Black is a color that results from the absence or complete absorption of visible light. It is an achromatic color, without chroma, like white and grey. It is often used symbolically or figuratively to represent darkness. Black and white have often been used to describe opposites such as good and evil, the Dark Ages versus the Age of Enlightenment, and night versus day. Since the Middle Ages, black has been the symbolic color of solemnity and authority, and for this reason it is still commonly worn by judges and magistrates.
Black was one of the first colors used by artists in Neolithic cave paintings. It was used in ancient Egypt and Greece as the color of the underworld. In the Roman Empire, it became the color of mourning, and over the centuries it was frequently associated with death, evil, witches, and magic. In the 14th century, it was worn by royalty, clergy, judges, and government officials in much of Europe. It became the color worn by English romantic poets, businessmen and statesmen in the 19th century, and a high fashion color in the 20th century. According to surveys in Europe and North America, it is the color most commonly associated with mourning, the end, secrets, magic, force, violence, fear, evil, and elegance.
Black is the most common ink color used for printing books, newspapers and documents, as it provides the highest contrast with white paper and thus is the easiest color to read. Similarly, black text on a white screen is the most common format used on computer screens. As of September 2019, the darkest material is made by MIT engineers from vertically aligned carbon nanotubes.
Cool commonly refers to:
- Cool, a moderately low temperature
- Cool (aesthetic), an aesthetic of attitude, behavior, and style
Cool or COOL may also refer to:
Dyson may refer to:
- Dyson (surname), people with the surname Dyson
- Dyson (company), a Singaporean multinational home appliances company founded by James Dyson
- Dyson (crater), a crater on the Moon
- Dyson (operating system), a Unix general-purpose operating system derived from Debian using the illumos kernel, libc, and SMF init system
- Dyson sphere, a hypothetical megastructure that completely encompasses a star and captures most or all of its power output
- Dyson tree, a hypothetical plant suggested by physicist Freeman Dyson
- Eufloria (formerly called Dyson), a video game based on the idea of Dyson trees
- USS Dyson (DD-572), a United States Navy destroyer in commission from 1942 to 1947
- NOAAS Oscar Dyson (R 224), an American fisheries and oceanographic research ship in commission in the National Oceanic and Atmospheric Administration since 2005
- Dysons, an Australian bus operator
- Dyson, a character in the Canadian television series Lost Girl
- The Charles H. Dyson School of Applied Economics and Management, often referred to as "Dyson"
Nickel is a chemical element; it has symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive, but large pieces are slow to react with air under standard conditions because a passivation layer of nickel oxide forms on the surface that prevents further corrosion. Even so, pure native nickel is found in Earth's crust only in tiny amounts, usually in ultramafic rocks, and in the interiors of larger nickel–iron meteorites that were not exposed to oxygen when outside Earth's atmosphere.
Meteoric nickel is found in combination with iron, a reflection of the origin of those elements as major end products of supernova nucleosynthesis. An iron–nickel mixture is thought to compose Earth's outer and inner cores.
Use of nickel (as natural meteoric nickel–iron alloy) has been traced as far back as 3500 BCE. Nickel was first isolated and classified as an element in 1751 by Axel Fredrik Cronstedt, who initially mistook the ore for a copper mineral, in the cobalt mines of Los, Hälsingland, Sweden. The element's name comes from a mischievous sprite of German miner mythology, Nickel (similar to Old Nick). Nickel minerals can be green, like copper ores, and were known as kupfernickel – Nickel's copper – because they produced no copper.
Although most nickel in the earth's crust exists as oxides, economically more important nickel ores are sulfides, especially pentlandite. Major production sites include Sulawesi, Indonesia, the Sudbury region, Canada (which is thought to be of meteoric origin), New Caledonia in the Pacific, Western Australia, and Norilsk, Russia.
Nickel is one of four elements (the others are iron, cobalt, and gadolinium) that are ferromagnetic at about room temperature. Alnico permanent magnets based partly on nickel are of intermediate strength between iron-based permanent magnets and rare-earth magnets. The metal is used chiefly in alloys and corrosion-resistant plating.
About 68% of world production is used in stainless steel. A further 10% is used for nickel-based and copper-based alloys, 9% for plating, 7% for alloy steels, 3% in foundries, and 4% in other applications such as in rechargeable batteries, including those in electric vehicles (EVs). Nickel is widely used in coins, though nickel-plated objects sometimes provoke nickel allergy. As a compound, nickel has a number of niche chemical manufacturing uses, such as a catalyst for hydrogenation, cathodes for rechargeable batteries, pigments and metal surface treatments. Nickel is an essential nutrient for some microorganisms and plants that have enzymes with nickel as an active site.
by Roger
Let me start by stating that I researched humidifiers more than any other product I have ever purchased. My wife and I live in Southern California, it gets dry, add to that the terrible air quality with fires and pollution, our AC drys out what little humidity is left in the house, you can see where I am going.
We looked at every Air purifier/humidifier available regardless of cost and nothing came close to this Dyson, yes this is expensive but it is a high quality item that should last for years.
It is important to remember that no home humidifier will maintain an exact humidity, it will rise and fall throughout the day depending on a multitude of conditions but in my experience this machine does the best job overall, it maintains at least 30% humidity and takes most everything out of the air.
We only use distilled water and we keep it clean, very important because our city water is the hardest water ever, nothing kills a humidifier like hard water. Dyson states you can use tap water but I don’t want to take that chance. Take no notice of any negative reviews, I consider myself to be the most critical person with this type of home product, it helps if you own other Dyson products and you will appreciate what I mean.
It has run perfectly and looks great, we love being able to control it with the Dyson app, we are perfectly satisfied and happy with this product.
by Dan
Been using the air filter / humidifier for about 3 weeks now and overall I’m thoroughly impressed. The first unit I purchased actually had a sensor issue that prevented the humidifier from functioning. Customer service was quick to diagnose the issue and I had a replacement shipped out. A frustrating first impression to say the least.
However, once I got the replacement it was smooth sailing. The unit is sleek and I like the look (though I would have preferred a different color, but none were available). It is powerful, quiet, and smooth in all aspects of its operation. The remote is compact, with a simple intuitive layout. The app is responsive, doesn’t crash, and includes all the features I was looking for: scheduling, and real time air quality and humidity readings. The water reservoir is a little weirdly shaped, and occasionally the filter covers take a bit of finesse to align before they click in, but these concerns are minor.
The only real con I’ve found is the price, which is quite steep if you’re just looking for just an air purifier or humidifier function – there are options 5-10 times cheaper. However, Dyson has created a sleek, functional product line and ecosystem that definitely delivers if you can afford it.
HomeKit integration would have been nice, but it looks like there are bridges out there that can handle that.
by Andrew
Our home, at over 7,000 feet elevation in southwest Colorado, winters can be long. Our wood stove is going most of the time. The Dyson is doing a good job of filtering out the closed-in air from opening and closing the wood stove and cooking odors. I like being able to check on it’s status and to make adjustments off of my I-Pad.
by Duell
Love this product-wish I could afford another one. Was easy to set up. Works great!
by Mira
The assembly was really easy and I love how quiet it is. I also use the app all the time, it’s super-helpful with a lot of useful information.
by Eileen
My wife had tried every “recommended” machine with little or no results to her health and or they required endless cleaning with burdensome technical language if anything went wrong, which was frequently.
The Dyson product was easy to set up and operated….very user friendly The cleaning (after 2 weeks) was easy by comparison. Most importantly my wife had immediate positive results (the unit is in a dry high elevation climate) to her hearlth (breathing, energy, nasal issues).
by Stevie
I happened to buy this Dyson product about a week prior to the devastating wildfires in California which have severely compromised our air quality. My readings on my Dyson app indicated that my machine was detecting an “extremely high level of potentially harmful microscopic particles and VOCs”. Running my Dyson as suggested returned my air quality to a “good” although outdoors the air remained very poor.
by Julie
I just can’t say enough about this machine! It’s a splurge….however, you are getting a purifier, fan and humidifier all in 1 unit. I sold our pedestal fan, large humidifier and air purifier. Now we have just 1 sleek styled unit that hardly takes up any room. We have 2 dachshunds and although they are clean, they can smell at times when coming in wet. This unit always takes out any odors. A few years ago I purchased the Dyson Pure Cool TP04 for our bedroom. I have run this unit 24 hours a day, 365 days a year. It still runs perfect. My favorite thing about these Dyson fan units are how easy they are to set up and use. Plus, there are several videos online to refer to. You can operate it thru the app on your phone (which I prefer) or there is a magnetic remote control that sits on top of the fan. Best of all, when the UPS person delivered it – he said I’ve been looking at this box on my delivery stops and it looks like an awesome unit!