The model that the blower manufacturer ran to select the blower says the blower requires 47HP at the shaft. I've got a 60HP motor on the blower. So I should be good there. The motor and the VFD have both been checked and they are both functioning properly.
How do scientists determine the half-life of radioactive isotopes? It seems like it would be difficult for elements that have a half-life measured in billions of years. What's the level of accuracy for these measurements?
You don't have to have it decay to it's half life to determine the value for it. It's an exponential decay problem. You simply measure the isotope at one period of time and then measure it again later. Then you can use math to determine the half life. For example, one formula you can use for half life is N(t)=N(0)*(1/2)^(t/t_0.5) Where t is the time elapsed, N(t) is the amount left at time t, N(0) is the initial amount and t_0.5 is the half life. Measuring at two different times, you then simply solve for t_0.5 to get your halflife. The accuracy will depend on the experiments conditions. Things that would affect the accuracy would probably depend upon: *The uncertainty in your time measurement *The uncertainty in the measurement of your isotope's amount *Whether the sample is pure or has other isotopes in it with different half lifes That sort of thing. They would take multiple measurements using different samples and different time lengths to ensure that the results can be replicated and the decay is in fact exponential.
Did you even try to figure this out yourself? Google gave me this, as well as a bunch more. <a class="postlink" href="http://wiki.answers.com/Q/How_do_you_find_the_half-life" onclick="window.open(this.href);return false;">http://wiki.answers.com/Q/How_do_you_find_the_half-life</a> Let's not waste people's time on easily found, run-of-the-mill shit.
Got a question for the electrical engineers. Looking at schematics, it's infuriating to trace the path of voltages through transistors. For example, when you key a radio, the keying circuit is grounded. This, among other things, will turn off a transistor in the receive circuitry. This then keeps a voltage from getting grounded, which turns on another transistor, which turns off another transistor, which turns off another transistor, which turns on another one, which finally does its job (shunting the receive signal to ground so you don't hear a receive signal in transmit). What the FUCK? Why all the ring-around-the-rosies bullshit? I see "No-yes-no-no-yes," which translates to "No." All you need is to hook the keying circuitry up to the transistor that mutes the signal. Make it a PNP transistor, so when the base is grounded, it turns on. Same exact thing, except with one transistor instead of five. But no, instead every single function of the radio goes through this sort of crap. Is there something that I'm missing, or do electrical engineers like making Rube Goldberg machines?
I'll try to ask this another way. If I'm being exceptionally stupid or wasting anyone's time then I apologize and I'll drop it. It's this step that I'm wondering about. When you're dealing with a half life of, say 50 billion years, don't you run into problems? Even if you wait a decade between measurements, there would hardly be any change. It seems like you'd either have to have a shitload of the material in order to see a substantial amount of decay, or have extremely sensitive instruments that can make very accurate measurements/detections. Unless I'm just missing something or not thinking about it the right way. Maybe I'm more curious about the tools and methods that are used, not simply the formulas and equations. I could just suck at google, but all that seems to give me are the formulas.
This is more of an "ask a doctor" question but here it goes: My niece, who is 2.5 years old, has a severe gluten allergy. The doctors and specialists my sister took her to were awful and my sister had to go through a serious of diet restrictions to isolate the problem herself. The doc's never even SUGGESTED that this might be the problem--they were more concerned with her being underweight (which was a symptom of something bigger). Her symptoms were rashes on the inside of her arms and back of her knees and debilitating and constant constipation for months, maybe even up to a year (instead of figuring out the problem, they told my sis to give her milk of magnesia and suppositories to help her poo...wtf?). She is also tiny, and this is what my question is about. She was of normal birth weight while she was breast feeding, but its almost like her growth stopped for awhile. She's a tiny little girl but has always been happy, energetic, and precocious. My sister is 5'6" and her husband is the same. Her husband is half Hawaiian and his mother, full Hawaiian, is like 5'1" or something, a very small lady. My sister also has a little boy who is just under a year younger than his sister and they were the same size for a long time. Now, my niece is slightly taller but they probably still weigh the same. I've googled it and can't seem to find anything about this. Does anyone know if a severe and virtually untreated food allergy could cause delays of growth in babies and toddlers? Or is it more likely that she is genetically predisposed to be about 4 and a half feet as an adult? I could supply pics as reference but I'm not comfortable with posting pictures of my sister's children online.
Seeing as nobody more qualified answered, I'll give it a shot. I am however only a medstudent, so use at your own risk. In dealing with children and food allergies, the best thing parents can do is introduce only one new food at a time, and hope that if there is a food allergy, it will manifest quickly enough so that the 'offending substance' can be identified. Well, as is sometimes the case, this doesn't work, and then the best thing to do is go through diet restrictions of common allergens (nuts, lactose, gluten...etc), while also considering other, more serious explanations for the symptoms, which I am glad your niece does not have. In terms of her size, there are 3 basic parameters pediatricians measure and plot on growth curves. Weight, height and head circumference. I am not entirely clear which one of those 3 was lagging, and by how much, and what the trend is. Pictures of your niece won't help, although I am sure she is cute, so you should totally post them. Babies are cute. Also - girls have different growth charts than boys, so comparing the size of the baby girl to the baby boy is like apples and pears. Anyway, to your question: Is she going to be tiny? The thing is, predicting future height of a 2.5 year old baby is as good as a random guess. Food allergies can definitely cause a temporary delay in growth as one of the symptoms, but that usually goes away after the allergy is treated and babies tend to catch up. I think you are asking whether her allergy may have permanent effects, and that is impossible to answer without knowing specifics. But - now you know what the cause of all her problems was, adjusted her diet, you should speak to her pediatrician about what her height, weight and head circumference are doing. If they are all trending appropriately, you do not need to worry. I think she'll be fine - she has basically 15 more years to grow. Hope this helps.
One of the major indicators of Celiac disease is being underweight. It always amuses me when gluten avoiding hippies who are clearly holding a few pounds talk about Celiac. There's a difference between not digesting gluten comfortably and Celiac Disease, IE the difference between a sensitive GI tract and and a major health impacting auto-immune disorder. A big part of Celiac is that you don't get proper nutrition from your diet because of the digestive issues - where a healthy and functional person's digestive tract would absorb all the things that make you grow and get fat, a Celiac sufferer eats and still becomes malnourished. It typically causes sufferers to either lose weight dramatically, or to be substantially under weight when diagnosed. I'm kind of staggered that at this point, where everyone thinks they have Celiac if they have any kind of gastric distress that can be alleviated by cutting down on bread, that it wouldn't be the first consideration for an underweight patient with known gluten issues. Given that Celiac is aggravated by diet, usually you don't see the malnourisment symptoms in younger kids. It's normally later onset and kicks in around a problematic diet. But it's not unheard of. I'm not a doctor, but Celiac disease impacts a couple of my family members, including a cousin who was massively underweight and dealing with constant annorexia/bulimia fears by the time they diagnosed her, despite eating like a white trash family at a buffet.
Scootah is right, there is a difference between Celiac disease and wheat allergy and gluten intolerance. Sounds like the niece "just" has the wheat allergy - rashes are more typical of the allergy. Plus, I assume she now officially carries the diagnosis - not that diagnosing something is always right, but Celiac is always considered in these cases, and I am assuming it was ruled out as a diagnosis, together with about a 100 other conditions that cause constipation and growth delay in babies. Please don't go freaking out that she has Celiac, see if she is improving on the gluten free diet. Like I said, allergies can cause temporary slowing of growth, but she should catch back up now that her problem is being addressed. This is a lot of assumptions, so really, it is best for your sister to sit down with the pediatrician at the next visit and ask to see the growth charts and ask to have them explained. It should take about 3 minutes and hopefully will give you a peace of mind. And remember, trends overtime are much more important than isolated points in time, so don't go on the CDC website and don't plot your niece's info from today and worry about a low percentile on the chart. Long way to say - just ask your doctor, they have the best info, and can answer your questions better than my guesses and assumptions from an internet post.
It is infuriating, but the logic and the math behind a sequence of 'yes' or 'no' is much easier to learn than the calculus that you would need to really understand PNP transistors or Op-Amps. If you're still having trouble, try modeling it in PSPICE first.
I don't think that she carries an official diagnosis of anything. The dumbass doctors and specialists had no answers and focused only on bandaid-ing the problem. She was on milk of magnesia twice DAILY which is NOT normal, and enemas on a multiple-weekly basis. She almost died because of burst intestines because she was so backed up and everything was compacting for so long. They had an Xray done to see what was going on in her intestines (looking for a possible physical blockage) and her lower intestines were literally swollen nearly to the point of bursting because of the severe compaction. My sister started taking out categories of food from her diet to isolate the problem herself. My niece just turned 3 and has been on a gluten free diet for about 6 months now. She is really good about asking if a new and unknown food has gluten in it and will refuse to eat it if it does. She was in pain for so long, she understands very well what gluten does and how it makes her feel. If my sister by accident gives her something with wheat it (usually she'll only get a couple bites before the mistake is realized), my niece will have a solid plug the next day to deal with. Anyways, ranting aside, my question was just whether this problem could affect her growth overall. I'm assuming that with a problem like this, her nutrition would have suffered as a result, and I know that humans put on a shitton of growth in their early years. I'm also not very sure that people are able to "catch up" in terms of growth. On the other hand, I'm not sure that the magnitude and time span of her problem would actually effect her growth overall. I have a pretty well rounded knowledge of medical and biological stuff, but I was wondering if anyone specifically knew about this subject. Thanks for the replies.
This is totally an aside, but bewildered check out this website: <a class="postlink" href="http://www.ratemds.com" onclick="window.open(this.href);return false;">http://www.ratemds.com</a> Search for a specialist in your area that has stellar reviews and DEMAND to be seen by him/her. Fight to get the referral, even if you have to wait to do it. I'm completely done with doctors. I refuse to go to see anyone before I check out that site because the medical establishment is too full of idiots. I know this sounds paranoid and bitchy, but I've had family members die due to medical malpractice in the last four years. The only way to avoid it is to be proactive, do some self-diagnosis (which you're doing), and then go to the best expert in the field. It saves so much heartache and uncertainty.
Thanks for the link. It simply infuriates me when I have a question and am actively looking for a solution and people tell me to ask my doctor. Doctors are people too, and they are not God's gift to man. Yes, they have a lot of medical knowledge and experience, but they are not infallible, and trusting 100% what they say is a path to hell. Not to say that I do not respect doctors, because I do, but they are not perfect and today they are expected to do a LOT. My and my family's health is more important to me than to blindly follow the words of one person (especially when their answers to questions have so far proved to be wrong).
There is a reason why none of the actual doctors or researchers on this board rushed to answer your question: Because, like most of medicine, it's "It depends". There is not enough info to answer it beyond that. This is why I also unintentionally angered you by recommended talking to your doc (or, if she/he is incompetent, transferring care to another one and then asking them. They should have all the relevant info to make the best educated guess.) Yes, malnutrition causes stunted growth. However, whether your niece was ever malnourished or vitamin deficient, and for how long, I have no idea. That is why I suggested looking at those growth curves. If she is constantly at the same percentage for all 3 parameters, she might just be a tiny girl. Yes, she was constipated and had in pain, but was she actually malabsorbing? Or maybe her height was constant and her weight was lagging. And it seems like she does not have a diagnosis, which is probably the most troublesome part. And even if she had a diagnosis, people are different and diseases have variable severity. Sorry if this has been extremely unhelpful. I'd probably focus on getting that little girl a good, caring doc, and giving her a good diet, rather than worrying about something that you cannot change, and might not even matter (her food and nutrition half a year ago). As a bio student, you can do a primary literature search on nutritional deficiencies in children on restricted diets, to make sure she is getting everything she needs after gluten was eliminated from her diet.
Has anyone here worked with Luminex Multiplex Assays before? The PI wants to run those more and more while the post-doc prefers ELISA. The post-doc prefers ELISA because of its repeatable precision and sensitivity whereas the PI prefers Luminex because of the ability to measure tons of cytokines at once. I don't have a horse in this race, just curious as to others experience in this area
On Saturday, I'm doing a Liquid Nitrogen branding day at my house. Since we'll have LN2 on hand anyway (10 liters was $150, 30 liters was $200, so we ordered extra...) I thought I'd do some fun LN2 stuff while we're going. As part of the safe materials handling stuff, we'll show off a safe finger dip and remove, and then freeze and smash a sausage. I've heard that you can freeze a banana and use it to hammer a nail, and that you can freeze an inflated balloon and then drop it so it smashes. I've seen a balloon deflate and then reinflate as the gas inside goes liquid and then heats up and goes back to gas - was thinking about doing something like that as well. I'd love to do a depth charge (LN2 in a coke bottle with a weight taped to the bottom of it, dropped into a metal rubbish bin or something about half full of water, tilted so that it's aimed away from the observers. LN2 heats and becomes gaseous and pressure in the bottle is apparently enough to explode the bottle and make an awesome depth charge style explosion) but cops would get called where I live so that's a no go. Any other cool back yard experiments worth trying? Maybe thinking of doing the instant ice cream thing, or the flower freeze and crumble thing - but would prefer something more fun.