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A Brief History of Engineering
Published in Diane P. Michelfelder, Neelke Doorn, The Routledge Handbook of the Philosophy of Engineering, 2020
The most spectacular of ancient projects were the ziggurats and pyramids that dominated the horizon wherever they were built. In ancient Babylon, the ziggurat Etemenanki rose 300 feet above the plain, faced with enameled brick and the inspiration for the biblical story of the Tower of Babel, where God confused the languages of the laborers so they could no longer complete what was described as humans’ attempt to become gods themselves by reaching the heavens. The Great Pyramid Cheops, or Khufu, the largest of all pyramids and set at Giza, west of modern Cairo, was a project of the consolidated power of Old Kingdom Egypt; it stood more than 480 feet high, measured 756 feet along one side of its square foundation, and required the placing of more than 2 million blocks of two-ton-plus stone, raised by the muscle power of thousands of laborers along enormous ramps. The bulk was made from local limestone, supplemented with finer limestone for the face. These ancient projects serve as evidence of design and management on a vast scale. The Great Pyramid required people to design it, survey the site and the stone quarries, build roads and ramps for transporting and placing the stone, and provide for the daily needs of a very large workforce. It was the work of a consolidated and wealthy power.
UNESCO World Heritage Sites, International Union of Geological Sciences and Heritage Stone Subcommission
Published in Gurmeet Kaur, Sakoon Singh, Anuvinder Ahuja, Noor Dasmesh Singh, Natural Stone and World Heritage, 2020
Gurmeet Kaur, Sakoon Singh, Anuvinder Ahuja, Noor Dasmesh Singh
Giza Necropolis, a UNESCO World Heritage Site, exists on the Giza plateau and dates from 2550 to 2490 BCE. The complex consists of the Great Pyramid of Giza, the Pyramid of Khafre, the Pyramid of Menkaure and the Great Sphinx of Giza (www.nationalgeographic.com/archaeology-and-history/archaeology/giza-pyramids/). Limestone was used for the exterior of the pyramids; granite was used for burials; basalt was used for floors of temples and tombs; travertine or Egyptian alabaster, a type of limestone, was used for making sacred tools for mummification; and porphyry was used to make the high columns and wall linings.
Spiritual life and life after death in the undergrounds of ancient Iran
Published in Daniele Peila, Giulia Viggiani, Tarcisio Celestino, Tunnels and Underground Cities: Engineering and Innovation meet Archaeology, Architecture and Art, 2020
In the past, it was believed that mountains were one of God’s first creations and in some ancient cultures mountains were considered holy and the place of the Gods. The Ark of Noah came to rest on a mountain once floodwater receded. The Ten Commandments were delivered to Moses on Mount Horeb. Abraham attempted to sacrifice his son on a mountain. Prophet Mohammed meditated on a mountain near Mecca and his first revelation was received in the cave of Hira. In ancient Greek religion and mythology it is believed that the major deities (the twelve Olympians) resided atop Mount Olympus. Others believed that the gods were in heaven and hence built their temples or tombs in higher ground to be closer to them. The most important temples constructed based on this idea are Ziggurats. These massive structures had the form of a terraced step pyramid of successively receding levels. The purpose of these structures is to get the temple closer to heavens. The Chogha Zanbil Ziggurat in Iran is one such structure that was built about 1250 B.C. during the Elamite era mainly to honor the God Inshushinak (the protector of Susa). The Egyptians built the tombs of Pharaoh’s in form of pyramid buildings representing mounds which were designed to serve as stairways by which the soul of deceased pharaohs could ascend to the heavens.
Improving the operating time of the multi slope shape solar still
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2021
S Arun Kumar, P Suresh Mohan Kumar
The SBMSSS is fabricated with basin, insulation, transparent plate, level indicator, and solenoid valve. Two SBMSSS and one solar pond are fabricated for experiments. The SBMSSS basin is made of a stainless-steel sheet and in 0.5 m X 0.5 m square shape. The inner side of the basin is coated with black paint. The outer side of the basin is surrounded by 0.02 m thick thermocol as insulation. The multi slopes are formed by a square pyramid shape. The square pyramid shape transparent plate is placed above the square basin. The 0.004 m glass is used as the transparent plate. The title angle of the transparent plate is 30°. The level indicator is placed inside the square basin for maintaining the constant 0.02 m depth of brine. The solenoid valve on and off is actuated by the level indicator signal. The solar pond is constructed by a transparent plate and a copper coil is placed inside it. The glass is used as a transparent plate. The 0.006 m thickness of the transparent plate used in the solar pond. The dimensions of the solar pond are fabricated as 0.75 m X 0.3 m bottom area, 1 m X 0.5 m top area, and 0.3 m height. The 0.005 m diameter copper coil.
Syntheses, structures, photoluminescence, and near-infrared of pentanuclear Tb(III), Yb(III) dibenzoylmethane complexes
Published in Inorganic and Nano-Metal Chemistry, 2021
X-ray crystallographic analysis reveals that complexes 1 and 2 crystallize in the tetragonal space group P4/n. All Ln sites are six-coordinate. The geometry at each site is based on octahedral. Each lanthanide atom site has local, but non-crystallographic, C4v symmetry. The lanthanide atoms adopt the expected square-based pyramidal arrangement. Each triangular face of the square pyramid is capped by one μ3-O moiety. In the square-based face, four lanthanide atoms are linked by one μ4-O atom (from OH). A total of 10 peripheral ligands surround the Ln5 cluster core. The ligand shows two different coordination modes. Six ligands are terminally chelating and four are bridging chelating, bonding to two metal ions that belong to the base of the polyhedron. The apical lanthanide, which lies on a 4-fold symmetry axis, is bonded to two disordered chelate ligands (Figure 2).
Stability and electronic properties of Rh-doped ruthenium clusters and their interaction with NH3 molecule
Published in Molecular Physics, 2020
Mouhssin Boulbazine, Abdel-Ghani Boudjahem, Salem Chaguetmi, Abdelhak Karaman
For Ru8Rh cluster, the capped cubic structure (8a) with high spin multiplicity (10A′) and CS symmetry is considered as the most stable configuration. The second isomer is a fusion of one prism and three square pyramids (8b) with C2V symmetry. The geometry 8c is a combination of two prisms with the same symmetry that the geometry 8b. Its energy is 0.92 eV higher than the geometry 8b. The geometry 8d is formed from the combination of one prism and bicapped square pyramid with C2V symmetry, and the Rh atom is situated at the apex of the square pyramid. The tetra-capped trigonal bipyramid geometry (8e) with CS symmetry has also been predicted as the low energy configuration. The tricapped octahedron configuration (8f) with CS symmetry is obtained in our optimisations, and its energy is higher than the geometry 8e by only 0.15 eV.