Silver Lake Reservoir
The Silver Lake Reservoirs comprise two concrete-lined basins, Ivanhoe Reservoir and Silver Lake, divided by a spillway, in the Silver Lake community of Los Angeles, California. The lower body of water was named in 1906 for Water Board Commissioner Herman Silver, in turn lends its name to the neighborhood; the upper body received its name after the 1819 Sir Walter Scott novel Ivanhoe. The reservoirs are owned and maintained by the Los Angeles Department of Water and Power, could provide water to 600,000 homes in downtown and South Los Angeles. Only the smaller of the two, remains online. At capacity, it holds 795 million US gallons of water; the Silver Lake Reservoir's water resources will be replaced by the Headworks Reservoir, an underground reservoir north of Griffith Park, slated for completion by December 2017. The reservoir is the focal point of the community and has evolved as a regional recreational resource, it is surrounded by several recreational areas, including a dog park on the south, a nursery school on the north, the Silver Lake Recreation Center, which includes a basketball court on the south side of the lake.
There is a walking and jogging path, which stretches 2.2 miles around the reservoir. In April 2011, the City of Los Angeles opened up for public use a three-acre passive park on the east side of the lake dubbed the "Silver Lake Meadow," modeled after the Sheep Meadow in New York's Central Park. In January 2014, some local residents proposed transforming the Ivanhoe part of the reservoir into a public, beach-like swimming venue titled "Silver Lake Plunge" but informally dubbed "Hipster Beach." In December 2007, the DWP announced that the Silver Lake and Ivanhoe reservoirs had both become contaminated with unusually high levels of the cancer-causing chemical bromate, were isolated. The reservoirs were both drained over several weeks in March 2008, refilled in May 2008. Two months 400,000 black hollow plastic shade balls were placed in Ivanhoe, which remains in use, to reduce the likelihood of the sunlight-fueled bromate. Silver Lake Reservoir was taken offline permanently; this incident pointed out the necessity of protecting the water supply by using underground tanks.
The black plastic balls were created in Pennsylvania by Orange Products Inc.. The balls are used at airports to prevent birds from landing in water runoff, thus preventing birds from being drawn into aircraft engines; the balls were certified by NSF International which certifies the safety of food and consumer goods. In February 2013 LADWP contracted with Glendora, California-based manufacturer XavierC LLC to supply an additional 6.4 million hollow plastic shade balls for reservoirs. List of dams and reservoirs in California List of lakes in California Mr. Sunset. "13 Facts About The Silver Lake Reservoir". Take Sunset. Retrieved 2009-09-05. 8. Http://info.nsf.org/Certified/PwsComponents/Listings.asp? Company=4G760&Standard=061 Los Angeles Department of Water and Power official website Historic image gallery at Silver Lake.org Silver Lake Reservoirs Conservancy Silver Lake Reservoir at Yelp
Dasani is a brand of bottled water from the Coca-Cola company, launched in 1999, after the success of Aquafina. It is one of many brands of Coca-Cola bottled water sold around the world; the product is tap water and bottled. Coca-Cola uses tap water from local municipal water supplies, filters it using the process of reverse osmosis, adds trace amounts of minerals, including magnesium sulfate, potassium chloride and table salt. Coca-Cola announced they would be distributing Dasani water in new packaging made of 30% plant-based materials. Unlike other plant-based packaging, the bottles are compatible with standard recycling plants and represent up to a 25% reduction in carbon emissions when compared to standard water bottles, though this still represents 2000 times the energy usage of tap water. Dasani was launched in all provinces of Canada except Quebec in 2000, a year after launching in the United States; the brand was made available in Quebec shortly afterwards, in April 2001. There are six common Dasani bottle sizes sold in Canada: 355 mL, 500mL, 591 mL, 710 mL, 1 L, 1.5 L. Bottles are sold individually and in packs of 6, 12, 24.
The first source of Dasani water in Canada was Alberta. A second bottling plant was opened in Brampton, Ontario; the Calgary and Brampton plants produce Coca-Cola's sugar-water products. The company's administrative and marketing activities continue to be based in Georgia. Dasani has <35 ppm of total dissolved mineral salts. In early 2005, two flavored versions of Dasani were introduced: Dasani With Lemon and Dasani With Raspberry. Dasani with Strawberry has since been introduced; the flavored beverages are sweetened with sucralose. Dasani was introduced to the Brazilian market in mid-2003, renamed as Aquarius, it was introduced to the Chilean market in 2005, including releases in regular and tangerine flavors. It was released in Colombia in late 2005 with their three regular flavors. In 2005, Dasani was introduced in the Argentinian market with the flavours peach, lemon and regular, it was released under the name Ciel Dasani in Mexico in four flavours: lemon-cucumber, papaya-carrot and mandarin-green tea, but it was discontinued in 2006.
It was released in Peru, Paraguay and Honduras. Dasani was launched in the UK on 10 February 2004; the product launch was labelled "a disaster", a "fiasco", a "PR catastrophe". Prior to the launch, an article in The Grocer trade magazine had mentioned that the source of the Dasani brand water was treated tap water from Sidcup, a suburban area on the outskirts of London. By early March 2004, the mainstream press had picked up the story and it became reported that Sidcup tap water, after being processed by reverse osmosis, had been remineralized and sold under the Dasani brand name in the UK. Although Coca-Cola never implied that the water was being sourced from a spring or other natural sources, they marketed it as being "pure"; this led the Food Standards Agency to request Hillingdon trading standards officers to launch an investigation into whether the claim was accurate. Richard May, Chief Publicity Officer of Dasani, was said to be disappointed that the water had not been more successful.
On 18 March 2004, UK authorities found a concentration of bromate, a suspected human carcinogen, in the product that could be considered harmful if consumed in large quantities. Coca-Cola recalled half a million bottles and withdrew the "Dasani" brand from the UK market. Shortly after, plans to introduce the brand to Continental Europe were announced to have been cancelled as well. Bromate was not present in the water before Coca-Cola's treatment process. During that process, the bromate was produced from the water’s bromide by exposure to ozone. Coca-Cola intended to launch Dasani in France and Germany, although this never went ahead after bad publicity in the United Kingdom. In line with the 2012 Summer Olympics and being the official drink sponsor, Coca-Cola decided not to reintroduce the Dasani brand to the UK market, purchased the Morpeth, Northumberland-based Abbey Well bottler in 2008, branded under the Schweppes brand name to provide a locally sourced water brand for the event. To meet Olympic branding regulations, Abbey Well water was labeled as "Still Water" for on-camera appearances during the Games.
In Ireland, it is marketed as Deep River Rock. Dasani website for U. S. residents "Coke Announces Dasani Water". Beverage Digest. February 1999
KNBC, channel 4, is an NBC owned-and-operated television station in Los Angeles, United States. The station is owned by the NBC Owned Television Stations subsidiary of the NBCUniversal division of Comcast, as part of a duopoly with Corona-licensed Telemundo owned-and-operated station KVEA; the two stations share offices on Lankershim Boulevard in northern Universal City. In the few areas of the western United States where an NBC station is not receivable over-the-air, KNBC is available on satellite television through DirecTV. Channel 4 first went on the air as KNBH on January 16, 1949, it was the penultimate VHF station in Los Angeles to debut, the last of NBC's five original owned-and-operated stations to sign on. Unlike the other four, KNBH was the only NBC-owned television station that did not benefit from having a sister radio station. Though the NBC Radio Network had long been affiliated with KFI in Los Angeles, that relationship did not extend into television when KFI-TV signed on in August 1948.
When KNBH signed on, it marked the debut of NBC programs on the West Coast. Channel 4 broadcast from the NBC Radio City Studios on Sunset Boulevard and Vine Street in Hollywood; the station changed its callsign to KRCA on October 18, 1954. The call letters were changed again on November 11, 1962, when NBC moved the KNBC identity from its San Francisco radio station and applied it to channel 4 in Los Angeles; that call letter change coincided with the station's physical relocation from NBC Radio City to the network's color broadcast studio facility in suburban Burbank. NBC Color City, as it was known, had been in operation since March 1955, was at least four to five times larger than Radio City, could accommodate KNBC's locally produced studio programming. NBC Radio's West Coast operations followed channel 4 to Burbank not too long after; the station modified its callsign to KNBC-TV in August 1986, shortly after NBC and RCA were purchased by General Electric. On October 11, 2007, NBCUniversal announced that it would put its Burbank studios up for sale and construct a new, all-digital facility near the Universal Studios Hollywood backlot in Universal City, in an effort to merge all of NBCUniversal's West Coast operations into one area.
As a result, KNBC, KVEA and NBC News' Los Angeles bureau moved to a new digital facility on the Universal lot occupied by Technicolor SA. The studio opened on February 1, 2014. Shortly thereafter, NBCUniversal named the new broadcast center in honor of former KNBC and NBC News anchor/reporter Tom Brokaw, christened the Brokaw News Center. In fall 2007 with digital broadcast roll out, the station began broadcasting a 24/7 newschannel News Raw on a subchannel. On January 16, 2009, KNBC celebrated its 60th anniversary with an hour-long tribute to the station, featuring past and present anchors, other popular on-air staff, major news stories. KNBC and its other NBC owned-and-operated stations introduced a new layout for their websites in July 2009; the station's digital channel is multiplexed: KNBC maintains a Mobile DTV feed of subchannel 4.1, labelled "KNBC-4.1", broadcasting at 1.83 Mbit/s. On January 1, 2014, Universal Sports transitioned into a cable- and satellite-exclusive service, causing its affiliates to replace the network and remove the channel from their digital signals with KNBC deleting digital subchannel 4.4 as result of the loss of Universal Sports.
KNBC operated NBC California Nonstop, a collaboration between KNBC and two other NBC-owned stations in California which launched on May 3, 2011 and replaced programming from NBC Plus on the second digital subchannels of all three stations. In the case of KNBC, it was the second news-oriented digital channel operated by the station, as digital channel 4.2 featured a rolling news format under the name NewsRaw, prior to the launch of California Nonstop. Each station produced a local newscast at 7 p.m., tailored to their respective market. For the Los Angeles feed of the channel, Colleen Williams anchored the hour-long Nonstop News LA. NBC California Nonstop ended on December 2012 when Cozi TV was launched. KNBC shut down its analog signal, over VHF channel 4, on June 12, 2009, as part of the federally mandated transition from analog to digital television; the station's digital signal remained on its pre-transition UHF channel 36, using PSIP to display KNBC's virtual channel as 4 on digital television receivers.
Since the station qualified for the nightlight clause in the DTV Delay Act, it was required to keep its analog signal on for two weeks from June 12 to 26, 2009 to inform viewers of the digital television transition, consisting of a loop of digital transition public service announcements, while the digital channel was used for normal programming. KNBC has a legacy of participating in the community; the station supports many social causes including health and wellness, the environment and supports under-served populations like the homeless, veterans, at-risk youth and women's issues. KNBC has been recognized by many nonprofit organizations for its community work, has partnerships with several prominent organizations including the L. A. Alliance of Boys & Girls Clubs, Court Appointed Special Advocates Los Angeles, California Community Foundation, American Red Cross Los Angeles, Mar
A conjugate acid, within the Brønsted–Lowry acid–base theory, is a chemical compound formed by the reception of a proton by a base—in other words, it is a base with a hydrogen ion added to it. On the other hand, a conjugate base is what is left over after an acid has donated a proton during a chemical reaction. Hence, a conjugate base is a species formed by the removal of a proton from an acid; because some acids are capable of releasing multiple protons, the conjugate base of an acid may itself be acidic. In summary, this can be represented as the following chemical reaction: Acid + Base ⇌ Conjugate Base + Conjugate Acid Johannes Nicolaus Brønsted and Martin Lowry introduced the Brønsted–Lowry theory, which proposed that any compound that can transfer a proton to any other compound is an acid, the compound that accepts the proton is a base. A proton is a nuclear particle with a unit positive electrical charge. A cation can be a conjugate acid, an anion can be a conjugate base, depending on which substance is involved and which acid–base theory is the viewpoint.
The simplest anion which can be a conjugate base is the solvated electron whose conjugate acid is the atomic hydrogen. In an acid-base reaction, an acid plus a base reacts to form a conjugate base plus a conjugate acid: Conjugates are formed when an acid loses a hydrogen proton or a base gains a hydrogen proton. Refer to the following figure: We say that the water molecule is the conjugate acid of the hydroxide ion after the latter received the hydrogen proton donated by ammonium. On the other hand, ammonia is the conjugate base for the acid ammonium after ammonium has donated a hydrogen ion towards the production of the water molecule. We can refer to OH- as a conjugate base of H2O, since the water molecule donates a proton towards the production of NH+4 in the reverse reaction, the predominating process in nature due to the strength of the base NH3 over the hydroxide ion. Based on this information, it is clear that the terms "Acid", "Base", "conjugate acid", "conjugate base" are not fixed for a certain chemical species.
The strength of a conjugate acid is directly proportional to its dissociation constant. If a conjugate acid is strong, its dissociation will have a higher equilibrium constant and the products of the reaction will be favored; the strength of a conjugate base can be seen as the tendency of the species to "pull" hydrogen protons towards itself. If a conjugate base is classified as strong, it will "hold on" to the hydrogen proton when in solution and its acid will not dissociate. On the other hand, if a species is classified as a strong acid, its conjugate base will be weak in nature. An example of this case would be the dissociation of Hydrochloric acid HCl in water. Since HCl is a strong acid, its conjugate base will be a weak conjugate base. Therefore, in this system, most H+ will be in the form of a Hydronium ion H3O+ instead of attached to a Cl anion and the conjugate base will be weaker than a water molecule. If an acid is weak, its conjugate base will be strong; when considering the fact that the Kw is equal to the product of the concentrations of H+ and OH.
A weak acid will have a low concentration of H+. The Kw divided by a low H+ concentration will result in a low OH- concentration as well. Therefore, weak acids will have weak conjugate bases, unlike the misconception that they have strong conjugate bases; the acid and conjugate base as well as the base and conjugate acid are known as conjugate pairs. When finding a conjugate acid or base, it is important to look at the reactants of the chemical equation. In this case, the reactants are the acids and bases, the acid corresponds to the conjugate base on the product side of the chemical equation. To identify the conjugate acid, look for the pair of compounds that are related; the acid–base reaction can be viewed in a before and after sense. The before is the reactant side of the after is the product side of the equation; the conjugate acid in the after side of an equation gains a hydrogen ion, so in the before side of the equation the compound that has one less hydrogen ion of the conjugate acid is the base.
The conjugate base in the after side of the equation lost a hydrogen ion, so in the before side of the equation, the compound that has one more hydrogen ion of the conjugate base is the acid. Consider the following acid–base reaction: HNO3 + H2O → H3O+ + NO−3Nitric acid is an acid because it donates a proton to the water molecule and its conjugate base is nitrate; the water molecule acts as a base because it receives the Hydrogen Proton and its conjugate acid is the hydronium ion. One use of conjugate acids and bases lies in buffering systems. In a buffer, a weak acid and its conjugate base, or a weak base and its conjugate acid, are used in order to limit the pH change during a titration process. Buffers have both non-organic chemical applications. For example, besides buffers being used in lab processes, our blood acts as a buffer to maintain pH; the most important buffer in our bloodstream is the carbonic acid-bicarbonate buffer, which prevents drastic pH changes when CO2 is introduced. This functions as such: CO 2 + H 2 O ↽ − − ⇀ H 2 CO 3 ↽
A chemical compound is a chemical substance composed of many identical molecules composed of atoms from more than one element held together by chemical bonds. A chemical element bonded to an identical chemical element is not a chemical compound since only one element, not two different elements, is involved. There are four types of compounds, depending on how the constituent atoms are held together: molecules held together by covalent bonds ionic compounds held together by ionic bonds intermetallic compounds held together by metallic bonds certain complexes held together by coordinate covalent bonds. A chemical formula is a way of expressing information about the proportions of atoms that constitute a particular chemical compound, using the standard abbreviations for the chemical elements, subscripts to indicate the number of atoms involved. For example, water is composed of two hydrogen atoms bonded to one oxygen atom: the chemical formula is H2O. Many chemical compounds have a unique numerical identifier assigned by the Chemical Abstracts Service: its CAS number.
A compound can be converted to a different chemical composition by interaction with a second chemical compound via a chemical reaction. In this process, bonds between atoms are broken in both of the interacting compounds, bonds are reformed so that new associations are made between atoms. Any substance consisting of two or more different types of atoms in a fixed stoichiometric proportion can be termed a chemical compound, it follows from their being composed of fixed proportions of two or more types of atoms that chemical compounds can be converted, via chemical reaction, into compounds or substances each having fewer atoms. The ratio of each element in the compound is expressed in a ratio in its chemical formula. A chemical formula is a way of expressing information about the proportions of atoms that constitute a particular chemical compound, using the standard abbreviations for the chemical elements, subscripts to indicate the number of atoms involved. For example, water is composed of two hydrogen atoms bonded to one oxygen atom: the chemical formula is H2O.
In the case of non-stoichiometric compounds, the proportions may be reproducible with regard to their preparation, give fixed proportions of their component elements, but proportions that are not integral. Chemical compounds have a unique and defined chemical structure held together in a defined spatial arrangement by chemical bonds. Chemical compounds can be molecular compounds held together by covalent bonds, salts held together by ionic bonds, intermetallic compounds held together by metallic bonds, or the subset of chemical complexes that are held together by coordinate covalent bonds. Pure chemical elements are not considered chemical compounds, failing the two or more atom requirement, though they consist of molecules composed of multiple atoms. Many chemical compounds have a unique numerical identifier assigned by the Chemical Abstracts Service: its CAS number. There is varying and sometimes inconsistent nomenclature differentiating substances, which include non-stoichiometric examples, from chemical compounds, which require the fixed ratios.
Many solid chemical substances—for example many silicate minerals—are chemical substances, but do not have simple formulae reflecting chemically bonding of elements to one another in fixed ratios. It may be argued that they are related to, rather than being chemical compounds, insofar as the variability in their compositions is due to either the presence of foreign elements trapped within the crystal structure of an otherwise known true chemical compound, or due to perturbations in structure relative to the known compound that arise because of an excess of deficit of the constituent elements at places in its structure. Other compounds regarded as chemically identical may have varying amounts of heavy or light isotopes of the constituent elements, which changes the ratio of elements by mass slightly. Compounds are held together through a variety of different types of bonding and forces; the differences in the types of bonds in compounds differ based on the types of elements present in the compound.
London dispersion forces are the weakest force of all intermolecular forces. They are temporary attractive forces that form when the electrons in two adjacent atoms are positioned so that they create a temporary dipole. Additionally, London dispersion forces are responsible for condensing non polar substances to liquids, to further freeze to a solid state dependent on how low the temperature of the environment is. A covalent bond known as a molecular bond, involves the sharing of electrons between two atoms; this type of bond occurs between elements that fall close to each other on the periodic table of elements, yet it is observed between some metals and nonmetals. This is due to the mechanism of this type of bond. Elements that fall close to each other on the periodic table tend to have similar electronegativities, which means they have a similar affinity for electrons. Since neither element has a stronger affinity to donate or gain electrons, it causes the elements to share electrons so both elements have a more stable octet.
Ionic bonding occurs when valence electrons are transferred between elements. Opposite to covalent bonding, this chemical bond creates two oppositely charged ions; the metals in ionic bonding
The Jmol applet, among other abilities, offers an alternative to the Chime plug-in, no longer under active development. While Jmol has many features that Chime lacks, it does not claim to reproduce all Chime functions, most notably, the Sculpt mode. Chime requires plug-in installation and Internet Explorer 6.0 or Firefox 2.0 on Microsoft Windows, or Netscape Communicator 4.8 on Mac OS 9. Jmol operates on a wide variety of platforms. For example, Jmol is functional in Mozilla Firefox, Internet Explorer, Google Chrome, Safari. Chemistry Development Kit Comparison of software for molecular mechanics modeling Jmol extension for MediaWiki List of molecular graphics systems Molecular graphics Molecule editor Proteopedia PyMOL SAMSON Official website Wiki with listings of websites and moodles Willighagen, Egon. "Fast and Scriptable Molecular Graphics in Web Browsers without Java3D". Doi:10.1038/npre.2007.50.1
Shade balls are small plastic spheres floated on top of a reservoir for environmental protection and to slow evaporation. Known as bird balls, they were developed to prevent birds from landing on toxic tailing ponds produced by mining operations, they have been used by airports to prevent birds from being attracted to drainage ponds and thus risking collisions with planes. Shade balls were known as bird balls, as they were developed to prevent birds from landing on toxic tailing ponds produced by mining operations, they have been used by airports to prevent birds from being attracted to drainage ponds and thus risking collisions with planes. Starting in mid-2008, the Los Angeles Department of Water and Power deployed about 400,000 of these devices in the Ivanhoe reservoir with the main objective of preventing the formation of a carcinogenic chemical, which forms when occurring bromine reacts with chlorine in the presence of sunlight. In the original release by the LADWP, there is no mention of water conservation as an objective, the project was planned for a five year life span, until a Griffith Park project was completed.
However, the reduction in evaporation led to an estimated savings of about 1.1 billion liters of water in one year. In 2014 and 2015, the LADWP deployed 96 million shade balls on its largest reservoir in response to the United States Environmental Protection Agency's surface water treatment rule, which requires large reservoirs of treated water to be covered; the LADWP claims that in addition to reducing evaporation, they will reduce UV radiation by-products and algae growth. The balls saved 1.7 million cubic metres of water from evaporating during their deployment from August 2015 to March 2017. However they required 2.9 million cubic metres of water in their manufacture. The balls have a lifespan of ten years, the plastic may be reused after that; the shade balls used in the Los Angeles project are made of high-density polyethylene with carbon black additive to protect the plastic from ultraviolet radiation. Adding carbon black prevents the formation of bromate, a suspected human carcinogen.
They are about 4 inches in diameter, are filled with water to avoid being blown by wind. HDPE plastic is used for food and beverage containers as well as water distribution pipes; the black coating on the balls, called carbon black, is a petroleum derivative, classified as a carcinogen if inhaled as dust. The black color balls have been claimed to prevent UV light from reaching the water more than lighter color balls. Video of 2014 Shade Ball Deployment on YouTube