Is it possible for a voltage multiplier to be used to provide both positive and negative voltage?

What I was wondering is it is possible to use a single voltage multiplier to provide a negative and positive voltage. Referring to this voltage doubler circuit, if you connect a capacitor to the top right node, and an ac source to that capacitor, can it produce dc voltage with the reverse polarity? I think it looks like it would because the diodes would be in the opposite polarity relative to the capacitor.

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What are the possible reasons to build a twin of the Eiffel Tower next to the original? [on hold]

I have been thinking of a “realistic” and near future scenario where an Emirati construction company manage to build a twin of the Eiffel Tower, on the Champ de Mars next to the original one. This twin is placed very close (I do not have any measurements for now) to the original, permitting the construction of a bridge between the first floors of both towers.

The twin is an exact copy of the original. The only differences would be in which company provided the antennae, where the steel were molded and who built it (the original was built by (if I remember correctly) Gustave Eiffel’s company in the late 1880’s, while the twin one was built by an Emirati company around the early 2030’s in which I set the scenario). The tower itself would cost the company around 28 million dollars according to some estimates if we were to build a twin of the tower today in real life (the original cost 38 million euros (however back then euro did not exist it was the franc))

But why would anyone build a twin of the Eiffel Tower in Paris next to the original? What are the possible reasons to do so in a modern contemporary world (similar to 2018)?

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Is it possible to add fluoride to my tap water?

I live in a city without fluoridated drinking water. Do I have any options for adding fluoride to my tap water?

I found countless results online for filters that can remove fluoride from tap water, but I would like to do the reverse and add fluoride to my water. I am asking the opposite of this question about removing fluoride.

Ideally, I would be able to install some sort of faucet-mounted filter (similar to the image below) that could add safe levels of fluoride to my tap water. Presumably this device would need to be refilled or replaced once in a while. Unfortunately, I suspect that this type of device probably does not exist.

Does a device like this exist? If not, do I have any other options for adding fluoride to my tap water?

I rent an apartment and I am not permitted to make permanent changes to my plumbing. I would prefer options that involve minimal / reversible modifications such as a faucet mounted filter (i.e. solutions that won’t upset landlord).

I am aware of the alternative methods for getting fluoride, such as:

  • Fluoride containing toothpaste
  • Fluoride containing mouthwash
  • Fluoride supplements

However, I am specifically asking about ways to add fluoride to tap water and I am not asking about these alternative methods.

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Delphi- Is it possible to style a firemonkey TOpenDialog created in a data module?

Is it possible to style a firemonkey TOpenDialog created in a data module?
If so how would I go about doing this?

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What are the possible reasons to build a twin of the Eiffel Tower next to the original?

I have been thinking of a “realistic” and near future scenario where an Emirati construction company manage to build a twin of the Eiffel Tower, on the Champ de Mars next to the original one. This twin is placed very close (I do not have any measurements for now) to the original, permitting the construction of a bridge between the first floors of both towers.

The twin is an exact copy of the original. The only differences would be in which company provided the antennae, where the steel were molded and who built it (the original was built by (if I remember correctly) Gustave Eiffel’s company in the late 1880’s, while the twin one was built by an Emirati company around the early 2030’s in which I set the scenario). The tower itself would cost the company around 28 million dollars according to some estimates if we were to build a twin of the tower today in real life (the original cost 38 million euros (however back then euro did not exist it was the franc))

But why would anyone build a twin of the Eiffel Tower in Paris next to the original? What are the possible reasons to do so in a modern contemporary world (similar to 2018)?

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Is it possible to migrate data into multiple translations of entities?

I’m running a multilingual migration of events (which are stored as nodes) that have keywords on them where there are keywords (stored as terms). The keywords should be stored in a multilingual tags vocabulary.

The source is a REST API, and what I have for the keyword data looks like this:

array (
 'id' => 'yso:p360',
 'alt_labels' => 
 array (
 ),
 'created_time' => '2014-06-23T11:37:29.198000Z',
 'last_modified_time' => '2014-06-23T11:37:29.198000Z',
 'aggregate' => false,
 'deprecated' => false,
 'n_events' => 11709,
 'data_source' => 'yso',
 'image' => NULL,
 'name' => 
 array (
   'fi' => 'kulttuuritapahtumat',
   'en' => 'cultural events',
   'sv' => 'kulturevenemang',
 ),
 '@id' => 'https://api.hel.fi/linkedevents/v1/keyword/yso:p360/',
 '@context' => 'http://schema.org',
 '@type' => 'Keyword',
)

Is there some way to use for example EntityGenerate to create all the translations of the tags when importing the original languages of the events that has these tags?

Note:

I would like to avoid migrating all the keywords first. We only import a subset of the events, and we are only interested in the keywords that are used by those events.

The normal way of D8 migrations with multilingual sources is to create a configuration for each translation. This doesn’t work in our case, as I chose to use entity_generate for the tags. If you have another suggestion, I am interested.

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is guest to guest audio possible with libvirt? (without networking) [on hold]

i have a gaming VM with libvirt and i use looking glass to monitor its screen. i have setup qemu to output the VMs sound to the host using pulseaudio. i was wondering it is possible to do this with another guest instead of the host. i know there is software that does this over the network, but my environment is very limited on bandwidth and i would prefer to not have to stream audio over the network.

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Is it possible to turn off external displays when I close the lid of my macbook?

By default, when I close the lid of my macbook, the external display becomes the primary. It is annoying because I have to plug out the cable and charger to turn it off but I’d like that whenever I close the lid of my macbook, it puts the macbook to sleep and turns off external display? Is it possible?

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Is it possible to fill 1×1 rectangle with 1×½, ½×⅓, ⅓×¼,…., 1/n×1/(n+1) rectangles?

Is it possible to fill $1times1$ rectangle with $1 times frac{1}{2}$, $frac{1}{2} times frac{1}{3}$, $frac{1}{3} times frac{1}{4}$.., $frac{1}{n}timesfrac{1}{n+1}$… rectangles?

This row converges, because when $n rightarrow infty$

$sum_{i=1}^infty(frac{1}{i}cdotfrac{1}{i+1}) = sum_{i=1}^infty (frac{1}{i} – frac{1}{i+1}) = 1 + O(frac{1}{n^2}) = 1$

As i thought, i should prove that if I can place $frac{1}{n}timesfrac{1}{n+1}$ rectangle, I can also place $frac{1}{n+1}timesfrac{1}{n+2}$ (following math induction principle). But here I’m facing a problem.
Also I want to know a filling algorithm, if it exists.

Update: As Kevin P. Costello mentioned this is an open problem.

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Is it possible to perform math between tables in Word

Thank you in advance for your assistance.
My need is twofold. I need to have a template word document that has a popup box or boxes asking several questions. The answers will be placed in particular areas and there is also math performed on several of the answers to place data in a separate table in word.
So Box A is hours app can be down.
box B is total time to evaluate
and Box c is the calculation using box A and B to get RTO for the application.

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