Search results

  1. Y

    Peritoneum, abdominal walls (anterior/posterior )

    Keep in mind that all abdominal organs are covered with visceral peritoneum which is continuous with parietal peritoneum and is just given a different name because anatomists like to give new names to the same structure in different places. So if you were to use your suitcase analogy and...
  2. Y

    Chemical Safety - Storing Ammonium Nitrate

    Your first stop should be to look at the MSDS for storage of any chemicals. http://www.sciencelab.com/msds.php?msdsId=9927336
  3. Y

    Actin Treadmilling

    Going from memory here. Actin monomers and polymers are polar structures, meaning their structure shows unique characteristics at each 'end.' This polarity gives rise to the difference in polymerization and depolymerization kinetics at either end. Also, don't forget that actin monomers have a...
  4. Y

    News RIP Drakkith's PC

    That's because your PC wasn't all the way dead, it was only mostly dead.
  5. Y

    Today I learned

    This was yesterday, but it will have to do. Yesterday I learned that Fourier Transform Infrared (FTIR) spectroscopy was born from the Michelson interferometer used in the famous Michelson-Morley experiment.
  6. Y

    Gnuplot: reflexion of a graph in a quadrant to the other

    Just a guess as I haven't used gnuplot in a while, and haven't ever really used the splot stuff. Can you do something like, splot "data.dat" using 1:2:4 notitle, "data.dat" using ($1*-1):2:4, "data.dat" using 1:($2*-1):4, "data.dat" using ($1*-1):($2*-1):4
  7. Y

    Dangerous bacteria

    The idea in Ygggdrasil's post, although not explicit in the matter, covers the respiratory tract as well. As we are constantly breathing, all tissues and organs involved with respiration are interacting with the outside world constantly. It only makes sense that some bugs would find themselves a...
  8. Y

    Multi-centre trial = better than single-centre?

    I think Choppy is spot on here. I would be a bit surprised if you needed to cite research about designing a multi center study. It is more or less the statistics which favor such designs in order to recruit an appropriate amount of participants to increase statistical power...
  9. Y

    Laws of Thermodynamics

    In an idealized case where the walls of the container are rigid (so no work can be done) and perfect insulators, then the first law of thermodynamics tells us that the temperature would not change. Unfortunately, perfectly adiabatic systems do not exist as far as I know and are useful as...
  10. Y

    Biochemistry of Relaxing effect of Chamomile?

    I suggest you check out PubMed and/or PubMed Central and look for some reviews or relevant papers. The latter link will provide papers and reviews which are available to the public free of charge while the former will show papers which may or may not be behind pay walls. If you have access to...
  11. Y

    Voltaic (Daniell )cell

    Not trying to insult you, but your posts will be much easier to read if you refrain from posting one long sentence. I have two questions for you assuming I understood your post. 1. In your hypothetical metallic zinc bar + ZnCl2 setup, where would the electrons go? 2. If you are correct in...
  12. Y

    D and L Convention

    It is a rotation around the axis defined by the C4-C5 bond by 60°. Bonds are allowed to rotate, and do so very quickly without changing stereochemistry. Imagine the three substituents on C5 as the legs of a tripod, with the camera or whatnot as the rest of the molecule, and you may be able to...
  13. Y

    Alternate CPR technique

    I believe the OP meant the muscle pump. Although the wikipedia article seems to refer to some effects on arterial blood flow, it is more commonly thought that the muscle pump only aids in venous return via the little "check valves" that are found in our veins. Thus, it is unlikely that you can...
  14. Y

    Carbocations vs carbanions

    You are mixing up quite a few things here and it is very difficult to give you an answer. Let's clear up some terminology and ideas here. Carbonyl carbons do not form carbanions. In fact, carbonyl carbons have quite a bit of carbocation character, thus they are attacked by nucleophiles (think...
  15. Y

    Aldol Condensation

    That looks better. As far as your question goes, refer to the second part of my first post. Good and bad may be used as though they describe a binary phenomenon, but in reality things are not simply yes/no or good/bad. They all fall on a spectrum, so perhaps better terms would be better/worse...
  16. Y

    Beer's Law and Graph

    Hint: A = εbc ⇔ y = mx + b Hint 2: Because the b term (y-intercept) throws many off. What would the absorbance be if C = 0?
  17. Y

    Aldol Condensation

    The mechanism you drew is not correct in that the lone pair on the carbanion will not "kick off" the hydroxyl group as there is a methylene group between the two. Re-draw the mechanism from scratch to get a better idea of this reaction. As far as the hydroxyl leaving group, think about what is...
  18. Y

    Organic Addition Reactions

    I agree with your answer but I would advise you to learn the mechanism and work through it. Most importantly to learn what the key intermediate is and why a certain product may be formed instead of another. Your answer, I believe, is correct but the question is relatively straightforward...
  19. Y

    Can the heat of combustion only be found experimentally?

    Yes, heat of combustion is usually determined experimentally. It is a pretty trivial measurement by today's standards and very accessible. I think you may have it a little backwards. To determine the heat of formation of butane, you need to have graphite and hydrogen gas in their standard...
  20. Y

    Conversion of tertiary haloalkane

    A majority of introductory O-Chem is explained by charge/electron density as influenced by the Inductive Effect and Resonance Effects. Although I'm not exactly sure why radicals become more stable when they are "spread out," I have just come to accept this fact...
  21. Y

    Statistics Linearity Question

    R2 may be one way to do it but remember that is just a measure of how "far" away your linear fit is from the data (in the R2 it is squared to get rid of negative numbers and somehow normalized such that a perfect fit gets you a value of 1). You can have a lower R2 from noisy data which are still...
  22. Y

    Conversion of tertiary haloalkane

    Why would you assume that the rate of addition of bromine to the terminal carbons will be so high as to make free radical bromination not useful for this conversion? Think about the mechanism and selectivity of free radical bromination. What type of carbons are favored to form radicals in these...
  23. Y

    Organic Addition Reactions

    You need to show a bit more effort than just randomly guessing one of the choices. For the first one, can you talk about what type of reaction it is? What is the "key" intermediate which will determine the products? What factors affect the formation of the products from the "key" intermediate...
  24. Y

    Why are tetrasubstituted alkenes more stable than tri, bi, and mono-substituted alkenes?

    You are correct about about the cis- and trans-alkene case being readily explained by the increased steric strain for the cis-alkene case. When it comes to alkene stability in regard to substitution, the theory is meant to explain the trend that a more substituted alkene will have a smaller...
  25. Y

    Dumb Question: What Happens to Alcohol When it Evaporates?

    As was mentioned already, the alcohol doesn't disappear. It will diffuse away as a gas. Also, you will not evaporate ONLY the alcohol but a mixture of the alcohol and water which is enriched in alcohol due to the lower BP of the alcohol. At a certain point you will come to a mixture known as...
  26. Y

    Electron affinities

    I think you will find this website (http://chemwiki.ucdavis.edu/Physical_Chemistry/Physical_Properties_of_Matter/Atomic_and_Molecular_Properties/Electron_Affinity) discussed exactly the issue you are asking about.
  27. Y

    The Inductive Effect and Electronegativity

    Carboxylic acid acidity is better explained by resonance structures of the anion produced by deprotonation. The negative charge can resonate between both oxygens thus lowering the charge density and stabilizing the anion. I'm not sure if that is what the book explanation is trying to get at but...
  28. Y

    What is needed to read the DNA?

    Hunt around at www.ncbi.nlm.nih.gov Tons of databases there. There is a learning curve involved when trying to find and then analyze the data contained, but it isn't too difficult.
  29. Y

    Ideal solution

    What is the definition of an ideal solution?
  30. Y

    Wisdom Teeth Removal - Sedation Type

    Most miserable experience of my life. I had two impacted lower wisdom teeth done 1 week apart. About an hour after the surgery, when the local wore off and my pharmacy screwed up by NOT filling out my pain meds, I experienced the worst pain ever. I actually sobbed. Then a week of pain, swollen...
Top