specific gravity density and the baricity paradox

0At 37 C water has a specific gravity of 0.9937  , and a density of 993.37 Kg/ m3

% concentration in medicine is usually weight by volume

0.9% Saline means 9mg of NaCl in 1ml of saline or 9g in 1L of saline or 9000g or 9kg in 1m3

So 1009 kg/m3 if it is made at 4 C. 

Assuming it is made at 37 C  993.37+9 Kg  Density is 1002.37 Kg/m3  Specific gravity is 1.00237

1mg/ml = 1kg/m3

Specific Gravity (SG) of CSF varies from 1.0063 to 1.0075 at 37 C 1 (~1.007)

This means the ~1007kg is present in 1 m3

Another real world example is of Sea Water.

As temperature increases, density decreases. As salinity of the water increasaes, density also increases. Although the density of seawater varies at different points in the ocean, a good estimate of its density at the ocean’s surface is 1025 kilogram per cubic meter. Its specific gravity is therefore 1.025 or 1.025g/ml

Bupivicaine hydrochloride  C18H29ClN2O  Molecular Weight is 324.893 g/mol Which is totally not needed as we are talking about mg in % and not exactly moles while calculating the weight in the solution which is needed to calculate the density and the specific gravity respectively.

So 0.5% Bupivicaine means 0.5 kg in 1m3 and 8.25% dextrose means 8.25kg of dextrose in 1 m3  Total mass is hence 8.75Kg in 1m3 . Supposing this was made at 37 C  993.37 Kg/m3  + 8.75 Kg/m3

 

So the density of the above is 1002.12 Kg/m3  and the specific gravity is 1.0021 .

Now the specific gravity of CSF is  1.007 which makes the solution isobaric and totally wrong.

The Density on the other hand is 1.00065g/ml or 1000.65kg/m3  which is less than hyperbaric bupivacaine at 1002.12Kg/m3.

In 1964 the definition of litre was changed to 1/1000 of 1m3 f water
Density is mass by volume

At 37 C At the density of CSF is ~1.00065 g/ml or 1000.65kg/m3

At 37 C In pregnancy it is usually 1.00033 g/ml or 1000.33kg/m3

At 37 C waters density is 0.99337g/ml or 993.7 kg/m3

The solution is hyperbaric if its density exceeds 1.00099, (1001kg/m3)

hypobaric when its density is lower than 1.00019, (1000.2 Kg/m3)

and isobaric when its density is greater than 1.00019 and lower than 1.00099. 2
Specific gravity and density and a logarithmical paradox

Density = Mass / Volume. Specific gravity is the density of a substance divided by the density of water. Since (at standard temperature and pressure) water has a density of 1 gram/cm3, and since all of the units cancel, specific gravity is usually very close to the same value as density (but without any units). 

Need the following articles

1. Density, specific gravity, and baricity of spinal anesthetic solutions at body temperature. Anesthesia and Analgesia. 76(5):1015-8, MAY 1993 T T Horlocker; D J Wedel

References

1. Anesth Analg. 1981 Nov;60(11):814-7. Density of normal human cerebrospinal fluid and tetracaine solutions. Levin E, Muravchick S, Gold MI. 

2. Assessment of the Densities of Local Anesthetics and Their Combination with Adjuvants. An Experimental Study Luiz Eduardo Imbelloni, TSA1, Adriano Dias Moreira2, Flávia Cunha Gaspar3 , Marildo A. Gouveia, TSA4, José Antônio Cordeiro5. Rev Bras Anestesiol 2009; 59: 2: 154-165

3. Density of lumbar cerebrospinal fluid in pregnant and nonpregnant humans. Richardson MG1, Wissler RN. Anesthesiology. 1996 Aug;85(2):326-30.

Advertisements

Three Golden Locks

Feanor was greatest among the elves. The first born of the first elf created by Iluvatar he was unparalleled in skill of hand and his craft was the admiration of the Valar.  Strong willed in both good and evil, proud in despair his oath his doom. Galadriel was born of his step mother’s son.  Galadriel, most beautiful of all of  the  house of  Finwë (Feanor’s step brother ) her  hair  was  lit  with  gold  as  though  it  had  caught in  a  mesh the  radiance  of  Laurelin.  They all lived more or less as kin, but Feanor was considered eldest and heir. Galadriel was the greatest of the noldor, save Feanor maybe, though she was wiser than he and her wisdom grew with her age. The Eldar said, perhaps the light of the two trees were snared in her tresses. Feanor beheld the hair of Galadriel with wonder and  delight and THRICE begged for a tress. But Galadriel could look into hearts even in her youth , and she saw darkness and greed in Feanor’s and did not give a single lock. And the two greatest of the elves were unfriends forever. Feanor however having got the idea about the mingling of the lights off the two trees from Galadriel’s hair he creates the greatest jewels on Ea and captured the light of the two trees – the three silmarilli. Many ages pass. The treachery of Morgoth and  his ultimate end, the many sorrows of the elves, the waxing and waning of Numenor and the power of Sauron and under the twilight of the  age of the Rings, during the farewell to Lörien the epic conversation between dwarf and elf occurs. Dwarves were  created by Aüle and adopted by Iluvatar but were put in hibernation to wake up later, so that the children of Iluvatar’s design, the firstborn, the elves come  in the big picture in the beginning. They were to forever dislike each other.
So when Gimli son of Gloin stutters and stammers into one of the most thought provoking scenes in LOTR. . 
‘None, Lady,’ answered Gimli. ‘It is enough for me to have seen the Lady of the Galadhrim, and to have heard her gentle words.’ ‘Hear all ye Elves!’ she cried to those about her. ‘Let none say again that Dwarves are grasping and ungracious! Yet surely, Gimli son of Glóin, you desire something that I could give? Name it, I bid you! You shall not be the only guest without a gift.’ ‘There is nothing, Lady Galadriel,’ said Gimli, bowing low and stammering. ‘Nothing, unless it might be –unless it is permitted to ask, nay, to name a single strand of your hair, which surpasses the gold of the earth as the stars surpass the gems of the mine. I do not ask for such a gift. But you commanded me to name my desire.’ The Elves stirred and murmured with astonishment, and Celeborn gazed at the Dwarf in wonder, but the Lady smiled. ‘It is said that the skill of the Dwarves is in their hands rather than in their tongues,’ she said; ‘yet that is not true of Gimli. For none have ever made to me a request so bold and yet so courteous. And how shall I refuse, since I commanded him to speak? But tell me, what would you do with such a gift?’ ‘Treasure it, Lady,’ he answered, ‘in memory of your words to me at our first meeting. And if ever I return to the smithies of my home, it shall be set in imperishable crystal to be an heirloom of my house, and a pledge of good will between the Mountain and the Wood until the end of days.’ Then the Lady unbraided one of her long tresses, and cut off THREE golden hairs, and laid them in Gimli’s hand. ‘These words shall go with the gift,’ she said. ‘I do not foretell, for all foretelling is now vain: on the one hand lies darkness, and on the other only hope. But if hope should not fail, then I say to you, Gimli son of Glòin, that your hands shall flow with gold, and yet over you gold shall have no dominion.
Feanor in his pride bound his and his children’s  destiny to the crowning glory of his creation the silmarilli. Long ages of war with the shadow and destruction of anything in their path with little regard to kin passed away when the silmarilli was finally in their hands when they realised that they could not hold the gems. The destruction, sorrow and hate they had left in their wake had changed them. But rather than let go, they chose destruction and perished with their prize.

image

When Galadriel says that gold would have no dominion over Gimli we see the diametric opposite of Feanor whose greed and pride blinded and mastered him even to his fall.
Gimli wanted to treasure the locks like the Silmarilli in unperishable crystal but not out of pride and greed but out of love and friendship, to remember and cherish and grow. Though it seems the same, yet everything was different. The fate of children of design and of hopeful chance meeting their destiny in a friendship till time endured.

The Good Samaritan

The greatest industry in the world is science. Throughout history scientific research  has consistently discovered more  new and strange  questions to which answers must be found than finding out actual answers in itself. It is  the  perfect industry. Because being as curious as we are we  would keep working & spending as much as we  can  and sometimes beyond to find answers that  matter. Self propogation to the utmost. You will never run out of jobs as scientists. There will always be something better than before to discover. Science almost has a life of its own.  Continuously evolving and changing and only shaped by our understanding of it.
The strange thing is, at  every age of discovery we come to the weird conclusion that we have discovered everything of substance and that there is nothing more to discover. And that’s when we get mind blown by something so totally radical and new. From time immemorial the  geocentric theory, splitting of the atom, relativity, quantum physics have all shown the same. And now we  are stuck in an abyss of non knowledge into which  we happily dive with dark matter and energy and probably many other things to find the perfect pearl of wisdom. On  a more random thought, the religion I follow has an interesting and important phrase. It  kind of paraphrases humanity’ ideal like an emeralds tablet did for the alchemists.  LOVE GOD.  Your God maybe science, Jesus , Krishna, Allah or Alchemy. The name probably don’t matter.
The second and  more importantly today, LOVE YOUR NEIGHBOUR. Now who is your neighbor. Not  a better story exists than the story of the good samaritan. I hope terrorism is erased. But hopes are not reality and we fight daily for a better peaceful future.  Exciting times ahead as ever.

Social Networking gave me a job

Disconnecting people seems to be a worrisome word compared to the well known logo of  NOKIA. If  the nightmare  were to come true, that’s what I would  do.
In the  occasional meme that we  come  across we  see a future family, where  the  mom threatens to  destroy her kids’ online  universe if she  doesn’t do her homework first.. A ideal future with  strong social  links founded on  a virtual universe. Everyone is  online that it’s not  such  a big deal  and  hopefully everyone is sane enough to  have  a bit  of an  exercise and experience other ways to  have  fun than just a  stark virtual reality.
But what if  that doesn’t happen. We  on  the  other hand are  dealt  a bunch of  adults hooked to  an  online world neglecting social and  financial responsibility. It may  happen. It  maybe happening. There are many unhappy stories of spouses leaving because of the strains of  such  relationships. Using social networks in  a healthy balance could  be  a key, but such  a balance is not  inborn, and  neither is it taught. Especially as the online world becomes increasingly real, the damage caused to  society is subtle, thanks to the inability to  differentiate.
So now coming to new job opportunities in such dysfunctional societies. Apart from the obvious group therapies & activities I’m  envisioning a burgeoning industry in looking after kids.  Not tiny little ones. But in the toddler to young adult stage. But isn’t this concept already existent. Well you just need to  brand it, label it anew and sell it ( in the  social media).
Hopefully it won’t be  just that ridiculous. Every generation and young people grow up in  a different environment. It  would be  interesting to  see how  a school could be  built around these concepts. Weird social issues as and when they crop up can be solved by a different sets of means than the traditional carrot or stick.
Well I’m still thinking. Let’s see how things go