Newsgroup: it.hobby.scuba
Titolo: teklist ovvero: meglio controllare le fonti

Ecco i testi di due mail, una di Erik Baker comparsa tempo fa su
una lista a tema, seguita dall'ultimo messaggio di Roberto
Baraldi sulla teklist. Potete notare che nell'elenco puntato in
5 punti, tutte le occorrenze di VPM, sono state sostituite da
RGBM. Non è necessario leggere l'inglese per vedere se due testi sono
uguali.
Buone bolle
=========================================
August,21th 2001. Erik Baker
=========================================
Hi Stuart, Gordon, and Ross,
Thanks for the detailed feedback on your experiences with the
VPM algorithm.  And for being trailblazers (albeit with some
joint pain along the way in Stuart's case).
.....cut......
Some thoughts come to mind as I review the recent dive reports:
1.  The VPM algorithm appears to be doing what its supposed to -
      that is limit the formation of bubbles during ascent to
      the surface.  This would help to explain why divers are
      not feeling fatigued after the dives or why symptoms, if
      any, seem to resolve relatively quickly.
2.  The VPM uses the standard half-times of Buhlmann (or any
      other dissolved gas algorithm) for computing gas loadings
      and this is done with symmetrical uptake and elimination.
      The fact that less time is required at the shallow stops
      means that divers will be carrying higher gas loadings in
      certain compartments upon surfacing.  The computed gas
      loadings are predicated on the assumption that the diver's
      perfusion system is working "properly" and effectively to
      eliminate dissolved gas at rates correlating with the
      compartment half-times.  However, we know that factors
      such as cold, dehydration, constricting dive suits, etc.,
      can effectively alter the rate of inert gas elimination.
      This situation is not explicitly factored into the present
      VPM algorithm.
3.  Upon surfacing, the gas loadings in some of the compartments
     are higher than allowed by a conventional algorithm, but
     relatively free of bubbles.  However, the gas loadings are
     very close to the line for bubble formation (for the
     specified critical radii) and any sudden decrease in
     ambient pressure could trigger the excitation of bubbles.
     Another bubble forming factor could be localized
     reductions of ambient pressure in joints due to
     movement of limbs and strenuous exercise.  In other
     words, the diver is relatively bubble-free upon
     surfacing, but it won't take much exertion or movement
     to trigger bubbles until the gas loadings are dropped by
     a certain amount.  This may be a prescription for continued
     oxygen breathing on the surface before getting out
     of the water (surface deco) or immediately after getting
     back on the boat.  It sounds like any kind of exertion
     (including hauling gear) should be avoided for some period
     after completing the dive on a VPM deco profile (30 minutes
     to 2 hours?).
5.  The shorter time at the shallow stops of a VPM profile may
     not really mean a drastic reduction in the total deco time,
     but rather it results in the desireable trade-off of being
     able to do your last O2 stop on the surface or on the boat
     versus doing it in the water. . . (just a thought).
5.  The greatest pressure-volume changes occur in the last 20
      fsw / 6 msw of the dive, and especially upon surfacing.  A
      very slow final ascent from the last stop to the surface
      is recommended and exertion should be avoided upon
      surfacing.
6.  Pre-existing injury sites, deco-related or otherwise, are
     highly susceptible to recurring symptoms of DCS.  This is a
     topic I want to address in another post based on the recent
     experiences of a diver-friend of mine.
Keep up the good exchange of information and, as they say, "be
careful out there."
~ Erik
========================================
Baraldi, teklist 12.3.2002
========================================
Come da qualche anno in qua, anche per questo l'assistenza
tecnica Abyss sarà presente all'Eudishow. Ovviamente non allo
stand HdueO, che quest'anno non sarà presente, ma gentilmente
ospitata presso lo stand dell'Aerotecnica Coltri Padiglione 15 -
Area B4/5, precisamnete nell'area riservata ai club subacquei
veronesi tra i quali troverete ASSOSUB VERONA. Proprio li
troverete il solito pc con la più recente versione di Abyss e
tutte le risposte ai vostri problemi di installazione e
manutenzione del software in oggetto. Voglio ricordare a tutti
che è stata rilasciata la versione V2.30 italiana con il nuovo
algoritmo RGBM e l'esportazione delle tabelle in formato Excel.
Di seguito alcuni commenti sul nuovo algoritmo.
Erik Baker offered some good thoughts on using a Bubble model.
1.  The RGBM algorithm appears to be doing what its supposed
      to - that is limit the formation of bubbles during ascent
      to the surface.  This would help to explain why divers are
      not feeling fatigued after the dives or why symptoms, if
      any, seem to resolve relatively quickly.
2.  The RGBM uses the standard half-times of Buhlmann (or any
      other dissolved gas algorithm) for computing gas loadings
      and this is done with symmetrical uptake and elimination.
      The fact that less time is required at the shallow stops
      means that divers will be carrying higher gas loadings in
      certain compartments upon surfacing.  The computed gas
      loadings are predicated on the assumption that the diver's
      perfusion system is working "properly" and effectively to
      eliminate dissolved gas at rates correlating with the
      compartment half-times.  However, we know that factors
      such as cold, dehydration, constricting dive suits, etc.,
      can effectively alter the rate of inert gas elimination.
      This situation is not explicitly factored into the present
      RGBM algorithm.
3.  Upon surfacing, the gas loadings in some of the compartments
     are higher than allowed by a conventional algorithm, but
     relatively free of bubbles.  However, the gas loadings are
     very close to the line for bubble formation (for the
     specified critical radii) and any sudden decrease in
     ambient pressure could trigger the excitation of bubbles.
     Another bubble forming factor could be localized
     reductions of ambient pressure in joints due to movement
     of limbs and strenuous exercise. In other words, the diver
     is relatively bubble-free upon surfacing, but it won't take
     much exertion or movement to trigger bubbles until the
     gas loadings are dropped by a certain amount.  This may
     be a prescription for continued oxygen breathing on the
     surface before getting out of the water (surface deco) or
     immediately after getting back on the boat.  It sounds like
     any kind of exertion (including hauling gear) should be
     avoided for some period after completing the dive on a
     RGBM deco profile (30 minutes to 2 hours?).
5.  The shorter time at the shallow stops of a RGBM profile may
     not really mean a drastic reduction in the total deco time,
     but rather it results in the desirable trade-off of being
     able to do your last O2 stop on the surface or on the boat
     versus doing it in the water. . . (just a thought).
5.  The greatest pressure-volume changes occur in the last 20
     fsw / 6 msw of the dive, and especially upon surfacing. A
     very slow final ascent from the last stop to the surface is
      recommended and exertion should be avoided upon surfacing.
6.  Pre-existing injury sites, deco-related or otherwise, are
     highly susceptible to recurring symptoms of DCS.  This is a
     topic I want to address in another post based on the recent
     experiences of a diver-friend of mine.
Roberto Baraldi
Abyss, supporto tecnico Italia
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 Ecco i testi di due mail ...
Trasformismo algoritmico o che altro ?
Max max

 uguali.
Effettivamente Baker è noto per i suoi studi sul VPM, non sull RGBM.
Se le cose fossero andate come dai ad intendere tu, si tratterebbe di un 
caso di plagio abbastanza pesante.
Da che lista è stato tratto il messaggio originale di Baker ?
Giovanni

 wrote:

giuvà sei ancora vivo.... nonostante tutto?
stai attento che poi ti scotti.......:-)))))
maurizio barbs

    Ho scritto all'interessato e.... come c'era di immaginarsi
si tratta di un plagio non si sa bene fatto da chi ;). Non credo
che la cosa finirà qui, in tutti i casi è un'operazione misera
ma veramente misera....
    Ciao, C.

ma veramente misera....
hai dimenticato ...e coerente.

 ha scritto nel messaggio
news:JKlm8.12547$S52.3...@news2.tin.it...


p.s.: l'hai comprato l'analizzatore dell'elio per analizzare la best mix?
Non io ma qualcuno di noi si.
ciao.