Pressure mat

Smith DM, Deshpande R, Brinker CJ (1992) Preparation of low-density aerogels at ambient pressure. Mat Res Soc Symp Proc Vol. 271 567-572... 

Matched die molding preform and mat Reinforcement and resin are combined under heat and pressure. Mat reinforcements are used for relatively flat shapes. Complex parts require a preform. 

Some safeguarding devices are used to detect the presence of people and to trip the machines they safeguard. The main two to be described here are photoelectric safety systems and laser scanners, which are both types of active optoelectronic electrosensitive protective systems. Pressure sensitive devices such as pressure mats and trip bars are other types of trip device. 

Fig. 1 shows a 32 X 32 sensors pressure mat (FSA pressure mapping system, Vista Medical Co., Winnipeg, Canada) to receive the pressure distribution data, a tilt adjustable electric wheelchair (Nita International Enterprise Co., Ltd., Taichung County, Taiwan) as inclination controller and a notebook (model X31, BenQ International Co., Ltd., Taipei, Taiwan) and LabVIEW (Version 8.6, National Instruments Co., Austin, Texas) to collect data. 

Subjects experienced four different inclinations) 100°, 110°, 120° and 130 °) sets on separate four days. Each set of 80 minutes included 10 minutes for adaptation, 60 minutes for data acquisition and 10 minutes for pre-end. The purpose of setting the adaptation period is to remove the factor subject just begin to sit on the wheelchair and move to adapt the chair that may affect our analysis. The purpose of setting the 10 minutes before the end of the experiment is to avoid subjects may expect the experiment will over and float of psychological situation. Four Experiment for the same subject were implemented at the same hour in four days. 32 x 32 sensors pressure mat data then separate it into two parts back and hip. Calculate the values of the compressed sensor to determine the posture changing range and pattern of back and hip. 

With a pressure mat and analysis program, we found that different subject has significantly difference to the other subject in the same inclination. The frequency of posture change are different in different subjects, too. 

Kinetic analysis is an analysis of the forces acting on a system motion and has been described by maity authors [1-8] using several devices such as force platforms, treadmill associated with force platforms, pressure mats. 

Recently, a human gait analysis tools have introduced GAITRite system, a pressure mat, which measure spatio-temporal parameter, peak vertical pressure and velocity of walk. Combined with specialized qnadraped-adapted software, this system can calculate these parameters for each limb at the same time and in the same conditions at one walk. 

The fore/hind Umb ratio of maximal pressure was 1.60 (SD) for large dogs. Our values in large dogs were higher than the recent reports in healthy large-breed dogs were 1.38 [1] or 1.42 [15] or 1.46 for system platform and 1.38 for system pressure mat [6]. But this value in our study was similar to result 1.61 of Bockstahler (2007) [8]. 

Dry-Process Hardboard. Dry-process hardboard is produced by a dry—dry system where dry fiber is formed iato mats, which are thea pressed ia a dry coaditioa. A flow diagram of this process is showa ia Figure 6. Ia this process, wood chips, sawdust, or other residues are refiaed to fiber ia pressurized refiners. Wax and PF resia may be added ia the refiner or ioimediately outside of the refiner, ia the fiber-ejectioa tube or "blowliae." It is also aoted that a small amouat of dry-process hardboard is made with UF resia biaders. UF resias, because of their inherent faster curing at lower temperatures, can be added only at the blowline or ia a bleader located after the dryer. 

The mats are moved along the line to the press loader. When the loader is filled and the press opens to remove the load of freshly pressed boards, the loader pushes the new boards into the unloader and deposits the load of mats on the press platens. The press closes as quickly as possible to the desired panel thickness. More pressure, as much as 4.8—6.9 MPa (700—1000 psi) is required to press high density dry-process hardboard, because the dry fiber exhibits much more resistance to compression and densification than wet fiber. Press temperatures are also higher, in the range of 220—246°C. No screens are used in the dry-process, but the moisture in the mats requires a breathe cycle during pressing to avoid blowing the boards apart at the end of the cycle. Because no screens are used, the products are called smooth-two-sides (S-2-S), in contrast to the wet-process boards, which have a screen pattern embossed into the back side and are known as smooth-one-side (S-l-S). 

Otner Collectors Tarry particulates and other difficult-to-handle hquids have been collected on a dry, expendable phenol formaldehyde-bonded glass-fiber mat (Goldfield, J. Air Pollut. Control A.SSOC., 20, 466 (1970)] in roll form which is advanced intermittently into a filter frame. Superficial gas velocities are 2.5 to 3.5 m/s (8.2 to 11.5 ft/s), and pressure drop is typically 41 to 46 cm (16 to 18 in) of water. CoUection efficiencies of 99 percent have been obtained on submicrometer particles. Brady [Chem. Eng. Prog., 73(8), 45 (1977)] has discussed a cleanable modification of this approach in which the gas is passed through a reticulated foam filter that is slowly rotated and solvent-cleaned. 

For mass production purposes matched metal moulding techniques are employed. Here the preform or mat is placed in a heated mould and the resin poured on. The press is closed and light pressure ( 501bf/in ) applied. Curing schedules are usually about three minutes at 120°C. It is possible to produce laminates using less resin with pressure moulding than with hand lay-up techniques and this results in better mechanical properties. 

Particulate Reinforced Metals Via Pressure Infiltration" J. Mat. Sci., July, 1990. 

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