Blog Archives

Finite Element Modelling: Staggered Approach

Posted by on 22/ 11/ 15

The monolithic approach of coupled phenomena implies identical space and time meshes for each phenomenon. This is not always possible, for various reasons. The coupled problems may have different numerical convergence properties, generally associated with different physical scales or non-linearities. For example, a coupled hydro-mechanical problem may need large time steps for the fluid diffusion prob­lem, in order to allow, in each step, fluid diffusion over a long distance (of the order of magnitude of the finite elements)...

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ANTINOISE PROPERTIES

Posted by on 22/ 11/ 15

Noise had been defined as “audible sounds of any acoustic kind undesired in par­ticular circumstances, which irrespective of their frequency and level, are harmful, bothersome, and possibly induce a disorder in the listener’s hearing organ and other parts of their organism” (Kucharski, 1979). Many research centers around the world have been dealing with the problem of noise, and numerous publications have dealt with the subject. A comprehensive review of publications addressing the subject of noise can be found in Sandberg and Ejsmont (1999).

A source of noise emits an acoustic wave, which is subject to reflection and par­tial absorption by the pavement. “Silent” pavements are those with reasonably high sound absorption capabilities...

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Insulating Plank and Beam Roofing

Posted by on 22/ 11/ 15

Insulating a plank-and-beam roof is a little different than other styles without exposed beams. Log End Cottage had a fairly steep roof, with a slope of about eight-in-twelve (8:12). In that home, the “beam” component consisted of full – sized recycled three-by-tens. We planked over this with ordinary one-inch planking from the sawmill, planed one side for regularity of thickness, as well as for smoothness and appearance on the exposed interior. To insulate, we created a “double roof.” On the topside of the planking, over each of the three-by-tens, we installed a plastic vapor barrier and then another rafter made from a full-sized two-by-six.

We insulated between the two-by-six rafters with fiberglass batt insulation, and then installed a second layer of one-by planking, upon which...

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BODEGA

Posted by on 22/ 11/ 15

The Bodega has a fireplace, a full bath and kitchen and a washer/ dryer beneath the counter. I don’t count the loft as square footage in this house because, with so much sloped ceiling, it doesn’t officially qualify as a habitable room. That said, with seven feet of ceiling height over more than 70 square feet, this heated loft provides a lot of usable space.

Square feet: 297

With add-on: 391 House width: 14’

House length: 24’

Porch: 6’ x 6’

Great Room: 9’ x 13 %’ Kitchen: 73/V x 8’

Bathroom: 7%’x5’

Addition: 7’ x 93/4’

Ceiling height: 7’ 6”

Loft height: 7’

-sizes are approximate

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STRAIGHT-FLIGHT STAIRS

Posted by on 22/ 11/ 15

Stairs and the stringers that support them come in different shapes and styles. Some stringers have a simple plumb cut at the top and a level cut at the bottom, with fixed cleats in between to hold the treads. Most stringers have notches cut in them where treads and risers are attached. Stringers that sit between walls and are hidden from view are called closed stringers. When they are exposed—and usually finished—they are called open stringers.

Like the gable roof discussed in Chapter 6, the straight-flight stairs covered in this chapter are basic and simple. At the same time, the skills necessary to build
them are common to all stairs, no matter how complex they may seem...

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Rivers, canals, and Hydraulic technology in China

Posted by on 22/ 11/ 15

In 329 BC, the army of Alexander the Great conquered Bactria and reached Samarcand, more than 4,000 km from Macedonia. At the same time, on the other side of the deserts of Taklamakan 3,000 km to the east, another warrior kingdom by the name of Qin began an astounding expension. A century later, while Alexandria of the Ptolemites was shin­ing its brightest and while Archimedes was discovering the principles of hydrostatics, this powerful of Qin was unifying an empire that spread across an entire continent. When the name of Qin appeared in the Occident, having passed from mouth to mouth across India, it had been transformed to become what we know as China.1

Relations between China and the Near East – the Silk Road

The worlds of ancient China and the ancient West were never truly isolated, ...

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Dimples are essential

Posted by on 22/ 11/ 15

Before you install the first panel on the ceil­ing, it’s important to understand how to fasten drywall to the joists, studs, and other framing members. Whether you’re using nails, screws, or both, you must leave a dimple in the panel with every fastener you drive. This small recess will later be filled with drywall compound as the wall surface is filled and finished. Screw guns can be set to pull the drywall panel tightly against the framing members and drive the screw just below the surface without breaking the face paper. If you’re driving nails instead of screws, your last hammer blow should push
the drywall tightly against the wood and set the head of the nail in a shallow dimple without breaking the paper surface (see the photo above).

Dead men are useful

Whether you have one he...

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SMA Compaction Enhancing Agents

Posted by on 22/ 11/ 15

Agents enhancing compactability by means of changing the temperature susceptibil­ity of a binder have been used in many countries. They enable the placement of a mix­ture at a lower temperature and make its compaction easier through the reduction of binder viscosity. Reduced binder viscosity enhances the compactability of a mixture, resulting in a decrease in the content of voids and an increase in the bulk density. In fact, it is this effect that can be seen in Figure 12.4, which shows example test results of a binder containing a Fischer-Tropsch (FT) wax. The application of an agent of this kind causes an increase in the bulk density of a mixture by about 15% in comparison with mixtures without this agent compacted at the same temperature...

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Getting Ready to Tile

Posted by on 22/ 11/ 15

If the substructure beneath the tile isn’t sturdy and stable, the job won’t last. Likewise, if walls aren’t plumb or floors aren’t level, tiles may adhere, but they may not look good. Start by assessing the existing surfaces. And that will inform your next steps, which can range from merely sanding finish surfaces to tearing out and reframing with studs and joists. The condition of existing floors, walls, and counters will also determine which setting bed you choose—and whether you should tile at all.

ASSESSING AREAS TO BE TILED

To check whether floors or countertops are level, use a long spirit level or a shorter level atop a perfectly straight board. Take several readings and use a pencil to mark individual high spots and dips. If variations from level exceed ‘A in. in 10 ft...

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Developing an Ecologically Sound Upholstered Furniture Line

Posted by on 22/ 11/ 15

While I was studying to become a certified Bau-Bi – ologist, I was captivated by Bau – Biologie’s philoso­phy. After much soul searching, I realized I wanted to incorporate its principles into the world of in­terior design, which had been my business for fif­teen years.

To create hea Ithy homes, I needed to be able to offer my clients healthy furniture, and at the time there was virtually nothing available. So in the fall of 2003 I approached Cisco Pinedo, owner of Cisco Brothers Corporation, a furniture manufacturer in Los Angeles, with the idea of producing a to­tally clean and healthy line of furniture. He readily agreed and we embarked on the lengthy journey of finding materials that would pass our stringent standards, based on the principles of Bau-Biolo – gie...

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