degree of polymerization example
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Condensation polymers are any kind of polymers formed through a condensation reaction, releasing small molecules as by-products such as water or methanol, as opposed to addition polymers which involve the reaction of unsaturated monomers. Types of condensation polymers include polyamides, polyacetals and polyesters.
Condensation polymerization, a form of step-growth polymerization, is a process by which two molecules join together, resulting loss of small molecules which is often water. The type of end product resulting from a condensation polymerization is dependent on the number of functional end groups of the monomer which can react.
Monomers with only one reactive group terminate a growing chain, and thus give end products with a lower molecular weight. Linear polymers are created using monomers with two reactive end groups and monomers with more than two end groups give three dimensional polymers which are crosslinked.
Dehydration synthesis often involves joining monomers with an -OH (hydroxyl) group and a freely ionized -H on either end (such as a hydrogen from the -NH2 in nylon or proteins). Normally, two or more different monomers are used in the reaction. The bonds between the hydroxyl group, the hydrogen atom and their respective atoms break forming water from the hydroxyl and hydrogen, and the polymer.
Nylon is another common condensation polymer. It can be manufactured by reacting di-amines with carboxyl derivatives. In this example the derivative is a di-carboxylic acid, but di-acyl chlorides are also used. Another approach used is the reaction of di-functional monomers, with one amine and one carboxylic acid group on the same molecule:
The carboxylic acids and amines link to form peptide bonds, also known as amide groups. Proteins are condensation polymers made from amino acid monomers. Carbohydrates are also condensation polymers made from sugar monomers such as glucose and galactose.
Condensation polymerization is occasionally used to form simple hydrocarbons. This method, however, is expensive and inefficient, so the addition polymer of ethene (polyethylene) is generally used.
Condensation polymers, unlike addition polymers, may be biodegradable. The peptide or ester bonds between monomers can be hydrolysed by acid catalysts or bacterial enzymes breaking the polymer chain into smaller pieces.
The term online degrees refers to collegedegrees (sometimes including high school diplomas and non-degree certificate programs) that can be earned primarily or entirely through the use of an Internet-connected computer, rather than attending college in a traditional campus setting. Improvements in technology and the increasing use of the Internet worldwide have led to a proliferation of online colleges that award associateâ€™s, bachelorâ€™s, masterâ€™s and doctoral degrees.
The goal of educational accreditation, according to the U.S. Department of Education, is to ensure that programs provided by institutions of higher education meet acceptable levels of quality. In the area of online education, it is important to avoid diploma mills that offer fake degrees at a cost. Students seeking valid online degrees should obtain proof of accreditation from a regional or national/specialized accrediting body in the United States. Online colleges that are fully accredited have earned a widely recognized form of university accreditation from one of six regional accreditation boards.[http://www.ed.gov/admins/finaid/accred/accreditation_pg7.html]
Each of the six geographic regions of the United States has a non-governmental, regional agency that oversees and accredits degree-granting institutions headquartered in their areas. There are six regional accreditation boards:
- Middle States Association of Colleges and Schools
- Northwest Commission on Colleges and Universities
- North Central Association of Colleges and Schools
- New England Association of Schools and Colleges
- Southern Association of Colleges and Schools
- Western Association of Schools & Colleges
The Department of Education and the Council for Higher Education Accreditation (CHEA) recognize the Distance Education and Training Council (DETC) as the accrediting organization for distance learning institutions and education programs that offer online degrees.
Quality of Learning Online
Online education is a proven model for learning, with a lengthy track record. It enables accredited higher learning for individuals living with physical disabilities, busy working class people, soldiers and those living abroad, and stay at home parents to mention a few. There is fundamentally little difference between physically sitting in an auditorium listening to lectures versus watching a webcast video of the professor.
The recognition of the quality of online degrees compared to on-campus degrees varies. While most major online colleges are regionally accredited, the public perception of their quality is in dispute. Some experts argue that degrees in certain fields are more accepted online than in others, while some programs are less suited for online-only schools.
A survey by the Distance Education and Training Council found that 100 percent of employers who responded felt that distance education program graduates performed better on the job as a result of their degree (as compared to their previous performance). Additionally, employers felt that an employee receiving a distance education degree compared favorably, in terms of knowledge learned, to someone with a resident degree. On the other hand, The Chronicle of Higher Education reported in January 2007 on a Vault Inc. survey that found 55 percent of employers preferred traditional degrees over online ones. 41%, however, said they would give "equal consideration to both types of degrees."
The Sloan Consortium, an organization funded by the Alfred P. Sloan Foundation to maintain and improve the quality of distance education, publishes regular reports on the state of distance education in the U.S. In its 2006 report "Making the Grade: Online Education in the United States, 2006," it stated that "in 2003, 57 percent of academic leaders rated the learning outcomes in online education as the same or superior to those in face-to-face. That number is now 62 percent, a small but noteworthy increase."
In some instances, an online degree may be no different than a degree earned in a campus-based program. The instruction is often exactly the same, and the online degree contains no special designation. An example of this is the degree offered to Columbia University students who earn a degree through the Columbia Video Network (CVN) versus the campus-based program.
Prevalence of online education
The National Center for Education Statistics (NCES) conducted a distance education study based on the 2001-2002 academic year at 2-year and 4-year Title IV (Federal Student Aid)-eligible, degree-granting institutions. The study reported that 56 percent of all institutions surveyed offered distance education courses. The study also found that public institutions were more likely to offer distance education than were private institutions.
The Sloan Consortium, based on data collected from over 2,200 colleges and universities, reports that nearly 3.2 million students took at least one online course during 2005 (a significant increase over the 2.3 million reported in 2004). According to the same report, about two-thirds of the largest institutions have fully online programs.
Until recently, students enrolled in online degree programs were not eligible for federal student aid unless at least half of their program was campus based (a law established in 1992 and k
Scales of temperature measured in degrees
Common scales of temperature measured in degrees:
- Celsius (Â°C)
- Kelvin (K), which uses the Celsius scale, adjusted so that 0 kelvins is equal to absolute zero.
- Fahrenheit (Â°F)
- Rankine (Â°R or Â°Ra), which uses the Fahrenheit scale, adjusted so that 0 degrees Rankine is equal to absolute zero.
Other scales of temperature:
The degree Kelvin (Â°K) is a former name for the SI unit of temperature on the thermodynamic (absolute) temperature scale. Since 1967 it has been known simply as the kelvin, with symbol K. Degree absolute (Â°A) is obsolete terminology, often referring specifically to the kelvin but sometimes the degree Rankine as well.
- Boiling point of water: 100.0 Â°C / 212.0 Â°F
- Melting point of ice: 0.0 Â°C / 32.0 Â°F
- Typical human body temperature: 37.0 Â°C / 98.6 Â°F
- Room temperature: 20 - 25 Â°C / 68 - 77 Â°F
A master's degree is an academic degree granted to individuals who have undergone study demonstrating a mastery or high-order overview of a specific field of study or area of professional practice. Within the area studied, graduates are posited to possess advanced knowledge of a specialized body of theoretical and applied topics; high order skills in analysis, critical evaluation and/or professional application; and the ability to solve complex problems and think rigorously and independently.
In some languages, a master's degree is called a magister, and magister or acognate can also be used for a person who has the degree. There are various degrees of the same level, such as engineer's degrees, which have different names for historical reasons. See List of master's degrees.
There has recently been an increase in programs leading to these degrees in the United States; more than twice as many such degrees are now awarded as compared to the 1970s. In Europe, there has been a standardisation of conditions to deliver the master's degrees and most countries present degrees in all disciplines.
The two most common titles of master's degrees are the Master of Arts (M.A.) and Master of Science (M.S. or M.Sc.); these may be course-based, research-based, or a mixture of the two. Some universities use the Latin degree names; because of the flexibility of word order in Latin, the Master of Arts and Master of Science may be known as magister artium or artium magister and magister scientiÃ¦ or scientiarum magister, respectively. Harvard University and MIT, for example, use A.M. and S.M. for their master's degrees. More commonly, Master of Science often is abbreviated MS or M.S. in the United States, and MSc or M.Sc. in Commonwealth nations and Europe.
Other master's degrees are more specifically named and include the Master of Music (M.M. or M.Mus.), Master of Communication (M.C.), Master of Physician Assistant Studies (M.P.A.S.) and the Master of Fine Arts (M.F.A.); some are similarly general, for example the M.Phil. and the Master of Studies. See List of master's degrees.
Full time post-graduate master's degree (MA, MS, MBA, and other subject specific master's degrees) is designed for anyone who holds a bachelor's degree.
Executive master's degree (EMBA, EMS) is an advanced level of master's degree designed specially for executive professionals. Admission, graduation requirements, and structure of executive master's degrees differ from that of the regular full-time program.
There are a range of pathways to the degree, with entry based on evidence of a capacity to undertake higher degree studies in the proposed field. A dissertation may or may not be required, depending on the program.
The master's is usually offered at a postgraduate level, although it is also offered as an undergraduate degree. Some university programmes provide for a joint bachelor's and master's degree after four or five years.
In the recently standardized European System of higher education (Bologna process), a master's degree corresponds to 60 - 120 ECTS credits (one- or two-year full time postgraduate program) undertaken after at least three years of undergraduate studies. It provides higher qualification for employment or prepares for doctoral studies. In general, though, the structure and duration of a program of study leading to a master's degree will differ by country and by university:
- In some systems, such as those of the USA and Japan, a master's degree is a postgraduateacademic degree awarded after the completion of an academic program of one to six years in duration.
- In the systems of a limited number of countries, such as England, Scotland (students entering their education after July 2007), and Ireland, a master's degree can be both an undergraduateacademic degree awarded after the completion of an academic program of four (or sometimes five) years, or a postgraduateacademic degree awarded after the completion of an academic program of one to two years.
In countries in which a master's degree is a postgraduate<
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Answers:A natural polymerization: how about natural rubber trees (Hevea Brasiliensis), or even gutta percha. Others are: Glycogen formation is done by polymerizing glucose. Protein formation is a polymerization of amino acids (a natural copolymer, or heteropolymer) Synthesizing DNA is a natural polymerization, where nucleotides are the "mers." Hope that helps ya out.
Answers:You add a chain terminator to the original polymerization mixture. For example, suppose that a polymer chain is growing through free radical polymerization. You add something like CCl4. The -CH2CH2* abstracts Cl from CCl4 and ends in -CH2CH2Cl.
Answers:Addition polymerisation is the process of attaching monomers together in order to form large chain polymers. The monomer MUST have a double bond in order to polymerise. Examples of this are formation of certain plastics formed from small alkenes: polyethene from ethene Cracking is the reverse, so it is the process of taking a large polymer and then breaking it down into smaller molecules which have more uses. This is usually done with a ceramic catalyst and heat. i.e. octane is broken down to ethene and hexane.
Answers:in addition polymerization as accompanied by the removal of a hydrogen and a hydroxyl group from two adjacent molecules. this results in dehydration as the H and OH join to form water.for example you may consider the peptide linkage.