the design of everyday things by don norman pdf download

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Ngày tải lên: 10/05/2015, 14:31

... Summary of Tense Conventions At its heart, the invention of a reference work is really the invention of a set of conventions followed by their application with relentless consistency. This is the ... know they have it. Get tested: The odds a female 15–44 has been tested for HIV and other STDs in the past year are 1 in 10.5. The odds a male 15–44 has been tested for HIV and other STDs in the ... randomly and collect their numbers humbly and confess how wrong they may be honestly and report what they see whether it is what they wished for or not and share what they find with all of us so we may...

Ngày tải lên: 03/04/2014, 17:15

... as the beasts of the field, the birds of the air and the fish of the sea are bountifully supplied. For any man, no matter what his station in life, to take the stand that it is the destiny of ... keeps the airplane soaring. Without resistance, it could not fly. Neither could the birds; or the fish swim; or you walk. As the power of the engine increases, the greater the momentum of the ... following pages are the result of a series of notes collected and set down in the form of a story and a system of practice, which accounts for the style of arrangement. The sequential order...

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Ngày tải lên: 26/06/2015, 18:05

... 119 pcf Example 4. Design the steel lying in the East-West direction of the mat shown below with external dimensions of 42 feet by 74 feet. The columns are all 15 by 15”, the LF = 1.6, f c ’ ... 0.00018y. Values are solved by plugging in the x and y values, which these values are found by using the x-y coordinate system off the mat foundation. Determine the average soil reaction. ... years, the dredged material from nearby waterways and excavated soil from a neighboring project sat on the mill site. The material acted as a surcharge which compacted the soil to the point of...

Ngày tải lên: 16/10/2012, 10:43

Ngày tải lên: 14/12/2013, 00:41

... accuracy of the workpiece mainly depend on the axial rigidity of the spindle headstock and of the rotary table. Therefore, the rigidity of the thrust bear- ings is especially important. To increase the ... the expansion of the rotating parts due to the effects of heat and centrifugal force do not cause jamming of the outer rings in the housing. Lubrication, sealing The bearings are lubricated by ... on the roll- ing bearing aspects of the applications. The operation of the machine allows conclusions to be drawn about the operating conditions which dictate the bearing type and design, the...

Ngày tải lên: 25/12/2013, 05:17

... lubrication. The labyrinth seal at the work end consists of ready-to- mount, non-rubbing sealing elements. The inner laby- rinth ring retains the lubricating oil, the outer laby- rinth ring prevents the ... kN; the bearings are vertically arranged. Bearing selection The axial load of 130 kN is made up of the weight of the rotor and the two variable top and bottom fan im- pellers as well as the thrust ... clearance Due to the tight fits, the inner ring of the bearing is expanded and the outer ring with the roller-and-cage assembly is contracted. Thus the radial clearance of the bearing is reduced...

Ngày tải lên: 25/12/2013, 05:17

... to the shoulder of the person who has fired it—corresponding to the momentum of the bul- let. Why, then, does the “kick” not knock a per- son’s shoulder off the way a bullet would? Because the ... Conservation Laws Then, as the ball hits the ground, the energy is dispersed. Most of it goes into the ground, and depending on the rigidity of the ball and the ground, this energy may cause the ball ... make the situation more plausible, the “Man of Steel” should have been shown catching the person, then slowly fol- lowing through on the trajectory of the fall toward earth. THE CRACK OF THE BAT: INCREASING...

Ngày tải lên: 19/01/2014, 13:04

... Typically, the designer designs a product with minimal knowledge about the capabilities and limitations of the manufacturing technology. The designer then tries to find out if the design can be ... ways of simplifying CSG models for their potential use in feature recognition. ã Restrict the domain of the model by restricting the range of primitives and/or of the orientations that they may ... beforehand, then the best configuration of the spindles for the parallel machine tool can be deduced. The best configuration of the spindles could be based on the types and number of features present on the...

Ngày tải lên: 19/01/2014, 18:20

... limited. The case of shut down of an existing plant results when the variable W it takes a value of zero after a given time period t. The economics of shut down can be modeled by the inclusion of the ... for the production of each chemical. We might then contemplate the in-house production of some of the required ingredients, forcing us to consider another tier of ingredients and by- products. The ... assumed that the production rate (r ijt ) of the main product j of each such scheme is proportional to the capacity of the plant. where M i denotes the index set of main products of the alternative...

Ngày tải lên: 19/01/2014, 18:20

... fills the interspaces of the universe. This Sub- stance is the Life of All, and is seeking to express more life in all. It is the Prin- ciple of Life of the universe, and the Principle of Health ... life is the Principle of Life of the universe. This Substance has created from itself all the forms of or- ganic life by thinking them, or by thinking the motions and functions which produce them. Original ... control his attention by the use of his will. He can decide what things he will think about. www.scienceofbeingwell.net The Science of Being Well 24 visible by the transformation of the physical body...

Ngày tải lên: 21/01/2014, 21:20