Conway base 13 function: Difference between revisions

From formulasearchengine
Jump to navigation Jump to search
en>AnomieBOT
m Dating maintenance tags: {{Fact}} {{Refimprove}} {{No footnotes}}
 
en>David Eppstein
→‎Properties: copyedit to avoid first person and colloquialisms
Line 1: Line 1:
Hi there. My name is Garland even though it is not the name on my beginning certification. Her family members life in Idaho. After being out of my job for years I grew to become a manufacturing and distribution officer but I strategy on changing it. Playing crochet is a thing that I'm totally addicted to.<br><br>Review my web site: [http://checkmates.co.za/index.php?do=/profile-1592/info/ http://checkmates.co.za/]
'''Johannes Martin Bijvoet''' [[ForMemRS]]<ref name="frs">{{cite doi|10.1098/rsbm.1983.0002}}</ref> (23 January 1892, [[Amsterdam]] – 4 March 1980, [[Winterswijk]]) was a Dutch [[chemist]] and [[crystallography|crystallographer]] at the van 't Hoff Laboratory at [[Utrecht University]]. He is famous for devising a method of establishing the [[absolute configuration]] of [[molecules]].<ref>{{cite doi|10.1038/134849a0}}</ref><ref>{{cite doi|10.1038/162771a0}}</ref><ref>{{cite doi|10.1038/168271a0}}</ref><ref>{{cite doi|10.1038/169949a0}}</ref><ref>{{cite doi|10.1038/173888a0}}</ref><ref>Bijvoet, J. M. ''Proc. Acad. Sci. Amst.'' '''52''', ''1949'', 313.</ref><ref>Peerdeman, A. F., van Bommel, A. J., Bijvoet, J. M. ''Proc. Acad. Sci. Amst.'' '''54''', ''1951'', 16.</ref>
 
The concept of [[tetrahedron|tetrahedrally]] bound [[carbon]] in [[organic compound]]s stems back to the work by [[Jacobus Henricus van 't Hoff|van 't Hoff]] and [[Joseph Achille Le Bel|Le Bel]] in 1874. At this time, it was impossible to assign the absolute configuration of a molecule by means other than referring to the projection formula established by [[Hermann Emil Fischer|Fischer]], who had used [[glyceraldehyde]] as the prototype and assigned randomly its absolute configuration.
 
In 1949 Bijvoet outlined his principle, which relies on the [[anomalous dispersion]] of [[X-ray]] [[electromagnetic radiation|radiation]]. Instead of the normally observed [[elastic scattering]] of X-rays when they hit an [[atom]], which generates a scattered wave of the same energy but with a shift in phase, X-ray radiation near the [[absorption (electromagnetic radiation)|absorption]] edge of an atom creates a partial [[ionisation]] process. Some new X-ray radiation is generated from the inner [[electron shell]]s of the atoms. The X-ray radiation already being scattered is interfered with by the new radiation, both [[amplitude]] and [[phase (waves)|phase]] being altered. These additional contributions to the scattering may be written as a real part <math>\Delta</math>''f''' and an imaginary one, <math>\Delta</math>''f''". Whereas the real part is either positive or negative, the imaginary is always positive, resulting in an addition to the [[phase angle]].
 
In 1951, using an X-ray tube with a [[zirconium]] target, Bijvoet and his coworkers Peerdeman and van Bommel achieved the first experimental determination of the absolute configuration of sodium rubidium [[tartrate]]. In this compound, [[rubidium]] atoms were the ones close to the absorption edge. In their later publication in [[Nature (journal)|''Nature'']], entitled ''Determination of the absolute configuration of optically active compounds by means of X-rays'', the authors conclude that
 
"The result is that Emil Fisher's ''convention'', which assigned the configuration of FIG. 2 to the dextrorotatory acid ''appears to answer the reality''."
 
The determination of absolute configuration is nowadays achieved using "soft" X-ray radiation, most often generated with a [[copper]] target (which generates X-rays with a characteristic wavelength of 154 pm). Shorter wavelengths make the observable differences in measured intensities smaller, thereby making the distinction of absolute configuration more difficult. The measurement of absolute configuration is also facilitated by the presence of atoms heavier than oxygen.
 
X-ray diffraction is still considered the ultimate proof of absolute structure, but other techniques such as [[circular dichroism]] spectroscopy are often used as faster alternatives.
 
==Bijvoet Center==
{{main|Bijvoet Center for Biomolecular Research}}
The Bijvoet Center for Biomolecular Research at Utrecht University, which was founded in 1988, was named after him.<ref name="CC_Apr_1988">{{Cite news
|title=SON en RUU in Bijvoet Centrum
|author=Joop Kessels
|newspaper=Chemische Courant
|date=April 7, 1988
|language=Dutch
}}</ref> The Bijvoet Center performs research on the relation between the structure and function of biomolecules, including [[proteins]] and [[lipids]], which play a role in biological processes such as regulation, interaction and recognition.<ref name="DUB_1">{{Cite news
|title=Bijvoet Centrum (1): ziektes bestrijden op atomair niveau
|newspaper=DUB
|author=Erik Hardeman
|date=October 30, 2012
|language=Dutch
|URL=http://www.dub.uu.nl/artikel/achtergrond/bijvoet-centrum-1-ziektes-bestrijden-op-atomair-niveau.html
}}</ref> The Bijvoet Center maintains advanced infrastructures for the analysis of proteins using [[NMR]], [[electron microscopy]], [[X-ray crystallography]] and [[mass spectrometry]].<ref name="MERIL">{{cite web
|title=Bijvoet Center - Bijvoet Center for Biomolecular Research
|website=MERIL - Mapping fo the European Research Infrastructure Landscape
|url=http://portal.meril.eu/converis-esf/publicweb/research_infrastructure/2362
|accessdate=May 2, 2013
|language=English}}</ref>
 
==References==
{{reflist}}
 
==External links==
* The [http://www.uu.nl/science/bijvoet Bijvoet Center] at Utrecht University
 
{{Authority control|VIAF=108202618}}
{{Persondata <!-- Metadata: see [[Wikipedia:Persondata]]. -->
| NAME              = Bijvoet, Johannes Martin
| ALTERNATIVE NAMES =
| SHORT DESCRIPTION = Dutch crystallographer
| DATE OF BIRTH    = 23 January 1892
| PLACE OF BIRTH    =
| DATE OF DEATH    = 4 March 1980
| PLACE OF DEATH    =
}}
{{DEFAULTSORT:Bijvoet, Johannes Martin}}
[[Category:1892 births]]
[[Category:1980 deaths]]
[[Category:Crystallography]]
[[Category:Dutch chemists]]
[[Category:Utrecht University faculty]]
[[Category:People from Amsterdam]]
[[Category:Foreign Members of the Royal Society]]

Revision as of 05:24, 4 January 2014

Johannes Martin Bijvoet ForMemRS[1] (23 January 1892, Amsterdam – 4 March 1980, Winterswijk) was a Dutch chemist and crystallographer at the van 't Hoff Laboratory at Utrecht University. He is famous for devising a method of establishing the absolute configuration of molecules.[2][3][4][5][6][7][8]

The concept of tetrahedrally bound carbon in organic compounds stems back to the work by van 't Hoff and Le Bel in 1874. At this time, it was impossible to assign the absolute configuration of a molecule by means other than referring to the projection formula established by Fischer, who had used glyceraldehyde as the prototype and assigned randomly its absolute configuration.

In 1949 Bijvoet outlined his principle, which relies on the anomalous dispersion of X-ray radiation. Instead of the normally observed elastic scattering of X-rays when they hit an atom, which generates a scattered wave of the same energy but with a shift in phase, X-ray radiation near the absorption edge of an atom creates a partial ionisation process. Some new X-ray radiation is generated from the inner electron shells of the atoms. The X-ray radiation already being scattered is interfered with by the new radiation, both amplitude and phase being altered. These additional contributions to the scattering may be written as a real part f' and an imaginary one, f". Whereas the real part is either positive or negative, the imaginary is always positive, resulting in an addition to the phase angle.

In 1951, using an X-ray tube with a zirconium target, Bijvoet and his coworkers Peerdeman and van Bommel achieved the first experimental determination of the absolute configuration of sodium rubidium tartrate. In this compound, rubidium atoms were the ones close to the absorption edge. In their later publication in Nature, entitled Determination of the absolute configuration of optically active compounds by means of X-rays, the authors conclude that

"The result is that Emil Fisher's convention, which assigned the configuration of FIG. 2 to the dextrorotatory acid appears to answer the reality."

The determination of absolute configuration is nowadays achieved using "soft" X-ray radiation, most often generated with a copper target (which generates X-rays with a characteristic wavelength of 154 pm). Shorter wavelengths make the observable differences in measured intensities smaller, thereby making the distinction of absolute configuration more difficult. The measurement of absolute configuration is also facilitated by the presence of atoms heavier than oxygen.

X-ray diffraction is still considered the ultimate proof of absolute structure, but other techniques such as circular dichroism spectroscopy are often used as faster alternatives.

Bijvoet Center

Mining Engineer (Excluding Oil ) Truman from Alma, loves to spend time knotting, largest property developers in singapore developers in singapore and stamp collecting. Recently had a family visit to Urnes Stave Church. The Bijvoet Center for Biomolecular Research at Utrecht University, which was founded in 1988, was named after him.[9] The Bijvoet Center performs research on the relation between the structure and function of biomolecules, including proteins and lipids, which play a role in biological processes such as regulation, interaction and recognition.[10] The Bijvoet Center maintains advanced infrastructures for the analysis of proteins using NMR, electron microscopy, X-ray crystallography and mass spectrometry.[11]

References

43 year old Petroleum Engineer Harry from Deep River, usually spends time with hobbies and interests like renting movies, property developers in singapore new condominium and vehicle racing. Constantly enjoys going to destinations like Camino Real de Tierra Adentro.

External links

In the event you've just lately been requested by your employer to be posted to Singapore, then this website is for you. Whether or not you're single or married with kids, whether or not you are looking for a condominium, a bungalow, a semi-detached or a public condo, residing and renting a house in Singapore at this time is straightforward when you recognize the ins and outs, the dos and don'ts.

He is a rip-off!! Severely trust me he's on of the scammer agent. He made me believe that I've a spot to remain then when I was about to move the place isn't out there. Then he just took my deposit and agent's charge. By the best way he's also the landlord of the place i am presupposed to lease. He took my money and ran away. However I went to the HDB and complain him, additionally I complain straight to the police. Then the police called him and he got scared. Finally each penny that I gave him, he give it again since HDB and police office is supporting me. Don't be lazy to complain. Go straight to the police and complain these individuals.

i imagine there are good ethical brokers in Singapore. But i have encounter unhealthy experiencing the Christina Fong from realty master. She is admittedly an unprofessional and never moral one. Only considering of undercutiing and squeezing money from ptther people without defending interest of her personal shopper. Proceed to the section Training and look at a map of all worldwide colleges in Singapore or visit the section residential areas for detailed data on the place to stay and why. Information District and Location Have completed no less than 30 property transactions up to now three years. At least 10 of these transactions will have to be for private properties, and at the very least one other 10 needs to be for HDB flats (also known as public housing); Singapore-Indonesia Commercial Affiliation

Agents need to be very resourceful and so they have to work doubly onerous to succeed in out to extra consumers as a result of when the market swings, it turns into very aggressive," said PropNex Chief Executive Mohamed Ismail. "Beforehand, an agent might focus on one space, comparable to HDB, however at this time you may't." An motion for misrepresentation arises beneath the law of tort. A Misrepresentation happens when the Representor (Property Agent) makes a false assertion of existing truth with data of its falsity and with the intention that the Representee (Buyer or Seller) ought to act on it with the consequence that the Representee does act on it to his detriment. Metropolis & South West (D01-08) Tiong Bahru MRT Quiet C/Room F/Furnished w AC No Agent Price

On February 19 we had an appointment with the proprietor and his agent (A and H!) at the condominium to hand over the keys. They went by means of all the things with a wonderful tooth comb. An important lesson we learned over all this is that you simply MUST ENGAGE YOUR PERSONAL AGENT and never rely on the homeowners agent as his priority is to the proprietor not you. Nevertheless, last night time my own agent called me and informed me suddenly that ECG instructed them a buyer goes handy them a check within the morning, so we higher act fast or we may lose the property. Stamp responsibility is to be paid inside 14 days from the date of acceptance of the OTP or Sale and buy a house in singapore (click hyperlink) (S&P) Settlement. For more information, please go to www.iras.gov.sg - Gown Up Your House Woodlands East Industrial & Industrial Affiliation

There may also be a Code of Ethics and a Skilled Conduct Commonplace, as well as the introduction of disciplinary motion in opposition to errant brokers/businesses and dispute decision mechanisms. Preparations shall be made to manage the transition of existing agencies and agents to these new standards, which have but to be finalized. The Proposed Enchancment in High quality for Actual Property Businesses Wheelock Properties put up 95 items of The Panorama in Ang Mo Kio for balloting. With a reduction of 12 p.c, they claimed to promote 80 to eighty five units. Whereas developers are clearing their existing stock, every month there are new projects acquiring their HIGH and new sites released by the government to construct more private housing. The due date of each rental payment; or

To know who pays actual property commissions - whether or not it's sellers or buyers or both or if it is Landlord's or Tenant's or both Divisions vary. All Brokers work on a commission scheme that is determined by the experience, efficiency and various other elements equivalent to recruitment and many others. New brokers can receive from a range of 60%-70% of the full fee received by them from the closure of a deal. High producing brokers would possibly obtain 100% and pay the company (broker) a desk fee. Everybody else falls somewhere in between. Kindly discuss with the FAQ part of the CEA web site-www.cea.gov.sg Co-Broking / sharing of fee There isn't a set formulation. This is based on the demand and supply circumstances in the market. present agents have tertiary education. Template:Persondata

  1. Template:Cite doi
  2. Template:Cite doi
  3. Template:Cite doi
  4. Template:Cite doi
  5. Template:Cite doi
  6. Template:Cite doi
  7. Bijvoet, J. M. Proc. Acad. Sci. Amst. 52, 1949, 313.
  8. Peerdeman, A. F., van Bommel, A. J., Bijvoet, J. M. Proc. Acad. Sci. Amst. 54, 1951, 16.
  9. Template:Cite news
  10. Template:Cite news
  11. Template:Cite web