, such as dressing themselves, feeding themselves and typing their own shoes.  These can also be bench marked for typical children.  At what age, does a child child tie his or her shoes?  At what age does a child typically cut his or her own food, using both hemispheres. Typical is especially appropriate when comparing a typically developing child with a child on the autism spectrum.  Children with autism spectrum disorders have a great many language, social, physical and cognitive deficits.  In many cases they are related to developmental delays that children with autism experience.  It is often in contrast to typically developing children that we can best describe the needs of special education children. These students are sometimes referred to as Regular Education Students or General Education Students. Example of How to Use the Word   Ms. Johnson looks for as many opportunities as possible for her students with severe cognitive challenges to engage their typical peers.  Typical children encouraged the children with disabilities while at the same time modeling age appropriate behavior.