Acid Rain Essays (1631 words) - Chemistry, Matter,

Acid Rain What Causes Acid Rain? One of the main causes of acid rain is sulfur dioxide. Natural sources, which emit this gas, are Volcanoes, sea spray, rotting vegetation and plankton. However, the burning of fossil fuels, such as Coal and oil, are largely to be blamed for approximately half of the emissions of this gas in the world. When sulfur dioxide reaches the atmosphere, it oxidizes to first form a sulfate ion. It then Becomes sulfuric acid as it joins with hydrogen atoms in the air and falls back down to earth. Oxidation occurs the most in clouds and especially in heavily polluted air where other compounds such as ammonia and ozone help to catalyze the reaction, changing more sulfur dioxide to sulfuric acid. However, not all of the sulphur dioxide is changed to sulfuric acid. In fact, a substantial amount can float up into the atmosphere, move over to another area and return to earth unconverted. In the following pages I will show the effects of acid rain on: ? Effect on Trees and Soils ? Effect on Lakes and Aquatic Systems ? Effect on Materials ? Effect on Atmosphere ? Effect on Architecture ? Effect on Humans Effect on Trees and Soils One of the most serious impacts of acid precipitation is on forests and soils. Great damage is done when sulfuric acid falls onto the earth as rain. Nutrients present in the soils are washed away. Aluminium also present in the soil is freed and the roots of trees can absorb this toxic element. Thus, the trees are starved to death as they are deprived of their vital nutrients such as calcium and magnesium. Not all of the sulphur dioxide is converted to sulfuric acid. In fact, a substantial amount can float into the atmosphere, move over to another area and return to the soils unconverted. As this gas returns back to earth, it clogs up the stomata in the leaves, thus hindering photosynthesis. Research has been made where red spruce seedlings were sprayed with different combinations of sulfuric and nitric acid of pH ranging from 2.5 to 4.5. The needles of these seedlings were observed to develop brown lesions. Eventually, the needles fall off. It was also found that new needles grew more slowly at higher concentrations of acid used. Because the rate at which the needles were falling was greater than the rate at which they were replenished, photosynthesis was greatly affected, The actual way in which these needles were killed is still not yet known. However, studies have shown that calcium and magnesium nutrients are washed away from their binding sites when sulfuric acid enters the system. They are replaced by useless hydrogen atoms and this inhibits photosynthesis. Effect on Lakes and Aquatic Systems One of the direct effects of acid rain is on lakes and its aquatic ecosystems. There are several routes through which acidic chemicals can enter the lakes. Some chemical substances exist as dry particles in the air while others enter the lakes as wet particles such as rain, snow, sleet, hail, dew or fog. In addition, lakes can almost be thought of as the "sinks" of the earth, where rain that falls on land is drained through the sewage systems eventually make their way into the lakes. Acid rain that falls onto the earth washes off the nutrients out of the soil and carries toxic metals that have been released from the soil into the lakes. Another harmful way in which acids can enter the lakes is spring acid shock. When snow melts in spring rapidly due to a sudden temperature change, the acids and chemicals in the snow are released into the soils. The melted snow then runs off to streams and rivers, and gradually make their way into the lakes. The introduction of these acids and chemicals into the lakes causes a sudden drastic change in the pH of the lakes - hence the term "spring acid shock". The aquatic ecosystem has no time to adjust to the sudden change. In addition, springtime is an especially vulnerable time for many aquatic species since this is the time for reproduction for amphibians, fish and insects. Many of these species lay their eggs in the water to hatch. The sudden pH change is dangerous because the acids can cause serious deformities in their young or even annihilate the whole species since the young of many of such species spend a significant part of their life cycle in the water. Subsequently, sulfuric acid in water can affect the

What to Do the Week Before the SAT if You Havent Prepared At All

What to Do the Week Before the SAT if You Havent Prepared At All This is it. You have exactly one week before you head to the testing center and take the SAT. You have not prepared at all before now, and you only have one week - just seven short nights - before you take the test that can help or hurt your chances of getting into the college or university you are  dying  to get into. So, what do you do the week before the SAT that can make any sort of difference in your score? Cram like a maniac? Completely forget about looking at test prep material at all because, after all, what good would it do? Reschedule your SAT? Have a panicky meltdown in the cereal aisle of Target?   Before you get any crazy ideas, take a peek at the things you  should  be doing to get yourself ready this week so you have a shot at getting a good score on test day.   Go Immediately to a Bookstore and Buy an SAT Test Prep Book Go to the store and pick up a test prep book for the SAT. Choose one from either The Princeton Review, Kaplan Test Prep or The College Board. The Princeton Review is the most readable, so Id start there. Make sure the book you buy is for the Redesigned SAT, the test that took over for the old SAT in March of 2016. There will be nothing worse than prepping for a test that no longer exists.   Go To KhanAcademy.org  and Take an SAT Practice Test The Khan Academy has partnered with The College Board, the makers of the SAT test, to provide students with free SAT practice tests to help you get ready for the exam. Ideally, you should have been using this site for the last four weeks to really hone your skills. However, there are still some things you can do on the site to get you better prepared for the test on Saturday. Before we do them, we need to know the areas in which you need the most help. So first, take a full-length practice SAT test. You will need to sign up with your Facebook or email account.   Pinpoint Your Weaknesses At this point, you must focus on the areas of the test in which youre the least proficient. That means, after you take the practice test and the Khan Academy scores it for you, write down or print out the area scores that were the lowest. Was it Math? Great. Youll be zeroing in on that. Youll need to focus on your weaknesses- and exclusively on them- most of this week.   Strengthen Your Weaknesses Since youve narrowed down the areas of primary concern, you need to start pumping them up! Again, go to the Khan Academy website, and complete the practice problems for the areas that you were the weakest, Likewise, go to your test prep book and read through the sections and complete the practice problems in those weak areas. Youre going to spend 4-5 days working on these sections to really boost them up as much as possible. Check out your Strengths   After youve really nailed down your weakest section, spend one day learning about the sections of the test where you scored the highest. Was it  reading? Or writing? Read through the test directions, the content youll need to know, and complete as many practice questions as you possible can. Write a Practice Essay If you havent already, write a timed SAT essay using one of the prompts from the test prep book. Although the essay isnt figured into your overall score and is no longer a required feature of the SAT exam, many colleges and universities still require it and may use it to assess your overall readiness for the program in which youre interested. At the very least, youll get a refresher on writing an essay in a short amount of time.   Take One More Practice Test This time, try to simulate the test-taking experience as much as possible, and take the paper practice test in the back of the book. Sit at a desk in a quiet room. Set a time-limit just like youd have on test day, and work through the problems with efficient test-taking strategies. Dont you dare cheat by getting up in the middle of the test or guzzling a soda in the middle of it, either. Its good to practice disciplining yourself to sit and focus.   Get All Your Stuff Ready The Night Before There are several things you need to do the night before the SAT. First, be sure you have your admission ticket and photo ID ready to go. Then, check for test center closings and plan out your route to the testing center. Set your clock. Get your clothes ready so youre not scrambling in the morning. Want the complete list? See it here.   Relax the Night Before At this point, youve done everything you can do to get ready for the SAT in the limited time youve provided yourself. So...relax. Go out to dinner with your family. Watch an EARLY movie and hit the sack EARLY so you can be bright and refreshed for that early morning wake-up call. You can sabotage all of the hard work youve put in by doing something silly like going out or partying the night before the SAT.

Guerilla marketing technics Essay Example | Topics and Well Written Essays - 2500 words

Guerilla marketing technics - Essay Example The concept of Trust has widely emerged; however, this has inclined branding associations to becoming a central to competition. Modern contemporary marketing technology has been its focus upon the creation of differentiated brands. Brand image according to Hagel & Armstrong (1997) is seen as a means of aiding a consumer in the categorization of product offerings. It has also been argued that a number of elements of the brand have facilitated consumer's access to brand value as a route to categorization. De Cheratony & Dall' Olmo Riley (1998). Brand comprises meanings drawn from two distinct sources namely brand identity as coined and communicated by the brand engineer and concurrently brand meanings from the consumers point of view. In a nutshell branding could be viewed as the spectrum continuum of consumerisation that begins from the primitive selling focus of a commodity market, until it finally develops into the concept of brands as competition heightens With further intensification of competition, classic branding has emerged as brands have developed personalities. Post-modern marketing brings with it socially constructed brand meanings and increasingly cynical consumers who construct their own brand identities. ... derable evidence that, ontologically speaking, brands exist whatever definition of the brand is developed or chosen, and regardless of whether it is in a physical or virtual environment. Consequently, Trust can be defined as "the willingness of a party to be vulnerable to the actions of another party based on the expectation that the other will perform a particular action important to the trust or, irrespective of the ability to monitor or control that other party". The rapid development of e-commerce in last decade has envisioned and expanded the trust research in the context of e-commerce. More specifically, researchers found trust very important, especially, in the relationships between consumers and e-vendors (Ratnasingham 1998; Merrilees & Frye 2003). Thus several concepts of consumer's trust in e-commerce have been introduced during the decade (Tan & Thoen 2000-2001; Lee & Turban 2001; McKnight et al. 2002; Gefen et al. 2003; Tan & Sutherland 2004; Kim et al. 2005). According to these formulations and earlier research, three major elements of e-trust can be identified. These are inter-personal, institutional, and dispositional trust. Next, all these three elements are discussed in detail. Interpersonal trust means individual's trust toward another specific party or the trustworthiness of the third party Tan & Sutherland (2004). More specifically, the concept of interpersonal trust in e-commerce stresses consumer's trust toward e-vendor The concept of consumer trust in e-commerce Trust is a widely studied phenomenon across disciplines. Traditionally, researchers in the fields of psychology, sociology, social psychology, economics, and marketing have been interested in trust as an important factor affecting human behavior and relationships between different