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Drilling techniques and drilling machines
Published in Roger Timings, Engineering Fundamentals, 2007
Most drilling machines are provided with adjustable stops attached to the quill as shown in Fig. 9.7(a). You can see that the depth stop is engraved with a rule type scale graduated in millimetre or in inch units on its front face. This scale is used as shown in Fig. 9.7(b). Touch the drill onto the work and note the reading on the scale. Then use the scale to set the stop nut and lock nut. Figure 9.7(c) shows how these nuts stop the in-feed of the drill when the set depth has been reached. For precision depth setting, slip gauges can be used as shown in Fig. 9.7(d).
Source Sampling
Published in Howard E. Hesketh, Air And Waste Management, 2019
Rinse the container with two or three 25 ml portions of acetone, cap the container and shake, then transfer into the graduated cylinder to rinse it, and then put the rinse through the funnel into a beaker; thus, the container, the graduated cylinder and the funnel have been rinsed.
Metals, Toxic Organics, and Color Removal at A Manufacturing Facility
Published in Gregory D. Boardman, Hazardous and Industrial Wastes, 2022
ERM tested ozone as an oxidizing agent. ERM used an OREC Model V10-AR/O ozonator with air as the oxygen source. ERM placed one liter of ultrafilter permeate in a 2-liter graduated cylinder. A 2-inch porous stone diffuser attached to an ozone supply line was placed in the graduated cylinder.
Alkali-activated mortars: porosity and capillary absorption
Published in European Journal of Environmental and Civil Engineering, 2023
Moussa Ka, David Hoffmann, Laurent Molez, Christophe Lanos
Capillary absorption of the mortars prims specimens (40 mm × 40 mm × 150 mm) is carried out on a test device made in the laboratory (see Figure 3). Samples are first rectified. They are sawed 0.8 cm on one of their ends to obtain a characteristic absorption surface representative of the heart of the sample. Mortar specimen is dried at 60 °C until this weight became constant (the mass is considered constant when two successive weightings carried out at 24 h apart do not differ by more than 0.05% between them). All the lateral and upper surface of the sample is sealed using adhesive aluminum paper to avoid any phenomenon of water evaporation. One of the lateral surface is coated with a transparent waterproof film to visually record the height of the water rising. A graduated ruler is placed on this face to evaluate the absorption height. The dried sample mass is measured after preparation (Wd). The sample is then suspended under an electronic scale. Sample base is placed in a container filled with water using a water pump to maintain by mean of overflow a submerged height of 10 mm. The sample mass evolution is recorded from the start of immersion until 24 h. The sample mass (Ww) is conventionally measured after 15, 30 min and then 1, 2, 4, 8 and 24 h of immersion. At each term, the height (Hw) of the capillary front is quoted using the graduated ruler.
Field performance monitoring of pervious concrete pavements
Published in Road Materials and Pavement Design, 2023
Avishreshth Singh, Prasanna Venkatesh Sampath, Krishna Prapoorna Biligiri
In order to perform this test, an infiltration ring of internal diameter of 270 mm was embedded into the PCP surface layer during construction, as shown in Figure 2a. The bottom of the rings was sealed with a geomembrane to restrict the flow of water into the underlying sub-base layer. Additionally, slotted pipes were extended from the base of embedded rings to the side of the PCP for draining the water during testing. More details about the procedure involved in installing the rings within the PCP surface wearing course layer may be found elsewhere (Vaddy et al., 2020). Another ring, identical to the embedded ring in size, was placed over the pavement surface, and their interface was sealed with glass putty (Figure 2b). A graduated steel ruler was fixed over the ring. Initially, the PCP slabs were pre-wetted by pouring water and keeping the outlet of the pipes open. Once the water dissipated from the surface, the outlet was closed and water was ponded to an initial head of 22 cm. After dissipation of the air bubbles, the outlet of the pipe was opened and the time taken by water to fall from the initial head to the final head of 4 cm was noted. The infiltration rate (K) was computed in cm/s.
Teaching and learning angles in elementary school: physical versus paper-and-pencil sequences
Published in International Journal of Mathematical Education in Science and Technology, 2022
Valérie Munier, Claude Devichi
We hypothesized that the different techniques would appear spontaneously. Indeed, in accordance with Mitchelmore and White’s proposals (2000), it is important that pupils use different angle comparison and reproduction techniques to tackle as many aspects of the angle as possible. The purpose of this practice is to help students to identify similarities between various physical situations expressed by the same geometric concept (the angle), thus enabling them to classify angles (inclination, sector, etc.). Not surprisingly, children thought of different tools of comparison. The graduated ruler was initially used by the majority of students to measure the length of two sides. Nevertheless, some students reacted against measuring the ropes, saying, ‘That's useless because it goes on to infinity [gesturing in the direction of the rope].’ Some pupils attempted to measure the ‘space’ between the two sides, but not everyone measured this ‘space’ at the same distance from the screen (see Figure 4). They focused on measures of length with which they were familiar. Others believed that it only made sense to measure this space at the same distance from the screen. This idea suggests that these pupils implicitly considered the concept of angles as a space between two directions, independently of the lengths of the sides.