Environmental Science And Human Populations Worksheet Essays

Environmental Science And Human Populations Worksheet Essays Environmental Science And Human Populations Worksheet Essay Environmental Science And Human Populations Worksheet Essay What would you include in a brief summary on the history of the modern environmental movement, from the 1 sass to the present? October 2, 1968 The Wild and Scenic Rivers Act, the National Trails System Act January 1, 1970 The National Environmental Policy Act (NEAP) April 22, 1970 The first national Earth Day February 17, 1981 President Reagan issues Executive Order; Office of Management and Budget (MOB) 20th anniversary of Earth Day 2. Explain the primary concern over exponential population growth. What promotes exponential population growth? What constrains exponential population growth? Population concern is about the balance between human needs and the resources available to meet those needs, now, and the future. Population has a constant birth rate through time and is never limited by food or disease, it as, exponential growth the birth rate alone controls how the population grows. 3. What is carrying capacity? Compare predictions for human population growth in developed countries versus developing countries. What will occur if carrying capacity is exceeded? The carrying capacity of a given ecosystem is the total number of organisms in a given species for which there are sufficient resources, so that they survive and reproduce. Developing countries have poor access to birth control, often reactive religions which prohibit birth control and value large families, and often have a lot of farmers, who benefit from having lots of children to help them work the land and take care of them in their old age. If carrying capacity exceeded warfare might occur. 4. How do individual choices affect natural ecosystem? Provide examples from your personal or community experience. Nearly every activity a person does affects the ecosystem, either positively or negatively. I live in the city, there are a lot of people, trash, buses, cars and transportation.

How to Paint Composite Materials

How to Paint Composite Materials Composite materials are mixtures of different fibers bound together by a hardening resin. Depending on the application, composite materials may or may not require painting. Painting is a good way to restore or change the color of the composite after the original finish has faded. The best methods of painting depend on the type of materials in the composite. Following are step-by-step instructions for painting some of the most common composites. You may also want to check with the manufacturers recommendations. Painting Fiber Cement Composites Use a pressure washer to clean. Wait two-four hours for the cement composite to dry.Apply a primer.Wait two hours or so for the primer to dry.Apply the paint same way you applied the primer. Wait about two hours for the paint to dry. Painting Wood Composites For exterior wood composites, use a pressure washer with a low-pressure tip to clean. Wait two hours for the composite to dry.For interior wood composites, dust with a broom.Using a roller, coat with an acrylic latex primer. Use a paintbrush for any areas you cant reach with a roller.Wait two hours or so for the primer to dry.Use satin or semi-gloss latex paint on interior wood composites. Use acrylic enamel on wood composites inside the house. Apply acrylic latex paint the same way you applied the primer. Wait four hours until dry. Painting Composite Decking Mix one part bleach with three parts water.Using rags, a roller, or a brush, apply the bleach solution liberally to all surfaces.After half an hour, scrub the surfaces.Rinse off the solution and residue.Using very fine sandpaper (220 grit) lightly sand all the surfaces.Wash off dust and dirt with a household detergent or commercial cleaner made for cleaning composite decks.Rinse thoroughly.If you are going to paint the deck, prime with an exterior latex stain-blocking primer made for plastic materials. Do not prime if you plan to stain the deck instead of painting it.For painting, use a high-quality latex floor and deck paint in a satin or semi-gloss finish. For staining, use a high-quality acrylic latex solid color deck stain recommended for composite decking. Painting Fiberglass Composites Fill holes or imperfections with fiberglass putty. Smooth out the putty with a putty knife. Let it cure completely.Sand with heavy sandpaper (100 grit) to remove excess putty or any paint. After the composite is fairly smooth, switch to 800 grit sandpaper and sand until the composite is very smooth. You can use an orbital sander or sand by hand.Use a dry rag and acetone to remove dust, grease, and debris.Apply a primer. Most primers work on fiberglass, but its a good idea to double check with the paint store on the best one to use. Wait two hours or so until the primer is dry.Spray or use a brush to apply the final coat of paint. Wait until the paint is dry.Apply another coat of paint or apply the clear coat. Always use a clear coat after the last coat of paint; it will seal the paint and help protect the paint from the elements. Final Words On Painting Composites As with any paint job, thorough preparation is the key to a good looking and long lasting paint job on composite materials. Follow recommended safety precautions on the products you use. For example, wear gloves when working with fiberglass. Wear liquid-resistant gloves using bleach. Wear eye protection when sanding, using bleach, and when working with fiberglass.