bluuebunny/crossref_metadata_2025 huggingface dataset:
Radiation induced currents in mineral-insulated cables and in pick-up coils: model calculations and experimental verification in the BR1 reactor
Authors: Vermeeren Ludo , Leysen Willem , Brichard Benoit
Published: January 2018

Mineral-insulated (MI) cables and Low-Temperature Co-fired Ceramic (LTCC) magnetic pick-up coils are intended to be installed in various position in ITER. The severe ITER nuclear radiation field is expected to lead to induced currents that could perturb diagnostic measurements. In order to assess this problem and to find mitigation strategies models were developed for the calculation of neutron-and gamma-induced currents in MI cables and in LTCC coils.

The models are based on calculations with the MCNPX code, combined with a dedicated model for the drift of electrons stopped in the insulator. The gamma induced currents can be easily calculated with a single coupled photon-electron MCNPX calculation. The prompt neutron induced currents requires only a single coupled neutron-photon-electron MCNPX run. The various delayed neutron contributions require a careful analysis of all possibly relevant neutron-induced reaction paths and a combination of different types of MCNPX calculations.

The models were applied for a specific twin-core copper MI cable, for one quad-core copper cable and for silver conductor LTCC coils (one with silver ground plates in order to reduce the currents and one without such silver ground plates). Calculations were performed for irradiation conditions (neutron and gamma spectra and fluxes) in relevant positions in ITER and in the Y3 irradiation channel of the BR1 reactor at SCK•CEN, in which an irradiation test of these four test devices was carried out afterwards.

We will present the basic elements of the models and show the results of all relevant partial currents (gamma and neutron induced, prompt and various delayed currents) in BR1-Y3 conditions. Experimental data will be shown and analysed in terms of the respective contributions. The tests were performed at reactor powers of 350 kW and 1 MW, leading to thermal neutron fluxes of 1E11 n/cm2s and 3E11 n/cm2s, respectively. The corresponding total radiation induced currents are ranging from 1 to 7 nA only, putting a challenge on the acquisition system and on the data analysis.

The detailed experimental results will be compared with the corresponding values predicted by the model. The overall agreement between the experimental data and the model predictions is fairly good, with very consistent data for the main delayed current components, while the lower amplitude delayed currents and some of the prompt contributions show some minor discrepancies.
Measurement of plasma current in Tokamaks using an optical fibre reflectometry technique
Authors: Wuilpart Marc , Leysen Willem , Gusarov Andrei , Moreau Philippe , Mégret Patrice
Published: January 2018

An optical time-domain reflectometer sensitive to the polarization of light is proposed for the measurement of plasma current in the Tore Supra fusion reactor. The measurement principle relies on the Faraday effect i.e. on the generation of a circular birefringence along an optical fiber subject to an axial magnetic field. The circular birefringence induces a polarization rotation that can be mapped along the fiber thanks to an opticaltime domain reflectometer followed by an linear polarizer. A proper fitting of the measurement trace then allows determining the applied plasma current. The sensor has been experimentally validated on the Tore Supra tokamak fusion reactor for a plasma current range going from 0.6 to 1.5 MA. A maximum error of 13.50% has been observed for the lowest current.
Suggestion of Design Evaluation Plan based on Star Life Cycle to introduce the Information Minimalism Concept of KOREA Nuclear Plant
Authors: Jang Gwi-sook , Lee Seung-min , Park Gee-yong
Published: January 2018

The design of Korea Nuclear Power Plant (NPP) main control rooms (MCR) has been changed to be fully digitalized. Five or six display devices are assigned to each operator in NPP MCR to provide the information of safety parameter and plant status, and various control functions by connecting computerized control devices. Under this circumstance, the distributed displays can induce a dispersion of the operators’ attention and increase the workload while conducting monitoring and control tasks efficiently. In addition, to support human operators to reduce their workload and increase the performance, the concepts of the ecological interface design (EID) and the operator-centered design were applied to the design HMI display. However these designs are applied to a limited set of screens and did not differ largely from the traditional HMI design in that the layout of the information is somewhere similar to P&IDs.

In this paper, we propose a design evaluation plan based on star life cycle to introduce the information minimalism concept for designing an HMI display.
Design of a delayed neutron detection system for the ASTRID Sodium-cooled fast reactor
Authors: Coulon Romain , Rohée Emmanuel , Dumazert Jonathan , Garti Sara , Filliatre Philippe , Jammes Christian
Published: January 2018

Delayed neutron detection systems are key apparati in Sodium cooled Fast Reactors to prevent safety accidents. Based on the feedbacks from Phenix and Superphenix, DND systems are studied by means of the Monte-Carlo particles transport code MCNP6. Promising designs are proposed and investigated as a result of the simulation study.
Calculations to Support On-line Neutron Spectrum Adjustment by Measurements with Miniature Fission Chambers in the JSI TRIGA Reactor
Authors: Kaiba Tanja , Radulović Vladimir , Žerovnik Gašper , Snoj Luka , Fourmentel Damien , Barbot LoÏc , Destouches Christophe
Published: January 2018

Preliminary calculations were performed with the aim to establish optimal experimental conditions for the measurement campaign within the collaboration between the Jožef Stefan Institute (JSI) and Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA Cadarache). The goal of the project is to additionally characterize the neutron spectruminside the JSI TRIGA reactor core with focus on the measurement epi-thermal and fast part of the spectrum. Measurements will be performed with fission chambers containing different fissile materials (235U, 237Np and 242Pu) covered with thermal neutron filters (Cd and Gd). The changes in the detected signal and neutron flux spectrum with and without transmission filter were studied. Additional effort was put into evaluation of the effect of the filter geometry (e.g. opening on the top end of the filter) on the detector signal. After the analysis of the scoping calculations it was concluded to position the experiment in the outside core ring inside one of the empty fuel element positions.
Impact of the Test Device on the Behavior of the Acoustic Emission Signals: Contribution of the Numerical Modeling to Signal Processing
Authors: Issiaka Traore Oumar , Cristini Paul , Favretto-Cristini Nathalie , Pantera Laurent , Viguier-Pla Sylvie
Published: January 2018

In a context of nuclear safety experiment monitoring with the non destructive testing method of acoustic emission, we study the impact of the test device on the interpretation of the recorded physical signals by using spectral finite element modeling. The numerical results are validated by comparison with real acoustic emission data obtained from previous experiments. The results show that several parameters can have significant impacts on acoustic wave propagation and then on the interpretation of the physical signals. The potential position of the source mechanism, the positions of the receivers and the nature of the coolant fluid have to be taken into account in the definition a pre-processing strategy of the real acoustic emission signals. In order to show the relevance of such an approach, we use the results to propose an optimization of the positions of the acoustic emission sensors in order to reduce the estimation bias of the time-delay and then improve the localization of the source mechanisms.
The CdZnTe Detector with Slit Collimator for Measure Distribution of the Specific Activity Radionuclide in the Ground
Authors: Stepanov V.E. , Volkovich A.G. , Potapov V.N. , Semin I.A. , Stepanov A.V. , Simirskii Iu.N.
Published: January 2018

From 2011 in the NRC "Kurchatov Institute" carry out the dismantling of the MR multiloop research reactor. Now the reactor and all technological equipment in the premises of the reactor were dismantled. Now the measurements of radioactive contamination in the reactor premises are made. The most contaminated parts of premises - floor and the ground beneath it. To measure the distribution of specific activity in the ground the CdZnTe detector (volume 500MM3) was used. Detector placed in a lead shielding with a slit collimation hole. The upper part of shielding is made movable to close and open the slit of the collimator. At each point two measurements carried out: with open and closed collimator. The software for determination specific activity of radionuclides in ground was developed. The mathematical model of spectrometric system based on the Monte-Carlo method. Measurements of specific activity of ground were made. Using the results of measurements the thickness of the removed layer of ground and the amount of radioactive waste were calculated.
Evaluation of a scattering correction method for high energy tomography
Authors: Tisseur David , Bhatia Navnina , Estre Nicolas , Berge Léonie , Eck Daniel , Payan Emmanuel
Published: January 2018

One of the main drawbacks of Cone Beam Computed Tomography (CBCT) is the contribution of the scattered photons due to the object and the detector. Scattered photons are deflected from their original path after their interaction with the object. This additional contribution of the scattered photons results in increased measured intensities, since the scattered intensity simply adds to the transmitted intensity. This effect is seen as an overestimation in the measured intensity thus corresponding to an underestimation of absorption. This results in artifacts like cupping, shading, streaks etc. on the reconstructed images. Moreover, the scattered radiation provides a bias for the quantitative tomography reconstruction (for example atomic number and volumic mass measurement with dual-energy technique). The effect can be significant and difficult in the range of MeV energy using large objects due to higher Scatter to Primary Ratio (SPR). Additionally, the incident high energy photons which are scattered by the Compton effect are more forward directed and hence more likely to reach the detector. Moreover, for MeV energy range, the contribution of the photons produced by pair production and Bremsstrahlung process also becomes important. We propose an evaluation of a scattering correction technique based on the method named Scatter Kernel Superposition (SKS). The algorithm uses a continuously thickness-adapted kernels method. The analytical parameterizations of the scatter kernels are derived in terms of material thickness, to form continuously thickness-adapted kernel maps in order to correct the projections. This approach has proved to be efficient in producing better sampling of the kernels with respect to the object thickness. This technique offers applicability over a wide range of imaging conditions and gives users an additional advantage. Moreover, since no extra hardware is required by this approach, it forms a major advantage especially in those cases where experimental complexities must be avoided. This approach has been previously tested successfully in the energy range of 100 keV – 6 MeV. In this paper, the kernels are simulated using MCNP in order to take into account both photons and electronic processes in scattering radiation contribution. We present scatter correction results on a large object scanned with a 9 MeV linear accelerator.
Remote inspection with multi-copters, radiological sensors and SLAM techniques
Authors: Carvalho Henrique , Vale Alberto , Marques Rúben , Ventura Rodrigo , Brouwer Yoeri , Gonçalves Bruno
Published: January 2018

Activated material can be found in different scenarios, such as in nuclear reactor facilities or medical facilities (e.g. in positron emission tomography commonly known as PET scanning). In addition, there are unexpected scenarios resulting from possible accidents, or where dangerous material is hidden for terrorism attacks using nuclear weapons. Thus, a technological solution is important to cope with fast and reliable remote inspection. The multi-copter is a common type of Unmanned Aerial Vehicle (UAV) that provides the ability to perform a first radiological inspection in the described scenarios. The paper proposes a solution with a multi-copter equipped with on-board sensors to perform a 3D reconstruction and a radiological mapping of the scenario. A depth camera and a Geiger-Müler counter are the used sensors. The inspection is performed in two steps: i) a 3D reconstruction of the environment and ii) radiation activity inference to localise and quantify sources of radiation. Experimental results were achieved with real 3D data and simulated radiation activity. Experimental tests with real sources of radiation are planned in the next iteration of the work.
Nuclear Fuel Assay through analysis of Uranium L-shell by Hybrid L-edge/XRF Densitometer using a Surrogate Material
Authors: Park Seunghoon , Joung Sungyeop , Park Jerry
Published: January 2018

Assay of L-series of nuclear material solution is useful for determination of amount of nuclear materials and ratio of minor actinide in the materials. The hybrid system of energy dispersive X-ray absorption edge spectrometry, i.e. L-edge densitometry, and X-ray fluorescence spectrometry is one of the analysis methods. The hybrid L-edge/XRF densitometer can be a promising candidate for a portable and compact equipment due to advantage of using low energy X-ray beams without heavy shielding systems and liquid nitrogen cooling compared to hybrid K-edge/XRF densitometer.

A prototype of the equipment was evaluated for feasibility ofthe nuclear material assay using a surrogate material (lead) to avoid radiation effects from nuclear materials. The uncertainty of L-edge and XRF characteristics of the sample material and volume effects was discussed in the article.
Development of a Beam Trajectory Monitoring System Using e+/e− Pair Production Events
Authors: KIMURA Shota , EMOTO Yusaku , FUJIHARA Kento , ITO Hiroshi , KAWAI Hideyuki , KOBAYASHI Atsushi , MIZUNO Takahiro
Published: January 2018

In particle therapy, it is important to monitor the Bragg-peak position. It was simulated by GEANT4 Monte Carlo Simulation Code that the distribution of secondary generated gamma rays on the carbon beam therapy and the proton beam therapy. This simulation shows that gamma rays whose energy is 10 MeV or more are intensively generated at the Bragg-peak position. We are developing the system to monitor the Bragg-peak position which can measure pair production events occurred in the detector by gamma rays from irradiation points. The momentum direction of the gamma ray can be determined by measuring passing points and energy of e+ and e− generated by pair production. This system has 5 parts. The first is the conversion part. This part consists of several layers. Each layer is composed of a La-GPS ((Gd0.75La0.24Ce0.01)2Si2O7) scintillator plate and wavelength-shifting fibre (WLSF) sheets. The scintillator plate is sandwiched between sheets, where the directions of the sheets are in orthogonally x and y directions. In this part, gamma rays are converted to e+ e- pairs and the position where the conversion occured is determined. The second is the tracking part. This part consists of 2 layers of scintillating fibre tracker. Each layer has 6 scintillating fibre sheets for x, x’, u, u’, v, and v’. The third is the energy measurement part. It measures the energy of e+ and e− by scintillator array and Silicon Photomultipliers. The fourth is the veto counter for bremsstrahlung gamma rays from e+ and e-. The fifth is the beam monitor. By experiment, the number of photoelectrons of La-GPS with a WLSF (B-3(300)MJ, Kuraray) sheet and scintillating fibre (SCSF-78, Kuraray) when charged particle passed was measured as 9.7 and 7.6 respectively.
Multitude in Cultural Complexities in Asia
Authors: Widodo Johannes
Published: January 2018

The genesis of human settlements is a continuous process of production and layering of patterns, forms and spaces in different scale levels across historical periods. Our urban morphology is the product of the cosmopolitan communities, the articulation of the multi layered tangible and intangible urban traditions and modernization processes. Diversity, eclecticism, fusion, acculturation, adaptation, are the nature of our architecture and urbanism.

However, at present, we are in an urgent need to find resolutions to address serious problems posed by the climate change, ideological conflicts, economic greediness, depletion of resources, and social justice. One of an essential elements in humanity is empathy, and this empathy has been anesthetized or lost due to ignorance and greed in almost all aspects of our relationships with others and nature. The design and planning profession and education should reflect on the mistakes that have been created which have caused cultural, social, and environmental issues. We need to reconsider our present practices, i.e., to reflect on, to interrogate and perhaps to present alternatives to our existing pedagogical paradigm.
The Built Environment of Kampung Arab Sugihwaras Pekalongan
Authors: Wulandari Astari , Mohammadi Loekman , Anwar
Published: January 2018

Since the arrival of Arabian ethnic to Sugihwaras, they settled and built their own neighborhood identity. The built environment is an example of a system on which human beings seek to express their own identity as a collective group. Every built environment consists of distinctive features that relate to social, cultural, economic and environmental parameters inherent in that particular built-environment (Al-Hokail, 1995). Based on that background, the research question of this study is “what is the distinctiveness of built environment in Kampung Arab Sugihwaras Pekalongan?”. The purpose of this article is to identify and explain the built environment in Kampung Arab Sugihwaras by its social and physical parameters. Using both qualitative and quantitative approach, this article examines the social parameters by its four social scales: neighborhood, family and individual, the physicalparameters by its urban fabrics. The result shows that community who lives in Kampung Arab Sugihwaras especially the Arabian descendant preserving Islamic value in their social lives. But, modern urban culture faded some social rules away. While the Kampung Arab Sugihwaras urban fabric shows that neighborhood had grid pattern with two inner main streets and buildings withIndische Architecture style in that corridors. The further result shows the street hierarchy by overlapping the social and physical parameters analysis.
Characteristic Ideal Form to Architecture Traditional Makassar with to Humanist Shelter Development in Settlement Bricks Processor at Gowa Resident, South Sulawesi
Authors: Imriyanti  , Wunas Shirly , Arifin Mimi , Asmal Idawarni J.
Published: January 2018

The ideal form architecture traditional Makassar there is to ideology form, function and architecture mean. Form, function and mean can is known to utilization macro space and micro space at house traditional Makassar. Architecture traditional being culture identity tribes because in there is life society. The society traditional Makassar it is that society still holding long habit by true in daily life. Humanist shelter referring to human needs especially to the occupants, there are human needs that connected with that environment, is sense of security, comfortable, hygienic and economic. The settlement bricks processor at Gowa resident identic with shelter traditional but with growth development in various ways sector than change shelter bricks processor too experiencing good change from at form, function and mean. The settlement bricks processor to Iowa resident at being exactly in Dusun Giring-Giring Kalase Rena village, Bontolangkasa village and Maccini baji village. The change form, function and mean to house/shelter bricks processor than the problem and that found how is ideal form architecture traditional Makassar there is development humanist shelter in settlement risks processor at Gowa resident. This research purpose is element analysis ideal form architecture traditional Makassar that is can to shelter bricks processor at Gowa resident. This research in descriptive explore. The tory character that is done by direct observation to house/shelter bricks processor at Gowa resident. The results of this study that shows ideal form architecture traditional Makassar there is to macro space a house traditional Makassar in settlement bricks processor at Gowa resident. Ideal form to macro space architecturetraditional Makassar there is to house orientation, patterns of home footprint with to utilization as bricks processor at Gowa resident. With utilization macro space at house traditional Makassar can then to form humanist shelter for bricks processor at Gowa resident, South Sulawesi.
The Main Elements of Historical Objects as “Spirit” of Cultural Heritage in Yogyakarta City
Authors: Sari Pawitra , Munandar Aris , Sitti Fatimah Indung
Published: January 2018

The history of Yogyakarta City still holds many “millions” of tangible and intangible meaning. The history has brought Yogyakarta City known as a City of Philosophy that is realized in the spatial layout of the city, one of them is the philosophy axis. In this research, the historical objects have been studied the main elements that become the icon and to be grouped into four objects. There are TuguArea, Malioboro Area, Zero Kilometer Area, and South Square Area located on the philosophy axis.Another consideration, these four objects are supported by other space forming elements become a place that has a “spirit” of cultural heritage to gather and interact with local communities and tourists in the public space. The purpose of this research is enriching knowledge about the main elements of historical objects. Besides that, the purpose of this research is to support Yogyakarta City to realize world Heritage City by UNESCO about cultural heritage. This research uses mix methods. Qualitative methods by conducted the survey and collected the literature. The observation and interviews towards informers and involves the perception of local communities and tourists with 327 respondents in Yogyakarta City. While the quantitative method for a non-parametric test with different test Mann Whitney U using SPSS 17 program. This research uses spatial and descriptive analysis to explain the main elements of historical objects and examine their relationship with local communities and tourists perception. The result of this research that Malioboro Area has the important corridor in historical value that associated with historical events and historical figures, style building, and culture. As well as Malioboro public space that has the meaning of the spirit of life for urban residents and the heart of the city, which means the inheritance of all things. The results of this research are expected to provide of place attachment towards all mainly historical objects “spirits” of cultural heritage for people to gather and interact. The importance of the psychological dimension of the environment to help the psychological well being in urban as a concern for architects, planners in shaping, developing a city in the future, especially public space. Also, the results of this research are expected Yogyakarta City to keep become a magnet for the traveler as Tourism Destination Object.
Understanding the Importance of Time in Interior Architectural Design Method
Authors: Agung Ayu Suci Warakanyaka Anak , Andri Yatmo Yandi
Published: January 2018

The presence of time holds an important position in interior architectural practice and education. On theother hand, the presence of time challenges the stability and steadiness that framed the discipline. Furthermore, in interior architectural practice it is usually seen as a threat that should be either eliminatedor restricted. Rather than establishing defense mechanism against it, this paper argues that interiorarchitectural practice should be able to progress with time. By looking through undergraduate designstudio projects in Interior Architecture Program, Department of Architecture, Universitas Indonesia, this paper aims to addressed how the presence of time might affect, transform and even generate context specific interior architectural design methods that enables several dynamic forms of inhabitation. The out come of this study provides the opportunity for interior discipline to switch its focus, from the discipline that focuses on the aesthetic and constructional aspects, to the one that embraces the temporal aspectsof sociocultural conditions to enhance the wellbeing of its inhabitant.
Recharting The Philosophy of Technology in Contemporary Architecture
Authors: Budi Santosa Revianto
Published: January 2018

Technology is an indispensable aspect of architecture. In fact, it is being an essential part of the human effort in making architecture. Since the early modern era, technology that rapidly change has been seen as the sign of progress, not only pertaining to the technology itself, but also architecture and even civilization. Modern architectural theoreticians, from Sant’Elia to Le Corbusier, enthusiastically embraced the progressive side of technology and engineering. Philosophically, however, modern technology is regarded pessimistically. Heidegger and Jaspers considered technology as the source of alienation to the human being themselves and to the reality they face. To overcome this gap, Alan Drengson, proposed the four philosophy of technology to rechart the variety of tendency towards technology in Western society, consisting of (1) technological anarchy, (2) technophilia, (3) technophobia, and (4) technological appropriateness. In this explanation, he coined the terms “creative philosophy” to include many aspects and ways of thinking which might be incorporated in the creative activities like architectural design. This paper attempts to evaluate the appropriatenes of Drengson’s philosophical scheme as a platform for architectural education in Indonesia in general, by relating his framework with the architectural theories and practices in Indonesia. The result of this effort is while the formulation of his scheme is the very inclusive and closely related with creative activity like architectural design, it contains bias of industrial technology appearing in the Asian scene brought by Western European colonials. Discussing philosophy underlying Gandhi’s movement in India to reject oppressive technology, we may arrive at the conclusion that the philosopy of non-violence, truth and justice based on the principle of self restrained are relevant to figure out the ideal of appropriate technology in Asia.
Learning to Know and Think: Computing for Architecture Course
Authors: Indraprastha Aswin
Published: January 2018

Computational technologies for solving design problems become increasingly important in architecturalpractice. In responding, architectural education has encouraged the use of this tool and method in the curricula. As the technology and environment are ever changing, the curricula should be evaluated and updated to adapt and to teach method and skills necessary to the students. Over the last four years, Architecture Program of ITB has inserted new computational courses into undergraduate levels. These courses are the mix of a skill focused computational workshop that is compulsory for the second-year students and introduction of computational design as an elective course that can be enrolled both by third and fourth year students. This paper delivers a report of our methods and findings from our continuingstudy of the courses including analysis of student outcomes, student evaluation of the course structures, assignments, and feedback as well as computational abilities after completion of the courses. The aim of the study is to have a grounded validation of computational courses in architecture curricula and to improve courses goal based on the evaluation. The result of our study reveals challenging issue to teach computational thinking undergraduate level rather than only providing them a set of computer skills for production and presentation techniques of the design.
Comparative Study of Daylighting Calculation Methods
Authors: Mandala Ariani , Ritva Santoso Amirani
Published: January 2018

The aim of this study is to assess five daylighting calculation method commonly used in architectural study. The methods used include hand calculation methods (SNI/DPMB method and BRE Daylighting Protractors), scale models studied in an artificial sky simulator and computer programs using Dialux and Velux lighting software. The test room is conditioned by the uniform sky conditions, simple room geometry with variations of the room reflectance (black, grey, and white color). The analyses compared the result (including daylight factor, illumination, and coefficient of uniformity value) and examines the similarity and contrast the result different. The color variations trial is used to analyses the internally reflection factor contribution to the result.
Fatigue during Chest Compression Using a Neonatal Patient Simulator
Authors: Enriquez Diego , Meritano Javier , Shah Birju , Song Clara , Szyld Edgardo
Published: January 2018

Objective The objective of this study was to evaluate chest compression (CC) quality and operator fatigue during CC, with coordinated ventilation, on a neonatal simulator and to explore its association with provider aerobic activity and body mass index.

Methods This was a prospective observational experimental study on pediatricians, neonatologists, and neonatal nurses who frequently deliver newborns and who have signed the informed consent. Subjects performed CC coordinated with ventilations at a ratio of 3:1 for 10 minutes on a neonatal mannequin. Proxy of fatigue was defined as four consecutive CC below target.

Results Forty subjects participated; 62% were women. Twenty one (52%) evidenced weariness, as they performed. No gender-based differences were found in weariness. No subject abandoned the procedure due to fatigue. Subjects who participated in aerobic exercise had a significantly better performance than those who did not participate. Early fatigue was significantly associated with higher BMI. The reduction in effectiveness occurred at a mean time of 7.7 minutes (range 3.5–9 minutes).

Conclusion CC performance quality decreased and fatigue was frequent before 10 minutes had elapsed on a neonatal simulator. Provider fatigue was associated with both lack of aerobic activity and BMI ≥ 25. Our findings support the need for guidelines requiring frequent rotation of CC providers during prolonged neonatal resuscitation.
Estimation of thermal stability factor and intrinsic switching current from switching distributions in spin-transfer-torque devices with out-of-plane magnetic anisotropy
Authors: Heindl R. , Chaudhry A. , Russek S. E.
Published: January 2018

We performed macromagnetic simulations of switching statistics in spin-transfer-torque devices with out-of-plane magnetic anisotropy and thermal stability factors ranging from Δ = 21 to Δ = 279. We compared our results of the simulated switching probabilities in low-currents (read-disturb) and long-times (thermally activated) limits with the predictions of several existing models that predict the switching probability to be proportional to (1 − I/Ic0)n (Eq. 3), with exponent n varying from n = 1 to n = 2.2. We found that the best match to the simulated data in these two limits is obtained with values of n ≈ 1.76, when currents are limited to ∼ 0.6-0.8 Ic0.
Efficiency of solution-processed multilayer polymer light-emitting diodes using charge blocking layers
Authors: Kasparek Christian , Rörich Irina , Blom Paul W. M. , Wetzelaer Gert-Jan A. H.
Published: January 2018

By blending semiconducting polymers with the cross-linkable matrix ethoxylated-(4)-bisphenol-a-dimethacrylate (SR540), an insoluble layer is acquired after UV-illumination. Following this approach, a trilayer polymer light-emitting diode (PLED) consisting of a blend of poly[N,N′-bis(4-butylphenyl)-N,N′-bis(phenyl)-benzidine] (poly-TPD) and SR540 as an electron-blocking layer, Super Yellow-Poly(p-phenylene vinylene) (SY-PPV) blended with SR540 as an emissive layer, and poly(9,9-di-n-octylfluorenyl-2,7-diyl) as a hole-blocking layer is fabricated from solution. The trilayer PLED shows a 23% increase in efficiency at low voltage as compared to a single layer SY-PPV PLED. However, at higher voltage, the advantage in current efficiency gradually decreases. A combined experimental and modelling study shows that the increased efficiency is not only due to the elimination of exciton quenching at the electrodes but also due to suppressed nonradiative trap-assisted recombination due to carrier confinement. At high voltages, holes can overcome the hole-blocking barrier, which explains the efficiency roll-off.
Maximizing synchronizability of duplex networks
Authors: Wei Xiang , Emenheiser Jeffrey , Wu Xiaoqun , Lu Jun-an , D'Souza Raissa M.
Published: January 2018

We study the synchronizability of duplex networks formed by two randomly generated network layers with different patterns of interlayer node connections. According to the master stability function, we use the smallest nonzero eigenvalue and the eigenratio between the largest and the second smallest eigenvalues of supra-Laplacian matrices to characterize synchronizability on various duplexes. We find that the interlayer linking weight and linking fraction have a profound impact on synchronizability of duplex networks. The increasingly large inter-layer coupling weight is found to cause either decreasing or constant synchronizability for different classes of network dynamics. In addition, negative node degree correlation across interlayer links outperforms positive degree correlation when most interlayer links are present. The reverse is true when a few interlayer links are present. The numerical results and understanding based on these representative duplex networks are illustrative and instructive for building insights into maximizing synchronizability of more realistic multiplex networks.
Electrodeposited CuSCN metal-semiconductor-metal high performance deep-ultraviolet photodetector
Authors: Lin Hsueh-Pin , Lin Xuan-Jun , Perng Dung-Ching
Published: January 2018

This study reports a low-cost electrodeposited copper(I) thiocyanate (CuSCN) film as a wide band-gap absorber layer for deep-ultraviolet (DUV) photodetector (PD) applications. Electrodeposited CuSCN films deposited with electrolyte concentrations of 24 mM and 33 mM were evaluated as the absorber layers for planar metal-semiconductor-metal PDs. The best photo-responsivity of the CuSCN PD was found to be as high as 70.3 A/W at a −1 V bias under DUV illumination at 300 nm, which corresponded to an external quantum efficiency of 3.1 × 104%. Furthermore, the DUV-to-visible rejection ratio (R300 nm/R400 nm) of ∼103 was realized. This study demonstrated that the CuSCN film has great potential for low-cost DUV PD applications.
Microstructural analysis in the depth direction of a heteroepitaxial AlN thick film grown on a trench-patterned template by nanobeam X-ray diffraction
Authors: Shida K. , Takeuchi S. , Tohei T. , Miyake H. , Hiramatsu K. , Sumitani K. , Imai Y. , Kimura S. , Sakai A.
Published: January 2018

This work quantitatively assessed the three-dimensional distribution of crystal lattice distortions in an epitaxial AlN thick film grown on a trench-patterned template, using nanobeam X-ray diffraction. Position-dependent ω-2θ-φ mapping clearly demonstrated local tilting, spacing and twisting of lattice planes as well as fluctuations in these phenomena on a sub-micrometer scale comparable to the pitch of the trench-and-terrace patterning. Analysis of the crystal lattice distortion in the depth direction was performed using a newly developed method in which the X-ray nanobeam diffracted from the sample surface to specific depths can be selectively detected by employing a Pt wire profiler. This technique generated depth-resolved ω-2θ-φ maps confirming that fluctuations in lattice plane tilting and spacing greatly depend on the dislocation distribution and the history of the AlN epitaxial growth on the trench-patterned structure. It was also found that both fluctuations were reduced on approaching the AlN surface and, in particular, were sharply reduced at specific depths in the terrace regions. These sharp reductions are attributed to the formation of sacrificial zones with degraded crystal quality around the trenches and possibly lead to raising the crystal quality near the surface of the AlN film.
Nonlinear waves in viscoelastic magnetized complex astroplasmas with polarized dust-charge variations
Authors: Das Papari , Karmakar Pralay Kumar
Published: January 2018

A nonextensive nonthermal magnetized viscoelastic astrofluid, compositionally containing nonthermal electrons and ions together with massive polarized dust micro-spherical grains of variable electric charge, is allowed to endure weakly nonlinear perturbation around its equilibrium. The nonextensivity originating from the large-scale non-local effects is included via the Tsallis thermo-statistical distribution laws describing the lighter species. Assuming the equilibrium as a homogeneous hydrostatic one, the dust polarization effects are incorporated via the conventional homogeneous polarization force law. The perturbed fluid model evolves as a unique conjugate pair of coupled extended Korteweg-de Vries (e-KdV) equations. A constructed numerical tapestry shows the collective excitations of a new pair of distinct classes of nonlinear mode structures in new parametric space. The first family indicates periodic electrostatic compressive eigenmodes in the form of soliton-chains. Likewise, the second one reveals gravitational rarefactive solitary patterns. Their microphysical multi-parametric dependencies of the eigen-patterns are illustratively analyzed and bolstered. The paper ends up with some promising implications and applications in the astro-cosmo-plasmic context of wave-induced accretive triggering processes responsible for gravitationally bounded (gravito-condensed) astro-structure formation, such as stellesimals, planetsimals, etc.
Giant tunnel magnetoresistance in polycrystalline magnetic tunnel junctions with highly textured MgAl2O4(001) based barriers
Authors: Ikhtiar  , Sukegawa Hiroaki , Xu Xiandong , Belmoubarik Mohamed , Lee Hwachol , Kasai Shinya , Hono Kazuhiro
Published: January 2018

Although single-crystalline spinel (MgAl2O4)-based magnetic tunnel junctions (MTJs) are known to show a good bias voltage dependence of a tunnel magnetoresistance (TMR) ratio over MgO-based MTJs, no polycrystalline MgAl2O4-based MTJs exhibiting large TMR ratios have been grown previously due to the lack of crystallinity of the MgAl2O4 barrier. In this work, we demonstrate the growth of polycrystalline-based MTJs with large TMR ratios exceeding 240% and an improved bias voltage dependence compared to that of MgO-based MTJs. An ultra-thin CoFe/MgO seed layer on the amorphous CoFeB layer induced the growth of a highly (001)-textured MgAl2O4 barrier, which worked as a template layer for the solid epitaxy of CoFe grains during the crystallization of the CoFeB layers. High resolution scanning transmission electron microscopy shows lattice-matched epitaxy between the (001)-textured MgAl2O4 barrier and CoFe grains. This study demonstrates the industrial viability of MgAl2O4-based polycrystalline MTJs with an improved bias voltage dependence.
Radiation hardness of β-Ga2O3 metal-oxide-semiconductor field-effect transistors against gamma-ray irradiation
Authors: Wong Man Hoi , Takeyama Akinori , Makino Takahiro , Ohshima Takeshi , Sasaki Kohei , Kuramata Akito , Yamakoshi Shigenobu , Higashiwaki Masataka
Published: January 2018

The effects of ionizing radiation on β-Ga2O3 metal-oxide-semiconductor field-effect transistors (MOSFETs) were investigated. A gamma-ray tolerance as high as 1.6 MGy(SiO2) was demonstrated for the bulk Ga2O3 channel by virtue of weak radiation effects on the MOSFETs' output current and threshold voltage. The MOSFETs remained functional with insignificant hysteresis in their transfer characteristics after exposure to the maximum cumulative dose. Despite the intrinsic radiation hardness of Ga2O3, radiation-induced gate leakage and drain current dispersion ascribed respectively to dielectric damage and interface charge trapping were found to limit the overall radiation hardness of these devices.
Overexpression of the transcription factor Rst2 inSchizosaccharomyces pombeindicates growth defect, mitotic defects, and microtubule disorder
Authors: Takenaka Kouhei , Tanabe Takuma , Kawamukai Makoto , Matsuo Yasuhiro
Published: January 2018

In Schizosaccharomyces pombe, the transcription factor Rst2 regulates ste11 in meiosis and fbp1 in glucogenesis downstream of the cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA) pathway. Here, we demonstrate that Rst2 regulates additional cellular events. Overexpressed Rst2 elevated the frequency of oval, bent, branched, septated, and multi-septated cells. Cells showed normal nuclear divisions but exhibited abnormal nuclear organization at low frequency. In oval cells, microtubules were curved but they were rescued by the deletion of mal3. Since growth defect was not rescued by mal3 deletion, we argue that it is regulated independently. Loss of functional Pka1 exaggerated growth defect upon Rst2 overexpression because its downregulation by Pka1 was lost. Overexpression of Rst2 also caused sensitivity to KCl and CaCl2. These findings suggest that, in addition to meiosis and glucogenesis, Rst2 is involved in cellular events such as regulation of cell growth, cell morphology, mitosis progression, microtubules structure, nuclear structure, and stress response.
Ileal mucosal response to the same probiotic Lactobacillus strains is markedly different between suckling and adult mice
Authors: Inoue Ryo , Fujiwara Shigeru , Tsukahara Takamitsu
Published: January 2018

While evidence shows that probiotic supplementation exerts beneficial effects on developing children and animals, it is unclear whether it would exert equal or similar effects on adult human and animals. In this study, response to probiotic lactobacilli in ileal mucosa of suckling and adult mice was compared by evaluating gene expression profiles using DNA microarray. Two probiotic strains, Lactobacillus gasseri CP2305s and Lactobacillus plantarum CPA305C were used. Supplementation of probiotics for 7 days affected completely different genes in suckling and adult mice, regardless of the probiotic strain. The results suggested that ileal mucosal responses to probiotics are age stage specific.
Myosin II–interacting guanine nucleotide exchange factor promotes bleb retraction via stimulating cortex reassembly at the bleb membrane
Authors: Jiao Meng , Wu Di , Wei Qize
Published: January 2018

Blebs are involved in various biological processes such as cell migration, cytokinesis, and apoptosis. While the expansion of blebs is largely an intracellular pressure-driven process, the retraction of blebs is believed to be driven by RhoA activation that leads to the reassembly of the actomyosin cortex at the bleb membrane. However, it is still poorly understood how RhoA is activated at the bleb membrane. Here, we provide evidence demonstrating that myosin II–interacting guanine nucleotide exchange factor (MYOGEF) is implicated in bleb retraction via stimulating RhoA activation and the reassembly of an actomyosin network at the bleb membrane during bleb retraction. Interaction of MYOGEF with ezrin, a well-known regulator of bleb retraction, is required for MYOGEF localization to retracting blebs. Notably, knockout of MYOGEF or ezrin not only disrupts RhoA activation at the bleb membrane, but also interferes with nonmuscle myosin II localization and activation, as well as actin polymerization in retracting blebs. Importantly, MYOGEF knockout slows down bleb retraction. We propose that ezrin interacts with MYOGEF and recruits it to retracting blebs, where MYOGEF activates RhoA and promotes the reassembly of the cortical actomyosin network at the bleb membrane, thus contributing to the regulation of bleb retraction.
Analysis of the Aedes albopictus C6/36 genome provides insight into cell line utility for viral propagation
Authors: Miller Jason R , Koren Sergey , Dilley Kari A , Puri Vinita , Brown David M , Harkins Derek M , Thibaud-Nissen Françoise , Rosen Benjamin , Chen Xiao-Guang , Tu Zhijian , Sharakhov Igor V , Sharakhova Maria V , Sebra Robert , Stockwell Timothy B , Bergman Nicholas H , Sutton Granger G , Phillippy Adam M , Piermarini Peter M , Shabman Reed S
Published: January 2018

Background

The 50-year-old Aedes albopictus C6/36 cell line is a resource for the detection, amplification, and analysis of mosquito-borne viruses including Zika, dengue, and chikungunya. The cell line is derived from an unknown number of larvae from an unspecified strain of Aedes albopictus mosquitoes. Toward improved utility of the cell line for research in virus transmission, we present an annotated assembly of the C6/36 genome.

Results

The C6/36 genome assembly has the largest contig N50 (3.3 Mbp) of any mosquito assembly, presents the sequences of both haplotypes for most of the diploid genome, reveals independent null mutations in both alleles of the Dicer locus, and indicates a male-specific genome. Gene annotation was computed with publicly available mosquito transcript sequences. Gene expression data from cell line RNA sequence identified enrichment of growth-related pathways and conspicuous deficiency in aquaporins and inward rectifier K+ channels. As a test of utility, RNA sequence data from Zika-infected cells were mapped to the C6/36 genome and transcriptome assemblies. Host subtraction reduced the data set by 89%, enabling faster characterization of nonhost reads.

Conclusions

The C6/36 genome sequence and annotation should enable additional uses of the cell line to study arbovirus vector interactions and interventions aimed at restricting the spread of human disease.
Host responses to intestinal nematodes
Authors: Yasuda Koubun , Nakanishi Kenji
Published: January 2018

Helminth infection remains common in developing countries, where residents who suffer from the consequences of such infections can develop serious physical and mental disorders and often persist in the face of serious economic problems. Intestinal nematode infection induces the development of Th2-type immune responses including the B-cell IgE response; additionally, this infection induces an increase in the numbers and activation of various types of effector cells, such as mast cells, eosinophils and basophils, as well as the induction of goblet cell hyperplasia, anti-microbial peptide production and smooth-muscle contraction, all of which contribute to expel nematodes. Innate immunity is important in efforts to eliminate helminth infection; cytokines, including IL-25, IL-33 and thymic stromal lymphopoietin, which are products of epithelial cells and mast cells, induce Th2 cells and group 2 innate lymphoid cells to proliferate and produce Th2 cytokines. Nematodes also facilitate chronic infection by suppression of immune reactions through an increased number of Treg cells. Immunosuppression by parasite infection may ultimately be beneficial for the host animals; indeed, a negative correlation has been found between parasite infection and the prevalence of inflammatory disease in humans.