An adapted-mixed fem procedure for calculating the three-dimensional elastoplastic state of structural elements

1993 ◽  
Vol 25 (9) ◽  
pp. 676-687
Author(s):  
B. Z. Kruk ◽  
S. A. Romanchenko ◽  
A. E. Ponomarenko ◽  
S. �. Umanskii
Keyword(s):  
Three Dimensional ◽  
Structural Elements ◽  
Elastoplastic State ◽  
Mixed Fem

Designing TIMP (tissue inhibitor of metalloproteinases) variants that are selective metalloproteinase inhibitors

2003 ◽  
Vol 70 ◽  
pp. 201-212 ◽  
Author(s):  
Hideaki Nagase ◽  
Keith Brew
Keyword(s):  
Three Dimensional ◽  
Therapeutic Interventions ◽  
Tissue Inhibitors Of Metalloproteinases ◽  
Structural Basis ◽  
Structural Elements ◽  
Ridge Structure ◽  
Extracellular Matrix Components ◽  
Metalloproteinase Inhibitors ◽  
The Matrix ◽  
A Disintegrin And Metalloproteinase

The tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors of the matrix metalloproteinases (MMPs), enzymes that play central roles in the degradation of extracellular matrix components. The balance between MMPs and TIMPs is important in the maintenance of tissues, and its disruption affects tissue homoeostasis. Four related TIMPs (TIMP-1 to TIMP-4) can each form a complex with MMPs in a 1:1 stoichiometry with high affinity, but their inhibitory activities towards different MMPs are not particularly selective. The three-dimensional structures of TIMP-MMP complexes reveal that TIMPs have an extended ridge structure that slots into the active site of MMPs. Mutation of three separate residues in the ridge, at positions 2, 4 and 68 in the amino acid sequence of the N-terminal inhibitory domain of TIMP-1 (N-TIMP-1), separately and in combination has produced N-TIMP-1 variants with higher binding affinity and specificity for individual MMPs. TIMP-3 is unique in that it inhibits not only MMPs, but also several ADAM (a disintegrin and metalloproteinase) and ADAMTS (ADAM with thrombospondin motifs) metalloproteinases. Inhibition of the latter groups of metalloproteinases, as exemplified with ADAMTS-4 (aggrecanase 1), requires additional structural elements in TIMP-3 that have not yet been identified. Knowledge of the structural basis of the inhibitory action of TIMPs will facilitate the design of selective TIMP variants for investigating the biological roles of specific MMPs and for developing therapeutic interventions for MMP-associated diseases.

A test of airborne, side-looking synthetic-aperture radar in central Newfoundland for geological reconnaissance

1991 ◽  
Vol 28 (2) ◽  
pp. 257-265 ◽  
Author(s):  
D. F. Graham ◽  
D. R. Grant
Keyword(s):  
Surface Roughness ◽  
Synthetic Aperture Radar ◽  
Three Dimensional ◽  
Synthetic Aperture ◽  
Structural Elements ◽  
Terrain Classification ◽  
Regional Trends ◽  
Valuable Complement ◽  
Wide Swath ◽  
Aperture Radar

Side-looking, C-band synthetic-aperture radar (SAR) penetrates cloud and fog, and operates day or night, to produce pseudo-three-dimensional terrain images with enhanced topography and surface roughness. The images, which have a 20 m resolution and cover large areas, have been used to map the regional trends, patterns of lineaments, and terrain types over a 6200 km2 area of complex lithology, structure, and drift cover. Four lineament classes are differentiated. Glacial trends are clear, and bedrock structures (faults, fractures, joints, foliation, and folded bedding) with relief expression at the surface show through the drift as lineaments. They accurately reproduce most known features when compared with bedrock and Quatenary geology maps. Hitherto unrecognized structural elements are revealed. Tones and textures reflect minute surface roughness variations useful in terrain classification. SAR wide-swath-mode imagery is thus a valuable complement to aerial photography, and is superior in revealing hummocky moraine, ribbed moraine, boulder fields and stony till. Wider use of this imagery is encouraged.

scholarly journals Condensation method in practical modal analysis of hull vibration with application of 3D FE model

2019 ◽  
pp. 162-169
Author(s):  
Valeriy Sutyrin
Keyword(s):  
Modal Analysis ◽  
Three Dimensional ◽  
Element Model ◽  
Fe Model ◽  
Structural Elements ◽  
Natural Vibrations ◽  
Condensation Method ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Analytical Approaches

This paper gives modal analysis results for mid-body of a refrigerator carrier ship by means of combined three-dimensional finite-element model with 1.5 million DOF. The study estimates the error of modal analysis for the ship structure if its boundary conditions are specified in advance, i.e. approximately, as well as analyses the gain in time offered by structuring the analytical model as per reduction (condensation) method. Analytical approaches thus transformed can be successfully applied in filtering lower frequencies and modes of natural vibrations for structural elements and joints of hull in the direct vicinity of exciting force application points.

scholarly journals POSSIBLE DEFECTS IN WOOD, WOOD PARAMETERS VARIABILITY AND SOME OF ITS INFLUENCE ON QUALITY OF BUILDING STRUCTURE

2015 ◽  
Vol 7 (2) ◽  
pp. 67-80
Author(s):  
Jaroslaw Malesza
Keyword(s):  
Three Dimensional ◽  
Residential Building ◽  
Theoretical Description ◽  
Construction Technology ◽  
Structural Elements ◽  
Require Time ◽  
Factory Production ◽  
3D Elements ◽  
Load Increase

Paper specifies the wood-framed with sheathing construction including phases of realization and exploitation. Methods of investigation based on practice and theory has been employed where practical identification of processes and their phases were presented with theoretical description of structure deformation within the exploitation period. Obtained results of investigations are presented in the form of technologic and mechanic of structure diagrams for buildings with adequate algorithms of analysis. Paper presents practical systematic of construction stages, technological problems and hazards in respect of loading and construction technology with method of computation of vertical deformations of building. Paper presents evaluation of contribution of wood defects in response to loading in the wood-framed residential building in exploitation process. Location of knots, allocation of pith in the elements cross section, defects of slope of grain and influence of moisture decreasing is examined in the paper. The wood-framed with sheathing in the form of large panel or modular three dimensional 3D elements are the most often used technology. This kind of buildings are actually constructed up to four story as a multifamily or varying universal buildings like school, kid-garden or offices. Low dead load from 0.30 to 1.00 kN/m2 and its favorable proportion to the live load increase energy saving factor in realization and within the exploitation time. Low own weight of structure enables complete prefabrication of wall, floor and roof panels, improving quality of construction and shortening time of construction. Process of prefabrication, wide assortment and variety of factory production does not require time consuming processes and complicated moulds or shuttering indispensable in precast RC structural elements.

scholarly journals Hemp Cables, a Sustainable Alternative to Harmonic Steel for Cable Nets

Resources ◽  
2018 ◽  
Vol 7 (4) ◽  
pp. 70 ◽  
Author(s):  
Alberto Viskovic
Keyword(s):  
Three Dimensional ◽  
Structural Response ◽  
Building Design ◽  
Structural Elements ◽  
Nonlinear Analyses ◽  
Hyperbolic Paraboloid ◽  
Materials Engineering ◽  
Recent Developments ◽  
Vertical Displacements ◽  
Cable Nets

Recent developments in the field of materials engineering have allowed for the use of natural materials for common structural elements, instead of traditional materials, such as steel or concrete. In this context, hemp is a very interesting material for structural building design. This paper proposes the use of hemp cables for roofs with hyperbolic paraboloid cable nets, which sees the use of a sustainable material for structure, thus having a very low environmental impact, in terms of structural thickness and amount of material. The paper discusses five different plan sizes and two different hyperbolic paraboloid surface radius of curvatures. The cable traction, which gives the cable net stiffness, was varied in order to give a parametric database of structural response. Three dimensional geometrically nonlinear analyses were carried out on different geometries (i.e., 10), cable net stiffnesses (i.e., 8), and materials (i.e., 2). Traditional harmonic steel and hemp cables are compared, in terms of vertical displacements and natural periods under dead and permanent loads.

A review of 3D concrete printing systems and materials properties: current status and future research prospects

2018 ◽  
Vol 24 (4) ◽  
pp. 784-798 ◽  
Author(s):  
Suvash Chandra Paul ◽  
Gideon P.A.G. van Zijl ◽  
Ming Jen Tan ◽  
Ian Gibson
Keyword(s):  
Three Dimensional ◽  
Current Status ◽  
Future Research ◽  
Structural Elements ◽  
Construction Time ◽  
Content Type ◽  
Three Dimensional Printing ◽  
Materials Research ◽  
Printing System ◽  
Dimensional Printing

Purpose Three-dimensional printing of concrete (3DPC) has a potential for the rapid industrialization of the housing sector, with benefits of reduced construction time due to no formwork requirement, ease of construction of complex geometries, potential high construction quality and reduced waste. Required materials adaption for 3DPC is within reach, as concrete materials technology has reached the point where performance-based specification is possible by specialists. This paper aims to present an overview of the current status of 3DPC for construction, including existing printing methods and material properties required for robustness of 3DPC structures or structural elements. Design/methodology/approach This paper has presented an overview of three categories of 3DPC systems, namely, gantry, robotic and crane systems. Material compositions as well as fresh and hardened properties of mixes currently used for 3DPC have been elaborated. Findings This paper presents an overview of the state of the art of 3DPC systems and materials. Research needs, including reinforcement in the form of bars or fibres in the 3D printable cement-based materials, are also addressed. Originality/value The critical analysis of the 3D concrete printing system and materials described in this review paper is original.

scholarly journals Structural elements regulating the photochromicity in a cyanobacteriochrome

2020 ◽  
Vol 117 (5) ◽  
pp. 2432-2440 ◽  
Author(s):  
Xiuling Xu ◽  
Astrid Höppner ◽  
Christian Wiebeler ◽  
Kai-Hong Zhao ◽  
Igor Schapiro ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Structural Data ◽  
Spectral Shift ◽  
Structural Elements ◽  
Systematic Analysis ◽  
X Ray ◽  
Peculiar Form ◽  
Out Of Plane ◽  
Distinct Features ◽  
Protein Environment

The three-dimensional (3D) crystal structures of the GAF3 domain of cyanobacteriochrome Slr1393 (Synechocystis PCC6803) carrying a phycocyanobilin chromophore could be solved in both 15-Z dark-adapted state, Pr, λmax = 649 nm, and 15-E photoproduct, Pg, λmax = 536 nm (resolution, 1.6 and 1.86 Å, respectively). The structural data allowed identifying the large spectral shift of the Pr-to-Pg conversion as resulting from an out-of-plane rotation of the chromophore’s peripheral rings and an outward movement of a short helix formed from a formerly unstructured loop. In addition, a third structure (2.1-Å resolution) starting from the photoproduct crystals allowed identification of elements that regulate the absorption maxima. In this peculiar form, generated during X-ray exposition, protein and chromophore conformation still resemble the photoproduct state, except for the D-ring already in 15-Z configuration and tilted out of plane akin the dark state. Due to its formation from the photoproduct, it might be considered an early conformational change initiating the parental state-recovering photocycle. The high quality and the distinct features of the three forms allowed for applying quantum-chemical calculations in the framework of multiscale modeling to rationalize the absorption maxima changes. A systematic analysis of the PCB chromophore in the presence and absence of the protein environment showed that the direct electrostatic effect is negligible on the spectral tuning. However, the protein forces the outer pyrrole rings of the chromophore to deviate from coplanarity, which is identified as the dominating factor for the color regulation.

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