bluuebunny/crossref_metadata_2025 huggingface dataset:
Microstructure Similarities between Phases F and U in Al-Pd-Co Alloys
Authors: Černičková Ivona , Adamech Marek , Ďuriška Libor , Drienovsky Marian , Janičkovič Dusan , Priputen Pavol , Janovec Jozef
Published: December 2016

The work is aimed at searching for compositionally variant isostructural mutations of the cubic F-phase in both as-annealed (850°C/500 h) and DTA-cooled conditions of the Al72Pd9Co19 alloy. Recently, the mutations were reported for the U-phase in the Al69.8Pd13.8Co16.4 alloy annealed at 700°C for 2000 h. In the investigation, scanning electron microscopy including energy dispersive X-ray spectroscopy, powder X-ray diffraction, and differential thermal analysis (DTA) were used. Two isostructural mutations of the F-phase, FL (the product of L-parent) and FV (the product of V-parent), were identified (symbol L stands for liquid). On DTA-cooling, the bivariant heterogeneous transition (Lpart→V), the monovariant heterogeneous transformation (Lrest→V+FL), and the monovariant quasi-eutectoid transformation (Vrest→Al5Co2+FV) were recorded.
AFM Study of Microstructure Role in the Cyclic Plasticity of Martensitic Steel
Authors: Seidametova Gulzar , Vogt Jean Bernard , Proriol Serre Ingrid
Published: December 2016

The paper presents the description of FSMs (fatigue slip markings) and the evaluation of cyclic plasticity markings of a 12%Cr martensitic steel by AFM surface analyses. The microstructure of a 12%Cr martensitic steel, quenched and tempered in air, consists of prior austenite grains, packets, blocks, and laths. The low cycle fatigue (LCF) test at a total strain range Δεt=1.2% was interrupted at different life fractions for the surface relief investigation by AFM. The localization of FSMs relatively to the different microstructural interfaces of the studied steel was proposed. The principal FSMs, appeared in the first fatigue cycle, are likely to be localized at the packet and block boundaries, while the secondary one (appeared later at 44% of lifetime) are at the lath boundaries or in the laths. The height of principal and secondary FSMs increases constantly during LCF cycling.
Measurement of the Porosity of Additive-Manufactured Al-Cu Alloy Using X-Ray Computed Tomography
Authors: Zatočilová Aneta , Zikmund Tomáš , Kaiser Jozef , Paloušek David , Koutný Daniel
Published: December 2016

The additive manufacturing of metallic parts by means of selective laser melting is an emerging technology, the development of which is currently of great interest. The quality of the parts produced is evaluated mainly in terms of their mechanical properties, dimensional accuracy, and the homogeneity of the material. Because it is virtually impossible to produce parts without any internal porosity using powder-based additive manufacturing processes, measuring the porosity is critically important to optimizing the processing parameters. X-ray computed tomography is currently the only way used to measure the distribution of pores non-destructively and it can also measure the density and dimensional accuracy. Many studies have presented results of porosity measurements made using CT, but no standard methodology for the making of measurements and processing of data currently exists. The choice of parameters used for measurement and processing can have a significant impact on the results. This study focuses on the effect of voxel resolution on the resulting porosity number and discusses the possibilities for determining the threshold value for detecting pores. All the results presented in this study were obtained by analyzing the sample produced by selective laser melting technology from AlCu2Mg1.5Ni alloy.
Sample Geometry and the Brittle-Ductile Behavior of Edge Cracks in 3D Atomistic Simulations by Molecular Dynamics
Authors: Pelikán Vladimír , Hora Petr , Machová Anna , Kolman Radek , Uhnáková Alena
Published: December 2016

We present new results of molecular dynamic (MD) simulations in 3D bcc iron crystals with edge cracks (001)[010] and (-110)[110] loaded in mode I. Different sample geometries of SEN type were tested with negative and positive values of T-stress according to continuum prediction by Fett.
Effective Elastic Properties of 3D Composites with Short Curvilinear Fibers: Numerical Simulation and Experimental Validation
Authors: Mykhas'kiv Victor V. , Stasyuk Bohdan M.
Published: December 2016

Theoretical and experimental estimation of elastic properties of two-phase composites containing matrix material and arc-shaped cylindrical fibers is given. Theoretical aspect consists in hybrid micro-macro formulation of problem with consideration of two associated subproblems –nume­rical simulation of fiber influence on the representative volume element and effective strain-stress field approximation by the averaging procedures. Boundary element method is applied for the solution of micro-level subproblem as well as Mori-Tanaka model is adopted for the overall description of composite properties at the macro-level. Then interfacial displacements are involved into solution scheme only. The effective elastic moduli of arc-fiber-reinforced composites are analyzed for the different materials combinations and fiber fractions. For the validation of numerical results, the prismatic concrete specimen filled by the curvilinear shaped cylindrical steel fibers under compression is investigated experimentally. Comparison of theoretical and experimental data is made.
Field Measurement of Natural Electromagnetic Emissions near the Active Tectonic and Mass-Movement Fractures in Caves
Authors: Trčka Tomáš , Macků Robert , Koktavý Pavel , Škarvada Pavel , Baroň Ivo , Stemberk Josef
Published: December 2016

Laboratory tests on a wide range of solid materials shoved that the electromagnetic emission (EME) signals are generated during the samples mechanical stress. EME anomalies have been observed also under natural conditions in association to fracture processes, tectonic loading, stress redistribution and crack propagation prior to earthquake or in relation to deep-seated gravitational mass movements. This paper describes a first prototype of the Emission data logger, which was specially developed for the continual EME monitoring in field conditions. Our equipment has been installed and tested in Obir Caves (Austria) at an active tectonic fault. The pilot long-term EME measurement results from this location are also presented in this paper.
Investigation of Defects at Cu(In,Ga)Se2 Flexible Solar Cells on Macroscopic and Microscopic Level and their Influence on Solar Cell Performance
Authors: Škarvada Pavel , Macků Robert , Skvarenina Lubomir
Published: December 2016

This paper investigates imperfection issues of Cu (In,Ga)Se2 thin-film solar cell structures and diagnostic methods of the CIGS solar cells. Electroluminescence and thermography are used to localize defect in macroscopic scale. Microstructures found in defective solar cell area are shown using micrographs. Focused ion beam was used to demonstrate that these structures interfere each solar cell layers. It is shown that micro sized defects (voids) behave as extra-stressed conductive channels that can degrade solar cells in module.
Study of Initial Stages of Fatigue Process in Selective Laser Melting Material Using Acoustic Emission Method
Authors: Kratochvilova Vendula , Zemanova Lucie , Vlasic František , Mazal Pavel
Published: December 2016

This paper deals with the evaluation of the fatigue tests and subsequent analyses of damage processes in selective laser melting (SLM) materials under bending loading. Compared to conventional production technologies (casting, forming and machining), SLM offers a wide range of benefits, e.g. production with no need for expensive molds, very low material waste and the possibility to create complex geometric shapes. The acoustic emission method was used to fully understand the processes which appear in the stages preceding the crack initiation. The fatigue tests at room temperature were conducted on standard wrought 2618A aluminium alloy as a representative testing material and the same material created by SLM. The main aim of the study was to compare the acoustic emission signal during fatigue loading at different manufacturing parameters of SLM material and to analyze in detail the signal changes in initial stages of fatigue process.
The results show the high sensitivity of the acoustic emission technique to the fracture behaviour of SLM material and transition from the stage of surface relief evolution to the stage of crack nucleation and propagation. After completion of dynamic mechanical tests, a detailed fractographic analysis was conducted to assess material response to mechanical loading. Attention was focused on determining the predominant failure mechanisms and the influence of defects or inhomogeneities such as pores, cavities, etc. resulting from the production of materials using SLM method.
Evaluation of Acoustic Emission Events Generated at Three Point Bending of Different Concrete Specimens by Spectral Analysis
Authors: Pazdera Lubos , Topolář Libor , Daněk Petr , Smutny Jaroslav , Mikulášek Karel
Published: December 2016

The paper aims to the determine of the mechanical properties of the concrete specimens at three-point bending test by application of the Acoustic Emission Method. Recorded acoustic emission events generated during three-point loading have been chosen. Some frequency and joint time-frequency methods are applied to these records.
Time series as acoustic emission events may be analyzed in the time, frequency, and/or time-frequency domains.
The selection is based on the type of the signal in question, on the type of analysis to be used or the result achieved. In many applications, direct evaluation of the time-amplitude representation is neither easy nor advantageous. The individual mixtures were different in cement dosage and water-cement ratio based on how much the amount of cement was increased while maintaining consistency S2 according to EN 206.
An Initial Investigation on the Potential Applicability of Non-Destructive Methods to Assessing Joint Condition in Prefabricated Structures
Authors: Manychova Monika , Fuciman Ondřej , Pazdera Lubos
Published: December 2016

Prefabricated structures have brought quite a new quality into the design of building construction method, which in turn required deeper theoretical knowledge, replacing empirical approaches by theory, replacing idealized and often simplified models of structure behaviour by accurate material physical models and load models. High rigidity of prefabricated concrete structures and the resulting stress states, which are mainly due to the volume change effects (temperature, humidity), effects of the foundation base shape variations etc., are among the most frequent causes of failures, particularly of joints of building elements featuring insufficient yield and bearing capacity. Investigation of all prefabricated building types shows progressing joint armature corrosion, considerable impairment of welds, which should secure the positional reliability of façade slabs.The paper presents some results of our experimental study of the application potential of the impact-echo method to the non-destructive assessment of the present joint condition in prefabricated structures.
Short-Term Stable Crack Propagation through Polyolefin Single- and Bilayered Structures - Influence of Welding, Composition and Direction of Crack Propagation
Authors: Lach Ralf , Krolopp Tobias , Hutař Pavel , Nezbedova Eva , Grellmann Wolfgang
Published: December 2016

The overall stable crack initiation and propagation behaviour of specimens cut from plastic pipes that were composed of different polyolefin materials were investigated using concepts of elastic–plastic fracture mechanics including the crack propagation kinetics. The effect of specimen shape, orientation, welding, lading rate, composition/microstructure and direction of crack propagation on the crack resistance (R) behaviour of these materials has been thereby assessed.
Aging of the β21S Titanium Alloy
Authors: Vigié Héloise , Soula Aurélie , Viguier Bernard
Published: December 2016

Ti-β21S is a β-metastable titanium alloy, currently used in industries such as aeronautics, because of its cold formability, good mechanical properties at elevated temperature, low density and its strong resistance to oxidation. This alloy is hardened by an α-phase precipitation in the β-matrix. The purpose of the present research is to establish the effect of aging on the microstructure and mechanical properties of Ti-β21S. Different thermal aging tests have been carried out at 600°C and at 650°C for 500 hours in laboratory air. The evolution of the microstructure has been reported after each thermal treatment and associated with room temperature tensile tests results.
The Development of Strength and Microstructure of the Resin Mortar
Authors: Gruszczyński Maciej , Lenart Małgorzata
Published: December 2016

Intensive development of building chemistry enabled the effective development of building materials based on resins. Polymer concrete is an example of such material. Its advantages are high mechanical strength, particularly flexural and tensile ones, and good resistance to vibrations in comparison with ordinary concrete. Furthermore, the high water resistance and resistance to aggressive media cause that resin-based mortars or concretes, despite their high price, are building materials widely used. The article presents a study on the strength development of selected resin mortars, prepared from a two-component epoxy resin and different proportions of quartz sand. The development of mortar compressive and flexural strength at 1, 3, 7 and 28 days of hardening was analyzed. The mortar microstructure of tested material was also investigated by the means of the Zeiss Nova scanning microscope.
Analysis of Resin Mortar Shrinkage and Adhesion
Authors: Lenart Małgorzata , Gruszczyński Maciej
Published: December 2016

Resin mortars and concretes have high water resistance and very good resistance to aggressive environment. For this reason, they are often used as repair or waterproof layers e.g. in tanks for liquids. Materials used in this regard should be characterized by relatively low shrinkage and high adhesion to a substrate.The research program was carried out on selected resin mortars composed of quartz sand and a two-component epoxy resin of high viscosity and adhesion to substrate. The shrinkage development of tested resin mortars was analyzed in the paper. The tests were conducted in automatic measurement system, so-called gutters. In this device the whole volume changes (both expansion and shrinkage) can be measured starting from the moment when material is placed into gutter. The resin mortar adhesion to a concrete substrate was also tested and discussed in the paper.
A Study on the Influence of Concrete Type and Strength on the Relationship between Initial and Stabilized Secant Moduli of Elasticity
Authors: Domagała Lucyna
Published: December 2016

The paper focuses on the influence of concrete type and strength on the relationship between initial and stabilized secant moduli of elasticity. These moduli, as well as compressive strength and density, were tested for four structural concrete series: two lightweight aggregate and two normal-weight ones. The carried out research showed that in each case the value of initial secant modulus of elasticity was lower than the stabilised one and the ratio of these two moduli is strongly dependent on concrete material homogeneity.
Microstructure Analysis and Mechanical Properties of Low Alloy High Strength Quenched and Partitioned Steel
Authors: Forouzan Farnoosh , Gunasekaran Suresh , Hedayati Ali , Vuorinen Esa , Mücklich Frank
Published: December 2016

Gleeble study of the quenching and partitioning (Q&P) process has been performed on Domex 960 steel (Fe, 0.08 %C, 1.79 %Mn, 0.23 %Si, 0.184 %Ti, and 0.038 %Al). The effect of different Q&P conditions on microstructure and mechanical properties were investigated. The aim of the process is to produce a fine grained microstructure for better ductility and controlled amounts of different micro-constituents to increase the strength and toughness simultaneously. Three different quenching temperatures, three partitioning temperatures and three partitioning times have been selected to process the 27 specimens by Gleeble® 1500. The specimens were characterized by means of OM, SEM, XRD, hardness and impact tests. It was found that, fine lath martensite with retained austenite is achievable without high amount of Si or Al in the composition although lack of these elements may cause the formation of carbides and decrease the available amount of carbon for partitioning into the austenite. The hardness increases as the quenching temperature is decreased, however, at highest partitioning temperature (640◦C) the hardness increases sharply due to extensive precipitate formation.
An Abrasion Damage of Fly Ash Concretes Previously Subjected to Scaling
Authors: Nowak-Michta Aneta
Published: December 2016

Effect of quantity and quality of fly ash and compressive strength of concretes with their addition on abrasion resistance previously subjected to scaling is analyzed in the paper. The abrasion resistance was measured in Böhme test according to EN 1338: 2005. The cement was replaced with 20, 35, and 50% of Class F siliceous fly ash in three categories of losses on ignition A, B and C by mass. The water-binder ratio, the air-entrainment and the workability of mixtures were maintained constant at 0.38, 4,5% and 150 mm respectively.Prior scaling causes a decrease in abrasion resistance of fly ash concretes. In addition, both quantitative and qualitative fly ash parameters and compressive strength have an influence on abrasion damage.
Combination of Experiments and Continuum Damage Mechanics Approach for Prediction of Creep Fracture in an Advanced 9%Cr Steel
Authors: Sklenička Václav , Kuchařová Květa , Kvapilová Marie , Král Petr , Dvořák Jiří
Published: December 2016

As candidate materials for high-temperature components, most attention has been paid to improving tempered martensitic creep-resistant 9-12%Cr steels. In this work, creep damage and fracture behaviour of an advanced W-modified P92 steel (ASTM Grade P92) was investigated at 600 and 650°C. Tensile creep tests were followed by fractographic analysis of crept and broken specimens. Besides experimental investigations, the creep damage tolerance parameter λ has been used to assess the creep fracture mode. In accordance with experiments the values of λ indicate variety in the fracture mode and provide some evidence on accelerated degradation of the creep strength. The SEM investigations of creep fracture surface revealed substantial changes in microfractographic features of creep fracture. At high applied stress level, the fracture was frequently transgranular due to local loss of a stability of plastic deformation. The fracture ductility drops with decreasing applied stress, demonstrating ductile dimple (transgranular) to brittle (intergranular cavitation) transition of the fracture mode. It was suggested that both the creep deformation and fracture processes are controlled by the same processes and the rate controlling mechanism is most probably climb of intergranular mobile dislocations.
Influence of Extension of Load Spectrum on Estimation of Residual Fatigue Lifetime of Railway Axle
Authors: Pokorný Pavel , Hutař Pavel , Náhlík Luboš
Published: December 2016

Railway axles are subjected to cyclic amplitude loading which can lead to fatigue failure. For safe operation of railway axles a damage tolerance approach taking into account a possible defect in railway axle is often required. Because of different operation regimes of trains (fast/slow ride, ride on straight track, on curved track, over switches etc.) the load amplitude of axle is not constant. The variability of load is defined by a load spectrum, which is determined experimentally by measuring of load in service conditions. Even though the load spectrum is measured on several hundreds or thousands of operation kilometres, the railway axles are in operation much longer time (often tens of years). Therefore, some load amplitudes higher than ones measured in the test can occur during a long-term axle service. The contribution presented deals with the effect of extension of load spectrum by rare high load amplitudes, which can occur during long-term operation, on residual fatigue lifetime of railway axles.
Laboratory Controlled Rolling of Microalloyed Steel for Production of Seamless Tubes
Authors: Kawulok Petr , Jurča Radek , Schindler Ivo , Rusz Stanislav , Turoň Rostislav , Opěla Petr , Kawulok Rostislav
Published: December 2016

Using the laboratory rolling mill with smooth rolls, piercing, as well as rolling in a pilger mill of the seamless tubes with diameter 273 mm from the HSLA steel microalloyed with vanadium steel was simulated. Influence of the wall thickness (6.3 – 40 mm) and finish rolling temperature on the final structural and mechanical properties was investigated. Necessary temperatures of the phase transformations in the course of cooling were determined by dilatometric tests. Based on the dilatometry results, finish rolling temperatures were reduced. Lower rolling temperatures yielded in a relative grain refinement. Effect of the finish rolling temperature did not have any marked impact on the tensile tests results. Strength properties decreased only slightly with the increasing wall thickness and the plastic properties were not influenced significantly by this parameter. The positive effect of the reduced finishing temperature appeared markedly in the results of impact tests performed at room temperature only. Notch toughness was increased by approx. 25 % in the case of the wall thickness of not less than 20 mm.
Alkali Activated Binders Based Concrete Specimens: Length Change and Fracture Tests
Authors: Bílek Jr. Vlastimil , Šimonová Hana , Havlíková Ivana , Topolář Libor , Kucharczyková Barbara , Keršner Zbyněk
Published: December 2016

The aim of this paper is to quantify mechanical fracture and length change parameters of the two types of concrete with alkali activated binder. The six beam specimens (75 × 75 × 295 mm) were made from each mixture. After demolding specimens were placed in air storage for 28 days. During this period length change (shrinkage) were recorded in accordance with ASTM C490 (2011). After that the three-point bending test was performed on these specimens with initial stress concentrator at the age of 28 days to obtain the mechanical fracture parameters. Records of fracture tests in form load versus deflection (F–d) diagrams were evaluated using effective crack model and work of fracture method.
Mechanical Properties and Microstructures of Narrow Gap Orbital Welded P91 Steel
Authors: Junek Michal , Svobodová Marie , Janovec Jiří , Horváth Jakub
Published: December 2016

This article deals with the results of mechanical testing and structural analysis of sections of narrow gap orbital welded P91 steel on tube OD 355.6 x 40 mm. The evaluation of mechanical properties was based on tensile test at room temperature on mini-tensile specimens and on measurement of modulus of elasticity. Weld was cut longitudinally into 9 narrow slices by using waterjet. From these slices 108 flat mini-tensile specimens (dimensions of gauge is 2 x 2 mm) were prepared. In experimental part microstructure evaluation and documentation of fracture surface of each mini-tensile specimen were carried out. The aim of these experiments was to assess the mechanical properties of the individual sections of the weld (base metal, heat affected zone and weld metal). These data can be used for new approaches of FEM modelling of welds considering heat affected zone like a combination of different materials with different mechanical properties, which connect the thermally unaffected base metal and weld metal.
Cross-Sectional Deformation in Multi-Walled Carbon Nanotubes under Hydrostatic Pressure
Authors: Sato Motohiro , Yachi Yu , Koike Ikuyo , Shima Hiroyuki , Umeno Yoshitaka
Published: December 2016

This contribution provides simulated results of cross-sectional deformations observed in carbon nanotubes under high pressure. Molecular dynamics (MD) simulations were performed to explore radial buckling characteristics of multi-walled carbon nanotubes, and confirmed a variety of large-amplitude deformation modes. The energetically stable deformation mode turned out to be strongly dependent on the diameter of the innermost tube and the number of concentric walls. Critical buckling pressure obtained by MD simulations was compared with that estimated from a continuum elastic approximation, by which the validity of the continuum approximation was assessed.
Development of Neural-Network Interatomic Potentials for Structural Materials
Authors: Kobayashi Ryo , Tamura Tomoyuki , Takeuchi Ichiro , Ogata Shuji
Published: December 2016

The validity of the molecular dynamics (MD) simulation is highly dependent on the accuracy or reproducibility of interatomic potentials used in the MD simulation. The neural-network (NN) interatomic potential is one of promising interatomic potentials based on machine-learning method. However, there are some parameters that should be determined heuristically before making the NN potential, such as the shape and number of basis functions. We have developed a new approach to select only relevant basis functions from a lot of candidates systematically and less heuristically without loosing the accuracy of the potential. The present NN potential for Si system shows very good agreements with the results obtained using ab-initio calculations.
Comparison of Classical Molecular Dynamics and Ab Initio Modeling of Discrete Breathers in Graphene
Authors: Lobzenko Ivan P. , Chechin George M. , Dmitriev Sergey V.
Published: December 2016

A density functional theory based method was used to model dynamics of high frequency delocalized normal mode and discrete breathers in graphene at T = 0 K. For the normal mode the comparison of results was made with modeling by means of classical molecular dynamics. Discrete breathers have been found only in presence of uniaxial strain applied in “zigzag” direction. The oscillations of breather core atoms appeared to be polarized along “arm-chair” direction. In the case of “arm-chair” uniaxial strain there were no breathers found. The frequency on the amplitude dependency of DBs in graphene corresponds to the soft nonlinearity type that is due to the soft nonlinearity type of the high frequency normal mode on which breather is constructed.
Shape of Small Prismatic Dislocation Loops in Tungsten and Iron
Authors: Fikar Jan , Gröger Roman
Published: December 2016

Small prismatic dislocation loops in BCC metals have Burgers vectors either ½<111> or <100> and are usually close to circular shape. In atomistic simulations constructing prismatic dislocation loops of different shapes is straightforward, however, it is difficult to compare their formation energies, since loops of different shapes or different Burgers vectors do not necessarily have exactly the same size. Here we develop a general method to correctly compare loops of similar size but different shapes and the Burgers vectors. This method is combined with molecular statics simulations to identify the most energetically favorable shapes of prismatic dislocation loops in elastically isotropic tungsten and anisotropic α-iron.
Tolerogenic Dendritic Cells from Poorly Compensated Type 1 Diabetes Patients Have Decreased Ability To Induce Stable Antigen-Specific T Cell Hyporesponsiveness and Generation of Suppressive Regulatory T Cells
Authors: Dáňová Klára , Grohová Anna , Strnadová Pavla , Funda David P. , Šumník Zdeněk , Lebl Jan , Cinek Ondřej , Průhová Štěpánka , Koloušková Stanislava , Obermannová Barbora , Petruželková Lenka , Šedivá Anna , Fundová Petra , Buschard Karsten , Špíšek Radek , Palová-Jelínková Lenka
Published: December 2016

Tolerogenic dendritic cells (tolDCs) may offer an interesting intervention strategy to re-establish Ag-specific tolerance in autoimmune diseases, including type 1 diabetes (T1D). T1D results from selective destruction of insulin-producing β cells leading to hyperglycemia that, in turn, specifically affects a patient’s immune system. In this study, we prepared monocyte-derived tolDCs modulated by dexamethasone and vitamin D2 from 31 T1D patients with optimal glycemic control and 60 T1D patients with suboptimal glycemic control and assessed their tolerogenic properties in correlation with metabolic state of patients. tolDCs differentiated from both groups of patients acquired a regulatory phenotype and an anti-inflammatory profile. Interestingly, tolDCs from well-controlled patients expressed higher levels of inhibitory molecules IL-T3 and PD-L1. Additionally, glutamic acid decarboxylase (GAD)65–loaded tolDCs from well-controlled patients decreased significantly primary Th1/Th17 responses, induced stable GAD65-specific T cell hyporesponsiveness, and suppressed markedly control DC-induced GAD65-specific T cell activation compared with poorly controlled patients. The ability of tolDCs from poorly controlled patients to induce durable GAD65-specific T cell hyporesponsiveness was reversed once the control of glycemia improved. In both groups of patients, tolDCs were able to induce regulatory T cells from autologous naive CD4+ T cells. However, regulatory T cells from well-controlled patients had better suppressive abilities. The functionality of tolDCs was confirmed in the adoptive transfer model of NOD-SCID mice where tolDCs delayed diabetes onset. These results suggest that metabolic control of T1D affects the functional characteristics of tolDCs and subsequent effector T cell responses. Metabolic control may be relevant for refining inclusion criteria of clinical trials in the settings of T1D.
γδ T Cells Coexpressing Gut Homing α4β7 and αE Integrins Define a Novel Subset Promoting Intestinal Inflammation
Authors: Do Jeong-su , Kim Sohee , Keslar Karen , Jang Eunjung , Huang Emina , Fairchild Robert L. , Pizarro Theresa T. , Min Booki
Published: December 2016

γδ T lymphocytes, dominant T cell subsets in the intestine, mediate both regulatory and pathogenic roles, yet the mechanisms underlying such opposing effects remain unclear. In this study, we identified a unique γδ T cell subset that coexpresses high levels of gut-homing integrins, CD103 and α4β7. They were exclusively found in the mesenteric lymph node after T cell–mediated colitis induction, and their appearance preceded the inflammation. Adoptive transfer of the CD103+α4β7high subsets enhanced Th1/Th17 T cell generation and accumulation in the intestine, and the disease severity. The level of generation correlated with the disease severity. Moreover, these cells were also found to be elevated in a spontaneous mouse model of ileitis. Based on the procolitogenic function, we referred to this subset as “inflammatory” γδ T cells. Targeting inflammatory γδ T cells may open a novel strategy to treat inflammatory diseases where γδ T cells play a pathogenic role including inflammatory bowel disease.
Combined Single-Cell Measurement of Cytokine mRNA and Protein Identifies T Cells with Persistent Effector Function
Authors: Nicolet Benoit P. , Guislain Aurelie , Wolkers Monika C.
Published: December 2016

Effective T cell responses entail the coproduction of IFN-γ, TNF-α, and IL-2. Cytokine production is determined by transcriptional and posttranscriptional events. However, increased transcript levels do not always translate into protein production, and therefore simultaneous transcripts and protein measurement are essential for the appropriate analysis of T cell responses. In this study, we optimized flow cytometry–based fluorescence in situ hybridization (Flow-FISH) for IFN-γ to multicolor flow cytometry that allows for single-cell measurement of mRNA and protein levels. This high-throughput analysis detected Ag-specific human T cells of low frequency. We also employed Flow-FISH for single-tube analysis of IFN-γ transcript and protein profile to simultaneously study the responsiveness of different T cell subsets, that is, naive, effector, and memory T cells. Importantly, the simultaneous transcript and protein analysis of IFN-γ and of TNF-α and IL-2 revealed that T cell responses consist of two types: one subtype loses mRNA expression during activation, whereas the other maintains high transcript levels throughout stimulation. High cytokine transcript levels correlated with increased protein production. Intriguingly, this mRNAhi-expressing T cell population also produced higher levels of other cytokines, indicating that Flow-FISH helps identify the best cytokine producers during T cell activation. We conclude that Flow-FISH is a rapid, sensitive, and cost-effective method to determine the quality of T cell responses induced by, for instance, T cell vaccines.
The Common R71H-G230A-R293Q Human TMEM173 Is a Null Allele
Authors: Patel Seema , Blaauboer Steven M. , Tucker Heidi R. , Mansouri Samira , Ruiz-Moreno Juan Sebastian , Hamann Lutz , Schumann Ralf R. , Opitz Bastian , Jin Lei
Published: December 2016

TMEM173 encodes MPYS/STING and is an innate immune sensor for cyclic dinucleotides (CDNs) playing a critical role in infection, inflammation, and cancer. The R71H-G230A-R293Q (HAQ) of TMEM173 is the second most common human TMEM173 allele. In this study, using data from the 1000 Genomes Project we found that homozygous HAQ individuals account for ∼16.1% of East Asians and ∼2.8% of Europeans whereas Africans have no homozygous HAQ individuals. Using B cells from homozygous HAQ carriers, we found, surprisingly, that HAQ/HAQ carriers express extremely low MPYS protein and have a decreased TMEM173 transcript. Consequently, the HAQ/HAQ B cells do not respond to CDNs. We subsequently generated an HAQ knock-in mouse expressing a mouse equivalent of the HAQ allele (mHAQ). The mHAQ mouse has decreased MPYS protein in B cells, T cells, Ly6Chi monocytes, bone marrow–derived dendritic cells, and lung tissue. The mHAQ mouse also does not respond to CDNs in vitro and in vivo. Lastly, Pneumovax 23, with an efficacy that depends on TMEM173, is less effective in mHAQ mice than in wild type mice. We conclude that HAQ is a null TMEM173 allele. Our findings have a significant impact on research related to MPYS-mediated human diseases and medicine.
Effectiveness of Occupational Therapy Interventions for Adults With Rheumatoid Arthritis: A Systematic Review
Authors: Siegel Patricia , Tencza Melissa , Apodaca Beverly , Poole Janet L.
Published: December 2016

OBJECTIVE. We reviewed the efficacy of occupational therapy–related interventions for adults with rheumatoid arthritis.

METHOD. We examined 51 Level I studies (19 physical activity, 32 psychoeducational) published 2000–2014 and identified from five databases. Interventions that focused solely on the upper or lower extremities were not included.

RESULTS. Findings related to key outcomes (activities of daily living, ability, pain, fatigue, depression, self-efficacy, disease symptoms) are presented. Strong evidence supports the use of aerobic exercise, resistive exercise, and aquatic therapy. Mixed to limited evidence supports dynamic exercise, Tai Chi, and yoga. Among the psychoeducation interventions, strong evidence supports the use of patient education, self-management, cognitive–behavioral approaches, multidisciplinary approaches, and joint protection, and limited or mixed evidence supports the use of assistive technology and emotional disclosure.

CONCLUSION. The evidence supports interventions within the scope of occupational therapy practice for rheumatoid arthritis, but few interventions were occupation based.
Occupational Therapy and Management of Multiple Chronic Conditions in the Context of Health Care Reform
Authors: Leland Natalie E. , Fogelberg Donald J. , Halle Ashley D. , Mroz Tracy M.
Published: December 2016

One in four individuals living in the United States has multiple chronic conditions (MCCs), and the already high prevalence of MCCs continues to grow. This population has high rates of health care utilization yet poor outcomes, leading to elevated concerns about fragmented, low-quality care provided within the current health care system. Several national initiatives endeavor to improve care for the population with MCCs, and occupational therapy is uniquely positioned to contribute to these efforts for more efficient, effective, client-centered management of care. By integrating findings from the literature with current policy and practice, we aim to highlight the potential role for occupational therapy in managing MCCs within the evolving health care system.
Occupational Therapy Interventions for Adolescents With Autism Spectrum Disorder
Authors: Tomchek Scott , Koenig Kristie Patten , Arbesman Marian , Lieberman Deborah
Published: December 2016

Evidence Connection articles provide a clinical application of systematic reviews developed in conjunction with the American Occupational Therapy Association’s (AOTA’s) Evidence-Based Practice Project. In this Evidence Connection article, we describe a case report of an adolescent with autism spectrum disorder. The occupational therapy assessment and treatment processes for school, home, community, and transition settings are described. Findings from the systematic reviews on this topic were published in the September/October 2015 issue of the American Journal of Occupational Therapy and in AOTA’s Occupational Therapy Practice Guidelines for Individuals With Autism Spectrum Disorder. Each article in this series summarizes the evidence from the published reviews on a given topic and presents an application of the evidence to a related clinical case. Evidence Connection articles illustrate how the research evidence from the reviews can be used to inform and guide clinical decision making.
AJOT Celebrates AOTA’s Centennial
Authors: Richards Lorie Gage
Published: December 2016

Each issue of the 2017 volume of the American Journal of Occupational Therapy will feature a special Centennial Topics section containing two to four articles related to a specific theme. The goal is to acknowledge occupational therapy’s history while focusing on the future of the profession. The Centennial Topics section is intended to help occupational therapy professionals in all aspects of the profession take stock of how far the profession has come and to spark interest in the many exciting paths for the future development of the field.
Factors influencing e-Procurement adoption in the Nigerian building industry
Authors: Ibem Eziyi Offia , Aduwo Egidario Bridget , Tunji-Olayeni Patience , Ayo-Vaughan Emmanuel Adekunle , Uwakonye Uwakonye Obioha
Published: December 2016

Against the backdrop of increasing adoption of e-Procurement in supply chain management, there is a need for adequate knowledge of the factors that influence the decision by organizations in the building industry to use e-Procurement. This study aims to fill the knowledge gap through investigating the factors influencing e-Procurement adoption based on the data sourced in a questionnaire survey involving 213 organizations in the building industry. The survey was conducted between June and November 2015 in Nigeria. Descriptive statistics, factor and categorical regression analyses were used to analyze the data. The results show that the three most important factors influencing the adoption of e-Procurement amongst the participants, in order of importance, were: the benefits of e-Procurement in enhancing efficiency in project delivery; eliminating geographic barriers and effective communication among project team members. The 29 factors were investigated in seven different dimensions - the benefits of e-Procurement use; level of awareness on e-Procurement in construction; and the availability and cost of e-Procurement applications emerged as the three most significant predictors of e-Procurement adoption in the survey. The study concludes by identifying strategies that should be engaged in increasing the uptake and maximizing the benefits of e-Procurement in the Nigerian building industry.
Predicting the academic success of architecture students by pre-enrolment requirement: using machine-learning techniques
Authors: Aluko Ralph Olusola , Adenuga Olumide Afolarin , Kukoyi Patricia Omega , Soyingbe Aliu Adebayo , Oyedeji Joseph Oyewale
Published: December 2016

In recent years, there has been an increase in the number of applicants seeking admission into architecture programmes. As expected, prior academic performance (also referred to as pre-enrolment requirement) is a major factor considered during the process of selecting applicants. In the present study, machine learning models were used to predict academic success of architecture students based on information provided in prior academic performance. Two modeling techniques, namely K-nearest neighbour (k-NN) and linear discriminant analysis were applied in the study. It was found that K-nearest neighbour (k-NN) outperforms the linear discriminant analysis model in terms of accuracy. In addition, grades obtained in mathematics (at ordinary level examinations) had a significant impact on the academic success of undergraduate architecture students. This paper makes a modest contribution to the ongoing discussion on the relationship between prior academic performance and academic success of undergraduate students by evaluating this proposition. One of the issues that emerges from these findings is that prior academic performance can be used as a predictor of academic success in undergraduate architecture programmes. Overall, the developed k-NN model can serve as a valuable tool during the process of selecting new intakes into undergraduate architecture programmes in Nigeria.
The Dereliction Tourist: Ethical Issues of Conducting Research in Areas of Industrial Ruination
Authors: Mah Alice
Published: December 2016

Dereliction tourism is the act of seeking out abandoned industrial sites as sites of aesthetic pleasure, leisure or adventure. Drawing on research in areas of industrial ruination in Russia, the UK and North America, this article examines the role of the ‘dereliction tourist’ as a way of critically reflecting on the ethics of ‘outsider’ research. Ethical problems are associated with both dereliction tourism and ethnographic research in areas of industrial decline, including voyeurism, romanticization, and the reproduction of negative stereotypes about marginal people and places. However, both dereliction tourism and ethnographic research also share more positive ethical possibilities through offering alternative ways of imagining places and raising social justice awareness of issues related to deprivation and blight. Through considering the ambivalent figure of the dereliction tourist in relation to ethnography, this article advances a way of being in the research field through intrinsic ethical reflection and practice.
Music, Knowledge and the Sociology of Sound
Authors: Hudson Martyn
Published: December 2016

The sociology of music has often concentrated less on analysing and understanding the specificity and meanings of musical material culture as both an object and a process and more about ransacking music for insights into wider social relations like class, race and gender. The social constitution of music and the musical constitution of the social deserve a more sustained attempt at explicating relations and musical forms. This paper looks at the literature on what is specifically sociological about music and why music is important for sociology but also begins to problematize the relationship between social science and material culture by moving beyond popular music studies and the study of music more generally to examine the sociology of sound and sound art. We argue that this raises difficulties for the whole concept of the social as part of a human science and that new sound studies have to have a more nuanced and critical understanding of sociological epistemologies and the objects and processes they seek to explicate at the same time as understanding the material formation of music. Questions of knowledge and meaning are embedded in music and the paper concludes by thinking about knowledge and the materiality of music as knowledge.
‘Most Challenging? To Fit in with People While Remaining Myself.’ Social Integration of Second Generation Turks within the Dutch Higher Education Setting
Authors: Pásztor Adél
Published: December 2016

By focusing on second generation Turks in the Netherlands the paper aims to study the role of friends and peers in terms of ‘fitting in’ to a higher education setting. In-depth interviews with Turkish higher education students and recent graduates confirm the existence of certain ‘coping strategies’ which ethnic minority students employ in order to integrate into the social fabric of their university or college. Social integration is usually achieved through joining existing networks of ethnic minority students, creating new networks, or simply, keeping ‘old’ high school friends throughout university. However, in some cases students are willing to change their course, institution or type of study in order to improve their experience, all pointing to the high importance of social integration for many.
On Being a Punk and a Scholar: A Reflexive Account of Researching a Punk Scene in Russia
Authors: Gololobov Ivan
Published: December 2016

Ethnographic studies of youth subcultures, scenes and urban tribes often rely on insiders’ accounts, where researchers investigate a social environment of which they are presently or formerly members. This approach raises important questions about the positionality of the researcher, and the reflexivity, epistemology and ethics of an ethnographic investigation, as different roles and engagement with the field, as well as the very identity of the ‘field’ itself, no longer fit into the methodological framework of traditional ethnography. This article explores the difficulties that arise during ethnographic research on one's own social world. I was actively involved in the Russian punk scene before pursuing my academic career in England, and in the framework of a research project on post-socialist punk at the University of Warwick, I went back to study this milieu as a ‘field’ in two different sites in 2009 and in 2010. The article shows the complexity of researching one's own subculture and demonstrates that active discentring of the ‘knowing authority’ in studying one's own ‘tribe’ necessarily involves a transformation of its main research paradigms, where epistemological and ethical issues appear to be rearranged in a new way which radically affects the methodological foundations of such an investigation.
Trust, Access and Sensitive Boundaries between ‘Public’ and ‘Private’: A Returning Insider's Experience of Research in Bulgaria
Authors: Kremakova Milena I.
Published: December 2016

The article argues that social researchers need a critical, locally situated and historically informed understanding of the categories of ‘public’ and ‘private’, in particular when carrying out research in post-socialist Eastern Europe. Drawing on an ethnographic study of the working lives of Bulgarian maritime workers, the article discusses a range of ethical fieldwork dilemmas encountered while negotiating field access, maintaining relations with gatekeepers, recruiting participants, establishing rapport, interviewing, gaining access to documentary evidence and exiting the field. The analysis focuses on the conceptual and practical boundaries between the ‘public’ and the ‘private’ and highlights the entanglement of the public and private spheres. The notion of ‘returning insider’ is developed and the implications of the returning insider's positionality are discussed in Bulgarian post-socialist context.