Mac Hdd Fan Control Crackl
Beaulah Mozie
Tried various sounds options in Windows and also disconnected/reconnected bluetooth but still crackling. I don't get any crackling with Battlefield, YouTube or MP3 song files. Only in DCS it seems though it never happened before 2.5.6.
I am working on a flat slab design.
For the bending moment, the provided reinforcement matches my hand calcs. However when i activate the option to control the crack width with additional reinforcement then the provided reinforcement is higher than what i expect from the hand calculations.
For crack width 0.2mm and BM (Quasi Permanent combination) (412 KNM/M) I expect 6400 mm2/m reinforcement
The results i get from the model is 9400 mm2/m reinforcement
Attached the model and the detailed calcs
Cracks in buildings and building materials normally result from restrained movement. This movement may originate within the material, as with volume changes due to moisture loss or acquisition, temperature expansion or contraction, or may result from movements of adjacent or supporting materials, such as deflection of beams or slabs. In many cases, movement is inevitable and must be accommodated or controlled.
Designing for effective crack control requires an understanding of the sources of stress which may cause cracking. It would be a simple matter to prevent cracking if there were only one variable. However, prevention is made more difficult by the fact that cracking often results from a combination of sources.
There are a variety of potential causes of cracking. Understanding the cause of potential cracking allows the designer to incorporate appropriate design procedures to control it. The most common causes of cracking in concrete masonry are shown in Figure 1 and are discussed below.
Although mortar, grout, and concrete masonry units are all concrete products, unit shrinkage has been shown to be the predominate indicator of the overall wall shrinkage principally due to the fact that it represents the largest portion of the wall. Therefore, the shrinkage properties of the unit alone are typically used to establish design criteria for crack control.
Composite walls are multi-wythe walls designed to act structurally, as a single unit in resisting applied loads. The wythes are typically bonded together using wall ties at prescribed intervals to assure adequate load transfer. When the composite wall includes a clay brick wythe bonded to a concrete masonry wythe, ladder-type joint reinforcement, or box ties are used to provide some degree of lateral movement between wythes. In addition, expansion joints are installed in the clay brick wythe to coincide with control joints in the concrete masonry wythe.
When clay brick is used as an accent band in a concrete masonry wall, or vice-versa, the differential movement of the two materials may result in cracking unless provisions are made to accommodate the movement. To reduce cracking, slip planes between the band and the surrounding wall, horizontal reinforcement or more frequent control joints or a combination thereof can be used to control cracking. See Crack Control for Concrete Brick and Other Concrete Masonry Veneers (ref. 6) for more information on these approaches.
All wall systems are subject to potential cracking from externally applied design loads due to wind, soil pressure or seismic forces. Cracking due to these sources is controlled by applying appropriate structural design criteria such as allowable stress design or strength design. These criteria are discussed in detail in Allowable Stress Design of Concrete Masonry and Strength Design Provisions for Concrete Masonry (refs. 1 and 9).
Traditionally, crack control in concrete masonry has relied on specifying concrete masonry units with a low moisture content, using horizontal reinforcement, and using control joints to accommodate movement. Prior to the 2000 edition of ASTM C90 (ref. 8), low moisture content was specified by requiring a Type I moisture controlled unit. The intent was to provide designers an assurance of units with lower moisture content to minimize potential shrinkage cracking. However, there are several limitations to relying on moisture content alone since there are other factors that influence shrinkage which are not accounted for by specifying a Type I unit. Additionally, Type I units were not always inventoried by concrete masonry manufacturers. Most importantly, Type I units needed to be kept protected until placed in the wall, which was proven to be difficult on some projects. Because of the above problems associated with the Type I specification, ASTM removed the designations of Type I, Moisture-Controlled Units and Type II, Nonmoisture Controlled Units from the standard.
Control joints are essentially vertical separations built into the wall to reduce restraint and permit longitudinal movement. Because shrinkage cracks in concrete masonry are an aesthetic rather than a structural concern, control joints are typically only required in walls where shrinkage cracking may detract from the appearance or where water penetration may occur. TEK 10-2C (ref. 4) provides much more detailed information on control joint details, types and locations.
The net effect is that reinforcement controls crack width by causing a greater number (frequency) of cracks to occur. As the horizontal reinforcement ratio (cross-sectional area of horizontal steel vs. vertical cross-sectional area of masonry) increases, crack width decreases. Smaller sized reinforcement at closer spacings is more effective than larger reinforcement at wider spacings, although horizontal reinforcement at spacings up to 144 in. (3658 mm) is considered effective in controlling crack widths in some areas.
Studies have shown that reinforcement, either in the form of joint reinforcement or reinforced bond beams, effectively limits crack width in concrete masonry walls. As indicated previously, as the level of reinforcement increases and as the spacing of the reinforcement decreases, cracking becomes more uniformly distributed and crack width decreases. For this reason, a minimal amount of horizontal reinforcement is needed when utilizing the NCMA recommended maximum control joint spacings (refs. 3 & 4).
Walls in high seismic areas with a relatively large amount of horizontal reinforcement may not require control joints, as the reinforcement alone reduces the width of shrinkage cracks to a size that can be treated effectively with water repellent coatings. Experience has shown that this can be accomplished in walls with at least 0.2% of horizontal reinforcement (ref. 3). See Table 1 for the size and spacing of reinforcement to meet this criteria.
Our home was new construction and the basement floor was poured around 1.5 years ago. The builder installed control joints in several locations in the basement slab. Several of these joints have widened. The widest crack is now around 1/8th inch wide with certain sections as wide as 3/16th inch wide. When i shine a flashlight down this wide section it looks as if i see gravel below although i'm not sure if that is just rough concrete since the floors are supposed to be 4 inches thick.
I play music using Virtual DJ and broadcast to a shoutbox server. I control the software using a Denon MC3000 controller but the audio is routed through a focusrite scarlett and into an Allen and Heath Xone 62 external mixer. The output from that goes to my home amp/speakers and simultaneously looped back into the scarlet and back to my Asus laptop where it is broadcast and recorded by audacity. I also have a microphone Sure 58 which is connected to the xone 62 mixer.
I play music using Virtual DJ and broadcast to a shoutbox server. I control the software using a Denon MC3000 controller but the audio is routed through a focusrite scarlett and into an Allen and Heath Xone 62 external mixer. The output from that goes to my home amp/speakers and simultaneously looped back into the scarlet and back to my Asus laptop where it is broadcast and recorded by audacity.
We examine the effect of small, spatially localized excitations applied periodically in different manners, on the crackling dynamics of a brittle crack driven slowly in a heterogeneous solid. When properly adjusted, these excitations are observed to radically modify avalanche statistics and considerably limit the magnitude of the largest events. Surprisingly, this does not require information on the front loading state at the time of excitation; applying it either at a random location or at the most loaded point gives the same results. Subsequently, we unravel how the excitation amplitude, spatial extent, and frequency govern the effect. We find that the excitation efficiency is ruled by a single reduced parameter, namely the injected power per unit front length; the suppression of extreme avalanches is maximum at a well-defined optimal value of this control parameter. analysis opens another way to control the largest events in crackling dynamics. Beyond fracture problems, it may be relevant for crackling systems described by models of the same universality class, such as the wetting of heterogeneous substrates or magnetic walls in amorphous magnets.
Contraction/control joints are placed in concrete slabs to control random cracking. A fresh concrete mixture is a fluid, plastic mass that can be molded into virtually any shape, but as the material hardens there is a reduction in volume or shrinkage. When shrinkage is restrained by contact with supporting soils, granular fill, adjoining structures, or reinforcement within the concrete, tensile stresses develop within the concrete section. While concrete is very strong in compression the tensile strength is only 8 to 12 percent of the compressive strength. In effect, tensile stresses act against the weakest property of the concrete material. The result is cracking of the concrete.
There are two basic strategies to control cracking for good overall structural behavior. One method is to provide steel reinforcement in the slab which holds random cracks tightly. When cracks are held tightly or remain small, the aggregate particles on the faces of a crack interlock thus providing load transfer across the crack. It is important to recognize that using steel reinforcement in a concrete slab actually increases the potential for the occurrence of random hairline cracks in the exposed surface of the concrete.
The most widely used method to control random cracking in concrete slabs is to place contraction/control joints in the concrete surface at predetermined locations to create weakened planes where the concrete can crack in a straight line. This produces an aesthetically pleasing appearance since the crack takes place below the finished concrete surface. The concrete has still cracked which is normal behavior, but the absence of random cracks at the concrete surface gives the appearance of an un-cracked section.
Concrete slabs-on-ground have consistently performed very well when the following considerations are addressed. The soils or granular fill supporting the slab in service must be either undisturbed soil or well compacted. In addition, contraction joints should be placed to produce panels that are as square as possible and never exceeding a length to width ratio of 1.5 to 1 (Figure 1). Joints are commonly spaced at distances equal to 24 to 30 times the slab thickness. Joint spacing that is greater than 15 feet require the use of load transfer devices (dowels or diamond plates).