bluuebunny/crossref_metadata_2025 huggingface dataset:
Validation of monoclonal anti-PKC isozyme antibodies for flow cytometry analyses in human T cell subsets and expression in cord blood T cells
Authors: Perveen Khalida , Quach Alex , McPhee Andrew , Prescott Susan L. , Barry Simon C. , Hii Charles S. , Ferrante Antonio
Published: June 2019

T cells from neonates (cord blood) with a tendency to develop allergic diseases express low PKCζ levels. More extensive investigations into PKC isozyme levels in T cell subsets and changes during neonatal T cell maturation are hampered by limitations of Western blot analyses. We have undertaken to validating the specificity of commercially available antibodies marketed for flow cytometry to measure PKCα, βI, βII, δ, ε, η, θ, ζ, ι/λ and μ. Western blot analyses of human peripheral blood mononuclear cell (PBMC) lysates demonstrated that some antibodies were unsuitable for flow cytometry assays. A panel of antibodies with the desirable specificity and reliability in the flow cytometry assay were identified using both PBMC and whole blood assays. The results showed that all PKC isozymes were expressed in CD4+ and CD8+ T cells, monocytes and neutrophils. Murine lymphocytes showed similar patterns of expression. A major finding was that 35.2% and 38.5% of cord blood samples have low PKCζ (≤the 5th percentile of adult levels) in the CD4+ and CD8+ subsets, respectively, consistent with the incidence of allergy development in the population. Furthermore, these low PKCζ levels ‘normalised’ within 24 h after initiation of maturation of these cells in culture, providing a ‘window of opportunity’ for altering PKCζ levels.
Icosahedral carboranes as scaffolds for congested regioselective polyaryl compounds: the distinct distance tuning of C–C and its antipodal B–B
Authors: Kelemen Zsolt , Pepiol Ariadna , Lupu Marius , Sillanpää Reijo , Hänninen Mikko M. , Teixidor Francesc , Viñas Clara
Published: June 2019

Four-fold dense precisely defined patterns of substitution in o-carborane have been demonstrated by experimentation and computed.
Comparing the host behaviour ofN,N′-bis(9-phenyl-9-thioxanthenyl)ethylenediamine andN,N′-bis(9-phenyl-9-xanthenyl)ethylenediamine in the presence of various alkylated aromatic and aniline guests: crystal engineering considerations
Authors: Barton Benita , de Jager Lize , Hosten Eric C.
Published: June 2019

N,N′-Bis(9-phenyl-9-thioxanthenyl)ethylenediamine andN,N′-bis(9-phenyl-9-xanthenyl)ethylenediamine were assessed for their host behaviour in the presence of various alkylated aromatics and anilines.
Chalcogen bond and internal dynamics of the 2,2,4,4-tetrafluoro-1,3-dithietane⋯water complex
Authors: Jin Yan , Li Xiaolong , Gou Qian , Feng Gang , Grabow Jens-Uwe , Caminati Walther
Published: June 2019

The rotational spectrum of the 2,2,4,4-tetrafluoro-1,3-dithietane⋯water complex has been investigated by high resolution rotational spectroscopy. Inversion of the water around its C2 axis is hindered by a barrier determined to be 87.4(2) cm−1.
Solvent-induced single-crystal-to-single-crystal transformation and tunable magnetic properties of 1D azido-Cu(ii) chains with a carboxylate bridge
Authors: Liu Xiangyu , Ma Xiufang , Yang Jinhui , Luo Shuchang , Wang Zheng , Ferrando-Soria Jesús , Ma Yulong , Shi Quan , Pardo Emilio
Published: June 2019

The solvent effect leads to structural transformation and tunable magnetism of chain-like azido-copper coordination polymers.
Azamacrocycles and tertiary amines can be used to form size tuneable hollow structures or monodisperse oxide nanoparticles depending on the ‘M’ source
Authors: Tilburey Graham E. , Blundell Toby J. , Argent Stephen P. , Perry Carole C.
Published: June 2019

1,4,8,11-Tetraazacyclodecane plus (a) a silicon catecholate ion generates novel hollow tetragonal crystalline materials, and (b) tetramethoxysilane generates amorphous silica sols.
Exciton dissociation and charge separation at donor–acceptor interfaces from quantum-classical dynamics simulations
Authors: Kelly Aaron
Published: June 2019

Nonadiabatic dynamics simulations based on the quantum-classical Liouville equation are employed to study the real-time dynamics of exciton dissociation and charge separation at a model donor–acceptor interface.
Wealth from waste: blue mussels (Mylitus edulis) offer up a sustainable source of natural and synthetic nacre
Authors: Murphy Jennifer N. , Schneider Céline M. , Mailänder Lilo K. , Lepillet Quentin , Hawboldt Kelly , Kerton Francesca M.
Published: June 2019

Inner and outer layers of blue mussel shell separate easilyviaheat treatment allowing isolation of biogenic nacre and calcite.
Ring opening reactions of heterocycles with selenium and tellurium nucleophiles
Authors: Tanini Damiano , Capperucci Antonella
Published: June 2019

An overview of the preparation and synthetic potentialities of functionalized organoselenium and organotellurium compounds is presented.
Z-scheme MoS2/Bi2O3 heterojunctions: enhanced photocatalytic degradation performance and mechanistic insight
Authors: Ji Rong , Ma Changchang , Ma Wei , Liu Yang , Zhu Zhi , Yan Yongsheng
Published: June 2019

A new Z-scheme MoS2/Bi2O3 heterojunction photocatalyst was successfully prepared using a facile and practical hydrothermal method.
PdII catalyzed ligand controlled synthesis of bis(3-furanyl)methanones and methyl 3-furancarboxylates
Authors: Kusakabe Taichi , Mochida Tomoyuki , Ariyama Tomohiro , Lee Dong , Ohkubo Shin , Takahashi Keisuke , Kato Keisuke
Published: June 2019

Polysubstituted furans 2 and 3 were selectively synthesized from the same allenyl ketone substrate.
Heterogeneous Amberlyst-15-catalyzed synthesis of complex hybrid heterocycles containing [1,6]-naphthyridine under metal-free green conditions
Authors: Muthukrishnan Isravel , Vachan B. S. , Karuppasamy Muthu , Eniyaval A. , Uma Maheswari C. , Nagarajan Subbiah , Menéndez J. Carlos , Sridharan Vellaisamy
Published: June 2019

Synthesis of complex hybrid heterocycles containing [1,6]-naphthyridine under metal-free green conditions.
Correction: Ring closing metathesis (RCM) approach to the synthesis of conduramine B-2, ent-conduramine F-2, aminocyclopentitol and trihydroxyazepane
Authors: Harit Vimal Kant , Ramesh Namakkal G.
Published: June 2019

Correction for ‘Ring closing metathesis (RCM) approach to the synthesis of conduramine B-2, ent-conduramine F-2, aminocyclopentitol and trihydroxyazepane’ by Vimal Kant Harit et al., Org. Biomol. Chem., 2019, 17, 5951–5961.
Enhanced endoplasmic reticulum and mitochondrial stress in abdominal aortic aneurysm
Authors: Navas-Madroñal Miquel , Rodriguez Cristina , Kassan Modar , Fité Joan , Escudero José R. , Cañes Laia , Martínez-González José , Camacho Mercedes , Galán María
Published: June 2019

Abdominal aortic aneurysm (AAA) is a degenerative vascular disease with a complex aetiology that remains to be fully elucidated. Clinical management of AAA is limited to surgical repair, while an effective pharmacotherapy is still awaited. Endoplasmic reticulum (ER) stress and mitochondrial dysfunction have been involved in the pathogenesis of cardiovascular diseases (CVDs), although their contribution to AAA development is uncertain. Therefore, we aimed to determine their implication in AAA and investigated the profile of oxysterols in plasma, specifically 7-ketocholesterol (7-KC), as an ER stress inducer.

In the present study, we determined aortic ER stress activation in a large cohort of AAA patients compared with healthy donors. Higher gene expression of activating transcription factor (ATF) 6 (ATF6), IRE-1, X-binding protein 1 (XBP-1), C/EBP-homologous protein (CHOP), CRELD2 and suppressor/enhancer of Lin-12-like (SEL1L) and greater protein levels of active ATF6, active XBP1 and of the pro-apoptotic protein CHOP were detected in human aneurysmatic samples. This was accompanied by an exacerbated apoptosis, higher reactive oxygen species (ROS) production and by a reduction in mitochondrial biogenesis in the vascular wall of AAA. The quantification of oxysterols, performed by liquid chromatography-(atmospheric pressure chemical ionization (APCI))-mass spectrometry, showed that levels of 7-KC were significantly higher while those of 7α-hydroxycholesterol (HC), 24-HC and 27-HC were lower in AAA patients compared with healthy donors. Interestingly, the levels of 7-KC correlate with the expression of ER stress markers.

Our results evidence an induction of ER stress in the vascular wall of AAA patients associated with an increase in circulating 7-KC levels and a reduction in mitochondrial biogenesis suggesting their implication in the pathophysiology of this disease.
Behavioral Assessment of Hearing in 2- to 7-Year-Old Children: Evaluation of a Two-Interval, Observer-Based Procedure Using Conditioned Play-Based Responses
Authors: Bonino Angela Yarnell , Ramsey Michael E. , McTee Haley M. , Vance Eric A.
Published: June 2019

Purpose

It is challenging to collect reliable behavioral data from toddlers and preschoolers. Consequently, we have significant gaps in our understanding of how auditory development unfolds during this time period. One method that appears to be promising is an observer-based procedure that uses conditioned, play-based responses (
Bonino & Leibold, 2017
). In order to evaluate the quality of data obtained with this method, this study presented a suprathreshold signal to determine the number of trials 2- to 7-year-old children could complete, as well as the associated hit rate and observer confidence.

Method

Participants were 23 children (2–7 years old). Children were taught to perform a play-based motor response when they detected the 1000-Hz warble tone signal (at 30 dB SPL). An observer evaluated children's behavior using a 2-interval, 2-alternative testing paradigm. Testing was terminated after 100 trials or earlier, if signs of habituation were observed.

Results

Data were successfully collected from 22 of the 23 children. Of the 22 children, all but 1 child completed 100 trials. Overall hit rate was high (0.88–1.0;
M
= 0.94) and improved with listener age. Hit rate was stable across the test session. Strong agreement was seen between the correctness of the response and the observer's confidence in the judgment.

Conclusion

Results of this study confirm that the 2-interval, observer-based procedure described in this article is a powerful tool for measuring detection and discrimination abilities in young children. Future research will (a) evaluate coder reliability and (b) examine stability of performance across a test session when the signal intensity is manipulated.

Supplemental Material

https://doi.org/10.23641/asha.8309273
Deep activity recognition on imaging sensor data
Authors: Setiawan Feri , Yahya Bernardo Nugroho , Lee Seok‐Lyong
Published: June 2019

Inspired by the recent success of deep learning (DL) approaches in computer vision domain, this Letter proposes a framework to encode the sensor data into an image representation for the activity recognition task. The signal from sensors is encoded based on the Gramian Angular Field. The encoding technique increases the dimension of the data, captures a local temporal relationship in terms of temporal correlation between time intervals on the geometric interpretation, and can be easily applied to the pre‐trained DL architecture. The proposed framework is examined with respect to six popular sensor‐based activity recognition datasets. Using the authors’ framework, the results show that their approach outperforms most of the state‐of‐the‐art approaches.
Thermal X-ray emission identified from the millisecond pulsar PSR J1909–3744
Authors: Webb N. A. , Leahy D. , Guillot S. , Baillot d’Etivaux N. , Barret D. , Guillemot L. , Margueron J. , Miller M. C.
Published: June 2019

Context. Pulsating thermal X-ray emission from millisecond pulsars can be used to obtain constraints on the neutron star equation of state, but to date only five such sources have been identified. Of these five millisecond pulsars, only two have well-constrained neutron star masses, which improve the determination of the radius via modelling of the X-ray waveform.

Aims. We aim to find other millisecond pulsars that already have well-constrained mass and distance measurements that show pulsed thermal X-ray emission in order to obtain tight constraints on the neutron star equation of state.

Methods. The millisecond pulsar PSR J1909–3744 has an accurately determined mass, M = 1.54 ± 0.03 M⊙ (1σ error) and distance, D = 1.07 ± 0.04 kpc. We analysed XMM-Newton data of this 2.95 ms pulsar to identify the nature of the X-ray emission.

Results. We show that the X-ray emission from PSR J1909–3744 appears to be dominated by thermal emission from the polar cap. Only a single component model is required to fit the data. The black-body temperature of this emission is $ {kT}=0.26^{0.03}_{0.02} $ keV and we find a 0.2–10 keV un-absorbed flux of 1.1 × 10−14 erg cm−2 s−1 or an un-absorbed luminosity of 1.5 × 1030 erg s−1.

Conclusion. Thanks to the previously determined mass and distance constraints of the neutron star PSR J1909–3744, and its predominantly thermal emission, deep observations of this object with future X-ray facilities should provide useful constraints on the neutron star equation of state.
The use of the hollow cylinder apparatus to study stress paths relevant to railway track foundations
Authors: Mamou Anna , Powrie William , Priest Jeffrey , Clayton Chris
Published: June 2019

This paper presents and discusses results from a series of hollow cylinder tests, carried out to investigate the effects of principal stress rotation on the resilient response of soils in stress paths relevant to railway track foundations. Four sand-clay mixes, typical of the gradation of an in situ railway track foundation, were investigated. The aim of the research was to investigate the magnitudes of shear stress cycles for which the associated cyclic rotations of the principal stress direction may have a significant effect on the long-term stability of a railway track foundations.
Small-strain deformation behaviour of a clay at frozen and unfrozen states: A comparative study
Authors: Nishimura Satoshi , Okajima Shota , Wang Jinyuan , Joshi Bhakta Raj
Published: June 2019

The small-strain deformation behaviour of frozen high-plasticity clay, and the factors influencing it were investigated through parallel tests at frozen and unfrozen states. The first and second series involved temperature-controlled triaxial compression tests on unfrozen and frozen samples, respectively, with accurate strain measurement with local displacement sensors, fully calibrated for cold environment. The small-strain loading was conducted at different axial strain rates and temperatures. At pre-yield small strains in order of 0.001%, Young's modulus was independent of the strain rate, in a same manner as in unfrozen soils. The strain rate only affected the onset of small-scale yielding and the degradation of stiffness after that. The elastic strain range was greater at lower temperature, but the degree of stress-strain non-linearity seen at small strains remained on the whole similar between frozen and unfrozen states. An interesting feature of the frozen clay's stiffness, also confirmed by third test series adopting bender elements, is that it decreases when the soil is frozen from higher effective stress. A simple model was proposed to explain this feature.
Experimental Study on Relationship Between Critical State Line and Zero Creep Volume Change Zone in Engineered Silty Sand
Authors: Jung Young-Hoon , Lee Taesun , Park Ka-Hyun , Chung Choong-Ki
Published: June 2019

Volume change during creep is one of the important factors to explain various time-dependent problems such as the pile set-up effect. Park [1] and Park et al. [2] experimentally measured creep volume characteristics under various stress conditions using engineered silty sand obtained from weathered granite soil in Korea. They found that a zero-creep volume change zone (ZCVZ) exists on the e-log p' plane. If the void ratios at the beginning of the creep are above the ZCVZ on the e-log p' plane, the volume decreases during creep; if they are below the ZCVZ, the volume increases during creep. In this study, a series of simple critical state (CS) tests which can simply determine the critical state parameters in sandy soils were performed to estimate the critical state line (CSL) and compared with ZCVZ. In addition, the CSL obtained using the method proposed by Santamarina and Cho [3] was compared with those obtained by the triaxial test. The CSL for Jumunjin sand and engineered silty sand is close to ZCVZ. Therefore, the CSL can be used as a reference line to determine the volume change pattern by creep.
Effect of Inter-granular Void Ratio on Volume Compressibility and Undrained Shear Response of Base-sand and Natural Silty-sand of Kutch
Authors: Hussain Majid , Sachan Ajanta
Published: June 2019

In this article, effect of inter-granular void ratio (eg) on the volume compressibility and undrained shear strength behaviour of a natural silty-sand and base-sand is explored. Natural silty-sand sample was collected from Fatehgarh dam in Kutch region of India and the specimens prepared were subjected to isotropically consolidated undrained compression (CIUC) triaxial tests under two scenarios. In scenario one, silty-sand collected from Fatehgarh dam was used to perform CIUC triaxial tests at in-situ density. However, scenario two was based on CIUC triaxial tests on base-sand, which was extracted from Fatehgarh dam silty-sand soil by removing fines. It was ensured that the two specimens (silty-sand, base-sand) had the same void ratio (e = 0.704) but different inter-granular void ratios (eg-silty-sand = 1.156 and eg-base-sand = 0.704). Volume compressibility during isotropic consolidation phase of specimens was strongly reduced in the base-sand as compared to silty-sand. The undrained shear response of base-sand showed an increase in peak deviatoric stress by a factor of 1.8, 1.6 and 1.7 as compared to silty-sand at an initial effective confining pressure of 100 kPa, 200 kPa and 300 kPa respectively. The angle of friction mobilized at peak deviatoric stress and the work done per unit volume increased with the decrease in the inter-granular void ratio (eg), although the void ratio (e) was same.
The influence of rubber crumbs on the critical state behavior of waste mixtures
Authors: Indraratna Buddhima , Qi Yujie , Heitor Ana , Vinod Jayan S.
Published: June 2019

The practical application of waste materials such as steel furnace slag (SFS) and coal wash (CW) is becoming more prevalent in many geotechnical projects. It was found that the inclusion of rubber crumbs (RCs) from recycled tyres into mixtures of SFS and CW not only solves the problem of large stockpiles of waste tyres, it also can provide an energy-absorbing medium that will reduce track degradation. In order to investigate the influence of RC on the geotechnical properties of the granular waste matrix (SFS+CW+RC), a series of monotonic consolidated drained triaxial tests were conducted on waste mixtures. The test results reveal that the inclusion of RC significantly affects the geotechnical properties of the waste mixtures, especially their critical state behaviour. Specifically, the waste matrix can achieve a critical state with a low RC content (<20%), whereas those mixtures with higher RC contents (20-40%) cannot attain a critical state within the ultimate strain capacity that can be applied to specimens using the traditional triaxial equipment. Therefore, for the waste matrix with higher RC contents extrapolation of the measured volumetric strains had to be adopted to obtain the appropriate critical state parameters. Moreover, the influence of energy absorbing property by adding RC on the critical state behaviour has also been captured through an empirical equation.
Evaluation of the coefficient of earth pressure at rest (K0) of a saturated-unsaturated colluvium soil
Authors: Abrantes Lorena Gomes , Pereira de Campos Tácio Mauro
Published: June 2019

To predict the stress-strain behaviour of soils under loading it is relevant the knowledge of its natural stress state, expressed by the coefficient of earth pressure at rest (K0). There are correlations in theliterature for K0determination that comes from researches developed considering sedimentary soils,typically from temperate or cold regions. In dealing with residual and colluvium soils, typical of tropical regions, it is not appropriate to use these correlations, since K0is affected by factors such as degree of weathering, laterization processes and suction, among others that also affect saturated sedimentary soils. This work analysed samples of a colluvium soil from a natural slope at the Pontifical Catholic University of Rio de Janeiro. For the determination of the coefficient of earth pressure at rest of the unsaturated colluvium soil, a flexible wall equipment, with a system of suction control was used. The influence of the net stress level on the value of the coefficient of earth pressure at rest was investigated under a constant suction of 10 kPa, following a loading and unloading cycle of applied vertical stress. The coefficient of earth pressure at rest of the saturated colluvium (null suction) was also determined using a stress-path, Bishop and Wesley type, servo-controlled triaxial equipment. The obtained results are presented and discussed.
Thermally induced pore water pressure of reconstituted London clay
Authors: Chen Sihua , Zdravkovic Lidija , Carraro J. Antonio H.
Published: June 2019

Different forms of thermo-active structures have been proposed as a way of making use of the ground temperature to achieve renewable low-carbon heating and cooling in civil engineering construction. Such structures comprise piles, retaining walls or tunnel linings, and are used both as structural components and as conduits for utilising geothermal energy. In the scenario of the underground space in London, it is the thermo-active piles that have received most attention. However, little experimental evidence exists on the thermal behaviour of London clay to aid the design of thermo-active structures. This paper presents advanced laboratory testing on the reconstituted London clay to characterise the effect of temperature on its mechanical behaviour. Particular emphasis is given to thermally induced pore water pressures, as their evolution is not well understood. Tests are conducted in a temperature-controlled isotropic cell developed at Imperial College London. The emphasis of the current paper is on the temperature-based calibrations of different transducers. Soil specimens are isotropically consolidated and then subjected to undrained heating-cooling in the temperature range of 21 to 37 °C. Results obtained are compared with an existing laboratory study on another type of clay.
Monitoring hydration process and quality of sand grouted with microfine-cement using shear wave velocity and electrical conductivity measurements
Authors: Choo Hyunwook , Nam Hongyeop , Lee Changho , Lee Woojin , Burns Susan
Published: June 2019

This study aims at monitoring the grouting status such as hydration process and quality of sand grouted with microfine-cement using shear wave velocity (Vs) and electrical conductivity (EC) measurement techniques. The microfine-cement with the maximum particle size < 15 μm and the three angular sands with median particle sizes ranging from 0.47 mm to 1.01 mm were used in this study. The testing specimens were prepared at relative density ~ 70% and water to cement ratio = 1.0, 1.5, and 2.0 in a split plastic mold for the real time continuous measurements of Vs and EC, and for the unconfined compression tests at the end of curing time of 3, 7, 14, and 28 days. The results demonstrate that both unconfined compressive strength (UCS) and Vs show almost constant values after the curing period of 20-28 days; while, the variation of EC is negligible after the curing period of 10-20 days. Therefore, the shear wave velocity measurement technique can be superior to electrical conductivity measurement in terms of monitoring of hydration process of tested sands grouted with microfine-cement. However, both Vs and EC show strong linear relationship with UCS of tested materials, reflecting both non-destructive testing methods can be beneficially used for the quality evaluation of grouted materials.
Interface shear strength of polypropylene pipeline coatings and granular materials at low stress level
Authors: De Leeuw Lawrence W , Diambra Andrea , Dietz Matt S , Mylonakis George , Milewski Henry
Published: June 2019

A range of sands were tested in direct and interface shear at very low stresses to determine the interface shear strength of polypropylene pipeline coating counterfaces and to evaluate interface efficiency. Polypropylene has a wide range of applications as a coating material in the offshore environment, so quantification of interfacial strength is an important component for geotechnical design. Direct shear tests show classic peak-postpeak stress-displacement and stress-dilatancy behaviour whereas interface tests show an elastic, perfectly plastic type behaviour for both loose and dense samples with no appreciable volumetric response. Interface efficiencies generally range between 0.3 and 0.7 dependent on both grain size and stress level. Normalised roughness is used to relate the surface roughness to the grain size and shows that the greater interface strength with smaller grained sands can be explained by their greater effective roughness. The relationship between stress ratio and normalised roughness for sand-polypropylene resembles established relationships for sand-steel interfaces.
Asperities effect on polypropylene & polyester geotextile-geomembrane interface shear behaviour
Authors: Adeleke Daniel , Kalumba Denis , Oriokot Johnny
Published: June 2019

The summary of this paper is focused on the result of a study that used quantitative measures of surface texture as the basis for examining the effects of asperities on the shear characteristics of geotextile-geomembrane interfaces. About 30 large direct shear tests were conducted to evaluate the geotextile-geomembrane interface shear strength properties. The results indicated a non-linear failure envelopes and strain softening behaviour at a normal stress range of 50 – 400 kPa. For most interface tested, the polyester-geotextiles resulted in higher shear strength as compared with polypropylene-geotextiles. Also, the polyester and polypropylene geotextile interface with the high asperity geomembrane produces a similar percentage increase in friction angle at the residual state. For textured geomembranes interfaced with both geotextile, polyester geotextile exhibited relatively less time before failure. Also, asperity height has a more pronounced effect than asperity density on the residual interface shear strength. The outcome of this study would provide a recommendation and guide that can lead to an improved basis for geosynthetics selection in various engineering application.
Rational modelling of elastic soil behaviour in 3D condition
Authors: Nakai Teruo , Shahin Hossain Md. , Ishikawa Akira
Published: June 2019

A simple and rigorous formulation of elastic component of elastoplastic model for geomaterials is presented. Although linear relation between elastic volumetric strain and mean principal stress in log scale is assumed in most of the usual models, linear relation between each principal stress and the corresponding principal elastic strain in log scale is assumed. Incorporating Poisson's ratio, three principal stresses vs. three elastic principal strain relation is obtained. Also, assuming coaxially between stresses and elastic strains, this relation can be transformed to stress- elastic strain relation in general coordinate. The material parameters of the proposed model of the elastic component are the same as those of the usual models, i.e., swelling index κ and Poisson's ratio ν. This proposed model can describe typical unloading behaviour of various shear tests and constant stress ratio unloading tests reported before.
Modelling and testing of optimum soil moisture levels in the corrosion of underground pipelines
Authors: Azoor Rukshan , Deo Ravin , Kodikara Jayantha
Published: June 2019

Corrosion is one of the major factors leading to the failure of buried pipelines. Soil properties such as aeration, moisture content and level of compaction are known to cause variations in the level of corrosion of buried metallic structures. It is known that, at a particular soil moisture content, the corrosion rate reaches a maximum value. While this phenomenon is generally understood, an explanation from a soil mechanics perspective with mechanisms for soil water continuity and mass transport processes is currently lacking. This work fills this void by modelling the moisture-controlled diffusion transport and electrical conductivity in soil coupled to the electrochemical activity on the buried metal surface. Variations in the electrical conductivity and oxygen diffusion in sand at different degrees of saturation were determined experimentally. The results were used as input parameters in a finite element model. Results from the coupled finite element model were compared with experimental results from electrochemical corrosion tests. The tests were conducted on cast iron specimen buried in sand and the corrosion behaviour under various aeration regimes were studied. The presence of an optimum moisture/aeration regime, where the corrosion rate becomes a maximum was demonstrated and the mechanisms behind this phenomenological behaviour are discussed in this paper. The modelling and experimental results are expected to be useful in developing non-intrusive testing methods for underground corrosion.
A Constitutive Model for Locally Drained Shear Bands in Globally Undrained Dense Sand
Authors: Mallikarachchi Hansini , Soga Kenichi
Published: June 2019

When saturated granular materials which are dilative in nature are subjected to the undrained deformation, their strength increases due to the generation of negative excess pore pressure. This phenomenon is known as dilative hardening and can be witnessed in saturated dense sand or rocks during very fast loading. However, experimental evidence of undrained biaxial compression tests of dense sand shows a limit to this dilative hardening due to the formation of shear bands. There is no consensus in the literature about the mechanism which triggers these shear bands in the dense dilative sand under isochoric constraint. The possible theoretical reasoning is the local drainage inside the specimen under the globally undrained condition, which is challenging to be monitored experimentally. Hence, both incept of localisation and post-bifurcation of the saturated undrained dense sand demand further numerical investigation. Pathological mesh dependency hinders the ability of the finite element method to represent the localisation without advanced regularisation methods. This paper attempt to provide a macroscopic constitutive behaviour of the undrained deformation of the saturated dense sand in the presence of a locally drained shear band. Discontinuation of dilatant hardening due to partial drainage between the shear band and the adjacent material is integrated into the constitutive model without changing governing equilibrium equations. Initially, a classical bifurcation analysis is conducted to detect the inception and inclination of the shear band based on the underlying drained deformation. Then a post-bifurcation analysis is carried out assuming an embedded drained or partially drained shear band at gauss points which satisfy bifurcation criterion. The smeared shear band approach is utilised to homogenise the constitutive relationship. It is observed that the dilatant hardening in the saturated undrained dense sand is reduced considerably due to the formation of shear bands.
The effect of suction on ground surface settlement for a tunnel
Authors: Shwan Bestun
Published: June 2019

This paper addresses the physical modelling of a tunnel for saturated and unsaturated sand as well as tests in dry condition. A series of tests were conducted for a 50 mm diameter tunnel buried 25 mm into a poorly graded fine sand under different normal stresses: 0.78, 1.56, 2.34 and 3.31 kPa. Suction was controlled by means of the hanging column technique (HCT). Particle image velocimetry (PIV) was also utilised to obtain the vector displacement and compared with the results of the physical modelling. The results of the fully saturated sample showed that the sample experienced a sudden spatial collapse above and around the tunnel's crown. In addition, large displacement on top of the tunnel's crown was also observed for the fully dry case. However, the unsaturated sample did not experience any sudden collapse. This was attributed to the effect of the suction contribution on strength.
Long-Term Ultrasound Follow-Up After Pediatric Adnexal Torsion
Authors: Smorgick Noam , Nir Omer , Pekar-Zlotin Marina , Maymon Shlomit , Pansky Moty , Maymon Ron
Published: June 2019

Purpose Conservative surgical management of adnexal torsion in pre- and post-menarchal girls by de-torsion and adnexal conservation is the current standard of care. The aim of this study is to investigate the long-term outcome of adnexal torsion in this population in terms of ultrasound appearance and ovarian volume.

Methods Patients who were surgically treated for adnexal torsion and were < 18 years old at time of surgery were prospectively invited for ultrasound follow-up. The ultrasound exam included measurements of ovarian volume and grayscale appearance including identification of ovarian follicular activity.

Results 84 cases of torsion in this population were identified, and 37 of them were included in the study. Of those, the affected ovary could not be demonstrated on follow-up scan in six (16.2 %) cases. A difference of ≥ 2 cm3 in ovarian volume between the affected and non-affected ovaries was diagnosed in 12 (32.4 %) cases, but follicular activity was observed in 10 of those. Thus, possible ovarian injury (including cases of non-demonstrated ovary and volume difference of ≥ 2 cm3 between the affected and non-affected ovaries) was found in 18 (48.6 %) cases. Of the clinical and surgical parameters (including age at time of torsion, duration of pain prior to admission, cystectomy procedure and intraoperative “bluish” appearance of the ovary), only the presence of fever on admission was significantly associated with possible ovarian injury (p = 0.01).

Conclusion Long-term ultrasound follow-up of pre- and post-menarchal girls with a history of adnexal torsion may identify patients with adversely affected ovarian volume. The significance of this finding in terms of fertility is unknown.
Disinfection of Transvaginal Ultrasound Probes by Ultraviolet C – A clinical Evaluation of Automated and Manual Reprocessing Methods
Authors: Schmitz Johanna , Kossow Annelene , Oelmeier de Murcia Kathrin , Heese Sandra , Braun Janina , Möllmann Ute , Schmitz Ralf , Möllers Mareike
Published: June 2019

Purpose Since pathogens can be transmitted to patients via transvaginal ultrasound probes, it is of particular importance that cleaning and disinfection are performed adequately. This study was designed to do a qualitative comparison of a low-level disinfection technique with disinfectant-impregnated wipes and an automated disinfection technique using ultraviolet C radiation in a clinical setting.

Materials and Methods The transvaginal ultrasound probes used in two groups of 160 patients were compared in a prospective controlled study regarding the effectiveness of manual low-level disinfection (Mikrozid sensitive wipes) and automated disinfection using ultraviolet C radiation (Antigermix AS1). Microbiological samples were taken from the whole surface of the probe before and after the disinfection process.

Results Before disinfection, 98.75 % (316/320) of the samples showed bacterial contamination. After automated and manual disinfection, the contamination rates were 34.2 % (54/158, automated) and 40.5 % (64/158, disinfectant wipes) (p > 0.05). Pathogens with the potential to cause healthcare-associated infections, such as Enterococcus faecalis and Klebsiella pneumoniae, were removed completely by both techniques. Manual disinfection showed a lower contamination rate after disinfection of bacteria that usually belong to the vaginal, pharyngeal and skin flora (disinfectant wipes 10.6 %, 11/104, automated 32.5 %, 38/117) (p < 0.001).

Conclusion For the clinical routine, automated disinfection with ultraviolet C is a promising technique for transvaginal ultrasound probes because of the simple handling and time efficiency. In our study, this method was completely effective against nosocomial pathogens. However, the study didn’t show any significant difference in terms of effectiveness compared to low-level wipe disinfection.
SO2F2-Promoted Dehydration of Aldoximes: A Rapid and Simple Access to Nitriles
Authors: Zhao Yiyong , Mei Guangyao , Wang Haibo , Zhang Guofu , Ding Chengrong
Published: June 2019

A rapid, simple and mild process for the dehydration of aldoximes to give the corresponding nitriles, which utilizes SO2F2 as an efficient reagent, has been developed. A variety of (hetero)arene, alkene, alkyne and aliphatic aldoximes proceeded with high efficiency to afford nitriles in excellent to quantitative yields with great functional group compatibilities in acetonitrile under ambient conditions. Furthermore, an eco-friendly synthetic protocol to access nitriles from aldehydes with ortho-, meta- and para-nitrile groups was also described in aqueous methanol by using inorganic base Na2CO3, and a one-pot synthetic strategy to generate nitriles from aldehydes was proved to be feasible.
Copper-Catalyzed Twofold Silylmetalation of Alkynes
Authors: Yamagishi Hiroki , Shimokawa Jun , Yorimitsu Hideki
Published: June 2019

The first twofold silylmetalation across a C≡C triple bond was achieved. In the presence of a catalytic amount of copper cyanide, diarylacetylenes were converted into 1,2-dimetalated 1,2-disilyl-1,2-diarylethanes on treatment with silylpotassium species generated in situ from disilane and t-BuOK. The dimetalated species were subsequently protonated to yield a series of 1,2-disilyl-1,2-diarylethanes.
Lumbar Drain Tunneling: A Safe Two-Needle Technique
Authors: Deepti Srinivas , Ashwini Halesh , Venkatesh Keshavan
Published: June 2019

Lumbar drain catheter insertion for prolonged periods of time is necessary in a myriad of neurosurgical patients which entails its tunneling. We describe a safe and simple technique of catheter insertion and tunneling using two Tuohy needles instead of one, which prevents unintentional catheter damage during the procedure.
Application of the interacting particle system method to piecewise deterministic Markov processes used in reliability
Authors: Chraibi Hassane , Dutfoy Anne , Galtier Thomas , Garnier Josselin
Published: June 2019

Variance reduction methods are often needed for the reliability assessment of complex industrial systems, we focus on one variance reduction method in a given context, that is, the interacting particle system (IPS) method used on piecewise deterministic Markov processes (PDMPs) for reliability assessment. The PDMPs are a very large class of processes which benefit from high modeling capacities, they can model almost any Markovian phenomenon that does not include diffusion. In reliability assessment, the PDMPs modeling industrial systems generally involve low jump rates and jump kernels favoring one safe arrival, we call such model a “concentrated PDMP.” Used on such concentrated PDMPs, the IPS is inefficient and does not always provide a variance reduction. Indeed, the efficiency of the IPS method relies on simulating many different trajectories during its propagation steps, but unfortunately, concentrated PDMPs are likely to generate the same deterministic trajectories over and over. We propose an adaptation of the IPS method called IPS+M that reduces this phenomenon. The IPS+M consists in modifying the propagation steps of the IPS, by conditioning the propagation to avoid generating the same trajectories multiple times. We prove that, compared to the IPS, the IPS+M method always provides an estimator with a lower variance. We also carry out simulations on two-components systems that confirm these results.
Shift-symmetric configurations in two-dimensional cellular automata: Irreversibility, insolvability, and enumeration
Authors: Banda Peter , Caughman John , Cenek Martin , Teuscher Christof
Published: June 2019

The search for symmetry, as an unusual yet profoundly appealing phenomenon, and the origin of regular, repeating configuration patterns have long been a central focus of complexity science and physics. To better grasp and understand symmetry of configurations in decentralized toroidal architectures, we employ group-theoretic methods, which allow us to identify and enumerate these inputs, and argue about irreversible system behaviors with undesired effects on many computational problems. The concept of so-called “configuration shift-symmetry” is applied to two-dimensional cellular automata as an ideal model of computation. Regardless of the transition function, the results show the universal insolvability of crucial distributed tasks, such as leader election, pattern recognition, hashing, and encryption. By using compact enumeration formulas and bounding the number of shift-symmetric configurations for a given lattice size, we efficiently calculate the probability of a configuration being shift-symmetric for a uniform or density-uniform distribution. Further, we devise an algorithm detecting the presence of shift-symmetry in a configuration. Given the resource constraints, the enumeration and probability formulas can directly help to lower the minimal expected error and provide recommendations for system’s size and initialization. Besides cellular automata, the shift-symmetry analysis can be used to study the nonlinear behavior in various synchronous rule-based systems that include inference engines, Boolean networks, neural networks, and systolic arrays.
Spin Hall magnetoresistance in heterostructures consisting of noncrystalline paramagnetic YIG and Pt
Authors: Lammel Michaela , Schlitz Richard , Geishendorf Kevin , Makarov Denys , Kosub Tobias , Fabretti Savio , Reichlova Helena , Huebner Rene , Nielsch Kornelius , Thomas Andy , Goennenwein Sebastian T. B.
Published: June 2019

The spin Hall magnetoresistance (SMR) effect arises from spin-transfer processes across the interface between a spin Hall active metal and an insulating magnet. While the SMR response of ferrimagnetic and antiferromagnetic insulators has been studied extensively, the SMR of a paramagnetic spin ensemble is not well established. Thus, we investigate herein the magnetoresistive response of the as-deposited yttrium iron garnet/platinum thin film bilayers as a function of the orientation and the amplitude of an externally applied magnetic field. Structural and magnetic characterization shows no evidence for the crystalline order or spontaneous magnetization in the yttrium iron garnet layer. Nevertheless, we observe a clear magnetoresistance response with a dependence on the magnetic field orientation characteristic for the SMR. We propose two models for the origin of the SMR response in paramagnetic insulator/platinum heterostructures. The first model describes the SMR of an ensemble of noninteracting paramagnetic moments, while the second model describes the magnetoresistance arising by considering the total net moment. Interestingly, our experimental data are consistently described by the net moment picture, in contrast to the situation in compensated ferrimagnets or antiferromagnets.
Autonomous sensor of electromagnetic field
Authors: Jančárik V. , Hart’anský R. , Slížik J. , Mierka M. , Halgoš J. , Hallon J. , Hricko J.
Published: June 2019

The design of a uniaxial electromagnetic field sensor for measuring the antenna far field within its region of higher signal strength is described. The sensor is autonomous; i.e., it is powered by the measured field; therefore, no external power supply is necessary. After accumulating a sufficient amount of energy, the sensor runs a single measurement and sends the result through an optic fiber, or the result can be stored in nonvolatile memory. The sensor does not require any metallic cable for delivering energy; therefore, the measured field distribution is not influenced by it and the data transfer from the sensor is also not influenced by any induced noise voltage.
Parallel replica dynamics simulations of reactions in shock compressed liquid benzene
Authors: Martínez E. , Perriot R. , Kober E. M. , Bowlan P. , Powell M. , McGrane S. , Cawkwell M. J.
Published: June 2019

The study of the long-term evolution of slow chemical reactions is challenging because quantum-based reactive molecular dynamics simulation times are typically limited to hundreds of picoseconds. Here, the extended Lagrangian Born-Oppenheimer molecular dynamics formalism is used in conjunction with parallel replica dynamics to obtain an accurate tool to describe the long-term chemical dynamics of shock-compressed benzene. Langevin dynamics has been employed at different temperatures to calculate the first reaction times in liquid benzene at pressures and temperatures consistent with its unreacted Hugoniot. Our coupled engine runs for times on the order of nanoseconds (one to two orders of magnitude longer than traditional techniques) and is capable of detecting reactions that are characterized by rates significantly slower than we could study before. At lower pressures and temperatures, we mainly observe Diels-Alder metastable reactions, whereas at higher pressures and temperatures we observe stable polymerization reactions.
Geometry-dependent conductance and noise behavior of a graphene ribbon with a series of randomly spaced potential barriers
Authors: Marconcini Paolo , Macucci Massimo
Published: June 2019

We perform an envelope-function based numerical analysis of the effect of a sequence of randomly spaced potential barriers on the conductance and shot noise of an armchair graphene ribbon. The behavior is dominated by Klein tunneling and by resonant tunneling and strongly depends on the geometrical details of the device. Klein tunneling effectively filters the modes that can propagate through the device. For a large number of cascaded barriers, this gives rise to different transport regimes for metallic and semiconducting ribbons, with diverging shot noise behaviors. Resonant tunneling is instead energy selective and has quite a different effect depending on whether the barriers are identical or not. We also explore the effect of tilting the barriers with respect to the ribbon edges, observing a transition toward a diffusive transport regime and a one-third shot noise suppression. We investigate this effect, and we find that it takes place also in more traditional semiconducting materials. The results of our analysis could be instrumental for the fabrication of mode-filtering and energy-filtering graphene-based nanodevices. Moreover, our study highlights the importance of the measurement of shot noise as a probe for the nature of the transport regime.
A review and perspective on a convergence analysis of the direct simulation Monte Carlo and solution verification
Authors: Myong R. S. , Karchani A. , Ejtehadi O.
Published: June 2019

In 1963, G. A. Bird published a research note on his investigation of a rigid sphere gas reaching translational equilibrium using a Monte Carlo type method. Since then, the method has been developed into a primary workhorse to computationally solve the Boltzmann kinetic equation. As it is increasingly applied to challenging problems in the real world, verification studies of the method have become a critical issue. In this paper, we review previous studies on this challenging subject and present a perspective on a convergence analysis of the direct simulation Monte Carlo (DSMC) method and solution verification. During this process, a verification method based on the physical laws of conservation is studied in depth. In particular, a convergence history plot on all three types of computational errors—decomposition, statistical, and round-off—is presented for two benchmark problems. Finally, future research topics to maximize the full potential of the DSMC method, pioneered by the late G. A. Bird, are suggested.