Hybrid Connection Research Articles

Nominal and local stress quantities to design aluminium-to-steel thin welded joints against fatigue

Welding aluminium to steel to make mechanical joints is possible, but there is, to date, no accepted method for performing the fatigue assessment of such hybrid connections. In this context, the present investigation aims at checking the accuracy of nominal stresses, effective notch stresses, notch-stress intensity factors, and the Modified Wöhler Curve method (applied in conjunction with the Theory of Critical Distances) in estimating fatigue lifetime of butt, cruciform, lap and tee aluminium-to-steel thin welded joints. EWM coldArc® welding technology was used to manufacture the welded specimens that were used for this validation exercise. The samples being tested in the structural laboratory of the University of Sheffield, UK, were manufactured by using AA1050 aluminium and EN10130:1991 steel with main plates thicknesses of 1 mm or 2 mm. The results from this experimental/theoretical investigation demonstrate that all the design methodologies being investigated can be used to perform the fatigue assessment of aluminium-to-steel thin welded joints provided that suitable reference/calibration fatigue curves are used. In the present paper, some quantitative recommendations are given for use in situations of practical interest of the design techniques being considered.

Self‐stabilising hybrid connectivity control protocol for WSNs

In this study, the authors address the problem of combining hierarchical and flat techniques to construct and maintain nodes’ connectivity as well as links’ symmetry (bidirectionality) in a wireless sensor network (WSN) comprising static nodes. They propose a localised and asynchronous self-stabilising hybrid message passing a solution that seamlessly merges three well known connectivity control techniques for such ad hoc networks, namely k -hop clustering , power control (transmission range adjustment) and sleep/wake scheduling. Their stigmergy-based strategy (i.e. inspired from ants’ pheromone-based communication, division of labour and swarming behaviours) allows a WSN to simultaneously cope with issues such as scalability, fault tolerance, transmission range minimisation, energy hole problem (i.e. premature node deaths in the vicinity of the sink), channel overhearing and signalisation reduction. To the best of their knowledge, such a solution does not exist in the literature. The few self-stabilising hybrid connectivity control protocols currently proposed use only two of the above-mentioned techniques. The authors formally prove the correctness of their scheme and its self-stabilisation property under an unfair distributed daemon. Simulation results show that the proposed scheme has a low average convergence time, is energy efficient and can prolong network lifetime.

AHCNet: An Application of Attention Mechanism and Hybrid Connection for Liver Tumor Segmentation in CT Volumes

The liver is a common site for the development of primary (i.e., originating from the liver, e.g., hepatocellular carcinoma) or secondary (i.e., spread to the liver, e.g., colorectal cancer) tumor. Due to its complex background, heterogeneous, and diffusive shape, automatic segmentation of tumor remains a challenging task. So far, only the interactive method has been adopted to obtain the acceptable segmentation results of a liver tumor. In this paper, we design an Attention Hybrid Connection Network architecture which combines soft and hard attention mechanism and long and short skip connections. We also propose a cascade network based on the liver localization network, liver segmentation network, and tumor segmentation network to cope with this challenge. Simultaneously, the joint dice loss function is proposed to train the liver localization network to obtain the accurate 3D liver bounding box, and the focal binary cross entropy is used as a loss function to fine-tune the tumor segmentation network for detecting more potentially malignant tumor and reduce false positives. Our framework is trained using the 110 cases in the LiTS dataset and extensively evaluated by the 20 cases in the 3DIRCADb dataset and the 117 cases in the Clinical dataset, which indicates that the proposed method can achieve faster network convergence and accurate semantic segmentation and further demonstrate that the proposed method has a good clinical value.

Effect of different angulations and collar lengths of conical hybrid implant abutment on screw loosening after dynamic cyclic loading

BackgroundThe purpose of this in vitro study was to evaluate the effect of different angulations and collar lengths of the implant abutment on screw loosening by measuring removal torque value (RTV) before and after dynamic cyclic loading using digital torque gauge.MethodsA total 90 sets of 4.5 mm diameter × 10 mm length bone level implants with conical hybrid connection were used. They were divided equally according to abutment angulation, into three groups: GI 0° abutment, GII 15° abutment, and GIII 25°. Each group was divided into two subgroups, 15 each, according to collar height: subgroup A (2 mm) and subgroup B (4 mm). Each implant and abutment assembly was positioned vertically in the center of the acrylic resin block using stainless steel cylindrical split mold. Initial analysis was made by abutment screw tightened with 30 Ncm torque twice with 10-min intervals using a digital torque gauge. RTV before and after cyclic loading of the abutment screws were measured in newton centimeter using digital torque gauge. One hundred thousand cycles of eccentric dynamic cyclic loading, at 130 N at a rate of 1 Hz, were applied 5 mm away from the central axis of the implant fixture. Percentage of removal torque loss (%RTL) before and after dynamic cyclic loading were calculated and statistically analyzed using the SPSS version 20.ResultsFor GI, %initial RTL was 25.0 ± 1.5% and decreased significantly after loading (23.5 ± 2.3%). For GII, %initial RTL was 25.5 ± 1.4% and increased significantly after loading (33.4 ± 3.7%). For GIII, %initial RTL was 25.944 ± 1.2% and increased significantly after loading (40.1 ± 5.1%). There was significant effect on screw loosening for abutment angulations and collar lengths.ConclusionWithin the limitations of this study, results suggested that screw loosening increases with increasing abutment angulations and collar lengths after dynamic cyclic loading.

Star and Delta Hybrid Connection of a FSCW PM Machine for Low Space Harmonics

Fractional-slot concentrated-winding (FSCW) permanent magnet (PM) machines have been widely studied in recent years. This is mainly due to the several advantages, including high power density, high efficiency, short end turns, high fill factor, low cogging torque, good flux-weakening and fault-tolerant performance. However, the key challenges of utilizing FSCW-PM machines are the abundant stator magnetomotive force (MMF) harmonics. In this paper, the multiphase star–delta hybrid connection (SDHC) windings configuration that can eliminate some stator MMF harmonics is systematically studied. First, the general relationship between the number of slots and phases which are appropriate for the SDHC windings configuration is derived. In addition, the particular principle of the MMF harmonics elimination by the SDHC windings configuration is researched. In order to verify the analysis results, four three-phase SDHC FSCW-PM machines with different slot–pole combinations are built and calculated by the finite-element method. Finally, experiments on a prototype three-phase 12-slot ten-pole FSCW-PM machine are carried out for validation.

From Folklore to Multimedia: Repositioning Nigerian Folklore for Cultural Development in a New Technological World

In Nigeria, cultural contents have continued to be explored in relation to their typologies, taxonomies and social value. Some folklore materials are disappearing due to modernisation and globalisation, leaving marginal communities to turn to alien models, some of which are not effective or accessible. The desire for a community-based model is weak as it is considered primitive and inferior to contemporary existence. Folklorists are too few with too little research wherewithal to carry out an extensive and broad-based study on oral art forms and their continued relevance to society. An ironic hybrid and interdisciplinary connectivity exists between folklore and multimedia as cultural materials adopt modern technologies, which an in-depth study could bring to light. This article, using the contextual perspective of analysis, examines ways in which folklore materials could continue to be explored even in their dynamic new multimedia “homes” such as music, photography, moving images, audio, computer, and broadcast media, thus creating new narrative and performance spaces other than the oral and the literary, and a new interface between folklore and modern technology life. The article proposes the undertaking of enhanced research into the hidden dimensions of folklore and the re-fashioning of cultural thought, science and technology, in line with cultural and global trends towards enhanced knowledge and development.

Development of a new hybrid precast beam-to-column connection

This paper presents conceptual design and development of a new hybrid precast beam-to-column connection. The hybrid precast connection is made of steel connection which is embedded in concrete beam and column. The beam and column are connected to each other by bolts connectors. The performance connection is evaluated through the quasi-static test. To aid the aim, the monolithic connection and hybrid connection of the same beam and column size are modeled in 3-dimensions using ABAQUS commercial software. The results of the finite element analysis indicated that the hybrid connection was slightly stiffer than the monolithic connection while the ductility of both connections was similar. In addition, the failure mode of hybrid precast connection followed the strong-column weak-beam concept.

Numerical Investigation of Bolted Hybrid Steel-Timber Connections

Hybrid steel to timber connections are found in many buildings and bridges. These connections offer several advantages such as ease of construction and energy dissipation. This research paper aims to study the mechanical behaviour of bolted hybrid connections that consists of a square hollow steel column (SHS) and a glulam timber beam. The connection between the two structural members is achieved by means of angles and preloaded bolts. A reference model is constructed and verified by comparison to experimental and numerical data from the international literature. Additionally, several parameters that affect the response of the connection are modified in order to investigate and quantify their effect, resulting in seven different case studies. These parameters are the size of the bolts, the thickness of the angles and the addition of stiffener. The moment- rotation curve of each case study is constructed and the results are commented. Finally, a proposed optimal configuration of the hybrid connection is presented.

Metal Chalcogenide Imidazolate Frameworks with Hybrid Intercluster Bridging Mode and Unique Interrupted Topological Structure

Constructing a hybrid connection mode between cluster-based building blocks is of particular importance in the pursuit of fascinating framework structures. Reported here are two new metal chalcogenide imidazolate frameworks (SCIF-11 and SCIF-12) with a hybrid intercluster bridging mode and a unique interrupted topological structure. SCIF-11 has a typical dia topology with a T3-InS supertetrahedral cluster as the node and an imidazolate (IM) ligand as the linker, but it for the first time combines two kinds of intercluster connecting modes: T3-S-T3 and T3-IM-T3. Interestingly, SCIF-12 composed of T4-CdInS supertetrahedral clusters and IM ligands possesses a unique 3,4-connected interrupted framework with ins topology, with this being the first case in the family of cluster-based metal chalcogenide frameworks. This work provides a new strategy on enriching the intercluster bridging modes and topological types of metal chalcogenide frameworks.

Synthesis of multi-row and multi-speed planetary gear mechanism for automatic transmission

The multi-speed planetary gear automatic transmission (AT) can improve the engine fuel economy and the vehicle ride comfort. And multi-speed AT could be achieved by multi-row planetary gear mechanism (PGM). A systematic design method is explored to synthesize the configuration schemes of multi-row and multi-speed AT based on the lever analogy in this paper. Hybrid connection (HC) of 3-row is selected as preferred connection and taken as an example to deduce the synthesis process based on the analysis of connection of 2-row and 3-row PGM. Lever output of the HC of 3-row PGM is analyzed when it is split into a single-row PGM (SPGM) and a double-row parallel PGM (DPGM) lever. SPGM and DPGM lever are properly matched with components. And the matching criterion of DPGM is summarized in light of the infeasible matching schemes. Furthermore, the lever schemes of 3-row PGM AT are synthesized by arranging the power and link elements. It is proved that the lever schemes can be used to design multi-row and multi-speed AT not only for single power vehicle but also for hybrid power vehicle. This paper will provide theoretical reference for design of multi-row and multi-speed AT.

Optimized power management based on adaptive-PMP algorithm for a stationary PEM fuel cell/battery hybrid system

This research develops an efficient and robust polymer electrolyte membrane (PEM) fuel cell/battery hybrid operating system. The entire system possesses its own rapid dynamic response benefited from hybrid connection and power split characteristics due to DC/DC buck-boost converter. An indispensable energy management system (EMS) plays a significant role in achieving optimal fuel economy and in a promising running stability. EMS as an indispensable part plays a significant role in achieving optimal fuel economy and promising operation stability. This study aims to develop an adaptive supervisory EMS that comprises computer-aided engineering tools to monitor, control, and optimize the performance of the hybrid power system. A stationary fuel cell/battery hybrid operating system is optimized using adaptive-Pontryagin's minimum principle (A-PMP). The proposed algorithm depends on the adaptation of the control parameter (i.e., fuel cell output power) from the state of charge (SOC) and load power feedback. The integrated model simulated in a Matlab/Simulink environment includes the fuel cell, battery, DC/DC converter, and power requirements models by analyzing the three different load profiles. Real-time experiments are performed to verify the effectiveness of EMS after analyzing the simulated operating principle and control scheme.

Effect of abutment connection type on crestal bone resorption around implants

Purpose: To test the hypothesis that the type of implant abutment connection configurations may influence the stresses and strains induced in the peri-implant area and affect crestal bone resorption around implants. Materials and Methods: Sixty implants were inserted in forty two male patients (mean age 44 years old) and randomly divided into two groups according to internal hexagon (Legacy™ 2, Implant Direct, USA) and conical hybrid connection (AnyRidge; MEGAGEN, Seoul, Korea). Abutments were connected and restoration delivered four months after implants placement. Each case was evaluated radiographically and linear measurements of bone resorption were made from the implant’s platform to the first point of bone-to-implant contact at baseline (time of restoration delivery), 6,12, 24 and 36 months later. Data were collected, tabulated and statistically analyzed with repeated measures two way ANOVA test. Results: No statistical significant differences were found between the tested groups (P ≥ 0.05). Peri-implant bone changes demonstrated mean bone loss of (1.17 ± 0.58) for Group (1) and (1.12±0.53) for Group (2) after three years of insertion. Conclusions: Despite the limitations of this controlled clinical trial and although no statistical significant differences were found, conical hybrid implant abutment connection showed less crestal bone resorption around implants than internal hexagon implant in short term evaluation. Keywords: implant abutment, internal connection, conical hybrid, crestal bone resorption.This study was conducted at faculty of dentistry, Tanta University, Egypt after the approval of the Ethics committee of the faculty.

Electronic–magnetic gearing motor analyses and simulations for electric vehicles

This study presents an innovative electronic-magnetic geared motor technology for electric vehicles (EVs). The motor has been designed and simulated. The electronic-magnetic gearing (EMG) connects parallel, series or hybrid connections of stator windings into gears to accommodate the different speed and torque demands in the drive cycle. The objective of the EMG is to increase the speed and torque range of the motor and reduce current draw from the batteries. A 1.5 kW prototype EMG motor was built and tested on a test rig at Electronica Products Ltd. A comparison simulation of an EMG motor compared with a traditional permanent magnet synchronous motor was also carried out. The result proves that the theory of EMG is sound and it has great potential for energy efficiency in EVs, especially for the powertrain units.

Characteristics of Honeycomb-Type Oxygen Generator with Electrolyte Based on Doped Bismuth Oxide

An oxygen generator using Y-doped Bi2O3 as electrolyte to transport oxygen ions has been developed, having honeycomb-type structure with dimensions of 40 mm × 35 mm × 30 mm and consisting of 13 × 12 channels. External wire circuitry for the channels arrayed using parallel, series, and hybrid connection was evaluated to achieve the best oxygen separation efficiency. It was observed that the oxygen generator with hybrid connection facilitated evolution of oxygen at maximum of 117 sccm and high purity > 99.9% at 550°C under current flow of 14 A. Addition of 5 wt.% silane and 3 wt.% glass–ceramic powder to the Ag slurry used at both electrodes not only increased the coverage of the metal electrode on the ceramic substrate during dip coating but also prevented cracking at the electrode layer of the module under stress from the electric field and temperature during high-temperature operation, thus reducing the decay rate of the oxygen generator in durability testing.

Scale up sediment microbial fuel cell for powering Led lighting

Sediment microbial fuel cells (SMFCs) are expected to be utilized as a sustainable power source for remote environmental observing 30 day’s investigations of experiment to understand the long-term performance of SMFCs. The point of this investigation is to increase power generation, 8 individual sediment microbial fuel cells is stacked together either in series or in hybrid connection. Two combinations, of the hybrid connection, are proving to be the more effective one, step-up both the voltage and current of the framework, mutually. Polarization curve tests are done for series and hybrid connected sediment microbial fuel cell. The maximum study state voltage and current are obtained 8.150V and 435.25µA from series and 4.078V and 870.75µA hybrid connected SMFC. This study suggests that power of SMFC scale-up by connecting series and hybrid for practical use of the device.Article History: Received : September 26th 2017; Received: December 24th 2017; Accepted: January 4th 2018; Available onlineHow to Cite This Article: Prasad, J and Tripathi, R.K. (2018) Scale Up Sediment Microbial Fuel Cell For Powering Led Lighting. International Journal of Renewable Energy Development, 7(1), 53-58.https://doi.org/10.14710/ijred.7.1.53-58

Microstructuring of joining areas in aluminum alloy sheets by Jet Electrochemical Machining

In this work the increase of the tensile shear strength by means of microstructuring of the metallic part for ultrasonic vibration assisted joining of hybrid compounds is presented. The aluminum alloy EN AW-5083 and a carbon fibre-reinforced plastic (CFRP) from Bond Laminates are used as a material combination. A suitable method is electrochemical processing (ECM). The microstructuring is carried out with continuous electrolyte free jet machining (Jet-ECM): Characteristic of this technology is the restriction of the electric current to a limited area of the electrolyte jet. After describing the materials and sample geometry used, the Jet-ECM technology and the ultrasonic vibration assisted joining process are explained. The strength of the joint is assessed by means of a tensile shear test. The determined results of the tensile shear strength for hybrid connections between microstructured aluminum sheets and CFRP are compared with those of unstructured aluminum sheets. Furthermore, the influence of the microstructure on the tensile shear strength achieved is discussed using metallographic cross-sections of the joining area.

Multiclass Classification of Word Imagination Speech with Hybrid Connectivity Features.

In this study, electroencephalography data of imagined words were classified using four different feature extraction approaches. Eight subjects were recruited for the recording of imagination with five different words, namely; 'go', 'back', 'left', 'right', and 'stop'.

Hybrid connectivity restoration in wireless sensor and actor networks

Wireless sensor and actor networks are becoming more and more popular in the recent years. Each WSAN consists of numerous sensors and a few actors working collaboratively to carry out specific tasks. Unfortunately, actors are prone to failure due to harsh deployment environments and constrained power, which may break network connectivity resulting in disjoint components. Thus, maintaining the connectivity among actors is especially important. This paper proposes hybrid connectivity restoration (HCR), which integrates proactive selection and reactive motion. An actor protectively selects a backup node through its one-hop neighbor table and informs the backup node to supervise its stage. Once it fails, the backup node moves to the best position to restore the connectivity of the failed node’s neighbors reactively. This triggers a local recovery process at the backup node, which is repeated until network connectivity is restored. In order to minimize travel distance, HCR selects the backup node which moves the shortest distance to restore connectivity. Furthermore, HCR opts to reduce the number of messages by just informing the failure to its backup node. The correctness and effectiveness of HCR are validated through both theoretical analysis and simulations.

Mechanical Behavior of Steel Fiber-Reinforced Concrete Beams Bonded with External Carbon Fiber Sheets.

This study investigates the mechanical behavior of steel fiber-reinforced concrete (SFRC) beams internally reinforced with steel bars and externally bonded with carbon fiber-reinforced polymer (CFRP) sheets fixed by adhesive and hybrid jointing techniques. In particular, attention is paid to the load resistance and failure modes of composite beams. The steel fibers were used to avoiding the rip-off failure of the concrete cover. The CFRP sheets were fixed to the concrete surface by epoxy adhesive as well as combined with various configurations of small-diameter steel pins for mechanical fastening to form a hybrid connection. Such hybrid jointing techniques were found to be particularly advantageous in avoiding brittle debonding failure, by promoting progressive failure within the hybrid joints. The use of CFRP sheets was also effective in suppressing the localization of the discrete cracks. The development of the crack pattern was monitored using the digital image correlation method. As revealed from the image analyses, with an appropriate layout of the steel pins, brittle failure of the concrete-carbon fiber interface could be effectively prevented. Inverse analysis of the moment-curvature diagrams was conducted, and it was found that a simplified tension-stiffening model with a constant residual stress level at 90% of the strength of the SFRC is adequate for numerically simulating the deformation behavior of beams up to the debonding of the CFRP sheets.

Hybrid and Subexponential Linear Logics

HyLL (Hybrid Linear Logic) and SELL (Subexponential Linear Logic) are logical frameworks that have been extensively used for specifying systems that exhibit modalities such as temporal or spatial ones. Both frameworks have linear logic (LL) as a common ground and they admit (cut-free) complete focused proof systems. The difference between the two logics relies on the way modalities are handled. In HyLL, truth judgments are labelled by worlds and hybrid connectives relate worlds with formulas. In SELL, the linear logic exponentials (!, ?) are decorated with labels representing locations, and an ordering on such labels defines the provability relation among resources in those locations. It is well known that SELL, as a logical framework, is strictly more expressive than LL. However, so far, it was not clear whether HyLL is more expressive than LL and/or SELL. In this paper, we show an encoding of the HyLL's logical rules into LL with the highest level of adequacy, hence showing that HyLL is as expressive as LL. We also propose an encoding of HyLL into SELL⋒ (SELL plus quantification over locations) that gives better insights about the meaning of worlds in HyLL. We conclude our expressiveness study by showing that previous attempts of encoding Computational Tree Logic (CTL) operators into HyLL cannot be extended to consider the whole set of temporal connectives. We show that a system of LL with fixed points is indeed needed to faithfully encode the behavior of such temporal operators.