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Flume study on driftwood jam and flood damage to house around a bridge
Published in Wim Uijttewaal, Mário J. Franca, Daniel Valero, Victor Chavarrias, Clàudia Ylla Arbós, Ralph Schielen, Alessandra Crosato, River Flow 2020, 2020
T. Okamoto, T. Someya, M. Sanjou
As mentioned above, many researchers have investigated driftwood jam formation. However, there are few experimental study, published on blockage ratio of driftwood jam at bridges and floodplain flow. So, in this study, flume experiments were conducted. First, wooden dowels were used to model driftwood. Backwater rise due to woody debris jam was measured. The results were compared with the porous board tests (Okamoto et al. (2020)) and we examined the blockage ratio of driftwood jam. Next, we tracked behavior of incoming log on floodplain to evaluate the convection velocity. Then, the force exerted on the model house on floodplain was measured using a force gauge. The measured data was compared with the wooden house demolitions criteria.
Measurements of the Forces needed to Move Patients in Mobile Lifting Hoists and Hospital Beds
Published in Paul T. McCabe, Contemporary Ergonomics 2004, 2018
with a Mecmesin advanced force gauge (model AFG 1000N). In some cases the force measurements were instantaneously recorded and graphed (the data was down-loaded to a lap-top computer and stored with Dataplot software). The slope of the ramp at the scene of the incident was measured with an inclinometer. The instrument used was a Macklanburg Duncan "Smarttool" electronic spirit level (an inclinometer that is capable of measuring gradients to the nearest 0.1 degrees).
Mechanical Displacement Pumps
Published in Igor Bello, Vacuum and Ultravacuum, 2017
The experimental determination of pumping speeds and pumping characteristics is based on maintaining constant pressure during measurements. The system for these measurements is illustrated in Figure 11.17. First of all, the measured oil rotary pump (11) is installed on a standardized chamber (10) of unique shape and size as described above. The size of the chamber is adapted to the size of the pump. The positions of a leak pipe (7) and direct pressure gauge (8) (force gauge) are defined. The leaking gas can be supplied from two sources, that is, from the surrounding air atmosphere through shut-off valves (5 and 6) and leak valve (9). This pathway is used for setting the measurement conditions by a leak valve (9). After setting the condition, the gas source is switched to the second gas source by closing the valve (5) and opening the valve (4). The second gas source is confined between the cylinder (2) and oil. The cylinder (2) is thus pumped down via a pipe (3). As a result of this pumping action, the oil level in the container rises. The level position indicates the volume of gases removed from the cylinder (2) and leaked into the pumped chamber (10). The elevated level of oil is caused by the pressure reduction. However, the alternation of the oil level by 0.10 m means pressure change by (0.10 m/10.64 m) × 100 = 0.94% for the oil with a mass density of 0.95 g/cm3 at normal temperature. The oil level can thus climb up to the height of 10.64 m to balance the atmospheric pressure. When the oil level rises by 0.10 m only, the pressure change under the cylinder (2) can be considered as very small. Thus, the gas leak preset by the leak valve (9) and pressure in the chamber (10) are taken as constant with the indicated accuracy. The constant pressure also shows the vacuum gauge (8) during the elevation of the oil level. Increasing the oil level can be stopped by closing the shut off valve (4). Zero position of the oil level can be restored by closing the valve (6) and opening the shut-off valves (5 and 4) that equals the pressure with the surrounding atmospheric air.
AISI 2205 DSS for body-in-white automotive structure: effect of welding current and time on the performance of spot welded joint
Published in Welding International, 2022
Gautam Chudasama, Shubham Kashyap, Jay Patel, Vivek Kalyankar, Jayant Shewale
DSS of grade AISI 2205, having 1.2 mm thickness, is selected as a base metal (BM) and the chemical composition of the same is shown in Table 1. The AWS D8.9M [32] standard is strictly adopted to prepare and investigate the performance of prepared spot-welded samples. Experiments have been performed by industrial RSW gun with an advanced medium frequency direct current (MFDC) controller and feedback system (Make: Nash Robotics Pvt. Ltd., India) as is shown in Figure 1. Cu–Cr–Zr water-cooled conical electrodes with 6 mm tip diameter are used to obtain necessary spot weld joints. Pneumatic system is used to provide necessary electrode force. Force gauge is used to measure the electrode force and according to requirement of electrode force, required air pressure is set in the air-compressor based on trial and error.
Mode conversion from LP11 to LP02 based on in-line mode orientation control and antisymmetric refractive-index perturbation in a few-mode fibre
Published in Journal of Modern Optics, 2021
The experimental setup for evaluating the mode conversion process is shown in Figure 4. The initial LP11 mode wave was launched into the SI-FMF using a mode multiplexer (Kylia, M3) and a superluminescent diode (Amonics, ASLD162-100) with emission wavelengths around 1607 nm. The in-line polarization controller (I-PC) comprised the SI-FMF wound in three spool-like paddles with a diameter of 56 mm. Furthermore, we used a coil spring with a wire diameter of 0.4 mm to induce periodic perturbations in the SI-FMF. To maintain the shape of the coil spring and avoid disturbing the stretch performance during the loading operation, a light ceramic rod was inserted into the coil spring. The grating length, i.e. the interaction length, was determined by the length of the inner ceramic rod. The external force loaded on the SI-FMF was monitored using a digital force gauge. We observed the FFPs out of the SI-FMF via an infrared camera (Hamamatsu Photonics, C2741-03) equipped with FFP optics. The optical power transmitted through the fibres was measured using an optical power metre with an integrating sphere (Thorlabs, PM100D + S148C). The transmission spectra of the fibres were measured by an optical spectrum analyzer (Anritsu, MS9710B).
Current-pressure-position triple-loop feedback control of electro-hydrostatic actuators for humanoid robots
Published in Advanced Robotics, 2018
Tianyi Ko, Hiroshi Kaminaga, Yoshihiko Nakamura
To see the force measurement performance of the pressure sensor, strain gauge, and the complementary filtered value, we conducted a measurement experiment with the setup shown in Figure 3. The output side of the connecting rod was attached on a fixed force gauge. The actuator was under the force control, pushing and pulling the force gauge. The value acquired from the external force gauge is treated as the ground truth. To see the effect of thermal drift, we heated up the system by an external heat gun. The result is shown in Figure 4. The dot line represents the temperature of the system, acquired from a temperature sensor attached on the cylinder. The thick line is the grand truth. The less noisy but drifted line represents the force measured from the strain gauge. While it has the best accuracy at the beginning, a clear drift can be seen when the temperature rises. The RMS force measurement error is around 15.1 N. The not drifted but noisy line represents the force estimated from the pressure sensor. While there is no clear drift, it has a constant offset error. The RMS error is around 6.58 N. With the complementary filter, which is represented by the last line, the error is smaller to be 4.18 N, which is 0.28% of the maximum force.