INPUT ARTICLE: Article: Swamp coolers work best when the humidity outside is relatively low, making the dew point low. You can check the dew point on most weather apps and weather websites.  The dew point is the temperature at which the water in the air is evaporating and condensing at the same rate. You want a lower dew point because swamp coolers work by evaporating water in the air to cool the room down. The lower the dew point, the lower you can cool. Typically, you can cool down the air to 20 degrees above the dew point temperature without your home getting too humid.  You can also use a dew point calculator to calculate the dew point, such as this one: http://www.dpcalc.org/. You need to know the temperature and humidity. For swamp coolers to work, you need to let air out at the same rate that the swamp cooler is blowing air in. That way, humidity won't build up in your house, making it seem warmer than it actually is. Though opening windows seems counter-intuitive, it actually helps your swamp cooler work better.  You'll need 1 to 2 square feet (0.093 to 0.186 m2) of open window space per 1,000 cfm, which is the unit's cooling capacity. You don't want to open them too far because that lets in hot air.  The other option for ventilation is installing grills to the attic, if your attic has ventilation. To help direct the cool air where you want it, only open windows where you want the air to be cooler, as that will pull the cold air that direction. Keep the windows closed in areas you don't want to cool down. If the weather is nice outside but your house is a little warm, you can use most swamp coolers as a house-wide fan. Pick the vent-only option to cool down your house with outside air. Generally, swamp coolers have more than one speed. The higher speed will keep your home cooler, but the lower speed is more energy efficient. Pick the one that meets your needs.

SUMMARY: Operate the cooler when the dew point is under 55 °F (13 °C). Let the air out by opening a window or two. Close windows in areas you don't want to cool. Use the fan option when the weather is nice. Change the speed to your preference.


INPUT ARTICLE: Article: Begin by smiling at the person. Smiling makes you feel happier and more confident. It can make it easier to walk up to someone to start a conversation. Plus, when you smile, the person you're smiling at automatically wants to smile back.  Then, introduce yourself by saying "Hello" and giving your name.  Start with, "Hello, I'm Jessica. What's your name?" Bring up a topic to begin the conversation. In a conversation, both you and the person you're talking to need a chance to say something. You're exchanging information to learn about each other. For example, you could ask them about their favorite singer or what their favorite color is.  You could also start a conversation about what's going on around you. For instance, if you're in math class, you could say, "Is there a lot of homework this year?" If you're at lunch, you could say, "So what's your favorite food?" Smiling at people is a good way to show people you're open to friendship. You don't always need to be the person who says "Hello." Sometimes, other people will come up to you if you look approachable. Approachable just means you look like someone nice that another person could have a conversation with.  In other words, try not to cross your arms or look angry if you want someone to approach. Try to look happy and interested in other people. If someone comes up to say "hello," ask her to sit next to you. You could say, "I'm so glad you came over! Would you like to sit next to me?" When you're meeting someone new, you have to be able to hold a conversation. That means you need to both ask questions about the other person and answer their questions in return. It's a way of getting to know one another. It involves both giving to the conversation and actively listening to what the person has to say.  You could ask them, "What's your favorite food?" If they say, "Pizza!" you could say, "Pizza is my favorite, too! We made it at home last week." That way, you're offering something about yourself (what your favorite food is), as well as offering them something to respond to ("We made it at home last week.") They might say, "Really? I've never made pizza before. Is it hard?" Many friendships are based on the fact that you have common interests. That doesn't mean that you like all the same things. However, it does mean that you share some things that you both like. As you're talking to the person, try to figure out what things you both like. That way, you can develop those interests.  For example, you discovered you both have a love of pizza. That's a common interest! You could get pizza together, or you could even invite them over to your house to learn how to make pizza. You could say, "Since we both love pizza so much, maybe you'd like to come over sometime and make pizza with me." Use what you know about the person to ask questions about their life and interests. If you don't know very much about the person, ask questions to get to know them better.  For example, you could ask, "I saw you're on the dance team. How long have you been dancing?" Or, you could ask, "How's your project for our math class going? Mine is taking forever!"

SUMMARY: Start a conversation. Be approachable. Act friendly. Find common interests. Ask questions about your new friend.


INPUT ARTICLE: Article: A topographer is a newer version of the keratometer. Your doctor will have you sit at a table and look into a bowl. This bowl's inner surface is covered in a pattern of concentric rings. A digital camera sits at the base of the bowl and charts the cornea's surface by measuring the reflected pattern in the eye. This basically creates a contour map of your eye, and it’s an excellent technique for measuring irregular astigmatism.  Most corneal topography tests measure 8,000 to 10,000 points on the cornea, making it the most accurate keratometry test. Other advanced ways of measuring astigmatism include autorefractors that measure refraction, and the IOLMaster that makes extensive measurements of the interior and exterior of the eye. The IOLMaster is usually used before cataract surgery. The Placido disc is an old-fashioned, hand-held device that is shaped like a giant lollipop. The disc has several sets of concentric circles painted on one side, and is used to measure the regularity of your cornea’s surface. Your doctor holds the disc up to their own eye with the rings pointed towards you, and they look into your eye. Sit still and look straight ahead. The image of your cornea reflects back, and where there is irregular shape it makes the concentric rings look distorted to your doctor. This old-fashioned method can help to diagnose keratoconus, a disorder that causes irregular astigmatism due to thinning and protruding of the cornea. The shape of your posterior cornea (the back surface of the cornea) can influence the severity of your astigmatism. Keratometry can only measure the front of your cornea, but Scheimpflug imaging uses tomography to get more accurate readings of how thick your cornea is and what the back of it looks like. This method can be helpful in predicting how successful surgery may be in correcting your astigmatism.

SUMMARY:
Use a corneal topographer for more precise measurements. Try a Placido disc for irregular astigmatism. Use a Scheimpflug device to measure the posterior cornea.