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drol

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Everything posted by drol

  1. drol

    Dilip Kumar

    Saira Banu's mental health has much deteriorated according to her friends.
  2. drol

    The 100 Club

    So real ages may be 94 for Saalumarada and Fauja, 105 for McLaurin. Still impressive ages, but nothing comparable to their unsubstantiated claims.
  3. drol

    Nobel Prize In Death

    First thought is this fucker could die three years ago as I was working way more on OLEDs. OLEDs are light emitters exploiting an organic material, usually a polymer or a blend, and in general something that does not pack well (i.e. amorphous rather than a crystal). The active layer(s) is put between two electrodes, a cathode which injects electrons into the material LUMO and an anode injecting holes (i.e. subtracting electrons) from the material HOMO. Those would be CB and VB in inorganic LEDs. Due to the applied potential holes and electrons move inside the material. When a hole finds an electrons they shall form a quasiaparticle called exciton, which is held together by Coulombic interaction between the positive hole and the negative electron. Excitons exist only in organic matter, as its dielectric constant is way lower than inorganic material. An exciton shall then decay (i.e. recombine hole and electron) either radiatively, and that's what you want there, or non-radiatively, i.e. dissipating heat. Obviously the colour of the emitted light will depend on the HOMO-LUMO gap. Different polymers have different HOMO-LUMO gaps, which can be modulated depending on conjugation length and chemical functionalization. The electroluminiscence yield of an OLED will depend on: 1)The material quantum yield (if kr is the radiative decay constant the yield is QY=kr/(kr+knr), where knr is the non radiative decay constant. It could be easily shown this equates to the ratio between absorbed and emitted photons). 2)The ratio between holes and electrons inside the material. If it is one virtually there could be as many excitons as holes. This ratio is linked to the kinetic barriers for injection (so on the HOMO and LUMO energy levels again) and to the transport properties of the materials. 3)The ratio of singlets to total states. This is normally 25% as when you inject a hole and an electron they are both doublets (S=1/2) and due to angular momentum coupling you get the exciton as 3/4 a triplet, 1/4 a singlet. Sadly triplets are usually not emissive, as they have no dipole moments with the singlet ground state. Therefore 75% of formed excitons are wasted. Any of these three factors can be improved to raise OLED electroluminescence efficiency. For 1) you should use cis/trans mixtures, blends or other things which do not tend to cristallyze. What's the problem with crystals? Usually aromatic polymers crystallize forming so-called H aggregates. A H-aggregates is not fluorescent (or very weakly, due to vibronic coupling). So fluorescence would be easily suppressed. Approaches for 3) are the most interesting. If you use heavy metals (devices are called PHOLEDs) like Pd, Rh, Ir, exc then you get the spin-orbit coupling you need in order to mix the spin and spatial parts of the wavefunction. Due to mixing with the adiacent single state the triplet becomes emissive, although with a much longer lifetime. This is called phosphorescence. Then 100% of excitons could be virtually used for light emission! What are the problems with this? 1)Cost and toxicity of heavy metals. Mainly. 2)Due to Hund's rule triplet energy is lower than singlet energy. It is difficult to have a PHOLED which is efficient in the blue (and you strongly need blue OLEDs in RGB). Various approaches are being developed. I'll mention purely organic phosphorescence, Triplet-Triplet Annihilation (TTA) and Thermally Activated Delayed Fluorescence (TADF). This last one would repopulate (a process called RISC) the singlet states from the adjacent triplet state using thermal quanta at room temperature. Since this falls at 200 cm-1 in the microwaves, you need very close singlets and triplets. That's where chemical design comes into play.
  4. drol

    Thoughts On The 2022 List

    Not going well, both because there have hardly been notable deaths recently and because the list is pretty bad.
  5. drol

    The 100 Club

    Because she is eight years younger of her claimed age, and that's pretty much documented, but she and her family insist.
  6. drol

    World's Oldest

    She is now 6 minutes closer.
  7. drol

    The 100 Club

    Here's a friendly quick advice for age fraudsters Virginia McLaurin, Saalumarada Thimmakka and Fauja Singh.
  8. drol

    Military commanders

    Zou Yan, one of the remaining founding Major Generals of PLA, prematurely dead at 106. Five of them left, ages between 99 and 109.
  9. drol

    The 100 Club

    FTFY.
  10. Kassa was born in 1944.
  11. drol

    The 100 Club

    Masao Horie dead at 106.
  12. drol

    Your DDP Salvage Lot 2022

    Miguel Van Damme dead at 28.
  13. drol

    Hospitalised!

    The Enrique Pinti is dead.
  14. drol

    Heartache club

    Don't waste yourself that way.
  15. drol

    Hospitalised!

    So Toshack and Furino both discharged, Sanchez will be discharged today. A bad record indeed.
  16. drol

    Death, Italian Style

    Controversial rapper/influencer Fedez (wiki) received surgery for pancreatic cancer. Guaranteed to QO, seems to have been caught very early. Also suffering from autoimmune disease if I remember well. Only 32.
  17. drol

    The 100 Club

    Abd-al Minaan Khaleel dead at 100.
  18. drol

    The 100 Club

    Noted for commanding the anti-aircraft which took down Francis Gary Powers. Powers's story is featured in Bridge of Spies
  19. drol

    Who are the immortals?

    We'll see how we look at 107!
  20. drol

    Who are the immortals?

    Will never stop living actually! Ma Shitu now able to walk unaided and exercise in his garden. Did these fuckers find the Fountain of Youth?
  21. drol

    African Leaders - Despots and Democratic

    Very good hint, in fact Jacob Oulanyah is dead.
  22. drol

    Political Frailty

    Living vice chairmen/women of CPPCC: 1)Pagbalha Namgyal (1940): Tibet Lama who has served in the position from 1959 and 1993 and from 2003 to our days. 2)Yan Mingfu (1931): Tien An Men hero, suffering from a degenerative illness since at least 2012. 3)Wang Zhaoguo (1941) 4)Qian Zhengying (1923): politician and academic, ancient and quite frail on her 98th birthday. 5)Ren Jianxin (1925): Supreme court president who has been out of the public eye for years. 6)Song Jian (1931): legendary aerospace engineer. 7)Li Guixian (1937) 8)Zhang Siqing (1932) 9)Hu Qili (1929): "on his deathbed" in August 2018, now well enough to make public appearances and organize golf tournaments. 10)Bai Lichen (1941) 11)Zhang Kehui (1928): Taiwan pro-Bejing politician who was already frail in 2009, but still granting interviews in 2017. 12)Zhong Tienong (1938) 13)Wang Zhongyu (1933) 14)Liao Hui (1942) 15)Hao Jianxu (1935) 16)Chen Kuiyuan (1942) 17)Abdulahat Abdulrixit (1942): Uyghur loyalist of Bejing. 18)Xu Kuangdi (1937), also mayor of Shanghai, but did not follow Jiang and Zhu careers. 19)Zhang Huaixi (1935) 20)Li Meng (1937) 21)Tung Chee-hwa (1937): rumoured to be gravely ill, received surgery in October. 22)Zhang Meying (1937) 23)Wang Gang (1942) Damn, these people are longeve.
  23. drol

    Boxing Clever?

    Legendary Brazilian boxer Eder Jofre receiving treatment for pneumonia.
  24. drol

    Who are the immortals?

    Shahabuddin Ahmed (1930-2022) "Whooooooo?" (Every Bangladeshi reaction to Shahabuddin's untimely demise) Age at death: 92 Known health issues: Come on, that fucking picture is from 2018! Ill in 2017, gravely ill in 2020, critically ill in 2022. Cause of death: Natural causes. Alignment: Now imagine a very charismatic man. Ok. That man is not Shahabuddin.
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