Nevermoor - The Trials of Morrigan Crow Book 1 audiobook by Gemma Whelan. See rules 1 and 2 for addressing spoilers in titles. Barkley (The Puppy Place 66) audiobook by Ellen Miles, Eliza Foss. Instructions on using spoilers in comments:
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“We can have multiple people looking for different locators,” Larkin said. Once an order is complete, the DartTag is sent to a new zone in preparation for the next order. They now move orders to the most appropriate location in the warehouse without concern over whether others will find it. To find each staging area, pickers consult one of several large monitors placed strategically throughout the warehouse or handheld devices and bring items to the right location. Oracle specifies the staging location associated with a UWB tag where pickers should deliver items for a specific order. The warehouse assigns a DartTag to each order and places it in a staging area. To improve communication regarding staging areas, Zebra leveraged its Dart Ultra-Wideband (UWB) RTLS hardware and Visibility Server Software (VSS). Already, the warehouse had the Zebra WhereNet ISO/24730-2 and Ultra Wideband (UWB) infrastructure in place. RTLS provides precise positioning solutions with active RFID for real-time identification and tracking of objects and people. Zebra turned to its own real-time locating systems (RTLS) technology to improve communication and efficiency at the Vernon Hills distribution center. Real-Time, Accurate Data for Staging Orders. Goods accumulated in the narrow aisles, blocking picking, creating a safety hazard, and slowing order completion by up to 15 minutes – several times a day. Yet, they had no way to notify the shipping staff when it was time to remove items from the aisle. Team members would stage completed reconfigurations in the aisles until the finished goods were moved to the shipping area. Reconfigurations refer to customizations of printers and other accessories for specific customer needs. Pairing reconfigured products with the rest of orders presented another challenge. “It was taking one to two minutes to find where to put the material we had just picked.” “It was very difficult to locate individual items to pair up orders,” said Daniel Larkin, Warehouse Control Board Manager. At times, they would relocate an order multiple times before it was complete and pickers frequently had to search through products already in the staging area to complete an order. However, in Oracle, orders are “blind” to the size of the area required for staging. “With our Oracle implementation we improved our operational efficiency and capabilities from a business process perspective, but we still lacked visibility into the actual actions taking place in our warehouse.” Ashley Ford, Vice President & General Manager – North America Items remain in a staging area until the entire order is complete. When pickers move products from the warehouse to staging areas, they often need to combine items with other picked goods before they are ready for shipment. With the move to Oracle, Zebra had to change its process for consolidating orders. “With our Oracle implementation we improved our operational efficiency and capabilities from a business process perspective, but we still lacked visibility into the actual actions taking place in our warehouse,” said Ashley Ford, Vice President & General Manager – North America. With the deployment, Zebra identified opportunities in its North American distribution center to enhance operations. As part of that, the company deployed Oracle, allowing it to connect many stand-alone systems into one and drive operational efficiencies. Zebra’s North American operations recently initiated a multi-year program focused on systems and processes to support its overall business transformation. The location serves customers and partners across North America and Latin America. From its 72,000 square foot distribution center in Vernon Hills, Illinois, Zebra Technologies processes and picks more than 16,000 items comprising printers, RTLS equipment and accessories every day. start_date = '' end_date = '' # tickers tickers = # User pandas_ to load the desired data. Code Download of Data and CVaR Optimization # We download closing prices for the period to. Small Cap should be the most risky investment, but due to the low correlation between bond returns and Small Cap stock returns then we can achieve diversification benefits from including it which more than offset its component risk. Interestingly, we can see that our most risk-averse portfolio consist of BOTH bonds and Small Cap. Small Cap on average returns higher profits than Large Cap, but also contributes with an additional risk to the portfolio, due to illiquidity, poor capitalisation etc. This all makes perfect sense according to the economic theory, as bonds should provide the most defensive allocation. In the beginning, we primarily allocate to the US Large Cap equity, which then changes to the US Small Cap towards the more risky portfolios. As we increase the risk level, the equity allocation increases as well. We see that the most risk-averse portfolio consists primarily of bonds with a minor allocation to Small Cap stocks. Let’s now observe the portfolio allocation for each frontier point. In the beginning, we have a large increase in return when allowing for a bit more risk, while in the end we gain nearly no increase in expected returns for the same increase in risk. We can observe that our efficient frontier looks similar to what we would expect. I use the brilliant Python library PuLP to formulate a linear optimization model, and iteratively find the optimal portfolio for different risk aversions. To illustrate the application of CVaR in a portfolio setting, I download data from Yahoo on 5 ETFs, tracking four equity markets and one aggregated bond market respectively. This effectively leads to the maximization of the Sharpe ratio in the mean-variance setting, and the STAR ratio for CVaR. This is represented by the shape of the efficient frontier.Īs risk and return are not linearly dependant, it makes sense to consider the marginal increase in expected return when increasing the risk. Hence, increasing the riskiness of a portfolio will not nessecarily result in an equal increase in expected returns. There exist a quadratic relationship between risk and expected return. If we introduce a risk aversion coefficient, then the mean-CVaR portfolio optimisation model can be written: Similar to the mean-variance model, we can construct a portfolio, which maximizes the expected return for some level of risk (in this case, expressed using CVaR). This means that we can easily integrate it in a portfolio optimization framework. So, Conditional Value at Risk is a superior measure of risk and can be mathematically expressed as defined asĬonditional Value at Risk is not only convinient as it better identifies the tail risk than VaR, but it also holds desirable numerical properties such as linearity. Intuitively, this does not make any sense and breaks the reason for diversifying a portfolio. In some special cases for the VaR metric, this statement becomes violated and it becomes mathematically possible to obtain a risk reduction by dividing a portfolio into two sub-portfolios. Here, subadditivity means that a portfolio’s risk cannot exceed the combined risks of the individual positions. In addition, the VaR measurement fails to be risk-coherent as it lacks subadditivity and convexity. the nessesity to assume normally distributed returns. The introduction of CVaR is justified by many numerical problems of using VaR in practice, e.g. The measure is a natural extention of the Value at Risk (VaR) proposed in the Basel II Accord. The metric is computed as an average of the % worst case scenarios over some time horizon. This post is about how to use the Conditional Value at Risk measure in a portfolio optimization framework.Ĭonditional Value at Risk (CVaR) is a popular risk measure among professional investors used to quantify the extent of potential big losses. For example, if a portfolio value drops by 10% then we would need to regain 11.1% to neutralize this loss. Here, the mitigration of large losses is of paramount importance, as gains and losses are asymmetric by nature. Constructing a portfolio with high risk-adjusted returns is all about risk management. He soon became a cocoa bean exporter, in an industry that he says is 20 years behind the coffee trade in terms of sophistication and efficiency. "Four months later I was in the Amazon," he says, buying cacao beans from subsistence farmers. Askinosie, a former criminal defense attorney, decided to try making chocolate from scratch after getting into baking as a midlife hobby. A 3-ounce Askinosie bar, made from beans bought from farmers in San Jose del Tambo, Ecuador, will set you back $8. That financial transparency pays off, Askinosie says, because farmers are motivated to test and perfect their drying and fermentation methods, which have a huge influence on chocolate flavor.īut making chocolate that way isn't cheap. Then I go back with my financial statements, translated in whatever language they need, and profit-share with them." "I actually go source these beans myself on four continents, directly with farmers," says Shawn Askinosie, founder of Askinosie Chocolate, based in Springfield, Mo. Many also hope that the farm-to-bar pipeline will make for more ethical, sustainable production in an industry with a long history of exploitation. Ring, a former Silicon Valley entrepreneur who co-founded the social networking site Plaxo, says: "The beans are the stars of the show."īy controlling the chocolate-making process from the farm to the bar, bean-to-bar chocolate entrepreneurs say they can create better chocolate - chocolate that preserves the beans' distinctive flavors. They are meant to be tasted and compared, akin to a wine tasting or coffee cupping. The bars are simple, made with just cocoa beans and sugar. Thus the factory in a high-traffic area of downtown San Francisco, with a small store and cafe up front that lure customers in to see the whirring machines in the factory beyond.ĭandelion imports chocolate from individual farms in the Dominican Republic, Venezuela and Madagascar. As part of the growing bean-to-bar chocolate movement, he wants to tell that story. "Chocolate is one food where everyone is familiar with it, but it has this untold story," Ring says. They're sequestered in a sealed room that vents outside. The grassy, acrid smell of fermented cacao beans is even less alluring. Just-ground cocoa beans exude an acidic tang that fades in a day or two, to be replaced by that classic chocolate aroma. And it's not just the sweet perfume of freshly tempered chocolate. The floor plan may be modest, but the olfactory output is huge. That lush chocolate scent is wafting from a new factory that's smaller than many two-bedroom apartments. "A lot of people walk in, 'Oh, my gosh, the smell!" says Cameron Ring, co-owner of Dandelion Chocolate. The story of chef Grant Achatz is fascinating and learning about it makes you truly appreciate what he’s done with this restaurant.If you're looking to buy chocolate in San Francisco this Valentine's Day, just follow your nose down Valencia Street. It was featured in an episode of Chef’s Table on Netflix, which you must watch if you haven’t already. Chuckles took me out to the incredible Alinea, the only three Michelin star restaurant in Chicago. Our evening was the highlight of our entire trip. It would have been a better experience on a warm spring day, but unfortunately we arrived during the midst of a polar vortex that extended well into April, so it was pretty breezy on the boat deck. Well, we did it! It was actually quite an interesting 1.5 hour boat ride along the Chicago River with a guide telling us about the city’s various architectural landmarks. This is apparently a ‘top ten’ tour in Chicago and according to many TripAdvisor reviews, is a must-do for Chicago visitors. A post shared by Jessica | I’ve Bean Eating the afternoon, we went on the well-hyped Chicago Architecture Foundation river cruise. Meanwhile, the best PC cleaner software features a suite of clean up tools bundled together.Īnd it’s not just PCs that suffer from duplicates cluttering up storage. More specialist programs can help you shred files or fix 100% disk usage and other specific issues. If you just want to free up disk space quickly, some duplicate file finders can delete all dupes on your device automatically. The best duplicate file finder depends on your particular requirements and tastes. Here are the best duplicate file finders for Windows: Let’s take a look at the best duplicate file finders for Windows: Which is the best duplicate file finder? Pesky files you think have been deleted may still be hanging around, so see how to permanently delete files and make sure they’re gone for good.ĭeleting duplicate files and other junk helps streamline your machine. Defragging your hard drive tidies up your disk configuration, while deleting temporary files can free up gigabytes of storage. Check for duplicate files every few months, and don’t forget to password protect files and folders on Windows that you want to keep safe.ĭeleting duplicates is a good place to start, but there are other ways to clean up your PC too. Windows 10 doesn’t have a built-in duplicate file finder, so getting a third-party program to find duplicate files will save you a lot of frustration, while reclaiming valuable disk space.Īfter choosing the Windows duplicate file finder that’s right for you, all you need to do is run a scan to identify unnecessary duplicates and get rid of any junk you don’t need. Over time, your computer gets clogged up with redundant data and duplicate files that slow down your system. It’s easy to find several copies of the same file littering various corners of your hard drive. 73870388041 Logo Ameba Icon Security Icon Security White Icon Privacy Icon Performance Icon Privacy Icon Security Icon Performance Icons/45/01 Security/Other-Threats Icons / 32 / Bloatware removal Icons / 32 / Registry Cleaner Icons / 32 / CleanUp Icons / Feature / 32 / Mac Icons / 32 / Browser cleanup Icons/32/01 Security/Malware Icons/32/01 Security/Viruses Icons/32/01 Security/Other-Threats Icons/32/01 Security/phishing Icons/32/01 Security/Scams Icons/32/01 Security/hacking Icons/32/01 Security/Security-tips Icons/32/01 Privacy/Privacy-tips Icons/32/01 Performance/Software Icons/32/01 Privacy/Identity-Protection Icons/32/01 Privacy/Digital-life Icons/32/01 Performance/Performance-tips Icons/32/01 Security/Passwords Icons/32/01 Security/Ransomware Icons/32/01 Security/Business Icons/32/02 Privacy/Browser Icons/32/02 Privacy/IP adress Icons/32/02 Privacy/VPN Icons/32/02 Privacy/Proxy Icons/32/02 Privacy/Streaming Icons/32/03 Performance/Celaning Icons/32/03 Performance/Drivers Icons/32/03 Performance/Gaming Icons/32/03 Performance/Hardware Icons/32/03 Performance/Speed Icons / 32 / Bloatware removal Icons / 32 / Registry Cleaner Win Icons / 32 / CleanUp Icons / Feature / 32 / Mac Icons / 32 / Browser cleanup Icons/60/02 Privacy/02_Privacy Icons/60/01 Security/01_Security Icons/60/03 Performance/03_Performance Icons/45/01 Security/phishing Icons/45/01 Security/Scams Icons/45/01 Security/hacking Icons/45/01 Security/Security-tips Icons/45/01 Privacy/Privacy-tips Icons/45/01 Performance/Software Icons/45/01 Privacy/Identity-Protection Icons/45/01 Privacy/Digital-life Icons/45/01 Performance/Performance-tips Icons/80/01 Security/phishing Icons/80/01 Security/Scams Icons/80/01 Security/hacking Icons/80/01 Security/Security-tips Icons/80/01 Privacy/Privacy-tips Icons/80/01 Performance/Software Icons/80/01 Privacy/Identity-Protection Icons/80/01 Privacy/Digital-life Icons/80/01 Performance/Performance-tips Icons/80/01 Security/IoT Icons/80/01 Security/Malware Icons/80/01 Security/Passwords Icons/80/01 Security/Ransomware Icons/80/01 Security/Viruses Icons/80/01 Security/Other-Threats Icons/80/03 Security/Business Icons/80/02 Privacy/Browser Icons/80/02 Privacy/IP adress Icons/80/02 Privacy/VPN Icons/80/02 Privacy/Proxy Icons/80/02 Privacy/Streaming Icons/80/03 Performance/Celaning Icons/80/03 Performance/Drivers Icons/80/03 Performance/Gaming Icons/80/03 Performance/Hardware Icons/80/03 Performance/Speed Icons/80/03 Performance/03_Performance Icons/80/02 Privacy/02_Privacy The formula of Moment of Inertia is expressed as I m i r i2. The integration techniques demonstrated can be used to find the. The formula for the moment of inertia is the sum of the product of mass of each particle with the square of its distance from the axis of the rotation. The following table, includes the formulas, one can use to calculate the main mechanical properties of the circular section. In following sections we will use the integral definitions of moment of inertia (10.1.3) to find the moments of inertia of five common shapes: rectangle, triangle, circle, semi-circle, and quarter-circle with respect to a specified axis. For a circular section, substitution to the above expression gives the following radius of gyration, around any axis, through center:Ĭircle is the shape with minimum radius of gyration, compared to any other section with the same area A. Small radius indicates a more compact cross-section. The second polar moment of area, also known (incorrectly, colloquially) as 'polar moment of inertia' or even 'moment of inertia', is a quantity used to describe resistance to torsional deformation ( deflection ), in objects (or segments of an object) with an invariant cross-section and no significant warping or out. It describes how far from centroid the area is distributed. An annulus of inner radius r 1 and moment of inertia for cirular cross section formula questions. The dimensions of radius of gyration are. Polar Moment Of Inertia - Definition, Formula, Uses. Where I the moment of inertia of the cross-section around the same axis and A its area. To obtain the scalar moments of inertia I above, the tensor moment of inertia I is projected along some axis defined by a unit vector n according to the formula:, where the dots indicate tensor contraction and the Einstein summation convention is used. To calculate the polar moment of inertia J of a circle of diameter D 5 cm, use the formula: J D/32 (5 cm)/32 61.36 cm. Radius of gyration R_g of any cross-section, relative to an axis, is given by the general formula: The method is demonstrated in the following examples. This list of moment of inertia tensors is given for principal axes of each object. The area A and the perimeter P, of a circular cross-section, having radius R, can be found with the next two formulas: The formula for the moment of inertia uses distances from an axis, or, if you are using the fancier tensor formula, coordinates relative to an origin. Yellow strip: release when the countdown timer has a 5 in any position.White strip: release when the countdown timer has a 1 in any position.Blue strip: release when the countdown timer has a 4 in any position.Based on its color, you must release the button at a specific point in time: If you start holding the button down, a colored strip will light up on the right side of the module. If none of the above apply, hold the button and refer to "Releasing a Held Button".If the button is red and the button says "Hold", press and immediately release the button.If the button is yellow, hold the button and refer to "Releasing a Held Button".If there are more than 2 batteries on the bomb and there is a lit indicator with label FRK, press and immediately release the button.If the button is white and there is a lit indicator with label CAR, hold the button and refer to "Releasing a Held Button".If there is more than 1 battery on the bomb and the button says "Detonate", press and immediately release the button.If the button is blue and the button says "Abort", hold the button and refer to "Releasing a Held Button". See Appendix B for battery identification reference.įollow these rules in the order they are listed. See Appendix A for indicator identification reference. That’s the kind of thinking that gets people exploded. You might think that a button telling you to press it is pretty straightforward. Otherwise, if there are no red wires, cut the last wire. Otherwise, if there is exactly one yellow wire and there is more than one white wire, cut the fourth wire. If there are no yellow wires and the last digit of the serial number is odd, cut the third wire. Otherwise, if there are no black wires, cut the second wire. Otherwise, if there is exactly one red wire and there is more than one yellow wire, cut the first wire. If the last wire is black and the last digit of the serial number is odd, cut the fourth wire. Otherwise, if there is more than one yellow wire, cut the last wire. Otherwise, if there is exactly one blue wire, cut the first wire. Otherwise, if the last wire is yellow and there are no red wires, cut the first wire. If there is more than one red wire and the last digit of the serial number is odd, cut the last red wire. Otherwise, if there is more than one blue wire, cut the last blue wire. Otherwise, if the last wire is white, cut the last wire. If there are no red wires, cut the second wire. Wire ordering begins with the first on the top.Only the one correct wire needs to be cut to disarm the module.A wire module can have 3-6 wires on it.Wires are the lifeblood of electronics! Wait, no, electricity is the lifeblood. So CleanMyMac X can do it for you, and uninstall the app with all its remains. Finding all the app leftovers manually can also be a challenge - their many locations are almost impossible to detect. Sometimes, it can be hard to get rid of an app completely. How much of a difference these things will make depends largely on the age of your Mac and how you use it, but it’s a useful little selection anyway. Simply choose the scripts you want to use, then click the Run button. The app allows you to clean your memory and optimize the operation of your Mac by running maintenance scripts, closing resource-intensive programs, terminating hung-up programs, freeing up RAM, and so on. This basically mirrors what you can already do in macOS’s System Preferences but with more control and a greater list of processes, you can prevent from starting with your Mac. You can manage apps as well as launch agents, which run in the background. This part of CleanMyMac is all about taking control of what’s running on your Mac when it starts. Otherwise, you might not find it that useful. If you use a lot of these apps and you want to stay private, this tool could save you some time. Plus you can delete your chat data from apps like Skype. In the Privacy section, you can clear out browser histories, auto-fill data, and other information your web browsers collect about your online activity. There isn’t a way to schedule scans, but the real-time protection should be all you need. As well as searching for viruses, worms and other such threats, it will also find and remove potentially unwanted applications (PUAs), which can include adware, pirated software and other software that might not be trustworthy. If you need antivirus, then you’ll be pleased to learn CleanMyMac offers real-time protection, as well as on-demand scans. It’s much quicker to use a keyboard shortcut to empty your trash than it is to open up a separate app. This isn’t a hugely useful feature, though, to be honest. It also looks for trashed files in other places on your Mac, including in Mail and your photo library. Trash BinsĬleanMyMac’s Trash Bins tool doesn’t just empty your normal trash. Also, it won’t delete files if you’ve modified them, which is handy, as you’re likely to want to keep those. But don’t worry: the CleanMyMac will only remove local file copies, while the originals stay safely stored in your inbox. With a single click, you can then delete them. The Mail Attachments feature scans your Mac for email attachments that have been downloaded onto your system disk. That means you can clear up disk space on your Mac in no time at all. As with most Mac cleaning tools, this is much faster than finding these files manually. This includes system and user caches, unused disk images, log files, downloads, and more. Using the System Junk scanner, you can find all kinds of unnecessary data on your Mac. These are all split into five categories: Cleanup, Protection, Speed, Applications, and Files. And it has tools to optimize your Mac’s performance too. It can quickly scan for and remove a variety of different data, including caches, log files, and attachments. CleanMyMac X features overviewĪlthough it does offer some basic security and privacy tools, CleanMyMac X is primarily a cleaning and optimization app. In this review, we look at all of CleanMyMac’s different features, and how they can help your Mac to run more effectively. It’s available on subscription, but you can also pay for a lifetime license - though this is notably more expensive. Founded by the Ukrainian developer MacPaw in 2008, it offers a large number of tools for cleaning, optimizing, and protecting Macs. CleanMyMac is one of the most popular Mac-cleaning apps around at the moment. For modern houses and apartments with large windows and limited wall space, a drop down screen in front of the window enables great viewing of TV, movies and sports. It also provides a quick-connect power plug and Velcro-fastened nylon straps for secure installation and simple but fast removal. You can turn any wall into a life-sized window to another world. At just over three inches high and nearly 14 inches long, the Hideaway combines a 150-watt amplifier and an 8-inch subwoofer to add thumping bass to any vehicle from the tightest locations. And since the projector is mounted in front rather than behind the viewers, there are no issues with shadows or obstructions from ceiling lights or fans. It is the ideal projector for large display sizes in small spaces, as well as locations with high ceilings. The unique form factor of the VPL-VZ1000ES opens up a whole new set of usage scenarios. Sony's advanced SXRD™ panels coupled with the laser light engine produce high dynamic contrast, enhancing the highlights and lowlights of HDR content. Despite its compact size, the VPL-VZ1000ES's Z-Phosphor™ laser light source generates 2,500 lumens of color light output, 25% brighter than VPL-GTZ1. This is over 40% smaller than the currently available Sony VPL-GTZ1 ultra-short throw projector. The VPL-VZ1000ES is approximately 36 x 20 x 9 inches in size (WxDxH, 925 x 494 x 219mm) and weighs about 77 lbs (35 kg), making it small and light enough to complement virtually any décor. "Now, it's possible to project a 4K HDR quality 100" or even 120" display in your family room without the need for a dedicated media room." Sony enables the best of both worlds with this new generation of ultra-short throw projectors," said Mike Fasulo, President and COO of Sony Electronics. Hideaway (1995) Seven Years in Tibet (1997) Swept from the Sea (1998) Desperate Measures (1998) 3 Ninjas: High Noon at Mega Mountain (1998. Everyone wants a larger screen, but not everyone can find the space for it. Full open matte variant with corporate text as seen on the Sony Pictures Museum site (as of November 2015) 19931999 Tenth Anniversary promo logo. "The VPL-VZ1000ES ultra-short throw projector is a real game changer. It's a projector designed to live in the living room, not hide away in a media room. It is now possible to have an immersive viewing experience in any room-with no limits on the layout of your home. signature technologies including a hide-away Sony television from Nexus21. Sony Pictures The hub for your favourite movies and TV shows. Sony's latest brainchild is a High Dynamic Range (HDR) compatible, native 4K resolution laser light source projector that can be positioned as little as 6 inches away from the wall, yet command the room with a 100 inch image (measured diagonally in 16:9.) When powered off, the compact and elegant VPL-VZ1000ES virtually disappears into the décor. Sony introduced a new video projector thats very sleek and thin looking. Sony and the Environment How we’re reducing our eco-footprint through energy efficiency and recycling initiatives. 4, 2017 /PRNewswire/ - (CES, Booth #17300) - Sony Electronics announced today the VPL-VZ1000ES Ultra-Short Throw 4K HDR Home Theater Projector designed to integrate easily into one's existing home and lifestyle. He also noted the similarity of ozone smell to the smell of phosphorus, and in 1844 proved that the product of reaction of white phosphorus with air is identical. įor this reason, Schönbein is generally credited with the discovery of ozone. In 1839, he succeeded in isolating the gaseous chemical and named it "ozone", from the Greek word ozein ( ὄζειν) meaning "to smell". Ī half century later, Christian Friedrich Schönbein noticed the same pungent odour and recognized it as the smell often following a bolt of lightning. In 1785, Dutch chemist Martinus van Marum was conducting experiments involving electrical sparking above water when he noticed an unusual smell, which he attributed to the electrical reactions, failing to realize that he had in fact created ozone. History Christian Friedrich Schönbein (18 October 1799 – 29 August 1868) A prototype ozonometer built by John Smyth in 1865 Care should be taken to avoid confusing the name of the group for the context-specific name for the ozone given above. Trioxidanediyl (or ozonide) is used, non-systematically, to refer to the substituent group (-OOO-). In an even more specific context, this can also name the non-radical singlet ground state, whereas the diradical state is named trioxidanediyl. By default, these names pay no regard to the radicality of the ozone molecule. In appropriate contexts, ozone can be viewed as trioxidane with two hydrogen atoms removed, and as such, trioxidanylidene may be used as a systematic name, according to substitutive nomenclature. The name ozone derives from ozein (ὄζειν), the Greek neuter present participle for smell, referring to ozone's distinctive smell. The systematic names 2λ 4-trioxidiene and catena-trioxygen, valid IUPAC names, are constructed according to the substitutive and additive nomenclatures, respectively. The trivial name ozone is the most commonly used and preferred IUPAC name. While this makes ozone a potent respiratory hazard and pollutant near ground level, a higher concentration in the ozone layer (from two to eight ppm) is beneficial, preventing damaging UV light from reaching the Earth's surface. This same high oxidizing potential, however, causes ozone to damage mucous and respiratory tissues in animals, and also tissues in plants, above concentrations of about 0.1 ppm. Ozone is a powerful oxidant (far more so than dioxygen) and has many industrial and consumer applications related to oxidation. It is therefore used commercially only in low concentrations. Ozone's instability with regard to more common dioxygen is such that both concentrated gas and liquid ozone may decompose explosively at elevated temperatures, physical shock, or fast warming to the boiling point. In standard conditions, ozone is a pale blue gas that condenses at cryogenic temperatures to a dark blue liquid and finally a violet-black solid. The molecule was later proven to have a bent structure and to be weakly diamagnetic. Ozone's O 3 structure was determined in 1865. Ozone's odor is reminiscent of chlorine, and detectable by many people at concentrations of as little as 0.1 ppm in air. It is present in very low concentrations throughout the latter, with its highest concentration high in the ozone layer of the stratosphere, which absorbs most of the Sun's ultraviolet (UV) radiation. Ozone is formed from dioxygen by the action of ultraviolet (UV) light and electrical discharges within the Earth's atmosphere. It is an allotrope of oxygen that is much less stable than the diatomic allotrope OĢ, breaking down in the lower atmosphere to OĢ ( dioxygen). It is a pale blue gas with a distinctively pungent smell. Ozone ( / ˈ oʊ z oʊ n/) (or trioxygen) is an inorganic molecule with the chemical formula Oģ. |
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