Wikipedia:Reference desk/Archives/Miscellaneous/2021 February 17

= February 17 =

semi-trash water pump
Can anyone explain what a "semi-trash" water pump is? Is it just slightly better than one that is completely trash, or what? When it says 91 feet total head lift, does that mean it can pump water from ground level to 91 feet high? Not gonna buy it but have been following the madness in Houston (water and power are still out all over, people in apartment complex are portaging swimming pool water upstairs to flush their toilets) so started looking at this stuff. Thanks. 2602:24A:DE47:BB20:50DE:F402:42A6:A17D (talk) 20:35, 17 February 2021 (UTC)
 * added: they do have a full-trash one. I think maybe this has to do with the size of debris (rocks and stuff) that can pass through the pump along with the water, but that is just a guess.  Hmm. 2602:24A:DE47:BB20:50DE:F402:42A6:A17D (talk) 20:38, 17 February 2021 (UTC)


 * The first product overview says the ports can pass "soft solids up to 5/8 in. diameter", and the second "solids up to 1-1/4 in. diameter". --Lambiam 21:20, 17 February 2021 (UTC)


 * Yeah that's what made me guess about semi vs full trash. Thanks. 2602:24A:DE47:BB20:50DE:F402:42A6:A17D (talk) 22:31, 17 February 2021 (UTC)


 * The total head is the lift measured from the water level to the discharge, and yes, their 91 feet total head lift does mean that it can pump water up to 91 feet above the water level ... at 0 flow. Likewise, its maximum flow of 158 GPM is at 0 head.  This is stated explicitly in the manual in it's specification table on page 5:
 * Maximum Flow at 0’: 158 GPM
 * Maximum Head Lift at 0 Flow: 91 ft.
 * Note that the 91 ft maximum head lift implies a maximum discharge pressure of just under 40 psi.
 * Page 5 also include a Performance Curve ... which doesn't *quite* seem to match the specification, as it appears to suggest only 151 GPM at 0' but a 97' maximum head lift at 0 flow. -- ToE 00:48, 18 February 2021 (UTC)

Articles regarding smart cities impact on demographics of cities
Hello, I look for articles which describe what impact does a smart city has on a demographics of a population.

Thanks --Exx8 (talk) 22:08, 17 February 2021 (UTC)


 * Not an answer, but a comment. A study seeking to establish evidence of the effect will have to address two difficult issues. One is that there is no agreed measure for the smartness of a city, like city IQ. The second is that there may be a causal effect in the other direction, where the demographics drives political and economic decisions on the city's development. Therefore one should not expect much beyond anecdotal evidence of any impact. --Lambiam 08:00, 18 February 2021 (UTC)


 * The article smart city elucidates very little. I imagine it's something like an idea of good urban planning that uses plenty of internet-age technology. (It also seems like a good platform for me to run for city council on, since I couldn't be held accountable.) This question would be a good opportunity for someone who knows more to improve the article. Temerarius (talk) 08:18, 18 February 2021 (UTC)
 * Unless, ABF, a good platform for city council is all it really is. Elephas X. Maximus (talk) 01:09, 22 February 2021 (UTC)


 * In addition to the above, it's probably too early to measure demographic data. For one, smart cities is a very recent thing. For another, you'd need to compare before and after, requiring multiple censuses, which typically don't get done very frequently. On top of that, you'd have to control for other factors besides the "smartness". Matt Deres (talk) 20:59, 18 February 2021 (UTC)