Bottom Element Research Articles

Performance of a buried pipeline along the dip of a slope experiencing accidental sliding

Contrary to highways, major pipelines often have to be installed crossing hills or mountain ridges, following the dip of the slope. Slope movements that may be triggered by an earthquake, heavy rainfall, an excavation at its toe, or long-term creep, constitute major hazards that must be considered in design. This paper studies numerically the interaction of a steel pipeline with a rotational slide originating at the crest of a slope and evolving in the direction of the pipeline axis. Different pipeline-slide mechanisms are examined: a reference slide taking place in a rather shallow slope in which the sliding surface crosses the pipe over its straight portion, a deeper scenario where the toe of the slide interacts with the bottom elbow element of the pipeline, and two much steeper scenarios. A two-step finite-element methodology is developed and validated against several published experiments. The analysis simulates realistically the soil sliding process and all possible modes of pipeline failure. The pipeline performance is discussed for a range of internal pressure scenarios: from empty to full operating at maximum allowable pressure (pmax). It is found that the relative position of the slip-line to the pipeline axis (at their intersection) determines the amount of bending induced in the pipeline and eventually the vulnerability of the installation. For empty pipes the prevailing failure mode is inward buckling, whereas pressurised pipelines rupture at larger displacements due to excessive accumulation of tensile strains. When the slip-line of the sliding mass crosses the toe of the slope, excessive bending is experienced at the lower bend of the installation, which is translated into a compressive force, invariably speeding up pipeline failure. Here the failure mode is always buckling: inward for non-pressurised pipes and outward for non-zero internal pressures.

Experimental investigations on seismic behavior and design of bottom vertical boundary elements in multi‐story steel plate shear walls

SummaryThis research investigates the seismic behavior and design method for the bottom‐level boundary columns, also called the vertical boundary elements (VBEs), in multi‐story steel plate shear walls (SPSWs). This paper firstly introduces the proposed design method for the bottom‐level VBE for the case when a frame swaying action causes the VBE to bend in single curvature, as is often seen in mid‐ and high‐rise buildings. Two 12‐story (12F) prototype SPSWs were designed using the proposed design method. Two 40%‐scale substructural test specimens representing the first 2.5 stories of the 12F SPSW prototype designs were cyclically tested with the Multi‐Axial Testing System at the Taiwan National Center for Research on Earthquake Engineering in 2013. The test results confirm the effectiveness of the proposed design method in predicting the yielding of the top end of the bottom VBE. In addition, test results show that the lateral torsional buckling of the bottom VBE could occur after the VBE top end yields, indicating that premature top‐end yielding should be prohibited for the bottom VBE before the SPSW develops uniform yielding mechanism under the lateral forces.

Multidisciplinary teams for the proper management of patients with genitourinary tumors: When topics set scientific societies' agenda.

The multidisciplinary management of oncologic patients is identified as the bottom line element of quality in tumor care. In 2015, 7 Italian scientific societies representing the specialists involved in the diagnosis and treatment of genitourinary tumors joined efforts in the Italian uro-oncologic multidisciplinary teams (MDTs) project. The aims were to promote the reorganization of genitourinary cancer care, switching to a multidisciplinary approach, reach a consensus on the core elements for the setup of MDTs in genitourinary oncology, and support health policy makers and managers in remodeling of the assistance and care of uro-oncologic patients on a national level. The first activity was the setup of 5 working groups, given the task of exploring selected topics: general principles, organization of MDTs, minimal requirements, economic evaluation, and relations with authorities. The groups participated in the writing of a document that was approved by the scientific societies and published on their web sites. Moreover, a few items summarizing the extensive document were approved in the first MDT Consensus Conference held in Milan in December 2015. The experience of this initial phase led to the opening of the team to other professionals and societies, in line with a correct management of patients with genitourinary tumors, which need a multidisciplinary as well as a multiprofessional approach with emerging techniques and procedures, and with a new project work package on genitourinary paths of care and indicators.

Boolean center of lattice ordered EQ-algebras with bottom element

In this paper, some new properties of $EQ$-algebras are investigated. We introduce and study the notion of Boolean center of lattice ordered $EQ$-algebras with bottom element. We show that in a good $ell EQ$-algebra $E$ with bottom element the complement of an element is unique. Furthermore, Boolean elements of a good bounded lattice $EQ$-algebra are characterized. Finally, we obtain conditions under which Boolean center of an $EQ$-algebra $E$ is the subalgebra of $E$.

ANALISIS BASE SHEAR STRUKTUR YANG MENGALAMI KERUSAKAN DENGAN CARA THA, CQC DAN SRSS AKIBAT BEBAN GEMPA

This study aims to analysis of base shear structure from effects of earth quakes. The methods were used to analysis with damage scenarios as follows: THA, CQC, and SRSS. The damage scenarios simulation was obtained by applying reduced stiffness on a bottom column element of frame. The reduced stiffness of column elements with damage scenarios as follows: 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, and 40%. CAL-91 was used for analysis and for obtaining base shear and frequency of structure. More big damage scenarios to apply at element bottom column of frame that reducing value of frequency and base shear of structure. The method THA only stable until damage scenarios 25%, while method CQC and SRSS stable permanent up to damage scenarios 40%.Key words: base shear, damage scenarios, THA, CQC, SRSS

A high-efficiency grating coupler between single-mode fiber and silicon-on-insulator waveguide**Project supported by the National Key Research and Development Program of China (No. 2016YFB0402404), the High-Tech Research and Development Program of China (Nos. 2013AA031401, 2015AA016902, 2015AA016904), and the National Natural Foundation of China (Nos. 61674136, 61435002, 61176053, 61274069)

We present the design of a diffractive grating structure and get the optimal parameters which can achieve more than 75% coupling efficiency (CE) between single-mode fiber and silicon-on-insulator (SOI) waveguide through 2D finite-different time-domain (FDTD) simulation. The proposed architecture has a uniform structure with no bottom reflection element or silicon overlay. The structure, including grating couplers, adiabatic tapers and interconnection waveguides can be fabricated on the SOI waveguide with only a single electron-beam lithography (ICP) step, which is CMOS-compatible. A relatively high coupling efficiency of 47.2% was obtained at a wavelength of 1562 nm.

USE OF MACROINVERTEBRATES FOR ASSESSMENT OF RESTORATION WORKS INFLUENCE ON THE HABITAT IN FLOODPLAIN LAKES

The paper presents a study concerning the influence of the hydraulic and hydrological connectivity among the oxbow lakes and the restoration of riparian-zones have on aging. Interconnectivity oxbow lakes emerge after complex regulating works for the protection of the shores and bottom of the lakes. Research has analyzed the influence of the hydraulic connectivity of three lakes located in northern Poland on the structure of associated bottom invertebrates elements that monitor the conditions in habitats. The structure and functioning of ecosystems in wetlands, including in oxbow lakes, are direct or indirect in connection to fluctuations in water levels during floods or flow pulsations. Hydrological processes cause changes in the chemical composition of the water in oxbow lakes and sediment dispersion due to the exchange between water and sediments. In the lentic habitats (disconnected from the main river), the retention time is longer than in the semi- and lotic oxbow lakes whereas the productivity of the ecosystem is only internal and limited. The use of macrozoobenthos as bioindicators in re-connected oxbow lakes in small river valleys indicates that, on the long-term period (5 years), it does not have as a result the improvement of the environmental conditions of those habitats. This is shown by the monitoring indicators. The main reason seems to be the loss of the full connectivity between the oxbow lakes and the main river channel within 3 to 4 years, having as a result only systems of semilotic oxbow lakes and rivers. This hampers the free exchange of waters between ecosystems, the washing out of nutrients accumulated in sediments, the removal of bottom sediments, as well as the migration of hydrobionts. Therefore, the improvement of the ecological condition of the oxbow lake habitats and the permanence of those changes depend on the possibility of keeping the full hydrological connectivity to the river.

TYPES OF STEEL AND CONCRETE COMPOSITE CABLE SPACE FRAMES

Purpose. Modern terms of the construction generate the need to find new structures, including roof systems that would meet modern requirements. An important aspect in finding constructive solutions for new structures is the use of reliable and advanced materials. Considering this, the decision to develop the new space structures to a wide implementation in practice of domestic and foreign construction are relevant and perspective direction of building structures development. Methodology. Given the results of previously conducted theoretical research of existing types of space roof structures find promising areas of improvement or creation of new structures that should be devoid of weaknesses and imperfections of analogs and they should have an economic effect through rational use of materials. Findings. Types of steel and concrete composite cable space frames and structural features of its elements are developed and considered. The steel and concrete composite cable space frame is a completely new kind of space structure system that has the original structural concept and it was designed to cover large-span industrial and public buildings. The basic elements of that structure system are modular element of the bottom chord and space steel and concrete composite module that consists of tubular rods and reinforced concrete slab. All modular elements are made in the factory. With bottom chord modular elements and space steel and concrete composite modules can be assembled three types of longitudinal elements. It is the beam element, arched element and hanging element. Also with the modules can be assembled various structure system and their combinations. Number of space steel and concrete composite modules and bottom chord modular elements, which is needed to collect steel and concrete composite cable space frames, is determined by calculation and optimal designing. Recommended dimensions of the modular elements of the steel and concrete composite cable space frames are presented. Originality. The new efficient construction roofs that appointment for covering large-span buildings were developed by the author. Practical value. Developed steel and concrete composite grid-gable roofs are designed for industrial and civil construction. Applications of developed designs for the construction of large-span covering objects provides a significant economic benefit through the efficient use of materials.

Cyclic hysteresis of AZ31B extrusion under load‐control tests using embedded sensor technology

AbstractThe fatigue behaviour of AZ31B extrusion magnesium alloy under load‐control cyclic test conditions is estimated using a combination of simulation and experimental results. The strain measurement of this asymmetric material is found experimentally using a Fibre Bragg Grating (FBG) sensor during rotating bending tests. Then, to analyse applied stresses in the sample – particularly in the plastic deformation range – the Variable Material Property (VMP) method is employed. Using this simulation method, the hysteresis loops of two critical top and bottom elements of the sample's cross section under different bending moments are obtained. Finally, the strain of the sample during rotating bending, as measured by the embedded FBG sensor, is related to the stresses obtained from the modeling using a mapping function. The hystereses obtained from this combination of the modeling and experimental results are compared with the results of a companion strain‐control pull–push test in which the input strain history was that of measured by the FBG sensor. Observations verify that the stresses of the combined VMP‐FBG hysteresis loops have good compatibility with the stress responses obtained through the experiment. The hybrid model introduced in this work can be employed to capture cyclic hysteresis, and hence estimate the fatigue life, under load‐controlled rotating bending tests.

LATTICE-ORDERED ABELIAN GROUPS AND PERFECT MV-ALGEBRAS: A TOPOS-THEORETIC PERSPECTIVE

AbstractWe establish, generalizing Di Nola and Lettieri’s categorical equivalence, a Morita-equivalence between the theory of lattice-ordered abelian groups and that of perfect MV-algebras. Further, after observing that the two theories are not bi-interpretable in the classical sense, we identify, by considering appropriate topos-theoretic invariants on their common classifying topos, three levels of bi-interpretability holding for particular classes of formulas: irreducible formulas, geometric sentences, and imaginaries. Lastly, by investigating the classifying topos of the theory of perfect MV-algebras, we obtain various results on its syntax and semantics also in relation to the cartesian theory of the variety generated by Chang’s MV-algebra, including a concrete representation for the finitely presentable models of the latter theory as finite products of finitely presentable perfect MV-algebras. Among the results established on the way, we mention a Morita-equivalence between the theory of lattice-ordered abelian groups and that of cancellative lattice-ordered abelian monoids with bottom element.

Optimized setup for two-dimensional convection experiments in thin liquid films.

We present a novel experimental setup to investigate two-dimensional thermal convection in a freestanding thin liquid film. Such films can be produced in a controlled way on the scale of 5-1000 nm. Our primary goal is to investigate convection patterns and the statistics of reversals in Rayleigh-Bénard convection with varying aspect ratio. Additionally, questions regarding the physics of liquid films under controlled conditions can be investigated, like surface forces, or stability under varying thermodynamical parameters. The film is suspended in a frame which can be adjusted in height and width to span an aspect ratio range of Γ = 0.16-10. The top and bottom frame elements can be set to specific temperature within T = 15 °C to 55 °C. A thickness to area ratio of approximately 10(8) enables only two-dimensional fluid motion in the time scales relevant for turbulent motion. The chemical composition of the film is well-defined and optimized for film stability and reproducibility and in combination with carefully controlled ambient parameters allows the comparison to existing experimental and numerical data.

Determination of the Mass Absorption Coefficient in Two-Layer Ti/V and V/Ti Thin Film Systems by the X-Ray Fluorescence Method

A new XRF procedure for the determination of the mass absorption coefficient in thin film Ti/V and V/Ti two-layer systems has been proposed. The procedure uses easy-to-make thin-film layers of sputtered titanium and vanadium on a polymer film substrate. Correction coefficients have been calculated that take into account attenuation of primary radiation of the X-ray tube, as well as attenuation of the spectral line of the bottom layer element in the top layer.

Hydrogeomorphic controls on hyporheic and riparian transport in two headwater mountain streams during base flow recession

AbstractSolute transport along riparian and hyporheic flow paths is broadly expected to respond to dynamic hydrologic forcing by streams, aquifers, and hillslopes. However, direct observation of these dynamic responses is lacking, as is the relative control of geologic setting as a control on responses to dynamic hydrologic forcing. We conducted a series of four stream solute tracer injections through base flow recession in each of two watersheds with contrasting valley morphology in the H.J. Andrews Experimental Forest, monitoring tracer concentrations in the stream and in a network of shallow riparian wells in each watershed. We found hyporheic mean arrival time, temporal variance, and fraction of stream water in the bedrock‐constrained valley bottom and near large roughness elements in the wider valley bottom were not variable with discharge, suggesting minimal control by hydrologic forcing. Conversely, we observed increases in mean arrival time and temporal variance and decreasing fraction stream water with decreasing discharge near the hillslopes in the wider valley bottom. This may indicate changes in stream discharge and valley bottom hydrology control transport in less constrained locations. We detail five hydrogeomorphic responses to base flow recession to explain observed spatial and temporal patterns in the interactions between streams and their valley bottoms. Models able to account for the transition from geologically dominated processes in the near‐stream subsurface to hydrologically dominated processes near the hillslope will be required to predict solute transport and fate in valley bottoms of headwater mountain streams.

Роль сдвиговой компоненты деформации при сварке давлением образцов из разнородных литых и деформируемых сплавов на основе никеля

A material plastic flow finite-element modeling during pressure welding (PW) of two-element and three-element samples was carried out for dissimilar wrought (EP975) and cast intermetallic (VKNA-type) alloys at 1125°C and 10-4 s-1 initial strain rate. The finite-element modeling was performed in a two-dimensional set-up (plane strain). In the two-element samples case, the top element was ultrafine grained EP975 and the bottom one was VKNA-25. The top and bottom elements of the three-element samples were made from VKNA-25 while the intermediate element was ultrafine-grained EP975. The geometry in the X and Y directions were 40.5 and 5 mm for the EP975 samples and 40.5 and 3 mm for the VKNA-25 samples respectively. Experiments on PW intermetallic Ni3Al alloy and heat-resistant nickel alloy EP975 with ultrafine-grained (UFG) structure were carried out. Samples were parallelepipeds of size 10x40x3 mm3 and 10x40x5 mm3 respectively. PW was carried out at 1125 ˚C. Several combinations of welded sample surfaces with flat and grooved relief were considered. The relief made on both welded surfaces was equivalent to increase of friction between them. This results in a shear deformation reduction near the contact surfaces and degrades the welding quality as compared to the flat surfaces conventional welding. Relief applied only to one of the elements being welded results in a more efficient welding process since active deformation zones are created in the central zone, where in the other samples stagnant zones are observed. There are no deformation peculiarities in PW of the three-element samples, compared to two-element sample.

Locally Quasi-Convex Compatible Topologies on a Topological Group

For a locally quasi-convex topological abelian group (G,τ), we study the poset \(\mathscr{C}(G,τ)\) of all locally quasi-convex topologies on (G) that are compatible with (τ) (i.e., have the same dual as (G,τ) ordered by inclusion. Obviously, this poset has always a bottom element, namely the weak topology σ(G,\(\widehat{G})\) . Whether it has also a top element is an open question. We study both quantitative aspects of this poset (its size) and its qualitative aspects, e.g., its chains and anti-chains. Since we are mostly interested in estimates ``from below'', our strategy consists of finding appropriate subgroups (H) of (G) that are easier to handle and show that \(\mathscr{C} (H)\) and \(\mathscr{C} (G/H)\) are large and embed, as a poset, in \(\mathscr{C}(G,τ)\). Important special results are: (i) if \(K\) is a compact subgroup of a locally quasi-convex group \(G\), then \(\mathscr{C}(G)\) and \(\mathscr{C}(G/K)\) are quasi-isomorphic (3.15); (ii) if (D) is a discrete abelian group of infinite rank, then \(\mathscr{C}(D)\) is quasi-isomorphic to the poset \(\mathfrak{F}_D\) of filters on D (4.5). Combining both results, we prove that for an LCA (locally compact abelian) group \(G \) with an open subgroup of infinite co-rank (this class includes, among others, all non-σ-compact LCA groups), the poset \( \mathscr{C} (G) \) is as big as the underlying topological structure of (G,τ) (and set theory) allows. For a metrizable connected compact group \(X\), the group of null sequences \(G=c_0(X)\) with the topology of uniform convergence is studied. We prove that \(\mathscr{C}(G)\) is quasi-isomorphic to \(\mathscr{P}(\mathbb{R})\) (6.9).

Relationships among triple bottom line elements

Purpose– The purpose of this paper is to gain more insight of the nature and strength of relationships among the three triple bottom line (TBL) outcomes, namely corporate environmental performance outcome (CEPO), corporate social performance outcome (CSPO) and corporate financial performance outcome (CFPO) and to evolve a roadmap for integrating sustainable business practices that facilitates in managing and improving their sustainable performance. Literature reports that currently businesses try to achieve economic, social and ecological goals independently resulting in silos. The interrelationships of TBL elements have not been explored and integrated. The literature has already pointed out that to achieve corporate sustainability, managers need to integrate TBL goals in all their business decisions. However, the question remains – how to integrate these three competing goals and this paper attempts to answer this question.Design/methodology/approach– In the research design, the authors use a quantitative research methodology with data collected by means of a survey questionnaire that included both descriptive and exploratory flavour. The empirical study examines the relationships of TBL elements as perceived by 85 different Australian-based large, medium, as well as small business organisations. The data collected were analysed by performing factor analysis on 21 items resulting in three latent factors that were aligned to TBL outcomes and the correlations among them were analysed to assess their interrelationships.Findings– The results of the study report weak, positive relationships existing between the TBL. This result has useful implications well-supported by the qualitative feedback. The paper argues that Australian managers do not see any strategic advantage in pursuing “beyond compliance” sustainable business practices, as they perceive no added value to their organisations’ financial performance outcomes. Integrating economic, social and ecological performances is seen as an additional management burden.Originality/value– While most of the TBL studies conducted worldwide focus on predominantly assessing large organisations toward responsible and sustainable business practices, this paper considers large, medium as well as small businesses. Also, economic, social and environmental issues are explored by organisations individually, while this study investigates their inter-connections. Through the empirical study, this paper provides recommendations and proposes a four-step roadmap with the participation of quality circles that would facilitate the integration of the social responsibility and environment protection practices into the core business operations paving way towards achieving corporate sustainability.

Drape simulation using solid-shell elements and adaptive mesh subdivision

In this paper, 4-node quadrilateral and 3-node triangular solid-shell elements are applied to drape simulations. With locking issues alleviated by the assumed natural strain method and plane-stress enforcement, static and dynamic drape problems are attempted by the quadrilateral element. If the drape is deep and the mesh density is inadequate, non-realistic sharp folds are predicted due to the non-physical interpenetration of top and bottom element surfaces. To avoid the interpenetration, a reversible adaptive subdivision based on the 1–4 splitting method is developed. To ensure displacement compatibility among elements at different subdivision levels, macro-transition elements are formed by quadrilateral and triangular solid-shell elements. To reduce the dynamic oscillation induced by newly inserted nodes, the discrete Kirchhoff condition is employed to determine the related nodal variables. Dynamic drape examples using adaptive meshing are presented. It can be seen that the predictions look realistic and deep drapes can be predicted with the interpenetration avoided yet the required number of nodes can be kept relatively small.

Corporate sustainability: an IS approach for integrating triple bottom line elements

Purpose – The purpose of this paper is to investigate the inter-relationships among three triple bottom line (TBL) outcomes of corporate sustainability, namely, corporate environmental performance outcome (CEPO), corporate social performance outcome (CSPO) and corporate financial performance outcome (CFPO), with the aid of an empirical study conducted in Australian businesses. The paper also aims to provide a roadmap for integrating sustainable business practices using information systems (IS) approach of continuous improvement lifecycle. Current business practices try to achieve economic, social and ecological goals independently as silos due to the individual operational challenges posed by each of these TBL principles. Design/methodology/approach – The research design mainly adopts a quantitative research methodology with data collected by means of a survey questionnaire that included both descriptive and exploratory flavour. The empirical study examines the relationships of TBL elements as perceived by 85 different Australian-based large, medium as well as small business organisations. The data collected were analysed by performing factor analysis on 21 items, resulting in three latent factors that were aligned to TBL outcomes and the correlations among them were analysed to assess their inter-relationships. Findings – The results of the study report weak and positive relationships existing between the TBL elements, with insights gained through the study leading towards useful implications that are well-supported by the qualitative feedback. The empirical study has also resulted in providing practical recommendations and an implementation framework consisting of a four-step roadmap with the participation of quality circles within an IS approach. Practical implications – The study focuses on inter-relationships and integration of TBL elements in Australian businesses. This could be extended to other businesses in different countries. The proposed roadmap with a continuous improvement cycle of system implementation steps facilitates any organisation to adopt an incremental integration of the social responsibility and environment protection practices within its core business operations for achieving corporate sustainability. Originality/value – While most of the TBL studies conducted worldwide focus on predominantly assessing large organisations towards responsible and sustainable business practices, this paper considers large, medium and small businesses. The research methodology adopted in this study as well as the proposed IS approach with quality circles add value to a growing body of literature with a recent increasing focus on integrated approaches for corporate sustainability.

Optimising apodized grating couplers in a pure SOI platform to -0.5 dB coupling efficiency.

We present a theoretical optimisation of 1D apodized grating couplers in a "pure" Silicon-On-Insulator (SOI) architecture, i.e. without any bottom reflector element, by means of a general mutative method. We perform a comprehensive 2D Finite Difference Time Domain study of chirped and apodized grating couplers in 220 nm SOI, and demonstrate that the global maximum coupling efficiency in that platform is capped to 65% (-1.9 dB). Moving to designs with thicker Si-layers, we identify a new record design in 340 nm SOI, with a simulated coupling efficiency of 89% (-0.5 dB). Going to thicker Si layers does not further improve the efficiency, implying that -0.5 dB may be a global maximum for a grating coupler in SOI without a bottom-reflector. Even after allowing for 193 nm UV-lithographic fabrication constraints, the 340 nm design still offers -0.7 dB efficiency. These new apodized designs are the first pure SOI couplers compatible with deep-UV lithography to offer better than -1 dB insertion losses. With only very minor changes to existing deposition and lithography recipes, they are compatible with the multi-project wafer runs already offered by Si-Photonics foundries.

Free and Cofree Acts of Dcpo-Monoids on Directed Complete Posets

In this paper, we study the existence of the free and cofree objects in the categories Dcpo-\(S\) (and Cpo-\(S\)) of all directed complete posets (with bottom element) equipped with a compatible right action of a dcpo-monoid (cpo-monoid) \(S\), with (strict) continuous action-preserving maps between them. More precisely, we consider all forgetful functors between these categories and the categories Dcpo of dcpo’s, (CPo) of cpo’s, Pos of posets, and Set of sets, and study the existence of their left and right adjoints.