IN: The Clark Sisters are an American gospel vocal group consisting of five sisters: Jacky Clark Chisholm (b. 1948), Denise Clark Bradford (b. 1953), Elbernita "Twinkie" Clark-Terrell (b. 1954), Dorinda Clark-Cole (b. 1957), and Karen Clark Sheard (b. 1960). The Clark Sisters are the daughters of gospel musician and choral director Mattie Moss Clark. They are credited for helping to bring gospel music to the mainstream and are considered as pioneers of contemporary gospel.

After a four-year gap between releases, the sisters continued as a foursome, signing with Rejoice Records, a division of Word. This new deal yielded the Grammy-nominated Heart & Soul (1986) featuring the mainstream single "Time Out". This project made a top 5 debut on Billboard's Gospel Charts and garnered the group a coveted Dove Award. It featured the original versions of "Jesus Is A Love Song", "Balm in Gilead", and "Pray for the USA", which has been re-recorded several times. The music took on a more contemporary sound with programmed drums and synthesizers. Also included on this album were "Smile, God Loves You", "Time Out", "I Am Blessed", and the funky "He'll Turn Your Scars Into Stars." In 1988, The Clark Sisters released their Billboard chart-topping and critically acclaimed album Conqueror. It featured a bolder, more intense sound, with synthesizers, drum machines and more funk-oriented beats. Conqueror quickly became a fan favorite with hits like "The Darkest Hour Is Just Before The Day" and the original studio version of "Jesus Forevermore". In 1989, The Clark Sisters released their highly anticipated live album, Bringing it Back Home, recorded in their home town of Detroit. It was the last recording from The Clark Sisters on Word Records' Rejoice imprint and the last group album with Twinkie just before the launch of her solo career. The album included both previous hits and new material. It featured guest appearances from gospel icon Rance Allen and backing choir vocals from The Michigan State Choir directed by Dr. Mattie Moss Clark. In 1994, the Clark Sisters released their last studio album before breaking grounds into their successful solo careers. Their last studio album of the decade, Miracle, was the first album The Clark Sisters recorded without the songwriting and vocals of Twinkie Clark. Produced by BeBe Winans & Michael J. Powell, this disc features a very pop version of the Clark Sisters classic "Expect A Miracle" (now titled "Miracle") and a remake of the classic "Jesus Is The Best Thing". Dorinda made her songwriting debut on a Clark Sisters recording with "Work To Do". That album, although it fared well in sales, did not match the success of previous albums due to the Clark Sisters not being able to tour and promote the project, due to the illness of their mother, Dr. Mattie Moss Clark, who died in September 1994 from diabetes complications.

any other successes?

OUT: In 1989, The Clark Sisters released their highly anticipated live album, Bringing it Back

IN: Fazlur Rahman Khan (Bengali: phjlur rhmaan khaan, Fozlur Rohman Khan) (3 April 1929 - 27 March 1982) was a Bangladeshi-American structural engineer and architect, who initiated important structural systems for skyscrapers. Considered the "father of tubular designs" for high-rises, Khan was also a pioneer in computer-aided design (CAD). He was the designer of the Sears Tower, since renamed Willis Tower, the tallest building in the world from 1973 until 1998, and the 100-story John Hancock Center. Khan, more than any other individual, ushered in a renaissance in skyscraper construction during the second half of the 20th century.

Khan's central innovation in skyscraper design and construction was the idea of the "tube" structural system for tall buildings, including the framed tube, trussed tube, and bundled tube variants. His "tube concept", using all the exterior wall perimeter structure of a building to simulate a thin-walled tube, revolutionized tall building design. Most buildings over 40 stories constructed since the 1960s now use a tube design derived from Khan's structural engineering principles. Lateral loads (horizontal forces) such as wind forces, seismic forces, etc., begin to dominate the structural system and take on increasing importance in the overall building system as the building height increases. Wind forces become very substantial, and forces caused by earthquakes, etc. are important as well. The tubular designs resist such forces for tall buildings. Tube structures are stiff and have significant advantages over other framing systems. They not only make the buildings structurally stronger and more efficient, but also significantly reduce the structural material requirements. The reduction of material makes the buildings economically more efficient and reduces environmental impact. The tubular designs enable buildings to reach even greater heights. Tubular systems allow greater interior space and further enable buildings to take on various shapes, offering added freedom to architects. These new designs opened an economic door for contractors, engineers, architects, and investors, providing vast amounts of real estate space on minimal plots of land. Khan was among a group of engineers who encouraged a rebirth in skyscraper construction after a hiatus of over thirty years. The tubular systems have yet to reach their limit when it comes to height. Another important feature of the tubular systems is that buildings can be constructed using steel or reinforced concrete, or a composite of the two, to reach greater heights. Khan pioneered the use of lightweight concrete for high-rise buildings, at a time when reinforced concrete was used for mostly low-rise construction of only a few stories in height. Most of Khan's designs were conceived considering pre-fabrication and repetition of components so projects could be quickly built with minimal errors. The population explosion, starting with the baby boom of the 1950s, created widespread concern about the amount of available living space, which Khan solved by building upward. More than any other 20th-century engineer, Fazlur Rahman Khan made it possible for people to live and work in "cities in the sky." Mark Sarkisian (Director of Structural and Seismic Engineering at Skidmore, Owings & Merrill) said, "Khan was a visionary who transformed skyscrapers into sky cities while staying firmly grounded in the fundamentals of engineering."

Does this system help when the building collapse?

OUT:
Another important feature of the tubular systems is that buildings can be constructed using steel or reinforced concrete, or a composite of the two,