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Fused deposition modelling (FDM) is a type of additive manufacturing technology which is being used to manufacture prototypes and functional parts. However, the volumetric shrinkage limits the functionality of the manufactured prototypes. Accurately predicting the volumetric shrinkage will diversify the applicability of this manufacturing technology because the volumetric error could be eliminated at the product specification/development stage. Also, the volumetric shrinkage prediction in the process will enable for an in-process adjustment and proper selection of the machine setting. This work involves using the layer thickness, orientation angle and structural geometry as parameters to predict the volumetric shrinkage. The prediction of the shrinkage in the FDM prototypes along both the XZ and YZ-axis was done using ANFIS. The experimental test result validates the effectiveness of the constructed ANFIS model, which has about 3.15% average prediction error. The comparison between the manufactured hollow shapes also gives the best input settings for manufacturing of the hollows in the components.

In this paper, laboratory prepared azo derivative 2-[(4-Formyl phenyl) azo]-4,5-diphenyl imidazole (FPAPI) has been used as complexing agents for extraction Pb(II) and Cd(II) ions from aqueous solutions. Spectroscopy study was at ?max=533nm for ion pair complex of Pb(II) and ?max=543nm for ion pair complex of Cd(II) and all effective parameters on the extraction process were also studied. The optimum pH results for giving higher extraction efficiency of Pb(II) and Cd(II) were 8 and 9 respectively. In addition to other parameters such as shaking time, thermodynamics, an organic solvent, interferences, electrolytes, the paper has adopted different methods to determine the most feasible structural geometry of extracted ion-pair complex of [1:1]2+, anion, [Pb-FPAPI]2+, 2NO3-, [Cd-FPAPI]2+, 2NO3-.

Gymnastics, a high-impact weight-bearing physical activity, has been shown to be highly osteogenic. Previously in this cohort, bone mass development (bone mineral content accrual [BMC]) was shown to be positively associated with low-level (recreational) gymnastics exposure (1 to 2 hours per week); however, BMC is only one single component of bone strength. Bone strength is influenced not only by bone mineralization but also bone geometry, bone architecture, and the imposing loads on the bone. The aim of this study was to investigate whether low-level gymnastics training influenced the estimated structural geometry development at the proximal femur. A total of 165 children (92 gymnasts and 73 non-gymnasts) between the ages of 4 and 6 years were recruited into this study and assessed annually for 4 years. During the 4 years, 64 gymnasts withdrew from the sport and were reclassified as ex-gymnasts. A dual-energy X-ray absorptiometry (DXA) image of each child's hip was obtained. Values of cross-sectional area (CSA), section modulus (Z), and cortical thickness (CT) at the narrow neck (NN), intertrochanter (IT), and shaft (S) were estimated using the hip structural analysis (HSA) program. Multilevel random-effects models were constructed and used to develop bone structural strength development trajectories (estimate ± SEE). Once the confounders of body size and lifestyle were controlled, it was found that gymnasts had 6% greater NN CSA than non-gymnasts controls (0.09 ± 0.03 cm(2) , p < 0.05), 7% greater NN Z (0.04 ± 0.01 cm(3) , p < 0.05), 5% greater IT CSA (0.11 ± 0.04 cm(3) , p < 0.05), 6% greater IT Z (0.07 ± 0.03 cm(3) , p < 0.05), and 3% greater S CSA (0.06 ± 0.03 cm(3) , p < 0.05). These results suggest that early exposure to low-level gymnastics participation confers benefits related to geometric and bone architecture properties during childhood and, if maintained, may improve bone health in adolescence and adulthood.

[1] Contrasting models of upper crustal shortening versus lower crustal flow have been proposed to explain the formation of thickened crust in the Longmen Shan (LMS), eastern Tibetan Plateau (TP) margin. These models require different structural kinematics along the LMS, whose structural geometry is defined by three parallel NW-dipping fault zones. From foreland (southeast) to hinterland (northwest), they are the Guanxian-Anxian Fault, Yingxiu-Beichuan Fault (YBF), and Wenchuan-Maowen Fault (WMF). Newly derived and previously published low-temperature thermochronology data from the LMS were synthesized to constrain the spatial exhumation and test previous models. The results show that (1) exhumation increases abruptly across the range-bounding YBF, suggesting the fault being the main thrust boundary between the LMS and the Sichuan Basin to the east; (2) Younger Late Cenozoic cooling ages are found on the hinterland WMF, where a dichotomy of ages on the hanging wall versus footwall suggests Late Cenozoic thrust activity; and (3) toward the hinterland to the west, exhumation rates decrease twofold over a distance of ~30–40 km. This exhumation pattern indicates a westward decrease of tectonic uplift, providing the regional topography approached a steady state, whereby exhumation is in balance with tectonic uplift. The observed exhumation estimates support an upper crustal configuration where thrusts in the LMS merge gradually into a gentle detachment seated at a depth of ~20–30 km. Results of this study support a revised upper crustal thrusting model.

The interfibre joint is one of the key elements in creating the strength of self-binding fibrous materials such as paper and board. In order evaluate the strength properties of interfibre joints using direct measurements, a greater understanding on how the mode of loading influences the results is desirable. The methods reported in the literature do not in general distinguish between the contributions of normal and shear stresses in the bonded region. This paper presents a numerical analysis procedure, based on the finite element method, for evaluating interfibre joint strength measurements in terms of the normal, shear, and moment loading components during testing. The target is to estimate the resultant forces and moments, that acts in the interfibre joint region at rupture, of Kraft pulp interfibre joints tested under two principally different modes of loading. The results show that for a typical interfibre joint test, modes of loading other than pure shear cannot, in general, be neglected, and are strongly dependent on the structural geometry of the fibre–fibre crosses. In addition, the resultant forces and moments were scaled in terms of the interface area and the twisting and bending resistance of the interface approximated as an ellipse to account for differences in interface area between the measurements. These scaled resultants were used to quantify how the mode of loading influences the relation between the amount of normal stress and the amount of shear stress that develop in the interfibre joint.

The 2008 Mw 7.9 Wenchuan earthquake is a consequence of ongoing India-Tibet collision and reflects the growth of the Longmen Shan fold-and-thrust belt. In this paper, we present new constraints on the deformation mechanism of the Longmen Shan fold-and-thrust belt, by comparing the physical models to the example of the Longmen Shan fold-and-thrust belt. The result indicates that the deformation mechanism of the belt is mainly dominated by the pre-Sinian layer, whereas locally is controlled by the Lower Triassic layer, such as the Longquan anticline. In addition, we discuss the deformation style of the Longquan anticline various along strike, based on the seismic reflection data, interpretations of structural cross-sections and field observations, as well as physical modeling. The sandbox modeling suggests that the deformation of the central segment of Longquan anticline is likely controlled by higher displacement rate, higher erosion and lower sedimentation, which is in contrast with the southern and northern segment. Moreover, the structural geometry of the central segment of Longquan anticline is more complex than the end-member models of fault-related folds, which is mainly controlled by pure-shear wedge fault-bend fold and bounded by west-verging thrust fault. Combining the studies of the structural geometry, deformation mechanism, and previous studies, we infer that the Longquan anticline is active and potentially seismogenic. Therefore, a quantitative re-evaluation of seismic hazard in Longquan anticline and adjacent area directly beneath the densely populated Sichuan basin is urgently needed.

An efficient and stereoselective procedure has been described for the synthesis of a series of β-enaminoesters and β-enaminones by vanadium(IV) acetylacetonate [VO(acac)2] catalyzed reaction of β-ketoesters and 1,3-diketones with both aliphatic and aromatic amines. X-ray crystallographic studies of some representative compounds corroborate two types of structural geometry formed by inter-molecular as well as intra-molecular hydrogen bonds.

The 2008 Ms 8.0 Wenchuan earthquake of China ruptured two large faults along the Beichuan-Yingxiu thrust belt and the Pengguan thrust belt at the Longmen Shan Orogenic belt, eastern margin of the Tibetan Plateau. Our study focused on the structural geometry at the Pengguan thrust belt located at the frontal zone of the Central Longmen Shan. In this paper, in order to identify the co-seismic fault at the Pengguan thrust belt many 2-D/3-D seismic reflection profiles have been interpreted by integrating with the geological maps, drilling data, DEM data and the surface ruptures. The results show that there were three major faults and other branch faults at the Pengguan thrust belt. The major faults have formed as imbricates and associated minor duplexes within the shallow strata. The Pengguan fault has a steep dip at the shallow surface and a gentle dip at depth. Both the Beichuan-Yingxiu fault and the Pengguan fault were developed on the shallow detachment in the central segment of Longmen Shan. The third (No. ③) Pengguan fault is coincident with the co-seismic surface ruptures. It was a pre-existing fault and re-activated during the Wenchuan earthquake. Three-dimensional geometries show that the No. ③ fault is heterogeneous and it has controlled the slip of co-seismic ruptures. Based on the regional geology, the 3-D fault geometry and the surface ruptures, the frontal zone of the Central Longmen Shan has been divided into the Bailu segment and the Hanwang segment. Our studies suggest that the Pengguan fault has been active since the Cenozoic. The frontal zone of the Central Longmen Shan thrust belt has potential for future earthquakes.

SUMMARY This paper investigates the potential of double-layer space structures to be applied vertically as a new structural system in super-tall buildings. The investigation using case studies covers four stages: structural designs of 100-storey buildings in order to obtain internal force distributions and determine appropriate structural member sizes, analyses of the impacts of wind and seismic loads on the structures, sensitivity of structural weight ratios and lateral deflection constraints to changing structural geometry, and comparison of the lateral deflected shapes and structural weights per unit area with those of other current tall structural systems. The results show that changing the angles of diagonal members to make them span two storeys rather than one storey reduces structural weight and has little impact on lateral deflection. Compared with other current tall structures, vertical double-layer space structures are relatively efficient structurally. The study concludes that double-layer space structures can be applied vertically as a structural system of super-tall buildings. Copyright © 2012 John Wiley & Sons, Ltd.

Objective: Regenerative bioprostheses are being investigated for replacement of dysfunctional myocardium worldwide. The aim of this study was to develop a degradable magnesium structure to mechanically support the delicate biological grafts during the early remodeling phase. Methods: Sheets of magnesium alloys (LA33, LA63 and AX30) were manufactured into scaffolds by abrasive water jet cutting. Thereafter, their surface properties, corrosion kinetics, and breakage behaviors were investigated. Results: The magnesium alloy LA63 sheets proved superior to the other alloys in terms of load cycles (lc) until break of the specimens (LA63: >10 Mio lc; AX30: 676,044±220,016 lc; LA33: 423,558±210,063 lc; p Conclusion: The findings on alloy composition, coating, structural geometry and manufacturing parameters constitute a basis for clinically applicable magnesium scaffolds. The use of stabilized, regenerative myocardium prostheses could save the patients from severe morbidity and eventually death.

The Al Jabal al Akhdar and Saih Hatat culminations in the central Oman Mountains expose the complete mid-Permian to Late Cretaceous (Cenomanian) passive shelf and margin carbonate sequence beneath the allochtonous slope (Sumeini Group), basin (Hawasina complex), distal ocean-trench (Haybi complex) facies rocks, and the Semail ophiolite thrust sheets that were emplaced from NE to SW during the Late Cretaceous. Reconstruction of the pre-thrust sequences shows that time-equivalent rocks occur in successively stacked thrust sheets from shelf to slope to basin. The Al Jabal al Akhdar structure is a 60 km wavelength anticline plunging to the northwest beneath the Hawasina Window and with a fold axis that curves from WNW-ESE (Jabal Shams) to NNE-SSW (Jabal Nakhl). The structure shows little internal deformation except for minor intra-formational thrust duplexing within the Cretaceous shelf stratigraphy along the northern margin. The upper structural boundaries around the flanks of the shelf carbonate culminations have been re-activated as late stage normal faults. The Semail thrust formed a passive roof fault during late-stage culmination of al Al Jabal al Akhdar such that the ophiolite rests directly on Wasia Formation top-shelf with the entire Sumeini, Hawasina and Haybi thrust sheets displaced around the margins. NE-directed backthrusting and intense folding in the northern part of the Hawasina Window affects all allochtonous units and is related to a steep ramp in the Late Cretaceous shelf margin at depth. The Saih Hatat culmination is another 40 km half-wavelength anticline in the central Oman Mountains, but shows extreme deformation in the form of recumbent folds, sheath folds with NNE-trending axes and thrusting along the northern margin. High-pressure carpholite, blueschist and eclogite facies rocks are exposed at successively deeper structural levels, separated by high-strain normal sense shear zones. There is no evidence for a separate ‘North Muscat microplate’ or an intra-continental subduction zone, as previously proposed; all high-pressure units can be restored to show their pre-deformation palaeographic positions along the northern margin of the Arabian Plate. Both Al Jabal al Akhdar and Saih Hatat are Late Cretaceous culminations, folded after obduction of the Hawasina, Haybi and Semail ophiolite thrust sheets from northeast to southwest during the period Turonian to Campanian-Lower Maastrichtian. Maximum compressive stress along the central Oman Mountains was oriented NE-SW, parallel to the ophiolite emplacement direction, but a second compressive stress axis was oriented WNW-ESE, either concurrently or slightly later in time, resulting in a dome and basin structural geometry. The biaxial fracture pattern in the foreland, southwest of the Oman Mountains could be explained as a result of the WNW-directed emplacement of the Masirah ophiolite belt and Batain mélange during the Campanian-early Palaeocene. Both Al Jabal al Akhdar and Saih Hatat were positive topographic features at the end of the Cretaceous with Upper Maastrichtian and Palaeogene sediments onlapping both flanks. In Jabal Abiad, these Palaeogene sediments have been uplifted by at least 2 km since the Late Miocene-Early Oligocene associated with minor NNE-SSW compression. Tertiary shortening, folding and thrusting increases to the north in the Musandam peninsula where the first effects of the Arabian Plate-Eurasian Plate (Zagros belt) continent-continent collision are seen.

Funicular geometries, which follow the idealized shapes of hanging chains under a given loading, are recognized as materially efficient structural solutions because they exhibit no bending under design loading, usually self-weight. However, there are circumstances in which nonstructural conditions make a funicular geometry difficult or impossible. This paper presents a new design philosophy, based on graphic statics, that shows how bending moments in a nonfunicular two-dimensional curved geometry can be eliminated by adding forces through an external posttensioning system. An interactive parametric tool is introduced for finding the layout of a posttensioning tendon for any structural geometry. The effectiveness of this approach is shown with several new design proposals.

This chapter covers some basic concepts that must be considered in submerged breakwater design. A brief description is presented of the physical parameters that can be characterized as the most important factors influencing the wave transformation process, including incident wave height, incident wave period, incident wave length, breakwater crest height, water depth, submergence depth, crest width, and breakwater slopes. Other fundamental definitions of terms are also provided, such as refraction, reflection, wave overtopping, etc. The major aspects of wave behavior in the vicinity of a submerged structure that are crucial to the breakwater design process are outlined and discussed, with important equations presented. How the structural geometry of the submerged breakwater affects hydrodynamics is also described briefly in this introductory chapter.

The fire safety of existing structures is very important from the socio-economic point of view and has high social impact for civil, industrial and commercial buildings. The minimum fire resistance of structures is verified through some regulations, drafted to ensure safety for occupants and rescue teams as well as limited structural damage. Fire design rules are not always directly applicable to existing buildings, which need specific provisions to take account of uncertainties on the structural geometry, and the mechanical and thermal properties of the materials. This paper aims to provide guidance about the assessment of structural fire safety of existing buildings during a fire. A possible approach is obtained by integrating the general approach suggested by the Eurocodes for the structural assessment of existing buildings with more specific details concerning the structural fire safety check. The approach focuses on the criteria and the tests required to assess thermal properties and effectiveness of protective materials. The methodology is applied to assess an existing steel building protected with intumescent coating (IC), designed and built about 30 years ago. Applied to assess the existing IC, the procedure also provides data required to design a new protection system with advanced calculation methods according to a performance-based approach.

article is a report of the attempts which were made to model an industrial premix gas burner which was operating in one of the furnaces of the Catalytic Reforming Unit (CRU) of Abadan refinery. The main objective of the modeling was to investigate on the effect of the structural geometry of the burner on its mode of operation, i.e. complete combustion of the gas, maximum generation of heat and production of a proper flame configuration. For this goal, fundamental equations of the conservation of mass, momentum and energy for fuel-air mixture flowing in the burner were written and solved by using the Computational Fluid Dynamic (CFD) techniques and the results were analyzed. The main conclusion of the research was that various effects of the changes in the burner come to appear and an appropriate correction on the burner was recommended to the industry.

A series of diverse NH- and CH-acids are used for a one-pot synthesis of stable phosphorus ylides and 1,4-diionic organophosphorus compounds by trapping of the zwitterionic intermediate from the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates under solvent-free conditions. The structural geometry for one of the products was confirmed by single crystal X-ray diffraction analysis. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

The northwest terminus of the Himalayan range forms a syntaxis limited by two strike-slip faults, the Chaman Fault to the west, and the Karakorum Fault to the east. In between these faults, smaller-scale syntaxes are observed, as the Nanga Parbat and the Kashmir syntaxes. The fold axial traces of these syntaxes trend nearly north–south, revealing a component of east–west shortening in the geodynamic context of the north–south convergence between India and Asia. We constructed a sandbox with two edges oblique to the convergence to test the influence of the NW Himalayan syntaxis large-scale structural geometry on the construction of a wedge and on its evolution. We used sand and microbeads as standard analogues for brittle crustal layers approximately 30 km thick. We show that the obliquity of the edges can generate an east–west shortening in a north–south convergence. The amount of east–west shortening generated by the oblique edges of the box is up to 40% of the amount of the north–south convergence. This...

In the north-western Gawler Craton of South Australia, the Karari Shear Zone defines a boundary between late-Archean to earliest Paleoproterozoic rocks, which have remained largely undisturbed since the earliest Paleoproterozoic, and younger Paleoproterozoic rocks that have been reworked through multiple late Paleoproterozoic and Mesoproterozoic metamorphic and deformation events. The history of movement across the Karari Shear Zone has been investigated via new U–Pb and 40Ar/39Ar geochronology, in combination with pre-existing geochronological and metamorphic constraints, as well as the structural geometry revealed by a recently acquired reflection seismic transect. The available data suggest a complex history of shear-zone movement in at least four stages, with contrasting sense of motion at different times. The first period of movement across the Karari Shear Zone is inferred to have been a period of extension at ca 1750–1720 Ma. This was likely closely followed by reactivation during the Kimban Orogen...

Vehicle emissions inside an urban environment are investigated using a wind-tunnel under neutral atmospheric conditions. The urban environment was formed as street canyon model. The diffusion flow field in the boundary layer inside the street canyon was examined at different locations of varying geometry of the street and wind directions in the downwind distance of the leeward side of the street canyon model. The results show that the vertical velocity increases as the aspect ratio increases and with wind direction increases from θ = 90°. The pollutant concentration increases as the aspect ratio decreases. The pollutant concentration decreases as the wind direction increases from θ = 90°. The pollutant concentration distributions indicate that the variability of the structure, geometry and wind direction inside the street canyon are important parameters for estimating air quality in the urban street canyon.

Evolution of materials, following the design requirements of special structures, has shifted interest towards development of composite members able to meet strength requirements “tailored” to specific applications. These members can provide appropriate, more cost effective structures, however absence of generic design guidelines raise constraints towards derivation of optimized structures. Reliability-based assessment can overcome this limitation by ensuring that acceptable levels of target reliability are achieved throughout their service life. This paper presents a methodology for reliability assessment of composite members based on appropriate limit state functions derived according to fundamental failure criteria, Tsai-Hill and Tsai-Wu, applicable to composite materials. The methodology that is proposed employs a Stochastic Response Surface Method (SRSM) which combines in discrete steps FEA modelling, numerical simulations and analytical probabilistic assessment techniques, allowing use of commercial and custom developed specialized numerical tools. Application of the proposed methodology on a complex composite structural geometry will illustrate its efficiency and evaluate the reliability performance of the limit states derived and examined.

In heritage preservation, there is crucial need to identify the potential seismic risk in existing historic buildings for hazard mitigation, disaster preparedness and prior knowledge of potential hazards. Seismic risk evaluation is based on safety assessment which requires qualitative and quantitative data. This data is necessary before making any intervention decision. The qualitative data is visual inspection of decays, structural damages and deteriorations; and the quantitative data requires laboratory tests, structural analysis etc. Obtaining the quantitative data is detailed method, which necessitates specialists and takes more time and money. The fact that there are so many historic buildings and a few specialists on this field it is very important to make condition survey based on visual inspection as a first step of safety assessment procedure. According to these results necessity of detailed inspection and intervention and restoration works and the budged can be prioritized. This paper aims to present condition survey criteria generally and to focus on visual inspection as a first step of safety assessment. The data given in this paper is a part of author’s PhD study in which visual inspection method for assessing the risk level of masonry monumental historic structures is developed. The paper deals with Murat Pasha Mosque as a case study.

SUMMARY The architectural expressions for many modern buildings require creative and unconventional structural solutions. Columns must be taller, beams must span further, the structure must be more slender, elements must be curved, structural framing must be sloped and connections must deviate from conventional orthogonal fit-up. Although the technology exists to analyze and design responsive structural systems, prescriptive code requirements oftentimes hinder the implementation of those technologies. Although not a ‘tall building’ by traditional definition, the Tom Bradley International Terminal (TBIT) Modernization Program at Los Angeles International Airport (LAX) provides an appropriate case study in the implementation of unconventional structural geometry subject to code requirements that prescribe contrasting conventional geometry, which is a familiar challenge for many tall buildings. The architectural expression for the LAX TBIT Modernization Program required the use of long-span steel Special Moment Frames with non-orthogonal moment connections between the beams and columns. The beams were sloped, some were sloped and curved and some of the columns were sloped. The reduced beam section (RBS) moment connection was selected for the project. ANSI/AISC 358, Prequalified Connections for Special and Intermediate Steel Moment Frames for Seismic Applications, provides prequalification limits for using an RBS connection. Those limits do not address non-orthogonal moment connections. ANSI/AISC 358 implicitly limits connections to orthogonal geometry; hence, non-orthogonal moment connections are not prequalified for use in seismic applications. This paper describes the structure and the cyclic testing program that was implemented to qualify the proposed non-orthogonal RBS connections in accordance with ANSI/AISC 341, Seismic Provisions for Structural Steel Buildings, Appendix S for use on the LAX TBIT Modernization Project. Copyright © 2011 John Wiley & Sons, Ltd.

Hierarchically designed tubular scaffolds with bi-layer and multi-layer structures are expected to mimic native vessels in its structural geometry. A new approach for the fabrication of hierarchically designed tubular scaffold with suitable morphology was introduced through electrospinning technique. Among these scaffolds, bi-layer scaffold had a single inner and outer layer whereas multilayer scaffold had more number of inner layers. The inner layer/layers of the scaffolds were made up of aligned poly (lactic acid) (PLA) fibers for EC adhesion where as outer layers were composed of random fibers of poly (caprolactone) (PCL) and PLA providing larger pores for SMC penetration. The fabricated scaffolds were characterized by FTIR spectroscopy and Differential Thermal Analysis (DTA) and examined by evaluating cellular interactions. Human Umbilical Vein Endothelial Cells (HUVECs) seeded on aligned PLA fibers showed enhanced cellular orientation and cytoskeletal organization. In addition, the PCL-PLA composite random fibers supported SMC adhesion and proliferation sufficiently. The functionality of the endothelial cells grown on the PLA-aligned scaffold was also found to be satisfactory. Lining the constructs with a luminal monolayer of well-organized ECs along with homogenously distributed SMCs surrounding them might result in vascular conduits suitable for in vivo applications. Since this hierarchically designed tubular scaffold closely mimics the morphology of native vessel, this could be a better candidate for vascular tissue engineering.

Under severe sea wave conditions, the mooring tethers of submerged floating tunnel (SFT) might go slack. It may cause the structure failure during the service lifetime of SFT. The paper investigated SFT dynamics when going through tether slacking and the related snap force under wave conditions. Besides the nonlinearity of fluid drag and of structural geometry for a relative large structure displacement, the problem is characterized by the nonlinearity due to the discontinuity in axial stiffness of the tethers. To include these nonlinearities, the method of Lagrange energy is used to build the governing equations of SFT motion, and a bilinear oscillator is introduced to simulate the mooring tether operating in an alternating slack-taut state. The sensitivities of the occurrence of tether slacking to wave height and wave period are investigated. Results show that at a large wave height SFT tether will go slack and snap force occurs. SFT responses are categorized into three types of state according to the dynamic response characteristics of tether tension. Effects of two fundamental structure parameters, buoyancy-weight ratio (BWR) and inclined mooring angle (IMA), on the dynamic responses of SFT are analyzed. A slack-taut map of SFT tethers is built. It intuitively describes the occurrences of slack and snap force with different combinations of the two parameters. An analytical approach for slack prediction by deriving the slack criterion is provided to reveal the mechanism of the presented slack-taut map. By present research, the authors tried to make their effort to provide an alternative philosophy for SFT structural design on concerning preventing the occurrence of tether slacking and snap force. (C) 2011 Elsevier Ltd. All rights reserved.

PurposeThe purpose of this paper is to demonstrate the preliminary work on using laser cladding technology for the restoration of structural integrity.Design/methodology/approachThe primary methodology used in this research is to develop a laser cladding‐based metal deposition technique to articulate restoration of structural geometry affected by corrosion damages. Following from this method, it is planned to undertake further work to use the laser cladding process to restore geometry and the associated static/fatigue strength.FindingsThis work has found that it is possible to use laser cladding as a repair technology to improve structural integrity in aluminium alloy aircraft structures in terms of corrosion reduction and geometrical restoration. Initial results have indicated a reduction of static and fatigue resistance with respect to substrate. But more recent works (yet to be published) have revealed improved fatigue strength as measured in comparison to the substrate structural properties.Originality/valueThe research is based on an acceptable materials processing technique.

The strong demand for increasing productivity and workpiece quality in milling process makes the machine-tool system operate close to the limit of its dynamic stability. Milling cutters with variable pitch angles can be very effective in improving stability against chatter for certain speed ranges, which will be predicted by the model presented here. The present paper deals with the design of structural geometry of variable pitch end mills in detail. Based on the analysis of tooth engagement factor, which is expressed and extended in the paper, an approach is proposed to design variable pitch end mill with high milling stability. The certain speed ranges with high milling stability are given.

Experimental modeling is used to study the geometry and evolution of structures and related secondary faults along releasing bends and offsets and restraining bends on strike-slip faults. The controls of the relative positions of adjacent strike-slip faults on the geometry of the structures and the difference in geometries between bends and offsets are investigated. A new method of laser scanning is used to map the geometry and evolution of the structures and related faults. The models show that oblique releasing bends connecting approaching faults result in spindle-shaped basins, whereas transverse bends result in more S-shaped or rhomboidal basins. Offsets result in the distribution of strain over a wider area and a larger number of faults compared with preexisting bends, which result in fewer well-defined basin-bounding faults. Secondary faults include R, R, and Y Riedel shears near the main strike-slip faults and oblique normal faults in the center of the basin. Fault patterns exhibit en echelon geometries with a progressive step down into the deepest parts of the basin. Symmetric, asymmetric, and double basins may form in any of the structural settings, depending on the slip distribution among faults on the basin margins. For restraining bends, oblique (45) bends connecting approaching faults result in spindle-shaped uplifts, whereas transverse or oblique (135) bends connecting overlapping faults result in more rhomboidal or rectangular uplifts. The fold trends are at increasingly higher angles with the strike faults for transverse and oblique (135) bends. Secondary faults include en echelon reverse faults, which typically form along the steep limbs of asymmetric uplifts, normal faults, which are transverse or oblique to the axis of the structure, and R, R, and Y Riedel shears near the main strike-slip faults. The aspect ratios of the basins and uplifts increase with increasing displacement on the strike-slip faults. The results of these models can be used to interpret the structural and fault geometries in surface and subsurface structures formed along strike-slip faults.

The strong demand for increasing productivity and workpiece quality in milling process makes the machine–tool system operate close to the limit of its dynamic stability. Besides predicting accurately chatter stability, it is required that some optimizations should be conducted, e.g., cutter structure, for improving the dynamic stability limits. Milling cutters with variable pitch angles can be very effective in improving stability against chatter for certain speed ranges, which will be predicted by the model presented here. The present paper deals with the design of structural geometry of variable pitch end mills in detail. Based on the analysis of tooth engagement factor, which is expressed and extended in the paper, an approach is proposed to design variable pitch end mill with high milling stability. The certain speed ranges with high milling stability are given. An example of the design of variable pitch end mills is illustrated to demonstrate the validity of this method.

The structural geometry, electronic structure, photophysical properties, and the fluxional behavior of a series of A-frame diplatinum alkynyl complexes, [Pt(2)(μ-dppm)(2)(μ-C≡CR)(C≡CR)(2)](+) [R = (t)Bu (1), C(6)H(5) (2), C(6)H(4)Ph-p (3), C(6)H(4)Et-p (4), C(6)H(4)OMe-p (5); dppm = bis(diphenylphosphino)methane], have been studied by density functional theory (DFT) and time-dependent TD-DFT associated with conductor-like polarizable continuum model (CPCM) calculations. The results show that the Pt···Pt distance strongly depends on the binding mode of the alkynyl ligands. A significantly shorter Pt···Pt distance is found in the symmetrical form, in which the bridging alkynyl ligand is σ-bound to the two metal centers, than in the unsymmetrical form where the alkynyl ligand is σ-bound to one metal and π-bound to another. For the two structural forms in 1-5, both the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy levels show a dependence on the nature of the substituents attached to the alkynyl ligand. The energies of the HOMO and LUMO are found to increase and decrease, respectively, from R = (t)Bu to R = Ph and to R = C(6)H(4)Ph-p, because of the increase of the π- conjugation of the alkynyl ligand. On the basis of the TDDFT/CPCM calculations, the low-energy absorption band consists of two types of transitions, which are ligand-to-ligand charge-transfer (LLCT) [π(alkynyl) → σ*(dppm)]/metal-centered MC [dσ*(Pt(2)) → pσ(Pt(2))] transitions as well as interligand π → π* transition from the terminal alkynyl ligands to the bridging alkynyl ligand mixed with metal-metal-to-ligand charge transfer MMLCT [dσ*(Pt(2)) → π*(bridging alkynyl)] transition. The latter transition is lower in energy than the former. The calculation also indicates that the emission for the complexes originates from the triplet interligand π(terminal alkynyls) → π*(bridging alkynyl)/MMLCT [dσ*(Pt(2)) → π*(bridging alkynyl)] excited state. In terms of the fluxional behavior, calculations have been performed to study the details of the mechanisms for the three fluxional processes, which are the σ,π-alkynyl exchange, the ring-flipping, and the bridging-to-terminal alkynyl exchange processes.

This work compares dual gate and single gate a-InGaZnO thin film transistor devices under single gate operations. In both devices, an abnormal drain current increase in the dual gate structures was observed. The results of structural geometry experiments, Technology Computer-Aided Design, and theoretical calculations matching the experimental results provide evidence for a larger voltage potential distribution located near the top gate even when the top gate is floating. Since an additional voltage is formed near the top gate, a better gate control capability will lead to more inverted carriers. Therefore, these dual gate structures have a larger drain current than does the single gate. Finally, both positive bias stress and negative bias illumination stress in both structures are discussed. The results of positive bias stress have shown good quality of the gate insulator layer and negative bias illumination stress was discussed to confirm the coupled voltage.This work compares dual gate and single gate a-InGaZnO thin film transistor devices under single gate operations. In both devices, an abnormal drain current increase in the dual gate structures was observed. The results of structural geometry experiments, Technology Computer-Aided Design, and theoretical calculations matching the experimental results provide evidence for a larger voltage potential distribution located near the top gate even when the top gate is floating. Since an additional voltage is formed near the top gate, a better gate control capability will lead to more inverted carriers. Therefore, these dual gate structures have a larger drain current than does the single gate. Finally, both positive bias stress and negative bias illumination stress in both structures are discussed. The results of positive bias stress have shown good quality of the gate insulator layer and negative bias illumination stress was discussed to confirm the coupled voltage.

Terra Nova, 22, 390–395, 2010 Abstract We present the results of coupled analogue and numerical models that provide new insights into the relationships between volcanoes and thrusts. The effects of both upper-crustal magma chambers and the load of volcanoes on the geometry of thrust systems were investigated. Analogue modelling points to a strong influence exerted by a magma chamber on thrust geometry, which, as suggested by the numerical models used to rationalize these results, is related to the stress redistribution around the weak heterogeneity. The low-viscosity body below a volcanic edifice localizes compressional deformation and causes a curvature of the thrusts towards the magma chamber, opposite to the direction of tectonic transport. In these conditions, the volcanic load has a negligible effect on the structural geometry. These results are in contrast with those of previous studies, where intrusions or the load of major volcanoes generated a curvature of the thrusts away from volcanic edifices in the direction of tectonic transport.

As a typical half-graben in the deep water area of the southern Qiongdongnan basin,the Beijiao sag with the "leg bend-like" deformation of its sequence stratigraphy is consistent with the model of extensional fault-bend fold.Using the theory of extensional fault bend fold and balanced cross-section,we reconstructed the evolutionary process of the Beijiao sag and Beijiao low-uplift in terms of extentional tectonics.After analysing and measuring the structural deformation of the sag,the geometric character and kinematic process of the fault bend fold are established.It is estimated that the sag totally extended 12 km with an average extension rate of 0.44 km/Ma during the period from 50 Ma to 23 Ma,and the sea level of this area rose about 200 m by the end of Eocene.

Bone shape, mass, structural geometry, and material properties determine bone strength. This study describes novel software that uses peripheral quantitative computed tomography (pQCT) images to quantify cortical bone shape and investigates whether the combination of shape-sensitive and manufacturer's software enhances the characterization of tibiae from contrasting populations. Existing tibial pQCT scans (4% and 50% sites) from Gambian (n=38) and British (n=38) women were used. Bone mass, cross-sectional area (CSA), and geometry were determined using manufacturer's software; cross-sectional shape was quantified using shape-sensitive software. At 4% site, Gambian women had lower total bone mineral content (BMC: −15.4%), CSA (−13.4%), and trabecular bone mineral density (BMD: −19%), but higher cortical subcortical BMD (6.1%). At 50% site, Gambian women had lower cortical BMC (−7.6%), cortical CSA (−12.6%), and mean cortical thickness (−15.0%), but higher cortical BMD (4.9%) and endosteal circumference (8.0%). Shape-sensitive software supported the finding that Gambian women had larger tibial endosteal circumference (9.8%), thinner mean cortical thickness (−26.5%) but smaller periosteal circumference (−5.6%). Shape-sensitive software revealed that Gambian women had tibiae with shorter maximum width (−7.6%) and thinner cortices (−22% to −41.2%) and more closely resembled a circle or ellipse. Significant differences remained after adjusting for age, height, and weight. In conclusion, shape-sensitive software enhanced the characterization of tibiae in 2 contrasting groups of women.

A mathematical analysis of the mechanical governing equations applying to the torsional behaviour of multi-ply yarns under tension has been carried out. This analysis clearly shows that there are two components, a geometric component that determines the slope or gradient of the torque due to tension and a component that determines the yarn torque at zero applied tension (intrinsic torque) that depends on the fibre number, fibre moduli and diameter as well as the strand structural geometry. The effect of the ratio of the ply twist to the spinning twist on the two components of yarn torque has been numerically analysed for two-, three- and four-ply yarns prepared from singles 31 yarns spun with different spinning twists and for two different fibre diameters. Other comparisons are made for two-ply yarns prepared from 40 and 80 tex singles yarn. The model allows the effects of the various yarn and fibre parameters to be assessed and compared with experimental data. Experimental torque data for a range of two-...

With the recent developments in structural analysis and material technologies, engineers can now use framing systems and construction materials in a more efficient manner. This results in a reduction in safety margins and the reserve capacity of structures to accommodate abnormal or accidental loading conditions. The consideration of progressive failure or collapse in the design process has also become increasingly important. In view of this, there is a need to modify traditional teaching methods in the education of the new generation of structural engineers with the view to build up their conceptualisation of local and global structural behaviour to gain a clear understanding of the progressive failure or collapse of structural systems. In achieving this goal, we propose to educate structural engineering students using ‘virtual’ experiments in a self-learning environment that allows them to observe changes in structural behaviour instantly as one changes to structural geometry, support conditions, member...

This study examines the structural characteristics of the northern Gulf of California by processing and interpreting ca. 415 km of two-dimensional multi-channel seismic reflection lines (data property of Petroleos Mexicanos PEMEX) collected in the vicinity of the border between the Wagner and Consag basins. The two basins appear to be a link between the Delfin Superior Basin to the south, and the Cerro Prieto Basin to the north in the Mexicali-Imperial Valley along the Pacific–North America plate boundary. The seismic data are consistent with existing knowledge of four main structures (master faults) in the region, i.e., the Percebo, Santa Maria, Consag Sur, and Wagner Sur faults. The Wagner and Consag basins are delimited to the east by the Wagner Sur Fault, and to the west by the Consag Sur Fault. The Percebo Fault borders the western margin of the modern Wagner Basin depocenter, and is oriented N10°W, dipping (on average) ∼40° to the northeast. The trace of the Santa Maria Fault located in the Wagner Basin strikes N19°W, dipping ∼40° to the west. The Consag Sur Fault is oriented N14°W, and dips ∼42° to the east over a distance of 21 km. To the east of the study area, the Wagner Sur Fault almost parallels the Consag Sur Fault over a distance of ∼86 km, and is oriented N10°W with an average dip of 59° to the east. Moreover, the data provide new evidence that the Wagner Fault is discontinuous between the two basins, and that its structure is more complex than previously reported. A structural high separates the northern Consag Basin from the southern Wagner Basin, comprising several secondary faults oriented NE oblique to the main faults of N–S direction. These could represent a zone of accommodation, or transfer zone, where extension could be transferred from the Wagner to the Consag Basin, or vice versa. This area shows no acoustic basement and/or intrusive body, which is consistent with existing gravimetric and magnetic data for the region.

Bones are composed of hierarchical bio-composite materials characterized by complex multiscale structural geometry and behaviour. Currently, there is great interest within the biomedical community in developing accurate non-invasive techniques for analysing bone micro-structure. We propose a new approach of multiscale finite element analysis of bone micro-structure which can provide physicians with a ‘digital magnifying glass’ providing a continuous bi-directional transition between macro- and micro-scales. In the macro-scale, the material appears to be smoother and more homogeneous. The zooming-in process reveals additional details and the heterogeneity of the material. In this paper we deal with the 2D geometric aspects, demonstrating the feasibility of the proposed method, using a multiscale domain-based geometric model.

Based on the microstructure of three-dimensional (3D) four-directional rectangular braided composites, a new parameterized 3D finite element model (FEM) is established. This model precisely simulates the spatial configuration of the braiding yarns and considers the cross-section deformation as well as the surface contact due to the mutual squeezing in the braiding process. Moreover, it is oriented in the same reference frame as the composites, which coincides with the actual configuration of 3D braided composites and facilitates the analysis of mechanical properties. In addition, the model investigates the relationships among the structural parameters, particularly the braiding angle and the interior braiding angle, which were not taken into account in the previous models. Based on the parameterized FEM, the structural geometry of the composites is analyzed and some conclusions are drawn herein. Good agreement has been obtained between the calculated and measured values of the geometric characteristics of braided composite samples.

Thrust duplexes account for large fractions of the total shortening in most fold-thrust belts (FTBs). They also provide an efficient mechanism for transferring slip upward from the basal decollement and for transporting roof thrust sheets over long distances. The Lesser Himalayan duplex (LHD) plays a prominent role in the overall evolution of the Himalayan FTB and has been described from Garhwal-Kumaon to Bhutan. In Sikkim the LHD shows unique structural geometry and has been responsible for transporting crystalline thrust sheets (MCT 1 and MCT 2) farther southward than other parts of the Himalaya. Such lateral variations in LHD geometry imply variations in the kinematic history of the Lesser Himalaya and variations in shortening and shortening history along the length of the Himalayan arc, and these are reflected in observable large scale structural patterns.

Multi-scale edge detection was applied to potential field data over the Gawler Province in the central part of South Australia. Also known as worming, the multi-scale edge analysis technique can aid identification of structural controls and depth extents of anomalies. A geological interpretation of the multi-scale edge detection results was then undertaken; integrating drill-hole information, ground mapping and tectonic understanding with geophysical modelling to gain a better comprehension of the dominant structures present. The multi-scale edge detection process provides potential solutions for the lack of outcrop, particularly that which is representative of three-dimensional architecture. The latter is particularly important in understanding how terrains are juxtaposed or dissected tectonically which, in turn, influences the style of any mineral system that may be present. Moreover, correct identification of structural geometry and cross-cutting relationships allows a more confident assessment of fault kinematics and potential dilatancy. In particular, the degree of uranium mineralisation in iron-oxide-copper-gold systems in the Gawler Province may be dependent on the interconnectivity of fault plumbing in three dimensions to nearby uraniferous Mesoproterozoic granitoids.

Site measurements have shown that slab loads re-distribute, between the slabs during the concrete curing, while the external loadings and structural geometry remain the same. Some have assumed that this is caused by concrete shrinkage and creep, but there have been no studies on how these factors exactly influence the load distributions and to what degree these influences exist. This paper analyzes the influences of concrete shrinkage, creep, and temperature on the load re-distributions among slabs. Although these factors may all lead to load re-distribution, the results show that the influence of concrete shrinkage can be neglected. Simulations indicate that shrinkage only reduces slab loads by a maximum of 1.1%. Creep, however, may reduce the maximum slab load by from 3% to 16% for common construction schemes. More importantly, temperature variations between day and night can cause load fluctuation as large as 31.6%. This analysis can, therefore, assist site engineers to more accurately estimate slab loads for construction planning.

Shell repair assumed to result from failed predation is documented in 66 specimens of Ordovician-Carboniferous bellerophontiform tergomyan and gastropod molluscs to examine the relationship between the distribution and appearance of injuries, shell morphology and the internal anatomy of the molluscs, as well as the attack strategies of the presumed predators. Furthermore, the distribution of repaired injuries from failed attacks along the apertural margin as a reflection of the nature of the margin and emarginations is investigated. Bellerophontiform molluscs are ideal for this study because of their distinctive isostrophic morphology and the possibility to directly compare broad and narrow conchs with either deep or shallow medial emarginations. The results show that taxa with a deep medial emargination in the form of a slit have significantly more medial injuries than lateral ones. Near-equal frequencies of lateral and medial injuries in specimens with a shallow emargination (slit or sinus) suggest random distribution. Shell form (narrow or broad) does not exert overall control on the distribution of injuries except, perhaps, in some broad explanate shells with an insignificant medial emargination. While this suggests that it is the type of medial emargination that governs distribution of injuries in these forms, it is not clear if this is a result of passive selection due to structural geometry or preferential targeting by predators (i.e. site-specific mode of attack). Predation strategies on bellerophontiform molluscs thus seem to be dependent on the morphological features of the shells rather than their interpretation as tergomyan or gastropod.

Understanding and interpreting the timing, location, orientation, and intensity of natural fractures within a geologic structure are commonly important to both exploration and production planning activities. Here we explore the application of finite-element-based geomechanical models to fracture prediction. Our approach is based on the idea that natural fractures can be interpreted or inferred from the geomechanical-model-derived permanent strains. For this analysis, we model an extensional fault-tip monocline developed in a mechanically stratified limestone and shale sequence because field data exist that can be directly compared with model results. The approach and our conclusions, however, are independent of the specific structural geometry. The presence or absence of interlayer slip is shown to strongly control the distribution and evolution of strain, and this control has important implications for interpreting fractures from geomechanical models.

Non-plane joints, such as T-joints, L-joints and  shaped joint can bring enormous potential benefits from the reduction of the fastener and the part count, which lead to the dramatic decrease of assemble cost and primary structural weight in composite structures. To understand the mechanistic character of the  joint, a 3-D finite element analysis model is established by means of software ABAQUS. The stresses on ply level and the predictions on the damage onset of 3-D woven composite π joint under tensile load are obtained. Numerical results agree well with empirical data. The effects of structural geometry parameters, such as support length, support thickness and radius of the corner, are also discussed. Results illustrated that increasing the thickness of L preform or filler radius can improve the strength of woven composite π joint effectively.