Nuclear power is being used increasingly, particularly in Europe and North America. One argument in favour of its use is that it does not produce greenhouse gases, unlike power stations which burn fossil fuels. So is nuclear power 'clean'?
Of course, not. To appreciate the problems, we need to think about the complete fuel cycle, starting with mining. Uranium ore contains only a small percentage of uranium, and extracting it produces large volumes of radioactive waste. The uranium is then usually enriched to increase the proportion of U relative to ' U. More waste results.
Once the fuel rods are spent, they must be removed from the core and replaced. The old rods are highly radioactive, and must be cooled in large tanks of water for several months before they can be taken away and stored. Sometimes the spent fuel is reprocessed; this is what happens at Sellafield in Cumbria. The idea is to extract any remaining U and re-use it; plutonium is also separated for use in reactors or bombs. The most hazardous waste products are concentrated with the intention of storing them safely. However, no-one is sure how to do this in the best possible way. The problem will be around for thousands of years because of the long half-lives of the substances involved.
At the end of its life a power station must be decommissioned. It is dismantled, and the most radioactive parts are taken away for safe storage. The site is eventually levelled and is unlikely to be fit for other uses for several decades.
In practice, nuclear power stations have proved relatively safe. There have been some spectacular accidents — notably the fire at Chernobyl in the Ukraine in 1986 which resulted in thousands of deaths and illnesses. The UK's nuclear stations have been carefully operated, but many are now reaching the ends of their lives. Should they be replaced?
In fact, there is a glut of electricity, and prices have fallen. Most new power stations use natural gas as a fossil fuel, and nuclear power cannot produce electricity as cheaply as these. Are we being shortsighted burning gas which is a non-renewable resource and which contributes to climate change?
1. An abstract is a condensed version of a longer piece of writing that highlights the major points covered, concisely describes the contents and scope of the writing, and reviews the contents of the writing in abbreviated form.
2. An abstract is a succinct summary of a longer piece of work, usually academic in nature, which is published in isolation from the main text and should therefore stand on its own and be understandable without reference to the longer piece. It should report the essential facts of the latter and should not exaggerate or contain material that is not there.
Writing in chemistry is similar to writing in other disciplines in that your paper must have a clear purpose that explains why you are writing, a thesis statement or main idea that defines the problem to be addressed, and background information wherever necessary. In addition, you should include evidence in the form of figures, graphs, and tables to support your argument. Ideally, the abstract can be thought of as one or two sentences from each section of the paper that form a cohesive paragraph that summarizes the entire paper. The abstract should be single spaced unless you receive other instructions from your professor.
When writing an abstract, you should avoid too much experimental detail (e.g. concentration of stock solutions used) or preliminary results (i.e. "raw" data). In addition, make certain that the purpose of the experiment is stated clearly and early in the abstract. Ideally, it should be stated in the first or second sentence.
Its purpose is to act as a reference tool (for example in a library abstracting service), enabling the reader to decide whether or not to read the full text.
Two common reasons for writing an abstract are
- to summarize a longer piece of work published as a journal article, thesis, book or web page, an existing article for the purposes of a journal,
- to submit an application to write a paper for a conference.
II. Qualities of a Good Abstract
An effective abstract has the following qualities:
uses one or more well developed paragraphs: these are unified, coherent, concise, and able to stand alone.
uses an introduction/body/conclusion structure which presents the article, paper, or purpose, results, conclusions, and recommendations in that order.
follows strictly the chronology of the article, paper, or report.
provides logical connections (or transitions) between the information included.
adds no new information, but simply summarizes the report.
is understandable to a wide audience.
often uses passive verbs to downplay the author and emphasize the information. Check with your teacher if you're unsure whether or not to use passive voice.
III. Two types of abstracts are typically used:
1. Descriptive Abstracts
· tell readers what information the report, article, or paper contains.
· include the purpose, methods, and the scope of the report, article, or paper.
· do not provide results, conclusions, or recommendations.
· are always very short, usually under 100 words.
· introduce the subject to readers, who must then read the report, article, or paper to find out the author's results, conclusions, or recommendations.
Proceed in the following way:
- Make a list of all the topics covered in the research paper that need to be talked about.
- Descriptive abstracts are short! No more than 100 words.
- Simply introduce the subject to the reader.
- Revise your abstract a few times to make sure it is clear and concise and that it reads in the same voice as the paper.
2. Informative Abstracts
· communicate specific information from the report, article, or paper.
· include the purpose, methods, and scope of the report, article, or paper.
· provide the report, article, or results of the paper, and conclusions.
· are short - from a paragraph to a page or two, depending upon the length of the original work being abstracted. Usually informative abstracts are 10% or less of the length of the original piece (from 150 to a maximum of 200 words).
· allow readers to decide whether they want to read the report, article, or paper.
Proceed in the following way:
- Summarize your paper. The summary should be thorough, but brief.
- Start by making a list of all the information the reader should know just by reading the abstract.
- Tell why someone should care about your research. What you were trying to find and why it matters is a good place to start. What hole is your research filling?
- Explain the nature of the work performed, especially if it was a scientific experiment. The details of your apparatus, materials, or experiment may go in your main paper, but explain enough of the basics that someone would need to know to understand what you have done.
- Outline any hypotheses or theories advanced in the paper.
- Leave out any tables, complicated explanations, etc. The reader can find those in the paper.
- Include the findings, results, or conclusions of your paper. This is not a murder mystery, so there is no need to reserve the conclusions for the end.
- What are the larger implications of your findings?
- Proofread your abstract and have somebody else proofread it for you. Does it make sense? Is everything clearly stated? Is it thorough but concise? Is it in an appropriate style?
IV. Structure of a Typical Abstract
Almost all scientists agree that an informative abstract should have the following five parts:
Introduction. This is where you describe the purpose for writing your paper or doing research. The abstract begins by stating the main objective of the experiment/report in one or two sentences. Why should anyone care about the work you did? You have to tell them why. If you made an invention or developed a new procedure how is it better, faster, or cheaper than what is already out there? Motivate the reader to finish the abstract and read the entire paper.
Problem Statement. Identify the problem you solved or the hypothesis you investigated.
Procedures. The name of the methods used to complete the work is cited. Specifics about the materials used or set-up details are not included in the abstract. In most cases, one to three sentences should be sufficient for describing the methods. What was your approach for investigating the problem? Don't go into detail about materials unless they were critical to your success. Do describe the most important variables if you have room.
Results. The experimental findings are reported next, in the most concise and direct manner possible. The length of this section of the abstract varies depending on the nature of the experiment. What answer did you obtain? Be specific and use numbers to describe your results. Do not use vague terms like "most" or "some."
Conclusions. The conclusion section is a concise analysis and interpretation of the results of the work. This section should make an impact on the reader so that it is clear what the outcome of the scientific work is and what it means. State what your science project or invention contributes to the area you worked in. Did you meet your objectives?
· Using keywords. Using keywords is a vital part of abstract writing, because of the practice of retrieving information electronically: keywords act as the search term. Use keywords that are specific, and that reflect what is essential about the paper. Put yourself in the position of someone researching in your field: what would you look for? Consider also whether you can use any of the current "buzz words".
V. Things to Avoid
Avoid jargon or any technical terms that most readers won't understand.
Avoid abbreviations or acronyms that are not commonly understood unless you describe what they mean.
Abstracts do not have a bibliography or citations.
Abstracts do not contain tables or graphs.
For most science projects, the abstract must focus on the latest research, and give only minimal reference to any earlier work.
If you are working with a scientist or mentor, your abstract should only include procedures done by you, and you should not put acknowledgements to anyone in your abstract.
How to Meet the Word Limit
Most authors agree that it is harder to write a short description of something than a long one. Here's a tip: for your first draft, don't be overly concerned about the length. Just make sure you include all the key information. Then take your draft and start crossing our words, phrases, and sentences that are less important than others. Look for places where you can combine sentences in ways that shorten the total length. Put it aside for a while, then come back and re-read your draft. With a fresh eye, you'll probably find new places to cut. Before you know it you will have a tightly written abstract.
VI. Sample Abstracts
Conversion Of Optically Active Acid-Esters To Ester-Acid Chlorides Without Loss Of Optical Activity Sean Purdy (Senior, Chemistry), Mason Marsh (Senior, Chemistry) Stephen Flowers (Junior, Biology), Brenda Benfield (Junior, Biology) Advisor: Dr. George B. Trimitsis, Chemistry
It has been reported in the literature that attempts to convert optically active acid-esters to their corresponding ester-acid chlorides by standard procedures is often accompanied by loss of optical activity. The purpose of the present investigation was to develop a suitable experimental procedure for the conversion of methyl (R)-3-methyl glutarate (1) to the corresponding ester-acid 2 with preservation of optical purity. A number of suitable reagents and reaction conditions for accomplishing this goal will be discussed. The present investigation also sought to develop an accurate and convenient assay for determining the enantiomeric excess of compounds 1 and 2. Although 1NMR can be used for this purpose, it was found that GC-MS offers a number of distinct advantages. A comparison of the two analytical procedures will be presented.
Using Melting Point to Determine the Identity of an Unknown Organic Acid
Martha A. Hass Albany College of Pharmacy, Organic Chemistry Lab Tuesday Morning Section June 15, 2002
The identity of an unknown organic acid was determined. The compound was taken from a list of twenty, known organic acids, each with different melting points. An experimental melting point was determined for the unknown compound using a Fisher-Johns melting point apparatus. The thermometer of the apparatus was calibrated using benzoic acid as a standard. An experimental melting point (calibrated) of 184°C for the unknown acid was measured. This value most closely correlated with the literature melting point of p-anisic acid, one of the possible twenty compounds on the list. None of the other compounds on the list had melting points within 5°C of the experimental melting point. The unknown was identified as p-anisic acid. Experimental determination of the melting point of an unknown compound is useful for identifying the compound.
Rapid methods to detect organic mercury and total selenium in biological samples
Dong-Ha Nam and Niladri Basu* Chemistry Central Journal 2011, 5:3 doi:10.1186/1752-153X-5-3 13 January 2011
Organic mercury (Hg) is a global pollutant of concern and selenium is believed to afford protection against mercury risk though few approaches exist to rapidly assess both chemicals in biological samples. Here, micro-scale and rapid methods to detect organic mercury (< 1.5 ml total sample volume, < 1.5 hour) and total selenium (Se; < 3.0 ml total volume, < 3 hour) from a range of biological samples (10-50 mg) are described.
For organic Hg, samples are digested using Tris-HCl buffer (with sequential additions of protease, NaOH, cysteine, CuSO4, acidic NaBr) followed by extraction with toluene and Na2S2O3. The final product is analyzed via commercially available direct/total mercury analyzers. For Se, a fluorometric assay has been developed for microplate readers that involves digestion (HNO3-HClO4 and HCl), conjugation (2,3-diaminonaphthalene), and cyclohexane extraction. Recovery of organic Hg (86-107%) and Se (85-121%) were determined through use of Standard Reference Materials and lemon shark kidney tissues.
The approaches outlined provide an easy, rapid, reproducible, and cost-effective platform for monitoring organic Hg and total Se in biological samples. Owing to the importance of organic Hg and Se in the pathophysiology of Hg, integration of such methods into established research monitoring efforts (that largely focus on screening total Hg only) will help increase understanding of Hg's true risks.
Tasks and Activities
Assignment I. To make sure your abstract meets the requirements and you have not forgotten or left out anything it is recommended to apply the checklist provided below. If everything is OK you should answer ‘Yes’ to every question. If any question gets a ‘No’ answer, you should carefully study the failure and improve your piece of writing. Apply this to one of the sample abstracts.
What Makes for a Good Abstract on a Science Project?
You Should Answer ‘Yes’/’No’ to Every Question
Does your science abstract include:
Yes / No
Yes / No
Yes / No
Yes / No
Did you review the list of "Things to Avoid" in a science fair project abstract?
Yes / No
Did you write the abstract so that the reader is motivated to learn more about your science project and its results?
Yes / No
Assignment II. You have a number of words and word collocations which belong to different parts of the abstract structure. Analyze which part they belong to and classify them according to the correct categories in the table below. Can you add some more words?
It is necessary that a more thorough study of the phenomenon should be done.., The primary aim of the study is to test ..., Particular attention is given to the optimal operating conditions…, The results obtained for both ketones studied are found to be very valuable for further research…, The problem was studied (a study was made of...)…, The process involved heating and was followed by quick cooling…, Finally the substance is washed, dried and weighed…, The object of the experiment is to describe ..., The paper studies some photochemical characteristics of the substances concerned…, The chief purpose of the investigation is to establish ..., The remarkable characteristic of the resulting compound is its resistance to aging and specific electrical insulating properties…, The conclusion is made that these mixtures have several advantages over others…
Assignment III. Apply the knowledge you have just acquired to a particular piece of writing:
1. Find three or four written abstracts from some papers you have read as part of your home reading assignment. It is important that you have actually read most of the papers.
2. Diagram each abstract into the 5 parts above.
3. Discuss with your group mates how each abstract meets or does not meet the above criteria. Some good abstracts may not perfectly match the criteria.
4. Discuss how they could be improved or why their choice is appropriate to the work and/or results in this paper.
5. Choose an abstract to improve and work on a computer or on paper to rewrite it. You can insert specifics that make the abstract correct, engaging and exclusive!
Assignment IV. Write an abstract for your project (e.g., your current or previous term paper), regardless of the status of the project. You should diagram the abstract and present it in class.
Even if the project is only half way through, you can write an optimistic abstract in which all the experiments or proofs turn out perfectly. Ask your scientific supervisor or the teacher in charge of the course to help you identify what the problem is and why it is important.