China
Africa
Explore chapters and articles related to this topic
Anthropometrics and Workspace Design
Published in Robert W. Proctor, Van Zandt Trisha, Human Factors in Simple and Complex Systems, 2018
Robert W. Proctor, Van Zandt Trisha
Baber (2006) defined tools as “objects external to the user that support engagement with objects in the world” (p. 8). We can divide hand tools into two categories: manual and power. The forces necessary to operate manual tools are provided entirely by human muscles, whereas those for operating power tools come in part from external sources. Regardless of what type of tool it is, the purpose of a tool is to facilitate the performance of tasks that would be difficult or impossible to perform without it, such as removing a screw, tightening a lug nut, or cutting a piece of sheet metal. Power hand tools have the additional benefit of replacing or augmenting a user's physical strength with a different primary energy source, thereby reducing the amount of physical energy expended by the user and increasing the amount of force that he or she can generate.
Tools
Published in Ron Heiskell, ® Changeover, 2020
Tools are occasionally required, but sometimes they can be modified to reduce effort. Take, for example, the NASCAR race gun (air-impact wrench) that is used to remove lug nuts. The gun is never shut off as the wheel changer moves from one lug nut to the next; the socket is jammed onto each lug nut while the gun is running at 18,000 rpm. This is possible because the inner sharp faces of the socket are ground off so there is only enough flat surface to remove the lug nut. A spring is also installed in the socket to push the lug nut out of the socket before the socket lands on the next lug nut. This is an excellent example of Lean thinking. By making these modifications to the air-impact wrenches, all wasted effort is eliminated.
Essences of Interaction
Published in Gary O. Langford, Engineering Systems Integration, 2016
The frame of objective causalities is applicable to building cars (when engineers formulate plans, follow procedures, and model expected results), to delivering cars with requisite physical characteristics, required functions (with acceptable performance(s) and acceptable loss(es) to achieve those performances); predicated on their design, architecture, development, and integration work to achieve the requisite desired behaviors that accompany the physical object and accommodate the other objects that are (or deemed to be) part of the race event. Beyond the objects of cars and people, the framework can be used to construct the objects that comprise the totality of the “race event.” The “race event” could include the “crash” event, or not, depending on the objective of constructing the “race event.” This grand ensemble would include objects of the race, formulated by planning and carrying out process(es) for procedures to manage the organizing of which cars compete in which race (assuming more than one race), where the cars will be positioned before and after the race, where the winner will be stationed or presented with the results of winning, and where the car will be serviced before leaving. Every aspect of the abstraction referred to as “the race” is definable with the framework of objective causalities. The bringing together of the “race event” constituent objects depends on definable interactions that are either observed or deemed reasonable given the before and after events. No doubt there will be emergent attributes that result from the “race event.” As we will find in Chapter 3, emergence is commonplace. Temporary emergence(s) arises during the event, for example, a mechanic using a wrench tightens a lug nut, scrapes the fender, and rips a shirt sleeve (the rate of ripping a shirt is an attribute of the interaction between the shirt and the means of ripping; whereas the rip in a shirt is an attribute of the shirt). Temporary emergence can be sustained as long as the appropriate EMMI is available and the context and circumstances support the emergent attribute(s). This reversible circumstance is metastable, with the mechanic recovering fully, the car repainted, and the rip in the shirt sleeve mended. Unless there are irreversible actions (such as could result from a devastating car crash), the only interactions that occur are included in the “race event.” The notion of time that in some manner links events can be investigated by dividing up “race event” into its causal trails, its proximate conditions, and its local circumstances.
Self-expanded piles: A new approach to unconventional piles development
Published in Marine Georesources & Geotechnology, 2021
Ebrahim Shojaei, Abolfazl Eslami, Navid Ganjian
The other parts of the pile consist of a long lug nut (Figure 1(d)) and a central steel bolt with a diameter of 30 mm similar to the arbor bolt (Figure 1(e)) placed in the middle of the main shaft. The thread length of the bolt is about 150 mm. By applying the torque power on the upper end of the bolt by a handle (Figure 1(c)), the central bolt closed like a long screw bolt inside its nut, and the length of the central shaft in the upper part is reduced. The reduction in the length of the central bolt causes the upper part of the outer wall (the upper part of the highest joint) to penetrate into the soil and in turn expansion of blades, and simultaneous formation of a steel cube in soil. Design of whole parts of the joints was such that the blade extension occurred uniformly to shape a cube, in order to increase the cross-section area (Figure 1(f)).