Category Archives: General Knowledge
Touring some of the local hobby shows and speaking with some of our younger customers, I’m finding a growing interest in robot building.
In routing around the Net I happened upon John Palmisano’s site, TheSocietyOfRobots.com
John offered me these thoughts on getting started and what’s available on his site:
Robots today are no longer only made out of traditional tin and steal.
Instead, an ever increasing number of robots consists of large
quantities of plastics – not just for aesthetic casings but also as
main structural components. Societyofrobots.com covers all aspects on
building your own robot, including materials and structural
* * *
So, Plasticguy says check’m out!
Fairfax folds on plastic bag ban
Bowing to threats of a lawsuit by the plastics industry, Fairfax officials have decided to make the town’s ban on plastic grocery bags voluntary. “Basically, we’ve gotten legal advice that we are not likely to prevail if we fight it,” said Councilman Lew Tremaine. “We don’t want to waste a bunch of people’s money, so we’re going to alter the ordinance so that it’s voluntary.”
In July, the council voted unanimously to bar grocery stores, restaurants and retail shops from using plastic bags. The ordinance, which did not require businesses to comply until Feb. 10, 2008, allowed the use of recyclable paper, compostable bags or reusable containers. Violators would have been fined $100 for a first offense, $200 for a second and $500 for any subsequent offenses. The town approved the ban over threats from the plastics industry, which argued that the ordinance amounted to an endorsement of paper bags, made from trees that consume greenhouse gases. An attorney for Emerald Packaging Co. and Fresh Pak Corp. accused Fairfax of ignoring the California Environmental Quality Act’s requirements for a full environmental assessment before enacting the ban.
“A big part of me thinks the whole concept that we have to do an EIR is patently absurd, and I’d love to see that dragon slain in a court of law,” Tremaine said. “But reality is reality.” Emerald Packaging representatives said the lawsuit would not move forward if the town follows through with plans to change the ordinance’s wording to discourage the use of plastic bags, but referred further questions to Donne Dempsey, managing director of the Progressive Bag Alliance, who said an EIR is in order.
“The increased use of paper would contribute to deforestation,” Dempsey said.
Fairfax faced similar opposition to its long-standing ban on polystyrene take-out containers. When the plastics industry threatened a lawsuit, environmental activists turned to Fairfax voters, who made the issue a ballot initiative. Tremaine said something similar is likely to happen with the bag ban.
“I think what’s going to happen is environmental activists are going to put it on the ballot. We’ve been down this road before,” Tremaine said. “The group I was working with at the time – the Fairfax and San Anselmo greens – did a petition drive and an initiative, and it passed by a ridiculously large margin.”
Andy Peri agreed.
“My understanding at this point is that we’ll be going to voters to collect the signatures necessary to get this on the ballot, probably in November 2008,” said Peri, a member of Green Sangha, the organization that initially pushed for the Fairfax ban. “Once it goes to the ballot, the plastic industry can’t play its shenanigans, making us do an assessment under CEQA law, when this ban is clearly in the interest of the environment, and in the interest of supporting clean air, clean water and wildlife.”
Because so many businesses have supported the ban, Peri said he doesn’t believe life in Fairfax will change once the council modifies its ordinance – which Tremaine said is likely to happen at its Nov. 7 meeting.
Hobby greenhouse helps gardeners stay busy year-round
The weather is clearly changing as nighttime low temperatures dip to the 40s and the tree leaves start to change colors and get ready for their autumn dance to earth. You can smell the cooler fall weather, and meteorologists are talking about wind chill temperatures again. The first frost and then the first freeze normally arrive in the next two or three weeks on the calendar.It’s time to start planning for any tropical or annual plants you want to save and bring inside for winter. Some plants may be too large to save, but you can take stem cuttings to root and carry over for spring. Most tropicals need to be kept near windows in good light if you are going to try to winter them in the house.
Many people look at the killing fall freeze as the end of a special season or memory and a chance for a clean palette to start their garden anew next spring. Others can’t bear to lose beloved plants, large porch or patio gardens, or special plant collections.
You can save a few plants in your house, but space and access to light often limit the number of plants you can bring in the house. This makes a hobby greenhouse the best option.
A hobby greenhouse can also be a fun way to produce vegetables through the winter, to grow seeds and cuttings, to start transplants for next spring or to start a collection of orchids, begonias, bonsai or the special plants of your choice.
You can buy a kit greenhouse at local stores or via the Internet, or you can build a greenhouse frame and cover it with a number of greenhouse skins or glazings. Decent kit greenhouses start at about $1,000 and go as high as $20,000. Most of the inexpensive kits are made of lightweight galvanized metal or polycarbonate extrusions and are covered with plastic film or single-wall polycarbonate panels. The frames go up in cost as the metal frame gets heavier or you switch to aluminum frames or painted frames. A few kits use redwood or cedar wood as the frame, but more than 85 percent of the kits sold use metal frames, which probably offer the most strength for the money.
The earliest types of greenhouses that used more glazed glass are still available but not used as often because of the glazing cost and because it takes more structure to support the glass. Glass is available in 1/8-inch-thick tempered glass and in energy-saving insulated glass panels. The most popular glazings these days are single-wall corrugated clear polycarbonate panels or the energy-saving twin-wall polycarbonate in 6- or 8-millimeter-thick panels.
Some kits still use corrugated fiberglass, and newer kits use the more expensive corrugated or twin-wall acrylic panels that will stay clear longer. Greenhouse-grade ultraviolet-resistant polycarbonate panels offer the most strength, durability and light transmission for the money.
Twin-wall panels save almost 30 percent to 35 percent in energy. Greenhouse copolymer plastic film is the least expensive glazing. When you install two layers and blow air between the layers, greenhouse plastic film is one of the most energy-efficient choices.
If you build your own wood or metal frame or convert a garage, shop or other building, you can buy good greenhouse glazing to put on your frame. You can use 4-foot-wide corrugated polycarbonate panels that install by overlapping the panels and screwing them to the frame.
You will need heat in your greenhouse. A unit heater is usually the best choice. Natural gas is generally the cheapest commercial fuel, followed by propane. Electric heat is the cheapest to install but costs the most to operate.
Even if you only use the greenhouse in fall, winter and spring, you will need ventilation, as all greenhouse owners very quickly appreciate the power of solar energy. You can provide winter cooling with side and roof vents or with a motorized shutter on one end and an exhaust fan on the opposite end.
It is usually best to automate the ventilation on a thermostat, because we often need cooling near the middle of the day even in the winter. It is not unusual to have the fan come on to ventilate on a 40-degree or 45-degree day. If it is clear and sunny outside, it is possible for the greenhouse temperature to rise to more than 100 degrees because of solar radiation if you are not ventilating.
You will probably need to add shade cloth and an evaporative cooler if you want to use the greenhouse in summer.
Although you can buy hobby greenhouses from mail-order catalogs or over the Internet, I would encourage you to buy this specialized equipment locally for the best advice on frames, glazing materials, sizing, heating and cooling equipment and shade percentages for this area. There are several good suppliers in Oklahoma City and Tulsa that would be familiar with our area’s conditions to help you select the right hobby greenhouse for your application and crops.
Now is the time to plant pansies, viola, ornamental kale and cabbage and to select and plant spring flowering bulbs such as tulips, crocus and daffodils. This is also a great time to mulch your more tender hardy plants to help insulate their roots and protect them for the winter ahead.
Rodd Moesel serves on the Oklahoma Horticulture Industrial Council and the Oklahoma State University agriculture dean’s advisory committee. He is a former president of the Oklahoma Greenhouse Growers Association. E-mail garden and landscape questions to email@example.com.
A reader left a comment yesterday about careers in polymer engineering. Not really sure of what a polymer engineer is I did some digging and found the following at Penn State’s Department Of Chemical Engineering. Perhaps someone in the field might offer an article more specific to the job opportunities in the field.
WHAT DO POLYMER ENGINEERS DO?
Polymers are the most rapidly growing sector of the materials industry. As long ago as 1981, polymer production exceeded 24 million metric tons per year. No wonder–polymers are found in everything from compact discs to high-tech aerospace applications. As polymer production has grown, so has the number of people who work in this field. Today, it’s estimated that 50 percent of the chemical engineers and chemists in the United States work in the polymer industry.
Polymer engineers need to apply the traditional skills of chemical engineers, such as plant design, process design, thermodynamics, and transport phenomena, to various problems involving the production and use of polymers. Many of the engineers currently working in industry trying to solve thes problems have background in either chemical engineering or polymers. The Polymer Engineering Option in Chemical Engineering is designed to produce engineers with both sets of skills.
More than half the chemical engineers in the world work with polymers in one form or another. As a graduate of the Polymer Engineering option, your knowledge of polymers can give you an advantage when competing for chemical engineering jobs including:
- Process engineering in polymer-producing chemical companies
- Process engineering in polymer processing or fabrication
- Scale-up of new synthetic chemistry from laboratory development to pilot plant and large-scale production
- Research and product development in polymer synthesis (current hot topics include biodegradable polymers and compatibilizers for recycling polymers)
- Research and process development in polymer processing
- Learn the fundamentals of polymer technology from the basics of polymer chemistry, structure, synthesis, and processing to more advanced topics, including structure-property relationships and end-use polymer design
- Learn about polymer mechanical properties, the applications of polymeric materials, and how to choose the correct polymer for a particular application
- Learn about polymer rheology and processing–where transport phenomena enter into the polymer field
- Prepare for internships with polymer companies that have strong ties to the Polymer Science and Engineering program and the Department of Chemical Engineering
- Receive highly personalized instruction in courses with low student to faculty ratios
- Participate in the activities of the Polymer Science Club
42% of all plastics destined for extrusion
Slumping residential building and maturing applications pose a threat to growth, but demand for extruded plastic in the U.S. is still projected to expand by 2.8% annually to nearly 40 billion lb in 2011, according to a new study entitled Extruded Plastics from The Freedonia Group (Cleveland, OH). Total market value in terms of final product cost is projected to reach $81.3 billion according to the report, driven in part by expected advances in extrusion’s cost efficiency, processing easy, and machinery improvements. Extrusion as a process will remain the largest consumer of plastics, converting 42% of resin in 2011.
Freedonia forecasts that polyvinyl chloride (PVC) and low-density polyethylene (LDPE) will account for the lion’s share of the business, taking up 60%. PVC is expected to grow 2.4% annually, driving by high-volume construction applications in pipe, siding, and flooring, with faster growth expected in LDPE on the basis of its use in food packaging. Polypropylene will offer the strongest growth, driven by the sheet and film markets. High-density PE is expected by grow 3.4% annually, but polystyrene will contract, giving ground to polyolefins and polyesters in food packaging. That market, combined with construction, accounted for 78% of all extruded plastics demand in 2006. For more information, go to www.freedoniagroup.com.—firstname.lastname@example.org
Through years of R&D, Reynolds Polymer Technology has developed an ability to chemically bond acrylic, creating a nearly invisible seam, while maintaining over 90% of the parent materials strength.
For larger projects, “on-site bonding” has become a way of creating massive acrylic structures on-site as shipping the finished product would be impossible. In some cases months are spent in clean room environments in order to create that exacting bonding atmosphere as would be at home.
Sudbury Neutrino Observatory Project
Sudbury, Ontario, CanadaThe Sudbury Neutrino Observatory in Ontario, Canada, is a scientific masterpiece. Designed for astrophysics research, this forty-foot (12.2m) sphere is made of 2″ – 4″ (5cm – 10cm) thick acrylic, was created with over 1,550 feet (470m) of bonds, and was constructed 1.25 miles (2km) beneath the surface of the earth in a clean room environment.
The Sudbury Neutrino Observatory was a collaborative effort sponsored by the United States, Canada and the United Kingdom to increase the scientific understanding of particle physics and astrophysics. Approximately 74,000 pounds (33,566kg) of acrylic and over 1,550 feet (470m) of bonds were used to create this 40’ (12.2m) cast acrylic sphere.
The forty-foot (12.2m) diameter seamless acrylic sphere at the Sudbury Neutrino Observatory Project is used for astrophysics research. Reynolds Polymer Technology provided the scientific research and design, engineering, manufacturing and on-site installation of the Sudbury Neutrino Observatory (SNO) project.
Copyright ©2007 R-Cast™ is a registered trademark of Reynolds Polymer Technology, Inc. All rights reserved.