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druS

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Everything posted by druS

  1. How does one large fan compare to many smaller? Other things being equal the single larger fan will be more energy efficient. But other things are never equal and the centralisation of the duct sytsem will come with more resistant. One thing being missed is static v volume (in the fan selection). So those :"smaller" fans will still have the same static and aren't really smaller at all in the one metric that dictates sizze of motor/power etc. Another thing - ducts can't really be pushed at more than 10m/s, for many reasons. Most designers will work to around 6m/s if they can get away with it. A lot of what is proposed here is impracticable.
  2. Thanks Swansont, it was what i thought I was looking for but turns out you knew better than me. Appreciated. Dru
  3. No doubt at all. Two different things though. The medical advice should be the medical advice. Period. Policy setting should hefor ed that advice but dictate a response that balances things with general matters. In this case those include: 1. the country can't allow students to miss a year of schooling 2. closing schools would have a dramatic impact on health workers who rely on support from the schooling system in order to do their job. 3. drastic measures on the economy have their own impact which will also ultimately impact health of the public as poverty increases. So I can understand a desire by those responsible for the policy settings to keep schools open if it can be justified. But none of that should allow medical advice to be anything other than medical advice. And before we get too down the track of a presumption of political meddling in medical advice, Australia is doing relatively well on a global scale. Our current growth rate is 0.83 and has been below 1 for about two weeks. Our hospitals are about to be permitted to return to elective surgery (important to me as my wife treatment for a brain tumour has been halted) - this because, at this stage, our health system is not a risk of being overwhelmed.
  4. Hopefully during this period of isolation for many of us, someone can find time to check this. Some introductory remarks, this is a maths subject not physics and they really don't care about units but they do care that you simplify the answer as an accurate expression before approximating with the calculator. I have struggled with the differentiation so would appreciate thoughts there. This is just the first part at this stage. QUESTION: The ideal gas law relates the temperature, pressure and volume of an ideal gas. For n moles of gas the pressure P, volume V, and temperature T are related by the equation: PV = nRT Where n is the ideal gas constant. If pressure is measured in kilopascals (kPa), volume in litres (L) and temperature in degrees kelvin (K) then R = 8.3145 kPaL/Kmol. a) Suppose that one mole of ideal gas is held in a closed container with a volume of 25 litres. If the temperature of the gas is increased at a rate of 3.5 kelvin/min, how quickly will the pressure increase? b) Suppose that the temperature of one mole of gas is held fixed at 300K, while the volume decreases at a rate of 2.0 litres/min. How quickly is the pressure of the gas increassing at the instant that the volume is 20 litres? Thanks in advance. Edit: updated with proposed answers to both parts of the Q.
  5. This seems inconsistent with the advice from the Chief Medical Officer in Australia. The view is that the risk of transmission in schools is low and that teachers greatest risk is from other teachers, that parents greatest risk is exposure to other parents during drop off. I understand that schools are a something of a petri dish for many virus, but the view here seems to be that this virus is different.
  6. Presuming that the advice here in Australia is reasonably agreed, we are told that children are relatively minor risk of catching or transmitting SARS-Co2. And of course when they get it are minor risk of severe symptoms. One possible strategy could be to intentionally allow infection on those age brackets. It would help lead toward herd immunity. Now ethically let alone politically I doubt it would be permitted anywhere. HOWEVER - is some form of vaccine that was more aggressive possible for those low risk age groups? Would this assist quicker development of a vaccine. Then for the at risk groups a different more subtle, more tested vaccine be sought in the fullness of time?
  7. On Australia there have been some interesting initiatives to help fill the hand sanitiser gell. One boutique distiller (Archie Rose) has swappedx to ethanol and geared up to produce sanitiser. Similar scenario in some of the grape/wine areas where grapes have been tainted by smoke form the fires and are not usable for producing wine. They are interesting feel good stories, ut to be frank, I still cant obtain any hand sanitiser when I shop.
  8. I have arachnaphobia sufficiently advanced that I have to take time to still my pulse. Pretty sure this started at 4 or 5 years old with my grandfather cutting dead leaves/branches off banana trees. A huge Huntsmen (large friendly harmless useful spider, large being easy 8 inches across) leap from a cut branch onto my head. More recently coming face to face with a funnel web (about the size of the first joint on your thumb and VERY venomous) and this was NOT amuzing. Snakes are a different matter. I was introduced young to very poisonous snakes - first recollection is catching a death adder (venomous stubby fat 2 foot long maybe) , but also the common brown (6 foot, skinny, fast, way aggressive, leave alone). I like snakes. I got a little agitated when my wife nearly walked on top of a red belly black (these guys eat browns) in a state forest a couple of years ago, but as long as we avoided it once seen all good. Get the camera out.
  9. CharonY you continue to fascinate on this thread. Should have started talking about virus a long time ago! Is this "unrecognised domain" part of what I have seen described as "phylum candidate radiata"? By the way, don't plasmids self replicate? That would be a big difference to a virus I suspect. I will have to look up transposons.
  10. Love it Dagl1 - your response tells me I must keep studying! [But also gives me some specifics I want to test as I go forward.] (FWIW I would have thought identical DNA means a clone, I dont think that was the intent of the OP.)
  11. Dagl1, you seem to be reacting in a manner that suggests I am being aggressive against your input? Sorry mate if you think that, but it's not the case. Can I be offered a genuine interest? I would have completely stood by your statement over genomes. Certainly within my understanding of diploid organisms. I put out a query based on ignorance and interest. Let's focus on one single statement from wiki that I quoted In some species, ploidy varies between individuals of the same species. How does this effect genome? Genuine question, no challenge here.
  12. When I first glanced through this thread I scoffed. Misunderstanding about the meaning of genome. But I've been thinking about ploidy and wondering if my response is more about the genomes and chromosome systems that I am most familiar with. From Wiki on ploidy: Many animals are uniformly diploid, though polyploidy is common in invertebrates, reptiles, and amphibians. In some species, ploidy varies between individuals of the same species (as in the social insects), and in others entire tissues and organ systems may be polyploid despite the rest of the body being diploid (as in the mammalian liver). For many organisms, especially plants and fungi, changes in ploidy level between generations are major drivers of speciation. Does this put some reality back in the OP? Thanks in advance.
  13. So the coating is the protein capsid? (In an earlier post of mine there was a spell correct that changed the word). In west and south coast Aus, the weather is drier and less humidity. On the east coast and the north it is the opposite - but we still get seasonal flu. Either way we can only expect approaching winter to impact while approaching su8mmer in the northern hemisphere hopefully gains benefits. Fascinating what we do and don't know. Zapatos - from what we are hearing the symptoms could be symptoms of many many things of which only one is CV-19. FWIW some statistics in NSW Australia - reference: https://www.health.nsw.gov.au/news/Pages/20200316_02.aspx Total number of tests: 26 964 Tested and excluded: 25 511 Under investigation: 1 282 Confirmed positive: 171 Every country will have a different experience based on how accurate they are with who gets tested, and where they are on the curve. But as above under 1% confirmed approx 95% excluded.
  14. Understand the strategy. What I am not seeing is the social reality here in Australia, and i suspect that Australia has handled the matter better than many countries. There is an expectation that Summer will see a seasonal die-back in transmission, but here in Australia ALL of CV-19 cases have been contracted in Summer (or the summer shoulder). See rather than a natural die-back we would anticipate an increase in transmission. Currently a lot of thinking is short term eg the recent border closure (term used for convenience, you can enter but must voluntarily isolate for two weeks on arrival) and people are saying "just give it a couple of weeks to settle so we can understand what we are dealing with". But we should know that while a vaccine can be expected it will be 12 to 18 months. On the shorter scale it means availability of vaccine in the approaching winter of 2021, or on the longer scale deep into that winter. In the mean time we seem to be saying that slowing CV-19 down requires quite anti-social measures on more than a short term basis. CharonY, are you up to expanding on this a little? For background I have just completed my first biology unit in a science degree where one module was molecular biology. Enough knowledge to pretend to be dangerous lol. From recollection, a virus is a small chain of either single or double strand DNA or RNA. Am I correct in reading CV-19 as single strand DNA? The Virus has a consisting created by proteins (I had thought a single species but apparently not). And possibly some borrowed membrane from the host cell. Where does it pick up the polymerase?
  15. All good. I do appreciate the response. On human behaviour for a second transmission - presuming that only a small percentage of the population was exposed in the initial transmission, and no vaccine - how is it controlled by social behaviour. Sorry that seems daft. The first time round China "missed" it early, then got it under control with draconian measures. The current advice is wash hands, social distancing, self isolation, etc. But those measu4res during the first transmission (here is Australia anyway), don't seem to be expected to achieve more than "slow it down". Does it mean that little short of draconian measures are enough until a vaccine is available?
  16. Odd, looks like you are taking issue with the tone of your own response? "How is this a question for you" - FWIW, it is simple curiosity, they seemed to have determine stability (lack of mutation) quite early, other corona virus mutate do they not? Surely developing vaccines is a more challenging task if the virus is changing.
  17. Like Externet I am curious on a couple of issues: How do you "kill" a virus given that they are not life forms? Why would a period of time render them redundant? Is not the common cold a corona virus? Have they not been trying to develop a vaccine for decades? If that is the case, what is the basis for confidence that a solution (vaccine) to Covid-19 will be achieved in months? (Given this needs to happen for a vaccine to be available in 12-18 months). I have read somewhere that Covid-19 is not mutating (rapidly like flu anyway). How do they determine that? China looks well to have caught the situation. I understand that secondary transmissions can be expected in epidemics and indeed I see that this happened for Spanish flu. How does that work and what is the likelihood in, say China (but anywhere really), while there is no vaccine? What rate of exposure and adaptive immune response is required in a population to have the matter under control? I refer here to vaccines for things like measles which require a certain level of immunisation to control the disease - which is not 100%. Cheers
  18. I had thought that said there was increasingly a will to investigate quantum foundations with broader thinking than the Copenhagen interpretation. Everett inspired many worlds interpretation has followers, there is even some work, I understand, on pilot-wave interpretation. I'm unsure on what developments in quantum holography and quantum information provide but it is further work in the area. Clearly the body of knowledge that is quantum mechanics, remains highly precise and successful, but this hasn't meant that quantum foundations are not being further considered. Examples: Einstein's Unfinished Revolution, The search for what lies beyond the quantum: Lee Smolin What Is Real? The unfinished quest for the meaning of quantum physiscs: Adam Beckler Note to the OP - this is an easily read and digested run through the topic. Something Deeply Hidden, Quantum worlds and the emergence of spacetime: Sean Carroll [Admit to having not read this yet, though I have listened to his podcasts and most of his available lectures] As an interested non-expert (I am working on it!) it appears that there is plenty happening in an areas previously considered effectively settled.
  19. Out of interest to the greater wisdom here - I would not expect that sin of all angles can be defined exactly. Perhaps using limits/infetesimals?
  20. Apologies in advance on being a little disconnected in my thinking here - emergence does that to straight thinking I find. I've not been convinced by the typical definitions of life trotted out for students (such as myself). As you say CharonY they tend to describe features of life as we understand it here on earth. [That in itself is somewhat incomplete.] Which is somewhat limiting. I'm also not convinced of definitions which exclude virus ( on the basis of not passing on hereditary information, and I guess, homeostasis/metabolism). It seems to me that if we find an extraterrestrial virus scientists would not just be excited but would be reconsidering those definitions. I can imagine an electronic AI that I would be tempted to call life, that wouldn't meet any currently recognised definition. Suggests a potential problem with the definition. The topic of emergence borders on the metaphysical but that does not seem to bother theoretical physicists at all. Though Science Philosophers seem to mostly to start with a position of the topic being junk. There is a boundary being used, especially in areas such as quantum foundations, that does not seem to robustly fit Popper. Emergence seems based on "well, we can't rule it out!", rather than any deeper foundation. I find it hard to simply accept as tabled. On another note, the earlier OP, seemed without stating it to be talking not just life but conscious life - which is another step entirely.
  21. allison, if that doesn't seem clear. The X and Y chromosomes kick off hormosomal changes such as puberty. The hormones involved can then influence genes that are not themselves located on the X or Y chromosomes. Hence "sex influenced". "Sex Linked" means that the gene is physically on the X or Y chromosomes. Inheritance can be quite distinct with sex linked genes, as the Y chromosome is MUCH smaller than the X chromosome and is missing many genes that are on the X chromosome. (While there are Y linked allelles, the X linked can be more obvious). Many X linked genes have no corresponding gene on the Y chromosome. So inheritance is entirely determined by the X chromosome for sons with those X linked genotypes. Hope that helps.
  22. Not sure on thison your specific query, but to ignite the fuel has to be gasified. It is the gas that then ignites. There is a definite step process happening for fire.
  23. That’s exactly the point Dagl1. If you want quick knowledge start with a model organism because we already know a great amount about them.
  24. Fist year biology assignment. It isn't really about the topic itself but about: experience with literature search Scientific writing and referencing Must include 3 references to peer reviewed journals Technically correct scientific terminology The topic is Cas-9, I have chosen agriculture. The assignment needs to provide a background to gene editing, outline of Cas-9, outline of beneficial work, then ethical considerations. I can post the whole assignment if needed. For now my challenge is fine tuning database search between information overload to nothing when I want specifics. I'm doing fine getting an overview of the topic so far, but a refined search is failing me. Those specifics (at the moment) are trying to find seminal journal articles for: 1. Repeat palindromes found in halophiles - by Francisco Majica 2. Subsequent purpose discovered (viral defence) by Horvarth. If I can nail this, then I'm on to Talen, ZFN, embryonic stem cells and pluripotent ES (my term not scientific) Cheers Dru
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