Stiffening boxes

Proteins that bind the major groove but do not perturb the normal B-DNA structure can enhance CT efficiency in DNA. This was demonstrated by using the restriction endonuclease PvuII and the transcription factor ANTP [17]. As a result of the binding of proteins, the DNA conformation is stiffened, the conformational movements are reduced, and, as a result, CT is facilitated. In contrast with R.PvuII and ANTP, the TATA-box binding protein induces two 90° bends in the DNA... 

The employees returned on Sunday to complete the job. They decided to strengthen this poorly-constructed box by welding a 2-inch (5 cm) angle iron stiffener around the middle of the ill-designed box. After the angle iron improvement was completed, the mechanic closed the valve and moved away. It was a good thing he did move away rapidly, because the box quickly exploded. 

A match consists of a shank or stick of short, thin combustible material such as wood or resin-stiffened cardboard, tipped with flammable, solid materials, often phosphorus-based, along with binders, friction enhancers, and inert materials. When heated through friction or shock as the match is struck, the tips easily ignite with sufficient heat to cause the shank to combust. Strips of cardboard matches are stapled into blocks, books, or cards, while wooden matches are often distributed in boxes ... 

Adhesives. Box toe gum, for example, is a nitrocellulose adhesive used to stiffen the toe area of shoe uppers toe puffs),... 

One other mechanism appears to operate when fractioning paper and boxboard. The application of water to the surface will raise the coefficient of friction by lifting fibers out of the surface of the paper. If only water is applied, these fibers tend to go back into the surface if another box or paper bag is passed over its surface. However, if these fibers are coated with colloidal silica particles from the application, they are stiffened and strengthened and tend to remain upright creating a rougher surface. 

S. 1 Gussets in a Box In a box as shown in Fig. 4.42, a gusset would usually not be-required except to stiffen the side walls if they are very long. The stiftening effect of the end walls (sides) will often be enough to ensure the required stiffness of the bottom and sides of the box. 

Stress (strength) analysis and optimization. To reduce wall thickness and avoid local buckling of the plates, longitudinal and transverse T-stiffeners were added to the inside of the box... 

The spacing between the longitudinal stiffeners for the box-sections were designed to maintain a width to thickness ratio hit) that satisfied the Class 3 section requirements CSA S16-09 (2010), Equation 1. 

The stiffener and the effective width of box-section plate were considered a column or longitudinal strut supported between transverse T-stiffeners. The stiffened sections resulted in slenderness ratios (KLIr) of less than 115. The compressive resistance of the effective stiffener and plate section was compared to the computed axial stress due to the combined effects of bending md cixicil load. 

The tTcuisverse T-stiffeners welded to the inside of the box-column sections were considered to behave compositely with the box-section wall as a simply supported beam spanning from corner to corner. For analysis purposes the effective width of box-section acting with the T-stiffener was take equal to the width of the T-section. Two percent of the maximum compression force along the longitudinal struts (stiffeners) were considered as point loads acting on the transverse T-stiffened beam section. 

As required, transverse stiffeners were designed to provide additional shear resistance of the box section sides in order to support the rope breaking shear forces in the sheave beams. Cross-section shear capacity was determined in accordance with the requirements CSA S16-09, Clause 13.4. 

Figure 5. Box-section walls being assembled complete with stiffeners and access ladder...

Figure 6. Three Box-section walls assembled with stabilizing struts and stiffeners...

Each of the 4 Box Section wall panels, complete with transverse and longitudinal stiffeners, ladders/platforms and lighting were assembled (Figure 5). 

Fig. 8-11. A double-walled, box-like structure in which the bottom members are stiffened by egg-crate ribbing the sides are stiffened by vertical ribs.

For the calculation of noise transmission into the enclosure, a simplified model shown in Fig. 4 has been chosen. A cantilever box beam is attached to two stiffeners of the discretely stiffened sidewall. A random point couple is acting at the free end of the cantilever beam. The walls at z 0 and z = d of the acoustic enclosure are treated with absorbtive materials which are represented by the point impedance model as... 

---