Stylesheet Practice 1

For the following excerpt, create stylesheet items for each potential stylistic issue. Assume the text is correct.

The average American household generates 15 pounds of household hazardous waste (HHW) each year. Our homes contain an average of 3 to 8 gallons of hazardous materials in kitchens, bathrooms, garages, and basements. A four-city study, conducted by the University of Arizona, found the following proportions of HHW in the waste stream:  household maintenance items 36.6 percent (paints, thinners, adhesives, etc.)  household batteries 18.6 percent  cosmetics 12.1 percent (includes nail polish and removers)  cleaners 11.5 percent (includes polishes and oven cleaners)  automotive items 10.5 percent (mostly motor oil)  yard items 4.1 percent (includes pesticides, pet supplies, fertilizers)  hobby/other 3.4 percent (pool chemicals, art supplies, etc.)  pharmaceuticals 3.2 percent These household hazardous wastes are sometimes disposed of improperly by individuals pouring wastes down the drain, on the ground, into storm sewers, or putting them out with the trash. The dangers of such disposal methods may not be immediately obvious, but certain types of household hazardous waste have the potential to cause physical injury to sanitation workers; contaminate septic tanks or wastewater treatment systems if poured down drains or toilets; and contaminate drinking water supplies below unlined landfills. They can also present hazards to children and pets if left around the house. Stylesheet Practice 2

For the following excerpt, creates stylesheets for each potential stylistic issue. Assume the text is correct.

Beverly High School in Beverly, Massachusetts, uses a system of solar photovoltaic flat-plate panels to generate its electricity needs. Currently, this system produces 100 kw, but could produce consider-ably more with some simple modifications. The Beverly photovoltaic system is made up of more than 3,000 panels. Each panel contains 10 photovoltaic cells. The photovoltaic array is made up of separate sub- arrays of photovoltaic modules deployed in rows on a southerly fac-ing slope. Each subarray is made from 3 standalone (but electrically integral) sections called panels, supported by a portable mechanical jack. Although the panels can be manually tilted to follow the path of the sun, they have been put in a stationary position that optimizes their exposure to the sun. Each panel measures 292 inches by 93 inches and contains 10 photovoltaic cells. The power generated by these panels is transmitted at 4160 v from the inverters and a step-up transformer to the main 4160 v utility feed line into the school. Separate meters are used to measure power bought from or sold to the local utility. At the optimum tilt angle—about 40 degrees—the array provides about 14% of the annual school load. This amounts to annual energy savings of between $8,000–$16,000. Stylesheet Practice 3

Launch

The Mars Polar Lander is scheduled to launch January 3, 1999, at about 3:20 P.M. Eastern Standard Time on a Delta II rocket from Space Launch Complex 17B at Cape Canaveral Air Station, FL. The Delta II is a model 7425 with two liquid-fuel stages augmented by four strap-on solid-fuel boosters, and a third-stage Thiokol Star 48B solid-fuel booster. At the time of launch, the lander will be encased within an aeroshell attached to a round platform called the cruise stage. Because the lander’s solar panels are folded up within the aeroshell, a second set of solar panels is located on the cruise stage to power the spacecraft during its interplanetary cruise. Shortly after launch, these hinged solar panels will unfold, and the spacecraft will fire its thrusters to orient the solar panels toward the sun. Fifty-eight minutes after launch, the 112-foot-diameter (34-meter) antenna at the Deep Space Network complex in Canberra, Australia, should acquire the Polar Lander’s signal.

Entry, Descent, and Landing

By the time it reaches Mars on December 3, 1999, the Polar Lander will have spent 11 months in cruise. Throughout the cruise, the spacecraft will be communicating with Earth using its X-band transmitter and the medium-gain horn antenna on the cruise stage. Preparations for the lander’s entry into the Martian atmosphere will begin 14 hours in advance, when the final tracking coverage of the cruise are used to mark off the main phases of the Mars Polar Lander mission. Stylesheet Practice 4

Preparations for the lander’s entry into the Martian atmosphere will begin 14 hours in advance, when the final tracking coverage of the cruise period begins. This is the final opportunity for ground controllers to gather navigation data before entry. About 18 hours before entry, software that normally puts the spacecraft in safe mode in reaction to unexpected events will be disabled for the remainder of the spacecraft’s flight and its descent to the surface. Traveling at about 15,400 miles per hour (6.9 kilometers per second), the spacecraft will enter the upper fringe of Mars’ atmosphere, as shown in Figure 1. Onboard accelero- meters, sensitive enough to detect G forces as little as 3/100ths of Earth’s gravity, will sense when friction from the atmosphere causes the lander to slow slightly. At this point, the lander will begin using its thrusters to keep the entry capsule aligned with its direction of travel. The spacecraft’s descent from the time it hits the upper atmosphere until it lands will take about 5 minutes and 30 seconds to accomplish. As it descends, the spacecraft will experience G forces up to 12 times Earth’s gravity, while the temperature of its heat shield will rise to 3000º F (1650º C).

About two minutes before landing, the lander’s parachute will be fired from a mortar (or small cannon) when the spacecraft is moving at about 960 miles per hour (430 meters per second) some 4.5 miles (7.3 kilometers) above the surface. Ten seconds after the parachute opens, the Mars Descent Imager will power on and the spacecraft’s heat shield will jettison. The first descent image will be taken 0.3 seconds before heat- shield separation. The imager will take a total of about 30 pictures during the spacecraft’s descent to the surface. About 70 to 100 seconds before landing, the lander legs will deploy; 1.5 seconds after that, the landing radar will activate. The radar will be able to gauge the spacecraft’s altitude about 44 seconds after it is turned on, at an altitude of about 1.5 miles (2.5 kilometers) above the surface.