Saturday, January 25, 2020
Investigating the Energy Released of Ethanol and 1-pentanol
Investigating the Energy Released of Ethanol and 1-pentanol 1.0 Introduction Combustion reactions are always exothermic, due to the substances (fuels) releasing energy through combustion (temperature increases), which the change in enthalpy () is negative value. All fuels of this experiment are alcohols ââ¬â ethanol, 1-pentanol and two mixtures of them with different ratios (90%:10% ; 80%:20%), which are the most common organic compounds. Alcohols contain the hydroxyl functional group (-OH) (Diagram 1) bonded to an alkyl groupââ¬â¢s carbon atom (Chemwiki, 2014). The classification of alcohols depends on the number of carbon atoms are attached to the carbon atom that is attached to OH group. Both ethanol and 1-pentanol are primary () alcohols, which only one carbon atom is attached to the carbon atom with the OH group (Chemiwiki, 2014). Secondary () and tertiary () alcohols are when two and three carbon atoms are attached to the carbon atom with OH group, but they would not be used in the experiment. In this experiment, 1-pentanol () (Diagram 2) has the longest carbon chain (five carbon atoms) of the fuels, which is expected to produce the highest amount of heat during combustion (), and ethanol () (Diagram 1) has the lowest number of carbon atoms (two carbon atoms), which is believed to release low energy during combustion (). During combustion, the fuel/alcohol reacts with oxygen which produces carbon dioxide and water vapour. It is believed that the greater the change in enthalpy value, the more efficiency of the fuel and more energy will be released. The energy released is calculated through bond energy and measured data, which the heat of combustion of water is divided by the number of moles of the fuel used (). All fuels used in the experiment are hydrocarbon, which is when the carbon atoms joining together form different bonds. There are three main groups of bonding types (Diagram 3): alkanes, alkenes, and alkynes (Encyclopedia Britannica, 2015). Ethanol and 1-pentanol are both alkanes, that they only contain single bonds between carbon atoms; whereas, alkenes and alkynes group contain double and triple bonds between the carbon atoms. The calculated enthalpy change of energy is only an approximation, as the bond energy value for each bond is only an average. In addition, the bond energy value provided for each bond is measured in various states for different situations. This accounts for the difference between the calculated and the actual (Harcourt Education, 2007-2010). 4.0 Discussion 4.1 Analysis By investigating the energy produced during the combustion of different fuels, a linear increasing relationship (Figure 3) was discovered that the longer the carbon chain lengths (larger molar mass) in each fuel molecule, the higher energy released during combustion. Due to two of the fuels being mixtures, the number of carbon was hard to define; hence, the molar mass was used to compare with the average enthalpy. According to Figure 2, the average enthalpy and the fuelsââ¬â¢ molar mass had a linear relationship, that the larger molar mass of the fuel, the higher the heat of combustion. Ethanol had the lowest molar mass of 46.069g and 1-pentanol had the highest molar mass of 88.15g (Table 2), hence ethanol had the lowest average heat of combustion (668.6403kJ/mole) whereas 1-pentanol had the highest value (1588.2183kJ/mole) (Table 1). There was a large percentage increase of 137.53% from ethanol to 1-pentanol, which supported the increasing trend and the significant difference in Figure 2. Since a longer carbon chain lengths contain more C-H and C-C bonds (more bond energies) which produce more C=O and O-H bonds ( and ); more bonds would be needed to break and larger level of energy released. Figure 1 clearly illustrated that the secondary and calculated data both supported the increasing trend as the blue and orange bars continued to rise with the increase in molar mass. Thus, 1-pentanol was expected and justified to be the most efficient fuel for this experiment. Mixtures of ethanol and 1-pentanol were used to explore whether ethanol would have a great impact on 1-pentanol and the mixture with ratio of 90% ethanol and 10% 1-pentanol was expected to be the most efficient fuel in real life context. Through calculations, both mixtures had larger values of heat of combustion than pure ethanol; hence, ethanol had an impact on 1-pentanol as the percentage change of the mixture with 10% of 1-pentanol was 22.78% and 20% of 1-pentanol mixture was 39.40% in comparison to pure ethanol. Theoretically, the percentage change of the mixture with 20% of 1-pentanol should be more efficient than the mixture with 10% 1-pentanol due to it produced more energy, which it did have a higher value of energy (933.9340 kJ/mole) released than the other mixture (820.9308 kJ/mole). However, the Australian Government regulations would have a proportion of 10% ethanol in petrol (Biofuels Association of Australia, 2014), due to most petrol used in gasoline and diesel engines (in Australia) have an expansion ratio of 10:1 for premium fuel or 9:1 for regular fuel, and some other engines have ratios of 12:1 or higher (Wikipedia, 2015). Therefore, although the mixture with 20% 1-pentanol had higher efficiency than mixture with 10% 1-pentanol, the hypothesis was justified that the mixture with a ratio of 90% ethanol and 10% 1-pentanol was a more efficient fuel for petrol because it had a more most efficient ratio in real life, whereas the mixture with ratio of 80%:20% would be not as effective and may require different design/structure of engine or cause damage to the engine. 4.2 Evaluation The trials of the experiment were completed with consistency, although heat loss occurred, the increasing trend still applied through measured, secondary and calculated data. Moreover, heat loss occurred throughout the whole experiment which justified the consistency, thus the experiment was valid. From Table 3, the average percentage error showed that the mixture with ratio of 80%:20% was the most accurate fuel with lowest percentage error (44.74%) and pure 1-pentanol was the least accurate and had the highest percentage error (50.35%). All percentage errors were mainly caused by heat loss, which was probably due to incomplete combustion occurring during combustion as some black substances were on the bottom of the small cans after burning, which would have reduced the fuel efficiency so more mass of fuel was used. The insufficiency of oxygen caused incomplete combustion to produce carbon monoxide and water vapour, which could be avoided by washing off the char on the can after use each time to ensure the fuel efficiency in the next trial. Fibreglass was used as insulator wrapped around outside the big can, it could be improved by wrapping another layer of cellulose insulator (mainly made of shredded newspaper and mixed with several of chemicals to reduce its flammability) for the next experiment to increase energy efficiency. Fibreglassââ¬â¢ main weakness is that its incapability of blocking air from passing though, whereas cellulose insulator has higher density which would limit the air movement and prevent air-leakage better (Binford C, 2011). The non-consistency of the flame may have reduced the fuel efficiency as well, due to the flame was not stable while burning, but this could be overcome by conducting the experiment with a diminished-scale of compartment and calorimeter (over the top of the flame and cans) to investigate the maximum heat released rate and the combustion efficiency. The precision between all trials of pure ethanol, 1-pentanol and the mixture with 10% of 1-pentanol were good as the results of mass used of fuels were consistent. However, there was a big anomaly due to heat loss, occurring in the second trial of the mixture with 20% of 1-pentanol that the mass of fuel used was 0.65g, which was approximately 9.25% higher than the other two trials. The anomaly may be due to the air-conditioning was just starting which affect the room temperature and the temperature around the flame. This could be improved by completing the experiment at a certain room temperature with no air-conditioning, and it would keep the consistency of surroundingââ¬â¢s temperature. The experiment could be extended by changing the percentage of ethanol (e.g. 10% of ethanol), based upon the Australian Government that most petrol have 10% ethanol because at this ratio ethanol produces the most efficient energy (justified in Analysis). It could be extended by using mixtures rat io of 50%:50% of ethanol and 1-pentanol to explore which fuel would have a greater impact, as well as mixtures with ratios of 10%:90% and 20%:80% of ethanol and 1-pentanol to investigate whether mixture with 10% of ethanol had the most fuel efficiency. Another way to extend this experiment is to use different concentration of fuels used in the original experiment, by adding water or evaporating the fuel (heating ââ¬â increase the temperature) to decrease the concentration of fuels, then burn the fuels and calculate the mass of fuel used to then find the heat of combustion to investigate whether the trend of increase in carbon chain lengths/molar mass causes increase in the fuel efficiency still holds. 5.0 Conclusion In summary, the experiment was investigating the energy released of ethanol, 1-pentanol and their mixtures with ratios of 90% ethanol and 10% 1-pentanol and 80% of ethanol and 20% of 1-pentanol during combustion. Furthermore, the results of all fuelsââ¬â¢ energy released were shown to obey the trend of increasing in carbon chain length (molar mass) lead to the increase in energy released, and the mixture with ratio of 90%:10% was discovered to be the most efficient fuel ratio for petrol as the Australian Government uses. Therefore, the hypothesis was justified that pure1-pentanol was the most efficient but when relating to real life circumstances fuel mixtures containing a ratio of 90%:10% were the most efficient for petrol.
Friday, January 17, 2020
Icloud Current Situation Analysis
CURRENT SITUATION ANALYSIS Christopher Dobrinski Esra Arnaudova Evanzhelin Stoyanova Jora Cakuli Apple Inc. is an Americanà multinational corporationà that designs and sellsà consumer electronics, computer software, and personal computers. The company is widely recognized by its logo which is an apple that is bitten on the right side which symbolizes lust, knowledge, hope and anarchy. Appleââ¬â¢s most famous products include the iPad, the iPhone, the iPod, and the MacBook series of laptops. All products offered by Apple use the iOS operational system.On August 20th, 2012 the companyââ¬â¢s value broke the world record which is 624 billion dollars. iCloud is one of the companyââ¬â¢s flagship applications, which allows its users to store data on remote computer servers, so that they can synchronize that data with almost every device that has the iOS system. The iCloud system provides its users with the ability to upload everything from music to books, photos, apps, and et c. Every iCloud account offers 5gb of free storage space, additional space be purchased in 10, 20 or 50 GB.Other features that the application has are Find My Phone which allows users to track the location of their iOS device or Mac. Find My Friends is another feature which allows users to share their location. Back To My Mac is a service on the iCloud that allows users to login remotely to other computers configured with the same Apple ID. iTunes Match is newest feature of the storage app, customers can match and scan tracks from CDs or other sources and listen to the same tracks on iTunes free of charge. Cloudââ¬â¢s main competitors include Amazon Cloud Drive, Box. net, Dropbox, and Microsoft Skydrive. Amazon Cloud Drive is a storage system much like the iCloud, it was launched in March 2011 by Amazon. com, just like the iCloud it offers 5 GB of free storage, any additional storage can be purchased, the cost is 1$ per GB a year, which is a lot cheaper than the product that Appl e Inc. offers. Dropbox is a file hosting service operated by Dropbox Inc. which offers client software, file synchronization and cloud storage.Dropbox allows users to create a special folder on each personal computer that they have, which then Dropbox synchronizes so that the folder and its contents can be viewed on every PC or phone that it is synchronized with. Unlike Apple and Amazon, Dropbox only offers 2 GB of free space, while the paid Pro account offers up to 100 GB. Dropbox works with iOS, Android and Blackberry for mobile users and on Windows, Mac and Linux operating systems. Which is amazing because itis one of the few storage services that can be used on multiple software platforms. Box. net has been on the market since 2005 and has been a powerhouse in the segment.The personal edition of Box. net offers 5 GB of free space, while the maximum that can be purchased is 500 GB for 15 dollars a month with enhanced features. Box. net just like Dropbox works on multiple platform s. Microsoft Skydrive is Microsoftââ¬â¢s cloud storage system. The system offers 7 GB of free space, users that signed up prior to April 22nd received 25 GB of free storage enhancement. The service uses HTML5 technologies which allows customers to upload files of up to 300 MB in size by dragging and dropping the file into the web browser. Microsoft Skydrive works only for Windows Home and Windows Phone users.
Thursday, January 9, 2020
Child Centered Vs Standards Driven The Case For...
Child-centered versus Standards-driven: The Case for Constructivist Teaching Jacob Daniel EG 5023 July 24, 2014 Dr. Carrie Abood Child-centered versus Standards-driven: The Case for Constructivist Teaching The educational philosophy of teachers significantly impacts an educatorââ¬â¢s teaching style, and thus greatly impacts student learning. The philosophy of an educator affects the way they prepare for their classes, and essentially it aids in the formation of his or her teaching methodologies. In the United States, standards-driven learning has traditionally involved having students repeat newly presented information in reports or on tests. Child-centered teaching practices, in contrast, help students internalize, or transform, new information. If the goals of teaching school subjects are to be successfully accomplished, teachers of different subject areas should transform studentsââ¬â¢ engagement in subject matters from rote recall and comprehension to more meaningful analysis, synthesis, application, and evaluation via child-centered teaching models and methods. Child-centered teaching methods are p rimarily influenced by the philosophy of constructivism. Rooted in the field of cognitive science, constructivist pedagogy is especially informed by the ideas of John Dewey and William James; the later work of Jean Piaget; and the sociohistorical work of Lev Vygotsky and Jerome Bruner. Brooks and Brooks (1993) describe both the constructivist pedagogy and theShow MoreRelatedApplication of Observational Learning6241 Words à |à 25 PagesActivity and perception are prior to conceptualization. The teaching and learning situation is characterized as cognitive apprenticeship. From that follows that the activity of learning must take place in an authentic situation. Learning theories also can be prescriptive (tell how people should learn), but prescription is rather the role of pedagogical theory. DSchneider believes that it mostly a bad idea to blend learning and teaching theory. E.g. If one believes that knowledge is constructed oneRead MoreManagement Course: MbaâËâ10 General Man agement215330 Words à |à 862 PagesManaging Change 121 121 147 147 Text 3. Why Organizations Change Text Cohen â⬠¢ Effective Behavior in Organizations, Seventh Edition 14. Initiating Change 174 174 Text iii Cases 221 221 225 The Consolidated Life Case: Caught Between Corporate Cultures Whoââ¬â¢s in Charge? (The)(Jim)(Davis)(Case) MorinâËâJarrell â⬠¢ Driving Shareholder Value I. Valuation 229 229 253 279 1. The ValueâËâBased Management Framework: An Overview 2. Why Value Value? 4. The Value Manager Harvard BusinessRead MoreMetz Film Language a Semiotics of the Cinema PDF100902 Words à |à 316 Pagesedition of Christian Metz s Essais sur la signification au cinema, volume 1, was published by Editions Klincksieck in 1971, à © Editions Klincksieck, 1968. ÃËThe paper used in this publication meets the minimum requirements of the American National Standard for Information Sciences-Permanence of Paper for Printed Library Materials, ANSI Z39.48-1992. To George Blin, Profesor at the Collà ¨ge de France, whithout whom none of these pages would have been started. CONTENTS A Note on the Translation by
Wednesday, January 1, 2020
A Sociological Analysis of Ron Howards Apollo 13
Ron Howards re-creation of the happenings aboard NASAs Apollo 13 flight combined some of the biggest talent in Hollywood to produce a masterful film. Apollo 13 takes us back in time, to the late 1960s and early 70s, when Americas NASA space program was thriving and the world stood aside to see who would reach the moon first. The impacts of space program are still evident to this day. It is even said that by beating the Russians to the moon, we established ourselves are the top power in the world and propelled ourselves to the status we hold today. While today our space program flounders in the public eye, this movie illustrates a time when NASAs successes and failures held a huge sociological impact on American and evenâ⬠¦show more contentâ⬠¦Americans have now found more important things to worry about in their lives. Why risk lives in space when were already risking enough lives here in our country and overseas? The space program just cant hold its own anymore. The lo ss of lives and money in the Columbia and Challenger missions also plays as part of a power struggle in the government. Facing a growing debt and public criticism of NASAs failures, the government is forced to cut funding to our space program and subsequently, NASA begins to lose the struggle of power in the public eye. The space program in the 1960s promoted social solidarity in which it united the country in the race to be the first to the moon. America didnt want to lose out to the Russians and also feared Communist power had they made it to the moon before us. On the macro level, the space program of the 60s served as a driving force in the American-Russian rivalry. Each country continually upped the ante to see who was better, who could get to the moon first, and ultimately, who would prevail as the worlds top power. On the micro level, Jim Lovell and Fred Haise viewed the newcomer, Jack Swigert, as the outsider of their crew. They believed he truly didnt earn his spot with them and got there based on a faulty blood test. Days before the launch, Jim and Fred didnt like the new guy and had a small power struggle with him aboard the Apollo 13. However, once things went wrong and they put aside
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