The cadmium sulfide cell, or cad cell, is part of the primary control system and is used to sense the presence of the oil burner flame. The cad cell assembly consists of the actual cell, a holder, and cord to connect the cell to the primary control. This detector is mounted in the air tube of the burner in such a way as to sight the flame.

The cad cell is made from a cadmium sulfide coated ceramic disk with a conductive grid over its surface. Electrodes are attached to this surface, and the cell is sealed in glass to protect it. The cad cell in darkness has a very high resistance to the flow of electrical current. Yet, in the presence of visible light, it has a very low resistance. For a properly adjusted burner, during operation, the cad cell resistance should be approximately 300-1000 ohms, but not more than 1600 ohms. A resistance above 1600 ohms signals a problem that should be corrected.

According to google searches, the Jinping Underground Laboratories are the "deepest" building or buildings constructed, reaching 7900 feet (2400 metre) below the surface.... However, the surface in question is a mountain. While that does classify as underground, it highlights a flaw in the question of the deepest underground building.

I can't seem to find the lowest building in the world though, or the deepest in relation to depth within the earth's crust.

What is the lowest point below sea level that we have built where a human can go? I imagine this is likely another laboratory. But where would a building of this description be?

"An N95 is more protective because it has a better face seal in general than a KN95 or a KF94," explains Aaron Collins, a mechanical engineer with a background in aerosols science. He's also known as the Mask Nerd because he's been testing hundreds of masks over the last year and a half. (You can explore a master spreadsheet of his results here.)

https://docs.google.com/spreadsheets/d/1M0mdNLpTWEGcluK6hh5LjjcFixwmOG853Ff45d3O-L0/edit?usp=sharing //

N95s are strapped to your head with a headband, which gives them a snug fit – and with masks, a tight fit is key to better protection. In its new guidance, the CDC notes that N95s and other NIOSH-approved respirators are the most protective options.

By contrast, both KF94s and KN95s attach with ear loops, which many people find more comfortable but don't seal quite as tightly to your face. //

N95s are made to U.S. government standards put out by the National Institute for Occupational Safety and Health and are rigorously tested, so they're a reliable choice. KF94 is a South Korean standard, and they're regulated by the Korean government. "Every [KF94] I've tested so far has been extremely high performing," Collins says.

KN95 is a Chinese respirator standard, but these respirators aren't strictly regulated by the Chinese government, according to both Collins and Anne Miller of Project N95, a nonprofit organization that connects consumers with legitimate masks and other PPE. While you can find some good KN95s (the ones made by Powecom have done well in tests), low-quality or outright fake KN95s have been a problem throughout the pandemic. //

Can I re-use an N95 or other respirator?
Yes, though Miller advises following the "brown bag decontamination method." Basically, if you need to wear a respirator all day for your job, at the end of the day, put it in a brown paper bag or hang it up in a cool, dry place. The idea is to let it rest for five days so any viral particles trapped on it can die off. Label the bags Monday mask, Tuesday mask, etc. The CDC advises reusing an N95 respirator no more than five times. (Health workers shouldn't reuse them.) Using this guideline, a rotation of just five respirators could last you 25 days, Miller notes.

What if you only don an N95 for a quick trip to the store every now and then? Then think about your respirator's total lifespan being about 40 hours of use, Miller advises – the equivalent of five eight-hour days. If the respirator is dirty or getting harder to breathe through, or the straps have gotten stretched out, it's time to toss it out.

1. Lists of all words
2. Word lists beginning with …
3. Word lists ending with …
4. Word lists containing
5. Word lists containing a sequence of letters
6. Word lists with a letter at position …

Recommended websites

• Visit WikWik.org - to search for words and build lists from
• Wiktionary's words.
• www.BestWordClub.com to play duplicate online scrabble.
• Ortograf.ws to look for words.
• 1word.ws to play with words, anagrams, suffixes, prefixes, etc.

Before there was English, or Latin, or even Greek, there was Proto-Sinaitic.

Considered the first alphabet ever used, the Proto-Sinaitic script was derived in Canaan, around the biblical Land of Israel. It was repurposed from Egyptian hieroglyphs that were commonly seen in the area (its name comes from Mount Sinai), and used to describe sounds instead of meanings.

As the first Semitic script, Proto-Sinaitic soon influenced other Semitic languages. It was the precursor to the Phoenician alphabet, which was used in the area of modern-day Lebanon and spread across the Mediterranean and became the basis for Arabic, Cyrillic, Hebrew, and of course, Greek. //

And the study of linguistics shows us why using Greek letters in English isn’t completely farfetched. This visualization from Matt Baker at UsefulCharts.com demonstrates how the modern Latin script used in English evolved from Greek, and other, alphabets.

OUI Lookup is a website that provides up-to-date information about MAC Addresses and OUI Vendors. Using the search bar, you can look for a OUI and find all vendors associated with the information you provided.

Energy in general is defined as the capacity for doing work. Power is the rate of doing work or the rate of using energy:
P=Work/t=Energy/t , where t is time.

Although casually the terms energy and power are often used interchangeably, we see that technically they have different meanings. The SI unit of energy and work (which are numerically the same) is the joule (J). A joule is the work done by a force of one newton for a distance of one meter. This unit is usually used in physics. Energy comes in many forms, such as heat, motion, gravitational, radiated solar power, and electrical. For different types of energy other physical units are also utilized. For example, the British Thermal Unit (Btu) is often used to measure the heat energy or compare fuels. One Btu is what's needed to heat one pound of water one degree F. The SI derived unit of power is watt (W). Watt is power required to produce or consume one joule of energy per second. This unit and its multiple kilowatt are usually utilized in ratings of various electric loads and sources of electricity, such as residential generators.

The operator of the Wayback Machine allows Wikipedia's users to check citations from books as well as the web. //

Wikipedia is the arbiter of truth on the internet. It's what settles arguments at bars. It supplies answers for the information snippets you see on your Google or Bing search results. It's the first stop for nearly everyone doing online research.

The reason people rely on Wikipedia, despite its imperfections, is that every claim is supposed to have citations. Any sentence that isn't backed up with a credible source risks being slapped with the dreaded "citation needed" label. Anyone can check out those citations to learn more about a subject, or verify that those sources actually say what a particular Wikipedia entry claims they do—that is, if you can find those sources.

It's easy enough when the sources are online. But many Wikipedia articles rely on good old-fashioned books. The entry on Martin Luther King Jr., for example, cites 66 different books. Until recently, if you wanted to verify that those books say what the article says they say, or if you just wanted to read the cited material, you'd need to track down a copy of the book.

Now, thanks to a new initiative by the Internet Archive, you can click the name of the book and see a two-page preview of the cited work, so long as the citation specifies a page number. You can also borrow a digital copy of the book, so long as no else has checked it out, for two weeks—much the same way you'd borrow a book from your local library. (Some groups of authors and publishers have challenged the archive's practice of allowing users to borrow unauthorized scanned books. The Internet Archive says it seeks to widen access to books in “balanced and respectful ways.”)

So far the Internet Archive has turned 130,000 references in Wikipedia entries in various languages into direct links to 50,000 books that the organization has scanned and made available to the public. The organization eventually hopes to allow users to view and borrow every book cited by Wikipedia, with the ultimate goal being to digitize every book ever published.

“Our goal is to be a library that’s useful and reachable by more people,” says Mark Graham, director of the Internet Archive's Wayback Machine service. //

Of course, the Internet Archive hasn’t scanned all the books cited by Wikipedia yet. It’s working hard to digitize collections from libraries around the world, along with donations from companies like Better World Books. Graham says the organization scans more than 1,000 books per day. But it has plenty more work to do.

Computer power supply units (PSU) deliver the power to the PC hardware via a number of cables with connectors. Their generic specifications for various desktop systems are defined in Intel's design guides, which used to be periodically revised. Their latest standard is PSU Design Guide rev.2.0 released on June 2018. This document combines the requirements for ATX12V v2.52 and its five variations. Note that some brand name manufacturers did not follow Intel guidelines and used non-standard pinouts. Also see the information on new ATX12VO standard.

Standard ATX power supplies typically have the main power connector P1, additional 12V connectors, as well as peripheral, floppy drive, serial ATA, and PCI Express® receptacles, which we will describe below.

This memo documents the fundamental truths of networking for the Internet community. This memo does not specify a standard, except in the sense that all standards must implicitly follow the fundamental truths. //

2. The Fundamental Truths

(1) It Has To Work.

(2) No matter how hard you push and no matter what the priority, you can't increase the speed of light.

(2a) (corollary). No matter how hard you try, you can't make a baby in much less than 9 months. Trying to speed this up might make it slower, but it won't make it happen any quicker.

(3) With sufficient thrust, pigs fly just fine. However, this is not necessarily a good idea. It is hard to be sure where they are going to land, and it could be dangerous sitting under them as they fly overhead.

(4) Some things in life can never be fully appreciated nor understood unless experienced firsthand. Some things in networking can never be fully understood by someone who neither builds commercial networking equipment nor runs an operational network.

(5) It is always possible to aglutenate multiple separate problems into a single complex interdependent solution. In most cases this is a bad idea.

(6) It is easier to move a problem around (for example, by moving the problem to a different part of the overall network architecture) than it is to solve it.

(6a) (corollary). It is always possible to add another level of indirection.

(7) It is always something

(7a) (corollary). Good, Fast, Cheap: Pick any two (you can't have all three).

(8) It is more complicated than you think.

(9) For all resources, whatever it is, you need more.

(9a) (corollary) Every networking problem always takes longer to solve than it seems like it should.

(10) One size never fits all.

(11) Every old idea will be proposed again with a different name and a different presentation, regardless of whether it works.

(11a) (corollary). See rule 6a.

(12) In protocol design, perfection has been reached not when there is nothing left to add, but when there is nothing left to take away.

Trends in Number of COVID-19 Cases and Deaths in the US Reported to CDC, by State/Territory
Reported to the CDC by State or Territory; Maps, charts, and data provided by CDC, updates Mon-Sat by 8 pm ET

Sebring, FL metro

Where are the differences between the stainless steel grades 1.4404 (316L) and 1.4571 (316Ti)? Please check the following analysis that highlights some of the main pros and cons of both material grades.

useful tools for the instrumentation engineer, such as the measurement of Normal, Current and Standard flow or the calculation of the amount of product that leaks through a pipe. We will gradually add more tools to this section. The results of all calculators are exportable in spreadsheet format.

Judging by the chronically empty shelves at gun shops and “out of stock” notices online, folks seem to be buying ammunition at unprecedented rates. Preppers stock up on things, like toilet paper, by the case. Ammo is no different. So when they buy, they look for bulk ammo deals. But how much ammo do you need? We have built this ammo calculator and written this article as a guide.

As a note, while I am listed as the author here, it’s actually the result of four minds coming together: myself, Steve Markwith, Aden Tate, and my behind-the-scenes web guy who took our collective thoughts and turned them into an online ammo calculator.

The calculator is below, but to make the most sense of your results – and this subject as a whole – it is important to read the article through. It explains our reasoning behind the formulas in the calculator and will help you determine whether they’re accurate for you and how to adjust your results up or down.

Common Oxygen Cylinder / Tank Size Chart:

LITERS  PSI HT  DIAM    LBS.

H (K) 7842 2000 55.0 9.0 120

There are standard size capsules that are named by numerical values. They are numbered: 000, 00, 0, 1, 2, 3, 4 and 5. These sizes are the same for all types of Gelatin, HPMC and Pullulan. The majority of capsule filling machinery are manufactured to be compatible with these standard sizes.

We have put together this guide to help you choose the best size for your needs.

Below is an interactive chart to help you choose the best fit. Click on each size to highlight the specifications of that size capsule.

Parabolic reflector antenna gain can be calculated from some simple formulas or equations, and the practical factors affecting the 'dish' antenna gain.

Touch temperature is based off the limitation of human skin. Human skin can bear some higher temperatures for brief periods of time before pain and cellular damage can set in. These two limitations, pain and damage, are the last things our users want to experience with our products. NASA put out an awesome summary of a new approach to touch temperature. NASA conducted some empirical data and research on previous studies to develop their own mathematical model of what temperatures are allowable for skin constant contact. Essentially, our pain threshold for heat depends on what area of the skin is heated, but in general that ranges between 42C (sensitive skin the chest area) to 45C (on our feet).

Contact Time

Another factor for determining the maximum touch temperature is how long a user might be in contact with the surface. Skin can handle higher temperatures for a few seconds before pain or skin damage occurs. Ecma International, a body responsible for creating standards for Information and Communication Technology and Consumer Electronics, has set some ergonomic limitations for skin contact time and temperature. The Standard ECMA-287 has a table the breaks down allowable temperatures based off use and the expected time of contact. //

Continuous hold ( < 8h) -- 43C
Short period touch ( < 10s) -- 55C metallic, 65C non-metallic
May be touched ( < 1s) -- 65C metallic, 85C non-metallic