Management of complex structural engineering objects in a relational framework

1990 ◽  
Vol 6 (2) ◽  
pp. 81-92 ◽  
Author(s):  
Kincho H. Law ◽  
Thierry Barsalou ◽  
Gio Wiederhold
Keyword(s):  
Structural Engineering ◽  
Complex Structural ◽  
Relational Framework

scholarly journals Architecture of the sperm whale forehead facilitates ramming combat

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1895 ◽  
Author(s):  
Olga Panagiotopoulou ◽  
Panagiotis Spyridis ◽  
Hyab Mehari Abraha ◽  
David R. Carrier ◽  
Todd C. Pataky
Keyword(s):  
Connective Tissue ◽  
Structural Engineering ◽  
Sperm Whale ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Moby Dick ◽  
Unique Structure ◽  
Complex Structural ◽  
Von Mises ◽  
Von Mises Stresses

Herman Melville’s novelMoby Dickwas inspired by historical instances in which large sperm whales (Physeter macrocephalus L.) sank 19th century whaling ships by ramming them with their foreheads. The immense forehead of sperm whales is possibly the largest, and one of the strangest, anatomical structures in the animal kingdom. It contains two large oil-filled compartments, known as the “spermaceti organ” and “junk,” that constitute up to one-quarter of body mass and extend one-third of the total length of the whale. Recognized as playing an important role in echolocation, previous studies have also attributed the complex structural configuration of the spermaceti organ and junk to acoustic sexual selection, acoustic prey debilitation, buoyancy control, and aggressive ramming. Of these additional suggested functions, ramming remains the most controversial, and the potential mechanical roles of the structural components of the spermaceti organ and junk in ramming remain untested. Here we explore the aggressive ramming hypothesis using a novel combination of structural engineering principles and probabilistic simulation to determine if the unique structure of the junk significantly reduces stress in the skull during quasi-static impact. Our analyses indicate that the connective tissue partitions in the junk reduce von Mises stresses across the skull and that the load-redistribution functionality of the former is insensitive to moderate variation in tissue material parameters, the thickness of the partitions, and variations in the location and angle of the applied load. Absence of the connective tissue partitions increases skull stresses, particularly in the rostral aspect of the upper jaw, further hinting of the important role the architecture of the junk may play in ramming events. Our study also found that impact loads on the spermaceti organ generate lower skull stresses than an impact on the junk. Nevertheless, whilst an impact on the spermaceti organ would reduce skull stresses, it would also cause high compressive stresses on the anterior aspect of the organ and the connective tissue case, possibly making these structures more prone to failure. This outcome, coupled with the facts that the spermaceti organ houses sensitive and essential sonar producing structures and the rostral portion of junk, rather than the spermaceti organ, is frequently a site of significant scarring in mature males suggest that whales avoid impact with the spermaceti organ. Although the unique structure of the junk certainly serves multiple functions, our results are consistent with the hypothesis that the structure also evolved to function as a massive battering ram during male-male competition.

scholarly journals Architecture of the sperm whale forehead facilitates ramming combat

2015 ◽  
Author(s):  
Olga Panagiotopoulou ◽  
Panagiotis Spyridis ◽  
Hyab Mehari Abraha ◽  
David R Carrier ◽  
Todd C Pataky
Keyword(s):  
Connective Tissue ◽  
Stress Reduction ◽  
Structural Engineering ◽  
Sperm Whale ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Stress Concentrations ◽  
Moby Dick ◽  
Unique Structure ◽  
Complex Structural

Herman Melville’s novel Moby Dick was inspired by historical instances in which large sperm whales (Physeter macrocephalus L.) sank 19th century whaling ships by ramming them with their foreheads. The immense forehead of sperm whales is possibly the largest, and one of the strangest, anatomical structures in the animal kingdom. It contains two large oil-filled compartments, known as the “spermaceti organ” and “junk”, that constitute up to one-quarter of body mass and extend one-third of the total length of the whale. Recognized as playing an important role in echolocation, previous studies have also attributed the complex structural configuration of the spermaceti organ and junk to acoustic sexual selection, acoustic prey debilitation, buoyancy control, and aggressive ramming. Of these additional suggested functions, ramming remains the most controversial, and the potential mechanical roles of the structural components of the spermaceti organ and junk in ramming remain untested. Here we explore the aggressive ramming hypothesis using a novel combination of structural engineering principles and probabilistic simulation to determine if the unique structure of the junk significantly reduces stress in the skull during quasi-static impact. Our analyses indicate that the connective tissue partitions within the junk reduce stress across the skull during impact; stress reduction is greatest in the anterior aspect of the skull; and removal of the connective tissue partitions increases stress concentrations on the tip of the skull, possibly making it prone to fracture. Although the unique structure of the junk certainly serves multiple functions, our results are consistent with the hypothesis that the structure also evolved to function as a massive battering ram during male-male competition.

scholarly journals Architecture of the sperm whale forehead facilitates ramming combat

2015 ◽  
Author(s):  
Olga Panagiotopoulou ◽  
Panagiotis Spyridis ◽  
Hyab Mehari Abraha ◽  
David R Carrier ◽  
Todd C Pataky
Keyword(s):  
Connective Tissue ◽  
Stress Reduction ◽  
Structural Engineering ◽  
Sperm Whale ◽  
Physeter Macrocephalus ◽  
Sperm Whales ◽  
Stress Concentrations ◽  
Moby Dick ◽  
Unique Structure ◽  
Complex Structural

Herman Melville’s novel Moby Dick was inspired by historical instances in which large sperm whales (Physeter macrocephalus L.) sank 19th century whaling ships by ramming them with their foreheads. The immense forehead of sperm whales is possibly the largest, and one of the strangest, anatomical structures in the animal kingdom. It contains two large oil-filled compartments, known as the “spermaceti organ” and “junk”, that constitute up to one-quarter of body mass and extend one-third of the total length of the whale. Recognized as playing an important role in echolocation, previous studies have also attributed the complex structural configuration of the spermaceti organ and junk to acoustic sexual selection, acoustic prey debilitation, buoyancy control, and aggressive ramming. Of these additional suggested functions, ramming remains the most controversial, and the potential mechanical roles of the structural components of the spermaceti organ and junk in ramming remain untested. Here we explore the aggressive ramming hypothesis using a novel combination of structural engineering principles and probabilistic simulation to determine if the unique structure of the junk significantly reduces stress in the skull during quasi-static impact. Our analyses indicate that the connective tissue partitions within the junk reduce stress across the skull during impact; stress reduction is greatest in the anterior aspect of the skull; and removal of the connective tissue partitions increases stress concentrations on the tip of the skull, possibly making it prone to fracture. Although the unique structure of the junk certainly serves multiple functions, our results are consistent with the hypothesis that the structure also evolved to function as a massive battering ram during male-male competition.

scholarly journals Application of Analytic Databases to Support Decision Making in Structural Engineering / Zastosowanie Analitycznych Baz Danych Przy Podejmowaniu Decyzji W Obszarze Budownictwa Ladowego

2010 ◽  
Vol 56 (2) ◽  
pp. 173-192
Author(s):  
J. Szelka ◽  
Z. Wrona
Keyword(s):  
Decision Making ◽  
Information Systems ◽  
Structural Engineering ◽  
Information Gathering ◽  
Transactional Databases ◽  
Decision Making Processes ◽  
Multidimensional Information ◽  
Complex Structural ◽  
Engineering Projects ◽  
Support Decision Making

Abstract Complex structural engineering projects that involve information-gathering and decision-making processes need to be approached with appropriate systems and tools. As transactional databases are found to be insufficient for this purpose, engineers are adopting multidimensional information systems that have been successfully used in other areas of management, especially business

Revisiting the Roles of Structural Engineering Design Professionals under Their Increasing Risks and Associated Liabilities

2020 ◽  
Author(s):  
Carla Ghannoum ◽  
Mohamed-Asem Abdul-Malak ◽  
Mounir Mabsout
Keyword(s):  
Engineering Design ◽  
Structural Engineering

Seeking Magneto-Structural Correlations in Easily Tailored Pentagonal Bipyramid Dy(III) Single-Ion Magnets

2019 ◽  
Author(s):  
Guo-Zhang Huang ◽  
Ze-Yu Ruan ◽  
Jie-Yu Zheng ◽  
Yan-Cong Chen ◽  
Si-Guo Wu ◽  
...  
Keyword(s):  
Single Molecule ◽  
Structural Engineering ◽  
Magnetic Hysteresis ◽  
Sweep Rate ◽  
Coordination Bond ◽  
Pentagonal Bipyramid ◽  
Single Molecule Magnets ◽  
Crystal Field Theory ◽  
Bond Angles ◽  
Axial Coordination

<p><a></a>Controlling molecular magnetic anisotropy via structural engineering is delicate and fascinating, especially for single-molecule magnets (SMMs). Herein a family of dysprosium single-ion magnets (SIMs) sitting in pentagonal bipyramid geometry have been synthesized with the variable-size terminal ligands and counter anions, through which the subtle coordination geometry of Dy(III) can be finely tuned based on the size effect. The effective energy barrier (Ueff) successfully increases from 439 K to 632 K and the magnetic hysteresis temperature (under a 200 Oe/s sweep rate) raises from 11 K to 24 K. Based on the crystal-field theory, a semi-quantitative magneto-structural correlation deducing experimentally for the first time is revealed that the Ueff is linearly proportional to the structural-related value S2<sup>0</sup> corresponding to the axial coordination bond lengths and the bond angles. Through the evaluation of the remanent magnetization from hysteresis, quantum tunneling of magnetization (QTM) is found to exhibit negative correlation with the structural-related value S<sub>tun</sub> corresponding to the axial coordination bond angles.<br></p>

Strongly Coupled Redox-Linked Conformational Switching at the Active Site of the Non-Heme Iron-Dependent Dioxygenase, TauD

2019 ◽  
Author(s):  
Christopher John ◽  
Greg M. Swain ◽  
Robert P. Hausinger ◽  
Denis A. Proshlyakov
Keyword(s):  
Active Site ◽  
Structural Model ◽  
Heme Iron ◽  
Chemical Transformations ◽  
Experimental Conditions ◽  
Strongly Coupled ◽  
Non Heme Iron ◽  
Reversible Redox ◽  
Wide Range ◽  
Complex Structural

2-Oxoglutarate (2OG)-dependent dioxygenases catalyze C-H activation while performing a wide range of chemical transformations. In contrast to their heme analogues, non-heme iron centers afford greater structural flexibility with important implications for their diverse catalytic mechanisms. We characterize an <i>in situ</i> structural model of the putative transient ferric intermediate of 2OG:taurine dioxygenase (TauD) by using a combination of spectroelectrochemical and semi-empirical computational methods, demonstrating that the Fe (III/II) transition involves a substantial, fully reversible, redox-linked conformational change at the active site. This rearrangement alters the apparent redox potential of the active site between -127 mV for reduction of the ferric state and 171 mV for oxidation of the ferrous state of the 2OG-Fe-TauD complex. Structural perturbations exhibit limited sensitivity to mediator concentrations and potential pulse duration. Similar changes were observed in the Fe-TauD and taurine-2OG-Fe-TauD complexes, thus attributing the reorganization to the protein moiety rather than the cosubstrates. Redox difference infrared spectra indicate a reorganization of the protein backbone in addition to the involvement of carboxylate and histidine ligands. Quantitative modeling of the transient redox response using two alternative reaction schemes across a variety of experimental conditions strongly supports the proposal for intrinsic protein reorganization as the origin of the experimental observations.

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