bluuebunny/crossref_metadata_2025 huggingface dataset:
Calculation and Optimization of Heat Transfer between the Low Exergy Heat Source and Organic Rankine Cycle Applied to Heat Recovery Systems
Authors: Smoleń Sławomir , Boertz Hendrik
Published: December 2013

One of the key challenges on the area of energy engineering is the system development for increasing the efficiency of primary energy conversion and use. An effective and important measure suitable for improving efficiencies of existing applications and allowing the extraction of energy from previously unsuitable sources is the Organic Rankine Cycle. Applications based on this cycle allow the use of low temperature energy sources such as waste heat from industrial applications, geothermal sources, biomass, fired power plants and micro combined heat and power systems.Working fluid selection is a major step in designing heat recovery systems based on the Organic Rankine Cycle. Within the framework of the previous original study a special tool has been elaborated in order to compare the influence of different working fluids on performance of an ORC heat recovery power plant installation. A database of a number of organic fluids has been developed. The elaborated tool should create a support by choosing an optimal working fluid for special applications and become a part of a bigger optimization procedure by different frame conditions. The main sorting criterion for the fluids is the system efficiency (resulting from the thermo-physical characteristics) and beyond that the date base contains additional information and criteria, which have to be taken into account, like environmental characteristics for safety and practical considerations.The presented work focuses on the calculation and optimization procedure related to the coupling heat source – ORC cycle. This interface is (or can be) a big source of energy but especially exergy losses. That is why the optimization of the heat transfer between the heat source and the process is (besides the ORC efficiency) of essential importance for the total system efficiency.Within the presented work the general calculation approach and some representative calculation results have been given. This procedure is a part of a complex procedure and program for Working Fluid Selection for Organic Rankine Cycle Applied to Heat Recovery Systems.
Experimental and Numerical Investigation of Thin Liquid Layers at Curved Solid Edges
Authors: Sommer Oliver , Moller Daniel , Wozniak Günter
Published: December 2013

The knowledge of the behavior of thin liquid layers on solid surfaces is of fundamental interest as far as basic research or applications like technical coating or lubrication processes are concerned. The subject is currently getting more important, particularly due to the increasing requirements of thin liquid layer functionalities. We therefore studied the development of the liquid layer thickness distribution field as well as the liquid layer disturbance propagation on a plane solid surface in the vicinity of a curved solid surface experimentally and numerically using LIF (Laser-induced Fluorescence) and CFD (Computational Fluid Dynamics), respectively. The investigation focusses on the influence of the initial layer thickness and solid surface curvature as well as liquid properties like viscosity and surface tension on the film behavior, especially close to solid edges. Experimental and numerical results are shown pointing out relevant quantities for disturbance propagation and validation.
Plasticity and Microstructure of Magnesium - Lithium Alloys
Authors: Kuc Dariusz , Hadasik Eugeniusz , Mizera Jaroslaw , Mikuszewski Tomasz
Published: December 2013

The article presents the results of tests connected with influence of strain parameters on the susceptibility to hot working of magnesium lithium alloys with lithium content of 7.5% mass. Plasticity tests were conducted in compression test from room temperature up to 400°C with strain rate of 0.1s-1. Conducted tests allowed for determination of susceptibility of magnesium alloys with different lithium content to hot working. The results were compared with typical alloy AZ31. The results of influence of deformation temperature on the microstructure of tested alloys are also presented in this paper.
Synergistic Influence of the Addition of Al, Ni and Pb to a Zinc Bath upon Growth Kinetics and Structure of Coatings
Authors: Kania Henryk , Liberski Piotr
Published: December 2013

In this paper the current knowledge about the influence of alloy additions used in galvanizing baths has been analysed. The optimum concentration of Al, Ni and Pb addition has been established. Tests have been conducted to determine the synergistic influence of the addition of AlNiPb in a zinc bath upon the structure and growth kinetics of coatings. The structure and the chemical composition of coatings obtained on steel with low silicon contents and on Sandelin steel have been developed. It has been determined that the synergistic influence of the AlNiPb addition effectively lowers the reactivity of Sandelin steel and it improves zincs flowing off the product surface which results in decreased zinc consumption and better appearance of the coating. The structure of coatings obtained in a Zn-AlNiPb bath on Sandelin steel is similar to the structure of coatings obtained on low-silicon steel.
TEM and X-Ray Examinations of Intermetallic Phases and Carbides Precipitation in an Fe-Ni Superalloy during Prolonged Ageing
Authors: Ducki Kazimierz J. , Mendala Jacek , Wojtynek Lilianna
Published: December 2013

The influence of prolonged ageing on the precipitation process of the secondary phases in an Fe-Ni superalloy of A-286 type has been studied. The samples were subjected to a solution heat treatment at 980°C for 2 h and water quenched, and then aged at temperatures of 715, 750 and 780°C at holding times from 0.5 to 500 h. Structural investigations were conducted using TEM and X-ray diffraction methods. The X-ray phase analyses performed on the isolates were obtained by anodic dissolution of the solid samples. After solution heat treatment the alloy has the structure of twinned austenite with a small amount of undissolved precipitates, such as carbide TiC, carbonitride TiC0.3N0.7, nitride TiN0.3, carbosulfide Ti4C2S2, Laves phase Ni2Si, and boride MoB. The application of ageing causes precipitation processes of γ-Ni3(Al,Ti), G (Ni16Ti6Si7), η (Ni3Ti), β (NiTi) and σ (Cr0.46Mo0.40Si0.14) intermetallic phases, as well as the carbide M23C6. It was found that the main phase precipitating during alloy ageing was the γ intermetallic phase.
Resistance to Electrochemical Corrosion under Conditions of Sterilisation of Guide Wires Used in Endourological Treatment
Authors: Przondziono Joanna , Walke Witold
Published: December 2013

The influence of surface modification and steam sterilisation process on the corrosion characteristics of wires made of X10CrNi18-8 steel used for production of guide wires in endourological treatment was analysed in the study. Corrosion tests were made in artificial urine solution with application of electrochemical testing system VoltaLab PGP201. Resistance to pitting corrosion was evaluated on the ground of registered anodic polarisation curves by means of potentiodynamic method. The tests comprised wires with surface that was ground, electrochemically polished and chemically passivated. Steam sterilisation was performed in autoclave Basic Plus by Mocom. The tests proved that surface modification improved corrosion characteristics of the wire to a great extent. The best corrosion resistance in artificial urine was observed in wire whose surface was successively ground, polished and chemically passivated. It was also proved that chemical passivation process has a favourable impact on corrosion resistance improvement under sterilisation conditions.
Corrosion Resistance of Zn-31AlMg Coatings Obtained by Batch Hot Dip Method
Authors: Kania Henryk , Bierońska Marzena
Published: December 2013

In the paper the authors present the results of corrosion resistance tests on coatings obtained in zinc-aluminium baths with the addition of Mg by use of the batch hot dip method. The content of Al in the bath was 31%, while the content of magnesium was 3 and 6%. In order to define corrosion resistance, two standard corrosion tests were performed in neutral salt spray and inmoist atmosphere containing sulphur dioxide. Corrosion resistance of tested pieces was compared with the corrosion resistance of a traditional zinc coating. It was established that Zn-31AlMg coatings have very good corrosion resistance in the tested environments, better than that of zinc coatings.
Classification and Assessment of Environmental Aspects of Converter and Electric Steel Plants
Authors: Gajdzik Bożena , Wyciślik Andrzej , Janiszewski Krystian
Published: December 2013

The topic of this publication is classification and assessment of environmental aspects in metallurgical enterprise on an example of steel plant. The analysis included aspects which have negative influence on the environment. Taking into account the structure of the proceedings of the process of melting steel in converter and electric furnaces there were key aspects established which are treated as priority in investment programs and current activities within environmental protection process in order to limit their negative influence on the environment. The publication proposes a method of acting in the assessment of environmental aspects for each type of steel plant. The publication can be useful for the engineers and technologies from staff and to services taking care of environmental protection in metallurgical enterprises.
The Influence of Slenderness Ratios of Multi-Hole Ceramic Filters from SF - 1.67 to SF - 8.36 of Filter Surface on Efficiency of Liquid Steel Refining from Non-Metallic Phase
Authors: Janiszewski Krystian , Gajdzik Bożena , Wyciślik Andrzej
Published: December 2013

We propose in this publication the introduction of new, additional definition describing the multiple orifice ceramic filters used in research works on the liquid steel filtrations, calling this the filter slenderness ratio. In order to confirm the theoretical assumptions we have performed a series of the laboratory scale experiments (for the filter slenderness ratio SF - 1.67 to SF - 8.36). The influence of the filter slenderness on the filtration process efficiency has been determined through variations in quantities and surface shares of the non-metallic phase in the filtrated steel in relation to the non-filtered steel. We present also the results of researches on the separating surfaces between the liquid steel and the ceramic filter material, which in form of photos and scanning microscope microanalyses are put together in the publication.
Nucleation and Growth of Primary Silicon Crystals in AlSi Alloy after Modification with CuP and Overheating to a Temperature of 920°C
Authors: Piątkowski Jaroslaw
Published: December 2013

The article describes the process of crystallization of an AlSi17Cu5 (the A3XX.X series according to ASTM standard) alloy which has been modified with 0.05 wt. % P (CuP10 master alloy) and overheated to a temperature of 920°C. It has been shown that, so-called, "time-temperature treatment" (TTT) of alloy in the liquid state, which consists in overheating the alloy to a temperature above Tliq (about 250-300°C), holding at this temperature and rapid cooling, alters the morphology of primary silicon crystals. By the ATD method of thermal analysis, the characteristic temperature of crystallization (Tliq., TEmin., TEmax., TE(Cu), TE(Fe), Tsol.) were determined, and exothermic effects of the modifier and high-degree overheating on the crystallization course of the investigated alloy were examined. A new mechanism of proeutectic crystallization of the a(Al, Me=Cu, Fe) dendrites was proposed. The course of this process is dynamic enough to promote, due to local undercooling, the evolution of heat, which in the ATD curve appears as a well visible additional exothermic effect designated as TX. It is due to the presence in the liquid alloy of microregions with varied content of dissolved silicon.
Analysis of Cracking Process in Conditions of High-Temperature Creep of Castings Form the Modified Superalloy IN-713C
Authors: Cieśla Marek , Binczyk Franciszek , Mańka Marcin
Published: December 2013

mpact of complex modification and filtration during pouring into moulds on durability has been evaluated in this study in conditions of high-temperature creep of castings made from nickel superalloy IN-713C post production rejects. The conditions of initiation and propagation of cracks in the specimens were analysed with consideration of morphological properties of material macro-, micro-and substructure. It has been demonstrated that in conditions of high-temperature creep at temperature 980°C with stress σ =150 MPa creep resistance of the IN-713C superalloy increases significantly with the increase of macrograin size. Creep resistance of specimens made of coarse grain material was significantly higher than the resistance of fine grain material.
Physical and Mechanical Properties of Composites with Aluminum Alloy Matrix Designed for Metal Forming
Authors: Myalski Jerzy , Wieczorek Jakub , Płachta Adam
Published: December 2013

The change of matrix and usage of the aluminum alloys designed for the metal forming in making the composite suspension allows to extend the processing possibility of this type of materials. The possibility of the metal forming of the composites obtained by mechanical mixing will extend the range of composite materials usage. Applying of the metal forming e.g. matrix forging, embossing, pressing or rolling, will allow to remove the incoherence of the structure created while casting and removing casting failures. In order to avoid the appearance of the casting failures the homogenization conditions need to be changed. Inserting the particles into the matrix influences on the shortening of the composite solidification. The type of the applied particles influenced the sedimentation process and reinforcement agglomeration in the structure of the composite. Opposite to the composites reinforced with one-phase particles applying the fasess mixture (glassy carbon and silicon carbide) triggered significant limitation in the segregation process while casting solidification. Inserting the particles into the AW-AlCu2SiMn matrix lowers the mechanical properties tension and impact value strength. The most beneficial mechanical properties were gained in case of heterofasess composites reinforced with the particle mixture of SiC and glass carbon. The chemical composition of the matrix material (AW-AlCu2SiMn) allows to increase additionally mechanical characteristics by the precipitation hardening reached through heat casting forming.
Influence of Deformation Parameters on the Structure in Selected Intermetallic from Al-Fe Diagram
Authors: Jabłońska Magdalena , Kuc Dariusz , Bednarczyk Iwona
Published: December 2013

Department of Materials Science at Silesian University of Technology since 10 years conducts researches to learn about the structural phenomena which occur during hot plastic treatment which are aimed at elaboration of a technology of heat and plastic treatment of selected alloys from Al-Fe diagram. The iron aluminides have been among the most widely studied intermetallics because their low cost, low density, good wear oxidation and corrosion resistance, to create wide prospects for their industrial applications, for components of machines working at a high temperature and in corrosive environment. The problem limiting their application is low plasticity and brittle cracking susceptibility. Consequently, the research of intermetallic-phase based alloys focuses on their plasticity. For the development of thermo-plastic treatment technology, it is necessary to determine internal variables describing the structure of an alloys being deformed is the inhomogeneity, grain size, as well as the grains misorientation angles and texture. The paper presents the course of structural changes of Fe-38Al with Zr, B Mo and C additions under the influence of hot plastic deformation with application of a few different temperatures of the process with given speed of deformation. For the structure and substructure investigations were used a light microscopy and transmission electron microscopy.
High Manganese TWIP Steel - Technological Plasticity and Selected Properties
Authors: Jabłońska Magdalena , Niewielski Grzegorz , Kawalla Rudolf
Published: December 2013

Over the last few years national as well as international research centres conducting research on the development of high-manganese steels. Some of these materials belong to the group of AHS steels, are characterized by the twinning induced plasticity (TWIP) effect which is a new type of steel possessing together with high strength a great plastic elongation, and an ideal uniform work hardening behavior. It is therefore a good candidate for deep drawing applications in the automobile and railway industry. The article presents the results of researches of TWIP-type austenitic steel in case of determination some of the more important parameters for continuous casting simulation process and the results of tests regarding the influence of strain parameters on sensitivity to plastic forming and deformation strengthening. It has been shown that the researched steel reaches a zero plasticity temperature at 1250°C. The deformation tests indicate its good workability of hot processing within the temperature range of 1100 ÷ 800°C. The relation between yield stress and strain during the hot deformation is typical for the presence of dynamic recrystallization processes. The tested steel has good formability and high mechanical properties, especially when being deformed at a high strain rate. Analysis of the substructure of researched steel was indicate presence of mechanical twinning.
Welding of Steel with High Manganese and Aluminum Content
Authors: Lalik Stanisław , Niewielski Grzegorz
Published: December 2013

The paper presents results of tests of mechanical properties, hardness measurements, macro-and microstructures of welded joints austenitic and austenitic-ferritic steel with high manganese and aluminium content meant for automotive industry. Tests were conducted on flat sheets made of steel X20MnAl18-3 and X55MnAl25-5. Tested welded joints were ruptured in tensile strength test in all cases inside the weld which is connected with lower resistance to stretching of welded joints in comparison with resistance of joined steels. Resistance to stretching of tested samples, regardless of the method of welding, is on a similar level.
A parameterization of sub-grid particle formation in sulfur-rich plumes for global- and regional-scale models
Authors: Stevens R. G. , Pierce J. R.
Published: December 2013

Abstract. New-particle formation in the plumes of coal-fired power plants and other anthropogenic sulfur sources may be an important source of particles in the atmosphere. It remains unclear, however, how best to reproduce this formation in global and regional aerosol models with grid-box lengths that are tens of kilometres and larger. Based on the results of the System for Atmospheric Modelling (SAM), a large-eddy simulation/cloud-resolving model (LES/CRM) with online two-moment aerosol sectional (TOMAS) microphysics, we have developed a computationally efficient, but physically based, parameterization that predicts the characteristics of aerosol formed within sulfur-rich plumes based on parameters commonly available in global- and regional-scale models. Given large-scale mean meteorological parameters ((1) wind speed, (2) boundary-layer height and (3) downward shortwave radiative flux), (4) emissions of SO2 and (5) NOx from the source, (6) mean background condensation sink, (7) background SO2 and (8) NOx concentrations, and (9) the desired distance from the source, the parameterization will predict (1) the fraction of the emitted SO2 that is oxidized to H2SO4, (2) the fraction of that H2SO4 that forms new particles instead of condensing onto pre-existing particles, (3) the mean mass per particle of the newly formed particles, and (4) the number of newly formed particles per kilogram SO2 emitted. The parameterization we describe here should allow for more accurate predictions of aerosol size distributions and a greater confidence in the effects of aerosols in climate and health studies.
Aerosol optical properties in Northern Norway and Svalbard
Authors: Chen Y.-C. , Hamre B. , Frette Ø. , Blindheim S. , Stebel K. , Sobolewski P. , Toledano C. , Stamnes J. J.
Published: December 2013

Abstract. We present comparisons between estimates of the aerosol optical thickness and the Ångström exponent in Northern Norway and Svalbard based on data from AERONET (Aerosol Robotic Network) stations at Andenes (69.28° N, 16.01° E, 379 m altitude) and Hornsund (77.00° N, 15.56° E, 10 m altitude) for the period 2008–2011. The four-year annual mean values for the aerosol optical thickness at 500 nm τ(500) at Andenes and Hornsund both were 0.10. At Hornsund, there was less variation of the monthly mean value of τ(500) than at Andenes. The annual mean values of the Ångström exponent α at Andenes and Hornsund were 1.25 and 1.37, respectively. At Andenes and Hornsund α was found to be larger than 1.1 in 64% and 86% of the observations, respectively, indicating that fine-mode particles were dominating at both sites. Both sites had a similar seasonal variation of the aerosol size distribution although one site is in an arctic area while the other site is in a sub-arctic area.
Lytic viral infection of bacterioplankton in deep waters of the western Pacific Ocean
Authors: Li Y. , Luo T. , Sun J. , Cai L. , Jiao N. , Zhang R.
Published: December 2013

Abstract. As the most abundant biological entities in the ocean, viruses can influence host mortality and nutrients recycling mainly through lytic infection. Yet ecological characteristics of virioplankton and viral impacts on host mortality and biogeochemical cycling in the deep sea are largely unknown. In present study, viral abundance and lytic infection was investigated throughout the water column in the western Pacific Ocean. Both the prokaryotic and viral abundance and production showed a significantly decreasing trend from epipelagic to meso- and bathypelagic waters. Viral abundance decreased from 0.36–1.05 × 1010 particles L−1 to 0.43–0.80 × 109 particles L−1, while the virus : prokaryote ratio varied from 7.21–16.23 to 2.45–23.40, at surface and 2000 m depth, respectively. The lytic viral production rates in surface and 2000 m waters were, averagely, 1.03 × 1010 L−1 day−1 and 5.74 × 108 L−1 day−1, respectively. Relatively high percentages of prokaryotic cells lysed by virus in 1000 m and 2000 m were observed, suggesting a significant contribution of viruses to prokaryotic mortality in deep ocean. The carbon released by viral lysis in deep western Pacific Ocean waters was from 0.03 to 2.32 μg C L−1 day−1. Our findings demonstrated a highly dynamic and active viral population in the deep western Pacific Ocean and suggested that virioplankton play an important role in the microbial loop and subsequently biogeochemical cycling in deep oceans.
Interplay of riparian forest and groundwater in the hillslope hydrology of Sudanian West Africa (northern Benin)
Authors: Richard A. , Galle S. , Descloitres M. , Cohard J.-M. , Vandervaere J.-P. , Séguis L. , Peugeot C.
Published: December 2013

Abstract. Forests are thought to play an important role in the regional dynamics of the West African monsoon, through their capacity to extract water from a permanent and deep groundwater table to the atmosphere even during the dry season. It should be the case for riparian forests too, as these streambank forests are key landscape elements in Sudanian West Africa. The interplay of riparian forest and groundwater in the local hydrodynamics was investigated, by quantifying their contribution to the water balance. Field observations from a comprehensively instrumented hillslope in northern Benin were used. Particular attention was paid to measurements of actual evapotranspiration, soil water and deep groundwater levels. A vertical 2-D hydrological modelling approach using the Hydrus software was used as a testing tool to understand the interactions between the riparian area and the groundwater. The model was calibrated and evaluated using a multi-criteria approach (reference simulation). A virtual experiment, including three other simulations, was designed (no forest, no groundwater, neither forest nor groundwater). The model correctly simulated the hydrodynamics of the hillslope regarding vadose zone dynamics, deep groundwater fluctuation and actual evapotranspiration dynamics. The virtual experiment showed that the riparian forest transpiration depleted the deep groundwater table level and disconnected it from the river, which is consistent with the observations. The riparian forest and the deep groundwater table actually form an interacting transpiration system: the high transpiration rate in the riparian area was shown to be due to the existence of the water table, supplied by downslope lateral water flows within the hillslope soil layer. The simulated riparian transpiration rate was practically steady all year long, around 7.6 mm d−1. This rate lies within high-end values of similar study results. The riparian forest as simulated here contributes to 37% of the annual hillslope transpiration, and reaches 57% in the dry season, whereas it only covers 5% of the hillslope area.
A practical scheme to introduce explicit tidal forcing into an OGCM
Authors: Sakamoto K. , Tsujino H. , Nakano H. , Hirabara M. , Yamanaka G.
Published: December 2013

Abstract. A practical scheme is proposed to explicitly introduce tides into ocean general circulation models (OGCM). In this scheme, barotropic linear response to the tidal forcing is calculated by the time differential equations modified for ocean tides, instead of the original barotropic equations of an OGCM. This allows for the usage of various parameterizations specified for tides, such as the self-attraction/loading (SAL) effect and energy dissipation due to internal tides, without unintentional violation of the original dynamical balances in an OGCM. Meanwhile, secondary nonlinear effects of tides, e.g., excitation of internal tides and advection by tidal currents, are fully represented within the framework of the original OGCM equations. That is, this scheme drives the OGCM by the barotropic linear tidal currents which are predicted progressively by a tuned tide model, instead of the equilibrium tide potential, without large additional numerical costs. We incorporated this scheme into Meteorological Research Institute Community Ocean Model and executed test experiments with a low-resolution global model. The results showed that the model can simulate both the non-tidal circulations and the tidal motion simultaneously. Owing to the usage of tidal parameterizations such as a SAL term, a root-mean-squared error in the tidal heights is found to be as small as 10.0 cm, which is comparable to that of elaborately tuned tide models. In addition, analysis of the speed and energy of the barotropic tidal currents is found to be consistent with that of past tide studies. The model also showed active excitement of internal tides and tidal mixing. In the future, the impacts of internal tides and tidal mixing should be examined using a model with a finer resolution, since explicit and precise introduction of tides into an OGCM is a significant step toward the improvement of ocean models.
Anticoagulation during and after acute coronary syndrome
Authors: Bode C. , Zirlik A. , Ahrens I.
Published: December 2013

Current antithrombotic therapy in patients with acute coronary syndrome (ACS) comprises antiplatelet and anticoagulant therapy. Dual antiplatelet therapy composed of aspirin plus a third generation P2Y12 inhibitor (prasugrel or ticagrelor) represents the gold standard, while aspirin plus second generation P2Y12 inhibitor (clopidogrel) may be used as an alternative in the presence of contraindications for third generation P2Y12 inhibitors and/or a high risk of bleeding. Unfractionated heparin (UFH) has been the unchallenged mainstay in anticoagulation for ACS for many decades and is still widely used in patients with ACS treated interventionally. Novel alternative parenteral anticoagulant strategies include the low molecular weight heparin enoxaparin and the synthetic pentas-accharide fondaparinux. Both of these agents share advantages over UFH particularly in medically treated patients with ACS not scheduled for PCI. The direct parenteral factor IIa (thrombin) inhibitor bivalirudin, when used as sole anticoagulant in patients with ACS undergoing PCI, is as effective as the regimen of UFH plus GPIIb/IIIa inhibitor in NSTEMI and superior to the latter regimen in patients with STEMI. The novel approach of a long-term low dose factor Xa inhibition with rivaroxaban in the post ACS phase even further reduced cardiovascular mortality in a clinical trial but has yet to be established in daily clinical practice in the setting of third generation P2Y12 inhibitors. This review discusses currently clinically established anticoagulants for the treatment of ACS alongside with novel approaches such as rivaroxaban.
Design and Development of a Bilateral Therapeutic Hand Device for Stroke Rehabilitation
Authors: Rahman Akhlaquor , Al-Jumaily Adel
Published: December 2013

The major cause of disability is stroke. It is the second highest cause of death after coronary heart disease in Australia. In this paper, a post stroke therapeutic device has been designed and developed for hand motor function rehabilitation that a stroke survivor can use for bilateral movement practice. A prototype of the device was fabricated that can fully flex and extend metacarpophalangeal (MCP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints of the fingers, and interphalangeal (IP), metacarpophalangeal (MCP) and trapeziometacarpal (IM) joints of the thumb of the left hand (impaired hand), based on movements of the right hand's (healthy hand) fingers. Out of 21 degrees of freedom (DOFs) of hand fingers, the prototype of the hand exoskeleton allowed fifteen degrees of freedom (DOFs), with three degrees of freedom (DOFs) for each finger and three degrees of freedom (DOFs) for the thumb. In addition, testing of the device on a healthy subject was conducted to validate the design requirements.
Stimulus Pulse-Based Distributed Control for the Locomotion of a UBot Modular Robot
Authors: Zhu Yanhe , Jin Hongzhe , Fan Jizhuang , Cui Jinxiang , Yin Jinchun , Liu Pijun , Zhao Jie
Published: December 2013

A distributed control algorithm based on a stimulus pulse signal is proposed in this paper for the locomotion of a Modular Self-reconfigurable Robot (MSRR). This approach can adapt effectively to the dynamic changes in the MSRR's topological configuration: the functional role of the configuration can be recognized through local topology detection, dynamic ID address allocation and local topology matching, such that the features of the entire configuration can be identified and thereby the corresponding stimulus signals can be chosen to control the whole system for coordinated locomotion. This approach has advantages over centralized control in terms of flexibility and robustness, and communication efficiency is not limited by the module number, which can realize coordinated locomotion control conveniently (especially for configurations made up of massive modules and characterized by a chain style or a quadruped style).
Fabrication of silica moth-eye structures by photo-nanoimprinting using ordered anodic porous alumina molds
Authors: Yanagishita Takashi , Endo Takahide , Nishio Kazuyuki , Masuda Hideki
Published: December 2013

Moth-eye structures composed of an ordered array of tapered SiO2 pillars were fabricated by photo-nanoimprinting using anodic porous alumina as a mold. The formation of SiO2 moth-eye structures was carried out using a photosensitive polysilane solution as a precursor of silica. The SiO2 moth-eye structures formed on the surface of a glass plate effectively suppressed the reflection of incident light.
Embedded Skyrmion Bags in Thin Films of Chiral Magnets
Authors: Yang Luyan , Savchenko Andrii S. , Zheng Fengshan , Kiselev Nikolai S. , Rybakov Filipp N. , Han Xiaodong , Blügel Stefan , Dunin‐Borkowski Rafal E.
Published: July 2024

Magnetic skyrmions are topologically nontrivial spin configurations that possess particle‐like properties. Earlier research has mainly focused on a specific type of skyrmion with topological charge Q = −1. However, theoretical analyses of 2D chiral magnets have predicted the existence of skyrmion bags—solitons with arbitrary positive or negative topological charge. Although such spin textures are metastable states, recent experimental observations have confirmed the stability of isolated skyrmion bags in a limited range of applied magnetic fields. Here, by utilizing Lorentz transmission electron microscopy, the extraordinary stability of skyrmion bags in thin plates of B20‐type FeGe is shown. In particular, it is shown that skyrmion bags embedded within a skyrmion lattice remain stable even in zero or inverted external magnetic fields. A robust protocol for nucleating such embedded skyrmion bags is provided. The results agree perfectly with micromagnetic simulations and establish thin plates of cubic chiral magnets as a powerful platform for exploring a broad spectrum of topological magnetic solitons.
The Role of Interfacial Interactions and Oxygen Vacancies in Tuning Magnetic Anisotropy in LaCrO3/LaMnO3 Heterostructures
Authors: Zhang Xuanyi , Al‐Tawhid Athby H. , Schafer Padraic , Zhang Zhan , Kumah Divine P.
Published: July 2024

The interplay of lattice, electronic, and spin degrees of freedom at epitaxial complex oxide interfaces provides a route to tune their magnetic ground states. Unraveling the competing contributions is critical for tuning their functional properties. The relationship between magnetic ordering and magnetic anisotropy and the lattice symmetry, oxygen content, and film thickness in compressively strained LaMnO3 (LMO)/LaCrO3 (LCO) superlattices is investigated. Mn–O–Cr antiferromagnetic superexchange interactions across the heterointerface result in a net ferrimagnetic magnetic structure. Bulk magnetometry measurements reveal isotropic in‐plane magnetism for as‐grown oxygen‐deficient thin samples due to equal fractions of orthorhombic a+a‐c‐, and a‐a+c‐ twin domains. As the superlattice thickness is increased, in‐plane magnetic anisotropy emerges as the fraction of the a+a‐c‐ domain increases. On annealing in oxygen, the suppression of oxygen vacancies results in a contraction of the lattice volume, and an orthorhombic to rhombohedral transition leads to isotropic magnetism independent of the film thickness. The complex interactions are investigated using high‐resolution synchrotron diffraction and X‐ray absorption spectroscopy. These results highlight the role of the evolution of structural domains with film thickness, interfacial spin interactions, and oxygen‐vacancy‐induced structural phase transitions in tuning the magnetic properties of complex oxide heterostructures.
Observation of Fast Low‐Temperature Oxygen Ion Conduction in CeO2/β"‐Al2O3 Heterostructure
Authors: Zhang Yingbo , Zhu Decai , Zhao Zhonglong , Liu Jiamei , Ouyang Yuzhao , Yu Jiangyu , Liu Zhongqing , Bai Xixi , Wang Nan , Zhuang Lin , Liu Wuming , Zhu Chengjun
Published: July 2024

Semiconductor ion fuel cells (SIFCs) have demonstrated impressive ionic conductivity and efficient power generation at temperatures below 600 °C. However, the lack of understanding of the ionic conduction mechanisms associated with composite electrolytes has impeded the advancement of SIFCs toward lower operating temperatures. In this study, a CeO2/β″‐Al2O3 heterostructure electrolyte is introduced, incorporating β″‐Al2O3 and leveraging the local electric field (LEF) as well as the manipulation of the melting point temperature of carbonate/hydroxide (C/H) by Na+ and Mg2+ from β″‐Al2O3. This design successfully maintains swift interfacial conduction of oxygen ions at 350 °C. Consequently, the fuel cell device achieved an exceptional ionic conductivity of 0.019 S/cm and a power output of 85.9 mW/cm2 at 350 °C. The system attained a peak power density of 1 W/cm2 with an ultra‐high ionic conductivity of 0.197 S/cm at 550 °C. The results indicate that through engineering the LEF and incorporating the lower melting point C/H, there approach effectively observed oxygen ion transport at low temperatures (350 °C), effectively overcoming the issue of cell failure at temperatures below 419 °C. This study presents a promising methodology for further developing high‐performance semiconductor ion fuel cells in the low temperature range of 300–600 °C.
Gasdermin D Mediated Mitochondrial Metabolism Orchestrate Neurogenesis Through LDHA During Embryonic Development
Authors: Ma Hongyan , Jia Huiyang , Zou Wenzheng , Ji Fen , Wang Wenwen , Zhao Jinyue , Yuan Chenqi , Jiao Jianwei
Published: July 2024

Regulatory cell death is an important way to eliminate the DNA damage that accompanies the rapid proliferation of neural stem cells during cortical development, including pyroptosis, apoptosis, and so on. Here, the study reports that the absence of GSDMD‐mediated pyroptosis results in defective DNA damage sensor pathways accompanied by aberrant neurogenesis and autism‐like behaviors in adult mice. Furthermore, GSDMD is involved in organizing the mitochondrial electron transport chain by regulating the AMPK/PGC‐1α pathway to target Aifm3. This process promotes a switch from oxidative phosphorylation to glycolysis. The perturbation of metabolic homeostasis in neural progenitor cells increases lactate production which acts as a signaling molecule to regulate the p38MAPK pathway. And activates NF‐𝜿B transcription to disrupt cortex development. This abnormal proliferation of neural progenitor cells can be rescued by inhibiting glycolysis and lactate production. Taken together, the study proposes a metabolic axis regulated by GSDMD that links pyroptosis with metabolic reprogramming. It provides a flexible perspective for the treatment of neurological disorders caused by genotoxic stress and neurodevelopmental disorders such as autism.
Natural Affinity Driven Modification by Silicene to Construct a “Thermal Switch” for Tumorous Bone Loss
Authors: Chen Yi‐Xing , Luo Yi‐Ping , Hou Xiao‐Dong , Zhang Lei , Wang Tian‐Long , Li Xi‐Fan , Liu Zhi‐Qing , Zhao Jin‐Hui , Aierken Aihemaitijiang , Cai Zhu‐Yun , Lu Bing‐Qiang , Tan Shuo , Zhao Xin‐Yu , Chen Feng , Zhou Zi‐Fei , Zheng Long‐Po
Published: July 2024

Tumorous bone defects present significant challenges for surgical bio‐reconstruction due to the dual pathological conditions of residual tumor presence and extensive bone loss following excision surgery. To address this challenge, a “thermal switch” smart bone scaffold based on the silicene nanosheet‐modified decalcified bone matrix (SNS@DBM) is developed by leveraging the natural affinity between collagen and silicene, which is elucidated by molecular dynamics simulations. Benefitting from its exceptional photothermal ability, biodegradability, and bioactivity, the SNS@DBM “thermal switch” provides an integrated postoperative sequential thermotherapy for tumorous bone loss by exerting three levels of photothermal stimulation (i.e., strong, moderate, and nonstimulation). During the different phases of postoperative bioconstruction, the SNS@DBM scaffold realizes simultaneous residual tumor ablation, tumor recurrence prevention, and bone tissue regeneration. These biological effects are verified in the tumor‐bearing nude mice of patient‐derived tissue xenografts and critical cranium defect rats. Mechanism research prompts moderate heat stimulus generated by and coordinating with SNSs can upregulate osteogenic genes, promote macrophages M2 polarization, and intensify angiogenesis of H‐type vessels. This study introduces a versatile approach to the management of tumorous bone defects.
Low Temperature Fast Mixed OH−/H+ Ionic Conductor in Doped Strontium Cerates
Authors: Zou Peimiao , Iuga Dinu , Brown Alex J. , Han Yisong , Wang Renhang , Tao Shanwen
Published: July 2024

The drawbacks of high temperature solid oxide fuel cells (HT‐SOFCs) prompt efforts to lower operating temperatures to near ambient temperatures (NAT). Here the high mixed OH−/H+ ionic conductivity in doped SrCeO3 below 100 °C is reported. The SrCe0.8Y0.2O3−δ (SCYO20) electrolyte demonstrates a high ionic conductivity of 12 mS cm−1 in water and 9 mS cm−1 in wet air at 60 °C and an excellent long‐term stability over 100 h. Solid state nuclear magnetic resonance confirms the presence of protons and hydroxide ions in the hydrated oxides and their correlation with Y dopant. Demonstration of direct ammonia fuel cells using the SCYO20 electrolyte indicates the practical application value of this material. The OH− conduction of SrCe0.7Sn0.2Y0.1O3−δ (SCSY721) is demonstrated by electrolysis of D2O. The introduction of KOH significantly increases the availability of OH− feed ions, leading to a remarkable improvement of ionic conductivity of SCSY721 electrolyte which is increased by 27 times, 56.34 mS cm−1 in 6 m KOH at 90 °C. The increased ionic conductivity due to the presence of high concentration of extrinsic conducting ions, here are OH− ions, is called as ‘feeding effect’. This study offers new electrolyte materials for cost‐effective, and durable electrochemical devices such as NAT‐SOFCs.
Kernel number and kernel weight stability can vary across corn hybrids
Authors: Kim Jinwook , Sullivan Paul , Caldwell Lindsey , Downey Julia , Hooker David C. , Nasielski Joshua
Published: July 2024

The stability of a trait refers to the extent to which its expression in a given genotype varies across environments. The more stable a trait, the less variable its expression. Grain yield stability is a central consideration in corn production to ensure that hybrids perform consistently across environments and is frequently quantified given its importance. Little attention has been paid to the stability of corn yield components, kernel number per m2 (KN), and kernel weight (KW). Our hypothesis is that while previous research suggests that yield stability of commercial corn hybrids is generally consistent, the stabilities of KN and KW may exhibit significant differences, even when overall yield stability remains constant. This study evaluated the yield and yield component stabilities of 23 commercial corn hybrids conducted on‐farm at five location‐years in Ontario, Canada, using Finlay–Wilkinson regression. Most (61%) hybrids exhibited average yield stability with β1‐values close to 1.0. But seven hybrids displaying average yield stability had KN and/or KW stabilities significantly different than average. While in absolute terms, KW was always more stable than KN across environments, the data indicate that hybrids have different mechanisms to achieve stable yields in terms of relative yield component adjustments. Overall, 14 hybrids had yield component β1‐values significantly more or less stable than average. The instances where yield component β1‐values differed significantly from 1.0 were almost equally divided between KN and KW. These findings support the potential for hybrid‐specific corn management, that is, tailoring management practices to take advantage of hybrid variation in yield component stabilities.
Effects of conservation agriculture technologies on soil macrofauna community attributes in rainfed agriculture system
Authors: Parvizi Yahya , Heshmati Mosayeb , Gheituri Mohammad , Toohidi Mohammadtaghi
Published: July 2024

Inappropriate rainfed crop management, especially wrong tillage and crop residue management, led to reduce the diversity of soil biological quality, especially soil macrofauna community, in semiarid region. This study was conducted to investigate the effect of 5 year conservation agriculture operation techniques on the quality and the diversity indices of soil macrofauna community in the rainfed lands in the west of Iran. This experiment was carried out in the statistical format of split‐split plots based on a randomized completely block design with three replications. The main treatments include control or conventional tillage, compound tillage, chisel tillage, and direct cultivation (no tillage) with three sub‐treatments of plant residues (no residues, one‐third, and two‐thirds of plant residues) in rainfed wheat (Triticum aestivum) rotation with rainfed chickpea (Cicer arietinum). Changes in soil biological quality indicators, such as soil microbial respiration were measured. Also, the indicators related to the population of soil macrofauna, including biodiversity index, uniformity index, and species richness, were measured and the effect of treatments on the measured indicators were compared with the classical statistical method of analysis of variance and Duncan's mean comparison test. The results showed that conservation agricultural treatments, including no‐tillage treatment, have led to significant increase of 19% and 15% of macrofauna biodiversity index in wheat and chickpea, respectively. Also, keeping one‐third of the wheat residues has led to an 18% increase in the biodiversity index of the soil macrofauna during the evaluation period. Biodiversity index and taxonomic richness of soil macrofauna were generally higher in the years of wheat than chickpea, and on the contrary, the species uniformity index of soil macrofauna biological community was higher in chickpea than wheat.
Integrating cover crops and organic amendments to mitigate the limitations of tillage on soil health and cotton productivity
Authors: Ankomah Godfred , Amissah Solomon , Hollifield Stephanie , Habteselassie Mussie Y. , Franklin Dorcas H. , Snider John L. , Kemerait Robert C. , Roberts Philip M. , Sintim Henry Y.
Published: July 2024

Various tillage systems have limitations on soil health, such as the degradation of soil structure and organic matter under conventional tillage (CT) systems, as well as short‐term soil compaction in conservation tillage systems. A 3‐year field experiment was established to evaluate the integration of cover crop (CC) and organic amendments (OAs) into CT and strip tillage (ST) systems, and their impact on soil properties and cotton (Gossypium hirsutum L.) productivity. The CC was cereal rye (Secale cereale), and the combined application of animal manure and biochar constituted the OA. In the third year, differences in soil compaction between the CT and ST systems were observed when the measurements were made after tillage. Moreover, integrating CC and OA under the CT and ST systems increased the soil depth to compaction zones. Soil compaction was observed at 27.5‐cm depth under CT, at 30‐cm depth under CT integrated with CC and OA, at 10‐cm depth under ST, and at 15‐cm depth under ST integrated with CC and OA, using 2 MPa as the threshold. In general, the integration of CC and OA tended to increase soil respiration, organic matter, and available nutrients, but the effects were not consistent across years and soil depth. Despite differences in the various soil health properties, the management systems had minimum impact on cotton productivity and fiber quality, indicating the ST was effective in preparing the seedbed. Moreover, the differences in soil properties were not at yield‐limiting levels within 3 years of the study.