Structural engineering

Structural engineering is a sub-discipline of civil engineering in which structural engineers are trained to design the'bones and muscles' that create the form and shape of man made structures. Structural engineers need to understand and calculate the stability and rigidity of built structures for buildings and nonbuilding structures; the structural designs are integrated with those of other designers such as architects and building services engineer and supervise the construction of projects by contractors on site. They can be involved in the design of machinery, medical equipment, vehicles where structural integrity affects functioning and safety. See glossary of structural engineering. Structural engineering theory is based upon applied physical laws and empirical knowledge of the structural performance of different materials and geometries. Structural engineering design uses a number of simple structural engineers to build complex structural systems. Structural engineers are responsible for making creative and efficient use of funds, structural elements and materials to achieve these goals.

Structural engineering dates back to 2700 B. C. E; when the step pyramid for Pharaoh Djoser was built by Imhotep, the first engineer in history known by name. Pyramids were the most common major structures built by ancient civilizations because the structural form of a pyramid is inherently stable and can be infinitely scaled; the structural stability of the pyramid, whilst gained from its shape, relies on the strength of the stone from which it is constructed, its ability to support the weight of the stone above it. The limestone blocks were taken from a quarry near the build site and have a compressive strength from 30 to 250 MPa. Therefore, the structural strength of the pyramid stems from the material properties of the stones from which it was built rather than the pyramid's geometry. Throughout ancient and medieval history most architectural design and construction was carried out by artisans, such as stonemasons and carpenters, rising to the role of master builder. No theory of structures existed, understanding of how structures stood up was limited, based entirely on empirical evidence of'what had worked before'.

Knowledge was retained by guilds and supplanted by advances. Structures were repetitive, increases in scale were incremental. No record exists of the first calculations of the strength of structural members or the behavior of structural material, but the profession of structural engineer only took shape with the Industrial Revolution and the re-invention of concrete (see History of Concrete; the physical sciences underlying structural engineering began to be understood in the Renaissance and have since developed into computer-based applications pioneered in the 1970s. 1452–1519 Leonardo da Vinci made many contributions 1638: Galileo Galilei published the book Two New Sciences in which he examined the failure of simple 1660: Hooke's law by Robert Hooke 1687: Isaac Newton published Philosophiæ Naturalis Principia Mathematica which contains the Newton's laws of motion 1750: Euler–Bernoulli beam equation 1700–1782: Daniel Bernoulli introduced the principle of virtual work 1707–1783: Leonhard Euler developed the theory of buckling of columns 1826: Claude-Louis Navier published a treatise on the elastic behaviors of structures 1873: Carlo Alberto Castigliano presented his dissertation "Intorno ai sistemi elastici", which contains his theorem for computing displacement as partial derivative of the strain energy.

This theorem includes the method of "least work" as a special case 1874: Otto Mohr formalized the idea of a statically indeterminate structure. 1922: Timoshenko corrects the Euler-Bernoulli beam equation 1936: Hardy Cross' publication of the moment distribution method, an important innovation in the design of continuous frames. 1941: Alexander Hrennikoff solved the discretization of plane elasticity problems using a lattice framework 1942: R. Courant divided a domain into finite subregions 1956: J. Turner, R. W. Clough, H. C. Martin, L. J. Topp's paper on the "Stiffness and Deflection of Complex Structures" introduces the name "finite-element method" and is recognized as the first comprehensive treatment of the method as it is known today The history of structural engineering contains many collapses and failures. Sometimes this is due to obvious negligence, as in the case of the Pétion-Ville school collapse, in which Rev. Fortin Augustin "constructed the building all by himself, saying he didn't need an engineer as he had good knowledge of construction" following a partial collapse of the three-story schoolhouse that sent neighbors fleeing.

The final collapse killed 94 people children. In other cases structural failures require careful study, the results of these inquiries have resulted in improved practices and greater understanding of the science of structural engineering; some such studies are the result of forensic engineering investigations where the original engineer seems to have done everything in accordance with the state of the profession and acceptable practice yet a failure still eventuated. A famous case of structural knowledge and practice being advanced in this manner can be found in a series of failures involving box girders which collapsed in Australia during the 1970s. Structural engineering depends upon a detailed knowledge of applied mechanics, materials science and applied mathematics to understand and predict how structures support and resist self-weight and imposed loads. To apply the knowledge a structural engineer requires detailed knowledge of relevant empirical

One More Step

One More Step is the second studio album by American contemporary Christian music recording artist Lindsay McCaul. The album was released via Centricity Music on August 19, 2014. Production was helmed by Jeff Pardo. On behalf of Jesus Freak Hideout, Jen Rose Yokel depicts that "It doesn't beg to stand out, become a hit record, or try to reinvent her art, but it does mark a progression in the right direction and offers an encouraging collection of honest songs for those willing to spend time listening." Writing for Cross Rhythms, A T Bradford proposes that "Her well crafted lyrics, expressive voice and ability to communicate without too many of the standard evangelical clichés make Lindsay McCaul one of the most promising artists on today's CCM scene." Grace S. Aspinwall advises for CCM Magazine that "McCaul shows tremendous growth in both her songwriting and her vocal control on this, her latest effort... Though some clichés remain... she is one to reckon with as she continues her upward trajectory."

On behalf of New Release Tuesday, Kevin Davis exclaims that "This is a great new collection of heartfelt and inspirational songs about the journey of life we are all on as pilgrims, keeping our eyes on the prize of eternal life in Jesus Christ."Writing of Christian Music Review, Laura Chambers describes that "Lindsay McCaul has bravely come out of her struggles with a fresh faith, renewed hope, these songs which encourage us towards the same perspective... Pairing life lessons with the tender and whimsical tones of these songs, it’s the perfect combination to whisper the truth past your ears into your heart." Lindsay Williams reveals for The Sound Opinion that "The songs on One More Step should be savored and soaked in." On behalf of Louder Than the Music, Jono Davies explains that "It takes a top quality songwriter to do that and still make the songs sound catchy... Lindsay does that on this wonderful album." Writing for 365 Days of Inspiring Media, Jonathan Andre compliments that "Well done Lindsay for such a powerful and enjoyable album!"

Michael Dalton from The Phantom Tollbooth says "is a brilliant combination of authentic faith and sophisticated pop." AllMusic

Norway in the Eurovision Song Contest 1999

Norway competed in the Eurovision Song Contest 1999, represented by Stig van Eijk with the song "Living My Life Without You". The song was chosen as the Norwegian entry after winning the Melodi Grand Prix 1999 contest. Norsk rikskringkasting held a national final to select the Norwegian entry for the 1999 Eurovision Song Contest; the final was held on 27 February 1999 at the NRK TV studios in Oslo, hosted by Rune Gokstad and Øystein Bache. 8 songs competed, with the winner decided by a combination of regional jury voting. On the night of Eurovision, held on 29 May in Jerusalem, Stig van Eijk performed "Living My Life Without You" eighth in the running order, following Turkey and preceding Denmark. At the close of the voting, Stig had received 35 points, placing 14th in a field of 23. Eurovision Song Contest 1999 Norway in the Eurovision Song Contest Melodi Grand Prix Norwegian National Final 1999