Blog Archives

Light-Emitting Diodes Are the Future

Posted by on 25/ 11/ 15

LEDs are a Silicon Valley technology, manu­factured in a clean room, just like a comput­er chip. Electrical current runs through the 1-sq.-mm chip, exciting the electrons and creating light. A small bulblike cover focuses the light. LEDs can’t actually produce white light; white light must be created either by combining colors or by using a phosphor coating inside the bulb.

The lighting industry is betting heavily on forging ahead with significant advances in white-light LED technology in the next few years. Many of today’s LEDs, however, already perform well when used in the ap­propriate location.

Подпись:Manufacturers describe LEDs as cool – operating lamps. While it’s true that the lit end of an LED is cool to the touch, the semiconductors do produce heat...

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Earthworks Drains

Posted by on 25/ 11/ 15

This kind of drainage is installed with the aim of controlling waters emerging from earthworks, which includes not only the water that appears at the base of the exca­vations but also the flow coming from excavated slopes. Five types of systems can be used:

13.4.4.1 Drainage Layers

These consist (see Sections 13.3.4 and 13.3.6) of a layer of granular material with constant thickness (normally between 0.40 and 0.60 m) that is spread at the base of the excavation along the formation, or, for an embankment situation, at its foun­dation (Fig. 13.19). This layer is placed between geotextiles having separation and filter functions.

Fig. 13.19 Drainage layers

At the base of large embankments crossing deep valleys, the main aim may be to keep the water table at its original position in the...

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Whidbey

Posted by on 25/ 11/ 15

The Whidbey’s main floor is simi­lar to that of the B-53 and Enesti, except that it uses a bump-out to house a downstairs bedroom, and it has a full main floor bathroom, in­cluding a sink over the toilet. Pic­tured below is the add-on version with 2 bedrooms. I do not count the upstairs 400+ square feet be­cause, with so much sloped ceil­ing, it does not officially qualify as a habitable room. 1

Square feet: 63

House width: 7’ House length: 10’ Ceiling height: 9’ 6” – sizes are approximate
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MOUND SYSTEMS

Posted by on 25/ 11/ 15

Mound systems, as you might suspect, are septic systems that are constructed in mounds that rise above the natural topography. This is done to compen­sate for high water tables and soils with slow absorption rates. Due to the amount of fill material to create a mound, the cost is naturally higher than it would be for a bed system.

Подпись: FIGURE 14.9 ■ Cut-away of a mount-type septic system.

Coarse gravel is normally used to build a septic mound. The stone is piled on top of the existing ground. However, topsoil is removed before the stone

is installed. When a mound is built, it contains suitable fill material, an ab­sorption area, a distribution network, a cap, and topsoil. Due to the raised height, a mound system depends on either pumping or siphonic action to work properly...

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RESILIENT FLOORING

Posted by on 25/ 11/ 15

Vinyl and linoleum are the two principal resilient materials, available in sheets 6 ft. to 12 ft. wide, or as tiles, typically 13 in. or 12 in. square. Linoleum is the older of the two materials, patented in 1863. It may surprise you to learn that linoleum is made from raw natural materi­als, including linseed oil (oleum lino, in Latin), powdered wood or cork, ground limestone, and resins; it’s backed with jute fiber. (Tiles may have polyester backing.) Because linoleum is comfortable underfoot, water resistant, and durable, it was a favorite in kitchens and baths from the beginning; but it fell into disfavor in the 1960s, when it was supplanted by vinyl floor­ing, which doesn’t need to be waxed.

However, linoleum has proven resilient in more ways than one by bouncing back from near­exti...

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Electromagnetic Fields: Challenging Unsafe Limits

Posted by on 25/ 11/ 15

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Take on the military, government, electric utili­ties, appliance and cell-phone manufacturers, and the owners of television, radio, and other high fre­quency antennas and you’re in for a major fight. The stakes are huge because since 2003 insurance companies no longer cover eventual (because still unproven) damages caused by electromagnetic fields (EMFs). These are emitted by all from the smallest electrical devices and grounding circuits to high-tension power lines and radar systems.

"Scientists who have persisted in publicly rais­ing the issue of harmful effects of any portion of the electromagnetic spectrum were discredited, and their research grants were taken away," says orthopedic surgeon Robert O. Becker...

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A. Balance-Beam 0 Secondary Rafters

Posted by on 25/ 11/ 15

We had the same deck situation upstairs as downstairs: planking span was starting to get rather extreme about six feet from the main building. But, this time, we could use a simple and rather elegant solution not available downstairs: short secondary rafters. They are, I suppose, a kind of double cantilever, but 1 think the term “balance beam” paints a more accurate picture. Have a peek, again, at the rafter plan, Fig. 3.2 on page 109. The four five-foot-long (1...

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The Mills of the Middle Ages

Posted by on 25/ 11/ 15

The death throes of the aqueducts and the end of the Roman way of life

With the fall of the Roman Empire, the Romano-Hellenistic urban lifestyle in the West begins to retreat rapidly. The roots of this lifestyle are found in the Cretan cities of the Bronze Age. The forums where citizens met to discuss the business of the city are among the victims of the inward-turning that characterized this troubled period. The thermal baths where water so freely flowed disappear; the beautiful public fountains dry up. The cities degrade; new urban streets are unpaved and have neither sewers nor water pipes. Water is no longer delivered, it must be drawn from wells or from the river. This is likely why Lyon, for example, moves down from the heights of Fourviere to the banks of the Saone.

The aqueducts fa...

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AESTHETICS

Posted by on 25/ 11/ 15

Often, a detailed study is required to address the question of aesthetics. Alternative systems can be compared, with sketches, renderings, plan drawings, and other visual aids prepared to assist in the process. A multidiscipline team approach is desirable, including design engineers, planners, landscape architects, and environmental personnel. Public input to the selection system helps achieve acceptance of the final system. Designers should be concerned with the visual impact from both the driver’s side and the land user’s side of the wall.

Some of the important aspects of aesthetics include scale relationship, relationship to environmental setting, line form, color, and texture...

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Magnetic Fields

Posted by on 25/ 11/ 15

The importance of checking the electrical instal­lation under load with a gaussmeter before oc­cupancy is demonstrated in this case study. An electromagneticallysensitiveclient consulted with John by telephone throughout the construction of her home, which was built according to specifi­cations similar to those outlined in this book. After the client moved into her new home, she began experiencing symptoms that occur when she is exposed to elevated magnetic fields, such as ring­ing in the ears and inability to concentrate. Using a gaussmeter, she discovered that about half of the home registered over 5 milligauss. She called John in a state of panic, convinced that her house was ruined and that she would never be able to live in it.

John contacted the client’s electrician and of­fered ...

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