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Posts posted by Endy0816

  1. 20 hours ago, studiot said:

    Every degree above the optimal represents wasted heat and possibly dangerous conditions.

    Do you like being suddenly scalded in the shower ?


    Sorry, maybe should have been more clear but you need lower temperatures in general.


    You want to go from a gas back to a liquid. You need the return line at a cool enough temperature for that.



  2. 3 hours ago, studiot said:

    I think it is rather more complicated than that.

    The lower the input temperature the more heat you need to raise the water to the fixed output temperature.

    It also need to be considered whether the boiler is running in DHW or CH mode.

    But it is good to discuss these things to gain understanding.

    Think ideally your output temperature should vary based on heating load. If return temperature isn't low enough you won't be able to steal back the latent heat locked away. Does take the correct setup to really see the benefits.

  3. 1 hour ago, MigL said:

    What happens at the far left of that graph, when the inlet water temperature drops to 00 C ?
    You would have a nasty discontinuity ?

    Literally, as ice will start forming lol.

    5 hours ago, studiot said:

    In particular your graph show boiler 'efficiency' falling dramatically with rising water inlet temperature, which begs the question of what is meant by efficiency?

    The lower the inlet temperature, the more heat can be recovered via phase change.


  4. 1 hour ago, Marcus Vinicius said:

    Reproductive cloning is a method in which the DNA of an egg in an organism (A) is derived and, subsequently, the DNA of a somatic cell in an organism (B) is placed in the egg. After that, a new organism (C) with the same genome as (B) will be created. What do you think of this technique?

    Me: I would like to have a clone of myself. But I think it is bad for humanity in general, because if everyone starts to clone themselves, we would no longer have genetic variability, and that could cause several weaknesses of diseases for example.

    Depends on to what extent it is used and how the population is distributed. Cloning offers a route to rapid population growth/recovery.

  5. They had a couple of different systems they turned to.



    Large numbers

    During the centuries that Roman numerals remained the standard way of writing numbers throughout Europe, there were various extensions to the system designed to indicate larger numbers, none of which were ever standardised.


    "1630" on the Westerkerk in Amsterdam. "M" and "D" are given archaic "apostrophus" form.

    One of these was the apostrophus,[46] in which 500 was written as IↃ, while 1,000 was written as CIↃ.[20] This is a system of encasing numbers to denote thousands (imagine the Cs and s as parentheses), which has its origins in Etruscan numeral usage. The IↃ and CIↃ used to represent 500 and 1,000 most likely preceded, and subsequently influenced, the adoption of "D" and "M" in conventional Roman numerals.

    In this system, an extra denoted 500, and multiple extra s are used to denote 5,000, 50,000, etc. For example:

    Base number   CIↃ = 1,000 CCIↃↃ = 10,000 CCCIↃↃↃ = 100,000
    1 extra IↃ = 500 CIↃↃ = 1,500 CCIↃↃↃ = 10,500 CCCIↃↃↃↃ = 100,500
    2 extra s IↃↃ = 5,000   CCIↃↃↃↃ = 15,000 CCCIↃↃↃↃↃ = 105,000
    3 extra s IↃↃↃ = 50,000     CCCIↃↃↃↃↃↃ = 150,000
    Page from a 16th-century manual, showing a mixture of apostrophus and vinculum numbers (see in particular the ways of writing 10,000).

    Sometimes CIↃ was reduced to for 1,000. John Wallis is often credited for introducing the symbol for infinity (modern ∞), and one conjecture is that he based it on this usage, since 1,000 was hyperbolically used to represent very large numbers. Similarly, IↃↃ for 5,000 was reduced to ; CCIↃↃ for 10,000 to ; IↃↃↃ for 50,000 to ; and CCCIↃↃↃ for 100,000 to . [47]


    Another system was the vinculum, in which conventional Roman numerals were multiplied by 1,000 by adding a "bar" or "overline".[47] It was a common alternative to the apostrophic ↀ during the Imperial era: both systems were in simultaneous use around the Roman world (M for '1000' was not in use until the Medieval period).[48] [49] The use of vinculum for multiples of 1,000 can be observed, for example, on the milestones erected by Roman soldiers along the Antonine Wall in the mid-2nd century AD.[50] There is some scope for confusion when an overline is meant to denote multiples of 1,000, and when not. The Greeks and Romans often overlined letters acting as numerals to highlight them from the general body of the text, without any numerical significance. This stylistic convention was, for example, also in use in the inscriptions of the Antonine Wall,[51] and the reader is required to decipher the intended meaning of the overline from the context. The vinculum for marking 1,000s continued in use in the Middle Ages, though it became known more commonly as titulus.[52]

    Some modern sources describe Vinculum as if it were a part of the current "standard":[53] however this is purely hypothetical - since no common modern usage requires numbers larger than the current year (MMXXI). Nonetheless, for reference: here are some examples, to give an idea of how it might be used::

    • IV = 4,000
    • IVDCXXVII = 4,627
    • XXV = 25,000
    • XXVCDLIX = 25,459


  6. On 1/6/2021 at 11:28 PM, npts2020 said:

    How, then, does a nuclear powered aircraft carrier go from all stop to full speed ahead in a short period of time?

    At least with a Sub I'd say it's fairly sluggish about accelerating. You can't demand too much from your steam or reactor in too short a time.

  7. 6 hours ago, studiot said:

    Should car manufacturers blame road design and construction or themselves if their technology fails to account for all road types ?


    To some extent everything can be fooled by optical illusions, though one could make the case that adequate testing is needed to ensure a reasonable level of performance.

    Not sure who or what should determine that level though.

  8. 1 hour ago, Olorin said:

    The hole in the ozone layer is, for starters, in the wrong hemisphere. Population, industry and land surface area testify to that. Chloroform Ch3Cl doesn't burn, Carbon Tetrachloride CCl4 was used as a fire extinguisher until people died when it formed phosgene gas COCl2 with hot iron, which gas was used in WWI to kill enemy troupes, but causing continuing problems much as agent orange has for veterans. Phosgene is still used to create insecticides and herbicides. Poison dart frog toxins are chlorofluorocarbons or CFC's. Carbon Tetrachloride was also discovered to cause instant fatal renal failure, while sold as dry cleaning fluid. The common factor in these deaths was alcohol in the blood of the victims, and it was banned. 

    The claim that the ozone layer is leached by CFC's, even supplying some supposed chemical equations, seems unlikely. Class actions may have been threatening, besides the inability of natural processes to remove them from the environment, where they concentrate up the food chain. Ozone is a powerful oxidising agent. The solar wind consists of protons and electrons and the protons head south. They are oxidised by ozone O3 and even by ordinary oxygen O2, creating water missing an electron. This discharges slowly, or by producing red meeting the discharging green electrons rising in aurora Australis, or as red sprites drawn by lightning strikes (electrons rising) and manifesting above storm clouds. Borealis is normally green as electrons descend to earth. Possibly the current here implied contributes to the earth's shifting magnetic field.


    The atmosphere under the geomagnetic poles isn't as protected as the rest. CFC's were still ultimately causing the problem though.


  9. 3 hours ago, studiot said:

    Since neither of you are english, you may not be familiar with the english expression "Brute force and ignorance" as some method   'any fool (or monkey) could employ'.

    Think makes more sense to evaluate based on the time and the resources each method takes.

    You don't want to spend forever on something the computer can brute-force for you. Password cracking for example.

  10. On 12/23/2020 at 5:15 PM, swansont said:

    A sail exerts a force from an external source (the wind)

    This works by taking the emanations of the sun and pushing them back onto the sun.

      I think it is supposed to count as it is itself using the sunlight to remain stationary.

    Had a thought that you could shield the sun, bringing the heliosphere in and perhaps truly sail via the passing interstellar medium. I've never seen analysis for that one though.

  11. People, on average, earn more where it costs more to live. This doesn't necessarily mean they're any more industrious though.

    In reality I think this would just reduce the available supply, rather than cut into the Airbnb or real-estate speculation culture.

  12. 11 hours ago, bearnard44 said:

    As far as you may know, scientists found a huge amount of water on Mars. I`ve been wondering for a while if that water is contaminated with radiation because of the high level of radiation on the red planet?

    Probably is radioactive dust on/in the surface ice but underground water should be okay.

    I'm thinking that as it is probably saltwater, we'll remove any contaminants at the same time as we are desalinating.


  13. 1 hour ago, RamaRaksha said:

    The point of the post is that there is only one World - this one! No running away and hiding in some magic land in the sky. God is not a Sugar Daddy, He is not running a Retirement Home in the sky. So those vermin is YOU or your friends, buddy

    They or I would then reincarnate. Is suffering not part of existence until reaching Nirvana?

    Not sure about Hinduism, but there are realms in Buddhism that might be said to be what the Christian faith considers as Heaven and Hell.  Perhaps Christianity is simply mistaken about their nature. Who can say?

  14. 9 hours ago, swansont said:

    Where does the solar sail attach?

    Be via gravity.


    Shkadov thruster (named after Dr. Leonid Shkadov who first proposed it), or a Class A stellar engine.[4] Such an engine is a stellar propulsion system, consisting of an enormous mirror/light sail—actually a massive type of solar statite large enough to classify as a megastructure—which would balance gravitational attraction towards and radiation pressure away from the star. Since the radiation pressure of the star would now be asymmetrical, i.e. more radiation is being emitted in one direction as compared to another, the 'excess' radiation pressure acts as net thrust, accelerating the star in the direction of the hovering statite. Such thrust and acceleration would be very slight, but such a system could be stable for millennia.



    9 hours ago, swansont said:

    Mass ejection just compounds the problem you are trying to solve.

    The alternative Caplan thruster, would cost some of your hydrogen and mass, but you would be headed to 'fill-up' and need to lose some byproducts anyways(if the size is to be maintained).


  15. 4 hours ago, MigL said:

    I can see other problems also.
    The gas giants, Jupiter, Saturn, Uranus and Neptune, are sizeable enough that inertial effects on acceleration ( of the Sun ), would cause disruptions to their orbits; which would, in turn, affect even the smaller 'rocky' planets.
    You might move the Sun, but it may arrive at its destination without planets.

    Yeah this would definitely be more K2 Civilization type stuff.  I'd dread to see the math you would have to do to figure out how to do it safely, not to mention when your civilization finally arrived somewhere.

  16. 2 hours ago, swansont said:

    How would you move a star several LY to get to another star? 

    For a Stellar engine, you would use a portion of a star's own energy to do so.

    Basic ideas are to either use the mother of all solar sails or deliberately caused mass ejections.

    Would be slow though which might still pose a problem.

  17. 6 hours ago, swansont said:

    Even if this were the solution, the answer would be “no”

    the sun’s mass is 2 x 10^30 kg, and largely hydrogen. The earth’s mass is 6 x 10^24 kg, and only a tiny fraction of that mass is hydrogen.

    So where would you get enough hydrogen to make any noticeable difference?

    Could in theory move it elsewhere and supply it with gas giants and material from other stars.

    Personally I suspect it'll become more a matter of how economic man-made Fusion reactors end up being though.

  18. 7 hours ago, ahmet said:

    thank you for the comment and/or help.  Do you mention wordpress or something like this? 

    I did not understand the last sentence of this paragraph. 

    but I can say that in that mentioned book,I would not take pictures  or any else information except the codes. 

    if you recommended me wordpress..then first this seems like to escape to/through easy way. second, they use strict javascrip codes that I would not be able to dominate them well.In fact, I can normally develop very good webpages but being very busy these days , having a regular responsibility and something like these are all making it almost luxury to deal with anything else. (sorry  really I am really not a lazy one..maybe postponing something be good for a while)

    thanks again.

    Yes, something like wordpress though naturally you should search for a website builder or template that has what you are looking for.

    By the last sentence I mean that you can replicate how a site looks in the browser. What matters is that the code is mostly your own work or code you've obtained legitimately.

    Good that you're not planning to copy pictures. The main problem with simply copying code is that it may not behave the same. Better to only copy what you need and then know for certain how your website will behave.

  19. 42 minutes ago, ahmet said:

    hi again;

    can someone analyse this for me: 

    I know a bit html + css (intermediate level)

    and entry level javascript. that mentioned part of book is about a design of webpage. 

    I sent request to them two times but could not take a reply unforunately. 

    so, could someone analyse this for me:

    i will use the outline scheleton or structure of the design (of webpage). (But I shall change almost all of css codes and some html's)

    so, will  this still require me to obtain/take the consent??

    Strictly speaking, yes. It is copyrighted but pretty rare a case is made over reuse. What normally gets people into trouble/caught is hotlinking(linking to someone else's files) and stealing images, however.

    I'd recommend using one of the free website builder(or similar tools) that exist instead if you can.  It is perfectly legal to replicate the appearance of a site you're interested in.

  20. 2 hours ago, CuriosOne said:

    Oh, I thought capitol x as in capital X had some relavance....lol

    There is something else, I must add...

    Saw this in a conversion base "calculator" as I stumbled on..

     "quotient" of "Base Systems"???

    As in "The Difference Quotient?"

    Used in calculus??

    How Odd!

    Where do those sum remainders go??


    That looks off but if you choose something like

    6 to base 2

    Division Quotient


    6/2 3 0  
    3/2 1 1  
    1/2 0 1  

    Reassembling the remainders from bottom to top, you get 1 1 0

    so One-One-Zero in base-2 or 1102 = 610


    Bases come  into play with logarithms in calculus.


    log base-b, with the typical base you'll use being an unspoken 10.

    log10(100) = 2


    1 hour ago, studiot said:

    The story of how we got from there to here (today) is quite interesting.

    Indeed. I still wonder if we'll ever switch from predominantly using base-10 again. Interesting to consider.


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