Gouge marks

In wet ball milling the grinding rate increases with sohds content up to 70 wt % (35 vol%), as Fig. 20-33 shows, due to pulp rheology. Examination of gouge marks indicated that most breakage was by impact of balls on particles rather than by abrasion. 

The next condition and physical evidence we ll mention is rare, but we need to cover it in ease you should ever see it. You might see scratch and gouge marks all around the cireumferenee of strict tolerance rotary element ODs, and stationary element bores alike. This condition and marks is evidence of a Lack of Control . It could be from any of the... 

Nicks, scratches, or gouge marks on a pulley can cut into a belt. Dirt abrades the belting material and wear grooves cause a belt to bottom-out in the groove, resulting in slippage and ultimate damage to the belt. 

Examination using a scanning electron microscope (SEM) of the surface of abraded polyurethane shows cutting and gouging marks on the surface. The surface can deteriorate further, and fatigue cracks can start to appear. If the conditions are extreme, the surface can soften drastically and molten/ decomposed polyurethane can be seen under the SEM. 

Figure 14. A Man Hoist pad, showing gouging, pits and ferrous inclusions. Some gouge marks are for the full length of the braking surface, this would indicate that the ferrous inclusion had welded to the disc.

Gouge Marks Marks made in the earth by a vehicle where it has left the pavement. 

Often contain defects (hydrogen cracks, slag inclusions, stop-start marks). Help initiate fatigue cracks. Critical welds must be tested non-destructively and defects must be gouged out. 

Along with the sounds, evidence and signs of cavitation, there is a broad range of other information and signals available to the maintenance mechanic. Almost all mechanics have seen the gouge and scratch marks, and signs of heat on the pump when disassembled in the shop. Sadly, most mechanics are never trained to interpret these marks. 

You might sec gouge or wear marks all around the circumferences of close tolerances on the rotary elements, and a corresponding wear spot at approximately 60° from the cutwater on the stationary elements. 

If you see the same evidence, gouge and wear marks around the circumference of close tolerance rotary elements, and spots or arcs on the close tolerance stationary elements at about 180° from the cutwater, or straight down ... 

Next we ll discuss evidence marks and prints that are different, but to the untrained eye, they may appear the same. You may see a spot or arc of wear and gouging on the rotary elements, and a eireumferential wear circle on the bore of the close tolerance stationary elements. This is a maintenanee-indueed problem, d his is the sign of a physically bent shaft, or a shaft that is not round, or a dynamic imbalance in the shaff-sleeve-impeller assembly. The solution is to put the shaft on a lathe or dynamic balancer, verify its condition, and correct before the next installation. 

Rylands A. (1985). Tree-gouging and scent marking by marmosets. Anim Behav 33, 1365-1367. 

Because of the nature of the thin copper cladding, be sure that the router does not gouge the material. The /s" router bit ( 60719 from Micro Mark) I have indicated seems to work best, although other kinds will work. Be sure to supply this router bit to anyone who does the job for you unless they are confident that the router bit they will use won t make the copper edges too ragged. 

In captive callitrichids, scent marking behavior is also concentrated in specific locations. Common marmosets show a high amount of tree gouging under captive conditions, even though no sap can be obtained this way. 

Basic four of each vehicle (one picture from each side). Instruct drivers that vehicles can be examined further later for detailed damage, just fill the frame with the vehicle, snap, and move onto the next side, vehicles are not perishable. Perishable items are pavement condition and gouging, skid marks, offroad gouges, light conditions, parked vehicles, etc. 

Gouges, scratches, dent, paint smears, and rubber skid marks, etc. on surfaces... 

Permanent attachments such as footrings, headrings, neckrings or marking plates should be inspected to make sure they are in place and firmly attached. The area of attachment to the cylinder should be checked for possible entry of moisture to the cylinder surfaces that cannot be seen. In the case of adhesive attachments, any evidence of a break in the seal is cause for removal of the attachment. The use of a dull probing tool is recommended. Attachments made of plastic also must be checked carefully for gouges or splits, which would require their removal. When the cylinder bears a removable attachment such as a removable boot (footring), the attachment must be removed for visual inspection. 

Visual examination will also disclose the extent of consumer abuse. Gouges and deep marks in the plastic show signs of possible excessive use of the part. A foreign substance, such as a liquid, on the part should be investigated for possibly chemical attack on the plastic. 

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