bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental and numerical investigations on overall buckling of steel pipe truss with circular cutout on the compression element
Authors: Iman Miftahul , Suhendro Bambang , Priyosulistyo Henricus , Muslikh
Published: January 2019

Pitting corrosion, an extremely localized corrosion that leads to the creation of small holes in metal when a protective coating is damaged could trigger structural failure in platform structures. A single pit in a critical point, especially in compression element, can cause a great deal of reduction in overall buckling capacity of the structure. This study aims to indicate the effect of a circular cutout, representing a pitting corrosion on overall buckling capacity of steel pipe truss structure subject to static loading. Five models of truss structure having a circular cutout on their compression elements had been tested experimentally up to failure. The truss structures were made of steel pipes and contain only 2 elements as representation of part of real platform. The single cutout were located at 0.5L, 0.25L and 0.125L, where L is the length of the compression element. Two models without cutout had been used as control models. The overall buckling capacity of the truss were compared to similar truss based on the element buckling of compression element. The experimental test results, represented by nonlinear load deflection curves and their associated critical loads as well as buckling modes, had been verified numerically by eigenvalue and geometric nonlinear finite element analyses utilizing 3D solid elements on ABAQUS. The results showed that: (a) in the truss model with various hole positions, the overall buckling loads were slightly higher than that of element buckling loads: (b) the presence of cutout reduced the overall buckling capacity of the structure, (c) the capacity reduction factors depend on the cutout locations and (d) the lowest capacity reduction factor of 0.882 was associated with the presence of cutout at the middle of compression element.
Investigating the Mechanism of Shear Fatigue in Reinforced Concrete Beams subjected to Pulsating and Moving Loads using Digital Image Correlation
Authors: Suryanto Benny , Staniforth George , Kim Jaehwan , Gebreyouhannes Esayas , Chijiwa Nobuhiro , Fujiyama Chikako , Woodward Peter K.
Published: January 2019

An experimental investigation on three shear-critical reinforced concrete beams was performed to investigate the mechanism of shear fatigue. The first beam was simply tested to failure under monotonic loading to determine the static capacity, whereas the other two were subjected to repetitive loading below its static capacity to failure. Of these two beams, one was subjected to a stationary pulsating load at midspan while the other was subjected to a step-wise moving load along the span. During each experiment, the crack pattern was monitored throughout using an automated crack mapping employing the digital image correlation technique. The results show that each beam exhibited a unique crack pattern which could be characterised as shear-flexure in nature. It is shown the nature of crack propagation under monotonic loading is dissimilar to that under repetitive loading, especially when the load is not stationary. Moving load is also shown to cause greater damage to the beam than the stationary pulsating load and result in a reduction in fatigue life by almost two orders of magnitude.
Beam-to-Beam Connection of Precast Concrete Structures: State of the Art
Authors: Hery Kristiyanto , Andreas Triwiyono , Muslikh  , Ashar Saputra
Published: January 2019

The use of precast concrete is known to improve productivity, quality control, and cost efficiency in reinforced concrete structure. The Connection is the most important aspect of precast concrete structures. The connection transfers force between the precast components, determine strength, stiffness, and ductility of the whole structure. Providing joint in the beam-column connection region always cause difficulties during the erection stage. Relocation of the connection at a certain distance from the column to the beam span is an alternative solution that creates the beam-to-beam connection. It will be much easier to assemble the connection that consists of some joints. Research and application of the precast concrete beam-to-beam connection details have published since 1975. This paper reviews the state of the art of research and practical application of beam-to-beam connection system related to connection models, joint locations, and details. It concluded from the review that the developing research leads to improve the performance of earthquake resisting structures
Improvement of shear capacity for precast segmental box girder dry joints by steel fiber and glass fiber
Authors: Smittakorn Watanachai , Manavithayarak Pattraporn , Sukmoung Patra
Published: January 2019

The use of precast segmental box girders in the bridge construction projects yields many benefits: economy, high quality, rapid construction, and minimal disruption to site. Previously, precast segments are connected together by epoxy joints. Epoxy fills in the gaps and makes strong connection, but it takes time and effort in the construction process. Later, dry joints have been introduced in the process, and hence the construction could be done much faster. However, there exists some drawback in using the dry joints. The contact surface between segments, especially at shear keys, can hardly be made smooth and well-fitted together. Consequently, the transferred shear strength cannot be developed to its full capacity. This study is an attempt to improve the capacity of shear strength of dry joints by adding steel fiber and glass fiber into concrete mixture. Considering specimens with single shear key, experiments have been conducted for shear capacities of 5 specimen types: ordinary concrete, concrete mixed with 1% and 2% steel fiber, and concrete mixed with 1% and 2% glass fiber. Results from experiments have shown that steel fiber helps increase the shear capacity of dry joints while glass fiber somehow degenerates the shear capacity and the compressive strength of concrete.
Analysis study the used of Tuned Mass Damper (TMD) on an existing train bridge due to high speed train with moving mass load approach
Authors: Octarena Nugroho Wivia , Rubiana Widarda Dina , Herdha Dwyana Oryza
Published: January 2019

As the need of the train speed increased, the existing bridges need to be evaluated, especially in dynamic responses, which are deformation and acceleration. In this study, Cisomang Bridge is modeled and analyzed due to the high-speed train SJ X2 in varying speeds, 50 km/h, 100 km/h, 150 km/h, and 200 km/h. The used of tuned mass damper also will be varied on its setting and placing. The tuned mass dampers setting be varied based on the first or second natural frequency and the placing of tuned mass damper be varied based on maximum deformation of the first or second mode. Moreover, the tuned mass damper ratio will be varied 1% and 1.6%. For all speed variations, dynamic responses of structure without TMD still fulfil the Indonesian Government Criterion based on PM 60 - 2012 but do not meet requirement of comfort criteria based on DIN-Fachbericht 101. Furthermore, only for the speed train 50km/h dynamic responses of structure fulfil safety criteria based on Eurocode EN 1990:2002, whereas the other speed variations do not meet that requirement. In the use of TMD 1% mass ratio, the structure fulfils the safety criteria for all speed variations. In the use of TMD 1.6% mass ratio, all the structure fulfils the safety and comfort criteria except 100 km/h speed which only fulfils the safety criteria.
Behavior of earthquake-resistant structure elements using polypropylene fiber and high strength reinforcing bars
Authors: Imansyah Maulana Derry , Imran Iswandi , Kamaruddin Kurniawan S. , Aryanto Aris , Riyansyah Muhammad
Published: January 2019

The use of high strength reinforcing bars has becoming an interesting and cost-efficient option in construction industry recently. However, their use is limited due to their low deformability which might induce a brittle collapse in the structures. Also, longer development length is needed to transfer stress from reinforcing bars to the surrounding concrete. This paper focuses on investigating the influence of fibrous concrete and high-strength reinforcing bars on the behavior of structural elements. Five half-scaled specimens of interior joints using plain or fibrous concrete, reinforced with conventional 420 MPa or high strength reinforcing bar of 520 Mpa were experimentally tested. The two specimens of plain concrete, reinforced longitudinally with 16 mm and 19 mm reinforcing bars are defined as control specimens. The other test specimens were casted with Polypropylene fiber reinforced concrete (PFRC) with 16 mm and 19 mm longitudinal reinforcing bar. Loading protocol of all test specimens is defined according to ACI 374.2. The structure behavior, such as dissipated energy, bond between reinforcing bars and surrounding concrete, and stiffness degradation of the four specimens were evaluated and compared. The results obtained shows that the use of fiber increase the dissipated energy up to 27.5 % compared to specimens with plain concrete. Moreover, the peak strength of PFRC specimens was slightly increased (3% - 7%) compared to that of specimens with plain concrete. Moreover, there is an increase in peak-to-peak stiffness at elastic range loading with the addition of fiber, while no significant difference after the yields of longitudinal reinforcing bars.
Finite element analysis and parametric study of EWECS composite columns with double H-shaped steel
Authors: Fauzan  , Kurniawan Ruddy , Al Jauhari Zev
Published: January 2019

The behavior of composite column that consists of an exterior wood panel with concrete encased steel (CES) core, hereafter referred to as Engineering Wood Encased Concrete-Steel (EWECS) composite columns, is investigated. Nonlinear analysis is done by using finite element software, ANSYS APDL, to study the seismic performance of the columns. Verification of the finite element modeling is done by comparing and corresponding experimental result that reported by one of the authors, then it is used as a reference for parametric study. The parameters in the parametric study are the use of fiber reinforced concrete (FRC), the use of Indonesian wood and the use of friction element. The results are presented in the form of hysteresis characteristics, failure mode, and principal stress distribution. It is demonstrated that the seismic performance of the EWECS composite columns can be accurately predicted by proposing finite element modeling. Obtained results from the parametric study show that various FRC, different wood, and the contact element influences the hysteresis loops and behavior of the columns. The flexural capacity of the columns is improved about 7-17% by adding steel fiber. In addition, the typical Indonesian wood (Matoa) enhances the flexural strength about 3.3%. Moreover, the use of a friction element affects the seismic behavior significantly.
Fundamental study on spontaneous corrugation pattern on dry sand due to moving vehicle
Authors: Ikeda Aiko , Hashimoto Kai , Srimahachota Teeranai , Zheng Hao , Kanie Shunji
Published: January 2019

On unpaved or snowy icy roads, it is known that corrugation pattern on road surface spontaneously emerges due to the repetition of loading by vehicle, and this phenomenon is named washboard road. Washboard road on snowy icy road causes serious problem on the driving of vehicles because the braking performance deteriorates due to lack of friction between road surface and tires. The authors developed an indoor experimental device to reproduce similar phenomenon in a laboratory. As the first step of the study, we chose fine dry sand as a surface material and we successfully reproduced the corrugation on the track. After scrutinizing the growing process of corrugation, we found that the running velocity of the track and the natural frequency of the oscillator are the most important factors for the growth. However, the frequencies of the corrugation converge to some specific value which is different from the natural frequency of the oscillator. Further, we adopted different road materials such as saturated sand, artificial snow and natural snow. This paper introduces interesting findings on formation process of washboard road.
Influence of environmental temperature and moisture conditions on fatigue resistance of concrete
Authors: Koda Yasuhiro , Minakawa Shohei , Iwaki Ichiro
Published: January 2019

It is known that the fatigue resistance of concrete decreases when the concrete is saturated with water and that the compressive strength increases with increasing water content at low temperatures below the freezing point of water. However, there have been few systematic studies on the influence of the ambient temperature and moisture content on the fatigue resistance of concrete. In the present study, static loading and fatigue tests were carried out on concrete cylinders to determine their fatigue resistance under compression. The test methods had been conducted to considered environmental temperatures and water contents. The results indicated that at room temperature, the static compressive strength decreases with increasing moisture content. In contrast, at a low temperature, the compressive strength of the samples increased with increasing moisture content. Furthermore, regardless of the temperature, the fatigue resistance decreased as the moisture content increased.
Nonlinear finite element and fiber element analysis of concrete filled square steel tubular (cfst) under static loading
Authors: Effendi Mahmud Kori , Abdul Hamid Nor Hayati
Published: January 2019

The combination of thin-walled steel structure with concrete infill can be used as the alternative material properties in the building in Indonesia. This composite material is suitable for seismic-resistant building because it has more ductility than conventional material. In the tsunami event, some tsunami debris strikes the building and induced partial or full collapse of the building. The loading tip shape of tsunami debris which contacts to a tubular surface affects the local deformation or buckling mode of the thin-walled structures. In order to investigate the effects, we conducted three-dimensional nonlinear finite element analyses of concrete filled square steel tubular members subjected to concentrated lateral loads by using the finite element analysis (FEM) program MSC Marc/Mentat. The fiber element analysis is also performed to reduce the analysis time of FEM and simplify the analysis. The accuracy of the FEM and fiber element analysis is verified by the experiment. Being based on the parametric numerical study, it discusses the effect of axial load on the load-deflection relations. It shows that the higher the axial load, the more degradation the ductility of the structure.
Smart Logistics Framework: A Case Study of Phuket RO Water System
Authors: Werapun Warodom , Srimala Wisit , Chaowanawatee Kullawat , Karode Thanakorn
Published: January 2019

The product transportation is an important procedure in businesses, which consumes costs and times. Effective transportation management can reduce expenses significantly. New technologies such as Global Position System (GPS), maps, notification and network connection can be integrated all together in one small smart phone that provides accessing from anytime and anywhere. In this paper, we propose a smart logistics framework that combines different technologies in order to solve management and tracking issues in a real transportation environment.
Public preference towards the integration of krl and transjakarta tariff
Authors: Kusuma Andyka , Tjahjono Tri , Syaputri Alviana Dwi
Published: January 2019

Transportation costs in Jakarta reach 30% of the total income of the community every month while the standard that has been set by World Bank is only 10%. This paper discusses the result of willingness-to-pay study conducted at Sudirman railway station in the downtown of Jakarta with the purpose of reducing transportation cost by implementing the tariff integration system of KRL and Transjakarta. The data was collected by the methods of stated preference survey with commuters as the respondent.The survey was conducted by asking the respondents some questions including respondents’ socio-economic characteristic, travel distance, and travel choice exercise. The existing modes that will be compared are motorcycle and bus (kopaja). Motorcycle is the mode whom commuters mostly use with 62% while kopaja is only 38%. The data was analyzed by using discrete choice model and utility function. Based on the analysis, parameters that influence commuters to shift from existing modes to transjakarta are saving time, saving fare, transportation expenditure, and education level. Moreover, the study found that the cheaper the integration tariff offered, the greater the probability of choosing transjakarta services and the faster the travel time of Transjakarta, the greater the probability of choosing transjakarta. Furthermore, each comparison mode has different tariff preferences on the tariff integration system of Transjakarta and KRL.
Security Issues on Smart Grid and Blockchain-based Secure Smart Energy Management System
Authors: Kim Seung Min , Lee Tacklim , Kim Seunghwan , Park Lee Won , Park Sehyun
Published: January 2019

The Smart Grid has emerged to address the shortcomings of one-way existing grid systems, and is the next generation power grid infrastructure that applies smart ICT (Information Communication Technology) to existing grid. The Smart Grid is expected to greatly improve the efficiency and reliability of future power systems with the demand for renewable energy resources. However, because major power facilities are interconnected through communication networks, Smart Grid’s cyber security is becoming an important issue. Cyber-attacks by malicious intruders can lead to serious incidents such as massive outages and the destruction of power network infrastructure, since the cyber-attacks can damage energy data, starting with personal information leakage from grid members. Therefore, as a solution to this issue we will suggest a secure smart energy management system based on the blockchain. The blockchain is a distributed data processing technology in which all users participating in the network distribute and store data. Applying blockchain technology to the Smart Grid will enable more secure management of energy data, and furthermore, it will contribute to the development of the future smart energy industry in the future.
Automatic Control Unit for Air-Condition System in Building
Authors: Tanuphol Pairach , Pothisarn Chaichan
Published: January 2019

Electrical energy usage has been rapidly increased in the building sector due to shifting in population from rural to urban area. In the building, Heating, ventilation, and air conditioning (HVAC) system. Especially air-condition system has taken the most substantial proportion of overall building energy consumption. This result from a large amount of energy must be used in order to provide a comfort zone for occupants in the building. So, this paper aims to proposed design and built prototypes of air-condition control unit that can automatically operate according to schedule. The prototypes using a wireless module to send the control signal to the air-conditioning unit. Specific software has been built to set the desired operating schedule and duration of an operation. The performance of the proposed unit will be evaluated using an experiment on actual field test by installing on actual air-condition in the case study building. The result has shown that the proposed unit can reduce energy usage in air-conditioning significantly compare with little cost for the controller unit.
On-line Monitoring of SRM Grain Structure Based on embedded FBG Sensor
Authors: Zhang Lei , Chang Xin-Long , Zhang You-hong , Chen Xiang-dong , Zhang Qing
Published: January 2019

This paper proposes the use of FBG (Fiber Bragg grating) sensors for SRM (Solid Rocket Motor) grain structure continuous Structural Health Monitoring(SHM) as they are generally considered as the preferable solution in flammable and explosive environments, due to their electromagnetic interference immunity and their inherent electrical and explosion safe characteristics. The processes of SRM manufacturing(curing of propellant and demoulding) were monitored. The curing degree of the propellant can be monitored by wavelength change of the FBG sensors, and this provides a new monitoring method for curing of the propellant grain. The monitoring of the demoulding process shows that the sensor is very sensitive to the tensile and compressive stresses on grain and can be used for on-line monitoring of grain in a mechanical environment. In monitoring simulated debonding test, the failure process of crack initiation, expansion and direction all can be monitored by the FBG sensors. After the crack is produced, the location of the debonding can be determined by the variation of the different sensors.
PID Controller Implemented in Festo CDPX
Authors: Podržaj Primož
Published: January 2019

In this paper, we describe the procedure for the implementation of the PID controller in the Festo CDPX operator unit. These units enable the execution of the control algorithm and human machine interface in a single unit. In our laboratory the unit is used to teach the students about the basics of control systems. For this purpose, one of the most common closed loop control systems for the education purposes was selected. It is a water level control system. In this paper the design of the whole system is presented. The need for a PI control algorithm is also explained. The programming of the operator unit CDPX, both in Festo CoDeSys and Designer Studio is explained. Such a simple system has turned out to be a great educational tool for Control Theory and Programmable Logic Controller related subjects.
Static recrystallization kinetics and microstructure evolution of 7055 aluminum alloy
Authors: Zhang Tao , Li Lei , Lu Shihong , Li Zhengfang , Chen Peng , Gong Hai
Published: January 2019

In order to acquire flow characteristics in multi-pass hot plastic deformation and the optimized processing parameters for 7055 aluminum alloy, the double-pass hot compressive flow stress behavior was studied at the temperatures from 300 to 420 °C, the strain from 0.2 to 0.4 and the pass interval time from 10 to 100s on Gleeble-3180 thermo-simulation machine. The static recrystallization (SRX) kinetics and grain size model of 7055 aluminum alloy were acquired by regression analysis. The metallographic tests were conducted and the effects of pass interval time, temperature and strain on microstructure evolution of SRX were analyzed. The results show that 7055 aluminum alloy is temperature sensitive material and the yield flow stress decreases with ascending temperature and pass interval time. Large strain, high temperature and long pass interval time are beneficial to larger SRX fraction and grain refinement. The investigation of flow characteristic and microstructure evolution can be a guidance to acquire optimized processing parameters for multi-pass hot deformation of 7055 aluminum alloy.
Friction stir welding of ultra low carbon steel: microstructure, mechanical properties and electrochemical study
Authors: Koley Ishita , Kundu Sukumar , Kailas Satish V.
Published: January 2019

In the present investigation, the friction stir welding of ultra low carbon steel was carried out at different tool rotational speeds of 300 to 900 rpm in steps of 150 rpm for 30 mm/min traverse speed. The macro and microstructures were examined to identify the different areas of stir zone, thermomechanically affected zone and heat affected zone of the welded joints. Tensile strength of the welded joints was evaluated and maximum tensile strength of ∼336 MPa was obtained at 450 rpm tool rotational speed. Microhardness was measured along the cross section of the welded joint. The maximum hardness was observed at stir zone when compared to thermomechanically affected zone and heat affected zone. The hardness values decreased with the increase in tool rotational speeds in the stir zone. Electrochemical study was investigated in 0.1 mol/L HCl solution using various electrochemical measurements such as open circuit potential, electrochemical impedance spectroscopy and potentiodynamic polarization. The corrosion rate at stir zone decreased with the increase in tool rotational speed.
Reduction of the influence of film thickness on diffuse reflectance spectroscopy measurement of the tongue
Authors: Song Shaoxiu , Zhao Jing , Li Gang , Lin Ling
Published: January 2019

Diffuse reflectance spectroscopy of the tongue contains rich physiological and biochemical information of human status. As it involves contact measurement of the tongue, preventing cross infection during measurement is an important problem to be solved. The use of sterile isolation films is a convenient and efficient way. However, these films can affect the spectral measurement results at the same time. In this paper, to study the influence of films on spectral analysis, a new modeling strategy with good robustness is proposed. The model is established by the use of spectra obtained with different thicknesses of films; thus it is insensitive to the film thickness. The experiment was conducted by gathering spectra of 35 volunteers’ tongue using films of different thicknesses. First, the partial least squares method was used to reveal the relationship between the spectral data and the thickness of films. Second, the support vector machine established a classification model between the spectral data and subjects to study the influence of the film. The results showed that the model established by the new modeling strategy could minimize the error caused by variation of the film thickness.
Design and growth of multi-functional InAsP metamorphic buffers for mid-infrared quantum well lasers on InP
Authors: Jung Daehwan , Yu Lan , Dev Sukrith , Wasserman Daniel , Lee Minjoo Larry
Published: January 2019

We present InAsP multi-functional metamorphic buffers (MFMBs) designed to enable mid-infrared Type-I InAs quantum well (QW) lasers on InP substrates. InAsxP1-x/InP MFMBs with x = 0.5–0.7 provide a versatile platform for Type-I InAs QW laser diodes in the mid-infrared regime by bridging the lattice mismatch between InAs and InP while simultaneously functioning as the bottom cladding layer for laser structures. Cross-sectional transmission electron microscopy shows that InAs multi-QWs can be grown as thick as 15 nm without forming misfit dislocations on an InAs0.7P0.3 buffer, enabling room-temperature photoluminescence at wavelengths >3 μm. We then compare the performance of lasers grown on InAsP MFMBs and show that the temperature dependence strongly depends on the energy band offset between the QW and the metamorphic InAsP waveguides. Future work could improve performance at longer wavelengths by investigating the use of electron blocking layers and adjusting the device design to minimize parasitic heating.
Simulated electron diffraction patterns of ω-Fe in Fe-C martensite
Authors: Ping D. H. , Xiang H. P.
Published: January 2019

A metastable hexagonal ω-Fe phase with its particle size of about 1-2 nm coexists at the {112}<111>-type twinning boundaries in Fe-C martensite. The ω-Fe lattice parameters are dependent on their corresponding body centered cubic (BCC) phase (aω=2abcc,cω=3/2abcc). The above dependence and the unique distribution of the ω-Fe particles at the BCC {112}<111>-type twinning boundaries inevitably cause the overlapping of electron diffraction spots of fine ω-Fe with those of BCC and its twin during transmission electron microscope (TEM) observations. Thus, in order to understand the nature of the ultrafine ω-Fe phase in carbon steels, we have simulated its electron diffraction patterns by means of the commercial CrystalMaker software. In most of the zone axes, which show the electron diffraction pattern with three sets of diffraction spots [(1) the BCC matrix crystal, (2) the corresponding twin crystal, and (3) the possible twinning double diffraction spots] together, the simulated results have shown that the diffraction spots from the ω-Fe phase are all overlapped with those three sets of spots. However, in some specific zone axes, for example, in BCC [112] directions, the diffraction spots from the ω-Fe phase can be uniquely recognized since the BCC {112}<111>-type twinning boundary plane is perpendicular to the observation direction, and thus, no twinning double diffraction spots should be observed theoretically.
Mathematical modeling of Stokes flow in petal shaped pipes
Authors: Xu Zhimin , Song Siyuan , Xin Fengxian , Lu Tian Jian
Published: January 2019

A theoretical model is developed to characterize fully developed laminar flow (Stokes flow) in idealized petal shaped pipes by regarding the pipe wall as a circular boundary having sinusoidal perturbation (or, equivalently, surface roughness). Built upon the method of perturbation, the model quantifies the effects of the relative roughness and wave number of the pipe boundary on the Stokes flow. Approximate solutions of the velocity field, pressure gradient, and static flow resistivity are obtained. The same approach together with the method of Fourier transform is used to deal with low Reynolds flow in pipes having other cross-sectional morphologies such as triangle and square. Results obtained from computational fluid dynamics simulations are used to validate the theoretical model predictions, with good agreement achieved. The presence of surface roughness causes periodic fluctuation and global offset of velocity distribution and enlarges both the pressure gradient and static flow resistivity in petal shaped pipes.
Poisson type operators on the Fock space of type B
Authors: Asai Nobuhiro , Yoshida Hiroaki
Published: January 2019

The main purpose of this paper is to propose an (α, q)-analogue of the Poisson operators on the Fock space of type B in the sense of Bożejko, Ejsmont, and Hasebe [J. Funct. Anal. 269, 1769–1795 (2015)] and to find a probability law of this operator. We shall show that the probability law is expressed by the q-Meixner distribution in the sense of Definition 3.2. Our results contain not only symmetric distributions as in Bożejko-Ejsmont-Hasebe but also the non-symmetric ones such as free Poisson, q and q2-deformations of Poisson, Pascal, Gamma, and Meixner distributions.
Magnetostriction of Fe-Ga coatings and their application in ultrasonic guided wave sensing
Authors: Qi Qingli , Li Jiheng , Ding Zhiyi , Mu Xing , Tang Zhifeng , Bao Xiaoqian , Zhu Jie , Gao Xuexu
Published: January 2019

Fe83Ga17 (at. %) coatings with a thickness of 270-500 μm were prepared on 316L stainless steel by high velocity oxy-fuel spraying technology. The coatings exhibited a lamellar structure, and the magnetostriction reached 34.5 ppm. The magnetostrictive coatings were applied to electromagnetic acoustic transducers (EMATs), where the different bias magnetic fields and coating thicknesses were considered to examine the ultrasonic guided wave sensing capability and the detection sensitivity. The 180-kHz ultrasonic guided waves were captured from artificial defects and the pipe end under different bias magnetic fields. Among them, the EMATs exhibited the best sensing performance under a bias magnetic field of 255.7 Oe. Meanwhile, magnetostrictive stress induced the decrease of the magnetic permeability and the rearranged magnetic moment, resulting in a large strain sensitivity (dλ/dH). Because of the relatively good field sensitivities in magnetization and magnetostriction, the EMATs using Fe83Ga17 coating with a thickness of 500 μm exhibited better detection sensitivity than that of 300 μm. This work provides a good prospect of Fe-Ga alloy coatings applied in non-destructive testing.
A microfluidic device for in situ fixation and super-resolved mechanosensation studies of primary cilia
Authors: Chu Sheng-Han , Lo Li-Lun , Lai Richard Lee , Tony Yang T. , Weng Rueyhung Roc , Liao Jung-Chi , Huang Nien-Tsu
Published: January 2019

The primary cilium plays an important role in mechanosensation in mammalian cells. To understand mechanosensation in the primary cilium, we combined a microfluidic device with super-resolution microscopy to study the primary cilium phenotypes. The microfluidic system enabled the precise control of the flow shear within a well-confined cell-culture environment. In addition, in situ cilia fixation was possible by switching from the culture medium to the fixation buffer instantaneously, which preserved the real-time cilium phenotype under the flow shear. After fixation, multiple cilium-specific proteins were immunostained to quantify the cilia bending behavior. We found that >50% of the primary cilia of mouse inner medullary collecting duct cells were highly aligned with the direction of flow under 11 Pa shear stress. Finally, we used super-resolution microscopy to observe the redistribution of two major cilium-specific proteins under flow shear, acetylated alpha-tubulin, and intraflagellar transport protein 88. To the best of our knowledge, this is the first platform to combine a microfluidic device with super-resolution microscopy to enable flow stimulation and in situ fixation for the observation of ciliary protein. This system can potentially be applied to the future development of a stimulation-enabled organ-on-a-chip to observe the intercellular signaling of primary cilia or for the analysis of disease mechanisms associated with ciliary mutations at the organ level.
On null and causal pseudoconvex space-times
Authors: Vatandoost Mehdi , Pourkhandani Rahimeh , Ebrahimi Neda
Published: January 2019

The condition of pseudoconvexity has important implications for geodesic structures of space-time. Low showed that this condition guarantees the existence of a smooth structure of the space of geodesics. Recently, the place of this property within the causality ladder is in the attention. There is a conjecture which states that every strongly causal space-time is causally simple if and only if it is null pseudoconvex. In this paper, we study the difference of causal and null pseudoconvexity in space-times and introduce the limit geodesic segment as an equivalence condition to the pseudoconvexity. Then, we show that in the case of open subspaces of n-Minkowski space-time, this is causal geodesic connectedness. Finally, we prove a refined form of the conjecture that says every strongly causal space-time is causally simple if and only if it is maximal null pseudoconvex.
Phonon thermal transport in encapsulated copper hybrids
Authors: Tripathi Shivam , Islam Md Mahbubul , Strachan Alejandro
Published: January 2019

We use molecular dynamics simulations to characterize the effect of various surface terminations on phonon thermal transport in nanoscale Cu slabs. Specifically, we studied Cu slabs approximately 4 nm in thickness with atomistically flat (111) surfaces, slabs with ∼30% surface vacancies to mimic atomic-level roughness, and slabs with a surface oxide. Motivated by recent experimental observations, we study the effect of capping these surfaces with single layer graphene. From the thermal conductivity of the various samples as a function of length, we extracted conductivity and phonon mean free paths in the absence of boundary scattering other than that originating from the surfaces under study. As expected, both surface vacancies and an oxide layer reduce thermal conductivity and we characterize the effect in terms of the specularity parameter. While capping the slabs with graphene increases the conductivity, the poor thermal contact between Cu and graphene results in less than ideal performance of the hybrid material. Interestingly, the simulations reveal that the graphene capping layer reduces surface scattering on the Cu slabs, and this effect is significantly more pronounced in the case of a defective surface. The results provide insights into the use of graphene capping to improve transport in nanoscale interconnects for nanoelectronics.
Carbon chemistry variability around a tropical archipelago
Authors: Silva Brenno J. , Gaspar Felipe L. , Tyaquiçã Pedro , Lefèvre Nathalie , Flores Montes Manuel J.
Published: January 2019

Oceanic islands affect the surrounding oceanic circulation by producing upwelling or vortices, resulting in the rising of a richer and colder subsurface water mass. This process increases primary production and can change some biogeochemical processes, such as carbon chemistry and the biological pump. The aim of this study was to describe the vertical variability of carbon chemistry around Fernando de Noronha Archipelago (FNA) and to verify how the island mass effect (IME) can affect carbon distribution. Two transects on opposite sides of the FNA were established according to the direction of the central South Equatorial Current, and samples were collected in July 2010, September 2012 and July 2014 from the surface down to a depth of 500m. The results showed strong stratification, with an uplift of the thermohaline structure, which resulted in an increase of chlorophyll-a concentration downstream of the island during the 2010 and 2014 cruises. Carbon chemistry parameters were strongly correlated with temperature, salinity and dissolved oxygen along the water column and did not change between sides of the island in the periods studied. We conclude that the IME did not significantly affect carbon chemistry, which was more correlated with thermohaline gradient.
Cells exhibiting strong
p16

INK4a

promoter activation in vivo display features of senescence
Authors: Liu Jie-Yu , Souroullas George P. , Diekman Brian O. , Krishnamurthy Janakiraman , Hall Brandon M. , Sorrentino Jessica A. , Parker Joel S. , Sessions Garrett A. , Gudkov Andrei V. , Sharpless Norman E.
Published: January 2019

Significance

The accumulation of senescent cells over a lifetime causes age-related pathologies; however, the inability to reliably identify senescent cells in vivo has hindered clinical efforts to employ this knowledge as a means to ameliorate or reverse aging. Here, we describe a reporter allele,
p16

tdTom

, enabling the in vivo identification and isolation of cells featuring high-level activation of the
p16

INK4a

promoter. Our findings provide an insight into the functional and molecular characteristics of
p16

INK4a

-activated cells in vitro and in vivo. We show that such cells accumulate with aging or other models of injury, and that they exhibit clinically targetable features of cellular senescence.
Higher superconducting transition temperature by breaking the universal pressure relation
Authors: Deng Liangzi , Zheng Yongping , Wu Zheng , Huyan Shuyuan , Wu Hung-Cheng , Nie Yifan , Cho Kyeongjae , Chu Ching-Wu
Published: January 2019

Significance

Achieving higher transition temperature (T
c
) is a primary goal in superconductivity research. T
c
and doping have been found to have a dome-like universal relation where the peak position is the maximum T
c-max
, which is consistent with previous experimental results in the lower pressure range. By using the ultrasensitive magnetization measurement technique under high pressure that we developed, we discovered a universal resurgence of T
c
passing the peak predicted by the general T
c
-
p
(doping) or -P (pressure) relation for cuprate high-temperature superconductor and attribute the resurgence to a pressure-induced electronic transition, which is supported qualitatively by our density functional theory calculations. This offers a paradigm to raise the T
c
of the layered cuprate high-temperature superconductors to a new height.
Now in the historical courtroom
Authors: Claridge Claudia
Published: January 2019

The investigation of the pragmatic marker now in trial proceedings from 1560 to 1800 shows a
genre-specific usage profile with regard to its uses and functions. Courtroom “professionals” (lawyers, judges and other
officials) use now significantly more frequently than lay speakers (witnesses, victims and defendants). The
former use it to segment and highlight stages in the argumentation, as well as to control and to disalign with others’ interactive
behaviour. Self-defending litigants share these functional preferences to some extent, while all other lay persons use
now for structuring their answers and dominantly in direct-speech contexts. Now in
professional legal speech thus functions as a strategic metapragmatic framing strategy.
Typical event sequences as licensors of direct object ellipsis in Russian
Authors: McShane Marjorie
Published: January 2019

This paper extends the computationally-oriented theory of ellipsis presented in McShane’s A Theory of
Ellipsis (2005) by introducing the feature typical event
sequence. It is argued that, in Russian, the presence of a typical sequence of events in a pair of clauses can be the
key feature licensing the ellipsis of the latter’s direct object. The linguistic analysis contributes to a larger cognitive
modeling effort aimed at configuring language-endowed intelligent agents with human-level language understanding capabilities.
Texture homogeneity and stability in severely warm-rolled and annealed ultrafine pearlite
Authors: Narayanswamy S. , Reddy S. R. , Saha R. , Bhattacharjee P. P.
Published: January 2019

The evolution of microstructure and texture was investigated in a severely warm-rolled ultrafine pearlitic steel. The steel was 95% warm-rolled at 600°C and annealed at 700°C for different time intervals. The spheroidisation of cementite initiated after 30% reduction and completed beyond 70% reduction. The 95% warm-rolled steel showed elongated as well as ultrafine equiaxed ferrite grains. Texture inhomogeneities were evidenced by the presence of Goss component ({011} <100>) on the surface originating due to surface shear and diffuse texture at the interior. Formation of equiaxed microstructure after annealing through continuous recrystallisation resulted in the retention of the surface Goss component. However, the Goss component was destroyed beyond annealing for 180 minutes due to the abnormal growth of other grains.
Influence of hold type and duration on cyclic deformation behaviour of IN740H
Authors: Singh R. K. , Sahu J. K.
Published: January 2019

The superimposition of time-dependent damage on fatigue, otherwise, known as creep-fatigue interaction (CFI), significantly affect the fatigue life of power plant boiler components. IN740H is a candidate material for advanced ultra-supercritical (A-USC) boilers components. The creep-fatigue interaction of alloy IN740H was studied at 760°C, by conducting low cycle fatigue (LCF) at a strain amplitude (Δ ϵt/2) value of 0.4% and holding at peak strain in tension, compression and both for 0, 1, 5, 10 and 30 min duration. Though hold time adversely affects fatigue life, tensile hold is the most damaging of all three hold modes. The reason behind maximum damage with tensile hold is grain boundary cavitations and coalescence of cavities leading to internal cracks formation at grain boundaries.
Solute segregation effect on grain boundary migration and Hall–Petch relationship in CrMnFeCoNi high-entropy alloy
Authors: Liu G. , Lu D. H. , Liu X. W. , Liu F. C. , Yang Q. , Du H. , Hu Q. , Fan Z. T.
Published: January 2019

Homogenisation has been used to eliminate solute segregation of CrMnFeCoNi high-entropy alloys (HEAs) before thermomechanical processing. To overcome the deficiencies caused by high-temperature homogenisation, we cancelled the homogenisation and studied the solute segregation feature and its effect on the grain growth and the mechanical property. The HEA forms equiaxed grains with the solute segregation in the range of tens of micrometres after cold rolling and recrystallisation. The grain growth in recrystallisation still abides by the classical grain growth kinetics, but with a higher power index of 3.33 and activation energy of 392.4 kJ mol−1 than those of the homogenised HEA, indicating a solute-drag effect. The relationship between the yield stress and grain size follows the Hall–Petch dependence with a higher intrinsic strength.
Detecting NiTi two-way shape memory effect based on microstructural and macromechanical parameters
Authors: Urbina C. , Gispert F. , Ferrando F. , De la Flor S.
Published: January 2019

The two-way shape memory effect in NiTi shape memory alloys is identified according to the evolution of the apparent modulus of the martensite during mechanical cycling. The microstrain and texture index of the NiTi samples are evaluated with synchrotron data to relate the evolution to the changes in the NiTi microstructure caused by mechanical cycling. The results show that a progressive decrease in the apparent modulus of the martensite during load, together with an increase in the apparent modulus of the reoriented martensite, are a sign that the NiTi sample is developing the two-way memory effect by mechanical cycling. When the two moduli show the same value, the two-way shape memory effect is fully developed in the NiTi alloy.

This paper is part of a thematic issue on Titanium.
Escaping the subject‐based class: A Finnish case study of developing transversal competencies in a transdisciplinary course
Authors: Eronen Lasse , Kokko Sirpa , Sormunen Kari
Published: January 2019

In 2014, the Finnish National Board of Education launched a new core curriculum with the aim of meeting the skills and competence requirements of the 21st century. The purpose of this case study was to find out what transversal competencies Finnish eighth graders developed and how they experienced studying in a problem‐based transdisciplinary course, which was arranged for the transitional stage between the former and the new curriculum. The qualitative data consisted of questionnaires and interviews. The analysis followed the methods of qualitative content analysis. When asked about their learning, the students commented on not having learnt much, referring to the discipline‐based knowledge. Instead, they had learnt skills through teamwork, problem solving, and expression of their views and opinions, an aspect that they did not clearly connect with the things to be learnt at school. Many students felt that they acquired the competencies that they would need later in their lives. The students’ teamwork had a crucial impact on their learning experience. The timeframe for the integrative approach needs careful consideration; the learning process in this course was perceived as being successful because it was long enough. Our study highlights that focusing on students’ views is critical when reforming curriculum.
Use of nonsteroidal anti-inflammatory drugs predicts improved patient survival for PIK3CA-altered head and neck cancer
Authors: Hedberg Matthew L. , Peyser Noah D. , Bauman Julie E. , Gooding William E. , Li Hua , Bhola Neil E. , Zhu Tian Ran , Zeng Yan , Brand Toni M. , Kim Mi-Ok , Jordan Richard C.K. , VandenBerg Scott , Olivas Victor , Bivona Trever G. , Chiosea Simion I. , Wang Lin , Mills Gordon B. , Johnson Jonas T. , Duvvuri Umamaheswar , Ferris Robert L. , Ha Patrick , Johnson Daniel E. , Grandis Jennifer R.
Published: January 2019

PIK3CA is the most commonly altered oncogene in head and neck squamous cell carcinoma (HNSCC). We evaluated the impact of nonsteroidal anti-inflammatory drugs (NSAIDs) on survival in a PIK3CA-characterized cohort of 266 HNSCC patients and explored the mechanism in relevant preclinical models including patient-derived xenografts. Among subjects with PIK3CA mutations or amplification, regular NSAID use (≥6 mo) conferred markedly prolonged disease-specific survival (DSS; hazard ratio 0.23, P = 0.0032, 95% CI 0.09–0.62) and overall survival (OS; hazard ratio 0.31, P = 0.0043, 95% CI 0.14–0.69) compared with nonregular NSAID users. For PIK3CA-altered HNSCC, predicted 5-yr DSS was 72% for NSAID users and 25% for nonusers; predicted 5-yr OS was 78% for regular NSAID users and 45% for nonregular users. PIK3CA mutation predicted sensitivity to NSAIDs in preclinical models in association with increased systemic PGE2 production. These findings uncover a biologically plausible rationale to implement NSAID therapy in PIK3CA-altered HNSCC.