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Racemic mixture

In chemistry, a racemic mixture, or racemate, is one that has equal amounts of left- and right-handed enantiomers of a chiral molecule. The first known racemic mixture was racemic acid, which Louis Pasteur found to be a mixture of the two enantiomeric isomers of tartaric acid. A sample with only a single enantiomer is an enantiomerically enantiopure compound. From racemic acid found in grapes; this acid, when produced in grapes, is only the right-handed version of the molecule, better known as tartaric acid. A racemic mixture is denoted by the prefix - or dl-, indicating an equal mixture of dextro and levo isomers; the prefix rac- or the symbols RS and SR are used. If the ratio is not 1:1, the prefix /, d/l- or d/l- is used instead; the usage of d and l is discouraged by IUPAC. A racemate is optically inactive, meaning. Although the two enantiomers rotate plane-polarized light in opposite directions, the rotations cancel because they are present in equal amounts. In contrast to the two pure enantiomers, which have identical physical properties except for the direction of rotation of plane-polarized light, a racemate sometimes has different properties from either of the pure enantiomers.

Different melting points are most common, but different solubilities and boiling points are possible. Pharmaceuticals may be available as a racemate or as the pure enantiomer, which might have different potencies; because biological systems have many chiral asymmetries, pure enantiomers have different biological effects. There are four ways. Roozeboom had distinguished by 1899: Conglomerate If the molecules of the substance have a much greater affinity for the same enantiomer than for the opposite one, a mechanical mixture of enantiomerically pure crystals will result; the melting point of the racemic conglomerate is always lower than that of the pure enantiomer. Addition of a small amount of one enantiomer to the conglomerate increases the melting point. 10% of racemic chiral compounds crystallize as conglomerates. Racemic compound If molecules have a greater affinity for the opposite enantiomer than for the same enantiomer, the substance forms a single crystalline phase in which the two enantiomers are present in an ordered 1:1 ratio in the elementary cell.

Adding a small amount of one enantiomer to the racemic compound decreases the melting point. But the pure enantiomer can have a lower melting point than the compound. A special case of racemic compounds are kryptoracemates, in which the crystal itself has handedness, despite containing both enantiomorphs in a 1:1 ratio. Pseudoracemate When there is no big difference in affinity between the same and opposite enantiomers in contrast to the racemic compound and the conglomerate, the two enantiomers will coexist in an unordered manner in the crystal lattice. Addition of a small amount of one enantiomer changes the melting point or not at all. Quasiracemate A quasiracemate is a co-crystal of two similar but distinct compounds, one of, left-handed and the other right-handed. Although chemically different, they are sterically similar and are still able to form a racemic crystalline phase. One of the first such racemates studied, by Pasteur in 1853, forms from a 1:2 mixture of the bis ammonium salt of -tartaric acid and the bis ammonium salt of -malic acid in water.

Re-investigated in 2008, the crystals formed are dumbbell-shape with the central part consisting of ammonium -bitartrate, whereas the outer parts are a quasiracemic mixture of ammonium -bitartrate and ammonium -bimalate. The separation of a racemate into its components, the pure enantiomers, is called a chiral resolution. There are various methods, including crystallization and the use of enzymes; the first successful resolution of a racemate was performed by Louis Pasteur, who manually separated the crystals of a conglomerate. Without a chiral influence, a chemical reaction that makes a chiral product will always yield a racemate; that can make the synthesis of a racemate cheaper and easier than making the pure enantiomer, because it does not require special conditions. This fact leads to the question of how biological homochirality evolved on what is presumed to be a racemic primordial earth; the reagents of, the reactions that produce, racemic mixtures are said to be "not stereospecific" or "not stereoselective", for their indecision in a particular stereoisomerism.

A frequent scenario is that of a planar species acting as an electrophile. The nucleophile will have a 50% probability of'hitting' either of the two sides of the planar grouping, thus producing a racemic mixture: Some drug molecules are chiral, the enantiomers have different effects on biological entities, they can be sold as a racemic mixture. Examples include thalidomide and salbutamol. Adderall is an unequal mixture of both amphetamine enantiomers. A single amphetamine dose combines the neutral sulfate salts of dextroamphetamine and amphetamine, with the dextro isomer of amphetamine saccharate and D/L-amphetamine aspartate monohydrate; the prescription analgesic tramadol is a racemate. In some cases, the enantiomers in

AAC Angel

The Angel Aircraft Corporation Model 44 Angel is a twin-engine STOL utility aircraft produced in the United States since the mid-1990s. Designed by Carl Mortenson and The King's Engineering Fellowship to be well-suited for missionary work from remote locations around the world, it is a low-wing cantilever monoplane with a retractable tricycle undercarriage and eight seats; the design is conventional, with the exception that the engine nacelles are mounted on top of the wings in a pusher configuration. Construction is aluminum throughout the airframe. Design work began at the home of designer Carl Mortenson in 1972, with work on the prototype beginning in 1977 from the designer's home. In 1980 the project was moved to the municipal airport in Iowa; the first flight took place on 13 January 1984, FAA type certification was achieved on 20 October 1992. Angel Aircraft Corporation manufactures the aircraft under a license agreement with The King's Engineering Fellowship. Four aircraft were placed between 1984 and 2008 but Hubei Taihang Xinghe Aircraft Manufacturing of China acquired a production license in 2013.

The first Chinese example was completed in May 2016 before the Hubei local government financed a manufacturing plant. The Model 44 was approved on July 2015, by the Chinese National Civil Aviation Administration. On 14 December 2019, an Angel 44 crashed into a field of corn near the airport at Mareeba, Australia at 11.15am during what is believed to be a training flight. The aircraft has been said to be the only example of the type in Australia; the pilot, William Scott-Bloxam and male passenger died at the scene of the incident. Data from Jane's All The World's Aircraft 1993–94General characteristics Crew: one Capacity: seven Length: 33 ft 6 in Wingspan: 39 ft 11.5 in Height: 11 ft 6 in Wing area: 225.4 sq ft Empty weight: 3,880 lb Gross weight: 5,800 lb Powerplant: 2 × Lycoming IO-540-M1C5 air-cooled flat-six, 300 hp eachPerformance Maximum speed: 180 kn Cruise speed: 169 kn 65% power Stall speed: 57 kn Range: 1,720 nmi max, 1,248 nmi at 65% Endurance: 13 h 6 min Service ceiling: 19,015 ft Rate of climb: 1,345 ft/min Evangel 4500 – another Mortenson twin-engine STOL design Softex-Aero V-24 Dekkers, Hans.

"Flying the Angel 44". Flight International. Pp. 25–26. Retrieved 15 September 2008. Lambert, Mark. Jane's All The World's Aircraft 1993–94. Coulsdon, UK: Jane's Data Division. ISBN 0-7106-1066-1. CS1 maint: extra text: authors list Simpson, R. W.. Airlife's General Aviation. Shrewsbury: Airlife Publishing. P. 416. Taylor, Michael J. H.. Jane's Encyclopedia of Aviation. London: Studio Editions. P. 932. Taylor, John W R. Jane's All the World's Aircraft 1987–88. London: Jane's Publishing. Pp. 439–440. Walters, Brian M.. "Wings of an Angel". Air International. Vol. 45 no. 4. Stamford, UK. pp. 213–214. ISSN 0306-5634. Official Website Angel brochure on manufacturer's website Type Certificate Data Sheet A2WI

Achkhoy-Martan

Achkhoy-Martan is a rural locality in, the administrative center of Achkhoy-Martanovsky District, Chechnya. Municipally, Achkhoy-Martan is incorporated as Achkhoy-Martanovskoye rural settlement, it is the only settlement included in it. Achkhoy-Martan, the largest rural settlement in Chechnya, is the administrative center of Achkhoy-Martanovsky District; the Fortanga River flows through the center of the village. To the east of the village is the Achkhu River; the name of the village comes from these two rivers. Achkhoy-Martan is located 40 kilometres south-west of the city of Grozny; the nearest settlements to Achkhoy-Martan are Novy Sharoy in the north, Shaami-Yurt in the north-east, Katyr-Yurt in the east, Stary Achkhoy and Yandi in the south-east, Bamut in the south-west, Assinovskaya in the north-west. In 1944, after the genocide and deportation of the Chechen and Ingush people and the Chechen-Ingush ASSR was abolished, the village of Achkhoy-Martan was renamed to Novoselskoye, settled by people from other ethnic groups.

From 1944 to 1957, it was the administrative center of the Novoselsky District of Grozny Oblast. In 1957, when the Vaynakh people returned and the Chechen-Ingush ASSR was restored, the village regained its old name, Achkhoy-Martan. 1959 Census: 8,389 1970 Census: 12,250 1979 Census: 12,276 1989 Census: 14,680 1990 Census: 15,101 2002 Census: 16,742 2010 Census: 20,172 2019 estimate: 24,212According to the results of the 2010 Census, the majority of residents of Achkhoy-Martan were ethnic Chechens, with 59 people coming from other ethnic backgrounds. The district library in Achkhoy-Martan has around 70,000 books; the village hosts nine secondary schools, an eight-year school, three kindergartens, a youth center. Prior to the outbreak of hostilities, a boarding school was present in Achkhoy-Martan; the village hosts a mosque. The Achkhoy-Martan state farm exists in the village, engages in cereal crops, cattle breeding and gardening; the village hosts the largest seed processing plant in Chechnya, as well as a plastic factory, one of the largest bases of building materials in the republic.

The village has its own football club "Marta", volleyball team "Achkhoy", a sports club, hosts competitions in judo, karate and boxing. Tamerlan Bashaev, a judo champion.

Monah Li

Monah Li is a Viennese-born, Los Angeles-based fashion designer, best known for her feminine, deconstructed clothes. She is credited by numerous fashion writers with popularizing the post-modern Bohemian chic look and with starting the trend of up-cycling and re-purposing vintage dresses and slips, her dresses, cashmere sweaters and skirts have been featured in People Magazine, The Los Angeles Times, Los Angeles Magazine, "worn by celebrities such Christina Ricci, Salma Hayek, Nicole Kidman and Ione Skye." Other stars who have worn her clothes include Courtney Love, Cameron Diaz, Stevie Nicks, Salma Hayek, Barbra Streisand, Gina Gershon, Liv Tyler, Goldie Hawn, Jada Pinkett Smith and Madonna. She designed Alyssa Milano's wedding dress. Monah Li's clothes appeared on Friends and the original Beverly Hills, 90210 where they were referred to by the designer's name, she has designed for bebe stores as both as the head designer in the Los Angeles office, as a freelance designer. Her own labels include Monah Li Couture and Monahmour.

Monah Li opened her own eponymous boutique in Elysian Park, an area of Los Angeles between Hollywood and Downtown undergoing gentrification, a follow-up of the successful boutique she opened in the buddingly hip Los Feliz area in 1998. Monah Li's romantic, eclectic silhouettes are designed to be worn by women of all sizes, she favors "normal" and larger-sized models, as well as real women, over traditionally thin, professional fashion models in her shows. Her use of over-dyed silk and satin with lace insets, called the "rich Bohemian look" have made her one of the most knocked-off designers in her genre. In December 1999 she received a settlement from Italian designer Patty Shelabarger, who had offered to represent Li's line in Europe,"removed the labels from Li's clothing and sewed in her own."In addition to designing clothes, Monah Li is a published author and has written a screenplay, in pre-production. Her essay, "The Making of a Designer" appeared in the LA Weekly on April 10, 2003, she is a frequent contributor to The Huffington Post, writing about fashion, more her recovery from nineteen years of bulimia.

She contributed a story to Love Addict: Sex and Other Dangerous Drugs. Monah Li began her career as a teenager making her own clothes in Vienna, her dresses attracted attention and were bought by boutiques in her hometown and in Düsseldorf, Germany. One of the only female students to have attended the prestigious Higher Teaching Institute Industries in Austria, she graduated from textile engineering school with honors at age nineteen. Though accepted into Karl Lagerfeld's class at the Academy for Applied Art in Vienna, Li chose to pursue her career after her hand painted silk garments received a write up in German Vogue, before moving to Los Angeles where her psychiatrist mother was living to attend the Fashion Institute of Design & Merchandising. After a brief stint in Los Angeles where her growing drug use distracted her from school, Monah Li returned to Vienna, where she was hospitalized for addiction; as part of her rehab program, she went to work in a garment shop owned by the rehab's head of psychiatry, learning "couture' from the seamstresses who worked there.

After leaving the rehab program, she opened her own boutique in Vienna, winning the Best Designer of 1988 Award from the Austrian Wool Secretary. Monah Li returned to Los Angeles, after her first successful dress design was knocked off, founded her own company and began to create unique, one of-a-kind hand sewn garments, up-cycling vintage slips and sweaters with lace insets, lingerie fastening and straps, which she over-dyed. Finding success through sales to trend-setting retailers like Fred Segal, she opened a boutique on Vermont Avenues, which stocked her signature X-dress and other styles; the shop was described as one of "the best new stores in the city," and was credited with turning Vermont Avenue, the main street in the Los Feliz district of Los Angeles, into a hip shopping destination. She rallied a group of other local designers and founded the Coalition of Los Angeles Designers in 1998. In 1998 Monah Li was nominated as California Mart Rising Star. In 2000, Monah Li added perfume she designed and created to her boutique, branched out into large scale manufacturing of her designs for department stores.

A production contractor "did such shoddy work that stores nationwide returned the merchandise," costing her business $800,000 in two months. Despite the setback, she put together a fashion show for New York in Spring 2000, where reps from Bebe saw her designs and hired her as head designer for their newly created Los Angeles office. Bebe CEO and founder Manny Mashouf told the Los Angeles Times, "Her dresses are designed in terms of seams and details. They're sexy and feminine and have a fluid motion." Fashion writer Lauri Pike said. I think of those clothes as being a slutty, but if Monah Li designs for them, I'm going to watch it. If they want to pull ahead of their competition or appeal to older women, Monah Li could be helpful."Monah Li left bebe to restart her own label. She showed at Los Angeles Fashion Week in 2003, returned in 2004 with a "dramatically reinvented look" featuring richly colored solids and fur stoles, called "one of the most visually stimulating a

Vikram Singh Chauhan

Vikram Singh Chauhan is an Indian actor and model known for playing Atharva Ghosh in Jaana Na Dil Se Door and Aman Junaid Khan in Yehh Jadu Hai Jinn Ka!. Chauhan made his debut in 2013 with Qubool Hai as Imran Qureshi. Next, he appeared in Ek Hasina Thi. From 2016 to 2017, he played Atharv Sujata in Star Plus's Jaana Na Dil Se Door opposite Shivani Surve. From 2017 to 2018, he portrayed Vyom Bedi/Akash Khurana in Sony TV's Ek Deewaana Tha opposite Donal Bisht. Since October 2019, Chauhan had been playing Aman Junaid Khan in Star Plus's Yehh Jadu Hai Jinn Ka! Opposite Aditi Sharma. 2015: The Perfect Girl as Kartik 2019: Mardaani 2 as Anup List of Indian television actors List of Bollywood actors List of Indian Actors List of actors

Rancho Tehama Reserve shootings

On November 13/14, 2017, a series of shootings occurred in Rancho Tehama Reserve, an unincorporated community in Tehama County, California, U. S; the gunman, 44-year-old Kevin Janson Neal, died by suicide after a Corning police officer rammed and stopped his stolen vehicle. During the shooting spree, five people were killed and 18 others were injured at eight separate crime scenes, including an elementary school. Ten people suffered eight were cut by flying glass caused by the gunfire; the injured victims were transported to several area hospitals. At the time of the spree, Neal had been freed on bail pending trial for two alleged felonies, five alleged misdemeanors. Nine months before the shooting rampage, a judge had issued Neal a restraining order at a neighbor's request and ordered him to surrender his guns; the restraining order was renewed before the shootings. He possessed the handguns in violation of that restraining order. At least one unregistered semi-automatic ghost rifle and two borrowed semi-automatic pistols were used.

The shootings led to domestic and international debate over the control of ghost guns and gun-licensing law in the United States. The killings started on November 13 at Neal's home in Rancho Tehama Reserve, 6970 Bobcat Lane at Fawn Lane, when Neal shot his wife, Barbara Glisan and hid her body under some floorboards; the next day Neal went on a shooting rampage, first killing a man and a woman, both neighbors with whom he had an ongoing feud over their suspected methamphetamine dealing. After killing his neighbors, Neal stole a pickup truck, he began firing at random vehicles and pedestrians. At an intersection, he bumped the truck into a vehicle carrying her three sons, he drove up to the driver's side, fired into it, injuring all of them with gunshots or flying glass. The woman was shot four near her heart, she was carrying a gun and had a license to carry, but she was unable to shoot at Neal because he drove away quickly. She stopped four motorists to help her get to the hospital, she received aid from an assistant deputy sheriff who called for an ambulance.

At the Rancho Tehama Elementary School, Sarah Lobdell, the school's secretary, heard the gunfire near the school and ordered the school to go on lockdown. A school custodian and the teachers put it into action. Neal crashed the pickup truck through the front gates of the school, he exited the vehicle with a self-assembled AR-15-type semi-automatic rifle, ran into the center of the school's quadrangle, fired at windows and walls. One of Neal's neighbors claimed that Neal was targeting the seven-year-old son of the neighbor he killed earlier. One student hiding under a classroom desk was injured by a bullet that penetrated a wall. A six-year-old student was injured by a gunshot to the chest. A woman was shot when she attempted to distract Neal from the school. Nearly 100 rounds of ammunition were fired into the school. Recorded video shows Neal going into a field behind the school and firing into the air in frustration at being locked out of the classrooms. Afterwards, Neal discarded the rifle outside the school.

After fleeing the school, Neal crashed the pickup truck into another vehicle and fired at the two occupants as they tried to flee. The man survived after pleading with Neal for his life. A passerby, unaware of the shootings, asked Neal if he was okay; as Neal was chasing an innocent victim and shooting at them from his car, he was being pursued by law enforcement. The stolen truck was rammed by two law enforcement officers, one from the Corning Police Department, who responded from the city of Corning to assist the sheriff's office, a Tehama County Sheriff's deputy; as the truck came to a stop Neal attempted to ambush and kill the officers who exchanged heavy gunfire with him. Neal killed himself with a shot above his left eye; the 25-minute attack took place at eight crime scenes using one semi-automatic ghost rifle and two semi-automatic pistols. His motive is unclear. Two handguns and another AR-15-type rifle were recovered near his body; the handguns were not registered to him. The first shooting report to 9-1-1 was placed at 7:54 a.m. and Neal died at 8:19 a.m.—a duration of 25 minutes.

Five people were killed on the day of the shooting spree, including the perpetrator, who died by suicide after a confrontation with a police officer and a deputy sheriff. A sixth body, that of the shooter's wife 38-year-old Barbara Glisan, was discovered under the floorboards of their home, his neighbors, 38-year-old Danny Elliott and 68-year-old Diana Steele with whom he had had previous conflicts, were his first two killings on November 14. The other victims were 55-year-old Michelle McFadyen. Eleven other people—six adults and five children—were shot, but survived, they were taken to Enloe Medical Center in Chico, Saint Elizabeth Community Hospital in Red Bluff, Mercy Medical Center in Redding, or UC Davis Medical Center in Davis for treatment. The victims included two students at Rancho Tehama Elementary School and Michelle McFadyen's husband. One of the injured students, six-year-old Alejandro Hernandez, was the youngest victim. In addition, seven children suffered injuries from shattered glass