bluuebunny/crossref_metadata_2025 huggingface dataset:
Sensing Characteristics of Nanostructured PANI/Ag Thin Films as H2S Gas Sensor
Authors: Akber Hassan J. , Razeg Khalid H. , Ibrahim Isam M.
Published: November 2020

Nanocomposites of polyaniline (PANI) and Silver (Ag) nanoparticles (NPs) have been successfully synthesis using hydrothermal and chemical method respectively. The nanocomposite films were deposited by spin coating technique on Si substrates and examined using XRD, FE-SEM, EDX, FT-IR techniques as well as their sensing properties were studied towards H2S gas. The XRD pattern showed a presence of crystalline nature of PANI NFs film and cubic structure of PANI/Ag films. FE-SEM images revealed that PANI film has nanofibers structure, whereas the PANI/Ag films composite revealed that Ag NPs caped with PANI nanofiber. The sensing analysis indicated that on exposure to H2S gas at low concentration 25 ppm, it was observed that the PANI/Ag films sensor composite showed high sensitivity compared with pure PANI NFs, and the maximum sensitivity (73.35%) was obtained at 200 °C with faster response/recovery times < 1 sec.
Synthesis and temperature Effect of ZnO nanoparticle seeding layer and nanorods
Authors: Rahim Hasien Ali , Salman Emad A.
Published: November 2020

Zinc oxide nanostructured with different seeding layer annealing temperature have been synthesized by drop casting technique on FTO coated glass substrate. The optimized seeding layer have employed to synthesis ZnO nanorods were growth aqueous solutions method of zinc nitrate and HML as precursors with different growth temperatures.

FESEM supported by EDS results showed significant information of ZnO topographic surface. X- Ray diffraction scan demonstrate a hexagonal wurtzite structure with c-axis orientation of the ZnO nanorods. Strong ultraviolet (UV) emission of ZnO nanorods has detected by UV visible measurement. The obtained results have analyzed optimize annealing temperature of ZnO seeding layer and suitable growth temperature of ZnO nanorods, with crystal hexagonal ZnO nanorods and homogenous distribution with 95°C growth temperature
Enhancement of the Structural and Optical Properties of (PVA-PANI) Polymer Blend By Addition of CuI Nanoparticles
Authors: Hammed Mohammed Ghazi , Hassan Ahmed Abd
Published: November 2020

PVA:PANI/CuI thin film composites have been prepared by adding (CuI) particles to the mixture of the poly vinyl alcohol (PVA) and conductive polyaniline (PANI) with various concentrations (0, 2, 4, 6, and 8% wt) using casting method technique on a glass substrate at laboratory temperature. The prepared thin film samples have lightweight, low cost, and flexible. The morphological, structural, and optical properties of these composites were examined by using Fourier transform - infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Atomic Force Microscopy (AFM).

The effects of CuI concentrations on the optical properties of the PVA:PANI thin films were studied in the region of wavelength (190-1100) nm. The results are presented the prepared thin films have high values of absorption in UV range. Increasing CuI nanoparticle concentrations lead to increases the absorbance of (PVA:PANI) blend. The optical coefficients rise while the energy gap and transmittance falls with increasing CuI nanoparticle concentrations.
Prediction of Mechanical Behaviors of the Q & P980 Steel Under Different Temperatures and Strain Rates Using Crystal Plasticity Method
Authors: Yang Hao , Wang Huamiao , Li Dayong , Peng Yinghong , Wu Peidong
Published: November 2020

The martensitic transformation in quenching and partitioning (Q&P) steels is greatly influenced by loading conditions such as environmental temperature and loading speed, and thus impacts the macroscopic mechanical properties during the deformation process. Within this work, an elastic-visco-plastic self-consistent (EVPSC) framework coupling with phase transformation model is used to simulate the stress strain responses as well as the microstructure evolution of the multi-phases Q& P980 steel under uniaxial tension process. A temperature and strain rate dependent transformation kinetics is incorporated into the model and phase transformation behaviors of the Q& P980 steel under different temperatures (25°C∼100 °C) and strain rates (0.0002s-1∼2s-1) are successfully characterized. The corresponding stress strain responses under different loading conditions are predicted and compared with the experimental data.
The Investigation of Zinc Coating Quality with Different Thickness Levels After Forming of Flat Steels
Authors: Tamer E , Yildirim O
Published: November 2020

In this study, the deformation performance of galvanized deep drawing steel is investigated depending on coating thickness and forming limit of non-alloy pure zinc coated steel. Regarding to this; 100 and 150 g/m2 Zn-coated samples are used to see the relevance with finite element analysis. To determine the deformation condition of Zn coating the samples were prepared at different elongation levels, then the samples are examined with surface views and cross-sectional analyses with scanning electron microscope to observe the amount of deformation at the onset of crack in the zinc coating cross-section. The change of zinc coating with elongation at cross-section region of the material will be investigated via microstructural analyses. It is aimed to determine the most suitable zinc coating level depending on the deep drawing amount in interstitial free (IF) steel usage. Furthermore, the performance of zinc coating will be investigated with finite element analyses with the goal of validating experimental results. Depending on the results of this study, the influence of zinc coating for a physical component will be carried out as a new study.
Development of Sheet Metal Forming Analysis Incorporating Phase-transformation Model for Hot Stamping
Authors: Uenishi K , Kubo M , Suzuki T , Okamura K
Published: November 2020

To predict the spring back after hot stamping of sheet metals, a user material routine incorporated with phase transformation effects has been developed and implemented in general-purpose commercial finite element software. The mechanical response of the metallographic structure incorporates variation of transformation plastic strain and transformation volume expansion. Additionally, the thermal response incorporates the dependencies of thermal properties and latent heat of phase transformation. The start timing of diffusive transformation was determined using Scheil’s law, and the Kolmogorov–Johnson–Mehl–Avrami equation was adopted for the progression of diffusive transformation. The Koistinen and Marburger equation was used for the progression of martensite transformation. Using the developed model, we considered the effects of phase transformation on shape fixability. We conducted experiments that focused on measuring the shape fixability of U-bend hot formed parts. In this study, we show that the spring back of the U-bend parts increases under conditions in which phase transformation occurs before formation has been completed. Furthermore, the spring back could accurately predict by using the developed model.
A Method to Incorporate Grain Boundary Strength and its Effects on Plastic Deformation in FCC Polycrystals
Authors: Muhammad W , Brahme A P , Kang J , Cyr E , Wilkinson D S , Inal K
Published: November 2020

A three-dimensional (3D) crystal plasticity finite element method (CPFEM) is developed to investigate the effect of grain boundary strength on heterogeneous strain partitioning in FCC polycrystals. The proposed method incorporates electron backscatter diffraction (EBSD) maps into finite element analyses. The numerical analysis accounts for crystallographic texture, its evolution and 3D grain morphologies. Furthermore, grain boundaries are also mapped with a special finite element framework that allows material properties to be assigned to the grain boundaries. The material parameters and the grain boundary strengths are obtained by calibration to experimental uniaxial tension curves for single and polycrystals. Numerical simulations of uniaxial tension are performed and the effects of grain boundary strength on the onset of non-uniform deformation is investigated. The predicted local strain evolution is compared with corresponding experimental results from digital image correlation (DIC) measurements of an AA5754 aluminium sheet. The results showed that an excellent agreement was reached when the grain boundary properties were set so that the hardness was five times that of the average polycrystal response.
Strain hardening under large deformation for AA5182
Authors: Zhang Chong , Wang Yue , Shang Hongchun , Wu Pengfei , Fu Lei , Lou Yanshan , Clausmeyer Till , Tekkaya A. Erman , Zhang Qi
Published: November 2020

In this study, an aluminium alloy of AA5182 is taken as the research object to study strain hardening under large plastic deformation. Tensile tests are done for four specimens, including dog-bone specimens, notched specimens, specimens with a central hole and in-plane shear specimens. Bulging tests are also conducted to measure strain hardening under balanced biaxial tension. In addition, an experimental method called in-plane torsion test is also used for shear loading. At least three experiments are completed for each type of specimens along the rolling direction (RD), diagonal direction (TD), and transverse direction (DD). The stroke of each tests is measured by a digital image correlation (DIC) system, and the load-stoke curves were obtained for the tests. Combined with an inverse engineering method, the strain hardening properties are calibrated for the alloy under different loading conditions of shear, uniaxial tension, plane strain tension, and balanced biaxial tension. The strain hardening under various loading conditions is compared and modelled by various yield functions to evaluate their performance. It is concluded that inverse engineering approach is a simple but powerful method to obtain the stress-strain curve up to large plastic deformation. It is also observed that it needs to develop yield functions to model yielding behaviour under complex loading conditions.
Evolution of a forming limit curve for non-linear strain paths induced on advanced high-strength sheet steel with its proven applicability to a complex deep-drawing process
Authors: Chongbunwatana K , Panich S , Laokor K
Published: November 2020

In this work, nonlinear forming limit curves were developed through a systematic combination of both experimental and numerical tools. FLCs derived from both intact and pre-stretched DP440 high-strength steel (HSS) sheet were involved. First of all, prepared sheet specimens were, in compliance with the Marciniak test procedure, in-plane pre-stretched in either of the following three directions, uniaxial tension, plane strain and biaxial, at varying strain levels. Afterwards, each distinguishingly pre-strained specimen was post-strained until fracture following the Nakajima test guideline. The so-called displacement function could be determined out of these experimental data. An individual nonlinear IFU-FLCs was approximated with the help of the base linear FLC, the formulated displacement function and a unique simulated strain path collectively gathered from the local fracture zone. Two yield models, Hill’48 and Yld2000- 2d, were tried during strain-path calculations to observe how different yield models would alter the paths and thus developed nonlinear FLCs. From the study, notable variation was detected. In the end, validity of such nonlinear FLCs were proven through a complex-shaped industrial stamping part. The IFU-FLC noticeably-better defined forming limits of parts experiencing nonlinear strain paths than the conventional one.
The mechanical properties of high strength Al alloy sheet under quasi-static-dynamic loading
Authors: Xia L L , Xu Y , Zhang S H , Song H W , Chen D Y
Published: November 2020

To investigate the mechanical properties of high strength Al alloy, the AA2024 was selected and conducted the uniaxial tensile tests at room temperature under different loading modes, namely pure quasi-static (QSD) loading mode, pure dynamic loading mode and quasi-static-dynamic loading mode. The mechanical properties such as yield stress (YS), ultimate tensile stress (UTS), total elongation and strain rate sensitivity were compared. The results shown that the UTS under QSD loading mode is larger than that of quasi-static and pure dynamic loading mode, and dependent on prestrain levels. However, the YS at pure dynamic loading mode is less than that of QSD loading mode at prestrain of 10% but larger than that of prestrain of 6%. In addition, the QSD loading mode would further improve the total elongation of AA2024 compared to the elongation enhancement under pure dynamic loading mode. Finally, the variation of strain rate sensitivity under different loading modes was analyzed to explain the evolution of tensile properties of AA2024.
Numerical modelling and formability of with and without heat-treated AA 6023-T6 alloy sheet with various necking/failure criteria
Authors: Ramulu Perumalla Janaki , Beri Habtamu , Rao P. Srinivasa , Sinha Devender Kumar , Gutu Moera
Published: November 2020

Sheet metal forming is a process widely used in the manufacturing industry. There are numerous sheet metal forming processes to evaluate and understand the formability. Among all formability tests, the basic formability can be formulated through tensile tests and followed with specialized tests. In the present paper, the formability of AA 6023-T6 sheet of 2mm thickness by modelling for stretching test namely limit dome height (LDH) test was performed using PAM STAMP 2G a commercial finite element software. For the simulation, input mechanical properties like yield strength (c), material strength coefficient (K), strain hardening exponent (n), plastic strain ratio (R) etc., were considered from the existing literature. For the simulation, two different conditioned sheet such as at room temperature and annealed sheet at 400°C. For all the simulations, four strain paths 100 × 200mm, 125 × 200mm, 150 × 200mm, 175 × 200mm and 200 × 200 mm were taken. Results are drawn based on the three localized necking criteria namely the effective strain rate-based criterion (ESRC – R1), major strain rate-based criterion (MSRC –R2), thickness strain rate-based criterion (TSRC – R3). Form the obtained results, forming limit diagrams are developed for the both condition of sheet metal. It is observed that, formability of AA 6023-T6 sheet in-plane condition (i.e. 100x100 mm) annealed sheet at 400°C is shown better forming whereas in bi-axial condition (i.e. 200x200 mm) got reduced compared to room temperature sheet. The same phenomenon is noted in all the necking criteria too.
Dynamic hardening properties identification utilizing acceleration data by the Virtual Fields Method
Authors: Kim Ji-Min , Kim Jin-Hwan , Barlat Frédéric
Published: November 2020

Finite element (FE) simulations are very important in the field of automotive, aerospace and defense to evaluate crashworthiness of high strength reinforcing parts. Reliable material properties at high strain rates should be used for the FE simulation to acquire accurate simulation results. However, at high strain rates, it is difficult to obtain accurate stress-strain data because reasonable load data is not easily achieved from the experiments due to ringing problem caused by inertia effect. In this study, the virtual fields method (VFM) which is one of the inverse methods suggests another possibility of identifying hardening properties by utilizing acceleration data from the experiments without using load data. In the current study, a methodology is introduced for this purpose. The minimum magnitude of acceleration necessary to retrieve the hardening properties at high strain rate testing is investigated numerically and experimentally. In addition, a new type of high strain rate testing equipment, impact frame high speed tester (IFHS) is described. Various aspects allowing an increase of the acceleration magnitude in the IFHS are discussed for an optimum application of the methodology. Lastly derived hardening properties with the acceleration by the VFM are discussed.
Study of Khan-Huang-Liang (KHL) Anisotropic Deformation Model for Deep Drawing Behaviour of Inconel 718 Alloy
Authors: Mahalle Gauri , Salunke Omkar , Kotkunde Nitin , Kumar Gupta Amit , Singh Swadesh Kumar
Published: November 2020

Study of anisotropic deformation behavior of a material plays a crucial role in optimizing hot working process parameters and trustworthy Finite Element (FE) analysis in sheet metal forming processes. In this work, Khan–Huang–Liang (KHL) phenomenological based constitutive model and anisotropic yield criteria has been formulated for Inconel 718 alloy. Firstly, uniaxial tensile tests have been conducted at different temperatures (room temperature -700°C) and slow strain rates (0.0001-0.1s-1) conditions. KHL constitutive model has been formulated and validated with experimental flow stress data. The prediction capability of the model is evaluated based on correlation coefficient (R), average absolute error, AAE (Δ) and its standard deviation (s). Subsequently, anisotropic yielding behavior of Inconel 718 alloy is predicted based on KHL yield criterion. Anisotropic coefficient (Lankford parameters) and tension compression asymmetry parameters have been calculated experimentally. The prediction capability of KHL yield criterion is analyzed based on yield locus, yield stress variation and anisotropic coefficient variation. The quality index of performance, namely global accuracy index (β) is evaluated. Further, Finite Element (FE) analysis has been carried out for deep drawing of Inconel 718 alloy using commercially available ABAQUS software. The developed KHL constitutive model and anisotropic yield criterion has been incorporated in FE simulation using UMAT/VUMAT code. The FE results are validated with experimental deep drawn cups at different process conditions.
Effect of cooling system in hot stamping process
Authors: Narayanasamy P Srimon , Singh Amarjeet Kumar , Narasimhan K
Published: November 2020

Hot stamping process is used to produce automotive components that give a high strength-to-weight ratio, therefore it reduces fuel consumption and improves crashworthiness. Hot stamping is a non-isothermal process where forming and quenching takes place simultaneously. One of the major factors affecting the mechanical properties of components is the cooling rate which is controlled by the cooling systems. Direct cooling and indirect cooling (cooling channel) are the two cooling methods used in this process. In direct cooling, water is used as the cooling medium that gives higher cooling rate, however it induces large residual stress in the final component. In indirect cooling, cooling channels are used in die and punch for cooling purpose. In indirect cooling system residual stresses are not developed, but thinning occurs in wall region of the blank due to inhomogeneous contact between blank and die. Therefore, in this work, a new method has been proposed with the combination of direct and indirect cooling. In this combined cooling method, different coolant like spray water, air mist and compressed air was used for direct cooling. Simulation of the proposed approach was done by using PAMSTAMP software. The effect of the combined cooling system with various cooling medium was investigated and it was found that the air mist cooling with indirect cooling system resulted in 7% improvement in thickness distribution and 20% improvement in temperature distribution compared to the conventional method.
Identification of the anisotropic plasticity using the virtual fields method for 2024 aluminium alloy
Authors: Fu J W , Xie W W , Ma Z , Qi L H
Published: November 2020

In this work, the virtual fields method was applied to identify the anisotropic plastic constitutive parameters for the wrought 2024 aluminium alloy. First, low cyclic tension-compression tests were conducted for the specifically designed aluminium alloy specimens on a hydraulic universal testing machine and the full-field deformations measured by digital image correlation. Then, the measured experimental data were used to simultaneously identify the constitutive parameters of the Hill 1948 yield criterion and the nonlinear kinematic hardening model based on the virtual fields method. Reasonable identified parameters were obtained. The fitting curves of the virtual work during the minimization process verify the reliability of the identification results.
Evaluation of Sliding Wear Behaviour for STD11 Coated with TiCN Using the Pin-on-Disk Test
Authors: Bang J H , Song J H , Bae G H , Park N S , Choi S O , Lee M G , Kim H G
Published: November 2020

The forming process using ultra high strength steel (UHSS) may cause early damage than the expected lifetime of the tool surface due to the high reaction force of the material compared to the conventional steel sheet. This leads to the increase in the cost of maintenance of the tool and the decrease in the product productivity and quality. In this study, the sliding wear behavior of the titanium carbonitride (TiCN) physical vapor deposition (PVD) coated pin against UHSS was quantitatively evaluated from the pin-on-disk test based on the Taguchi method. S/N ratio and ANOVA are used to evaluate the sensitivity of process parameters affecting on the pin wear depth. Finally, a wear prediction model for the TiCN coated pin against UHSS was constructed by the power law equation.
Prediction of limit strains during non-proportional load paths with a change in loading direction
Authors: Volk W. , Gruber M. , Norz R.
Published: November 2020

Many different models have been published to predict failure after non-proportional load paths. Most of those models are phenomenological and heuristical models. They require a profound knowledge about the material. Examples are the enhanced Modified Maximum Force Criterion (eMMFC), the Polar Effective Plastic Strain-model (PEPS) or the Generalized Forming Limit Concept (GFLC). In addition to the load path, the loading direction has a significant influence on the formability of sheet metals. The mentioned models currently neglect this influence. By extending the GFLC-model by the parameter of loading direction, this influence is taken into account. By analyzing an acceptable number of bi-linear experiments, it is possible to calibrate the proposed model for a micro-alloyed steel HC340LA. Therewith an arbitrary load path with a change in loading direction can be evaluated. The results of this contribution show the effectiveness of this approach by different experiments.
Compensation of elastic die and press deformations during sheet metal forming by optimizing blank holder design
Authors: Burkart M , Essig P , Liewald M , Beck M , Mueller M
Published: November 2020

Shortened product development processes of car body components made of sheet metal combined with the upcoming lack of experts and craftsmen’s in that field do challenge car manufacturers fundamentally. Required tryout time phases and manufacturing costs of complete die sets for car body panels are significantly influenced by their proper function in production and therefore by their highly developed manufacturing process. Looking in more detail, elastic deformation of costed two components and forming press behaviour under load impacts the contact areas between the sheet metal and the load specific spotted areas of the tool. Especially in deep drawing such contact areas between matrice and blank holder are strongly influenced by the sheet metal properties and the part flange behaviour in terms of thickening and thinning during the process. Modern advanced forming simulation models indeed increase precision of sheet metal forming simulation remarkably. For example, new friction models and structural modelling of forming die and forming press components do improve simulation accuracy, while still using rigid tool components. Considering tool stiffness and press deformation in the die design by generating specific blank or geometries via stiffness optimisation, elastic deformations and pressure distribution presumably can be homogenised. In this respect, this paper presents a numerical approach for minimising elastic deformations in drawing operations and thus reducing trial time in the early engineering face. Here a stiffness optimised blank holder is designed based on topology optimisation, taking into account press deformation characteristics such as used drawing pins underneath the blank holder and the drawing cushion box integrated in the press bolster. Afterwards, the new designs compared to conventionally designed die based on structural simulations. The main finding of this contribution is that new approach presented on the one hand leads to improved tool stiffness and reduced tryout effort and more robust production conditions on the other hand.
Study on the Anti-friction properties of Chemically Etched surface texture and its synergistic Anti-friction properties with nano-lubricating oil in sheet metal deep drawing process
Authors: Mei Tangjie , Zhang Dongliang , Zhang Qi
Published: November 2020

In sheet metal deep drawing process, the sliding contact between mold and sheet metal will cause friction and wear between sheet metal and die, resulting in tensile breaking and die wear, which will not only shorten the service life of die seriously, but also lead to quality decline and the rising costs of the forming process. In this paper, an anti-friction method using chemically etched surface texture collocated with graphene nanoparticles added lubricating oil was proposed to reduce the COF between sheet metal and die during sheet metal deep drawing process. Several surface textures with different parameters were obtained by surface chemical etching treatment on the die. The surface texture was observed by Laser Confocal Microscope. The results show that the surface texture after corrosion consists of micron-scale convex and concave, in the process of friction, when the pressure is higher than 72 MPa, the concave in the surface texture forms a closed oil concave because of plastic deformation, lubricating oil provides static pressure bearing capacity in the closed oil concave, sheet metal was separated by the oil from die contact surface, which effectively reduced the COF. In addition, the anti-friction properties ware tested, which showed that when the mass fraction of graphene nanoparticles added is 0.3%, stable deposited film in the friction contact interface can be formed, and a good filling effect of the lubricating oil in the sealed oil concave can be guaranteed, which can preserve a better integrity of the surface texture.
Prognostic Significance of CD30 in Transformed Mycosis Fungoides
Authors: Travaglino Antonio , Russo Daniela , Varricchio Silvia , Pignatiello Sara , Baldo Antonello , Picardi Marco , Pane Fabrizio , Mascolo Massimo
Published: November 2020

Objectives

Several studies suggested that CD30 expression is a favorable prognostic marker in transformed mycosis fungoides (tMF). However, evidence in this field is still unclear. This systematic review and meta-analysis aimed to evaluate the prognostic significance of CD30 in tMF.

Methods

Electronic databases were searched from their inception to June 2020 for all studies assessing the prognostic value of CD30 in tMF. Pooled hazard ratio (HR) for death was calculated; a P value less than .05 was considered significant. Inconsistency index (I2) was used to assess statistical heterogeneity among studies.

Results

Seven studies with 323 patients were included. CD30 expression in tMF was significantly associated with a decreased hazard of death both on univariate (HR, 0.459; 95% confidence interval [CI], 0.319-0.660; P < .001) and multivariate analysis (HR, 0.503; 95% CI, 0.345-0.734; P < .001), and the statistical heterogeneity among studies was null in all analyses (I2 = 0%).

Conclusions

tMF cases with CD30 expression in large cells have a hazard of death two times lower than CD30-negative cases.
Does Prolonged Education Causally Affect Dementia Risk When Adult Socioeconomic Status Is Not Altered? A Swedish Natural Experiment in 1.3 Million Individuals
Authors: Seblova Dominika , Fischer Martin , Fors Stefan , Johnell Kristina , Karlsson Martin , Nilsson Therese , Svensson Anna C , Lövdén Martin , Lager Anton
Published: November 2020

Intervening on modifiable risk factors to prevent dementia is of key importance, since progress-modifying treatments are not currently available. Education is inversely associated with dementia risk, but causality and mechanistic pathways remain unclear. We aimed to examine the causality of this relationship in Sweden using, as a natural experiment, data on a compulsory schooling reform that extended primary education by 1 year for 70% of the population between 1936 and 1949. The reform introduced substantial exogenous variation in education that was unrelated to pupils’ characteristics. We followed 18 birth cohorts (n = 1,341,842) from 1985 to 2016 (up to ages 79–96 years) for a dementia diagnosis in the National Inpatient and Cause of Death registers and fitted Cox survival models with stratified baseline hazards at the school-district level, chronological age as the time scale, and cohort indicators. Analyses indicated very small or negligible causal effects of education on dementia risk (main hazard ratio = 1.01, 95% confidence interval: 0.98, 1.04). Multiple sensitivity checks considering only compliers, the pre-/post- design, differences in health-care-seeking behavior, and the impact of exposure misclassification left the results essentially unaltered. The reform had limited effects on further adult socioeconomic outcomes, such as income. Our findings suggest that without mediation through adult socioeconomic position, education cannot be uncritically considered a modifiable risk factor for dementia.
English School—“Chinese IR” Engagements: Order, Harmony, and the Limits of Elitism in Global IR
Authors: Williams John
Published: November 2020

This article addresses ongoing discussions across the English School (ES) of International Relations (IR) theory and IR theory drawing on Chinese philosophical traditions and Chinese history as exemplifying a “Global IR” approach. However, common interests in long-run history, non-material forms of power, and an international social structure have not yet led to sustained discussion of normative issues important to both approaches. Showing how analytical commonalities between ES and “Chinese” IR accounts of international societies and concepts of order and harmony focus on elite-level perspectives and priorities, I draw on critical and decolonial aspects of Global IR to argue for alternative accounts. Unexplored potential for this exists within the distinct methodological bases of ES and “Chinese IR,” opening space for normative engagement that can provide a model for other inter-tradition encounters in Global IR.
DoNotRead the Latin: Latin as Satanic Signifier in Supernatural Horror Cinema
Authors: Banner Nicholas
Published: November 2020

This article examines the tropological use of the Latin language to evoke the diabolical in supernatural horror cinema. When Latin is intoned in a suitably Gothic context, horror-savvy audiences have every reason to foresee the Devil and his minions arriving in short order, and are rarely disappointed. This article examines the genealogy of this trope, modelling the prolegomena to an intellectual history of cinematic Satanic Latin. The first part of the analysis traces the development of the trope through literature via the European and American Gothic traditions, the writings of the Decadents, and supernatural horror literature. The analysis then broadens to encompass Occultism, the occult, and ‘occulture’ more generally as important aspects of the discourse-community within which Satanic Latin functions. Finally, the scholarly concept of ‘re-enchantment’ from the history of religions is brought to bear on the semiotic role of Satanic Latin in its performative cinematic context.
Antiepileptic rufinamide and QTc interval shortening in a patient with long QT syndrome: case report
Authors: Mondal Tapas , Sullivan Kristen , Divakaramenon Syam , Hamilton Robert M
Published: November 2020

Background

There is limited pharmacologic therapy to reduce the QT interval in hereditary long QT syndrome (LQTS).

Case summary

We describe a child with Allan–Herndon–Dudley syndrome, Lennox–Gastaut epileptic syndrome (LGS), and LQTS Type 1 (LQTS1). Rufinamide was added to his antiepileptic medications to improve seizure control and was noted to be associated with a marked improvement in electrocardiogram QT interval. To the best of our knowledge, this is the first reported case of successful pharmacologic shortening of the QT interval in LQTS1.

Discussion

This case report highlights the potential benefits of rufinamide, a drug associated with mild QT shortening in normal individuals, to markedly reduce and normalize QT duration in a subject with LQTS1.
Dual attenuation peaks revealing mesoscopic and microscopic fluid flow in partially oil-saturated Fontainebleau sandstones
Authors: Zhao Liming , Tang Genyang , Sun Chao , Zhao Jianguo , Wang Shangxu
Published: November 2020

We conducted stress–strain oscillation experiments on dry and partially oil-saturated Fontainebleau sandstone samples over the 1–2000 Hz band at different confining pressures to investigate the wave-induced fluid flow (WIFF) at mesoscopic and microscopic scales and their interaction. Three tested rock samples have similar porosity between 6 and 7 per cent and were partially saturated to different degrees with different oils. The measurement results exhibit a single or two attenuation peaks that are affected by the saturation degree, oil viscosity and confining pressure. One peak, exhibited by all samples, shifts to lower frequencies with increasing pressure, and is mainly attributed to grain contact- or microcrack-related squirt flow based on modelling of its characteristics and comparison with other experiment results for sandstones. The other peak is present at smaller frequencies and shifts to higher frequencies as the confining pressure increases, showing an opposite pressure dependence. This contrast is interpreted as the result of fluid flow patterns at different scales. We developed a dual-scale fluid flow model by incorporating the squirt flow effect into the patchy saturation model, which accounts for the interaction of WIFFs at microscopic and mesoscopic scales. This model provides a reasonable interpretation of the measurement results. Our broad-frequency-band measurements give physical evidence of WIFFs co-existing at two different scales, and combining with modelling results, it suggests that the WIFF mechanisms, related to pore microstructure and fluid distribution, interplay with each other and jointly control seismic attenuation and dispersion at reservoir conditions. These observations and modelling results are useful for quantitative seismic interpretation and reservoir characterization, specifically they have potential applications in time-lapse seismic analysis, fluid prediction and reservoir monitoring.
Northern Chile intermediate-depth earthquakes controlled by plate hydration
Authors: Cabrera Leoncio , Ruiz Sergio , Poli Piero , Contreras-Reyes Eduardo , Osses Axel , Mancini Renzo
Published: November 2020

We investigate the variations of the seismic source properties and aftershock activity using kinematic inversions and template-matching for six large magnitude intermediate-depth earthquakes occurred in northern Chile. Results show similar rupture geometry and stress drop values between 7 and 30 MPa. Conversely, aftershock productivity systematically decreases for the deeper events within the slab. Particularly, there is a dramatic decrease in aftershock activity below the 400–450 °C isotherm depth, which separates high- and low-hydrated zones. The events exhibit tensional focal mechanisms at unexpected depths within the slab, suggesting a deepening of the neutral plane, where the extensional regimen reaches the 700–800 °C isotherm depth. We interpret the reduction of aftershocks in the lower part of the extensional regime as the absence of a hydrated-slab at those depths. Our finding highlights the role of the thermal structure and fluids in the subducting plate in controlling the intermediated-depth seismic activity and shed new light in their causative mechanism.
Heart transplant outcomes in patients with mechanical circulatory support: cold storage versus normothermic perfusion organ preservation
Authors: Sponga Sandro , Benedetti Giovanni , de Manna Nunzio Davide , Ferrara Veronica , Vendramin Igor , Lechiancole Andrea , Maiani Massimo , Nalon Sandro , Nalli Chiara , Di Nora Concetta , Bortolotti Uberto , Livi Ugolino
Published: November 2020

OBJECTIVES

Patients with mechanical circulatory support bridged to a heart transplant (HTx) are at higher risk of postoperative graft dysfunction. In this subset, a mode of graft preservation that shortens graft ischaemia should be beneficial.

METHODS

The outcomes of 38 patients on mechanical circulatory support (extracorporeal life support, left ventricular assist device and biventricular assist device) who received a HTx between 2015 and 2020 were analysed according to the method of graft preservation: cold storage (CS) group, 24 (63%) or ex vivo perfusion (EVP) group, 14 (37%).

RESULTS

The median age was 57 (range 30–73) vs 64 (35–75) years (P = 0.10); 88% were men (P = 0.28); extracorporeal life support was more frequent in the CS group (54% vs 36%; P = 0.27) versus left ventricular and biventricular assist devices in the EVP group (46% vs 64%; P = 0.27). Clamping time was shorter in the EVP group (P < 0.001) and ischaemic time >4 h was higher in the CS group (P = 0.01). Thirty-day mortality was 13% (0–27%) in the CS group and 0% (P = 0.28) in the EVP group. A significantly lower primary graft failure [7% (0–23%) vs 42% (20–63%); P = 0.03] was observed in the EVP group. Survival at 1 year was 79 ± 8% (63–95%) in the CS group and 84 ± 10% (64–104%) in the EVP group (P = 0.95).

CONCLUSIONS

Our results support the use of ex vivo graft perfusion in patients on mechanical circulatory support as a bridge to a HTx. This technique, by shortening graft ischaemic time, seems to improve post-HTx outcomes.
Investigating the causal effect of maternal vitamin B12 and folate levels on offspring birthweight
Authors: Moen Gunn-Helen , Beaumont Robin N , Grarup Niels , Sommer Christine , Shields Beverley M , Lawlor Deborah A , Freathy Rachel M , Evans David M , Warrington Nicole M
Published: November 2020

Background

Lower maternal serum vitamin B12 (B12) and folate levels have been associated with lower offspring birthweight, in observational studies. The aim of this study was to investigate whether this relationship is causal.

Methods

We performed two-sample Mendelian randomization (MR) using summary data on associations between genotype-B12 (10 genetic variants) or genotype-folate (four genetic variants) levels from: a genome-wide association study of 45 576 individuals (sample 1); and both maternal- and fetal-specific genetic effects on offspring birthweight from the latest Early Growth Genetics consortium meta-analysis with 297 356 individuals reporting their own birthweight and 210 248 women reporting their offspring's birthweight (sample 2). We used the inverse variance weighted method, and sensitivity analyses to account for pleiotropy, in addition to excluding a potentially pleiotropic variant in the FUT2 gene for B12 levels.

Results

We did not find evidence for a causal effect of maternal or fetal B12 levels on offspring birthweight. The results were consistent across the different methods. We found a positive causal effect of maternal folate levels on offspring birthweight [0.146 (0.065, 0.227), which corresponds to an increase in birthweight of 71 g per 1 standard deviation higher folate]. We found some evidence for a small inverse effect of fetal folate levels on their own birthweight [−0.051 (−0.100, −0.003)].

Conclusions

Our results are consistent with evidence from randomized controlled trials that higher maternal folate levels increase offspring birthweight. We did not find evidence for a causal effect of B12 levels on offspring birthweight, suggesting previous observational studies may have been confounded.
The Interplay of Online Network Homogeneity, Populist Attitudes, and Conspiratorial Beliefs: Empirical Evidence From a Survey on German Facebook Users
Authors: Cargnino Manuel
Published: November 2020

Social networking sites are suspected to impede the communication between members of different political camps and thereby increase network homogeneity. This homogeneity can be a result of humans’ tendency to process information in confirmatory ways—a characteristic which is also ascribed to populist citizens and those who hold conspiratorial beliefs. It is hypothesized that populist views and conspiratorial beliefs are associated with higher exposure to like-minded information within Facebook. An online survey with German Facebook users (N = 469) revealed that populist attitudes are positively associated with conspiratorial beliefs but negatively associated with homogeneity. Conspiratorial beliefs are unrelated to homogeneity. Findings are discussed in the light of extant research.
A unified theory for continuous-in-time evolving finite element space approximations to partial differential equations in evolving domains
Authors: Elliott C M , Ranner T
Published: November 2020

We develop a unified theory for continuous-in-time finite element discretizations of partial differential equations posed in evolving domains, including the consideration of equations posed on evolving surfaces and bulk domains, as well as coupled surface bulk systems. We use an abstract variational setting with time-dependent function spaces and abstract time-dependent finite element spaces. Optimal a priori bounds are shown under usual assumptions on perturbations of bilinear forms and approximation properties of the abstract finite element spaces. The abstract theory is applied to evolving finite elements in both flat and curved spaces. Evolving bulk and surface isoparametric finite element spaces defined on evolving triangulations are defined and developed. These spaces are used to define approximations to parabolic equations in general domains for which the abstract theory is shown to apply. Numerical experiments are described, which confirm the rates of convergence.
Log orthogonal functions: approximation properties and applications
Authors: Chen Sheng , Shen Jie
Published: November 2020

We present two new classes of orthogonal functions, log orthogonal functions and generalized log orthogonal functions, which are constructed by applying a $\log $ mapping to Laguerre polynomials. We develop basic approximation theory for these new orthogonal functions, and apply them to solve several typical fractional differential equations whose solutions exhibit weak singularities. Our error analysis and numerical results show that our methods based on the new orthogonal functions are particularly suitable for functions that have weak singularities at one endpoint and can lead to exponential convergence rate, as opposed to low algebraic rates if usual orthogonal polynomials are used.
Space–time discontinuous Galerkin approximation of acoustic waves with point singularities
Authors: Bansal Pratyuksh , Moiola Andrea , Perugia Ilaria , Schwab Christoph
Published: November 2020

We develop a convergence theory of space–time discretizations for the linear, second-order wave equation in polygonal domains $\varOmega \subset{\mathbb R}^2$, possibly occupied by piecewise homogeneous media with different propagation speeds. Building on an unconditionally stable space–time DG formulation developed in Moiola & Perugia (2018, A space–time Trefftz discontinuous Galerkin method for the acoustic wave equation in first-order formulation. Numer. Math., 138, 389–435), we (a) prove optimal convergence rates for the space–time scheme with local isotropic corner mesh refinement on the spatial domain, and (b) demonstrate numerically optimal convergence rates of a suitable sparse space–time version of the DG scheme. The latter scheme is based on the so-called combination formula, in conjunction with a family of anisotropic space–time DG discretizations. It results in optimal-order convergent schemes, also in domains with corners, with a number of degrees of freedom that scales essentially like the DG solution of one stationary elliptic problem in $\varOmega $ on the finest spatial grid. Numerical experiments for both smooth and singular solutions support convergence rate optimality on spatially refined meshes of the full and sparse space–time DG schemes.
HIV, Immune Dysfunction, and the Natural History of Anal High-Risk Human Papillomavirus Infection in Gay and Bisexual Men
Authors: Poynten I Mary , Jin Fengyi , Garland Suzanne M , Hillman Richard J , Molano Monica , Roberts Jennifer M , Templeton David J , Phillips Samuel , Law Carmella , Fairley Christopher K , Farnsworth Annabelle , Grulich Andrew E
Published: November 2020

Background

Incidence of anal cancer is highest in gay and bisexual men (GBM). Better understanding of the natural history of anal high-risk human papillomavirus (hrHPV) infection is needed for anal cancer prevention.

Methods

The Study of the Prevention of Anal Cancer was a 3-year study of Australian GBM, aged 35 years or older. We examined incidence, clearance, and risk factors for 13 hrHPV types at baseline and 3 annual visits.

Results

In 525 men with ≥ 2 visits, 348 (66.3%) acquired ≥ 1 incident hrHPV infection. HPV16 incidence rates were similar, but non-16 hrHPV incidence was higher in HIV-positive (51.8/100 person years [PY]) than HIV-negative men (36.5/100 PY, P < .001). Annual clearance rates of HPV16 (13.21/100 PY, 95% confidence interval, 10.53–16.56) were lower than for other hrHPV types. hrHPV clearance rates were not associated with HIV overall but were significantly lower in those with a lower nadir CD4 (<200 cells/µL) for HPV16 (P = .015) and other hrHPV types (P = .007).

Conclusions

Higher incidence of non-16 hrHPV types, coupled with lower clearance of non-16 hrHPV types in those with past impaired immune function, is consistent with the greater role of non-16 hrHPV in anal cancer in HIV-positive people.

Australia New Zealand Clinical Trials Registry

ANZCTR365383.
PCT Kinetics in the First Week Postburn for Sepsis Diagnosis and Death Prognosis—An Accuracy Study
Authors: Cabral Luís , Fernandes Mariana , Marques Sérgio , Meireles Rita , Caetano Marisa , Afreixo Vera
Published: November 2020

Despite continuous advances in burn care, sepsis is still the main cause of death in burn patients. Procalcitonin (PCT) has been reported as an accurate sepsis biomarker and also as a fair predictor of death. The aim of this study was to assess PCT kinetics in the first week postburn regarding sepsis diagnosis and death prognosis. Sample included 142 patients with ≥15% TBSA, admitted from January 2011 to December 2014 at Coimbra Burns Unit, Portugal. Sepsis diagnosis was done according to American Burn Association criteria. PCT range and median values in the first 7 days after burns were statistically analyzed for its potential for sepsis diagnosis and death prognosis. A subanalysis was done regarding TBSA, sex, age, and inhalation injury. First week PCT range and median were significant for sepsis diagnosis and death prognosis, but the median area under the curve was greater in the last case. TBSA influenced PCT accuracy, which was greater for TBSA less than 40% either for diagnosis or prognosis. Age was inversely related to the accuracy, being better in younger than 40 years in both cases. PCT diagnostic accuracy was not affected by sex, opposing to the prognostic one which is better in women. Inhalation injury had no effect on diagnostic accuracy, but it happens with prognostic accuracy. PCT levels’ variation is related to sepsis evolution and outcome. Its median performs better than its range. Always coupled with clinical examination, monitoring PCT levels kinetics may help early sepsis detection, potentially reducing morbidity and mortality, being also useful for death prognosis.